JP2017038130A - Radio wave transmitter/receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the impact of a transmission radio wave on the reception side circuit furthermore.SOLUTION: A radio wave transmitter/receiver includes: an output unit outputting a main signal and an image component; a signal generation unit generating a first local signal and a second local signal having the same frequency, on the basis of the image component outputted from the output unit; a modulation circuit including a first mixer for modulating the first local signal generated by the signal generation unit, by using the main signal outputted from the output unit; a transmission unit for transmitting a radio wave, including the first local signal modulated by the modulation circuit, to an object area; a reception unit for receiving the radio wave from the object area and generating a reception signal; a demodulation circuit including a second mixer for demodulating the reception signal generated by the reception unit, by using the second local signal; and a control unit for controlling to reduce the level of the second local signal, in a transmission period for transmitting a radio wave from the transmission unit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a radio wave transmission / reception device, and more particularly to a radio wave transmission / reception device that transmits and receives radio waves.

  In Japanese Patent No. 5282585 (Patent Document 1), a transmission signal amplified by a transmission output amplifier is transmitted from an antenna via a transmission / reception signal coupling unit, and a reception signal received by the antenna is coupled to the transmission / reception signal coupling. Describes a TDD transmission / reception apparatus that inputs to a reception input amplifier via a unit. The TDD transmission / reception device monitors the output current or output voltage of the preamplifier in front of the transmission output amplifier, and whether or not the output current or output voltage exceeds a predetermined overoutput current value or overoutput voltage value. An overpower determination means for determining the reception power by means of an overpower determination signal of the preamplifier for the transmission output amplifier by the overpower determination means, provided between the transmission / reception signal coupling unit and the reception input amplifier. A receiving switch for cutting off a signal path for inputting a signal to the receiving input amplifier.

  Japanese Patent Laying-Open No. 2004-31345 (Patent Document 2) describes a transceiver in which a common antenna is used for a transmission processing unit and a reception processing unit. The transceiver includes a circulator connected to an antenna, an isolator connected to the circulator, and an SPST circuit connected to the isolator. The transmission processing unit is connected to the circulator. The reception processing unit is connected to the SPST circuit, and the SPST circuit is controlled so that a signal from the isolator to the reception processing unit is not passed during transmission while a signal from the isolator to the reception processing unit is passed during reception. .

  Japanese Patent No. 3276856 (Patent Document 3) describes a wireless transmission / reception device. A radio transmission / reception device includes a transmission circuit that transmits a signal whose band is spread by a pseudo-noise signal by converting the frequency using an output of a high-frequency oscillator that has passed through a distributor, and receives a reception signal based on the transmission signal. Is provided between the distributor and the transmitter circuit, and the frequency converted by the receiver circuit for detecting the correlation with the pseudo-noise signal by converting the frequency with the output of the high-frequency oscillator through the distributor And an isolator that suppresses the transmission signal from entering the receiving side.

Japanese Patent No. 5282585 JP 2004-31345 A Japanese Patent No. 3276856

Edited and published by the Institute of Electronics, Information and Communication Engineers Supervised by Takashi Yoshida, “Revised Radar Technology”, revised edition, Corona, October 1996, P275-280 Ken Gentile, “Super-Nyquist Operation of the AD9912 Yields a High RF Output Signal”, [online], ANALOG DEVICES Application Note, [URL June / 2015, w / p. analog. com / media / en / technical-documentation / application-notes / AN-939. pdf>

  In the radio wave transmission / reception device described in Patent Document 1 or 2, an isolator or a switch is provided between the antenna and the reception side circuit to suppress the influence of the transmission radio wave on the reception side circuit.

  Further, in the radio wave transmission / reception device described in Patent Document 3, an isolator is provided between the transmission side circuit and the distributor, thereby suppressing the transmission radio wave from entering the reception side circuit.

  For example, when the isolation between the circuit on the transmission side and the circuit on the reception side is not sufficient, a part of the transmission radio wave may enter the circuit on the reception side, and the signal level in the circuit on the reception side may fluctuate. In such a case, for example, an erroneous demodulation result is output, or the reception dynamic range is reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a radio wave transmission / reception apparatus that can further suppress the influence of a transmission radio wave on a circuit on the reception side.

  (1) In order to solve the above-described problem, a radio wave transmission / reception apparatus according to an aspect of the present invention is a radio wave transmission / reception apparatus, an output unit that outputs a main signal and an image component, and the output unit that outputs the signal Based on the image component, a signal generation unit that generates a first local signal and a second local signal having the same frequency, and the first local signal generated by the signal generation unit is output from the output unit A modulation circuit including a first mixer for modulating using a main signal; a transmitter for transmitting a radio wave including the first local signal modulated by the modulation circuit to a target area; and a radio wave from the target area A receiving unit that receives and generates a received signal; and the second local signal generated by the signal generating unit that generates the received signal generated by the receiving unit. Used comprises a demodulation circuit including a second mixer for demodulating, and a control section for controlling to reduce the level of said second local signal in a transmission period for transmitting a radio wave from the transmitting unit.

  The present invention can be realized not only as a radio wave transmission / reception apparatus including such a characteristic processing unit, but also as a system including the radio wave transmission / reception apparatus, or as a method using such characteristic processing as a step. Or can be realized as a program for causing a computer to execute such steps. Further, it can be realized as a semiconductor integrated circuit that realizes part or all of the radio wave transmitting / receiving apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the influence on the circuit on the receiving side of a transmission radio wave can be suppressed more.

FIG. 1 is a diagram showing a configuration of a radar system according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the radio wave transmission / reception apparatus in the radar system according to the embodiment of the present invention. FIG. 3 is a diagram illustrating examples of waveforms of the fundamental wave and the clock signal generated by the output unit and the clock generation circuit in the radio wave transmission / reception apparatus according to the embodiment of the present invention. FIG. 4 is a diagram illustrating an example of each waveform of the main signal and the clock signal generated in the output unit and the clock generation circuit in the radio wave transmission / reception apparatus according to the embodiment of the present invention. FIG. 5 is a diagram showing a configuration of an output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 6 is a diagram showing a configuration of a modulation unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 7 is a diagram showing a configuration of a signal generation unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 8 is a diagram illustrating an example of the fundamental wave generated by the output unit in the radio wave transmission / reception device according to the embodiment of the present invention and an image component of the fundamental wave. FIG. 9 is a diagram showing a configuration of a transmission unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 10 is a diagram showing a configuration of a receiving unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 11 is a diagram showing a configuration of a demodulation unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 12 is a timing chart showing the operation of the control unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 13 is a timing chart showing the operation of the control unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 14 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 15 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 16 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. FIG. 17 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  First, the contents of the embodiment of the present invention will be listed and described.

  (1) The radio wave transmission / reception device according to the embodiment of the present invention is a radio wave transmission / reception device, which is the same based on the output unit that outputs a main signal and an image component, and the image component output from the output unit. A signal generating unit that generates a first local signal and a second local signal having a frequency, and the first local signal generated by the signal generating unit is modulated using the main signal output from the output unit. A modulation circuit including a first mixer, a transmitter for transmitting a radio wave including the first local signal modulated by the modulation circuit to a target area, and generating a reception signal by receiving the radio wave from the target area And a second mixer for demodulating the received signal generated by the receiver using the second local signal generated by the signal generator. Comprising a demodulation circuit including a support, and said control unit in a transmission period for transmitting a radio wave from the transmitting unit performs control to reduce the level of the second local signal.

