JP2016001834A - Alternative orthogonal modulator-demodulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alternative orthogonal modulator-demodulator for acquiring a response of a desired circuit to a modulation wave of an orthogonal modulation system or a QPSK system according to an alternative signal different from the modulation wave in the order of a time sequence for each phase, thus enabling the alternative orthogonal modulator-demodulator to acquire the response of the desired circuit with high accuracy and stability without complication in structure and an increase in size.SOLUTION: The alternative orthogonal modulator-demodulator includes carrier wave generating means for alternately generating two carrier waves whose phases are different from each other by π/2, and signal processing means for individually extracting components of the phases different from each other by π/2, in a synchronizing manner with the carrier wave generating means, from a row of a steady response output by a prescribed circuit according to the two carrier waves.

Description

  The present invention relates to an alternative quadrature modulator / demodulator that obtains a response of a desired circuit to a modulated wave in response to an alternative signal different from a quadrature modulation or QPSK modulated wave in order of time series for each phase.

  In digital communication, when transmitting a complex signal, signals of an I (In-phase) channel and a Q (Quadrature-phase) channel are modulated by an orthogonal modulator and transmitted. Upon reception, the quadrature demodulator performs quadrature demodulation of the I channel and Q channel signals, and the demodulated I channel and Q channel signals are AD (Analog-To-Digital) converted and output. Yes. Further, in a radar device, a device is proposed in which a phase shift is performed on a transmission signal in order to remove a DC (Direct Current) offset, and a reverse phase shift is performed on the reception side (patent). Reference 1).

International Publication No. 2013/024583

  As described above, when transmitting a complex signal by digital communication, a quadrature modulator or a quadrature demodulator is required. However, when an orthogonal demodulator is used, a DC offset and an orthogonal error occur.

  In the technique described in Patent Document 1, the transmission signal subjected to phase shift is orthogonally modulated and transmitted, and the received signal is orthogonally demodulated, AD-converted, and then subjected to reverse phase shift to obtain a DC offset. And canceling the orthogonal error. However, the one described in Patent Document 1 requires a quadrature demodulator with a large circuit scale, and two AD converters, one for each demodulated IQ signal. become.

  An object of the present invention is to provide an alternative quadrature modulator / demodulator which can obtain a desired circuit response accurately and stably without increasing the complexity and scale of the configuration.

In the alternative quadrature modulator / demodulator according to claim 1, the carrier wave generating means alternately generates two carrier waves having phases different from each other by π / 2. The signal processing means individually extracts the components having the phase different by π / 2 in synchronization with the carrier wave generating means from a steady response sequence output by a predetermined circuit according to the two carrier waves.
That is, a steady response to two carrier waves whose phases are different from each other by π / 2 is obtained at the output of a predetermined circuit, and these responses are alternately subjected to desired processing for each phase.

In the alternative quadrature modulator / demodulator according to claim 2, the phase variable means alternately sets the phase of the steady response output from the predetermined circuit to two values different from each other by π / 2 according to the carrier wave. The signal processing means individually extracts the components having the phase different by π / 2 in synchronization with the phase varying means from the response sequence in which the phase of the response is set by the phase varying means.
That is, a response of a predetermined circuit to the modulated wave can be obtained even though the orthogonal modulated or QPSK modulated wave is not input.

In the alternative quadrature modulator / demodulator according to the third aspect, the carrier wave generating means cyclically generates a plurality of p (≧ 3) carriers whose phases are different by (2π / p). The signal processing means individually extracts components having different phases by (2π / p) in synchronization with the carrier wave generating means from a response sequence output by a predetermined circuit in response to the plurality of p carrier waves.
That is, a steady response to a carrier wave whose phase is different by (2π / p) in order of time series is obtained from the output of a predetermined circuit, and these responses are subjected to desired processing for each phase.

5. The alternative quadrature modulator / demodulator according to claim 4, wherein the phase varying means recycles the phase of the response output from the predetermined circuit in accordance with the carrier wave into a plurality of p (≧ 3) values that differ by (2π / p). Set to. The signal processing means individually extracts components having different phases by (2π / p) in synchronization with the phase varying means from a response sequence in which the response phase is set by the phase varying means.
That is, a response of a predetermined circuit to the modulated wave can be obtained even though the orthogonal modulated or QPSK modulated wave is not input.

The alternative quadrature modulator / demodulator according to claim 5 is the alternative orthogonal modulator / demodulator according to claim 3, wherein the carrier wave generation means maintains the phase jump width of the plurality of p carriers at (2π / p).
That is, the phase jump that can be caused by the response input to the system that performs the above-described processing is maintained at a constant value (= (360 / p)).
The alternative quadrature modem according to claim 6 is the alternative quadrature modem according to claim 4, wherein the phase varying means sets a phase jump width set in a response output from the predetermined circuit to (2π / p).
That is, the phase jump that can be caused by the response input to the system that performs the above-described processing is maintained at a constant value (= (360 / p)).

The alternative quadrature modulator / demodulator according to claim 7 is the alternative orthogonal modulator / demodulator according to claim 3, wherein the carrier wave generation means randomly sets the jump width of the phase of the plurality of p carriers.
That is, since the phase jump that can be caused by the response input to the system that performs the above-described processing changes randomly, the frequency spectrum of the response is spread widely on the frequency axis.

9. The alternative quadrature modulator / demodulator according to claim 8, wherein the phase varying means randomly sets a phase jump width set in a response output from the predetermined circuit. To do.
That is, since the phase jump that can be caused by the response input to the system that performs the above-described processing changes randomly, the frequency spectrum of the response is spread widely on the frequency axis.

  According to the present invention, both of the deviation of orthogonality that can accompany quadrature modulation and QPSK modulation and the deviation of the DC offset of the circuit corresponding to each phase are reduced, and the response of the desired circuit according to the modulation wave The accuracy of the processing to be performed on is stably increased.

1 is a schematic diagram of a SAW device according to a first embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 1st Embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 2nd Embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 3rd Embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 4th Embodiment. It is a figure explaining the reason for which an orthogonal demodulation part is unnecessary. It is a block diagram used for description of DC offset and orthogonal error. It is explanatory drawing of DC offset and orthogonal error. It is explanatory drawing of DC offset and orthogonal error. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 5th Embodiment. It is a wave form diagram which shows the operation | movement of the phase shift part and transmission interest timing part in 5th Embodiment. It is explanatory drawing of the phase selection in 5th Embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 6th Embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 7th Embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 8th Embodiment. It is explanatory drawing of the switching of the phase shift in the transmission / reception apparatus which concerns on 8th Embodiment. It is a schematic diagram of a reflective SAW device according to a ninth embodiment. It is a block diagram which shows schematic structure of the transmission / reception apparatus which concerns on 9th Embodiment. It is a figure explaining the timing in the case of phase-shifting two phases with respect to a signal on the transmission side or the reception side. It is a figure explaining the timing in the case of a 4-phase phase shift with respect to a signal on the transmission side. It is a figure explaining the timing in the case of a 4-phase phase shift with respect to a signal on the receiving side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The transmission / reception apparatus according to the present invention supplies or receives a signal to a sensor device using a change in phase or amplitude. In the embodiment described below, a SAW (Surface Acoustic Wave) device will be described as an example of a sensor device. However, the sensor device is not limited to this, and changes in phase and amplitude are used. Anything is acceptable.

<First Embodiment>
FIG. 1 is a schematic diagram of a SAW device 111 according to this embodiment. FIG. 1A is a schematic top view of the SAW device 111, and FIG. 1B is a schematic cross-sectional view of the SAW device 111 as seen from the cut surface C. FIG.
The SAW device 111 includes a piezoelectric element substrate 10, a transmission electrode 11-1a, a transmission electrode 11-1b, a reception electrode 11-2a, a reception electrode 11-2b, a reaction region thin film 12, a sealing structure 14-1, and a sealing structure. 14-2.
The piezoelectric element substrate 10 is a substrate that propagates SAW. The piezoelectric element substrate 10 is a quartz substrate.

The transmission electrode 11-1a and the transmission electrode 11-1b are metal electrodes formed by a comb-like pattern constituting the transmission-side electrode unit. Hereinafter, the transmission electrode 11-1a and the transmission electrode 11-1b are collectively referred to as IDT 11-1.
In addition, the reception electrode 11-2a and the reception electrode 11-2b are metal electrodes formed by a comb-like pattern constituting the reception-side electrode unit. Hereinafter, the reception electrode 11-2a and the reception electrode 11-2b are collectively referred to as IDT 11-2.
IDT 11-1 and IDT 11-2 (collectively referred to as IDT 11) are electrodes configured on the piezoelectric element substrate 10. The IDT 11 is a pair of electrodes facing each other. The IDT 11 is made of, for example, an aluminum thin film.

The reaction region thin film 12 is a thin film formed by vapor deposition of gold. The reaction region thin film 12 is a thin film having an antibody supported on the surface. The reaction region thin film 12 is formed on the piezoelectric element substrate 10 and in a region between the pair of IDTs 11 provided to face the piezoelectric element substrate 10.
A portion where the piezoelectric element substrate 10 and the reaction region thin film 12 overlap becomes a detection region (region serving as a sensor surface) into which a liquid as a specimen is introduced.

In the SAW device 111, the dropped solution wets a specific region of the reaction region thin film 12.
The antigen in the solution reacts with the antibody carried on the reaction region thin film 12 to generate an antigen-antibody conjugate in a specific region on the reaction region thin film 12.
That is, in the reaction region thin film 12, an antigen-antibody reaction occurs between the antibody carried on the reaction region thin film 12 and the antigen in the liquid sample by dropping a liquid sample containing the antigen on the surface thereof. As a result, on the reaction region thin film 12, an antigen-antibody combined product in which the antibody carried on the reaction region thin film 12 and the antigen are combined is generated. The reaction region thin film 12 may be any material other than gold as long as it can support the antibody.

