JP3905542B2 - Wireless transceiver - Google Patents

Description

  The present invention relates to a radio transceiver including a local oscillation circuit unit capable of outputting a continuous wave and a modulated wave.

  A conventional wireless communication device includes an ASK modulator that ASK modulates a carrier wave using a data signal, and a QPSK modulator that QPSK modulates a carrier wave using an I signal and a Q signal, and a carrier input terminal of the ASK modulator To the output terminal of the QPSK modulator.

  In addition, a mixer for mixing the received wave and the carrier wave is connected in parallel to the ASK modulator, and between the mixer, the ASK modulator and the QPSK modulator, the ASK modulator and the QPSK modulation are used during transmission signal processing. And a switch for connecting the mixer and the QPSK modulator during reception signal processing, and the QPSK modulator outputs a sine wave as a carrier wave during reception signal processing.

Further, when outputting a QPSK modulated wave during transmission signal processing, the QPSK modulator outputs a QPSK modulated wave obtained by QPSK modulation of the carrier wave using the I signal and the Q signal, and the ASK modulator has a constant amplification factor. The modulated wave was amplified. When an ASK modulated wave is output during transmission signal processing, the QPSK modulator outputs a sine wave, and the ASK modulator performs ASK modulation of the sine wave using a data signal.
The power levels of the local oscillation signals supplied to the reception circuit unit and the transmission circuit unit were equal (for example, see Patent Document 1).

JP 2002-289898 A

  As described above, in the radio transceiver that shares the local oscillation circuit unit with the reception circuit unit and the transmission circuit unit, the local oscillation signal supplied to the reception circuit unit and the power of the local oscillation signal output supplied to the transmission circuit unit The level was equal.

  However, the power level of the local oscillation signal output at which the characteristics of the reception circuit section are good and the power level of the local oscillation signal output at which the characteristics of the transmission circuit section are good are not necessarily equal, the local oscillation circuit section and the reception circuit It is necessary to provide an amplifier and an attenuator between the local oscillation circuit unit and the transmission circuit unit, and between the reception circuit unit and the transmission circuit unit.

  In addition, when the characteristics depending on the local oscillation signal power level of the reception circuit unit and the transmission circuit unit fluctuate due to changes in temperature, it is necessary to change the power level of the local oscillation signal output by the temperature correction circuit or the like. It was.

  The present invention was made to solve the above-described problems, and by providing a modulator in the local oscillation circuit unit, it can cope with each operation state during reception signal processing and transmission signal processing, An object of the present invention is to provide a radio transmitter / receiver that can cope with a change in characteristics of a transmission / reception circuit unit due to temperature and that can control a power level of a local oscillation signal output to simplify a circuit configuration and have good transmission / reception characteristics. .

A radio transceiver according to the present invention includes an antenna that transmits and receives radio signals, a reception circuit that converts a high-frequency signal received by the antenna into an intermediate frequency signal, a transmission circuit that amplifies a signal transmitted from the antenna, a reception circuit, And a local oscillation circuit that generates a local oscillation signal necessary for each processing in the transmission circuit. The local oscillation circuit has a modulator that modulates the local oscillation signal, and generates a DC continuous wave signal during reception signal processing. generates a transmission modulation wave signal during signal processing, in a time of transmission signal processing at the time of reception signal processing, it switches the power level of the local oscillation signal output.

  A radio transceiver according to the present invention includes an antenna that transmits and receives radio signals, a reception circuit that converts a high-frequency signal received by the antenna into an intermediate frequency signal, a transmission circuit that amplifies a signal transmitted from the antenna, a reception circuit, And a local oscillation circuit that generates a local oscillation signal necessary for each processing in the transmission circuit. The local oscillation circuit has a modulator that modulates the local oscillation signal, and generates a DC continuous wave signal during reception signal processing. At the time of signal processing, a transmission modulated wave signal is generated, so it can respond to each operation state during reception signal processing and transmission signal processing, can respond to changes in characteristics of the transmission / reception circuit section due to temperature, and power of local oscillation signal output By controlling the level, the circuit configuration can be simplified and the transmission / reception characteristics can be improved.

Embodiments of a wireless transceiver according to the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a configuration diagram of an ASK-modulated radio transceiver according to Embodiment 1 of the present invention.
As shown in FIG. 1, for example, an oscillator 1 configured by a high-frequency oscillator and oscillating a fundamental frequency signal, and a control circuit unit 2 are connected to an ASK (Amplitude Shift Keying) modulator 3. In the ASK modulator 3, the output power can be controlled by controlling the fundamental frequency signal input from the oscillator 1 using the signal voltage input from the control circuit unit 2. In this way, the ASK modulator 3 can generate and output a continuous wave.
The oscillator 1 and the ASK modulator 3 constitute a local oscillation circuit unit 4 that generates a local oscillation signal necessary for each processing in the reception circuit unit 7 and the transmission circuit unit 10 described later.