  As described above, the control for reducing the level of the second local signal in the transmission period in which the reception signal is highly likely to be affected by the transmission radio wave causes the level of the reception signal demodulated by the second mixer to be set in the transmission period. Can be reduced. As a result, it is possible to avoid an erroneous demodulation result being output or a dynamic range from being lowered on the receiving side, so that the influence of the transmission radio wave in various processes using the demodulated received signal can be reduced. Can be suppressed. Accordingly, it is possible to further suppress the influence of the transmission radio wave on the circuit on the reception side.

  (2) Preferably, the said control part performs control which makes the level of a said 1st local signal small further in the receiving period which should receive the electromagnetic wave from the said target area in the said receiving part.

  As described above, the control for reducing the level of the first local signal in the reception period in which the reception signal is processed can reduce the level of the first local signal modulated by the first mixer in the reception period. Therefore, the power of the transmission radio wave including the first local signal after the modulation can be reduced. As a result, the power of the transmission radio wave entering the reception side circuit can be reduced, so that the influence of the transmission radio wave on the signal processing in the reception side circuit can be further suppressed.

  (3) Preferably, the said control part performs control which makes the level of the said main signal small further in the receiving period which should receive the electromagnetic wave from the said target area in the said receiving part.

  As described above, the control for reducing the level of the main signal in the reception period in which the reception signal is processed reduces the level of the first local signal after the modulation using the main signal in the reception period. Therefore, the power of the transmission radio wave including the first local signal after modulation can be reduced. As a result, the power of the transmission radio wave entering the reception side circuit can be reduced, so that the influence of the transmission radio wave on the signal processing in the reception side circuit can be further suppressed.

  (4) Preferably, the output unit includes a digital-to-analog converter for generating the image component, and the control unit performs control to reduce a level of the image component in the transmission period. 2 Reduce the level of the local signal.

  As described above, the configuration in which the image component is generated using the digital-analog converter that operates in accordance with the clock signal can reduce or increase the level of the second local signal in a short time of about one cycle of the clock signal. Therefore, signal processing in the circuit on the receiving side can be started at a faster timing after the transmission period expires, or the signal processing can be continued until a timing closer to the start of the transmission period. This makes it possible to effectively use the received signal while further suppressing the influence of the transmission radio wave on the circuit on the receiving side.

  (5) Preferably, the output unit includes a direct digital synthesizer for generating the image component, and the control unit performs control to reduce a level of the image component in the transmission period, thereby 2 Reduce the level of the local signal.

  In this way, the configuration in which the image component is generated using the direct digital synthesizer that operates according to the clock signal can reduce or increase the level of the second local signal in a short time of about one cycle of the clock signal. Therefore, signal processing in the circuit on the receiving side can be started at a faster timing after the transmission period expires, or the signal processing can be continued until a timing closer to the start of the transmission period. This makes it possible to effectively use the received signal while further suppressing the influence of the transmission radio wave on the circuit on the receiving side.

  (6) Preferably, the radio wave transmitting / receiving apparatus further includes a detection unit that detects an object in the target area based on the received signal demodulated by the demodulation circuit.

  With such a configuration, for example, even when a guard period is not provided between the transmission period and the reception period, the influence of the transmission radio wave in various processes using the demodulated reception signal can be suppressed. The device can be used as a high-performance radio wave sensor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated. Moreover, you may combine arbitrarily at least one part of embodiment described below.

[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a radar system according to an embodiment of the present invention. Referring to FIG. 1, radar system 301 includes radio wave transmission / reception device 101 and control device 151.

  In FIG. 1, one radio transmission / reception device 101 is representatively shown, but a plurality of radio transmission / reception devices 101 may be provided.

  The radio wave transmission / reception device 101 is, for example, a radio wave sensor. Specifically, Non-Patent Document 1 (Edited and published by Takashi Yoshida, edited by the Institute of Electronics, Information and Communication Engineers, “Revised Radar Technology”, Revised Edition, Corona, October 1996, P275 -280).

  The radio wave sensor 101 transmits, for example, a pulsed radio wave, that is, a transmission pulse Tw, to the target area A1, and receives a pulsed radio wave, that is, a reflected pulse Rw from the target area A1. The reflected pulse Rw received by the radio wave sensor 101 includes the target reflected pulse Trw reflected by the target Tgt.

  For example, the radio wave transmitting / receiving apparatus 101 detects the target Tgt in the target area A1 based on the received reflected pulse Rw. The object Tgt is a human, for example. The target object Tgt is not limited to a human being, but may be any object or animal that can reflect radio waves.

  More specifically, the radio wave transmission / reception device 101 operates according to the control of the control device 151, for example. For example, the radio wave transmission / reception device 101 detects a target distance Lt from itself to the target object Tgt in the target area A1, and notifies the control device 151 of the detection result. Details of the target distance Lt will be described later.

[Configuration of radio wave transmitter / receiver]
FIG. 2 is a diagram showing a configuration of a radio wave transmitting / receiving apparatus in the radar system according to the embodiment of the present invention.

  Referring to FIG. 2, radio wave transmitting / receiving apparatus 101 includes a transmission unit 21, an output unit 22, a control unit 24, a multi-channel AD (analog / digital) converter (ADC) 25, a detection unit 26, and a clock generation circuit. 27, a reception unit 28, a signal generation unit 29, an oscillator 30, a modulation unit 31, a demodulation unit 32, and a buffer unit 33.

  The oscillator 30 generates a local signal Lo3 having a frequency of 77 GHz and a sine wave, for example, and outputs the generated local signal Lo3 to the transmission unit 21 and the reception unit 28.

[Clock signal]
FIG. 3 is a diagram illustrating examples of waveforms of the fundamental wave and the clock signal generated by the output unit and the clock generation circuit in the radio wave transmission / reception apparatus according to the embodiment of the present invention. In FIG. 3, the horizontal axis indicates time, and the vertical axis indicates level.

  Referring to FIGS. 2 and 3, clock generation circuit 27 generates, for example, a clock signal. Specifically, the clock generation circuit 27 generates, for example, a rectangular wave clock signal CS shown in FIG. FIG. 3 shows a clock signal CS for five cycles, for example.

  For example, the control unit 24 performs control to set the frequency of the clock signal CS generated in the clock generation circuit 27. Specifically, the control unit 24 sets the frequency of the clock signal CS to 1 GHz, for example.

  The clock generation circuit 27 generates a clock signal CS having a set frequency of 1 GHz under the control of the control unit 24, and outputs the generated clock signal CS to the output unit 22, the control unit 24, the multi-channel AD converter 25, and the buffer unit To 33.

[Fundamental wave]
The fundamental waves FST and FSR shown in FIG. 3 have a sine waveform having a period of 5 ns, that is, a frequency of 200 MHz and an amplitude of 100.

  For example, the control unit 24 is based on the frequency of the clock signal CS and the periods and amplitudes of the fundamental waves FST and FSR for each rising edge timing of the clock signal received from the clock generation circuit 27 (hereinafter also referred to as clock timing). Thus, the levels of the fundamental waves FST and FSR at the timing are calculated, and digital signals FTDS and FRDS indicating the calculated levels are output to the output unit 22, respectively.

[Main signal]
FIG. 4 is a diagram illustrating an example of each waveform of the main signal and the clock signal generated in the output unit and the clock generation circuit in the radio wave transmission / reception apparatus according to the embodiment of the present invention. In FIG. 4, the horizontal axis indicates time, and the vertical axis indicates level.

  Referring to FIGS. 2 and 4, main signal MS is based on, for example, the waveform shown in FIG. 11.8 (c) on page 278 of Non-Patent Document 1, more specifically, a code sequence according to a Barker code of N = 7. Has a waveform.

  Here, for example, a period in which the main signal MS vibrates in the level range of +100 to −100, that is, a period from timing t0 to t7 is a transmission period Tt in which radio waves are to be transmitted from the transmission unit 21. For example, a modulation pulse, that is, a transmission pulse Tw is transmitted from the radio wave transmitting / receiving apparatus 101 in the transmission period Tt. The length of the transmission period Tt corresponds to the pulse width Tp of the main signal MS, that is, the transmission pulse width Tp of the transmission pulse Tw.