The transmission electrode unit side sealing structure 14-1 includes a sealing wall 15-1 and a sealing ceiling 16-1. In addition, although the contact bonding layer for adhere | attaching both is provided between the sealing wall 15-1 and the sealing ceiling 16-1, it is abbreviate | omitting in FIG.
The sealing wall 15-1 is a wall that covers the IDT 11-1 and is formed in a rectangular shape on the piezoelectric element substrate 10. The sealing wall 15-1 is made of, for example, a photosensitive resin.
Moreover, the sealing ceiling 16-1 is a ceiling for closing the upper side of the sealing wall 15-1 and sealing the IDT 11-1 from the outside. The sealing ceiling 16-1 is disposed on the upper side of the sealing wall 15-1 so that the sealing wall 15-1 is accommodated in the planar area of the sealing ceiling 16-1. The sealed ceiling 16-1 is made of, for example, a glass substrate. An adhesive layer (not shown) is provided between the sealing wall 15-1 and the sealing ceiling 16-1, and the space between the sealing wall 15-1 and the sealing ceiling 16-1 is sealed. Glue.
The sealing structure 14-1 is a sealing structure that covers the IDT 11-1 from the outside so as to form a space on the IDT 11-1 and prevents the IDT 11-1 from coming into contact with the liquid.

Similarly to the sealing structure 14-1, the sealing structure 14-2 on the reception electrode unit side includes a sealing wall 15-2 and a sealing ceiling 16-2, and seals the IDT 11-2 from the outside. The sealing structure covers the IDT 11-2 so as to form a space and prevents the IDT 11-2 from coming into contact with the liquid.
Even if there is a change in the atmosphere (for example, humidity) in the detection region, the IDT 11-1 and the IDT 11-2 are less affected by the sealing structure 14-1 and the sealing structure 14-2.

FIG. 2 is a block diagram illustrating a schematic configuration of the transmission / reception apparatus according to the present embodiment.
As shown in FIG. 2, the transmission / reception apparatus 100 according to the present embodiment includes a control signal generation unit 101, a phase shift unit 102, a transmission power amplification unit 103, a reception power amplification unit 104, a reception frequency conversion unit 105, an LPF (low pass filter). ) Unit 106, an AD (Analog-To-Digital; analog signal-digital signal) conversion unit 107, an I / Q separation unit 108, a delay adjustment unit 153, and a sensor unit 110.

The control signal generator 101 generates a timing signal every predetermined time. The timing signal from the control signal generation unit 101 is supplied to the phase shift unit 102 and also supplied to the I / Q separation unit 108 via the delay adjustment unit 153. The predetermined time will be described later.
The delay adjustment unit 153 delays the timing signal input from the control signal generation unit 101 by a predetermined time corresponding to the delay time of the reception signal with respect to the transmission signal, and the delayed timing signal is an I / Q separation unit. 108.

  The phase shift unit 102 and the transmission power amplification unit 103 constitute a transmission unit 151. The phase shift unit 102 performs phase shift on the input signal based on the timing signal from the control signal generation unit 101. In this embodiment, the phase shift unit 102 performs a phase shift of 0, π / 2 (rad) on the input signal based on the timing signal from the control signal generation unit 101, and thus a two-phase signal having different phases. A time-division signal consisting of That is, the phase shift unit 102 generates a time division signal by alternately generating two carrier waves having phases different from each other by π / 2. The transmission power amplifier 103 amplifies the signal from the phase shift unit 102 and supplies the amplified signal to the sensor unit 110.

  The sensor unit 110 has a SAW device 111. The sensor unit 110 detects a phase change due to the dropping of the solution of the SAW device 111 and detects the type of the solution and the components in the solution.

  The reception power amplification unit 104, the reception frequency conversion unit 105, the LPF unit 106, the AD conversion unit 107, and the I / Q separation unit 108 constitute a reception unit 152.

  The reception power amplification unit 104 receives a signal from the transmission unit 151 via the SAW device 111 and amplifies the reception signal. The reception frequency converter 105 multiplies the reception signal and the local signal to perform frequency conversion. In the present embodiment, a signal having the same frequency and phase synchronization as the input signal is used as the local signal. The input signal supplied to the phase shift unit 102 may be used as a local signal as it is. The LPF unit 106 extracts only a low frequency component from the output signal of the reception frequency conversion unit 105. The AD conversion unit 107 converts the output signal of the LPF unit 106 from an analog signal to a digital signal. The I / Q separator 108 distributes the signal from the AD converter 107 according to the timing signal from the control signal generator 101, and generates an I channel and Q channel complex signal.

  As described above, in the present embodiment, the phase shift unit 102 generates a time division signal composed of two-phase signals having different phases with respect to the input signal.

Here, assuming that the input signal s _t (t) is s _t (t) = cos (ω _c t), the transmitted time-division signal is expressed as the following equation (1).

  In the formula (1) and other formulas, square brackets [] are indices indicating phases. The time division signal represented by the equation (1) is output from the transmission power amplification unit 103 and received by the reception power amplification unit 104 via the SAW device 111. Here, in the SAW device 111, a phase change occurs due to solution dropping. If this phase change is φ and the change in amplitude is ignored, the received signal of the received power amplification section 104 is expressed by the following equation (2).

The reception frequency conversion unit 105 performs frequency conversion by multiplying each received signal by the local signal. Here, a signal having the same frequency and phase synchronization as the input signal is used as the local signal. The local signal may be a signal obtained by branching the input signal. A signal obtained by multiplying each received signal by the local signal s _loc (t) = cos (ω _c t) is a signal having a frequency of the sum of the received signal and the local signal, and the difference between the received signal and the local signal. It is a signal of the frequency. Since the received signal and the local signal are signals having the same frequency and phase-synchronized, the output signal of the received frequency converter 105 is expressed as the following equation (3), and the frequency component twice the input signal and the base It becomes a band signal (zero IF signal).

The LPF unit 106 extracts a baseband signal from the signal obtained by multiplying each received signal represented by Equation (3) by the local signal by the received frequency converting unit 105. In the formula _{(3), s c [0} ] first term cos (2ω _c t + ψ) of t because the frequency is high, are removed by the LPF section 106, _{likewise, s c [1]} The first term of t sin ( 2ω _c t + ψ) has a high frequency and is removed by the LPF unit 106. Therefore, the output of the LPF unit 106 is only two items in each equation, and becomes a time-division signal of a two-phase signal as in the following equation (4).

  The output signal of the LPF unit 106 is converted from an analog signal to a digital signal by the AD conversion unit 107. Then, the I / Q separation unit 108 is based on the timing signal input from the control signal generation unit 101 via the delay adjustment unit 153, and at the same timing as the time division of the input signal, By distributing the output signals, components having phases different by π / 2 are individually extracted and output. As a result, a complex signal of 0 phase I channel and π / 2 phase Q channel is obtained as in the following equation (5).

  As shown in Expression (5), the complex signal obtained from the I / Q separation unit 108 becomes a detection signal of a phase change due to solution dropping by the SAW device 111 of the sensor unit 110. Thus, according to the present embodiment, it is possible to generate an I channel and Q channel complex signal by equivalently realizing an orthogonal demodulation operation without using an orthogonal demodulator.

As described above, in the present embodiment, the transmission / reception apparatus 100 according to the present embodiment sequentially transmits signals having phases different from each other by π / 2 (rad) in time division. Then, the received signals are distributed at the time of reception, and an orthogonal demodulation operation is equivalently realized to generate I channel and Q channel complex signals.
With this configuration, in this embodiment, it is not necessary to use a quadrature demodulator as the reception frequency converter 105, and the circuit scale can be reduced. In addition, two AD conversion units for the I channel and the Q channel are not required, and a single AD conversion unit 107 can process and convert the received signal. In addition, unlike the Low-IF method, the AD converter 107 only needs to convert a baseband signal having a low frequency, and therefore a low-speed AD converter 107 can be used. In this embodiment, the orthogonal error is determined by the accuracy of the phase shift. For this reason, if it is the orthogonal error range calculated | required with respect to the transmitter / receiver 100, there may be tolerance in phase shift amount (pi) / 2 (rad).

Second Embodiment
Next, this embodiment will be described. FIG. 3 is a block diagram illustrating a schematic configuration of the transmission / reception device 200 according to the present embodiment. As shown in FIG. 3, the transmission / reception device 200 according to the present embodiment includes a control signal generation unit 201, a transmission power amplification unit 203, a reception power amplification unit 204, a reception frequency conversion unit 205, an LPF unit 206, an AD conversion unit 207, An I / Q separation unit 208 and a phase shift unit 209 are provided.

The control signal generator 201 generates a timing signal every predetermined time. The timing signal from the control signal generation unit 101 is supplied to the phase shift unit 209 and also to the I / Q separation unit 208. The predetermined time will be described later.
The transmission power amplification unit 203 constitutes a transmission unit 251. The reception power amplification unit 204, the reception frequency conversion unit 205, the LPF unit 206, the AD conversion unit 207, the I / Q separation unit 208, and the phase shift unit 209 constitute a reception unit 252.
The sensor unit 210 has a SAW device 211. The configuration of the SAW device 211 may be the same as that of the SAW device 111.

In this embodiment, the control signal generation unit 201, the transmission power amplification unit 203, the reception power amplification unit 204, the reception frequency conversion unit 205, the LPF unit 206, the AD conversion unit 207, and the I / Q separation unit 208 are the same as those described above. In the embodiment, the control signal generation unit 101, the transmission power amplification unit 103, the reception power amplification unit 104, the reception frequency conversion unit 105, the LPF unit 106, the AD conversion unit 107, and the I / Q separation unit 108 are configured.
The phase shift unit 209 performs a phase shift on the input signal based on the timing signal from the control signal generation unit 201. In this embodiment, the phase shift unit 209 performs a phase shift of 0, π / 2 (rad) on the input signal based on the timing signal from the control signal generation unit 201, so that two phases having different phases can be obtained. The signals are set alternately to generate a time division signal.

