JP2823508B2 - High frequency stage selection amplifier circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency stage selective amplifying circuit used in a microwave digital mobile radio.

[0002]

2. Description of the Related Art A personal handy phone (PHP) is being put into practical use as a digitization of a cordless telephone system. This PHP uses the 1.9 GHz band, is a time division multiple access (TDMA) transmission system, and uses time division duplex (TDMA) using carriers of the same frequency in time division for transmission and reception.
A DD (Time Division Duplex) system is employed.
The terminal device of the above digital cordless telephone system includes a master unit and a slave unit, and the slave unit is small and easy to carry.
LSI that has been reduced in weight and divided into several blocks
C (high-density integrated circuit).

FIG. 6 is a diagram showing an example of the configuration of a conventional high frequency stage selection amplifier circuit. In the figure, reference numeral 1 denotes an antenna shared for transmission and reception, 2
Is a transmission / reception switch, and 3 is a low noise amplifier. Reference numeral 4 denotes a reception-side bandpass filter (BPF).
This is a dielectric filter having a center frequency of 9 GHz. 5
Is a mixer on the reception side, and the reception output of the BPF 4 is
The output of the local oscillator 7 is mixed with the first local oscillation signal distributed by the distributor 6 to be frequency-converted and supplied to the first intermediate frequency stage.

[0004] Reference numeral 8 denotes a mixer on the transmission side, which mixes the output from the modulator and the first local oscillation signal from the distributor 6, converts the frequency, and outputs the resultant. 9 is a transmitting side BPF, and a receiving BP
The transmission frequency signal is selectively output from the output of the mixer 8 in the same manner as F and the center frequency. 10 is an excitation amplifier, and 11 is a power amplifier. The switch 2 is a control signal (not shown).
The transmission and reception are switched at a timing according to the reception slot and transmission slot of the own station allocated to each TDMA frame.

[0005] Reference numeral 20 denotes an integrated circuit.
4, transmission BPF 9 and first local oscillator 7 are integrated circuit 2
0 terminal is externally connected. 14 is an integrated circuit 2
0 is a power supply wiring for supplying a DC voltage _Vcc to the low noise amplifier 3, the reception mixer 5, the transmission mixer 8, and the excitation amplifier 11. The voltage of the battery 13 is
_Is supplied to the power supply (V _cc ) terminal 15 of the integrated circuit 20 through the terminal.

FIG. 7 is a diagram showing an example of the configuration of the AC blocker 12. As shown in FIG.
(A) is an AC blocker 12 using a PNP transistor and a resistor R, and (B) is an AC blocker 12 ′ also called a decoupling circuit using a resistor R and a capacitor C. (C) is an AC blocker 12 ″ using only the capacitor C.
It is. Each of them has a function of preventing a high-frequency current from flowing into the battery 13, and the blocking effect is largest in (A) and smallest in (C).

[0007]

The impedance in the pass band of the reception BPF 4 and the transmission BPF 9 connected to the outside of the integrated circuit 20 is about 50Ω, but the impedance outside the band (attenuation area) is high and is about several kΩ. is there. on the other hand,
The power source impedance as viewed from the circuit side, that is, the impedance of the AC blocker 12 is several Ω. Therefore,
The low-noise amplifier 3 and the receiving mixer 5 on the receiving side, and the mixer 8 and the excitation amplifier 10 on the transmitting side, to which the power supply voltage is supplied from the power supply terminal 15 of the integrated circuit 20 via the power supply wiring 14.
Are connected via a power supply impedance of a common power supply. Further, since the wiring conductor of the power supply wiring 14 of the integrated circuit 20 and the wiring conductor of the signal line are extremely close to each other, the reception BP
There is a problem that unnecessary frequency components to be attenuated in the attenuation regions of the F4 and the transmission BPF 9 leak to the output sides of the respective BPFs via the power supply path due to electrostatic coupling between the signal wiring and the power supply wiring. As a result, the performance becomes equivalent to that of the deterioration of the attenuation range characteristic of the BPF, the spurious sensitivity is reduced on the receiving side, and the transmission side becomes unnecessary radiation and does not satisfy the provisions of the Radio Law. Therefore, BPF
Has the disadvantage that the damping characteristics of the device must be set with a margin more than necessary.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and it is possible to prevent the attenuation amount of an attenuation band from being reduced via a power supply path, and to effectively reduce the attenuation characteristic of a BPF. An object of the present invention is to provide a high-frequency-stage selection amplifier circuit that can be used effectively.

