Radar system

Abstract

To provide a radar system to be easily mounted on a rotation mechanism.SOLUTION: A radar system includes N-number of antenna devices, a distributor / synthesizer, and a transmitter / receiver. The antenna device includes an antenna, a transmission / reception discriminator, a frequency conversion section, and an antenna frequency discriminator. The transmitter / receiver includes a clock oscillator, a transmission section, a transmission / reception frequency discriminator, and an A / D conversion section. The frequency conversion section converts a reception RF signal into a reception IF signal of a different frequency for each antenna, so as to output the signal to the antenna frequency discriminator. The distributor / synthesizer distributes a transmission RF signal from the transmission / reception frequency discriminator into N-number of signals, outputs the signals to the N-number of antenna frequency discriminators, and outputs a synthetic reception IF signal being the signal obtained by synthesizing the reception IF signals from the N-number of antenna frequency discriminators to the transmission / reception frequency discriminator.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a radar system in which an antenna is mounted on a rotating mechanism. [Background technology]

[0002] The most basic form of radar is a search radar, which uses a mechanically driven fan-beam pattern antenna, which has a narrow horizontal beam and a relatively wide vertical beam. This type of radar consists of a pair of antennas and a transmitter / receiver, and determines the location of a reflecting object by the time between transmission and reception and the antenna's beam angle. Because it has a simple configuration and can be implemented relatively inexpensively, it is widely used in marine radars and other applications.

[0003] In recent years, autonomous driving technology has been widely adopted in automobiles. Autonomous driving in automobiles uses multiple sensors, such as millimeter-wave radar, stereo cameras, and LiDAR (Light Detection and Ranging), to recognize the surrounding environment and determine driving operations (see, for example, Patent Document 1). The trend toward autonomous driving is no exception for ships. However, one difference between automobiles and ships is the time it takes to change course, with ships being significantly slower. Therefore, ships need to understand a wider range of their surroundings. Because millimeter-wave radar has a limited maximum detection range, low frequencies, such as the X-band, which have traditionally been used for autonomous ship navigation, are suitable. Furthermore, for autonomous driving, a high update rate (frequency at which measurement results are updated) is desirable from the perspective of more detailed understanding of the surrounding environment and responding to unexpected events. Since the update rate of measurement results generally depends on the rotation speed of the antenna, a high rotation speed is desirable for radar antennas. Patent Document 2 shows a method for using multiple radars in different directions to reduce rotation speed.

[0004] The technology of Patent Document 2 is a radar having multiple combinations of antenna devices and transmitting / receiving devices. Fig. 1 shows an example of a radar having one antenna mounted on a rotation mechanism. Fig. 1(A) is a plan view of the antenna. The antenna rotates horizontally. Fig. 1(B) is an output screen from the radar. The dark shaded parts are updated. Fig. 2 shows an example of a radar having four antennas mounted on a rotation mechanism. Fig. 2(A) is a plan view of the antenna. The antenna rotates horizontally. Fig. 2(B) is an output screen from the radar. The dark shaded parts are updated. It can be seen that having four antennas results in a higher update rate even if the rotation speed is the same. Patent Document 2 is an example using multiple antennas. Fig. 3 shows an example of a radar having multiple combinations of antenna devices and transmitting / receiving devices. The radar system of Fig. 3 has N antenna devices 9101, ..., 910 N and N transceiver units 9301, ..., 930 N N antenna devices 9101, ..., 910 N and N transceiver units 9301, ..., 930 N are mounted on a rotation mechanism 950. Transmitting and receiving devices 9301, ..., 930 N The connection to the outside is made via a rotary joint 940. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-66240 A [Patent Document 2] Japanese Patent Application Publication No. 9-236656 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional marine radars use lower frequencies than millimeter waves, which means the antenna dimensions are large, and because they are mechanically driven, there is a limit to how fast the antenna can be rotated. While it is possible to change the antenna's pointing angle control to an electronic scanning system, this would result in a large and expensive device.