  Timings from timing t0 to Tp / 7 are timings t1 to t7, respectively. The level of the main signal MS is zero until timing t0 and after timing t7. The level of the main signal MS is +100 from the timing t0 to the timing t3, is −100 from the timing t3 to the timing t5, is +100 from the timing t5 to the timing t6, and after the timing t6 to the timing t7. Up to -100.

  For example, the control unit 24 sets the transmission period Tt and the reception period Tr in which the radio wave from the target area A1 is to be received in the reception unit 28. More specifically, for example, when the user sets the period Trep as the repetition period of the transmission period Tt and the period Trep as the repetition period of the transmission period Tt, the control unit 24 clocks the transmission period Tw having a length of 84 ns. Set according to the timing. For example, the control unit 24 sets a period from the end timing of a certain transmission period Tw to the start timing of the next transmission period Tw as the reception period Tr. That is, the transmission period Tt and the reception period Tr do not overlap.

  Moreover, the control part 24 hold | maintains the amplitude data which are the data for producing | generating the main signal MS shown, for example in FIG. The amplitude data includes, for example, seven numerical values “+100, +100, +100, −100, −100, +100, −100” in order from the top.

  For example, when the set transmission period Tt arrives, the control unit 24 sequentially acquires each numerical value included in the amplitude data from the top every 12 ns, and generates a digital signal ITDS indicating the acquired numerical value at each clock timing. To the output unit 22.

  More specifically, the control unit 24 acquires the first numerical value included in the amplitude data, that is, +100, at the timing t0 that is the start timing of the set transmission period Tt. The control unit 24 continues to generate the digital signal ITDS indicating the acquired numerical value at each clock timing and output it to the output unit 22 until timing t1.

  Then, at the timing t1, the control unit 24 acquires the second numerical value from the top, that is, +100, included in the amplitude data. The control unit 24 continues to generate the digital signal ITDS indicating the acquired numerical value at each clock timing and output it to the output unit 22 until timing t2.

  Similarly, for the third and subsequent numerical values included in the amplitude data, the control unit 24 generates a digital signal ITDS indicating the numerical value at each clock timing and outputs the digital signal ITDS to the output unit 22.

  Further, when the output of the digital signal ITDS indicating each numerical value in the amplitude data to the output unit 22 is completed, the control unit 24 performs the following processing in the reception period Tr. That is, the control unit 24 generates, for example, a digital signal ITDS indicating zero at each clock timing, and outputs the generated digital signal ITDS to the output unit 22.

  In the transmission period Tt and the reception period Tr, the control unit 24 generates a digital signal QTDS indicating, for example, zero for each clock timing, and outputs the generated digital signal QTDS to the output unit 22.

  For example, the control unit 24 creates setting information including the length of the transmission period Tt, amplitude data, and the frequency of the clock signal CS, and outputs the created setting information to the detection unit 26.

  For example, the control unit 24 creates a timing signal TSS indicating the timing at which the transmission pulse Tw is transmitted from the radio wave sensor 101 at the timing t0 that is the start timing of the set transmission period Tt, and sends the timing signal TSS to the detection unit 26. Output.

  Note that the control unit 24, for example, provides a guard period having a time width corresponding to one or more clock timings before and after the transmission period so that the transmission period and the reception period are not directly adjacent to each other. Also good.

  More specifically, for example, when the guard period is provided before the transmission period, the control unit 24 sets the guard period, the transmission period, and the reception period to be repeatedly arranged in this order. For example, when providing a guard period after the transmission period, the control unit 24 sets the transmission period, the guard period, and the reception period so that they are repeatedly arranged in this order. For example, when providing a guard period both before and after the transmission period, the control unit 24 sets the transmission period, the guard period, the reception period, and the guard period so that they are repeatedly arranged in this order.

  FIG. 5 is a diagram showing a configuration of an output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. Referring to FIG. 5, output unit 22 includes a multi-channel DA (digital analog) converter (DAC) 71. Multi-channel DA converter 71 includes input terminals 72I, 72Q, 72T, 72R and output terminals 73I, 73Q, 73T, 73R.

  FIG. 6 is a diagram showing a configuration of a modulation unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. Referring to FIG. 6, modulation unit 31 includes a modulation circuit 10. The modulation circuit 10 includes low-pass filters 42I and 42Q, a first mixer 43I, a mixer 43Q, a phase shifter 44, and a synthesizer 45.

  FIG. 7 is a diagram showing a configuration of a signal generation unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. Referring to FIG. 7, signal generation unit 29 includes bandpass filters 51T and 51R and amplifiers 52T and 52R.

  Referring to FIG. 2 and FIGS. 5 to 7, output unit 22 outputs main signal MS and image components. More specifically, the output unit 22 outputs, for example, the main signal MS, the first image component, and the second image component.

  For example, the multi-channel DA converter 71 in the output unit 22 generates the main signal MS and the first image component and the second image component, and sends the generated main signal MS and each image component to the modulation unit 31 and the signal generation unit 29, respectively. Output.

  Specifically, the multi-channel DA converter 71, for example, receives the digital signals ITDS, QTDS and FTDS, FRDS received from the control unit 24 according to the timing of the clock signal CS received from the clock generation circuit 27, that is, the clock timing, respectively. It converts into QTAS, FTAS, and FRAS, and outputs it to the modulation | alteration part 31 and the signal generation part 29. FIG.

  More specifically, multi-channel DA converter 71 receives digital signals ITDS, QTDS, FTDS, and FRDS from control unit 24 at input terminals 72I, 72Q, 72T, and 72R, respectively.

  For example, when the numerical value indicated by digital signal ITDS received at input terminal 72I is +100 or −100 at each clock timing, multi-channel DA converter 71 is, for example, an analog that is main signal MS having maximum voltage Vmax or minimum voltage Vmin. A signal ITAS is generated and output from the output terminal 73I to the low-pass filter 42I in the modulator 31.

  Further, when the numerical value indicated by the digital signal ITDS received at the input terminal 72I is zero, the multi-channel DA converter 71 generates, for example, an analog signal ITAS having an intermediate voltage between the maximum voltage Vmax and the minimum voltage Vmin from the output terminal 73I. It outputs to the low pass filter 42I in the modulation part 31.

  When the numerical value indicated by the digital signal QTDS received at the input terminal 72Q is zero, the multi-channel DA converter 71 generates, for example, the analog signal QTAS having the intermediate voltage and outputs the analog signal QTAS from the output terminal 73Q to the low-pass filter 42Q in the modulator 31. To do.

  The multi-channel DA converter 71 generates an analog signal FTAS having a voltage corresponding to the numerical value indicated by the digital signal FTDS received at the input terminal 72T, and outputs the analog signal FTAS from the output terminal 73T to the bandpass filter 51T in the signal generation unit 29.

  The multi-channel DA converter 71 generates an analog signal FRAS having a voltage corresponding to the numerical value indicated by the digital signal FRDS received at the input terminal 72R, and outputs the analog signal FRAS from the output terminal 73R to the bandpass filter 51R in the signal generation unit 29.

  FIG. 8 is a diagram illustrating an example of the fundamental wave generated by the output unit in the radio wave transmission / reception device according to the embodiment of the present invention and an image component of the fundamental wave.

  Referring to FIG. 8, Non-Patent Document 2 (Ken Gentile, “Super-Nyquist Operation of the AD9912 Yields a High RF Output Signal”, [online], ANALOG DEVICES Application Month 30 [Heisei 27] , As described on the Internet <URL: http://www.analog.com/media/en/technical-documentation/application-notes/AN-939.pdf>), the fundamental wave FST shown in FIG. The analog signal FTAS based on the digital signal FTDS indicating discrete values includes the following components.

