JPH0666711B2 - Wireless device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wireless device capable of transmitting and receiving at the same time.

[Conventional technology]

FIG. 6 is a block diagram showing a conventional wireless device. In the figure, 1 is an antenna that receives radio waves and emits radio waves, and 2 outputs the radio waves received by these antennas to a reception end 2a and a transmission end 2b. Input the transmission signal to the above antenna 1
It is an antenna duplexer that outputs to and distributes the received signal and the transmitted signal. Reference numeral 3 is a high-frequency amplifier which receives a received signal from the receiving end 2a of the antenna duplexer 2 and amplifies it with low noise.
Is a band-pass filter that receives the amplified signal from the high-frequency amplifier 3 and selectively outputs only the reception wave frequency, and 5 receives the selected output from the band-pass filter 4 and outputs a demodulation output to the output terminal 6. The receiving section is composed of a converter, an intermediate frequency amplifier, a demodulator and the like. A modulation input such as a voice input from the input terminal 8 is input to the transmission terminal 7 and transmits a high frequency transmission signal to the transmission end 2b of the antenna duplexer 2.
And 9 is a transmission start switch for outputting a transmission start signal for activating this transmission section.

Next, the operation will be described. First, the case where only the reception is performed, that is, the case where the transmission start signal is not output from the transmission start switch 9 (OFF state) will be described. The radio wave received from the antenna 1 is received by the antenna duplexer 2 at the receiving end 2a.
Is guided to the high frequency amplifier 3 via. Then, the received signal is low-noise amplified by the high-frequency amplifier 3, then selected by the band-pass filter 4 as only the received signal, and the demodulated output is output from the receiving unit 5 to the output terminal 6.

Next, a case where reception and transmission are performed at the same time, that is, a case where a transmission activation signal is output from the transmission activation switch 9 (on state) will be described. The transmitter 7 which has received the transmission start signal from the transmission start switch 9 is in the operating state. Even in such a state, the radio wave received from the antenna 1 is output as a demodulation output to the output terminal 6 via the antenna duplexer 2, the high frequency amplifier 3, the band pass filter 4, and the receiving unit 5 as in the above. It The modulation input input to the input terminal 8 is converted into a high-frequency transmission signal by the transmitting unit 7 in the operating state, and then radiated from the antenna 1 via the antenna duplexer 2.

[Problems to be solved by the invention]

Since the conventional wireless device is configured as described above, when receiving and transmitting at the same time, a part of the transmission signal from the transmitting unit 7 spills into the high frequency amplifier 3, causing the output saturation of the high frequency amplifier 3. Since there is a risk that sensitivity will be reduced, the transmission signal must be reduced by configuring the receiving end side of the antenna duplexer 2 with a large amount of attenuation, which not only makes the antenna duplexer 2 large and expensive. There is a problem in that the high frequency amplifier 3 needs to flow a large amount of current so that the output does not saturate even during reception only during reception, resulting in an increase in power consumption.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a wireless device that can perform transmission and reception at the same time and that can be reduced in size and power consumption.

[Means for solving problems]

The wireless device according to the present invention is provided with current increasing means for operating in response to a transmission state signal and a frequency state signal and increasing the current of the high frequency amplifier when transmitting and receiving simultaneously.

[Work]

The current increasing means in this invention increases the current of the high frequency amplifier in response to the transmission state signal and the frequency state signal when transmitting and receiving at the same time, prevents the output saturation of the high frequency amplifier, and reduces the sensitivity thereof. To prevent.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, 1 is an antenna, 2 is an antenna duplexer, 3 is a high-frequency amplifier, 4 is a bandpass filter, 5 is a receiving unit, 6 is an output terminal, 7 is a transmitting unit, 8 is an input terminal, and a sixth Since these are the same as or equivalent to those of the related art denoted by the same reference numerals in the drawings, detailed description thereof will be omitted. Further, 10 is a current increasing means connected to the high frequency amplifier 3, 11 is a control section for supplying a frequency state signal 12 and a transmission state signal 13 to the current increasing means 10, and the transmission state signal 13 is transmitted at the same time as the transmitting section 7. Also sent to. FIG. 2 is a circuit diagram showing the details of the high frequency amplifier 3 and the current increasing means 10. In the figure, 31 is a high frequency amplifying transistor whose base is connected to the receiving end 2a of the antenna duplexer 2 via the capacitor 32. , The collector is connected to the input end of the bandpass filter 4 via the capacitor 33,
The emitter is grounded via an emitter resistor 34 and a capacitor 35. Further, 41 is a switching transistor which is opened / closed by the transmission state signal 13 and whose emitter is grounded. 42, 43 are switching transistors which are opened / closed by the frequency state signal 12a or 12b and whose emitter is connected to the collector of the switching transistor 41, respectively. 44 and 45 are shunt resistors connected between the collector of the switching transistor 42 or 43 and the emitter of the high frequency amplifier transistor 31.

Next, the operation will be described. First, a case where only reception is performed, that is, a case where the transmission state signal 13 is not output from the control unit 11 (off state) will be described. Since the transmission state signal 13 is not input to the base from the control unit 11, the switching transistor 41 is in the off state and the current increasing means 10 is not operating. Therefore, the radio wave received from the antenna 1 is guided to the high frequency amplifier 3 by the antenna duplexer 2 via the receiving end 2a, and is amplified by the high frequency amplifier 3 with low noise. At this time, the resistance value of the emitter resistor 34 connected to the emitter of the high frequency amplification transistor 31 in the high frequency amplifier 3 can be selected without taking the transmission state into consideration, so that the current value of the high frequency amplification transistor 31 is selected to be small. If so, low power consumption can be achieved. The reception signal amplified by this high-frequency amplifier is selected by the band-pass filter 4 only for the reception frequency, and the demodulation output is output from the receiving section 5 to the output terminal 6.