[0007] Marine radars are widely used around the world and are readily available, so they are also being used for purposes other than marine applications. One example is the monitoring of the operation of small flying objects (drones), which is likely to become more common in the future. However, lightweight design is a key requirement for typical drones, and the aircraft's materials and size also work to reduce the radar cross section, making detection difficult. One way to address this is to reduce the antenna rotation speed, increasing the number of times the target is irradiated with radio waves, thereby improving detection performance through the cumulative effect. However, this makes tracking difficult for targets that move at high speeds. In the configuration shown in Figure 3, antenna devices 9101, ..., 910 are attached to a rotation mechanism 950. N and transmitting / receiving devices 9301, ..., 930 N In addition, the number of wires required for connection to the outside increases, which also causes the problem of the rotary joint 940 becoming larger.

[0008] An object of the present invention is to provide a radar system that can be easily mounted on a rotation mechanism. [Means for solving the problem]

[0009] The radar system of the present invention includes N antenna devices, a divider / combiner, and a transceiver. N is an integer equal to or greater than 2. The N antenna devices and the divider / combiner are arranged on a rotation mechanism so that the beam angles of the N antenna devices do not overlap. The antenna device includes an antenna, a transmission / reception discriminator, a frequency converter, and an antenna frequency discriminator. The transceiver includes a clock oscillator, a transmitter, a transmission / reception frequency discriminator, and an A / D converter. The transmission / reception discriminator outputs a transmission RF signal from the antenna frequency discriminator to the antenna, and outputs a received RF signal from the antenna to the frequency converter. The frequency converter converts the received RF signal into a reception IF signal with a different frequency for each antenna, and outputs it to the antenna frequency discriminator. The antenna frequency discriminator outputs the transmission RF signal from the divider / combiner to the transmission / reception discriminator, and outputs the received IF signal from the frequency converter to the divider / combiner. The divider / combiner divides the transmit RF signal from the transmit / receive frequency discriminator into N signals and outputs them to N antenna frequency discriminators, and outputs a combined receive IF signal, which is a signal obtained by combining the receive IF signals from the N antenna frequency discriminators, to the transmit / receive frequency discriminator. The clock oscillator generates a clock signal for processing within the transmitter / receiver. The transmitter outputs the transmit RF signal to the transmit / receive frequency discriminator. The transmit / receive frequency discriminator outputs the transmit RF signal from the transmitter to the divider / combiner, and also outputs the combined receive IF signal from the divider / combiner or N receive IF signals, which are obtained by discriminating the combined receive IF signal into receive IF signals from the N antenna frequency discriminators, to the A / D converter. The A / D converter converts the signal from the transmit / receive frequency discriminator into a digital signal. [Effects of the Invention]

[0010] According to the radar system of the present invention, the received IF signal sent from the antenna device to the transceiver device has a different frequency for each antenna. Therefore, there is no need to provide a transceiver device for each antenna device, and therefore there is no need to mount the transceiver device on the rotation mechanism. Therefore, it is easy to mount the transceiver device on the rotation mechanism. [Brief explanation of the drawings]

