JP7753833B2 - Transmitting device and electronic device - Google Patents

Description

This disclosure relates to a transmitting device and an electronic device.

Conventionally, there has been a transmission device that includes a first modulation unit that mixes a first baseband signal with an intermediate frequency signal to generate a second baseband signal, and a second modulation unit that mixes the second baseband signal with a local oscillation signal to generate a high-frequency signal, where the frequency of the local oscillation signal is the sum or difference of the carrier frequency of the high-frequency signal and the frequency of the intermediate frequency signal (see, for example, Patent Document 1).

JP 2014-236491 A

Semiconductor devices implemented using semiconductors are often used in circuits such as amplifiers in such transmitters, but there is an upper limit to the frequency at which semiconductor devices can operate. Therefore, if there is a need to operate a transmitter in a frequency band that exceeds the upper limit frequency of the semiconductor device, conventional transmitters cannot be used.

The objective is to provide a transmitter and electronic device that can output a transmission signal in a frequency band that exceeds the upper frequency limit of a semiconductor device.

The transmitting device of the present disclosure includes a signal source that outputs a local signal of a first frequency, a first amplifier that amplifies the local signal output from the signal source, a first mixer that mixes a first input signal of an intermediate frequency with the local signal amplified by the first amplifier to output a first output signal, and a second mixer that mixes the first output signal output from the first mixer with the local signal amplified by the first amplifier to output a second output signal.

It is possible to provide a transmitter and electronic device that can output a transmission signal in a frequency band that exceeds the upper frequency limit of the semiconductor device.

1 is a diagram showing a configuration of an electronic device 10 including a transmission device 100 according to a first embodiment. FIG. 2 is a diagram illustrating an example of a circuit configuration of a mixer 130. 2 is a diagram showing output signals RF1 and RF2 of mixers 130 and 140. FIG. FIG. 10 is a diagram showing a configuration of an electronic device 10M including a transmission device 100M according to a modification of the first embodiment. FIG. 10 is a diagram showing the configuration of an electronic device 20 including a transmitting device 200 according to a second embodiment. 10 is a diagram showing an output signal RF1 of the mixer 130 and a transmission signal RF output from the HPF 150. FIG. FIG. 10 is a diagram showing a configuration of an electronic device 20M1 including a transmission device 200M1 according to a first modified example of the second embodiment. FIG. 10 is a diagram showing a configuration of an electronic device 20M2 including a transmission device 200M2 according to a second modification of the second embodiment. 10 is a diagram showing an output signal RF1 of the mixer 130 and a transmission signal RF output from the HPF 150. FIG. FIG. 2 is a diagram illustrating a simulation model of the transmitting device 100 according to the first embodiment. FIG. 10 is a diagram illustrating a simulation result for the transmitting device 100 according to the first embodiment. FIG. 10 is a diagram illustrating a simulation model of a transmission device 100M according to a modified example of the first embodiment. FIG. 10 is a diagram illustrating a simulation result for a transmission device 100M according to a modified example of the first embodiment. FIG. 10 is a diagram showing an example of the configuration of an electronic device 30 including a transmitting device 300 according to a third embodiment. 3A to 3C are diagrams showing examples of waveforms of signals obtained at each section of the transmitting device 300. FIG. 11 is a diagram showing an example of the configuration of an electronic device 30M including a transmission device 300M according to a modification of the third embodiment. 3A to 3C are diagrams showing examples of waveforms of signals obtained at each part of the transmitting device 300M.

The following describes embodiments in which the disclosed transmitter and electronic device are applied.

<Embodiment 1>
1 is a diagram showing the configuration of an electronic device 10 including a transmission device 100 according to embodiment 1. The electronic device 10 includes a data output unit 50 and the transmission device 100. The electronic device 10 is, for example, a smartphone, a tablet computer, or any other portable device having a communication function.

The data output unit 50 is realized by a computer including a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), an input/output interface, an internal bus, etc. The data output unit 50 has an output terminal 51, which is connected to the input terminal 101 of the transmitting device 100. The data output unit 50 generates an IF (Intermediate Frequency) signal based on data generated by the operation of the electronic device 10 and outputs it from the output terminal 51. The frequency of the IF signal is, for example, 10 GHz. The IF signal is an example of a first intermediate frequency input signal.

Transmitting device 100 has input terminal 101, output terminal 102, signal source 110, amplifiers 121 and 122, mixers 130 and 140, and HPF (High Pass Filter) 150. Amplifiers 121 and 122 are examples of first amplifiers. Here, a configuration in which the first amplifier has two amplifiers 121 and 122 will be described. Mixers 130 and 140 are examples of a first mixer and a second mixer, respectively. Mixers 130 and 140 are provided in two stages for the IF signal.

Outside the transmitting device 100, the input terminal 101 is connected to the output terminal 51 of the data output unit 50, and an IF signal is input from the data output unit 50. Inside the transmitting device 100, the input terminal 101 is connected to one input terminal of the mixer 130.

Output terminal 102 is connected to the output terminal of HPF 150 inside transmitting device 100, and is connected to antenna 103 outside transmitting device 100. Output terminal 102 is a terminal that outputs a transmission signal RF (Radio Frequency) obtained by transmitting device 100 performing frequency conversion and amplification on the IF signal. The transmission signal RF is transmitted from antenna 103. Note that a circuit that performs, for example, impedance matching or other processing may be provided between output terminal 102 and antenna 103.

Signal source 110 outputs a local signal (LO). The frequency of the local signal is, for example, 150 GHz. The frequency of the local signal is an example of a first frequency. 150 GHz is close to the upper limit of the frequency of signals that can be amplified by amplifiers 121 and 122, which are realized using HEMTs (High Electron Mobility Transistors). However, it is a frequency at which HEMTs can operate as amplifiers 121 and 122 with good amplification characteristics. The output terminal of signal source 110 is connected to the input terminals of amplifiers 121 and 122. For example, a PLL (Phase Locked Loop) synthesizer can be used as such signal source 110.

Amplifier 121 has an input terminal connected to signal source 110 and an output terminal connected to the other input terminal of mixer 130, and amplifies the local signal input from signal source 110 and outputs it to mixer 130. As an example, amplifier 121 is realized by a HEMT.

Amplifier 122 has an input terminal connected to signal source 110 and an output terminal connected to one input terminal of mixer 140, and amplifies the local signal input from signal source 110 and outputs it to mixer 140. Similar to amplifier 121, amplifier 122 can be realized, for example, by a HEMT. The amplification factor (gain) of amplifier 122 may be the same as or different from the amplification factor of amplifier 121.

Furthermore, although the configuration in which local signals amplified by two amplifiers 121 and 122 are input to mixers 130 and 140 is described here, a single amplifier may also be used. The local signal output from signal source 110 may also be amplified by a single amplifier, then branched and input to mixers 130 and 140.

Mixer 130 has two input terminals connected to input terminal 101 and the output terminal of amplifier 121, and an output terminal connected to the other input terminal of mixer 140. Mixer 130 mixes the IF signal input from input terminal 101 with the local signal amplified by amplifier 121, and outputs the result to mixer 140 as output signal RF1. Output signal RF1 is an example of a first output signal. Therefore, if the frequency of the local signal is LO and the frequency of the IF signal is IF, the frequency of output signal RF1 is LO±IF. Frequencies LO±IF are a band including 150 GHz. As an example, mixer 130 is realized using a HEMT.

Mixer 140 has two input terminals connected to the output terminal of mixer 130 and the output terminal of amplifier 122, and an output terminal connected to the input terminal of HPF 150. Mixer 140 mixes output signal RF1 input from mixer 130 with the local signal amplified by amplifier 122, and outputs the result to HPF 150 as output signal RF2. Output signal RF2 is an example of a second output signal. Therefore, the frequency of output signal RF2 is 2×LO±IF. The frequency 2×LO±IF is a band including 300 GHz. The band including 300 GHz is an example of a band including a second frequency that is twice the first frequency. Note that mixer 140 is implemented, as an example, using a HEMT.