  That is, the analog signal FTAS includes, for example, a fundamental wave component FCT having a frequency of 200 MHz and image components ICT1, ICT2, ICT3, and ICT4 that are first image components having frequencies of 800 MHz, 1200 MHz, 1800 MHz, 2200 MHz, and 2800 MHz, respectively. And ICT5.

  Similarly, the analog signal FRAS based on the digital signal FRDS indicating discrete values of the fundamental wave FSR includes, for example, a fundamental wave component FCR having a frequency of 200 MHz, and frequencies of 800 MHz, 1200 MHz, 1800 MHz, 2200 MHz, and 2800 MHz, respectively. Image components ICR1, ICR2, ICR3, ICR4, and ICR5, which are second image components, are included.

  Referring to FIGS. 2 and 7 again, the signal generation unit 29 generates a first local signal and a second local signal having the same frequency based on the image component output from the output unit 22. More specifically, for example, the signal generation unit 29 generates a first local signal and a second local signal having the same frequency based on the first image component and the second image component output from the output unit 22, for example. .

  Specifically, the signal generation unit 29 has a frequency of 1800 MHz based on the first image component and the second image component output from the output terminals 73T and 73R of the multi-channel DA converter 71 in the output unit 22, for example. Local signals Lo1 and Lo2 are generated as a first local signal and a second local signal, respectively.

  More specifically, the band pass filter 51T in the signal generation unit 29 attenuates, for example, components below the frequency Fl and components above the frequency Fu shown in FIG. 8 among the frequency components of the analog signal FTAS received from the output terminal 73T. .

  That is, among the fundamental wave component FCT and the image components ICT1 to ICT5 output from the output terminal 73T, the image component ICT3 passes through the band-pass filter 51T.

  For example, the band pass filter 51R attenuates the frequency component equal to or lower than the frequency Fl and the frequency component equal to or higher than the frequency Fu among the frequency components of the analog signal FRAS received from the output terminal 73R.

  That is, among the fundamental wave component FCR and the image components ICR1 to ICR5 output from the output terminal 73R, the image component ICR3 passes through the bandpass filter 51R.

  As shown in FIG. 8, the amplitudes of the image components ICT3 and ICR3 are amplified because they are smaller than the amplitudes of the fundamental waves FCT and FCR. For example, the amplifier 52T amplifies the analog signal FTAS that has passed through the bandpass filter 51T, that is, the image component ICT3, and outputs the amplified analog signal FTAS to the modulation unit 31 as the local signal Lo1.

  For example, the amplifier 52R amplifies the analog signal FRAS that has passed through the bandpass filter 51R, that is, the image component ICR3, and outputs the amplified analog signal FRAS to the demodulator 32 as the local signal Lo2.

  Referring to FIGS. 2 and 6 again, for example, modulation unit 31 modulates local signal Lo1 generated by signal generation unit 29 using main signal MS output from output unit 22, that is, analog signal ITAS. .

  More specifically, the low-pass filter 42I in the modulation circuit 10 included in the modulation unit 31 is a component having a predetermined frequency or higher among the frequency components of the analog signal ITAS received from the output terminal 73I of the multi-channel DA converter 71 in the output unit 22. Is attenuated.

  For example, the first mixer 43I modulates the local signal Lo1 received from the amplifier 52T in the signal generation unit 29 by using the analog signal ITAS that has passed through the low-pass filter 42I. Then, the first mixer 43I outputs the modulated local signal Lo1 to the synthesizer 45. Here, for example, when the analog signal ITAS does not change with time during the period other than the transmission period Tt, the first mixer 43I does not output a signal to the synthesizer 45.

  For example, the phase shifter 44 shifts the phase of the local signal Lo1 received from the amplifier 52T in the signal generation unit 29 by π / 2, and outputs the local signal Lo1 shifted in phase to the mixer 43Q.

  The low-pass filter 42Q attenuates a component having a predetermined frequency or higher among the frequency components of the analog signal QTAS received from the output terminal 73Q of the multi-channel DA converter 71 in the output unit 22.

  For example, the mixer 43Q modulates the local signal Lo1 received from the phase shifter 44 using the analog signal QTAS that has passed through the low-pass filter 42Q. Here, since the analog signal QTAS remains the intermediate voltage and does not change with time, the local signal Lo1 is not modulated. Therefore, the mixer 43Q does not output a signal to the synthesizer 45.

  The combiner 45 combines the modulated local signal Lo1 received from the first mixer 43I and the analog signal received from the mixer 43Q, and outputs the combined analog signal to the transmission unit 21.

  Here, since the synthesizer 45 does not receive a signal from the mixer 43Q, for example, the synthesizer 45 outputs the modulated local signal Lo1 received from the first mixer 43I to the transmission unit 21.

  FIG. 9 is a diagram showing a configuration of a transmission unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  Referring to FIG. 9, transmission unit 21 includes a mixer 46, a power amplifier 47, and a transmission antenna 48.

  The transmitter 21 transmits a radio wave including the local signal Lo1 modulated by the modulation circuit 10 to the target area A1.

  More specifically, the mixer 46 in the transmission unit 21 multiplies, for example, the modulated local signal Lo1 received from the synthesizer 45 and the local signal Lo3 received from the oscillator 30 to modulate the 1800 MHz band modulated local signal. Lo1 is converted into a 78.8 GHz band modulated local signal Lo1 that is a transmission pulse Tw, that is, a radio wave. Then, the mixer 46 outputs the converted radio wave to the power amplifier 47.

  The power amplifier 47 amplifies the radio wave received from the mixer 46 and transmits the amplified radio wave to the target area A 1 via the transmission antenna 48.

  FIG. 10 is a diagram showing a configuration of a receiving unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  Referring to FIG. 10, receiving unit 28 includes a mixer 66, a low noise amplifier 67, and a receiving antenna 68.

  The receiving unit 28 receives a radio wave from the target area A1 and generates a reception signal. More specifically, the low noise amplifier 67 in the receiving unit 28 amplifies the 78.8 GHz band analog signal RAS that is the reflected pulse Rw received by the receiving antenna 68, and the amplified 78.8 GHz band analog signal RAS in the mixer 66. Output to.

  For example, the mixer 66 multiplies the analog signal RAS in the 78.8 GHz band received from the low noise amplifier 67 by the local signal Lo3 received from the oscillator 30 to thereby obtain the analog signal RAS in the 78.8 GHz band as a reception signal in the 1800 MHz band. To the analog signal RAS. Then, the mixer 46 outputs the converted 1800 MHz band analog signal RAS to the demodulator 32.

  FIG. 11 is a diagram showing a configuration of a demodulation unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  Referring to FIG. 11, demodulation unit 32 includes demodulation circuit 11. The demodulation circuit 11 includes second mixers 63I and 63Q and a phase shifter 64.

  The demodulator 32 demodulates the reception signal generated by the receiver 28 using the local signal Lo2 generated by the signal generator 29.

  More specifically, the second mixer 63I included in the demodulation circuit 11 in the demodulation unit 32 uses the reception signal received from the mixer 66, that is, the analog signal RAS in the 1800 MHz band, and the local signal Lo2 received from the amplifier 52R in the signal generation unit 29. The baseband I component analog signal IRAS is generated. Then, the second mixer 63I outputs the generated analog signal IRAS to the multi-channel AD converter 25.

  For example, the phase shifter 64 shifts the phase of the local signal Lo2 received from the amplifier 52R in the signal generation unit 29 by π / 2, and outputs the local signal Lo2 shifted in phase to the second mixer 63Q.