[0011] [Figure 1]A diagram showing an example of a radar with one antenna mounted on a rotating mechanism. [Figure 2] A diagram showing an example of a radar with four antennas mounted on a rotating mechanism. [Figure 3] FIG. 10 is a diagram showing an example of a radar having a plurality of combinations of antenna devices and transmitting / receiving devices. [Figure 4] FIG. 1 is a diagram showing an example of the configuration of a radar system according to the present invention. [Figure 5] FIG. 1 is a diagram showing a configuration example of an antenna device according to a first embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of the configuration of a transmitting / receiving device according to the first embodiment. [Figure 7] FIG. 1 is a diagram for explaining an outline of a radar system according to a first embodiment. [Figure 8] FIG. 10 is a diagram showing a configuration example of a transmitting / receiving device according to a first modification of the first embodiment. [Figure 9] FIG. 10 is a diagram showing a configuration example of a transmitting / receiving device according to a second modification of the first embodiment. [Figure 10] FIG. 10 is a diagram showing a configuration example of an antenna device according to a second embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of the configuration of a transmitting / receiving device according to a second embodiment. [Figure 12] FIG. 10 is a diagram showing a configuration example of an antenna device according to a third embodiment. [Figure 13] FIG. 10 is a diagram showing an example of the configuration of a transmitting / receiving device according to a third embodiment. [Figure 14] FIG. 10 is a diagram showing an example of a control signal transmission method according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described in detail. Components having the same functions will be assigned the same numbers, and duplicate explanations will be omitted. In the following description, N is an integer of 2 or more, and n is an integer of 1 to N. [Example]

[0013] FIG. 4 shows a configuration example of a radar system according to the first embodiment. FIG. 5 shows a configuration example of an antenna device according to the first embodiment, and FIG. 6 shows a configuration example of a transmitting / receiving device according to the first embodiment. FIG. 7 is a diagram for explaining the outline of the radar system according to the first embodiment. The radar system includes N antenna devices 1001, ..., 100 N , a divider / combiner 300, and a transmitting / receiving device 200. N antenna devices 1001, ..., 100 N The divider / combiner 300 is connected to N antenna devices 1001, ..., 100 N The antenna devices 1001, ..., 100 are arranged on the rotation mechanism 950 so that their directivity angles do not overlap. The distributor / combiner 300 and the transmitter / receiver 200 are connected via a rotary joint 440. The rotary joint 440 is assumed to be a single-core coaxial type that is widely used for transmitting RF signals. The rotation mechanism 950 rotates the N antenna devices 1001, ..., 100 N and rotate the distributor-combiner 300 horizontally.

[0014] Antenna device 100 n Antenna 110 n , transmission / reception discriminator 120 n , frequency conversion unit 140 n , antenna frequency discriminator 130 n The transmitting / receiving device 200 includes a clock oscillator 240, a transmitting section 210, a transmitting / receiving frequency discriminator 220, an A / D converting section 230, a receiving channel discriminator 250, and a power supply section 260.

[0015] Antenna 110 n Assume that the antenna is the same as that of a conventional radar. For example, an array antenna with its longitudinal direction oriented horizontally can be used. If the array antenna has its longitudinal direction oriented horizontally, it can produce a fan beam pattern with directivity that is narrow in the horizontal direction and relatively wide in the vertical direction. Therefore, the antenna devices 1001, ..., 100 N It is easy to arrange them on the rotation mechanism 950 so that their directivity angles do not overlap.

[0016] Transmitting / receiving discriminator 120 n is an antenna frequency discriminator 130 nThe transmitted RF signal from the antenna 110 n and outputs to antenna 110 n The received RF signal is converted into a frequency by the frequency converter 140. n Output to.

[0017] Frequency conversion unit 140 n transmits the received RF signal to the antenna 110 n The antenna frequency discriminator 130 converts the received IF signals into different frequencies. n The frequency conversion unit 140 outputs the n frequency converter 141 n , local oscillator 142 n , reference oscillator 143 n , voltage regulator 144 n , controller 145 n The frequency converter 141 may be provided. n is the received RF signal and the local oscillator 142 n The frequency converter 141 multiplies the received IF signal by a local oscillation signal input from the n The local oscillator 142 includes RF and IF amplifiers, band limiting filters, etc. n is the reference oscillator 143 n Based on the reference signal from the controller 145 n The local oscillation signal is converted into a frequency converter 141 according to the control of the n Reference oscillator 143 n is a constant voltage regulator 144 n A predetermined reference signal is generated by a local oscillator 142. n The controller 145 outputs the n It has built-in software and a constant voltage regulator 144 n When DC power is input from the local oscillator 142, a predetermined control signal is generated spontaneously. n The predetermined control signal is, for example, a signal from the local oscillator 142. n is the frequency of the local oscillation signal output by the voltage regulator 144. n is an antenna frequency discriminator 130 n The DC power supplied from the frequency converter 141 n , local oscillator 142 n, reference oscillator 143 n , controller 145 n When all the required power supply voltages are equal, the constant voltage generator 144 n The frequency of the local oscillation signal may be omitted. N The N received IF signals have different frequencies. n This allows the received signal from to be distinguished by frequency.