In this way, by mixing the local signal twice with the IF signal using two mixers 130 and 140, an output signal RF2 with twice the frequency of the local signal output from signal source 110 is obtained. The output sources of the local signals mixed twice with the IF signal are both the same signal source 110, and because local signals of the same frequency are mixed twice, the generation of extraneous frequency components is suppressed, and an output signal RF2 with a 300 GHz band, twice the frequency of the original local signal, is obtained. If the signal sources of the local signals mixed twice were different, there is a possibility that extraneous frequency components would be included in output signal RF2 due to errors in the frequencies of the local signals output by the two signal sources 110. However, by combining the local signal output from a single signal source 110 twice, an output signal RF2 with a frequency that is doubled with high precision can be obtained.

HPF 150 has an input terminal connected to the output terminal of mixer 140, and an output terminal connected to output terminal 102. HPF 150 has a cutoff frequency that allows the frequency of output signal RF2, 2 x LO ± IF (300 GHz band), to pass through. The cutoff frequency is slightly lower than 2 x LO - IF. By using such an HPF 150, it is possible to remove components in the 150 GHz band that may be contained in output signal RF2, as well as other unnecessary frequency components, and efficiently extract components in the 2 x LO ± IF frequency band (300 GHz band).

Figure 2 shows an example of the circuit configuration of mixer 130. Since mixers 130 and 140 have the same circuit configuration, only mixer 130 will be described here. As shown in Figure 2(A), mixer 130 includes, as an example, a HEMT 130A, two input terminals 131 and 132, one output terminal 133, an LPF (Low Pass Filter) 134, and an HPF 135.

The drain D of the HEMT is connected to input terminal 131 via LPF 134, and to input terminal 132 via HPF 135. The gate G of HEMT 130A is connected to output terminal 133, and the source S of HEMT 130A is grounded. A mixer 130 having such a connection structure for HEMT 130A constitutes a drain local injection mixer.

Input terminal 131 is connected to input terminal 101 (see Figure 1) and receives an IF signal, while input terminal 132 is connected to the output terminal of amplifier 121 (see Figure 1) and receives a local signal (LO) amplified by amplifier 121. Output terminal 133 is connected to the other input terminal of mixer 140. HEMT 130A shown in Figure 2(A) receives an IF signal and a local signal at drain D and outputs output signal RF1 from gate G. The frequency of output signal RF1 is LO ± IF. Such a drain local injection mixer may be used as mixers 130 and 140.

In addition, the mixer 130 shown in FIG. 2(B) may be used instead of the mixer 130 shown in FIG. 2(A). The mixer 130 shown in FIG. 2(B) has a configuration in which the input terminal 132 and output terminal 133 shown in FIG. 2(A) are swapped. The HEMT 130A shown in FIG. 2(B) forms a resistive mixer. Note that, like the HEMT 130A in FIG. 2(A), the input terminal 131, the input terminal 132, and the output terminal 133 are connected to the input terminal 101, the output terminal of the amplifier 121 (see FIG. 1), and the other input terminal of the mixer 140, respectively.

HEMT 130A shown in Figure 2(B) receives an IF signal at drain D and a local signal at gate G, and outputs output signal RF1 from drain D. The frequency of output signal RF1 is LO ± IF. Such a resistive mixer may be used as mixers 130 and 140.

Figure 3 shows the output signals RF1 and RF2 of mixers 130 and 140. In Figure 3, the horizontal axis represents frequency, and the vertical axis represents signal strength. The output signals RF1 and RF2 also contain a 10 GHz component of the IF signal, but this is omitted here.

As shown in Figure 3, mixer 130 generates output signal RF1 (LO ± IF) around 150 GHz, and mixer 140 generates output signal RF2 (2 x LO ± IF) around 300 GHz. In this way, by mixing the IF signal twice with local signals of the same frequency in two stages of mixers 130 and 140, output signal RF2 in the 300 GHz band can be obtained. Output signal RF2 passes through HPF 150, which removes unnecessary frequency components, and is output from output terminal 102 as a transmit signal RF in the 300 GHz band.

As described above, by mixing two local signals of the same frequency output from the same signal source 110 with the IF signal in two stages of mixers 130 and 140, a 300 GHz band output signal RF2 can be obtained using a 150 GHz local signal. Because the local signals output from the same signal source 110 and amplified by amplifiers 121 and 122 are supplied to mixers 130 and 140, the frequencies of the two local signals supplied to mixers 130 and 140 are exactly equal at 150 GHz. Therefore, a 300 GHz band output signal RF2 can be generated with high precision using a 150 GHz local signal, which is below the upper limit frequency that amplifiers 121 and 122, realized using HEMTs, can amplify. The extraneous frequency components contained in output signal RF2 can then be removed by HPF 150 and output from output terminal 102 as the transmit signal RF.

Therefore, it is possible to provide a transmitter device 100 and electronic device 10 that can output a transmission signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device.

Furthermore, to obtain output signal RF2 from mixer 140, two 150 GHz local signals with exactly the same frequency are supplied to mixers 130 and 140. These signals are output from the same signal source 110 and amplified by amplifiers 121 and 122, respectively. This suppresses the generation of unnecessary frequency components, making it possible to obtain output signal RF2 and transmission signal RF of 300 GHz with high precision and minimal error.

The 300 GHz band is a promising frequency band for 6G (Sixth Generation) next-generation communications. However, it is difficult to realize semiconductor circuits that operate at frequencies as high as 300 GHz. Even when using transistors with high electron mobility such as HEMTs, the upper limit of signal frequencies that can be amplified with good amplification characteristics by amplifiers 121 and 122 is only slightly higher than 150 GHz.

For this reason, it is difficult to combine an IF signal and a 300 GHz local signal using a single mixer, for example, because it is not realistic to create an amplifier capable of amplifying a 300 GHz local signal.

Also possible is a circuit that outputs a 300 GHz transmit signal by amplifying a 100 GHz or 150 GHz local signal with an amplifier implemented using a HEMT, mixing the IF signal with the amplified local signal in a single mixer, and then tripling or doubling the frequency of the resulting output signal with a multiplier. However, in this case, the bandwidth of the IF signal is also tripled or doubled (3 x IF or 2 x IF), making it impossible to obtain an output signal RF2 with a frequency of 2 x LO ± IF as in the first embodiment described above. The IF signal components become ±3 IF or ±2 IF. Multipliers also have the problem of high conversion loss. As an example, the conversion loss of mixers 130 and 140 is -10 dB, while the conversion loss of the multiplier is -20 dB.

From this perspective, it can be said that the transmitter 100, which supplies two 150 GHz local signals with identical frequencies output from the same signal source 110, amplified by amplifiers 121 and 122, respectively, to mixers 130 and 140, achieves extremely efficient frequency conversion and amplification. Furthermore, this configuration enables the generation of a 300 GHz output signal RF2 and a transmission signal RF with high precision and minimal error.

In addition, the inclusion of HPF 150 on the output side of mixer 140 makes it possible to efficiently and easily remove 150 GHz band components that may be included in output signal RF2, enabling a high-quality 300 GHz band transmission signal RF to be output.

Figure 4 is a diagram showing the configuration of electronic device 10M including a transmission device 100M according to a modified example of embodiment 1. Electronic device 10M includes a data output unit 50 and transmission device 100M. Like electronic device 10, electronic device 10M is, for example, a smartphone, tablet computer, or other portable device with communication capabilities.

Transmitting device 100M differs from transmitting device 100 of embodiment 1 in that an amplifier 160 is added between mixer 130 and mixer 140. Other configurations are the same as those of transmitting device 100 of embodiment 1, so only the differences will be explained here.

Amplifier 160 is an example of a second amplifier. Amplifier 160 has an input terminal connected to the output terminal of mixer 130 and an output terminal connected to the input terminal of mixer 140. Like amplifiers 121 and 122, amplifier 160 is realized, for example, by a HEMT. Amplifier 160 further amplifies output signal RF1 output from mixer 130 and outputs it to mixer 140. After being combined by mixer 140, the operation is the same as that of transmitting device 100 in embodiment 1.

Therefore, it is possible to provide a transmitting device 100M and electronic device 10M that are capable of outputting a transmission signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device. Furthermore, because the transmitting device 100M includes an amplifier 160 between the mixer 130 and the mixer 140, the output of the transmission signal RF can be further increased. The amplification factor of the amplifier 160 can be set to an appropriate value depending on the application of the transmitting device 100M, etc.