[0009]

According to a first embodiment of the present invention, a high-frequency stage selective amplifying circuit includes an antenna for transmitting and receiving a radio signal of a time division duplex system in a TDMA transmission system, and transmitting and receiving signals of the antenna. A switching device for switching, a high-frequency receiving BPF, a high-frequency transmitting BPF having the same center frequency as the receiving BPF, and the externally connected receiving BPF for amplifying a received signal from the switching device A low-noise amplifier that outputs a signal from the modulator, a receiving mixer that frequency-converts the output of the externally connected receiving BPF as one input and the first local oscillation signal as the other input, and outputs a signal from the modulator. The first local oscillation signal as the other input and frequency conversion and the externally connected transmission BPF
, A transmission mixer for amplifying the output of the transmission BPF connected to the outside, and an external first
A high-density integrated circuit provided with a distributor for distributing and outputting a signal from a local oscillator to the reception mixer and the transmission mixer; and amplifying the output of the excitation amplifier to a prescribed transmission output and providing the output to the switch. A power amplifier, wherein the high-density integrated circuit includes a power supply line independently arranged to supply power to the low-noise amplifier, the reception mixer, the transmission mixer, and the excitation amplifier; And an individual power supply terminal connected to each of the power supply terminals, and power is supplied from an external battery to each of the four individual power supply terminals via an AC blocker. .

Further, in a second embodiment of the present invention, the high-density integrated circuit is provided from one power supply terminal with a common power supply line for supplying power to the reception mixer and the transmission mixer. And an external battery for supplying power to each of the three individual power supply terminals via an AC blocker.

In a third embodiment of the present invention, the high-density integrated circuit is provided from a single power supply terminal with a common power supply line for supplying power to the reception mixer and the transmission mixer. In addition, a common power supply line for supplying power to the low-noise amplifier and the excitation amplifier is provided from one power supply terminal, and two separate power supply terminals are respectively connected from an external battery via an AC block. The power supply unit is configured to supply power to the power supply.

Further, in a fourth embodiment of the present invention, the high-density integrated circuit is provided from one power supply terminal with a common power supply line for supplying power to the reception mixer and the transmission mixer. And a power supply line for supplying power from the one power supply terminal to the low-noise amplifier and the excitation amplifier via an AC blocker, and the power supply line is provided from an external battery via the AC blocker. The terminal is configured to supply power to the terminal.

In a fifth embodiment of the present invention, the high-density integrated circuit is provided from one power supply terminal with a common power supply line for supplying power to the reception mixer and the transmission mixer. And a power supply line for supplying power from the one power supply terminal to the low-noise amplifier and the excitation amplifier via an AC blocker, respectively. The power supply terminal is configured to supply power.

[0014]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. Reference numerals 1 to 11 in the figure denote the same parts as those shown in FIG. In the first embodiment, the reception BPF 4
The power supply terminals 17 and 18 for supplying power to the low-noise amplifier 3 on the input side and the reception-side mixer 5 on the output side are provided respectively, and the power supply terminal for supplying power to the transmission mixer 8 and the excitation amplifier 10 on the transmission side in the same manner. 15 and 16 are provided respectively. The power supply voltage is supplied from the battery 13 to the power supply terminals 15, 16, 17, 18 via the independent AC blockers 12. With this configuration, the circuits before and after the BPF and the circuits on the transmission side and the reception side receive independent power supply, and the common power supply impedance is eliminated, so that the characteristics of the attenuation range of the BPF do not deteriorate.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention. The second embodiment is configured such that the reception mixer 5 and the transmission mixer 8 in the first embodiment are connected by a power supply line in the integrated circuit 20 and power is supplied from a power supply terminal 15 to both. I have. Even in this configuration, since the input side circuit and the output side circuit of the BPF do not serve as a common power supply, the attenuation characteristic of the BPF does not deteriorate.

FIG. 3 is a block diagram showing a third embodiment of the present invention. In the third embodiment, the low-noise amplifier 3 on the receiving side and the excitation amplifier 10 on the transmitting side of the second embodiment are integrated into an integrated circuit 2.
It is configured to be connected by a power supply wiring within 0 and to supply power to both from a power supply terminal 16. That is, the power supply paths of the input side circuit and the output side circuit of the BPF are independent from each other.

FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention. Although the fourth embodiment has substantially the same overall circuit configuration as the third embodiment shown in FIG. 3, an AC blocker 12 of a power supply commonly supplied to the low noise amplifier 3 and the excitation amplifier 10 is integrated. This is a configuration implemented in the circuit 20. Therefore, the electrical performance is the same as that of the third embodiment shown in FIG.

FIG. 5 is a circuit diagram showing a fifth embodiment of the present invention. The fifth embodiment has a configuration in which the power supply to the low-noise amplifier 3 of the fourth embodiment is branched and independent, and two AC blockers 12 are mounted in an integrated circuit 20.

According to the above-described embodiment of the present invention, when a BPF having a center frequency of 1.9 GHz was connected and measured, an attenuation of tens of dB to 20 dB was obtained at a detuning point of about 90 MHz.

[0020]

As described above in detail, by implementing the present invention, the deterioration of the attenuation amount of the BPF attenuation region via the power supply line is reduced, the spurious sensitivity is improved, and the unnecessary transmission wave is suppressed. An extremely large effect was obtained in practical use.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the present invention.

FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention.

FIG. 5 is a circuit diagram showing a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a conventional circuit configuration.

FIG. 7 is an example diagram of an AC blocking circuit.

[Explanation of symbols]

 Reference Signs List 1 antenna 2 switch 3 low noise amplifier 4 reception BPF 5 reception mixer 6 distributor 7 first local oscillator 8 transmission mixer 9 transmission BPF 10 excitation amplifier 11 power amplifier 12 AC blocker 13 battery 14 power supply wiring 15, 16, 17, 18 Power supply terminal 20 Integrated circuit

Claims (5)

(57) [Claims] An antenna for transmitting and receiving a radio signal of a time division duplex system in a TDMA transmission system, a switch for switching transmission and reception signals of the antenna, a reception BPF in a high frequency stage, and a center equal to the reception BPF A high-frequency transmission BPF having a frequency, a low-noise amplifier that amplifies a reception signal from the switch and outputs the amplified signal to the externally connected reception BPF, and a reception BPF that is externally connected. A reception mixer that converts the output to one input and the first local oscillation signal to the other input to convert the frequency, and a signal from the modulator to one input and converts the frequency to the first local oscillation signal to the other input and is connected to the outside. A transmission mixer for outputting to the transmission BPF,
A high-density integrated circuit comprising: an excitation amplifier for amplifying an output of a transmission BPF connected to the outside; and a distributor for distributing and outputting a signal from an external first local oscillator to the reception mixer and the transmission mixer. And a power amplifier that amplifies the output of the excitation amplifier to a prescribed transmission output and supplies the output to the switch. The high-density integrated circuit includes the low-noise amplifier, the reception mixer, the transmission mixer, and the excitation A power supply line is provided independently for supplying power to the amplifier, and a separate power supply terminal connected to each of the power supply lines is provided. A high-frequency-stage selection amplifier circuit configured to supply power to individual power terminals. 2. The high-density integrated circuit has a common power supply line for supplying power to the reception mixer and the transmission mixer, and is disposed from one power supply terminal. 2. The high frequency stage selection amplifier circuit according to claim 1, wherein power is supplied to the three individual power terminals via the power supply terminal. 3. The high-density integrated circuit according to claim 1, wherein a common power supply line for supplying power to the reception mixer and the transmission mixer is provided from one power supply terminal, and the low-noise amplifier is provided. And a power supply line for supplying power to the excitation amplifier is provided in common from one power supply terminal, and power is supplied from an external battery to each of the two individual power supply terminals via an AC blocker. 2. The high-frequency stage selection amplifier circuit according to claim 1, wherein: 4. The high-density integrated circuit according to claim 1, wherein a common power supply line for supplying power to the reception mixer and the transmission mixer is provided from one power supply terminal, and the one power supply is provided. A power supply line is provided from a terminal for supplying power to the low noise amplifier and the excitation amplifier via an AC blocker, and power is supplied from an external battery to the one power supply terminal via the AC blocker. 2. The high-frequency-stage selective amplifying circuit according to claim 1, wherein: 5. The high-density integrated circuit according to claim 1, wherein a common power supply line for supplying power to the reception mixer and the transmission mixer is provided from one power supply terminal, and A power supply line for supplying power from the power supply terminal to the low-noise amplifier and the excitation amplifier via an AC blocker is provided, and power is supplied from an external battery to the one power supply terminal via the AC blocker. 2. The high-frequency stage selection amplifier circuit according to claim 1, wherein said high-frequency stage selection amplification circuit is configured to supply the signal.