[0018] Antenna Frequency Discriminator 130 n The transmit RF signal from the distributor / synthesizer 300 is divided into a transmit / receive discriminator 120 n and the frequency conversion unit 140 n The received IF signal from the antenna frequency discriminator 130 is output to the divider / combiner 300. n The DC power from the divider / combiner 300 is converted into a frequency by the frequency converter 140. n Voltage regulator 144 n Antenna frequency discriminator 130 n The antenna frequency discriminator 130 may be configured with, for example, an RF high-pass filter, an IF band-pass filter, and a DC-pass inductor. n This allows the signal line between the power supply and the distributor / combiner 300 to be one (=one core), and enables RF, IF, and DC power to be superimposed and transmitted.

[0019] The divider / combiner 300 divides the transmission RF signal from the transmission / reception frequency discriminator 220 into N signals, and outputs the N signals to the antenna frequency discriminators 1301, ..., 1302. N and outputs N antenna frequency discriminators 1301, ..., 130 N The divider / combiner 300 outputs a combined receive IF signal, which is a signal obtained by combining receive IF signals from the transmitter and receiver, to the transmit / receive frequency discriminator 220. The divider / combiner 300 divides the signal into N frequencies ranging from DC to RF signals. A resistive divider / combiner may be used as the divider / combiner 300, for example.

[0020] The clock oscillator 240 generates a clock signal for processing within the transceiver 200. The clock oscillator 240 generates a clock signal with a frequency at least twice the maximum frequency of the N received IF signals, and outputs the clock signal to the A / D converter 230. If the transmitter 210 is a solid-state radar having a semiconductor amplifier, the clock signal is also output to the transmitter 210.

[0021] The transmitter 210 outputs a transmission RF signal to the transmission / reception frequency discriminator 220. The transmitter 210 is the same as the transmitter of a conventional transceiver, and generates a transmission RF signal and outputs it to the transmission / reception frequency discriminator 220.

[0022] The transmission / reception frequency discriminator 220 outputs the transmission RF signal from the transmitter 210 to the divider / combiner 300, and outputs the combined reception IF signal from the divider / combiner 300 to the A / D converter 230. The transmission / reception frequency discriminator 220 is connected to the antenna frequency discriminator 130. n It has the same function as

[0023] The A / D conversion unit 230 converts the combined received IF signal into a combined digital IF signal and outputs it to the received channel discriminator 250. The A / D conversion unit 230 operates with a clock signal having a frequency at least twice the maximum frequency of the N received IF signals.

[0024] The receive channel discriminator 250 transmits the composite digital IF signal to the antenna device 100. n The reception channel discriminator 250 has N bandpass filters corresponding to the frequencies of the N reception IF signals, and transmits the composite digital IF signal to the N antenna devices 1001, ..., 1002. N The signal is divided into signals corresponding to the

[0025] In the power supply unit 260, N antenna devices 1001, ..., 100 N and transmits the power to each antenna device 100 via a transmission / reception frequency discriminator 220, a rotary joint 440, and a distributor / combiner 300. n supplies power to