<Embodiment 2>
5 is a diagram showing the configuration of an electronic device 20 including a transmission device 200 according to embodiment 2. The electronic device 20 includes a data output unit 50 and the transmission device 200. Like the electronic device 10, the electronic device 20 is, for example, a smartphone, a tablet computer, or other portable device having a communication function.

In embodiment 2, the data output unit 50 has two output terminals 51A and 51B, which output an I signal and a Q signal, respectively. The I signal is the real component of the IF signal, and the Q signal is the imaginary component of the IF signal. The Q signal is 90 degrees out of phase with respect to the I signal. The I signal is an example of a first input signal, and the Q signal is an example of a second input signal of intermediate frequency that has a phase that differs by 90 degrees from the first input signal.

The transmitting device 200 has input terminals 201A and 201B, an output terminal 202, a signal source 110, amplifiers 221, 222, 223, and 224, mixers 130, 140, 230, and 240, an HPF 150, a phase shifter 270, and an adder 280. The mixers 130, 140, 230, and 240 are provided in two stages with two systems for the I signal and the Q signal. Here, components similar to those in the transmitting device 100 of embodiment 1 are designated by the same reference numerals, and their description will be omitted.

Amplifiers 221, 222, 223, and 224 are examples of first amplifiers. Here, a configuration in which the first amplifier has four amplifiers 221, 222, 223, and 224 is described. Mixers 130, 140, 230, and 240 are examples of a first mixer, a second mixer, a third mixer, and a fourth mixer, respectively.

Outside the transmitting device 200, the input terminal 201A is connected to the output terminal 51A of the data output unit 50, and an I signal is input from the data output unit 50. Inside the transmitting device 200, the input terminal 201A is connected to one input terminal of the mixer 130.

Outside the transmitting device 200, the input terminal 201B is connected to the output terminal 51B of the data output unit 50, and the Q signal is input from the data output unit 50. Inside the transmitting device 200, the input terminal 201B is connected to one input terminal of the mixer 230.

Output terminal 202 is connected to the output terminal of HPF 150 inside transmitting device 200, and is connected to antenna 103 outside transmitting device 200. Output terminal 202 is a terminal that outputs the transmission signal RF obtained by transmitting device 200 performing frequency conversion and amplification on the IF signal. Note that a circuit for performing impedance matching or other processing, for example, may be provided between output terminal 202 and antenna 103.

Signal source 110 outputs a local signal (LO). The frequency of the local signal is, for example, 150 GHz. 150 GHz is close to the upper limit of the frequency of signals that can be amplified by amplifiers 221, 222, 223, and 224, which are realized using HEMTs, but it is a frequency at which HEMTs can operate as amplifiers 221, 222, 223, and 224 with good amplification characteristics. The output terminal of signal source 110 is connected to the input terminals of amplifiers 221, 222, 223, and 224.

The amplifier 221 is similar to the amplifier 121 in embodiment 1, and has an input terminal connected to the signal source 110 and an output terminal connected to the other input terminal of the mixer 130. It amplifies the local signal input from the signal source 110 and outputs it to the mixer 130. The amplifier 221 is realized by a HEMT.

Amplifier 222 is similar to amplifier 122 in embodiment 1, and has an input terminal connected to signal source 110 and an output terminal connected to one input terminal of mixer 140. It amplifies the local signal input from signal source 110 and outputs it to mixer 140. Note that amplifier 222 can be realized using a HEMT, just like amplifier 221. The amplification factor of amplifier 222 may be the same as or different from the amplification factor of amplifier 221.

Amplifier 223 has an input terminal connected to signal source 110 and an output terminal connected to the other input terminal of mixer 230, and amplifies the local signal input from signal source 110 and outputs it to mixer 230. Amplifier 223 is implemented using a HEMT. It is preferable to set the gain of amplifier 223 to the same value as the gain of amplifier 221, taking into account the symmetry of the circuit.

Amplifier 224 has an input terminal connected to signal source 110 and an output terminal connected to one of the input terminals of mixer 240, and amplifies the local signal input from signal source 110 and outputs it to mixer 240. It is preferable to set the gain of amplifier 224 to the same value as that of amplifier 221, taking into account the symmetry of the circuit.

Furthermore, although the configuration described here is one in which local signals amplified by four amplifiers 221, 222, 223, and 224 are input to mixers 130, 140, 230, and 240, a single amplifier may also be used. The local signal output from signal source 110 may also be amplified by a single amplifier, then branched and input to mixers 130, 140, 230, and 240.

Mixer 130 has two input terminals connected to input terminal 201A and the output terminal of amplifier 221, and an output terminal connected to the other input terminal of mixer 140. Mixer 130 mixes the I signal input from input terminal 201A with the local signal amplified by amplifier 221, and outputs the result to mixer 140 as output signal RF1. Output signal RF1 is an example of a first output signal. Therefore, the frequency of output signal RF1 is LO±IF. Frequencies LO±IF are a band including 150 GHz. The frequency of the I signal is IF.

Mixer 140 has two input terminals connected to the output terminal of mixer 130 and the output terminal of amplifier 222, and an output terminal connected to one input terminal of adder 280. Mixer 140 mixes output signal RF1 input from mixer 130 with the local signal amplified by amplifier 222, and outputs the result to adder 280 as output signal RF2. Output signal RF2 is an example of a second output signal. Therefore, the frequency of output signal RF2 is 2 x LO ± IF. The frequency 2 x LO ± IF is a band that includes 300 GHz.

Mixer 230 has two input terminals connected to input terminal 201B and the output terminal of amplifier 223, and an output terminal connected to the other input terminal of mixer 240. Mixer 230 mixes the Q signal input from input terminal 201B with the local signal amplified by amplifier 223, and outputs the result as output signal RF3 to mixer 140. Output signal RF3 is an example of a third output signal. Therefore, the frequency of output signal RF3 is LO±IF. Frequencies LO±IF are a band including 150 GHz. The frequency of the Q signal is IF.

Mixer 240 has two input terminals connected to the output terminal of mixer 230 and the output terminal of amplifier 224, and an output terminal connected to the input terminal of phase shifter 270. Mixer 240 mixes output signal RF3 input from mixer 230 with the local signal amplified by amplifier 224, and outputs the result as output signal RF4 to phase shifter 270. Output signal RF4 is an example of a fourth output signal. Therefore, the frequency of output signal RF4 is 2 x LO ± IF. The frequency 2 x LO ± IF is a band that includes 300 GHz.

Phase shifter 270 has an input terminal connected to the output terminal of mixer 240 and an output terminal connected to the other input terminal of adder 280, and outputs the output signal RF4 input from mixer 240 with the phase advanced by 90 degrees. As a result, the output signal RF4, which is phase-shifted by phase shifter 270 and output, is in phase with the output signal RF2. In this way, phase shifter 270 aligns the phases of output signal RF4 and output signal RF2. As an example, a transmission line having a length of 1/4 the wavelength at the frequency of output signal RF4 can be used as such phase shifter 270. It is sufficient to advance the phase by 90 degrees using such a transmission line.

Adder 280 has two input terminals connected to the output terminal of mixer 140 and the output terminal of phase shifter 270, and an output terminal connected to the input terminal of HPF 150. Adder 280 adds output signal RF2 input from mixer 140 and output signal RF4 input after its phase has been advanced by 90 degrees by phase shifter 270.

Here, the angular velocity of the IF signal is ω _IF and the angular velocity of the local signal is ω _LO . The frequency obtained at the angular velocity ω _LO is 150 GHz. If the I signal is cos(ω _IF · t) and the Q signal is sin(ω _IF · t), the output signal RF1 is cos(ω _LO + ω _IF ) t + cos(ω _LO - ω _IF ) t, and the output signal RF2 is cos(2ω _LO + ω _IF ) t + cos(2ω _LO - ω _IF ) t + cos(2ω _IF ) t. Since the cos(2ω _IF ) t of the output signal RF2 is lower in frequency than cos(2ω _LO + ω _IF ) t + cos(2ω _LO - ω _IF ) t, it will be ignored.

Furthermore, output signal RF3 is sin(ω _LO +ω _IF )t - sin(ω _LO -ω _IF )t, and output signal RF4 is sin(2ω _LO +ω _IF )t - sin(2ω _LO -ω _IF )t + sin(2ω _IF )t. The sin(2ω _IF )t of output signal RF4 is ignored because it has a lower frequency than sin(2ω _LO +ω _IF )t - sin(2ω _LO -ω _IF )t.