  The low noise amplifier 5 and the down converter 6 constitute a receiving circuit unit 7 that converts a high frequency signal received by an antenna 12 described later into an intermediate frequency signal. The output side of the reception circuit unit 7 is connected to an IF output terminal 8 for extracting a reception signal converted to an intermediate frequency (IF) by the down converter 6.

The high-power amplifier 9 constitutes a transmission circuit unit 10 that amplifies a signal transmitted from an antenna 12 described later.
A first switch 11 is provided between the input terminal of the reception circuit unit 7, the input terminal of the transmission circuit unit 10, and the output terminal of the local oscillation circuit unit 4.
The first switch 11 switches the circuit in order to supply the local oscillation signal output from the local oscillation circuit unit 4 to either the reception circuit unit 7 or the transmission circuit unit 10.
When processing a radio signal received by the antenna 12 (during reception signal processing), the first switch 11 connects the local oscillation circuit unit 4 and the reception circuit unit 7 and processes a radio signal transmitted from the antenna 12. At times (during transmission signal processing), the contact is switched so that the local oscillation circuit unit 4 and the transmission circuit unit 10 are connected.

The antenna 12 that transmits and receives radio signals is connected to the second switch 13. The second switch 13 is a switch that switches the connection destination of the antenna 12 to either the reception circuit unit 7 or the transmission circuit unit 10.
When the second switch processes a radio signal received by the antenna 12 (during reception signal processing), the second switch connects the antenna 12 to the reception circuit unit 7 and processes a radio signal transmitted from the antenna 12 (transmission signal). At the time of processing), the antenna 12 is connected to the transmission circuit unit 10.

  In the local oscillation circuit unit 4, the output power of the fundamental frequency signal (constant amplitude continuous wave) generated by the oscillator 1 is controlled by the signal voltage output from the control circuit unit 2 in the ASK modulator 3. Is output as The ASK modulator 3 can modulate the local oscillation signal into either a continuous wave whose output level is constant or a modulated wave whose output level changes with time.

When processing the radio signal received by the antenna 12 (during reception signal processing), the fundamental frequency signal generated by the oscillator 1 by the constant voltage (DC voltage having a constant voltage value) output from the control circuit unit 2. (Continuous wave of constant amplitude) becomes a local oscillation signal which is a continuous wave controlled to an optimum output power level, and this local oscillation signal is output from the local oscillation circuit unit 4.
Here, the continuous wave controlled to the optimum output power level is composed of a signal having a continuous DC voltage (DC continuous wave) , and the larger the output, the better.

  A local oscillation signal which is a continuous wave output from the local oscillation circuit unit 4 is transmitted to the reception circuit unit 7 via the first switch 11. A reception signal received by the antenna 12 is input to the reception circuit unit 7 through the second switch 13, amplified by the low noise amplifier 5, and then input from the local oscillation circuit unit 4 in the down converter 6. The signal is converted into an intermediate frequency (IF) signal by the local oscillation signal and output from the IF output terminal 8.

  When processing the radio signal transmitted from the antenna 12 (during transmission signal processing), the pulse-shaped transmission signal voltage that changes in ON / OFF time and is output from the control circuit unit 2 is input to the ASK modulator 3. Then, the signal is modulated in the ASK modulator 3 and a transmission modulated wave is output from the ASK modulator 3 (this modulated wave becomes an output of the local oscillation circuit unit 4).

  The maximum power level of the modulated wave is set to the output power level Pout corresponding to the transmission signal voltage Pin in the characteristics shown in FIG. 3, and the modulated wave is output from the local oscillation circuit unit 4. The modulated wave output from the local oscillation circuit unit 4 is input to the transmission circuit unit 10 via the switch 11, amplified by the high output amplifier 9, and then transmitted to the antenna 12 via the switch 13. Then, it is transmitted from the antenna 12.

FIG. 2 shows the output characteristics depending on the power level of the local oscillation signal of the down converter 6, and FIG. 3 shows the input / output characteristics of the high-power amplifier 9.
As shown in FIG. 2, the output characteristics of the down converter 6 used at the time of reception signal processing are inflection points up to around the B level as the power level Plo of the local oscillation signal output from the local oscillation circuit section 4 increases. However, the reception IF output Pif of the down converter 6 is a linear region. Further, even when the power level Plo of the local oscillation signal exceeds the B level and increases to around the A level, the slope of the characteristic becomes gentle, but the reception IF output Pif of the down converter 6 tends to increase.