[0026] Next, with reference to Fig. 7, the operation when the number of antenna devices is two will be specifically described. Fig. 7 shows a specific example of antenna frequency discriminators 1301, 1302 and transmission / reception frequency discriminator 220. The transmission RF signal generated by transmitter 210 is output to divider / combiner 300 via transmission / reception frequency discriminator 220 and rotary joint 440. The frequency of the transmission RF signal at this time is 9410 MHz. Divider / combiner 300 divides the transmission RF signal into two and outputs transmission RF signals of equal levels to two antenna devices 1001, 1002. Antenna device 100 n The transmitted RF signal input to the antenna frequency discriminator 130 n , transmission / reception discriminator 120 n via Antenna 110 n The signal is radiated into space from the antenna 110. n The signal emitted from the antenna 110 and reflected by surrounding objects is transmitted to the antenna 110 as a received RF signal. n and the signal is input to the transmission / reception discriminator 120 n via the frequency conversion unit 140 n The frequency conversion unit 140 n The received RF signal is frequency converted to a received IF signal by the local oscillator 142. n By slightly changing the frequency of the local oscillation signal output from the two antenna devices 1001 and 1002, n For example, the frequencies of the received IF signals are set to 30 MHz and 50 MHz, respectively. n The received IF signal output from the antenna frequency discriminator 130 nThe received IF signal is output to the A / D converter 230 via the distributor / synthesizer 300, rotary joint 440, and transmission / reception frequency discriminator 220. If the frequency of the clock signal from the clock oscillator 240 is 150 MHz, the Nyquist frequency is 75 MHz, and a combined reception IF signal having two different frequencies can be received. The A / D converter 230 converts the combined reception IF signal into a combined digital IF signal, and if the digital IF signals are input to 30 MHz and 50 MHz bandpass filters in the reception channel discriminator 250, the received signals from the two antenna devices 1001 and 1002 can be processed separately, and measurement results for the two antenna devices 1001 and 1002 can be obtained simultaneously.

[0027] According to the radar system of the first embodiment, the antenna devices 1001, . . . , 100 N The received IF signals sent from the antennas to the transceiver device 200 have different frequencies for each antenna. n Since there is no need to provide a separate device for each radar system, there is no need to mount the transmitting / receiving device 200 on the rotation mechanism 950. Therefore, the radar system of the first embodiment can be easily mounted on the rotation mechanism 950. [Variation 1]

[0028] 8 shows an example of the configuration of a transmission / reception device according to Modification 1 of the first embodiment. The transmission / reception device 201 includes a clock oscillator 240, a transmission unit 210, a transmission / reception frequency discriminator 221, A / D conversion units 2311, ..., 231 N , and a power supply unit 260. The transmission / reception frequency discriminator 221 divides the combined reception IF signal into N antenna frequency discriminators 1301, ..., 130 N The N received IF signals discriminated into the received IF signals from the corresponding A / D converters 2311, ..., 231 N The A / D converter 231 outputs the signal. n The antenna device 100 n The other aspects are the same as in the first embodiment. [Variation 2]

[0029] 9 shows an example of the configuration of a transmission / reception device according to the second modification of the first embodiment. The transmission / reception device 202 includes a clock oscillator 240, a transmitter 210, a transmission / reception frequency discriminator 221, an IF switch 280, an A / D converter 230, and a power supply 260. The transmission / reception frequency discriminator 221 divides the combined reception IF signal into N antenna frequency discriminators 1301, ..., 1302. N The N received IF signals discriminated from the received IF signals are output to the IF switch 280. The IF switch 280 selects one received IF signal from the N received IF signals and outputs it to the A / D conversion unit 230. The A / D conversion unit 230 converts the input received IF signal into a digital IF signal. The rest is the same as in the first embodiment.