The phase shifter 270 advances the phase of the output signal RF4 output from the mixer 240 by 90 degrees, so that the output signal RF4 output from the phase shifter 270 becomes cos(2ω _LO +ω _IF )t-cos(2ω _LO -ω _IF )t.

Therefore, the output of adder 280 is 2cos( _2ωLO + _ωIF )t, which is the sum of cos(2ωLO + _ωIF )t+cos( _{2ωLO -ωIF} )t of output signal RF2 and cos( _2ωLO + _ωIF )t-cos( _{2ωLO -ωIF} )t of the output of phase shifter 270. Since the frequency obtained _from angular velocity _ωLO is 150 GHz, the frequency of the output of adder 280 is in the 300 GHz band. In other words, the frequency of output signal RF output from adder 280 is 2×LO+IF, which is in the band obtained by adding the frequency IF of the I signal and the Q signal to 300 GHz.

In embodiment 2, HPF 150 has an input terminal connected to the output terminal of adder 280 and an output terminal connected to output terminal 202. HPF 150 outputs the 300 GHz band component of the output of adder 280 as the transmit signal RF (2 x LO + IF).

Figure 6 shows the output signal RF1 from mixer 130 and the transmit signal RF output from HPF 150. In Figure 6, the horizontal axis represents frequency and the vertical axis represents signal strength. The output signal RF1 also contains a 10 GHz component of the IF signal, but this is omitted here.

As shown in Figure 6, the 150 GHz band contains the +IF and -IF bands, which are the output signal RF1 (LO ± IF) of mixer 130, and the 300 GHz band contains only the +IF band, which is the transmit signal RF (2 x LO + IF), and no -IF band. In this way, by mixing the I and Q signals with local signals of the same frequency twice in two systems using two-stage mixers 130, 230 and mixers 140, 240, a transmit signal RF in the 300 GHz band can be obtained.

As described above, by mixing four local signals of the same frequency output from the same signal source 110 in two systems for the I and Q signals using two-stage mixers 130, 140 and mixers 230, 240, it is possible to obtain output signals RF2 and RF4 in the 300 GHz band using a 150 GHz local signal. Because local signals output from the same signal source 110 and amplified by amplifiers 221, 222, 223, and 224 are supplied to mixers 130, 140, 230, and 240, respectively, the frequencies of the four local signals supplied to mixers 130, 140, 230, and 240 are exactly equal at 150 GHz. Therefore, it is possible to generate output signals RF2 and RF4 in the 300 GHz band with high precision using a 150 GHz local signal, which is below the upper limit frequency that amplifiers 221, 222, 223, and 224, realized using HEMTs, can amplify. Then, output signal RF2 and output signal RF4, whose phase has been advanced by 90 degrees to match output signal RF2 by phase shifter 270, are added by adder 280, and unnecessary frequency components are removed by HPF 150, after which the signal can be output from output terminal 202 as transmission signal RF.

Therefore, it is possible to provide a transmitting device 200 and electronic device 20 that can output a transmission signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device.

Furthermore, to obtain output signal RF2 at mixer 140, two 150 GHz local signals with completely equal frequencies are output from the same signal source 110 and amplified by amplifiers 221 and 222, respectively, and supplied to mixers 130 and 140. Similarly, to obtain output signal RF4 at mixer 240, two 150 GHz local signals with completely equal frequencies are output from the same signal source 110 and amplified by amplifiers 223 and 224, respectively, and supplied to mixers 230 and 240. This suppresses the generation of unnecessary frequency components, making it possible to obtain 300 GHz output signals RF2 and RF4 with high precision and little error.

Furthermore, the phase of the output signal RF4 output from mixer 240 is advanced by 90 degrees by phase shifter 270 to match it with output signal RF2, and then added by adder 280. This cancels out the -IF band and results in an output signal RF (2 x LO + IF) that selectively retains only the +IF band. This makes it possible to output an output signal RF (2 x LO + IF) that selectively retains only the +IF band. In other words, the frequency of the final output signal RF can be set to 2 x LO + IF.

Furthermore, extraneous frequency components contained in the output signal RF (2 x LO + IF) output from adder 280 can be removed by HPF 150 and output as the transmit signal RF from output terminal 202. The frequency of the transmit signal RF is 2 x LO + IF, which includes the +IF band but not the -IF band, so the frequency band of the transmit signal RF that is finally output can be selectively set to the +IF band at 300 GHz.

The 300 GHz band is a promising frequency band for next-generation 6G communications. However, it is difficult to realize semiconductor circuits that operate at such high frequencies as 300 GHz. Even when using transistors with high electron mobility such as HEMTs, the upper limit of signals that can be amplified with good amplification characteristics by amplifiers 221, 222, 223, and 224 is around 150 GHz.

As explained in embodiment 1, it is difficult to combine an IF signal and a 300 GHz local signal using a single mixer. Furthermore, if a multiplier is used, the bandwidth of the IF signal will be tripled or doubled (3 x IF or 2 x IF), making it impossible to obtain output signals RF2 and RF4 with frequencies of 2 x LO ± IF, as in embodiment 2 above.

From this perspective, it can be said that the transmitter 200, which outputs four 150 GHz local signals with identical frequencies from the same signal source 110, amplified by amplifiers 221, 222, 223, and 224, and supplies them to mixers 130, 140 and mixers 230, 240, achieves extremely efficient frequency conversion and amplification. Furthermore, this configuration produces highly accurate, low-error 300 GHz output signals RF2, RF4, RF, and transmit signal RF.

In addition, by including an HPF 150 provided on the output side of the adder 280, it is possible to efficiently and easily remove 150 GHz band components that may be included in the output signal RF output from the adder 280, enabling a high-quality 300 GHz band transmission signal RF to be output.

<First Modification of Second Embodiment>
7 is a diagram showing the configuration of an electronic device 20M1 including a transmission device 200M1 according to a first modified example of embodiment 2. The electronic device 20M1 includes a data output unit 50 and the transmission device 200M1. Like the electronic device 20, the electronic device 20M1 is, for example, a smartphone, a tablet computer, or another portable device having a communication function.

Transmitting device 200M1 differs from transmitting device 200 of embodiment 2 in that amplifier 260A is added between mixer 130 and mixer 140, and amplifier 260B is added between mixer 230 and mixer 240. The rest of the configuration is the same as transmitting device 200 of embodiment 2, so only the differences will be explained here.

Amplifier 260A is an example of a second amplifier, and amplifier 260B is an example of a third amplifier. Amplifier 260A has an input terminal connected to the output terminal of mixer 130 and an output terminal connected to the input terminal of mixer 140. Amplifier 260B has an input terminal connected to the output terminal of mixer 230 and an output terminal connected to the input terminal of mixer 240.

Like amplifiers 221, 222, 223, and 224, amplifiers 260A and 260B are realized, for example, by HEMTs. Amplifier 260A further amplifies output signal RF1 output from mixer 130 and outputs it to mixer 140, and amplifier 260B further amplifies output signal RF3 output from mixer 230 and outputs it to mixer 240. After being combined by mixers 140 and 240, the operation is the same as that of transmitting device 200 in embodiment 2.

Therefore, it is possible to provide a transmitting device 200M1 and electronic device 20M1 that are capable of outputting a transmit signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device. Furthermore, because transmitting device 200M1 includes amplifier 260A between mixer 130 and mixer 140, and amplifier 260B between mixer 230 and mixer 240, the output of the transmit signal RF can be further increased. The amplification factors of amplifiers 260A and 260B can be set to appropriate values depending on the application of transmitting device 200M1, etc.

<Second Modification of Second Embodiment>
8 is a diagram showing the configuration of an electronic device 20M2 including a transmission device 200M2 according to a second modification of embodiment 2. The electronic device 20M2 includes a data output unit 50 and the transmission device 200M2. Like the electronic device 20, the electronic device 20M2 is, for example, a smartphone, a tablet computer, or another portable device having a communication function.

Transmitting device 200M2 differs from transmitting device 200 of embodiment 2 in that it has a subtractor 290 instead of an adder 280. Other configurations are the same as transmitting device 200 of embodiment 2, so only the differences will be explained here.