  In the first embodiment, the phase shift unit 102 performs phase shift of 0, π / 2 (rad) on the input signal during transmission, and transmits two-phase signals having different phases in a time division manner. . On the other hand, in this embodiment, the time-division signal is supplied as a local signal used in the reception frequency conversion unit 205. In this case as well, as in the first embodiment, the signals are separated by the I / Q separation unit 208 at the same timing as when the phase shift is performed, so that the signals are equivalently orthogonal without using a quadrature demodulator. Demodulating operation is realized, and a complex signal of 0 phase I channel and π / 2 phase Q channel can be obtained. For example, the I / Q separation unit 208 is synchronized with the phase shift timing of the phase shift unit 209 from the response sequence after the response phase is set by the phase shift unit 209 and converted by the reception frequency conversion unit 205. Then, by extracting components having phases different from each other by π / 2, complex signals of 0-phase I channel and π / 2-phase Q channel are obtained. Note that there may be a tolerance in the phase shift amount π / 2 (rad) within the orthogonal error range required for the transmission / reception device 200.

  According to the present embodiment, since the transmission signal is not phase-shifted, the spectrum width of the transmission signal does not increase compared to the transmission signal of the first embodiment. As a result, according to the present embodiment, the SAW device 211 can use a narrow band device compared to the SAW device 111 of the first embodiment. Further, according to the present embodiment, the local signal is phase-shifted on the receiving side at the timing described later, so that the delay adjustment unit 153 that is necessary in the transmission / reception device 100 is not necessary.

<Third Embodiment>
Next, this embodiment will be described. FIG. 4 is a block diagram illustrating a schematic configuration of the transmission / reception device 300 according to the present embodiment. As shown in FIG. 4, the transmission / reception apparatus 300 according to the present embodiment includes a control signal generation unit 301, a phase shift unit 302, a transmission power amplification unit 303, a reception power amplification unit 304, a reception frequency conversion unit 305, an LPF unit 306, An AD conversion unit 307, a phase reverse shift unit 308, a correlation unit 309, a delay adjustment unit 353, and a sensor unit 310 are provided.

The control signal generator 301 generates a timing signal every predetermined time. The timing signal from the control signal generation unit 301 is supplied to the phase shift unit 302 and is also supplied to the phase reverse shift unit 308 and the correlation unit 309 via the delay adjustment unit 353. The predetermined time will be described later.
The delay adjustment unit 353 delays the timing signal input from the control signal generation unit 301 by a predetermined time corresponding to the delay time of the reception signal with respect to the transmission signal, and the delayed timing signal is the phase reverse shift unit 308. And supplied to the correlation unit 309.

  The phase shift unit 302 and the transmission power amplification unit 303 constitute a transmission unit 351. The phase shift unit 302 performs phase shift on the input signal in a time division manner based on the timing signal from the control signal generation unit 301. In this embodiment, the phase shift unit 302 performs a phase shift of 0, π / 2, π, 3π / 2 (rad) on the input signal based on the timing signal from the control signal generation unit 301, A time-division signal is generated by cyclically generating four-phase signals having different phases. The transmission power amplification unit 303 amplifies the signal from the phase shift unit 302 and supplies the amplified signal to the sensor unit 310.

  The sensor unit 310 includes a SAW device 311. The sensor unit 310 detects a phase change caused by dropping the solution of the SAW device 311 to detect the type of the solution and the components in the solution. Note that the configuration of the SAW device 311 may be the same as that of the SAW device 111.

  The reception power amplification unit 304, the reception frequency conversion unit 305, the LPF unit 306, the AD conversion unit 307, the phase reverse shift unit 308, and the correlation unit 309 constitute a reception unit 352.

  The reception power amplification unit 304 receives a signal via the SAW device 311 and amplifies the reception signal. The reception frequency conversion unit 305 performs frequency conversion by multiplying each reception signal by the local signal. Here, a signal having the same frequency and phase synchronization as the input signal is used as the local signal. The input signal supplied to the phase shift unit 302 may be used as a local signal as it is. The LPF unit 306 extracts a low frequency component of the output signal of the reception frequency conversion unit 305. The AD conversion unit 307 converts the output of the LPF unit 306 from an analog signal to a digital signal. The phase reverse shift unit 308 performs a phase shift opposite to that of the phase shift unit 302 on the transmission side. The correlation unit 309 generates I-channel and Q-channel complex signals by performing correlation calculation. The correlation calculation will be described later.

  As described above, in the present embodiment, the phase shift unit 302 generates a time division signal composed of four-phase signals having different phases with respect to the input signal.

Here, assuming that the input signal s _t (t) is s _t (t) = cos (ω _c t), the transmitted time-division signal is expressed as in the following equation (6).

  The four-phase signal represented by Expression (6) is output from the transmission power amplification unit 303 in a time division manner. A signal from the transmission power amplification unit 303 is received by the reception power amplification unit 304 via the SAW device 311. In the SAW device 311, a phase change occurs due to solution dropping. If this phase change is φ and the change in amplitude is ignored, the received signal of the received power amplifying unit 304 is a time-division signal of a four-phase signal of the following equation (7).

  The reception frequency conversion unit 305 performs frequency conversion by multiplying each reception signal by the local signal. Here, as the local signal, a signal having the same frequency and phase synchronization as the received signal is used. In this case, the output signal of the reception frequency conversion unit 305 is a frequency component that is twice the input signal and a baseband signal (zero IF signal).

  The LPF unit 306 extracts a baseband signal from the signal obtained by the reception frequency conversion unit 305 multiplying each received signal by the local signal. Therefore, the output of the LPF unit 306 is a time-division signal of a four-phase signal as in the following equation (8).

  The output signal of the LPF unit 306 is converted from an analog signal to a digital signal by the AD conversion unit 307. Then, the phase reverse shift unit 308 and the correlation unit 309 perform a phase shift opposite to the phase shift of the phase shift unit 302 by performing an operation as shown in the following equation (9), and complex I channels and Q channels. Get the signal.

  In the present embodiment, the example in which the phase shift unit 302 and the phase reverse shift unit 308 shift the phase to four phases (2π is divided into four equal parts) has been described, but the phase shift may be three or more phases. Five or more phases may be used. In this case, the phase shift unit 302 phase-shifts 2π into n phases (n is 3 or more) and the phase reverse shift unit 308 converts n into n phases (n is 3 or more). Reverse phase shift. Further, when the phase shift unit 302 sets the n phase obtained by dividing 2π into n equal parts (n is 3 or more) as the phase jump width, the jump width may not always be constant, for example, set at random. May be. In this case, the phase reverse shift unit 308 performs a reverse phase shift according to the jump width corresponding to the phase jump width set by the phase shift unit 302.

As described above, in this embodiment, a signal that is phase-shifted to n phases (2π is divided into n equal parts (n is 3 or more)) is sequentially transmitted, and the phase of the signal received on the receiving side is inversely shifted after frequency conversion. . In this embodiment, by performing a correlation operation on the receiving side, it is possible to generate an I-channel and Q-channel complex signal by equivalently realizing an orthogonal demodulation operation without using an orthogonal demodulator.
With this configuration, according to the present embodiment, it is not necessary to use a quadrature demodulator, and the circuit scale can be reduced. In addition, two AD conversion units for the I channel and the Q channel are not required, and a single AD conversion unit 307 can process and convert the received signal. Further, unlike the Low-IF method, the AD conversion unit 307 only needs to convert a baseband signal having a low frequency, and therefore, a low-speed AD conversion unit 307 can be used. Note that there may be a tolerance in the amount of phase shift depending on the accuracy required for the transmission / reception device 300.

In the present embodiment, the DC offset in the reception frequency conversion unit 305 can be canceled. Further, the quadrature error is determined by the accuracy of the phase shift and the phase reverse shift, and does not occur in principle in the reception frequency conversion unit 305. These reasons will be described later.
Further, when the phase shift described with reference to FIG. 4 is four phases, a multiplier having a large circuit scale is not necessary for the phase reverse shift unit 308, and the phase reverse shift calculation by the phase reverse shift unit 308 and the correlation calculation by the correlation unit 309 are performed. And the circuit scale can be further reduced.

<Fourth embodiment>
Next, this embodiment will be described. FIG. 5 is a block diagram illustrating a schematic configuration of the transmission / reception device 400 according to the present embodiment. As shown in FIG. 5, the transmission / reception apparatus 400 according to the present embodiment includes a control signal generation unit 401, a transmission power amplification unit 403, a reception power amplification unit 404, a reception frequency conversion unit 405, an LPF unit 406, an AD conversion unit 407, A phase reverse shift unit 408, a correlation unit 409, a sensor unit 410, and a phase shift unit 412 are provided.

  The transmission power amplification unit 403 constitutes a transmission unit 451. The reception power amplification unit 404, the reception frequency conversion unit 405, the LPF unit 406, the AD conversion unit 407, the phase reverse shift unit 408, the correlation unit 409, and the phase shift unit 412 constitute a reception unit 452. The sensor unit 410 has a SAW device 411. Note that the configuration of the SAW device 411 may be the same as that of the SAW device 111.

  The control signal generation unit 401, the transmission power amplification unit 403, the reception power amplification unit 404, the reception frequency conversion unit 405, the LPF unit 406, the AD conversion unit 407, the phase reverse shift unit 408, and the correlation unit 409 are the same as those described in the third embodiment. The same configuration as the control signal generation unit 301, transmission power amplification unit 303, reception power amplification unit 304, reception frequency conversion unit 305, LPF unit 306, AD conversion unit 307, phase reverse shift unit 308, and correlation unit 309 in FIG. .

  The control signal generator 401 generates a timing signal every predetermined time. The timing signal from the control signal generation unit 401 is supplied to the phase shift unit 412 and also to the phase reverse shift unit 408 and the correlation unit 409. The predetermined time will be described later.