[0030] 8 and 9, it is also possible to reduce the clock signal frequency by appropriately selecting the frequency of the received IF signal. For example, if one of the received IF signals is kept at 30 MHz and the other is 125 MHz, and the former is oversampled and the latter is undersampled, the clock signal frequency can be reduced to 75 MHz. In addition, using undersampling is also useful for adding frequencies to the received IF signal, i.e., increasing the number N of antenna devices to be measured simultaneously. For example, if the clock signal frequency is 150 MHz, the received IF frequencies can be set to 30 MHz and 50 MHz, or 180 MHz and 200 MHz, with the first two frequencies oversampled and the last two undersampled. [Example]

[0031] FIG. 4 shows a configuration example of a radar system according to the second embodiment. FIG. 10 shows a configuration example of an antenna device according to the second embodiment, and FIG. 11 shows a configuration example of a transmitting / receiving device according to the second embodiment. The radar system includes N antenna devices 1031, ..., 103 N The antennas 1031, ..., 103 are N antenna devices. N The divider / combiner 300 is connected to N antenna devices 1031, ..., 103 NThe antenna devices 1031, ..., 103 are arranged on the rotation mechanism 950 so that their directivity angles do not overlap. The distributor / combiner 300 and the transmitter / receiver 203 are connected via a rotary joint 440. The rotary joint 440 is assumed to be a single-core coaxial type that is widely used for transmitting RF signals. The rotation mechanism 950 is N and rotate the distributor-combiner 300 horizontally.

[0032] Antenna device 103 n Antenna 110 n , transmission / reception discriminator 120 n , frequency conversion unit 150 n , antenna frequency discriminator 133 n The transmitting / receiving device 203 includes a clock oscillator 240, a transmitting unit 210, a transmitting / receiving frequency discriminator 223, an A / D conversion unit 230, a receiving channel discriminator 250, a power supply unit 260, and a reference oscillator 243. n , transmission / reception discriminator 120 n , clock oscillator 240, transmitting section 210, A / D conversion section 230, receiving channel discriminator 250, and power supply section 260 are the same as those in the first embodiment.

[0033] The reference oscillator 243 is disposed in the transmitting / receiving device 203 and generates a reference signal. The transmitting / receiving frequency discriminator 223 outputs the reference signal from the reference oscillator 243 together with the transmission RF signal from the transmitting unit 210 to the antenna devices 1031, ..., 103. N Antenna frequency discriminator 133 n The transmit RF signal from the distributor / synthesizer 300 is divided into a transmit / receive discriminator 120 n and the frequency conversion unit 150 n The received IF signal from the antenna frequency discriminator 133 is output to the divider / combiner 300. n The DC power from the divider / combiner 300 is converted into a frequency power by the frequency converter 150. n Voltage regulator 144 n Supply to.

[0034] Frequency conversion unit 150 n frequency converter 141 n, local oscillator 152 n , voltage regulator 144 n , controller 145 n The local oscillator 152 n is generated by the controller 145 based on the reference signal from the reference oscillator 243. n The local oscillation signal is converted into a frequency converter 141 according to the control of the n The frequency converter 141 outputs n , voltage regulator 144 n , controller 145 n is the same as in the first embodiment.

[0035] Modifications 1 and 2 of the first embodiment can also be applied to the second embodiment. In the case of the radar system of the second embodiment, the same effects as those of the radar system of the first embodiment can be obtained. [Example]

[0036] FIG. 4 shows a configuration example of a radar system according to the third embodiment. FIG. 12 shows a configuration example of an antenna device according to the third embodiment, and FIG. 13 shows a configuration example of a transmitting / receiving device according to the third embodiment. The radar system includes N antenna devices 1041, ..., 104 N The antennas 1041, ..., 104 are N antenna units. N The divider / combiner 300 is connected to N antenna devices 1041, ..., 104 N The antennas 1041, ..., 104 are arranged on the rotation mechanism 950 so that their directivity angles do not overlap. The distributor / combiner 300 and the transmitter / receiver 204 are connected via a rotary joint 440. The rotary joint 440 is assumed to be a single-core coaxial type that is widely used for transmitting RF signals. The rotation mechanism 950 is N and rotate the distributor-combiner 300 horizontally.