The output of the subtractor 290 is 2cos( _2ωLO -ωIF)t, which is the difference between cos(2ωLO+ _ωIF )t+cos( _2ωLO - _ωIF )t of the output signal RF2 and cos( _{2ωLO + ωIF} )t-cos( _2ωLO - _ωIF )t of the output of the phase shifter 270. Since the frequency obtained from the angular velocity _ωLO is 150 GHz, the frequency of the output of the subtractor 290 is in the 300 GHz band. In other words, _the frequency of the output signal RF output from the subtractor 290 is 2×LO-IF, which is in the band obtained by subtracting the frequency IF of the I signal and Q signal from 300 GHz.

In the second variant of embodiment 2, the HPF 150 outputs the 300 GHz band component of the output of the subtractor 290 as the transmit signal RF (2 x LO-IF).

Figure 9 shows the output signal RF1 from mixer 130 and the transmit signal RF output from HPF 150. In Figure 9, the horizontal axis represents frequency and the vertical axis represents signal strength. The output signal RF1 also contains a 10 GHz component of the IF signal, but this is omitted here.

As shown in Figure 9, mixer 130's output signal RF1 (LO ± IF) is generated around 150 GHz, and a transmit signal RF (2 x LO - IF) is generated in a band that is lower than 300 GHz by the frequency of the IF signal. In this way, by mixing local signals of the same frequency twice for the I and Q signals in two systems using two-stage mixers 130, 230 and mixers 140, 240, a transmit signal RF in the 300 GHz band can be obtained.

Therefore, it is possible to provide a transmitting device 200M2 and electronic device 20M2 that can output a transmission signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device.

The phase of output signal RF4 output from mixer 240 is advanced by 90 degrees by phase shifter 270 to match output signal RF2, and then the difference is calculated by subtractor 290. This cancels out the +IF band and results in an output signal RF (2 x LO-IF) that selectively retains only the -IF band. This makes it possible to output an output signal RF (2 x LO-IF) that selectively retains only the -IF band. In other words, the frequency of the final output signal RF can be set to 2 x LO-IF.

Furthermore, the HPF 150 removes unnecessary frequency components contained in the output signal RF (2×LO-IF) output from the subtractor 290, and the result is output from the output terminal 202 as the transmit signal RF. The frequency of the transmit signal RF is 2×LO-F, which includes the -IF band but not the +IF band, so the frequency band of the transmit signal RF that is finally output can be selectively set to the -IF band at 300 GHz.

<Simulation results>
Fig. 10 is a diagram showing a simulation model of the transmitting device 100 of the first embodiment. The simulation model shown in Fig. 10 corresponds to the transmitting device 100 shown in Fig. 1. Fig. 10 shows the input terminal 101, the output terminal 102, the signal source 110, and the mixers 130 and 140, but omits the amplifiers 121 and 122 and the HPF 150. A 10 GHz, 10 dBm signal was input as the IF signal, and a 150 GHz, 20 dBm signal was input as the local signal.

The simulation conditions were to calculate only the +IF components (LO + IF, 2 x LO + IF), and not the -IF components (LO - IF, 2 x LO - IF). Furthermore, amplifiers 121 and 122 were omitted, and instead the local signal output was increased by the amplification factor of amplifiers 121 and 122. The conversion loss of mixers 130 and 140 was set to -20 dB.

Figure 11 shows the simulation results for the transmitter 100 of embodiment 1. When an IF signal (10 GHz, 10 dBm) and a local signal (150 GHz, 20 dBm) were input, the output signal RF1 was 160 GHz, -11.1 dBm, and the output signal RF2 was 310 GHz, -31.1 dBm. Although the output power of the output signal RF2 was low, it was confirmed that an output signal RF2 of 310 GHz was obtained.

Figure 12 is a diagram showing a simulation model of a transmission device 100M according to a modified example of the first embodiment. The simulation model shown in Figure 12 is the same as the simulation model shown in Figure 10 except that an amplifier 160 with an amplification factor (gain) of 40 dB has been added. The other simulation conditions are the same as those of the simulation model shown in Figure 10.

Figure 13 shows the simulation results for a transmission device 100M according to a modified example of embodiment 1. When an IF signal (10 GHz, 10 dBm) and a local signal (150 GHz, 20 dBm) were input, the output signal RF1 was 160 GHz and -11.1 dBm, the same as the results shown in Figure 11. The output signal RF2, which is affected by the amplification of amplifier 160, was 310 GHz and 8.85 dBm. It was confirmed that the output increased by approximately 40 dB compared to the simulation results shown in Figure 11.

As described above, it was confirmed that a transmission signal RF of 8.85 dBM (approximately 7.67 mW) can be obtained at 310 GHz (300 GHz band) using a 150 GHz local signal. It is believed that a similar transmission signal RF can also be obtained with the transmitting devices 200, 200M1, and 200M2 of embodiment 2.

<Embodiment 3>
Fig. 14 is a diagram showing an example of the configuration of an electronic device 30 including a transmitting device 300 according to the third embodiment. Fig. 15 is a diagram showing an example of the waveform of a signal obtained at each unit of the transmitting device 300. In Fig. 15, the horizontal axis represents frequency, and the vertical axis represents amplitude.

As shown in FIG. 14, the electronic device 30 includes a data output unit 50MM and a transmission device 300. Similar to the electronic device 10 of embodiment 1, the electronic device 30 is, for example, a smartphone, a tablet computer, or other portable device with communication capabilities.

In embodiment 3, the data output unit 50M has two output terminals 51A and 51B, which output an intermediate frequency IF signal and an IF bar signal, respectively. The IF bar signal is a signal whose phase is 180 degrees different from that of the IF signal, and is a signal with the phase of the IF signal inverted. The IF signal and IF bar signal are differential input signals that are generated inside the data output unit 50M and output from the output terminals 51A and 51B. The IF signal is an example of a first input signal, and the IF bar signal is an example of a second input signal.

Transmitting device 300 has input terminals 301A and 301B, output terminal 302, signal source 110, balun 310, amplifiers 321 and 322, mixers 331, 332, 333, and 334, matching circuits 340A and 340B, a connection unit 350, and an adder 360. Mixers 331, 332, 333, and 334 are provided in two stages with two systems for the IF signal and the IF bar signal.

Balun 310 is an example of a differential output section. Amplifier 321 is an example of a first amplifier. Amplifier 322 is an example of a second amplifier. Mixers 331, 332, 333, and 334 are examples of a first mixer, a second mixer, a third mixer, and a fourth mixer, respectively.

Outside the transmitting device 300, the input terminal 301A is connected to the output terminal 51A of the data output unit 50M, and an IF signal is input from the data output unit 50M. Inside the transmitting device 300, the input terminal 301A is connected to one input terminal of the mixer 331.

Outside the transmitting device 300, the input terminal 301B is connected to the output terminal 51B of the data output unit 50M, and an IF bar signal is input from the data output unit 50M. Inside the transmitting device 300, the input terminal 301B is connected to one input terminal of the mixer 332.

Output terminal 302 is connected to the output terminal of adder 360 inside transmitting device 300, and is connected to antenna 103 outside transmitting device 300. Output terminal 302 is a terminal that outputs the transmission signal RF obtained by transmitting device 300 performing frequency conversion and amplification on the IF signal and IF bar signal. Note that a circuit for performing impedance matching or other processing, for example, may be provided between output terminal 302 and antenna 103.

Signal source 110 outputs a local signal (LO). Signal source 110 is the same as signal source 110 in embodiments 1 and 2. The frequency LO of local signal LO is, for example, 150 GHz. 150 GHz is close to the upper limit of the frequency of signals that can be amplified by amplifiers 321 and 322 realized with HEMTs, but it is a frequency at which HEMTs can operate as amplifiers 321 and 322 with good amplification characteristics. The output terminal of signal source 110 is connected to unbalanced side winding 311 of balun 310 and connection part 350.

Balun 310 has an unbalanced side winding 311 and a balanced side winding 312. One end of balanced side winding 312 is connected to the input terminal of amplifier 321, and the other end is connected to the input terminal of amplifier 322. Balun 310 generates and outputs local signals +LO and -LO from local signal LO input from signal source 110. Local signal +LO has the same amplitude, frequency, and phase as local signal LO. Local signal +LO is identical to local signal LO. Local signal -LO is a signal with the phase of local signal +LO inverted, and is 180 degrees out of phase with local signal +LO. Local signals +LO and -LO form a differential signal.