In the third embodiment, the phase shift unit 302 performs phase shift of 0, π / 2, π, 3π / 2 (rad) on the input signal during transmission, and has a phase difference of π / 2. A time division signal of the phase signal is generated. In contrast, in the present embodiment, the phase shift unit 412 supplies the time-divided signal as a local signal used by the reception frequency conversion unit 405. Therefore, the phase shift unit 412 cyclically sets the phase of the response output from the reception frequency conversion unit 405 according to the carrier wave to four values that differ by π / 2 degrees. This phase shift may be three or more phases, and may be five or more phases. In this case, the phase shift unit 412 shifts the phase to an n phase obtained by dividing 2π into n equal parts (n is 3 or more). Further, when the phase shift unit 302 sets the n phase obtained by dividing 2π into n equal parts (n is 3 or more) as the phase jump width, the jump width may not always be constant, for example, set at random. May be.
Also in this case, similarly to the third embodiment, the signal is separated by the phase reverse shift unit 408 and the correlation unit 409, and the quadrature demodulation operation is equivalently realized without using the quadrature demodulator. Thus, a 0-phase I-channel signal and a π / 2-phase Q-channel signal can be obtained. Here, the correlator 409 individually extracts components having different phases by π / 2 in synchronization with the phase shift timing of the phase shift unit 412 from the response sequence output from the reception frequency converter 405. Here, when the phase shift unit 412 randomly sets the phase jump width, the phase reverse shift unit 408 performs reverse phase shift according to the jump width corresponding to the jump width. Note that there may be a tolerance in the amount of phase shift within the orthogonal error range required for the transmission / reception device 400.

  According to the present embodiment, since the transmission signal is not phase-shifted, the spectrum width of the transmission signal is not widened compared to the transmission signal of the third embodiment. As a result, according to the present embodiment, the SAW device 411 can use a narrow band device compared to the SAW device 311 of the third embodiment. Also, according to the present embodiment, the local signal is phase-shifted on the receiving side at the timing described later, so that the delay adjustment unit 353 required in the transmission / reception device 300 is not necessary.

<Description of why the quadrature demodulator is unnecessary>
In the third embodiment described above, a phase shift of 0, π / 2, π, 3π / 2 is performed on the input signal to generate a time-division signal of a four-phase signal having a phase difference of π / 2. During reception, I-channel and Q-channel complex signals can be obtained by addition / subtraction without using a quadrature demodulator in the reception frequency converter. In the third embodiment, the DC offset can be canceled by such calculation. Further, the quadrature error is determined by the accuracy of the phase shift and the phase reverse shift, and does not occur in principle in the reception frequency conversion unit 305. Also in the fourth embodiment, processing similar to that in the third embodiment can be performed by performing phase shifts of 0, π / 2, π, and 3π / 2 on the local signal.

  FIG. 6 is a diagram for explaining the reason why the quadrature demodulation unit is unnecessary. In the third embodiment, it has been described that a quadrature demodulator is not used as the reception frequency conversion unit 305. On the other hand, here, in order to explain the DC offset and the quadrature error, a quadrature demodulator is used as the frequency converter.

  Since the quadrature demodulator 315 is used as the reception frequency converting unit 305, an I-channel signal and a Q-channel signal are obtained from the output of the quadrature demodulator 315. Therefore, two LPF units 306a and 306b and two AD conversion units 307a and 307b are provided. Other configurations are the same as those in the third embodiment.

  FIG. 7 shows a portion of the quadrature demodulator 315. As shown in FIG. 7, the quadrature demodulator 315 includes two multipliers 321a and 321b. In FIG. 7, Δα and Δβ are gain errors of the I channel and Q channel, Δθ is a phase error, and ΔVi and ΔVq are DC offsets of the I channel and the Q channel. Note that AD converters 307a and 307b are connected to the subsequent stage of the LPFs 306a and 306b shown in FIG.

Assuming that the n-phase received RF signal is cos (ω _t + 2nπ / N + ψ), the output signal of the mixer is expressed by the following equation (10).

In equation (10), Δα and Δβ are gain errors, ψ is a phase rotation by sensing, Δθ is a phase error, and ΔVi and ΔVq are DC offsets.
When transformed into the form of addition by the addition theorem, the expression (10) is expressed as the following expression (11).

  Next, when the second harmonic component term is removed by the LPF units 306a and 306b, the following expression (12) is obtained.

  When these signals are taken in by the AD conversion units 307a and 307b, and the phase reverse shift calculation and correlation processing are performed, they are expressed as the following equation (13).

  The expression (13) is expressed as the following expression (14) because the terms of ΔVi and ΔVq which are DC offsets are 0 when N is 2 or more.

  When equation (14) is transformed into an additive form by the addition theorem, it is expressed as the following equation (15).

  In Expression (15), when N is 3 or more, the term including 4nπ / N is 0, and therefore, it is expressed as the following Expression (16).

Although the phase rotation component remains, but the same level is mixed in the i component and q component, the constellation (signal space diagram) is a perfect circle, no image component is generated, and ideal orthogonality with no orthogonal error Functions as a demodulator.
Here, in order to make the phase rotation after compensation a little easier to understand, the equations are arranged under a special condition of Δα = Δβ = 0. The signal after the addition can be summarized as the following equation (17).

This indicates that although phase rotation occurs, the constellation is a perfect circle and no image component is generated. However, a level reduction cos (Δθ / 2) is involved as compensation. In the limit condition of Δθ = ± π, the signal level becomes zero and no longer functions as a quadrature demodulator.
By the way, the limit state of the amplitude error is when the gain of one system is zero. For example, when Δβ = −1, the signal after the addition is represented by the following equation (18).

From this, it can be seen that even if the gain of one system is 0, it functions as an ideal quadrature demodulator. The fact that the gain of one system is 0 means that the system is unnecessary. That is, as shown in FIG. 4, the reception frequency conversion unit 305 can be configured without using a quadrature demodulator.
As described above, according to the present invention, it is possible to cancel the DC offset and the quadrature error of the reception frequency converting unit 305 without using the quadrature demodulator, and the amplitude error limit state can be achieved even in only one system. Ideal quadrature demodulation is possible.
Based on this thinking, the present inventors have come to an invention that a quadrature demodulation function can be realized with a simple mixer and one ADC by using an n-phase signal. However, since the signal level is ½, the S / N is 3 dB lower than a general configuration using a quadrature demodulator and two ADCs.

  When N = 4, the rotation operator used for the phase reverse shift is a simple vector as shown in the following equation (19), so that a multiplier with a large circuit scale is not required.

  FIG. 8 shows the I-band and Q-channel baseband signals of each phase obtained in the same procedure.

  As shown in FIG. 6, the I-channel and Q-channel baseband signals extracted from the LPF units 306a and 306b are converted into digital signals by the AD conversion units 307a and 307b, and transmitted by the phase inverse shift unit 308. Is phase shifted in reverse.

  When a phase reverse shift is applied to the baseband signal of each phase I channel and Q channel as shown in FIG. 8, a signal as shown in FIG. 9 is obtained.

  It can be seen from FIG. 9 that the DC offsets ΔVi and ΔVq are canceled when the four-phase signals after the phase shift are added.

<Fifth Embodiment>
FIG. 10 is a block diagram illustrating a configuration of the transmission / reception apparatus according to the present embodiment. As illustrated in FIG. 10, the transmission / reception device 500 according to the present embodiment includes a control signal generation unit 501, a phase shift unit 502, a transmission retiming unit 521, a transmission power amplification unit 503, a reception power amplification unit 504, and a reception frequency conversion unit. 505, an LPF unit 506, an AD conversion unit 507, a phase reverse shift unit 508, a correlation unit 509, a sensor unit 510, an inverter 535, an isolation buffer 536, and a delay adjustment unit 553.

The control signal generator 501 generates a timing signal every predetermined time. A timing signal from the control signal generation unit 501 is supplied to the phase shift unit 502 and also supplied to the phase reverse shift unit 508 and the correlation unit 509 via the delay adjustment unit 553. The predetermined time will be described later.
The delay adjustment unit 553 delays the timing signal input from the control signal generation unit 501 by a predetermined time according to the delay time of the reception signal with respect to the transmission signal, and the delayed timing signal is the phase reverse shift unit 508. And supplied to the correlation unit 509.

The phase shift unit 502, the transmission retiming unit 521, and the transmission power amplification unit 503 constitute a transmission unit 551. The phase shift unit 502 includes a frequency divider 531 and a selector 532. The phase shift unit 502 performs phase shift of 0, π / 2, π, 3π / 2 (rad) based on the timing signal from the control signal generation unit 501, and a time-division signal of four-phase signals having different phases. Is generated. The transmission retiming unit 521 retimates the signal from the phase shift unit 502 with the input signal so that the four-phase signals are aligned. The transmission power amplification unit 503 amplifies the signal from the phase shift unit 502 and supplies the amplified signal to the sensor unit 510. The signal used for retiming may be an external signal synchronized with the input signal. The configuration of the SAW device 511 may be the same as that of the SAW device 111.
Also in this embodiment, the phase shift may be three or more phases, and may be five or more phases. In this case, the phase shift unit 502 performs phase shift to n phase obtained by dividing 2π by n (n is 3 or more), and the phase reverse shift unit 508 obtains n phase by dividing 2π by n (n is 3 or more). Reverse phase shift.

  The reception power amplification unit 504, the reception frequency conversion unit 505, the LPF unit 506, the AD conversion unit 507, the phase reverse shift unit 508, and the correlation unit 509 constitute a reception unit 552.

  The reception power amplification unit 504 receives a signal via the SAW device 511 and amplifies this reception signal. The reception frequency conversion unit 505 performs frequency conversion by multiplying each received signal by the local signal. Here, any output of the frequency divider 531 is used as the local signal. That is, in this example, a four-phase signal is output from the frequency dividing unit 531 constituting the phase shift unit 502, and any one of the four-phase signals is converted to a reception frequency as a local signal via the isolation buffer 536. Supplied to the unit 505. The signal from the frequency dividing unit 531 constituting the phase shift unit 502 has the same frequency as the frequency of the received signal. Note that the isolation buffer 536 prevents the accuracy from being deteriorated by mixing other signals with the local signal. In order to improve isolation, a frequency divider may be provided separately. Further, the local signal supplied to the reception frequency converting unit 505 may be a signal divided by the frequency dividing unit 531 described above, or may be a signal from the outside. In addition, the phase of the local signal may not be 0 phase, and the local signal output from the phase shift unit 502 (hereinafter also referred to as a received local signal) may be phase shifted.