[0037] Antenna device 104 n Antenna 110 n , transmission / reception discriminator 120 n , frequency conversion unit 160 n , antenna frequency discriminator 134 n , switch 180 nThe transmitting / receiving device 204 includes a clock oscillator 240, a transmitting unit 210, a transmitting / receiving frequency discriminator 224, an A / D conversion unit 230, a receiving channel discriminator 250, a power supply unit 260, a reference oscillator 243, a control modulator 265, and an antenna device control unit 270. n , transmission / reception discriminator 120 n The clock oscillator 240, the transmitter 210, the A / D converter 230, the receiving channel discriminator 250, and the power supply 260 are the same as those in the first embodiment. The reference oscillator 243 is the same as that in the second embodiment.

[0038] The transmission / reception frequency discriminator 224 receives the transmission RF signal from the transmitter 210, the reference signal from the reference oscillator 243, and the signal from the switch 180. n The signals controlling the antenna devices 1041, ..., 104 N Antenna frequency discriminator 134 n The transmit RF signal from the distributor / synthesizer 300 is divided into a transmit / receive discriminator 120 n and the frequency conversion unit 160 n The received IF signal from the antenna frequency discriminator 134 is output to the divider / combiner 300. n The DC power from the divider / combiner 300 is converted into a frequency by the frequency converter 160. n Voltage regulator 144 n Supply to.

[0039] Frequency conversion unit 160 n frequency converter 141 n , local oscillator 152 n , voltage regulator 144 n , control demodulator 165 n The local oscillator 152 n is the same as in the second embodiment. n , voltage regulator 144 n is the same as in the first embodiment.

[0040] Switch 180 n is the frequency conversion unit 160 n The antenna device control unit 270 switches the switch 180 to the receiving RF signal at the timing when the transmitting RF signal is output. nis the frequency conversion unit 160 n The control signal from the antenna device control section 270 is modulated by the control modulator 265 and transmitted to the control demodulator 165. n It is demodulated by the switch 180 n Control.

[0041] FIG. 14 shows an example of a control signal transmission method. In FIG. 14, it is assumed that antenna device control section 270 outputs three-bit control signals A, B, and C. Control modulator 265 multiplies each of control signals A to C by a different coefficient and combines them to generate a control modulation signal. In FIG. 14, A to C are converted to (1V, 0V), (2V, 0V), and (4V, 0V), respectively, and then these are combined. The control modulation signal is a signal having three bits of information in the magnitude of the level. The control modulation signal output from control modulator 265 is further superimposed with a DC power component output from power supply section 260 by transmission / reception frequency discriminator 224 to generate the control modulation signal for antenna device 104. n In FIG. 14, the DC power supply voltage is set to 5V. n Antenna frequency discriminator 134 n Then, the DC power supply component is removed from the transmitted signal, and the control modulation signal is sent to the control demodulator 165. n Control demodulator 165 n The control unit 204 reads 3-bit information from the level of the control demodulation signal, generates a control signal, and outputs the control signal. Note that by consolidating the antenna device control unit 270 in the transmission / reception device 204, the frequency conversion unit 160 n Switch 180 that cuts off the RF input of n For each transmission, the antenna device 104 n This has the advantage that it can be easily controlled.

[0042] The first and second modifications of the first embodiment can also be applied to the third embodiment. The radar system of the third embodiment can also obtain the same effects as the radar system of the first embodiment. In the third embodiment, the switch 180 n is the frequency conversion unit 160 nThe advantage of having the antenna device control unit 270 in the transceiver device 204 is that the antenna device 104 n Switch 180 inside n However, the antenna device control unit 270 controls the antenna device 104 n The advantage of being able to control the timing may be utilized for other processing. The antenna device control unit 270 can perform control in accordance with the timing of processing within the transmission / reception device 204. [Explanation of symbols]