The local signal +LO is a signal having a positive amplitude and can be expressed as cosω _LO ·t as shown in Fig. 15(A), and the local signal −LO is a signal having a negative amplitude and can be expressed as −cosω _LO ·t as shown in Fig. 15(B).

Amplifier 321 has an input terminal connected to one end of balanced side winding 312 and an output terminal connected to the other input terminal of mixer 331, and amplifies the local signal +LO input from balun 310 and outputs it to mixer 331. Amplifier 321 is implemented using a HEMT.

Amplifier 322 has an input terminal connected to the other end of balanced side winding 312 and an output terminal connected to the other input terminal of mixer 332, and amplifies the local signal -LO input from balun 310 and outputs it to mixer 332. Amplifier 322 is implemented using a HEMT. It is preferable to set the gain of amplifier 322 to the same value as the gain of amplifier 321, taking into account the symmetry of the circuit.

Mixer 331 has two input terminals connected to input terminal 301A and the output terminal of amplifier 321, and an output terminal connected to the input terminal of matching circuit 340A. Mixer 331 mixes the IF signal input from input terminal 301A with the local signal + LO amplified by amplifier 321, and outputs the result as output signal RF1 to matching circuit 340A. Output signal RF1 is an example of a first output signal.

As a result, the frequency of output signal RF1 is LO ± IF. Frequencies LO ± IF are a band that includes 150 GHz. Also, as shown in Figure 15 (C), the waveform of output signal RF1 is a waveform in which an IF signal with a positive amplitude and a frequency of LO ± IF exists before and after a local signal + LO with a positive amplitude at frequency LO.

Mixer 332 has two input terminals connected to input terminal 301B and the output terminal of amplifier 322, and an output terminal connected to the input terminal of matching circuit 340B. Mixer 332 mixes the IF bar signal input from input terminal 301B with the local signal -LO amplified by amplifier 322, and outputs the result as output signal RF2 to matching circuit 340B. Output signal RF2 is an example of a second output signal.

As a result, the frequency of output signal RF2 is LO ± IF. Frequencies LO ± IF are a band that includes 150 GHz. Also, as shown in Figure 15 (D), the waveform of output signal RF2 is such that an IF signal with a positive amplitude and a frequency of LO ± IF exists before and after a local signal -LO with a negative amplitude and a frequency of LO.

Matching circuit 340A has an input terminal connected to the output terminal of mixer 331 and an output terminal connected to one input terminal of mixer 333. Matching circuit 340A is an example of a first matching circuit. Matching circuit 340A is provided to achieve impedance matching between mixers 331 and 333, and allows output signal RF1 output from mixer 331 to pass through unchanged.

Matching circuit 340B has an input terminal connected to the output terminal of mixer 332 and an output terminal connected to one input terminal of mixer 334. Matching circuit 340B is an example of a second matching circuit. Matching circuit 340B is provided to achieve impedance matching between mixers 332 and 334, and allows output signal RF2 output from mixer 332 to pass through unchanged.

Mixer 333 has two input terminals connected to the output terminal of matching circuit 340A and connection unit 350, and an output terminal connected to one input terminal of adder 360. Mixer 333 mixes output signal RF1 input from matching circuit 340A with local signal LO input from connection unit 350, and outputs the result to adder 360 as output signal RF3. Output signal RF3 is an example of a third output signal.

As a result, the frequency of output signal RF3 is 2 x LO ± IF. The frequency 2 x LO ± IF is a band that includes 300 GHz. As shown in Figure 15 (E), the waveform of output signal RF3 is a waveform that has a local signal +2LO with a frequency of 2LO and a positive amplitude, and an IF signal with a frequency of 2LO ± IF and a positive amplitude.

Mixer 334 has two input terminals connected to the output terminal of matching circuit 340B and connection unit 350, and an output terminal connected to the other input terminal of adder 360. Mixer 334 mixes output signal RF2 input from matching circuit 340B with local signal LO input from connection unit 350, and outputs the result to adder 360 as output signal RF4. Output signal RF4 is an example of a fourth output signal.

As a result, the frequency of output signal RF4 is 2×LO±IF. The frequency 2×LO±IF is a band that includes 300 GHz. As shown in Figure 15 (F), the waveform of output signal RF4 has a local signal -2LO with a negative amplitude at frequency 2LO, and an IF signal with a frequency 2LO±IF with a positive amplitude.

Adder 360 has two input terminals connected to the output terminal of mixer 333 and the output terminal of mixer 334, and an output terminal connected to output terminal 302. Adder 360 adds output signal RF3 input from mixer 333 and output signal RF4 input from mixer 334.

When output signals RF3 and RF4 are added together, the result is as shown in Figure 15(G). By adding output signal RF3, which has a local signal +2LO with a frequency of 2LO and a positive amplitude, and an IF signal with a frequency of 2LO ± IF, to output signal RF4, which has a local signal -2LO with a negative amplitude at frequency 2LO and an IF signal with a frequency of 2LO ± IF and a positive amplitude, the local signals +2LO and -2LO cancel each other out, resulting in an IF signal with a frequency of 2LO ± IF and a positive amplitude. The frequency of the IF signal shown in Figure 15(G) is 300 GHz ± IF, and its amplitude is twice that of the IF signals shown in Figures 15(C) to 15(F).

Here, the angular velocity of the IF signal is ω _IF , and the angular velocity of the local signal is ω _LO . The frequency obtained at angular velocity ω _LO is 150 GHz. The local signal +LO is cosω _LO ·t, the local signal −LO is −cosω _LO ·t, the IF signal is cos(ω _IF ·t), and the IF bar signal is −cos(ω _IF ·t).

The output signal RF1 is cosω _LO ·t+cos(ω _LO +ω _IF )t+cos(ω _LO −ω _IF )t, and the output signal RF2 is −cosω _LO ·t+cos(ω _LO +ω _IF )t+cos(ω _LO −ω _IF )t.

The output signal RF3 is cos2ω _LO ·t+cos(2ω _LO +ω _IF )t+cos(2ω _LO −ω _IF )t, and the output signal RF4 is −cos2ω _LO ·t+cos(2ω _LO +ω _IF )t+cos(2ω _LO −ω _IF )t.

Therefore, the output of adder 360 becomes _2cos ( _2ωLO +ωIF)t+2cos(2ωLO _-ωIF )t, which is obtained by adding _cos2ωLO.t +cos( _2ωLO + _ωIF )t+cos( _{2ωLO -ωIF} )t of output signal RF3 and -cos2ωLO.t+cos _{( 2ωLO} + _ωIF )t+cos( _{2ωLO -ωIF} )t of output signal _RF4 . The output of adder 360 is the transmit signal RF.

Since the frequency obtained from the angular velocity ω _LO is 150 GHz, the frequency of the output of the adder 360 is in the 300 GHz band. That is, the frequency of the output signal RF output from the adder 360 is 2×LO+IF, and as shown in FIG. 15(G), an IF signal is obtained whose frequency is 300 GHz±IF and whose amplitude is twice that of the IF signal shown in FIGS. 15(C) to 15(F).

As described above, the local signals +LO and -LO obtained by the balun 310 are amplified and then mixed with the IF signal and IF bar signal to generate output signals RF1 and RF2. The local signal LO is then added to the output signals RF1 and RF2 to obtain output signals RF3 and RF4. When the output signals RF3 and RF4 are added, the local signal +2LO (cos2ω _LO ·t) contained in the output signal RF3 and the local signal -2LO (-cos2ω _LO ·t) contained in the output signal RF4 cancel each other out, resulting in an IF signal with a frequency of 2LO±IF and twice the amplitude of the original IF signal being obtained as the transmit signal RF. 2LO±IF is 300 GHz±IF.

Therefore, it is possible to provide a transmitting device 300 and electronic device 30 that can output a transmission signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device.

In addition, since the transmit signal RF does not include the local signal +2LO and the local signal -2LO, only an IF signal with a frequency of 300 GHz ±IF and an amplitude twice that of the original IF signal can be obtained.

Furthermore, as in embodiments 1 and 2, the IF signal bandwidth is doubled without using a multiplier, resulting in a highly accurate and error-free 300 GHz output signal transmission RF.