The output signal of the reception frequency conversion unit 505 is input to the AD conversion unit 507 via the LPF unit.
The AD conversion unit 507 converts the output signal input from the LPF unit 506 from an analog signal to a digital signal. The phase reverse shift unit 508 performs a phase shift opposite to that of the phase shift unit 502 on the transmission side. The correlation unit 509 generates a complex signal of I channel and Q channel by performing correlation calculation.
In the present embodiment, the phase shift may be three phases or more, and may be five phases or more. In this case, the phase shift unit 502 performs phase shift to n phase obtained by dividing 2π by n (n is 3 or more), and the phase reverse shift unit 508 obtains n phase by dividing 2π by n (n is 3 or more). Reverse phase shift.

The phase shift unit 502 is supplied with a signal four times the transmission / reception frequency as an input signal. The frequency dividing unit 531 of the phase shift unit 502 is configured by a counter, for example. The input signal is frequency-divided by ¼ by the frequency divider 531, and a 4-phase signal having a phase difference of (π / 2) is output from the frequency divider 531. That is, assuming that the input signal is s _i (t) = cos (4ω _c t), the frequency dividing unit 531 outputs a four-phase signal represented by the following equation (20).

  The selection unit 532 selects one signal from the four-phase signals ps <b> 0 to ps <b> 3 from the frequency division unit 531 based on a timing control signal described later, and outputs the selected signal to the transmission retiming unit 521.

  The transmission retiming unit 521 includes an edge trigger type flip-flop 522 such as a D flip-flop or a JK flip-flop. An input signal is supplied to the transmission retiming unit 521 via the inverter 535. The signal from the selection unit 532 is retimed by the transmission retiming unit 521 so that the change point is aligned with the falling edge of the input signal.

  FIG. 11 is a waveform diagram showing operations of the phase shift unit 502 and the transmission retiming unit 521 in the present embodiment.

  An input signal as shown in FIG. 11F is supplied to the frequency divider 531. This input signal is divided by a quarter by the frequency divider 531, and as shown in FIGS. 11 (A) to 11 (D), the input signal from the frequency divider 531 has a four-phase phase difference of π / 2. Signals ps0 to ps3 are output. Here, as shown in FIGS. 11A to 11D, the signal from the frequency divider 531 includes a phase fluctuation component due to gate delay, variations in the number of gate stages, and the like. The selector 532 selects one signal from these four-phase signals ps0 to ps3. Here, it is assumed that the signal ps3 (FIG. 11D) is selected. This signal is retimed at the falling edge of the input signal shown in FIG. Thereby, as shown in FIG. 11E, the signal psn sent to the transmission power amplifier 503 is aligned with the falling edge of the input signal. Note that since the signal ps3 shown in FIG. 11D is retimed at the falling edge of the input signal, the signal psn sent to the transmission power amplifier 503 is delayed by 0.5 clock from the signal p3. Similarly, when a signal of another phase is selected, the signal psn sent to the transmission power amplifying unit 503 is aligned with the falling edge of the input signal.

  Here, as shown in FIG. 12, the selection unit 532 may select a four-phase signal by forward rotation, inversion, alternating, random, or the like. Forward rotation advances the π / 2 phase in order. Inversion advances the π / 2 phase sequentially in the inversion direction. The alternation repeats normal rotation and inversion in units of four phases. Random changes the phase randomly under the condition that the appearance probability of each phase is constant within the unit of correlation processing. In the alternating box, the time-varying influence of the four-phase signal can be canceled. At random, the spectrum spreads and the spurious response can be reduced.

  As described above, the transmission / reception device 500 according to the present embodiment receives the transmission signal and the transmission signal 551 that transmit the transmission signal divided into four phases obtained by dividing 2π into four equal parts, and receives a signal based on the transmission signal as a reception signal. Reception that obtains a complex signal by frequency-converting the received signal using a signal based on the four-phase input signal obtained by dividing 2π into four equal parts, and reversely shifting the phase of the frequency-converted signal. 552, and the transmission unit includes a frequency shift unit 531 that divides the input signal and a phase shift unit 502 that includes a selection unit 532 that selects a signal having a different phase from the output signal of the frequency division unit. And a retiming unit 521 for retiming the signal output from the selection unit 532 at the timing of the input signal.

  In this embodiment, the phase shift unit 502 and the selection unit 532 have all the edges of the n-phase (n is an integer of 3 or more) signals that are time-division multiplexed, and the phase shift accuracy that is the main cause of the quadrature error is improved. Can be improved. Further, since the signal selected by the selection unit 532 is retimed by the transmission retiming unit 521, the transmission retiming unit 521 has the jitter component of the input signal and the accuracy of the phase shift that is the main factor of the quadrature error. It can be reduced to a range of random variation of the flip-flop. Thus, by performing retiming, the accuracy of phase shift can be further improved.

  The configuration in which the phase shift unit 502 described in the present embodiment includes the frequency dividing unit 531 and the selection unit 532 can be applied to the first to fourth embodiments. For example, when the phase shift unit 102 in FIG. 2 includes a frequency division unit and a selection unit, the frequency division unit may divide by 4, and the selection unit may select 0 phase and π / 2 phase. Further, a transmission signal retiming unit may be provided, and the transmission signal retiming unit may retime the signal output from the selection unit.

<Sixth Embodiment>
Next, this embodiment will be described. FIG. 13 is a block diagram illustrating a schematic configuration of a transmission / reception device 600 according to the present embodiment. As shown in FIG. 13, the transmission / reception device 600 according to the present embodiment includes a control signal generation unit 601, a phase shift unit 602, a transmission power amplification unit 603, a reception power amplification unit 604, a reception frequency conversion unit 605, an LPF unit 606, An AD conversion unit 607, a phase reverse shift unit 608, a correlation unit 609, a sensor unit 610, and a reception retiming unit 621 are provided.

  The control signal generator 601 generates a timing signal every predetermined time. The timing signal from the control signal generation unit 601 is supplied to the phase shift unit 602 and is also supplied to the phase reverse shift unit 608 and the correlation unit 609. The predetermined time will be described later.

The transmission power amplification unit 603 constitutes a transmission unit 651. Reception power amplification section 604, reception frequency conversion section 605, LPF section 606, AD conversion section 607, phase reverse shift section 608, correlation section 609, phase shift section 602, and reception retiming section 621 constitute reception section 652. Yes. The sensor unit 610 has a SAW device 611. The configuration of the SAW device 611 may be the same as that of the SAW device 111.
In the present embodiment, the phase shift may be three phases or more, and may be five phases or more. In this case, the phase shift unit 602 phase-shifts 2π into n phases obtained by dividing n by n (n is 3 or more), and the phase reverse shift unit 608 obtains n phases obtained by dividing 2π by n (n is 3 or more). Reverse phase shift.

  The frequency division unit 631 divides the input signal, and one of the four-phase signals ps0 to ps4 from the frequency division unit 631 is selected by the selection unit 632 and output to the reception retiming unit 621. Then, the reception retiming unit 621 retimates the signal from the phase shift unit 602 with the input signal so that the edges are aligned, and sends the retimed signal to the reception frequency conversion unit 605 as a local signal. . Thereby, since the frequency conversion is performed using the retimed signal, all the edges of the signals of the respective phase-multiplexed signals are all aligned, and the phase accuracy can be improved.

  That is, the phase shift unit 602 is supplied with a signal four times the transmission / reception frequency as an input signal. This input signal is divided by ¼ by the frequency division unit 631 of the phase shift unit 602, and the frequency division unit 631 outputs a 4-phase signal having a phase difference of (π / 2). One of these four-phase signals is sent to the transmission power amplifier 603.

  In the fifth embodiment described above, the phase shift unit 502 performs phase shift of 0, π / 2, π, 3π / 2 (rad) at the time of transmission, and has four phases having a phase difference of π / 2. A divided signal is generated, re-timed by the transmission retiming unit 521, and transmitted. On the other hand, in this embodiment, the phase shift unit 602 generates a four-phase time-division signal having a phase difference of π / 2, and the reception retiming unit 621 performs retiming to generate a local signal. It is sent to the reception frequency conversion unit 605. About another structure, it is the same as that of the above-mentioned 5th Embodiment.

  With this configuration, according to the present embodiment, since the transmission signal is not phase-shifted, the spectrum width of the transmission signal does not increase compared to the transmission signal of the fifth embodiment. As a result, according to the present embodiment, the SAW device 611 can use a narrow band device compared to the SAW device 511 of the fifth embodiment. Further, according to the present embodiment, since the local signal is phase-shifted on the receiving side, the delay adjustment unit 553 that is necessary in the transmission / reception device 500 is not necessary.

<Seventh embodiment>
Next, this embodiment will be described. FIG. 14 is a block diagram illustrating a schematic configuration of a transmission / reception device 700 according to the present embodiment. As shown in FIG. 14, the transmission / reception apparatus 700 according to the present embodiment includes a control signal generation unit 701, a phase shift unit 702, a transmission retiming unit 721, a transmission power amplification unit 703, a reception power amplification unit 704, and a reception frequency conversion unit. 705, LPF units 706a and 706b, AD conversion units 707a and 707b, a phase reverse shift unit 708, a correlation unit 709, a delay adjustment unit 753, and a sensor unit 710.

The control signal generator 701 generates a timing signal for every predetermined time. The timing signal from the control signal generation unit 701 is supplied to the phase shift unit 702 and also supplied to the phase reverse shift unit 708 and the correlation unit 709 via the delay adjustment unit 753. The predetermined time will be described later.
The delay adjustment unit 753 delays the timing signal input from the control signal generation unit 701 by a predetermined time corresponding to the delay time of the reception signal with respect to the transmission signal, and the delayed timing signal is the phase reverse shift unit 708. And supplied to the correlation unit 709.

The phase shift unit 702, the transmission retiming unit 721, and the transmission power amplification unit 703 constitute a transmission unit 751. The phase shift unit 702 includes a frequency divider 731 and a selector 732. The reception power amplification unit 704, the reception frequency conversion unit 705, the LPF units 706 a and 706 b, the AD conversion units 707 a and 707 b, the phase reverse shift unit 708, and the correlation unit 709 constitute a reception unit 752. The sensor unit 710 has a SAW device 711. The configuration of the SAW device 711 may be the same as that of the SAW device 111.
The phase shift unit 702 supplies one of the four-phase signals to the reception frequency conversion unit 705 as a local signal.
Also in this embodiment, the phase shift may be three or more phases, and may be five or more phases. In this case, the phase shift unit 702 performs phase shift to n phase obtained by dividing 2π into n equal parts (n is 3 or more), and the phase reverse shift unit 708 obtains n phase obtained by equally dividing 2π into n parts (n is 3 or more). Reverse phase shift.