  On the other hand, as shown in FIG. 3, the input / output characteristics of the high-power amplifier 9 used during transmission signal processing are as follows as the power Pin of the local oscillation signal, which is the input signal of the high-power amplifier 9, increases to around the B level. Although the power Pout of the output signal of the high-power amplifier 9 changes linearly, the power Pout of the output signal is a characteristic with non-linearity when exceeding the B level.

  Here, when the radio signal received by the antenna 12 is processed (when the received signal is processed), a local oscillation signal having a constant voltage (a DC voltage having a constant voltage value) output from the local oscillation circuit unit 4 is converted to the down converter 6. 2, there is no need to consider waveform distortion in the frequency conversion to the intermediate frequency. Therefore, in the characteristics shown in FIG. 2, the frequency conversion is performed in a nonlinear region where the local oscillation signal power Plo is high (a region where Plo is higher than B). The output waveform is not adversely affected even if the operation is performed. Therefore, during reception signal processing, the reception IF output Pif output from the down converter 6 can be increased while the local oscillation signal power Plo output from the local oscillation circuit unit 4 via the switch 11 is as large as possible.

On the other hand, when a radio signal is transmitted by the antenna 12 (at the time of transmission signal processing), a sinusoidal local oscillation signal output from the local oscillation circuit unit 4 is input to the high output amplifier 9 of the transmission circuit unit 10. It is necessary to consider the distortion of the waveform of the power Pout of the output signal of the high-power amplifier 9 during amplification. Therefore, the local oscillation signal power output from the local oscillation circuit unit 4 via the switch 11 during the transmission signal processing, that is, the input signal Pin of the high-power amplifier 9 is in the linear region (Pin is equal to or less than B) shown in FIG. It is necessary to amplify.
That is, the local oscillation circuit unit 4 generates a local oscillation signal including a transmission modulation wave signal within a range in which the high frequency signal amplified by the transmission circuit unit 10 is not distorted during transmission signal processing.

As described above, in the radio transceiver according to the present invention, the power level of the continuous wave output, which is a local oscillation signal, is increased by setting a large value of the constant voltage output from the control circuit unit 2 during reception signal processing. On the other hand, during transmission signal processing, the amplitude of the transmission signal output from the control circuit unit 2 is controlled so that the modulated wave is amplified in the linear region in the input / output characteristics of the high-power amplifier.
In this case, the ASK modulator 3 modulates the output (fundamental frequency wave) of the oscillator 1 with the output (DC voltage) of the control circuit unit 2 and outputs a DC voltage, thereby forming a local part composed of a DC voltage. An oscillation signal is output from the local oscillation circuit unit 4.

  As described above, according to the wireless transceiver according to the first embodiment of the present invention, the characteristics depend on the output power level of the local oscillation signal in the reception circuit unit 7 (down converter 6) and the transmission circuit unit 10 (high power amplifier 9). When the received signal processing is different, the local oscillation signal output from the local oscillation circuit unit 4 is a DC continuous wave, and the local oscillation signal output from the local oscillation circuit unit 4 during transmission signal processing is a transmission modulation wave. In some cases, by controlling the signal input voltage value input from the control circuit unit 2 to the ASK modulator 3 so that the above-described adverse effects are not exerted on the respective output signals of the reception circuit unit 7 and the transmission circuit unit 10, A signal having an optimum power level corresponding to each operation state during reception signal processing and transmission signal processing can be supplied, and good transmission / reception characteristics can be obtained. Such operation characteristics can be realized with a simple configuration without particularly complicating the circuit configuration.

Furthermore, the characteristics depending on the output power level of the continuous wave or the modulated wave from the local oscillation circuit unit 4 of the reception circuit unit 7 (down converter 6) and the transmission circuit unit 10 (high power amplifier 9) change due to the temperature change. Even in this case, the output signal (Pif, Pout) has the same adverse effect as described above in accordance with the temperature characteristics of the reception circuit unit 7 (down converter 6) and the transmission circuit unit 10 (high output amplifier 9). If the output power level of the local oscillation circuit unit 4 is controlled so as not to occur, a good transmission / reception characteristic corresponding to a change in temperature can be obtained without complicating the circuit configuration.
In this case, the local oscillating circuit 4 corresponds to the temperature characteristic of the transmitting circuit unit 10 during transmission signal processing, and the local oscillation circuit 4 is a local part composed of a transmission modulation wave signal within a range in which the signal amplified by the transmitting circuit unit 10 is not distorted. Generate an oscillation signal.