  The second mixer 63Q demodulates the reception signal received from the mixer 66, that is, the analog signal RAS in the 1800 MHz band using the local signal Lo2 received from the phase shifter 64 and having a phase shifted by π / 2, and the Q component in the baseband The analog signal QRAS is generated. Then, the second mixer 63Q outputs the generated analog signal QRAS to the multi-channel AD converter 25.

  Referring to FIG. 2 again, multi-channel AD converter 25, for example, receives analog signals IRAS, QRAS received from demodulation unit 32 in accordance with the timing of clock signal CS received from clock generation circuit 27, that is, the digital signal IRDS, QRDS. Respectively. The multi-channel AD converter 25 outputs, for example, digital signals IRDS and QRDS to the buffer unit 33.

  For example, the buffer unit 33 receives the digital signals IRDS and QRDS from the multi-channel AD converter 25 at each timing of the clock signal CS received from the clock generation circuit 27, that is, at each clock timing, and accumulates the received digital signals IRDS and QRDS. At this time, for example, the buffer unit 33 associates the digital signals IRDS and QRDS with these digital signals as sampling timings.

  For example, the detection unit 26 detects the target Tgt in the target area A1 based on the received signal demodulated by the demodulation circuit 11.

  More specifically, the detection unit 26 detects a target distance Lt, which is a distance from the radio wave transmitting / receiving apparatus 101 to the target object Tgt in the target area A1, based on the received signal demodulated by the demodulation circuit 11, for example.

  More specifically, for example, the detection unit 26 acquires the length of transmission period Tt, amplitude data, and the frequency of the clock signal CS from the setting information received from the control unit 24, and acquires the acquired length of transmission period Tt, amplitude data. Based on the frequency of the clock signal CS, the detection function x (t) representing the main signal MS shown in FIG. 4 is created.

  The detection unit 26 sets the origin of the time t, which is a variable of the detection function x (t), for example, to the timing at which the timing signal TSS is received from the control unit 24, that is, the timing at which the transmission pulse Tw is transmitted from the radio wave transmitting / receiving device 101. .

  Further, the detection unit 26 receives, for example, a reception function r (t) representing a time spectrum of the reflected pulse Rw corresponding to the transmission pulse Tw from the digital signal IRDS or QRDS stored in the buffer unit 33 and the corresponding sampling timing. Create

  The detection unit 26 sets the origin of time t, which is a variable of the reception function r (t), for example, at the timing at which the timing signal TSS is received from the control unit 24 in the same manner as the origin of the detection function x (t).

  For example, the detection unit 26 performs a convolution operation on the detection function x (t) and the reception function r (t) according to Equation (11.4) on page 277 of Non-Patent Document 1, thereby providing a function f that can include a compressed pulse. Pulse compression processing for calculating (t) is performed.

  For example, when the function f (t) includes a compression pulse based on the object reflection pulse Trw from the object Tgt, the detection unit 26 multiplies the time corresponding to the peak position of the compression pulse by (c / 2). The detected value is detected as the target distance Lt. For example, the detection unit 26 transmits the detected target distance Lt to the control device 151.

  FIG. 12 is a timing chart showing the operation of the control unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. In FIG. 12, the horizontal axis indicates time, and the vertical axis indicates level.

  FIG. 12 shows the timing of switching from the reception period Tr to the transmission period Tt, that is, the waveforms of the clock signal CS, the main signal MS, the fundamental wave FSR, and the fundamental wave FST before and after the timing t0 shown in FIG.

  In FIG. 12, the values indicated by the digital signals ITDS, FTDS, and FRDS of 5 ns before and after the timing t0 are indicated by white squares, black circles, and white circles, respectively.

  FIG. 13 is a timing chart showing the operation of the control unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention. In FIG. 13, the horizontal axis indicates time and the vertical axis indicates level.

  FIG. 13 shows the waveforms of the clock signal CS, the main signal MS, the fundamental wave FSR, and the fundamental wave FST at the timing of switching from the transmission period Tt to the reception period Tr, that is, 5 ns before and after the timing t7 shown in FIG.

  In FIG. 13, the values indicated by the digital signals ITDS, FTDS, and FRDS 5 ns before and after the timing t7 are indicated by white squares, black circles, and white circles, respectively.

  Referring to FIGS. 12 and 13, control unit 24 performs control to reduce the level of local signal Lo2 in transmission period Tt. More specifically, the control unit 24 reduces the level of the local signal Lo2 by controlling, for example, the generation of the second image component by the output unit 22 in the transmission period Tt.

  Specifically, the control unit 24 reduces the level of the local signal Lo2, for example, by performing control to reduce the level of the image component ICR3 in the transmission period Tt.

  In this example, the control unit 24 performs control to make the level of the local signal Lo2 zero, for example, by preventing the image component ICR3 from being generated in the transmission period Tt.

  More specifically, for example, the control unit 24 sets zero at each clock timing in the transmission period Tt, that is, each clock timing after the timing t0 shown in FIG. 12, and each clock timing before the timing t7 shown in FIG. The digital signal FRDS shown is output to the input terminal 72R of the multi-channel DA converter 71 in the output unit 22.

  The output terminal 73R of the multi-channel DA converter 71 outputs an analog signal FRAS having an intermediate voltage to the bandpass filter 51R in the signal generation unit 29 at each clock timing in the transmission period Tt. The analog signal FRAS at each clock timing in the transmission period Tt does not include the oscillating fundamental wave component FCR, and therefore does not include the image component ICR3. Accordingly, the level of the local signal Lo2 becomes zero at each clock timing in the transmission period Tt.

  The control unit 24 is not limited to the configuration in which the digital signal FRDS indicating zero is output to the output unit 22 at each clock timing in the transmission period Tt, and the control unit 24 outputs the digital signal FRDS indicating a certain numerical value other than zero. The structure which outputs to the output part 22 may be sufficient.

  The control unit 24 may be configured to reduce the amplitude of the image component ICR3 by performing control to reduce the amplitude of the fundamental wave component FCR at each clock timing in the transmission period Tt.

  More specifically, for example, the control unit 24 outputs the digital signal FRDS based on the fundamental wave FSR having an amplitude of 100 to the output unit 22 at each clock timing in the reception period Tr. On the other hand, for example, at each clock timing in the transmission period Tt, the control unit 24 outputs the digital signal FRDS based on the fundamental wave FSR whose amplitude is smaller than 100 to the output unit 22.

  Further, for example, when providing a guard period before and after the transmission period Tt, the control unit 24 performs control to reduce the level of the image component ICR3 at each clock timing of the guard period and the transmission period Tt. Decrease the Lo2 level.

  For example, the control unit 24 performs control to reduce the level of the local signal Lo1 in the reception period Tr. More specifically, the control unit 24 reduces the level of the local signal Lo1 by controlling the generation of the first image component by the output unit 22 in the reception period Tr, for example.

  Specifically, the control unit 24 reduces the level of the local signal Lo1, for example, by performing control to reduce the level of the image component ICT3 in the reception period Tr.

  In this example, the control unit 24 performs control to make the level of the local signal Lo1 zero, for example, by preventing the image component ICT3 from being generated in the reception period Tr.

  More specifically, for example, the control unit 24 sets zero at each clock timing in the reception period Tr, that is, each clock timing before the timing t0 shown in FIG. 12, and each clock timing after the timing t7 shown in FIG. The digital signal FTDS shown is output to the input terminal 72T of the multi-channel DA converter 71 in the output unit 22.

  The output terminal 73T of the multi-channel DA converter 71 outputs an analog signal FTAS having an intermediate voltage to the band pass filter 51T in the signal generation unit 29 at each clock timing in the reception period Tr. The analog signal FTAS at each clock timing in the reception period Tr does not include the oscillating fundamental wave component FCT, and therefore does not include the image component ICT3. As a result, the level of the local signal Lo1 becomes zero at each clock timing in the reception period Tr.