  Further, the local signal supplied to the reception frequency converting unit 705 may be a signal divided by the frequency dividing unit 731 described above, or may be a signal from the outside. Further, the phase of the local signal may not be 0 phase, and the received local signal output from the phase shift unit 702 may be phase shifted.

  In the present embodiment, an orthogonal demodulator is used as the reception frequency conversion unit 705. Therefore, the reception frequency converter 705 demodulates the I channel signal and the Q channel signal. The I channel and Q channel signals demodulated by the reception frequency converter 705 are converted from analog signals to digital signals by the AD converters 707 a and 707 b and supplied to the phase reverse shift unit 708. In the phase reverse shift unit 708, an operation as shown in FIG. 15 is performed. Correlation section 709 generates I-channel and Q-channel complex signals by the calculation shown in the following equation (21). Note that the four-phase signal output from the frequency divider 731 is the same as in equation (6).

  As can be seen from the equation (21), in this embodiment, the complex signals of the I channel and the Q channel are obtained as 2 cos (φ) and 2 sin (φ), respectively. The complex signals of the I channel and Q channel when the orthogonal frequency demodulation unit is not used for the reception frequency conversion unit are as shown in Equation (6). Since the signal level can be doubled as can be seen by comparing Expression (6) and Expression (19), the S / N ratio of each of the I-channel and Q-channel complex signals is improved by 3 dB according to the configuration of this embodiment. Can be made. About another structure, it is the same as that of the above-mentioned 5th Embodiment.

<Eighth Embodiment>
Next, this embodiment will be described. FIG. 15 is a block diagram illustrating a schematic configuration of a transmission / reception device 800 according to the present embodiment. As shown in FIG. 15, the transmission / reception apparatus 800 according to this embodiment includes a control signal generation unit 801, a phase shift unit 802, a transmission retiming unit 821, a transmission frequency conversion unit 841, a DA (Digital-To-Analog; digital signal). -Analog signal) conversion units 842a and 842b, transmission power amplification unit 803, reception power amplification unit 804, reception frequency conversion unit 805, LPF unit 806, AD conversion unit 807, phase reverse shift unit 808, correlation unit 809, delay adjustment unit 853 and a sensor unit 810.

The control signal generator 801 generates a timing signal for every predetermined time. The timing signal from the control signal generation unit 801 is supplied to the phase shift unit 802 and is also supplied to the phase reverse shift unit 808 and the correlation unit 809 via the delay adjustment unit 853. The predetermined time will be described later.
The delay adjustment unit 853 delays the timing signal input from the control signal generation unit 801 by a predetermined time corresponding to the delay time of the reception signal with respect to the transmission signal, and the delayed timing signal is the phase reverse shift unit 808. And supplied to the correlation unit 809.

  The phase shift unit 802, the transmission retiming unit 821, the transmission frequency conversion unit 841, the DA conversion units 842 a and 842 b, and the transmission power amplification unit 803 constitute a transmission unit 851. The reception power amplification unit 804, the reception frequency conversion unit 805, the AD conversion unit 807, the phase reverse shift unit 808, and the correlation unit 809 constitute a reception unit 852. The sensor unit 810 has a SAW device 811. The configuration of the SAW device 811 may be the same as that of the SAW device 111.

The phase shift unit 802 is supplied with a signal four times the transmission / reception frequency as a local signal as an input signal. The phase shift unit 802 includes a frequency dividing unit 831 and a switching unit 832. The frequency division unit 831 divides this input signal by ¼, and the frequency division unit 831 outputs a 4-phase signal having a phase difference of (π / 2). The switching unit 832 switches the output of the frequency dividing unit 831 in each phase. In addition, the phase shift unit 802 supplies any of the four-phase signals to the reception frequency conversion unit 805 as a signal based on the local signal.
Also in this embodiment, the phase shift may be three or more phases, and may be five or more phases. In this case, the phase shift unit 802 shifts the phase to 2 phase n divided into n (n is 3 or more), and the phase reverse shift unit 808 converts 2π into n phase (n is 3 or more) to n phase. Reverse phase shift.

  The transmission retiming unit 821 includes four edge trigger type flip-flops 822a to 822d. The transmission retiming unit 821 retimes the signal from the phase shift unit 802 with a local signal. From the transmission retiming unit 821, it is switched and output as shown in FIG. 16 for each of the 0 phase, π / 2 phase, π phase, and 3π / 2 phase, and is supplied to the transmission frequency converting unit 841. FIG. 16 is an explanatory diagram of phase shift switching in the transmission / reception apparatus according to the embodiment.

The input signals of the I channel and the Q channel are converted from digital signals to analog signals by the DA conversion units 842a and 842b, and then supplied to the transmission frequency conversion unit 841.
The transmission frequency converter 841 is composed of a quadrature modulator. By the transmission frequency conversion unit 841, the input signals of the I channel and the Q channel are orthogonally modulated using the signal from the transmission retiming unit 821 as a carrier. The signal from the transmission frequency conversion unit 841 is power amplified by the transmission power amplification unit 803 and then supplied to the sensor unit 810.

  The sensor unit 810 has a SAW device 811. The sensor unit 810 detects a phase change caused by dropping of the solution of the SAW device 811 to detect the type of solution and components in the solution.

  The signal passed through the SAW device 811 is amplified by the reception power amplification unit 804 and then supplied to the reception frequency conversion unit 805. The reception frequency conversion unit 805 is supplied with one signal in the frequency division unit 831 as a local signal.

The reception frequency conversion unit 805 performs frequency conversion by multiplying each reception signal by a local signal. The output signal of the reception frequency conversion unit 805 is converted from an analog signal into a digital signal by the AD conversion unit 807 and then supplied to the phase reverse shift unit 808.
Further, the local signal supplied to the reception frequency converting unit 805 may be a signal divided by the frequency dividing unit 831 described above or may be a signal from the outside. Further, the phase of the local signal may not be 0 phase, and the received local signal output from the phase shift unit 802 may be phase shifted.

The phase reverse shift unit 808 performs phase shift opposite to the phase shift in the phase shift unit 802. The output of the phase reverse shift unit 808 is supplied to the correlation unit 809. The correlation calculation is performed by the correlation unit 809 to cancel the DC offset of the reception frequency conversion unit 805, and the quadrature error is determined by the accuracy of phase shift and phase reverse shift, and the reception frequency conversion unit 805 generates in principle. do not do.
In the eighth embodiment, since the transmission retiming unit 821 has a flip-flop for each signal, it is possible to improve the phase accuracy of the timing of the transmission signal. In the present embodiment, the transmission frequency converter 841 can modulate and transmit a signal with sharper autocorrelation characteristics, and can directly leak from the transmitter 851 to the receiver 852 without passing through the sensor unit 810. The influence of the received signal can be reduced by more advanced reception processing.

<Ninth Embodiment>
Next, this embodiment will be described.
FIG. 17 is a schematic diagram of a reflective SAW device 111A according to this embodiment. Note that the same reference numerals are used for functional units having the same functions as those of the SAW device 111 illustrated in FIG. 17A is a schematic top view of the SAW device 111A, and FIG. 17B is a schematic cross-sectional view of the SAW device 111A as viewed from the cut surface C.

The SAW device 111A includes a piezoelectric element substrate 10A, electrodes 11A-1Aa, electrodes 11A-1b, a reaction region thin film 12A, a reflector 22, a sealing structure 14-1, and a sealing structure 14-2. The electrodes 11A-1a and 11A-1b are collectively referred to as IDT 11A-1.
As shown in FIG. 17, in the SAW device 111A, one IDT is eliminated, and a reflector 22 is provided at a position facing the transmission electrode across the detection area instead. In this configuration, one IDT can be shared for transmission and reception by switching, for example, in time division.

  The lateral length of the reaction region thin film 12A is 1 of the lateral length of the reaction region thin film 12 of the transverse SAW device 111 having the transmission electrode 11-1 and the reception electrode 11-2 shown in FIG. / 2. The lateral direction is a direction from IDT 11A-1 toward reflector 22, and a direction from IDT 11-1 to IDT 11-2.

  The reflector 22-1 reflects the SAW transmitted from the IDT 11A-1. The reflector 22 is arranged at a position facing the IDT 11A-1 across the reaction region thin film 12, and has, for example, a line width that is 1/4 of one wavelength of SAW using the same electrode material as the IDT 11A-1. It has a structure in which a plurality of lines are arranged at intervals of a half wavelength. In the example shown in FIG. 17, the structure that reflects SAW is configured by using a reflector that electrically reflects using electrodes, but the reflection of SAW may be mechanical reflection. For example, it is possible to reflect surface acoustic waves from the end face of the piezoelectric element substrate 10A. That is, the method of reflecting the SAW may be other than installing a reflector.

FIG. 18 is a block diagram illustrating a schematic configuration of a transmission / reception device 900 according to the present embodiment. As shown in FIG. 18, the transmission / reception apparatus 900 according to the present embodiment includes a control signal generation unit 901, a phase shift unit 902, a transmission power amplification unit 903, a reception power amplification unit 904, a reception frequency conversion unit 905, an LPF unit 906, An AD conversion unit 907, a phase reverse shift unit 908, a correlation unit 909, a directionality selection unit 920, a delay adjustment unit 953, and a sensor unit 910 are provided. Note that the same reference numerals are used for functional units having the same functions as those of the transmission / reception device 300 described with reference to FIG. 4 in the third embodiment, and description thereof is omitted.
In the transmission / reception device 900, for example, the electrode 11A-1b is grounded, and the transmission power amplification unit 903 or the reception power amplification unit 904 is connected to the electrode 11A-1a of the SAW device 111A via the directionality selection unit 920.