Figure 16 is a diagram showing an example of the configuration of electronic device 30M including transmission device 300M according to a modified example of embodiment 3. Figure 17 is a diagram showing an example of the waveform of a signal obtained at each section of transmission device 300M. In Figure 17, the horizontal axis represents frequency, and the vertical axis represents amplitude.

As shown in FIG. 16, electronic device 30M includes a data output unit 50MM and a transmission device 300M. Like electronic device 30, electronic device 30M is, for example, a smartphone, tablet computer, or other portable device with communication capabilities.

Transmitting device 300M has input terminals 301A and 301B, output terminal 302, signal source 110M, balun 310, amplifiers 321 and 322, mixers 331, 332, 333M, and 334M, matching circuits 340MA and 340MB, connection section 350, and adder 360. Mixers 331, 332, 333M, and 334M are arranged in two stages and two systems for the IF signal and the IF bar signal. The following explanation focuses on the differences from transmitting device 300 shown in Figure 14. Mixers 333M and 334M are examples of the third mixer and fourth mixer, respectively.

Signal source 110M differs from signal source 110 shown in FIG. 14 in that it outputs a 100 GHz local signal (LO). In the modified example of embodiment 3, the frequency LO of the local signal LO is 100 GHz. As a result, signal source 110M has more leeway than signal source 110 of embodiment 1 with respect to the upper limit of the frequency of signals that can be amplified by amplifiers 321 and 322 realized using HEMTs, allowing amplifiers 321 and 322 realized using HEMTs to operate with good amplification characteristics.

As shown in Fig. 17(A), the local signal +LO is a signal having a positive amplitude and can be expressed as cosω _LO ·t. Also, as shown in Fig. 17(B), the local signal −LO is a signal having a negative amplitude and can be expressed as −cosω _LO ·t. The frequency LO is 100 GHz.

The frequency of the output signal RF1 output by mixer 331 is LO ± IF, where the frequencies LO ± IF are in a band that includes 100 GHz. Furthermore, as shown in Figure 17 (C), the waveform of the output signal RF1 is such that an IF signal with a positive amplitude and a frequency of LO ± IF exists before and after a local signal with a positive amplitude and a frequency of LO + LO.

Similarly, the frequency of the output signal RF2 output by mixer 332 is LO ± IF, where the frequencies LO ± IF are in a band that includes 100 GHz. Also, as shown in Figure 17 (D), the waveform of the output signal RF2 is such that an IF signal with a frequency of LO ± IF and a positive amplitude exists before and after a local signal -LO with a negative amplitude at frequency LO.

Mixer 333M differs from mixer 333 shown in FIG. 14 in that it is a harmonic mixer. As a harmonic mixer, mixer 333M creates a 200 GHz signal using internal distortion components (nonlinear components) based on the local signal LO input from connection section 350, and mixes the 200 GHz signal with output signal RF1 to output output signal RF3 at 300 GHz. Output signal RF3 output by mixer 333M is an example of a third output signal.

As a result, the frequency of output signal RF3 is 3 x LO ± IF. The frequency 3 x LO ± IF is a band that includes 300 GHz. As shown in Figure 17 (E), the waveform of output signal RF3 has a local signal +3LO with a frequency of 3LO and a positive amplitude, and an IF signal with a frequency of 3LO ± IF and a positive amplitude.

Mixer 334M differs from mixer 334 shown in FIG. 14 in that it is a harmonic mixer. As a harmonic mixer, mixer 334M creates a 200 GHz signal using internal distortion components (nonlinear components) based on the local signal LO input from connection section 350, and mixes the 200 GHz signal with output signal RF2 to output output signal RF4 at 300 GHz. Output signal RF4 output by mixer 334M is an example of a fourth output signal.

As a result, the frequency of output signal RF4 is 3 x LO ± IF. The frequency 3 x LO ± IF is a band that includes 300 GHz. As shown in Figure 17 (F), the waveform of output signal RF4 has a local signal -3LO with a negative amplitude at frequency 3LO, and an IF signal with a frequency 3LO ± IF with a positive amplitude.

Adder 360 has two input terminals connected to the output terminal of mixer 333M and the output terminal of mixer 334M, and an output terminal connected to output terminal 302. Adder 360 adds output signal RF3 input from mixer 333M and output signal RF4 input from mixer 334M.

When output signals RF3 and RF4 are added together, the result is as shown in Figure 17(G). By adding output signal RF3, which has a local signal +3LO with a frequency of 3LO and a positive amplitude, and an IF signal with a frequency of 3LO ± IF, to output signal RF4, which has a local signal -3LO with a negative amplitude at frequency 3LO and an IF signal with a frequency of 3LO ± IF and a positive amplitude, the local signals +3LO and -3LO cancel each other out, resulting in an IF signal with a frequency of 3LO ± IF and a positive amplitude. The frequency of the IF signal shown in Figure 17(G) is 300 GHz ± IF, and its amplitude is twice that of the IF signals shown in Figures 17(C) to 17(F).

Here, the frequency obtained at angular velocity ω _LO is 100 GHz. The local signal +LO is cosω _LO ·t, the local signal −LO is −cosω _LO ·t, the IF signal is cos(ω _IF ·t), and the IF bar signal is −cos(ω _IF ·t).

The output signal RF1 is cosω _LO ·t+cos(ω _LO +ω _IF )t+cos(ω _LO −ω _IF )t, and the output signal RF2 is −cosω _LO ·t+cos(ω _LO +ω _IF )t+cos(ω _LO −ω _IF )t.

The output signal RF3 is cos3ω _LO ·t+cos(3ω _LO +ω _IF )t+cos(3ω _LO −ω _IF )t, and the output signal RF4 is −cos3ω _LO ·t+cos(3ω _LO +ω _IF )t+cos(3ω _LO −ω _IF )t.

Therefore, the output of the adder 360 becomes _2cos ( _3ωLO + _ωIF )t+2cos(3ωLO -ωIF)t, which is obtained by adding _cos3ωLO.t +cos( _3ωLO + _ωIF )t+cos( _{3ωLO -ωIF} )t of the output signal RF3 and -cos3ωLO.t+cos( _3ωLO + _ωIF )t+cos( _{3ωLO -ωIF} )t of the output _{signal RF4} .

Since the frequency obtained from the angular velocity ω _LO is 100 GHz, the frequency of the output of the adder 360 is in the 300 GHz band. That is, the frequency of the output signal RF output from the adder 360 is 3×LO+IF, and as shown in FIG. 17(G), an IF signal is obtained whose frequency is 300 GHz±IF and whose amplitude is twice that of the IF signal shown in FIGS. 17(C) to 17(F).

As described above, the local signals +LO and −LO obtained by the balun 310 are amplified and then mixed with the IF signal and IF bar signal to generate output signals RF1 and RF2, and the local signal LO is added to the output signals RF1 and RF2 to obtain output signals RF3 and RF4. When the output signals RF3 and RF4 are added, the local signal +3LO (cos3ω _LO ·t) included in the output signal RF3 and the local signal −3LO (−cos3ω _LO ·t) included in the output signal RF4 cancel each other out, resulting in an IF signal with a frequency of 300 GHz±IF and an amplitude twice that of the original IF signal.

Therefore, it is possible to provide a transmitting device 300M and electronic device 30M that can output a transmission signal RF in a frequency band that exceeds the upper frequency limit of the semiconductor device.

In addition, since the transmit signal RF does not include the local signal +3LO and local signal -3LO, only an IF signal with a frequency of 300 GHz ±IF and an amplitude twice that of the original IF signal can be obtained.

Furthermore, as in embodiments 1 and 2, the IF signal bandwidth is doubled without using a multiplier, resulting in a highly accurate and error-free 300 GHz output signal transmission RF.

Furthermore, compared to embodiments 1 to 3, it is possible to use a signal source 110M that outputs a local signal LO at a lower frequency. Therefore, compared to the signal source 110 of embodiment 1, the signal source 110M has a greater margin for the upper frequency limit of the signal that can be amplified by the amplifiers 321 and 322 realized using HEMTs, and the amplifiers 321 and 322 realized using HEMTs can operate with good amplification characteristics.