  The control unit 24 is not limited to the configuration in which the digital signal FTDS indicating zero is output to the output unit 22 at each clock timing in the reception period Tr, but the control unit 24 outputs the digital signal FTDS indicating a certain numerical value other than zero. The structure which outputs to the output part 22 may be sufficient.

  The control unit 24 may be configured to reduce the amplitude of the image component ICT3 by performing control to reduce the amplitude of the fundamental wave component FCT at each clock timing in the reception period Tr.

  More specifically, for example, the control unit 24 outputs a digital signal FTDS based on the fundamental wave FST having an amplitude of 100 to the output unit 22 at each clock timing in the transmission period Tt. On the other hand, for example, the control unit 24 outputs the digital signal FTDS based on the fundamental wave FST having an amplitude smaller than 100 to the output unit 22 at each clock timing in the reception period Tr.

  Further, for example, when providing a guard period before and after the transmission period Tt, the control unit 24 performs control to reduce the level of the image component ICT3 at each clock timing of the guard period and the reception period Tr. Decrease the Lo1 level.

  For example, the control unit 24 performs control to reduce the level of the main signal MS in the reception period Tr.

  In this example, for example, as described above, the control unit 24 outputs the digital signal ITDS indicating zero to the input terminal 72I of the multi-channel DA converter 71 in the output unit 22 at each clock timing in the reception period Tr. For example, the control unit 24 outputs a digital signal ITDS indicating any numerical value in the amplitude data to the input terminal 72I at each clock timing in the transmission period Tt.

  The control unit 24 is not limited to the configuration in which the digital signal ITDS indicating zero is output to the input terminal 72I at each clock timing in the reception period Tr, but the control unit 24 is the digital signal ITDS indicating a certain numerical value other than zero. May be output to the input terminal 72I.

[Modification 1 of output section]
FIG. 14 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  Referring to FIG. 14, an output unit 22M1 which is a modification of output unit 22 is a multi-channel direct digital synthesizer (hereinafter referred to as a multi-channel digital synthesizer), instead of multi-channel DA converter 71, as compared with output unit 22 shown in FIG. (Also referred to as DDS). The multi-channel DDS 86 includes waveform data buffer units 87I, 87Q, 87T, 87R and DA converters 88I, 88Q, 88T, 88R.

  The multi-channel DDS 86 in the output unit 22M1 generates, for example, the main signal MS and the first image component and the second image component, and outputs the generated main signal MS and each image component to the modulation unit 31 and the signal generation unit 29, respectively. .

  Referring to FIGS. 2 and 14 again, control unit 24 reduces the level of local signal Lo2, for example, by performing control to reduce the level of image component ICR3 in transmission period Tt.

  Specifically, for example, the control unit 24 satisfies each timing relationship in the timing charts shown in FIGS. 12 and 13, each numerical value indicated by the digital signal ITDS for the repetition period Trep, each numerical value indicated by the digital signal FTDS, and the digital signal. Each numerical value indicated by FRDS is stored in waveform data buffer units 87I, 87T and 87R, respectively.

  For example, the control unit 24 stores each numerical value indicated by the digital signal QTDS for the repetition period Trep in the waveform data buffer unit 87Q.

  For example, the control unit 24 creates a timing signal TSS and outputs the timing signal TSS to the multi-channel DDS 86 and the detection unit 26 at the timing t0 that is the start timing of the set transmission period Tt.

  For example, when the waveform data buffer units 87I, 87Q, 87T, and 87R receive the timing signal TSS from the control unit 24, the waveform data buffer units 87I, 87Q, 87T, and 87R are stored by the control unit 24 at the timing of the rising edge of the clock signal received from the clock generation circuit 27. The obtained numerical values are sequentially acquired from the head, and digital signals indicating the acquired numerical values are output to the DA converters 88I, 88Q, 88T, and 88R, respectively.

  The DA converters 88I, 88Q, 88T, and 88R convert the respective digital signals received from the waveform data buffer units 87I, 87Q, 87T, and 87R into analog signals ITAS, QTAS, FTAS, and FRAS, for example, according to the clock timing.

  For example, the DA converters 88I and 88Q output the converted analog signals ITAS and QTAS to the low-pass filters 42I and 42Q in the modulation unit 31, respectively.

  DA converters 88T and 88R, for example, output converted analog signals FTAS and FRAS to bandpass filters 51T and 51R in signal generation unit 29, respectively.

[Modification Example 2 of Output Unit]
FIG. 15 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  Referring to FIG. 15, an output unit 22M2, which is a modification of output unit 22, includes DA converters 41I, 41Q, 41T, and 41R instead of multi-channel DA converter 71, as compared with output unit 22 shown in FIG. Including.

  The DA converters 41I, 41Q, 41T, and 41R receive the digital signals ITDS, QTDS, FTDS, and FRDS, respectively, from the control unit 24 at each clock timing.

  For example, when the numerical value indicated by the digital signal ITDS received from the control unit 24 is +100 or −100, the DA converter 41I generates, for example, an analog signal ITAS having the maximum voltage Vmax or the minimum voltage Vmin, and the low-pass filter in the modulation unit 31 To 42I.

  When the numerical value indicated by the digital signal ITDS received from the control unit 24 is zero, the DA converter 41I generates, for example, an analog signal ITAS having an intermediate voltage and outputs the analog signal ITAS to the low-pass filter 42I in the modulation unit 31.

  When the numerical value indicated by the digital signal QTDS received from the control unit 24 is zero, the DA converter 41Q generates, for example, the analog signal QTAS having the intermediate voltage and outputs the analog signal QTAS to the low-pass filter 42Q in the modulation unit 31.

  For example, the DA converter 41T generates an analog signal FTAS having a voltage corresponding to a numerical value indicated by the digital signal FTDS received from the control unit 24, and outputs the analog signal FTAS to the bandpass filter 51T in the signal generation unit 29.

  For example, the DA converter 41R generates an analog signal FRAS having a voltage corresponding to a numerical value indicated by the digital signal FRDS received from the control unit 24, and outputs the analog signal FRAS to the bandpass filter 51R in the signal generation unit 29.

[Variation 3 of output section]
FIG. 16 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  Referring to FIG. 16, an output unit 22M3, which is a modification of output unit 22, is referred to as a direct digital synthesizer (hereinafter also referred to as DDS) instead of multi-channel DA converter 71, as compared with output unit 22 shown in FIG. ) 91I, 91Q, 91T, 91R are included. Each of DDS 91I, 91Q, 91T, and 91R includes a waveform data buffer unit 92 and a DA converter 93.

  The operations of the waveform data buffer unit 92 and the DA converter 93 in the DDS 91I are the same as those of the waveform data buffer unit 87I and the DA converter 88I in the multi-channel DDS 86 shown in FIG.

  The operations of the waveform data buffer unit 92 and the DA converter 93 in the DDS 91Q are the same as those of the waveform data buffer unit 87Q and the DA converter 88Q in the multi-channel DDS 86 shown in FIG.

  The operations of the waveform data buffer unit 92 and the DA converter 93 in the DDS 91T are the same as those of the waveform data buffer unit 87T and the DA converter 88T in the multi-channel DDS 86 shown in FIG.

  The operations of the waveform data buffer unit 92 and the DA converter 93 in the DDS 91R are the same as those of the waveform data buffer unit 87R and the DA converter 88R in the multi-channel DDS 86 shown in FIG.