  The control signal generator 901 generates a timing signal for every predetermined time. The predetermined time will be described later. The timing signal from the control signal generation unit 901 is supplied to the phase shift unit 902 and also supplied to the phase reverse shift unit 908 and the correlation unit 909 via the delay adjustment unit 953. In addition, the control signal generation unit 901 generates a switching signal for switching between transmission and reception at a predetermined time interval, and supplies the generated switching signal to the directionality selection unit 920. Note that the control signal generation unit 901 may determine a predetermined time interval according to the transmission waveform supplied to the SAW device 111A and the delay characteristics of the SAW device 111A. Then, the control signal generation unit 901 measures the time difference at which each of the received wave leakage component and the desired wave included in the signal received for at least one phase is received, and a predetermined time interval according to the measured result May be adjusted. The leak component of the received wave and the desired wave will be described later.

  The directionality selection unit 920 is, for example, a switch, the first terminal Tx is connected to the transmission power amplification unit 903, the second terminal is connected to the electrode 11 of the SAW device 111A, and the third terminal Rx is received power. The control unit is connected to the amplification unit 904 and the control terminal is connected to the control signal generation unit 901. The directionality selection unit 920 connects the SAW 111A and the transmission power amplification unit 303 or switches the connection between the SAW 111A and the reception power amplification unit 904 according to the switching signal supplied from the control signal generation unit 901. The directionality selection unit 920 performs switching so as to connect the SAW 111A and the transmission power amplification unit 903 in the first period according to the switching signal. As a result, a transmission signal is supplied from the transmission power amplifier 903 to the SAW 111A in the first period. After the end of the first period, the directionality selection unit 920 switches to connect the SAW 111A and the reception power amplification unit 904 in the second period in accordance with the switching signal. Accordingly, the reception signal is supplied from the SAW 111A to the reception power amplification unit 904 in the second period. Note that the directionality selection unit 920 may be, for example, a power distributor / combiner, a circulator, a directional coupler, and the like, and at this time, the directionality selection unit does not require a control signal.

  The delay adjustment unit 953 delays the timing signal input from the control signal generation unit 901 by a predetermined time corresponding to the delay time of the reception signal with respect to the transmission signal, and the delayed timing signal is the phase reverse shift unit 908. And supplied to the correlation unit 909.

  In the transmission / reception apparatus 900, the time division signal transmitted to the SAW device 111A is the same as that in Expression (6). And the received signal of the received power amplifying unit 904 is a time-division signal of the four-phase signal of Expression (7). Further, the output of the LPF unit 906 is a time-division signal of a four-phase signal as shown in Expression (8). Then, the phase reverse shift unit 908 and the correlation unit 909 perform a phase shift opposite to the phase shift performed in the phase shift unit 302 by performing the calculation as shown in Equation (9), and the zero-phase I channel And π / 2-phase Q-channel complex signals.

As described above, the transmission / reception apparatus 900 according to the present embodiment does not need to use a quadrature demodulator as the reception frequency conversion unit 905 as in the transmission / reception apparatus 300 described in the third embodiment, and reduces the circuit scale. Can do. In addition, it is possible to convert a received signal into a digital signal with one AD conversion unit 907 without requiring an I-channel and Q-channel AD conversion unit.
Further, in this embodiment, similarly to the transmission / reception apparatus 300 described in the third embodiment, the phase reverse shift unit 908 and the correlation unit 909 perform the complex signal including the I channel and the Q channel by addition / subtraction as shown in the equation. And a multiplier is not necessary. In this case, the DC offset in the reception frequency conversion unit 905 can be canceled. Further, the quadrature error is determined by the accuracy of the phase shift and the phase reverse shift, and is not generated in principle by the reception frequency conversion unit 905.

  In the present embodiment, the example in which the SAW device 311 is connected to the reflective SAW device 111A in the transmission / reception apparatus 300 illustrated in FIG. 4 has been described, but the present invention is not limited thereto. The SAW device 111A includes a transmission / reception device 100 (FIG. 1), a transmission / reception device 200 (FIG. 3), a transmission / reception device 400 (FIG. 5), a transmission / reception device 500 (FIG. 10), a transmission / reception device 600 (FIG. 13), and a transmission / reception device 700 (FIG. 14) Instead of the SAW device of the transmission / reception apparatus 800 (FIG. 15), the connection may be made. In this case, as described in the transmission / reception device 900, each transmission / reception device may include a directionality selection unit and a delay adjustment unit.

<Explanation of timing in case of phase shift of two phases on transmission side>
In each embodiment described above, a predetermined time for the control signal generator to generate the timing signal will be described.
First, the timing of each signal when a two-phase phase shift is performed on the transmission side will be described. FIG. 19 is a diagram for explaining the timing when a two-phase phase shift is performed on a signal on the transmission side or the reception side.
FIG. 19 (a) is a diagram for explaining the timing when the phase is shifted with respect to the signal on the transmission side. The example shown in FIG. 19A is an example of two phases (n = 2). In FIG. 19A, the horizontal axis is time. Symbol g901 indicates a control signal from the control signal generator to the phase shift unit, symbol g902 indicates a transmission signal, symbol g903 indicates a reception signal, and symbol g904 indicates a control signal for the I / Q separator.

During the period from time t101 to t103 and the period from time t105 to t107, a control signal for outputting the 0 phase to the phase shift unit is input as shown by the image of the code g901, and the 0 phase as shown by the image of the code g902. The transmission signal is transmitted.
During the period from time t103 to t105, a control signal that outputs a π / 2 phase is input to the phase shift unit as indicated by an image g901, and a π / 2 phase transmission signal is output as indicated by an image g902. Sent.

During the period from time t102 to time t104 and during the period from time t106 to time t108, a 0-phase received signal is received as shown by the image g903, and the 0-phase is sent to the I / Q separation unit as shown by the image g904. A control signal to be output is input.
During the period from time t104 to t106, a reception signal of π / 2 phase is received as indicated by the image of g903, and control is performed to output π / 2 phase to the I / Q separation unit as indicated by the image of code g904. A signal is input.
Note that the example shown in FIG. 19A is an example in which the phase is π, and after time t105, the control signal is repeatedly input at the same timing as time t101 to t105.

<Explanation of timing in case of phase shift of two phases on receiving side>
Next, the timing of each signal when the receiving side performs a two-phase phase shift will be described.
FIG. 19B is a diagram for explaining the timing when the phase is shifted with respect to the signal on the transmission side. The example shown in FIG. 19B is an example of two phases (n = 2). In FIG. 19B, the horizontal axis is time. Symbol g911 indicates a control signal from the control signal generator to the phase shift unit, symbol g912 indicates a received local signal, symbol g913 indicates a received signal, and symbol g914 indicates a control signal from the control signal generator to the I / Q separator. .

During the period from time t111 to t113 and the period from time t113 to t114, the control signal for outputting the 0 phase to the phase shift unit is input as shown by the image of the code g911, and the 0 phase as shown by the image of the code g912. Are received from the phase shift unit to the receiving side. In addition, during this period, a 0-phase received signal is received as indicated by the image with the code g913, and a control signal for outputting the 0-phase is input to the I / Q separator as indicated by the image with the code g914.
During the period from time t112 to t113, a control signal for outputting π / 2 phase is input to the phase shift unit as indicated by an image g911, and a received local signal of π / 2 phase as indicated by an image g912. Is output from the phase shift unit to the receiving side. Also, during this period, a reception signal of π / 2 phase is received as indicated by the image of g914, and a control signal for outputting π / 2 phase to the I / Q separation unit is indicated as indicated by the image of g914. Entered.
Note that the example shown in FIG. 19B is an example in which the phase is π, and after time t113, the control signal is repeatedly input at the same timing as time t111 to t113.

<Explanation of timing in case of phase shift of 4 phases on transmission side>
Next, the timing of each signal when a four-phase phase shift is performed on the transmission side will be described. FIG. 20 is a diagram illustrating the timing when the transmission side performs a four-phase phase shift with respect to the signal. In FIG. 20, the horizontal axis represents time. In addition, in the symbols g923, g924, and g925, the vertical axis is the amplitude.
Symbol g921 indicates a control signal from the control signal generator to the phase shift unit, symbol g922 indicates a control signal from the control signal generator to the direction selector, and symbol g923 indicates a transmission signal. Reference numeral g924 indicates a reception signal leaked directly from the transmission signal, reference numeral g925 indicates a reception signal (desired wave) due to SAW delay, and reference numeral g926 indicates a control signal from the control signal generation unit to the phase reverse shift unit and the correlation unit. .

First, the timing of the control signal input to the phase shift unit will be described.
As shown in the image of g921, a control signal for outputting the 0 phase is input during the period from time t201 to t204 and during the period from time t213 to t216, and π / 2 phase is input during the period from time t204 to t207. A control signal to be output is input. Further, as indicated by an image denoted by reference numeral g921, a control signal that outputs a π phase is input during a period from time t207 to t210, and a control signal that outputs a 3π / 2 phase is output during a period from time t204 to t207. Entered.

Next, the timing of the control signal input to the direction selection unit and the transmission timing of the transmission signal will be described.
As shown in the image denoted by reference numeral g922, in the period from time t201 to t202, the period from time t204 to t205, the period from time t207 to t208, the period from time t210 to t211, and the period from time t213 to t214, A control signal to be connected to the terminal Tx is input. Thereby, in each period mentioned above, a transmission signal is transmitted as the image of the code | symbol g923 shows.
In addition, as indicated by the image denoted by g922, in the period from time t202 to t204, the period from time t205 to t207, the period from time t208 to t210, the period from time t211 to t213, and the period from time t214 to t216, A control signal to be connected to the third terminal Rx is input.

Next, the timing at which the received signal is received and the timing of the control signal input to the phase inverse shift unit and the correlation unit will be described.
As indicated by an image denoted by reference numeral g924, a reception signal due to leakage of the transmission signal is received during each period in which a control signal to be connected to the first terminal Tx is input to the directionality selection unit.
On the other hand, as indicated by an image denoted by reference numeral g925, at time t203, t206, t209, t212, and t215, the received signal is received as a SAW delayed reception signal.
Since the signal to be acquired is a SAW-delayed received signal shown in the image denoted by reference numeral g925, a control signal is input to the phase reverse shift unit and the correlation unit in accordance with this timing. That is, as shown by the image of g926, a control signal that outputs the zero phase is input during the period from time t203 to t206, and a control signal that outputs the π / 2 phase is output during the period from time t206 to t209. Entered. Further, as indicated by the image denoted by reference numeral g926, a control signal that outputs a π phase is input during a period from time t209 to t212, and a control signal that outputs a 3π / 2 phase is output during a period from time t212 to t215. Entered.
The example shown in FIG. 20 is an example in which the phase is 2π, and after time t213, the control signal is repeatedly input at the same timing as time t201.