The above describes a transmitting device and an electronic device according to exemplary embodiments of the present disclosure. However, the present invention is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.
The following additional notes are provided regarding the above-described embodiments.
(Appendix 1)
a signal source that outputs a local signal of a first frequency;
a first amplifier that amplifies the local signal output from the signal source;
a first mixer that mixes a first input signal of an intermediate frequency with the local signal amplified by the first amplifier to output a first output signal;
a second mixer that mixes the first output signal output from the first mixer with a local signal amplified by the first amplifier and outputs a second output signal.
(Appendix 2)
The transmitting device described in Supplementary Note 1 further includes a second amplifier provided between the first mixer and the second mixer, amplifying the first output signal output from the first mixer and outputting the amplified signal to the second mixer.
(Appendix 3)
3. The transmitting device according to claim 1, further comprising a high-pass filter provided on the output side of the second mixer, the high-pass filter passing signals in a band including a second frequency that is twice the first frequency.
(Appendix 4)
a third mixer that mixes a second input signal of the intermediate frequency, which has a phase difference of 90 degrees from that of the first input signal, with the local signal amplified by the first amplifier, and outputs a third output signal;
a fourth mixer that mixes the third output signal output from the third mixer with the local signal amplified by the first amplifier to output a fourth output signal; a phase shifter that aligns the phases of the second output signal and the fourth output signal;
3. The transmitting device according to claim 1, further comprising: an adder that adds the second output signal and the fourth output signal whose phases are aligned.
(Appendix 5)
5. The transmitting device according to claim 4, further comprising a high-pass filter provided on the output side of the adder, the high-pass filter passing signals in a band including a second frequency that is twice the first frequency.
(Appendix 6)
a third mixer that mixes a second input signal of the intermediate frequency, which has a phase difference of 90 degrees from that of the first input signal, with the local signal amplified by the first amplifier, and outputs a third output signal;
a fourth mixer that mixes the third output signal output from the third mixer with the local signal amplified by the first amplifier to output a fourth output signal; a phase shifter that aligns the phases of the second output signal and the fourth output signal;
a subtractor that outputs a difference between the second output signal and the fourth output signal, the phases of which are aligned.
(Appendix 7)
7. The transmitting device according to claim 6, further comprising a high-pass filter provided on the output side of the subtractor, for passing signals in a band including a second frequency that is twice the first frequency.
(Appendix 8)
a second amplifier provided between the first mixer and the second mixer, amplifying the first output signal output from the first mixer and outputting the amplified first output signal to the second mixer;
The transmitting device according to any one of appendixes 4 to 7, further comprising a third amplifier provided between the third mixer and the fourth mixer, amplifying the third output signal output from the third mixer and outputting the amplified signal to the fourth mixer.
(Appendix 9)
The first amplifier
an amplifier provided between the signal source and the first mixer, amplifying the local signal output from the signal source and outputting the amplified local signal to the first mixer;
an amplifier provided between the signal source and the second mixer, amplifying the local signal output from the signal source and outputting the amplified signal to the second mixer.
(Appendix 10)
The first amplifier
an amplifier provided between the signal source and the first mixer, amplifying the local signal output from the signal source and outputting the amplified local signal to the first mixer;
an amplifier provided between the signal source and the second mixer, amplifying the local signal output from the signal source and outputting the amplified signal to the second mixer;
an amplifier provided between the signal source and the third mixer, amplifying the local signal output from the signal source and outputting the amplified local signal to the third mixer;
an amplifier provided between the signal source and the fourth mixer, amplifying the local signal output from the signal source and outputting the amplified signal to the fourth mixer.
(Appendix 11)
11. The transmitter of claim 10, wherein the plurality of amplifiers of the first amplifier are implemented with high electron mobility transistors.
(Appendix 12)
a signal source that outputs a local signal of a first frequency;
a differential output unit connected to an output side of the signal source and configured to output, from the local signal, a differential signal including a first local signal and a second local signal obtained by inverting the phase of the first local signal;
a first amplifier connected to an output side of the differential output unit and amplifying the first local signal;
a second amplifier connected to an output side of the differential output unit and amplifying the second local signal;
a first mixer that mixes a first input signal of an intermediate frequency with the first local signal amplified by the first amplifier to output a first output signal;
a second mixer that mixes a second input signal obtained by inverting the phase of the first input signal with the second local signal to output a second output signal;
a third mixer that mixes the first output signal output from the first mixer with the local signal to output a third output signal;
a fourth mixer that mixes the second output signal output from the second mixer with the local signal to output a fourth output signal;
an adder that adds the third output signal output from the third mixer and the fourth output signal output from the fourth mixer.
(Appendix 13)
a first matching circuit provided between the first mixer and the third mixer, the first matching circuit passing signals in the first frequency band;
13. The transmitting device according to claim 12, further comprising: a second matching circuit provided between the second mixer and the fourth mixer, the second matching circuit passing signals in the first frequency band.
(Appendix 14)
the third mixer is a harmonic mixer that mixes the first output signal output from the first mixer with the local signal to output the third output signal having a frequency three times the first frequency,
The transmitting device described in Appendix 12 or 13, wherein the fourth mixer is a harmonic mixer that mixes the second output signal output from the second mixer with the local signal and outputs the fourth output signal having a frequency three times the first frequency.
(Appendix 15)
15. The transmitter device according to any one of claims 12 to 14, wherein the first amplifier and the second amplifier are realized using high electron mobility transistors.
(Appendix 16)
16. The transmitting device according to any one of claims 1 to 15, wherein the first frequency is 150 GHz.
(Appendix 17)
a data output section that outputs the first input signal as a data signal;
10. An electronic device comprising: a transmitting device according to any one of Supplementary Notes 1 to 3 and 9.
(Appendix 18)
a data output section that outputs the first input signal and the second input signal as data signals;
An electronic device comprising: a transmitting device according to any one of Supplementary Notes 4 to 8 and 10.
(Appendix 19)
a data output section that outputs the first input signal and the second input signal as data signals;
16. An electronic device comprising: a transmitting device according to any one of appendices 12 to 15.

10, 10M Electronic device 50 Data output section 100, 100M Transmitter 101 Input terminal 102 Output terminal 110 Signal source 121, 122 Amplifier 130, 140 Mixer 150 HPF
160 Amplifier 20, 20M1, 20M2 Electronic device 200, 200M1, 200M2 Transmitter 201A, 201B Input terminal 202 Output terminal 110 Signal source 221, 222, 223, 224 Amplifier 130, 140, 230, 240 Mixer 150 HPF
260A, 260B Amplifier 270 Phase shifter 280 Adder 290 Subtractor 50, 50M Data output section 300, 300M Transmitter 110M Signal source 321, 322 Amplifier 331, 332, 333, 334 Mixer 350 Connection section 360 Adder

Claims (5)

a signal source that outputs a local signal of a first frequency;
a differential output unit connected to an output side of the signal source and configured to output, from the local signal, a differential signal including a first local signal and a second local signal obtained by inverting the phase of the first local signal;
a first amplifier connected to an output side of the differential output unit and amplifying the first local signal;
a second amplifier connected to an output side of the differential output unit and amplifying the second local signal;
a first mixer that mixes a first input signal of an intermediate frequency with the first local signal amplified by the first amplifier to output a first output signal;
a second mixer that mixes a second input signal obtained by inverting the phase of the first input signal with the second local signal to output a second output signal;
a third mixer that mixes the first output signal output from the first mixer with the local signal to output a third output signal;
a fourth mixer that mixes the second output signal output from the second mixer with the local signal to output a fourth output signal;
an adder that adds the third output signal output from the third mixer and the fourth output signal output from the fourth mixer;
a transmitting device including : a first matching circuit provided between the first mixer and the third mixer, the first matching circuit passing signals in the first frequency band;
The transmitting device according to claim 1 , further comprising: a second matching circuit provided between the second mixer and the fourth mixer, the second matching circuit passing signals in the first frequency band. the third mixer is a harmonic mixer that mixes the first output signal output from the first mixer with the local signal to output the third output signal having a frequency three times the first frequency,
3. The transmitting device according to claim 1, wherein the fourth mixer is a harmonic mixer that mixes the second output signal output from the second mixer with the local signal to output the fourth output signal having a frequency three times the first frequency. 4. The transmitter according to claim 1 , wherein the first amplifier and the second amplifier are realized by high electron mobility transistors. a data output section that outputs the first input signal and the second input signal as data signals;
An electronic device comprising: a transmitter according to claim 1 ;