  Referring to FIGS. 2 and 16 again, for example, control unit 24 satisfies the timing relationship in the timing charts shown in FIGS. 12 and 13 and each numerical value indicated by digital signal ITDS corresponding to repetition period Trep, digital signal FTDS Each numerical value indicated and each numerical value indicated by the digital signal FRDS are stored in the waveform data buffer unit 92 in the DDS 91I, 91T, and 91R, respectively.

  For example, the control unit 24 stores each numerical value indicated by the digital signal QTDS for the repetition period Trep in the waveform data buffer unit 92 in the DDS 91Q.

  For example, the control unit 24 creates a timing signal TSS and outputs the timing signal TSS to the multi-channel DDS 86 and the detection unit 26 at the timing t0 that is the start timing of the set transmission period Tt.

[Modification 4 of the output unit]
FIG. 17 is a diagram showing a configuration of a modified example of the output unit in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention.

  17, output unit 22M4, which is a modification of output unit 22, has DA converters 41I and 41Q, DDS 91T and 91R instead of multi-channel DA converter 71, as compared with output unit 22 shown in FIG. Including. Each of DDS 91T and 91R includes a waveform data buffer unit 92 and a DA converter 93.

  The operations of the DA converters 41I and 41Q are the same as those of the DA converters 41I and 41Q in the output unit 22M2 shown in FIG.

  The operations of the waveform data buffer unit 92 and the DA converter 93 in the DDS 91T are the same as those of the waveform data buffer unit 87T and the DA converter 88T in the multi-channel DDS 86 shown in FIG.

  The operations of the waveform data buffer unit 92 and the DA converter 93 in the DDS 91R are the same as those of the waveform data buffer unit 87R and the DA converter 88R in the multi-channel DDS 86 shown in FIG.

  Referring to FIGS. 2 and 17 again, for example, when timing t0 which is the start timing of transmission period Tt arrives, control unit 24 sequentially acquires each numerical value included in the amplitude data from the top every 12 ns. The digital signal ITDS indicating the acquired numerical value is generated at each clock timing and output to the DA converter 41I.

  For example, when timing t0 arrives, control unit 24 generates digital signal QTDS indicating, for example, zero at each clock timing, and outputs the generated digital signal QTDS to DA converter 41Q.

  Further, for example, at the timing t0, the control unit 24 stores the numerical values indicated by the digital signal FTDS corresponding to the fundamental wave FST for the transmission period Tt, that is, 84 ns, in the waveform data buffer unit 92 in the DDS 91T, and at the timing signal TSS. Is output to the output unit 22M4 and the detection unit 26.

  In the DDS 91T in the output unit 22M4, the waveform data buffer unit 92 stores, for example, each numerical value by the control unit 24. When the timing signal TSS is received from the control unit 24, the waveform data buffer unit 92 stores each numerical value stored at each clock timing. The digital signal indicating the acquired numerical value is output to the DA converter 93 in order from the top.

  For example, when the output of the digital signal indicating the last numerical value among the stored numerical values to the DA converter 93 is completed at the end timing of the transmission period Tt, the waveform data buffer unit 92 in the DDS 91T newly starts from the control unit 24. Output of the digital signal to the DA converter 93 is stopped until the timing signal TSS is received, that is, until the reception period Tr expires.

  For example, when the timing t7 arrives, the control unit 24 stores each numerical value indicated by the digital signal FRDS corresponding to the fundamental wave FSR for the reception period Tr in the waveform data buffer unit 92 in the DDS 91R, and from the own radio wave sensor 101. A timing signal TSE indicating the timing at which transmission of the transmission pulse Tw is completed is generated and output to the output unit 22M4.

  In the DDS 91R in the output unit 22M4, the waveform data buffer unit 92 stores, for example, each numerical value by the control unit 24. When the timing signal TSE is received from the control unit 24, the waveform data buffer unit 92 stores each numerical value stored at each clock timing. The digital signal indicating the acquired numerical value is output to the DA converter 93 in order from the top.

  For example, when the output of the digital signal indicating the last numerical value among the stored numerical values to the DA converter 93 is completed at the end timing of the reception period Tr, the waveform data buffer unit 92 in the DDS 91R newly starts from the control unit 24. Until the timing signal TSE is received, that is, until the transmission period Tt expires, the output of the digital signal to the DA converter 93 is stopped.

  In the radio wave transmitting / receiving apparatus according to the embodiment of the present invention, the signal generation unit 29 outputs the first local signal and the second local signal based on the image component ICT3 of the fundamental wave FST and the image component ICR3 of the fundamental wave FSR. Although it was set as the structure which each produces | generates, it is not limited to this. For example, the signal generation unit 29 may be configured to generate the first local signal and the second local signal based on the image component of the main signal, or an image component other than the image components ICT3 and ICR3, for example, the image component The first local signal and the second local signal may be generated based on ICT4 and ICR4.

  Moreover, although the radio wave transmission / reception apparatus according to the embodiment of the present invention is configured to separately include the transmission antenna 48 for transmission and the reception antenna 68 for reception, the present invention is not limited to this. The radio wave transmitting / receiving apparatus 101 may be configured to electrically connect a common antenna used for transmission and reception to, for example, a transmission side circuit and a reception side circuit via a circulator. Even with such a configuration, it is possible to achieve an effect of further suppressing the influence of the transmission radio wave on the circuit on the reception side.

  By the way, in the radio wave transmission / reception apparatus described in Patent Document 1 or 2, an isolator or a switch is provided between the antenna and the reception side circuit to suppress the influence of the transmission radio wave on the reception side circuit.

  Further, in the radio wave transmission / reception device described in Patent Document 3, an isolator is provided between the transmission side circuit and the distributor, thereby suppressing the transmission radio wave from entering the reception side circuit.

  For example, when the isolation between the circuit on the transmission side and the circuit on the reception side is not sufficient, a part of the transmission radio wave may enter the circuit on the reception side, and the signal level in the circuit on the reception side may fluctuate. In such a case, for example, an erroneous demodulation result is output, or the reception dynamic range is reduced.

  More specifically, when an isolator or switch is provided between the antenna and the circuit on the receiving side as in the radio wave transmitting / receiving device described in Patent Document 1 or 2, the isolator or switch provided in the preceding stage of the receiving circuit is used. The loss of the signal causes an increase in the reception noise level.

  Further, for example, when a guard period is not provided between the transmission period and the reception period as in the pulse compression radar described in Non-Patent Document 1, when the response of the isolator or the switch is not sufficiently high, the isolator or Signal processing in the receiving circuit may start before the switch is completely switched. In such a case, part of the transmitted radio wave enters the circuit on the receiving side.

  On the other hand, in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention, the output unit 22 outputs the main signal MS and the image component. The signal generation unit 29 generates a local signal Lo1 and a local signal Lo2 having the same frequency based on the image component output from the output unit 22. The modulation circuit 10 in the modulation unit 31 includes a first mixer 43I for modulating the local signal Lo1 generated by the signal generation unit 29 using the main signal MS output from the output unit 22. The transmitter 21 transmits a radio wave including the local signal Lo1 modulated by the modulation circuit 10 to the target area A1. The receiving unit 28 receives a radio wave from the target area A1 and generates a reception signal. The demodulation circuit 11 in the demodulation unit 32 includes second mixers 63I and 63Q for demodulating the reception signal generated by the reception unit 28 using the local signal Lo2 generated by the signal generation unit 29. And the control part 24 performs control which makes the level of the local signal Lo2 small in the transmission period Tt which should transmit an electromagnetic wave from the transmission part 21. FIG.

  As described above, the level of the received signal after demodulation by the second mixers 63I and 63Q is controlled by performing the control to reduce the level of the local signal Lo2 in the transmission period Tt in which the received signal is highly likely to be affected by the transmission radio wave. The transmission period Tt can be reduced. As a result, it is possible to avoid an erroneous demodulation result being output or a dynamic range from being lowered on the receiving side, so that the influence of the transmission radio wave in various processes using the demodulated received signal can be reduced. Can be suppressed. Accordingly, it is possible to further suppress the influence of the transmission radio wave on the circuit on the reception side.