<Explanation of timing in case of phase shift of 4 phases on receiving side>
Next, the timing of each signal when the receiving side performs a four-phase phase shift will be described. FIG. 21 is a diagram illustrating the timing when the receiving side performs a four-phase phase shift with respect to the signal. In FIG. 21, the horizontal axis represents time. In addition, in the signs g933, g934, and g935, the vertical axis is the amplitude.
Symbol g931 indicates a control signal from the control signal generator to the phase shift unit, symbol g932 indicates a control signal from the control signal generator to the direction selector, and symbol g933 indicates a transmission signal. Further, symbol g934 indicates a reception signal leaked directly from the transmission signal, symbol g935 indicates a reception signal (desired wave) due to SAW delay, and symbol g936 indicates a control signal from the control signal generator to the phase reverse shift unit and the correlation unit. .

First, the timing of the control signal input to the phase shift unit will be described.
As shown in the image indicated by reference sign g931, a control signal for outputting phase 0 is input during the period from time t303 to t306, and a control signal for outputting π / 2 phase is input during the period from time t306 to t309. The Further, as indicated by an image denoted by reference numeral g931, a control signal for outputting a π phase is input during a period from time t309 to t312, and a control signal for outputting a 3π / 2 phase is output during a period from time t312 to t315. Entered.

Next, the timing of the control signal input to the direction selection unit and the transmission timing of the transmission signal will be described.
As indicated by the image g932, in the period from time t301 to t302, the period from time t304 to t305, the period from time t307 to t308, the period from time t310 to t311, and the period from time t313 to t314, A control signal to be connected to the terminal Tx is input. Thereby, in each period mentioned above, a transmission signal is transmitted as the image of the code | symbol g933 shows.
In addition, as indicated by an image denoted by g932, in the period from time t302 to t304, the period from time t305 to t307, the period from time t308 to t310, the period from time t311 to t313, and the period from time t314 to t316, A control signal to be connected to the third terminal Rx is input.

Next, the timing at which the received signal is received and the timing of the control signal input to the phase inverse shift unit and the correlation unit will be described.
As indicated by an image denoted by reference numeral g934, a reception signal due to leakage of the transmission signal is received during each period in which a control signal to be connected to the first terminal Tx is input to the directionality selection unit.
On the other hand, as indicated by an image denoted by reference numeral g935, at time t303, t306, t309, t312 and t315, the received signal is received as a SAW-delayed signal.
Since the signal to be acquired is a SAW-delayed received signal shown in the image denoted by reference numeral g935, a control signal is input to the phase reverse shift unit and the correlation unit in accordance with this timing. That is, as indicated by an image denoted by reference numeral g936, a control signal for outputting phase 0 is input during a period from time t303 to t306, and a control signal for outputting π / 2 phase is input during a period from time t306 to t309. Entered. Further, as indicated by an image denoted by reference numeral g936, a control signal that outputs a π phase is input during a period from time t309 to t312, and a control signal that outputs a 3π / 2 phase is output during a period from time t312 to t315. Entered.
The example shown in FIG. 21 is an example in which the phase is 2π, and after time t315, the control signal is repeatedly input at the same timing as time t303.

Here, the SAW devices 111 and 111A will be further described.
The propagation speed of SAW is low compared with the propagation speed of radio waves, and the signal does not change when viewed in a predetermined period (this state is defined as time invariant in the present invention). As described above, since the SAW device 111 or 111A is time-invariant, by the configuration described in the present invention, the phase can be shifted, and time-division transmission can be performed sequentially, so that an orthogonal demodulation operation can be realized equivalently. Complex signals can be acquired by time division.

  In the first to seventh embodiments described above, the transmission power amplifiers (103, 203, 303, 403, 503, 603, 703, 803) are connected to the SAW devices (111, 211, 311, 411, 511, 511, 611). , 711, 811) are connected to the transmission electrode 11-1a and the transmission electrode 11-1b, and the reception power amplification unit (104, 204, 304, 404, 504, 604, 704, 804) is connected to the SAW device (111, 211). 311, 411, 511, 611, 711, 811) have been described as being connected to the receiving electrode 11-2 a and the receiving electrode 11-2 b, but the present invention is not limited thereto. The transmission power amplification units (103, 203, 303, 403, 503, 603, 703, 803) are connected to the transmission antenna, and the reception power amplification units (104, 204, 304, 404, 504, 604, 704, 804) are connected. It may be connected to a receiving antenna.

In addition, a program for realizing a part of the functions of the transmission / reception device is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to execute processing of each unit. You may go. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

Furthermore, in each of the embodiments described above, the amplitude of the time division signal is constant.
However, the present invention is similarly applied to obtain a complex signal corresponding to the response of the sensor unit 110 to the QAM modulated wave by setting the amplitude of such a time-division signal to a desired value different for each phase. Applicable.
Further, in each of the above-described embodiments, the sensor units 110, 210, 310, 410, 510, 610, 710, 810, and 910 obtain the response to the time division signal in series for each phase, or are estimated or simulated. As long as it is a circuit or device to be performed, it is not limited to a passive circuit, and may be replaced by an active circuit.

Furthermore, each embodiment mentioned above is not limited to the structure shown in FIG.2, FIG.3, FIG.4, FIG.5, FIG.10, FIG.13, FIG.14, FIG.15, FIG. All or a part of these elements may be merged (integrated) in any combination, or function distribution and additional distribution may be achieved in any form.
(1) Sensor unit 110, 210, 310, 410, 510, 610, 710, 810, 910
(2) Reception frequency converters 105, 205, 305, 405, 505, 605, 705, 805, 905
(3) LPF 106, 206, 306, 306a, 306b, 406, 506, 606, 706a, 706b, 806, 906
(4) AD converters 107, 207, 307, 307a, 307b, 407, 507, 607, 707a, 707b, 807, 907
(5) Phase reverse shift units 308, 408, 508, 608, 708, 808, 908
(6) Correlator 309, 409, 509, 609, 709, 809, 909
(7) Reception retiming unit 621
(8) I / Q separators 108 and 208

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

100, 200, 300, 400, 500, 600, 700, 800, 900: transmission / reception device,
101, 201, 301, 401, 301, 501, 601, 701, 801, 901: control signal generator,
102, 209, 302, 412, 302, 502, 602, 702, 802, 902: phase shift unit,
103, 203, 303, 403, 303, 503, 603, 703, 803, 903: transmission power amplification unit,
104, 204, 304, 404, 304, 504, 604, 704, 804, 904: received power amplification unit,
105, 205, 305, 315, 321a, 321b, 405, 505, 605, 705, 805, 905: reception frequency converter,
106, 206, 306, 306a, 306b, 406, 506, 606, 706a, 706b, 806, 906: LPF section,
107, 207, 307, 307a, 307b, 407, 507, 607, 707a, 707b, 807, 907: AD conversion unit,
108, 208: I / Q separator,
110, 210, 310, 410, 310, 510, 610, 710, 810, 910: sensor unit,
111, 111A, 211, 311, 411, 311, 511, 611, 711, 811: SAW device,
151,251,351,451,351,551,651,751,851,951: transmitter,
152,252,352,452,352,552,652,752,852,952: receiving part,
153,353,353,553,753,853,953: delay adjustment unit,
308, 408, 308, 508, 608, 708, 808, 908: phase reverse shift unit,
309, 409, 309, 509, 609, 709, 809, 909: correlation unit,
521, 721, 821: Transmission retiming section,
621: Reception retiming section,
842a, 842b: DA converter,
841: Transmission frequency converter,
920: Directionality selection unit

Claims (8)

Carrier wave generating means for alternately generating two carrier waves having phases different from each other by π / 2;
Signal processing means for individually extracting the components having different phases by π / 2 in synchronization with the carrier wave generating means from a sequence of steady responses output by a predetermined circuit according to the two carrier waves. An alternative quadrature modulator / demodulator characterized by that. Phase variable means for alternately setting the phase of the steady response output by the predetermined circuit in accordance with the carrier wave to two values different from each other by π / 2;
Signal processing means for individually extracting components of different phases by π / 2 in synchronization with the phase variable means from a response sequence in which the phase of the response is set by the phase variable means. A featured alternative quadrature modem. Carrier wave generating means for cyclically generating carrier waves of a plurality of p (≧ 3) whose phases are different by (2π / p) each;
Signal processing means for individually extracting (2π / p) different phase components in synchronization with the carrier wave generating means from a response sequence output by a predetermined circuit in response to the plurality of p carrier waves. An alternative quadrature modulator / demodulator characterized by that. Phase variable means for cyclically setting the phase of a response output by a predetermined circuit in accordance with a carrier wave to a plurality of p (≧ 3) values different by (2π / p),
Signal processing means for individually extracting components having different phases by (2π / p) in synchronization with the phase varying means from a response sequence in which the phase of the response is set by the phase varying means. An alternative quadrature modulator / demodulator characterized by that. The alternative quadrature modulator / demodulator according to claim 3,
The carrier wave generating means includes
An alternative quadrature modulator / demodulator, wherein the phase jump width of the plurality of p carriers is maintained at (2π / p). The alternative quadrature modulator / demodulator according to claim 4,
The phase varying means is
An alternative quadrature demodulator / demodulator, characterized in that a phase jump width set in a response output from the predetermined circuit is maintained at (2π / p). The alternative quadrature modulator / demodulator according to claim 3,
The carrier wave generating means includes
An alternative quadrature modulator / demodulator, wherein the jump width of the phase of the plurality of p carriers is set at random. The alternative quadrature modulator / demodulator according to claim 4,
The phase varying means is
An alternative quadrature modulator / demodulator, wherein a phase jump width set in a response output from the predetermined circuit is set at random.

Images