Next, when receiving and transmitting at the same time, that is, the control unit
A case where the transmission state signal is output from 11 (ON state) and the transmission unit 7 is in the operating state will be described. Control unit
Since the transmission status signal 13 from 11 is applied to its base,
The switching transistor 41 is turned on and the current increasing means 10 is turned on. At this time, the frequency state signal 12
The switching transistors 42 and 43 having a and 12b applied to their bases are turned on, and the shunt resistors 44 and 45 are connected in parallel with the emitter resistor 34 of the high frequency amplification transistor 31.
Are connected. As a result, the current flowing through the high frequency amplification transistor 31 is increased and the input / output saturation characteristic is improved. Therefore, the radio wave received from the antenna 1 is output as a demodulated output to the output terminal 6 via the antenna duplexer 2, the high frequency amplifier 3, the band pass filter 4, and the receiving unit 5 as in the case described above. The modulation input input to the input terminal 8 is converted into a high-frequency transmission signal by the transmission unit 7, and then radiated from the antenna 1 via the antenna duplexer 2.
At this time, the frequency state signals 12a and 12b from the control unit 11 are applied to the bases of the switching transistors 42 and 43 individually or both according to the frequency, whereby the switching transistors 42 and 43 are respectively applied. The transistors are turned on independently or at the same time, and the current of the high frequency amplification transistor 31 is increased according to the frequency.
Therefore, even if a part of the transmission signal from the transmission unit 7 spills into the high frequency amplifier 3, when the attenuation amount is small in the characteristic diagram of the pass filter 4 shown in FIG. 3, for example, in the frequency point 52, Frequency state signals 12a, 12 from the control unit 11
By means of b, the switching transistors 42, 43 are turned on at the same time, and a large amount of current should flow in the high frequency amplification transistor 31.

In the above embodiment, as the current increasing means, the switching transistors 42 and 43 are opened and closed by the frequency state signals 12a and 12b from the control unit 11, but as shown in FIG. It is also possible to use the frequency information signal 14 that changes according to the transmission frequency from the transmission unit 7 and use the current increasing means 15 that increases or decreases the current of the high frequency amplification transistor 31 according to the frequency information signal 14. The frequency information signal 14 may be a voltage control type frequency variable oscillator control voltage of a frequency synthesizer used in the transmitter 7, and the characteristic of the frequency information signal 14 is shown in FIG. Now, assuming that the amount of attenuation of the antenna duplexer 2 is small with respect to the frequency point 52 on the characteristic curve of FIG. 5, the frequency increases to the current increasing means 15 to which the transmission state signal 13 from the control unit 11 is applied. Supply the information signal 14,
The current of the transistor 31 for high frequency amplification is increased to improve the input / output saturation characteristic. If the amount of attenuation of the antenna duplexer 2 is sufficient for the frequency point 51 on the characteristic curve, the frequency information signal 14 is sent to the current increasing means 15.
Is supplied to reduce the current of the transistor 31 for high frequency amplification, so that low power consumption can be achieved.

Further, in the above embodiment, the case where the current increasing means receives the transmission status signal from the control section has been described, but this transmission status signal may be received from the transmission section activated by the control section, and the status indicating that the transmission is in progress. May be received from another device as long as it is a signal for surely displaying, and the same effect as that of the above-described embodiment is obtained.

〔The invention's effect〕

As described above, according to the present invention, it is configured to operate by receiving the transmission state signal and the frequency state signal and to add the current increasing means for increasing the current of the high frequency amplifier during transmission and reception to the high frequency amplifier. The current of the high-frequency amplifier is suppressed to a small value to reduce the power consumption when it is only, and the current of the high-frequency amplifier increases when it is performed at the same time as transmission and reception, and the input / output saturation characteristic is improved and its sensitivity is improved. As a result, it is possible to obtain a wireless device that is good, small, inexpensive, and consumes less power.

[Brief description of drawings]

FIG. 1 is a block diagram showing a radio apparatus according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing a main part thereof, FIG. 3 is an explanatory diagram showing an example of characteristics of a bandpass filter, and FIG. FIG. 6 is a circuit diagram showing a main part of another embodiment of the present invention, FIG. 5 is a block diagram showing an example of characteristics of a frequency information signal, and FIG. 6 is a block diagram showing a conventional radio apparatus. 2 is an antenna duplexer, 2a is a receiving end, 2b is a transmitting end, 3 is a high frequency amplifier, 7 is a transmitting unit, 10 and 15 are current increasing means, 12 and 12a,
12b is a frequency status signal, 13 is a transmission status signal, 14 is a frequency information signal (frequency status signal), 31 is a high frequency amplification transistor, 34 is an emitter resistor, 41, 42 and 43 are switching transistors, and 44 and 45 are shunts. Resistor. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A radio apparatus comprising a high-frequency amplifier for amplifying a reception signal from a reception end of an antenna duplexer and a transmission section for outputting a transmission signal to the transmission end of the antenna duplexer, and capable of transmitting and receiving at the same time. When the transmission and the reception are performed at the same time, it operates by receiving the transmission status signal indicating the status of transmission and the frequency status signal indicating the frequency status, and increases the current of the high frequency amplifier. A wireless device comprising means. 2. The high frequency amplifier comprises a high frequency amplifying transistor having a base to which the received signal is input and an emitter connected to an emitter resistor, and the current increasing means is connected to an emitter of the high frequency amplifying transistor. And a switching transistor that is opened / closed by the transmission status signal and the frequency status signal and controls the connection between the shunt resistance resistor and the emitter of the high frequency amplification transistor. The wireless device according to claim 1.