  Further, in the radio wave transmission / reception apparatus according to the embodiment of the present invention, the control unit 24 controls the reception unit 28 to reduce the level of the local signal Lo1 during the reception period Tr in which the radio wave from the target area A1 should be received.

  As described above, the level of the local signal Lo1 modulated by the first mixer 43I can be reduced in the reception period Tr by performing the control to reduce the level of the local signal Lo1 in the reception period Tr in which the reception signal is processed. Therefore, the power of the transmission radio wave including the modulated local signal Lo1 can be reduced. As a result, the power of the transmission radio wave entering the reception side circuit can be reduced, so that the influence of the transmission radio wave on the signal processing in the reception side circuit can be further suppressed.

  Further, in the radio wave transmission / reception apparatus according to the embodiment of the present invention, the control unit 24 controls the reception unit 28 to reduce the level of the main signal MS in the reception period Tr in which the radio wave from the target area A1 should be received.

  In this way, the control for reducing the level of the main signal MS in the reception period Tr in which the reception signal is processed allows the level of the local signal Lo1 after the modulation using the main signal MS to be performed in the reception period Tr. Since it can be reduced, the power of the transmission radio wave including the modulated local signal Lo1 can be reduced. As a result, the power of the transmission radio wave entering the reception side circuit can be reduced, so that the influence of the transmission radio wave on the signal processing in the reception side circuit can be further suppressed.

  Further, in the radio wave transmitting / receiving apparatus according to the embodiment of the present invention, the output unit 22 includes a multi-channel DA converter 71 for generating an image component. Then, the control unit 24 reduces the level of the local signal Lo2 by performing control to reduce the level of the image component ICR3 in the transmission period Tt.

  As described above, the configuration in which the image component ICR3 is generated using the multi-channel DA converter 71 that operates according to the clock signal CS can reduce or increase the level of the local signal Lo2 in a short time of about one cycle of the clock signal CS. Therefore, the signal processing in the receiving circuit can be started at a faster timing after the transmission period Tt expires, or the signal processing can be continued until a timing closer to the start of the transmission period Tt. This makes it possible to effectively use the received signal while further suppressing the influence of the transmission radio wave on the circuit on the receiving side.

  In the radio wave transmitting / receiving apparatus according to the embodiment of the present invention, output unit 22M1 includes a multi-channel DDS 86 for generating image component ICR3. Then, the control unit 24 reduces the level of the local signal Lo2 by performing control to reduce the level of the image component ICR3 in the transmission period Tt.

  As described above, the configuration of generating the image component ICR3 using the multi-channel DDS 86 that operates according to the clock signal CS reduces or increases the level of the local signal Lo2 in a short time of about one cycle of the clock signal CS. Therefore, the signal processing in the receiving circuit can be started at a faster timing after the transmission period Tt expires, or the signal processing can be continued until the timing closer to the start of the transmission period Tt. This makes it possible to effectively use the received signal while further suppressing the influence of the transmission radio wave on the circuit on the receiving side.

  Moreover, in the radio wave transmission / reception apparatus according to the embodiment of the present invention, the detection unit 26 detects the object Tgt in the target area A1 based on the received signal demodulated by the demodulation circuit 11.

  With such a configuration, for example, even when a guard period is not provided between the transmission period Tt and the reception period Tt, it is possible to suppress the influence of transmission radio waves in various processes using the received signal after demodulation. The radio wave transmission / reception device 101 can be used as a radio wave sensor with good performance.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The above description includes the following features.

[Appendix 1]
A radio wave transmitting and receiving device,
An output unit for outputting a main signal, a first image component and a second image component;
A signal generation unit configured to generate a first local signal and a second local signal having the same frequency based on the first image component and the second image component output from the output unit;
A modulation circuit including a first mixer for modulating the first local signal generated by the signal generation unit using the main signal output from the output unit;
A transmitter that transmits a radio wave including the first local signal modulated by the modulation circuit to a target area;
A receiving unit that receives a radio wave from the target area and generates a reception signal;
A demodulation circuit including a second mixer for demodulating the reception signal generated by the reception unit using the second local signal generated by the signal generation unit;
A control unit that reduces the level of the second local signal by controlling generation of the second image component by the output unit in a transmission period in which radio waves are to be transmitted from the transmission unit;
The main signal has a pulsed waveform based on a code sequence;
The radio transmission / reception apparatus, wherein a length of the transmission period is a pulse width of the main signal.

DESCRIPTION OF SYMBOLS 10 Modulation circuit 11 Demodulation circuit 21 Transmission part 22 Output part 22M1,22M2,22M3,22M4 Output part 24 Control part 25 Multichannel AD converter (ADC)
26 detection unit 27 clock generation circuit 28 reception unit 29 signal generation unit 30 oscillator 31 modulation unit 32 demodulation unit 33 buffer unit 41I, 41Q, 41T, 41R DA converter (DAC)
42I, 42Q Low-pass filter 43I First mixer 43Q mixer 44 Phase shifter 45 Synthesizer 46 Mixer 47 Power amplifier 48 Transmitting antenna 51T, 51R Bandpass filter 52T, 52R amplifier 63I, 63Q Second mixer 64 Phase shifter 66 Mixer 67 Low noise Amplifier 68 Receiving antenna 71 Multi-channel DA converter (DAC)
72I, 72Q, 72T, 72R Input terminal 73I, 73Q, 73T, 73R Output terminal 86 Multi-channel DDS
87I, 87Q, 87T, 87R Waveform data buffer unit 88I, 88Q, 88T, 88R DA converter 91I, 91Q, 91T, 91R Direct digital synthesizer (DDS)
92 Waveform Data Buffer Unit 93 DA Converter 101 Radio Wave Transmitter / Receiver 151 Controller 301 Radar System

Claims (6)

A radio wave transmitting and receiving device,
An output unit for outputting a main signal and an image component;
A signal generation unit that generates a first local signal and a second local signal having the same frequency based on the image component output from the output unit;
A modulation circuit including a first mixer for modulating the first local signal generated by the signal generation unit using the main signal output from the output unit;
A transmitter that transmits a radio wave including the first local signal modulated by the modulation circuit to a target area;
A receiving unit that receives a radio wave from the target area and generates a reception signal;
A demodulation circuit including a second mixer for demodulating the reception signal generated by the reception unit using the second local signal generated by the signal generation unit;
A radio wave transmission / reception apparatus comprising: a control unit that performs control to reduce a level of the second local signal in a transmission period in which radio waves are to be transmitted from the transmission unit.   The radio transmission / reception apparatus according to claim 1, wherein the control unit further performs control to reduce a level of the first local signal in a reception period in which the reception unit should receive radio waves from the target area.   The radio wave transmission / reception apparatus according to claim 1, wherein the control unit further performs control to reduce a level of the main signal in a reception period in which the radio wave from the target area is to be received by the reception unit. The output unit includes a digital-analog converter for generating the image component,
4. The radio wave according to claim 1, wherein the control unit reduces the level of the second local signal by performing control to reduce the level of the image component in the transmission period. 5. Transmitter / receiver. The output unit includes a direct digital synthesizer for generating the image component,
5. The radio wave according to claim 1, wherein the control unit reduces the level of the second local signal by performing control to reduce the level of the image component during the transmission period. 6. Transmitter / receiver. The radio wave transmission / reception device further includes:
The radio wave transmission / reception apparatus according to claim 1, further comprising: a detection unit configured to detect an object in the target area based on the reception signal demodulated by the demodulation circuit.

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