  In addition, as described above, the signal voltage output from the control circuit unit 2 is controlled by distinguishing between the transmission signal processing and the reception signal processing, thereby controlling the power level of the local oscillation signal output by the reception circuit unit 7 and the transmission circuit. The characteristics of the unit 10 can be controlled to be favorable, and the configuration can be simplified without providing an amplifier or an attenuator between the local oscillation circuit unit 4 and the reception circuit unit 7 or the transmission circuit unit 10. In addition, good transmission / reception characteristics can be obtained.

  Further, when the characteristics depending on the local oscillation signal power level of the reception circuit unit 7 and the transmission circuit unit 10 fluctuate due to a change in temperature, the signal voltage output from the control circuit unit 2 is used for the transmission signal processing and the reception signal. By controlling separately at the time of processing, the power level of the local oscillation signal output from the local oscillation circuit unit 4 can be controlled by the signal voltage output from the control circuit unit 2, without providing a temperature correction circuit. The configuration can be simplified and good transmission / reception characteristics can be obtained.

Embodiment 2. FIG.
FIG. 4 is a configuration diagram of an ASK-modulated radio transceiver according to the second embodiment of the present invention.
4, the same or equivalent components as those of the wireless transceiver according to the first embodiment shown in FIG.

  An oscillator 14 that generates a fundamental frequency signal for converting the output of the ASK modulator 3 into a high-frequency signal is composed of, for example, a high-frequency oscillator similar to the oscillator 1, and the output of the ASK modulator 3 and the oscillator 14 The output is connected to an up-converter 15 that is a high-frequency converter that converts to a high frequency.

A band pass filter 16 is connected to the output side of the up converter 15. The band pass filter 16 is a band pass filter that removes unnecessary frequency components included in the output of the up-converter 15.
The oscillator 1, the ASK modulator 3, the second oscillator 14, the up converter 15, and the band pass filter 16 constitute a local oscillation circuit unit 17.

Next, the operation will be described.
In the local oscillation circuit unit 17 shown in FIG. 4, the output power of the continuous wave having a constant amplitude generated by the oscillator 1 is controlled by the signal voltage output from the control circuit unit 2 in the ASK modulator 3 to generate a local oscillation signal. Is output. The output of the ASK modulator 3 is converted into a local oscillation signal having a higher frequency than the local oscillation signal at the time of transmission signal processing in the first embodiment by the continuous wave of the oscillator 14 in the up-converter 15 and then to the band pass filter 16. It is input and output from the local oscillation circuit unit 17 as a local oscillation signal from which unnecessary frequency components are removed.
The high frequency local oscillation signal output from the local oscillation circuit unit 17 is amplified by the transmission circuit unit 10 and transmitted from the antenna 12 as in the case of the first embodiment.

  In this way, the modulation circuit unit (the oscillator 14 and the up-converter 15) is configured by indirect modulation and included in the local oscillation circuit unit 17, so that it can be applied to a radio transceiver having a high transmission signal frequency. Similar to the wireless transmitter / receiver of aspect 1, a wireless transmitter / receiver having good transmission / reception characteristics can be provided with a simple configuration without complicating the circuit configuration.

  In the first and second embodiments, the case where the ASK modulator 3 is used has been described. However, the same effect can be obtained even when an arbitrary modulator such as a QPSK modulator or an ASK / QPSK shared modulator is used. be able to.

It is a block diagram of the radio | wireless transmitter / receiver of ASK modulation by Embodiment 1 of this invention. It is a figure which shows the output characteristic depending on the electric power level of the local oscillation signal of the down converter. 6 is a diagram showing input / output characteristics of a high-power amplifier 9. FIG. It is a block diagram of the radio | wireless transmitter / receiver of ASK modulation by Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Oscillator 2 Control circuit part 3 ASK modulator 4 Local oscillation circuit part 5 Low noise amplifier 6 Down converter 7 Reception circuit part 8 IF output terminal 9 High output amplifier 10 Transmission circuit part 11 1 switch, 12 antenna, 13 second switch, 14 second oscillator, 15 up-converter, 16 band-pass filter, 17 local oscillation circuit section.

Claims (2)

An antenna for transmitting and receiving radio signals;
A receiving circuit for converting a high frequency signal received by the antenna into an intermediate frequency signal;
A transmission circuit for amplifying a signal transmitted from the antenna;
A local oscillation circuit that generates a local oscillation signal necessary for each processing in the reception circuit and the transmission circuit, and the local oscillation circuit includes a modulator that modulates the local oscillation signal, and a DC continuous wave during reception signal processing generates a signal, the transmission signal to generate a transmission modulated wave signal at the time of processing, in a time of the transmission signal processing and during the reception signal processing, wireless transceiver, wherein the switching the power level of the local oscillation signal output . The wireless transceiver according to claim 1, wherein the local oscillation circuit includes a high-frequency converter for converting a local oscillation signal to be output into a high-frequency signal.

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