[0043] 100 n ,103 n ,104 n ,910 n Antenna device 110 n Antenna 120 n Transmitting and receiving discriminator 130 n ,133 n ,134 n Antenna Frequency Discriminator 140 n ,150 n ,160 n Frequency conversion section 141 n Frequency converter 142 n ,152 n Local Oscillator 143 n ,243 Reference oscillator 144 n Voltage regulator 145 n Controller 165 n Control Demodulator 180 n Switch 200,201,202,203,204,930 n Transmitting and receiving device 210 Transmitter 220, 221, 223, 224 Transmit / receive frequency discriminator 230,231 n A / D converter 240 Clock oscillator 250 receiving channel discriminator 260 power supply unit 265 Control modulator 270 Antenna device control unit 280 IF switch 300 Distributor / combiner 440,940 Rotary joint 950 Rotation mechanism

Claims

1. A radar system having N antenna devices, a divider / combiner, and a transmitter / receiver, N is an integer of 2 or more, the N antenna devices and the divider / combiner are arranged on a rotation mechanism so that the directivity angles of the N antenna devices do not overlap with each other; the antenna device includes an antenna, a transmission / reception discriminator, a frequency conversion unit, and an antenna frequency discriminator; the transmitting / receiving device includes a clock oscillator, a transmitting unit, a transmitting / receiving frequency discriminator, and an A / D converter; the transmission / reception discriminator outputs a transmission RF signal from the antenna frequency discriminator to the antenna, and outputs a reception RF signal from the antenna to the frequency conversion unit; the frequency conversion unit converts the received RF signal into a received IF signal having a different frequency for each antenna, and outputs the converted IF signal to the antenna frequency discriminator; the antenna frequency discriminator outputs a transmission RF signal from the divider / combiner to the transmission / reception discriminator, and outputs a reception IF signal from the frequency conversion unit to the divider / combiner; the divider / combiner divides the transmission RF signal from the transmission / reception frequency discriminator into N signals and outputs the N signals to the antenna frequency discriminators, and outputs a composite reception IF signal, which is a signal obtained by combining the reception IF signals from the N antenna frequency discriminators, to the transmission / reception frequency discriminator; the clock oscillator generates a clock signal for processing within the transceiver; the transmitter outputs a transmission RF signal to the transmission / reception frequency discriminator; the transmission / reception frequency discriminator outputs a transmission RF signal from the transmitter to the divider / combiner, and outputs a composite reception IF signal from the divider / combiner or N reception IF signals obtained by discriminating the composite reception IF signal into N reception IF signals from the antenna frequency discriminators to the A / D converter; The A / D converter converts the signal from the transmission / reception frequency discriminator into a digital signal. A radar system characterized by:

2. 10. The radar system of claim 1, the transceiver also includes a receive channel discriminator; The transmission / reception frequency discriminator outputs the composite reception IF signal to the A / D conversion unit, the A / D converter converts the composite received IF signal into a composite digital IF signal; The receive channel discriminator divides the composite digital IF signal into digital IF signals for each of the antenna units. A radar system characterized by:

3. 10. The radar system of claim 1, the transmitting / receiving device includes N A / D conversion units, the transmitting / receiving frequency discriminator discriminates the composite receiving IF signal into N receiving IF signals from the antenna frequency discriminators, and outputs the N receiving IF signals to the corresponding A / D conversion units; The N A / D converters output digital IF signals for each of the antenna devices. A radar system characterized by:

4. 10. The radar system of claim 1, The transceiver also includes an IF switch; the transmitting / receiving frequency discriminator discriminates the composite receiving IF signal into N receiving IF signals from the antenna frequency discriminators, and outputs the N receiving IF signals to the IF switch; the IF switch selects one received IF signal from the N received IF signals and outputs the selected IF signal to the A / D conversion unit; The A / D converter converts the input received IF signal into a digital IF signal. A radar system characterized by:

5. A radar system according to any one of claims 1 to 4, The transceiver also includes a reference oscillator; The frequency conversion unit generates a signal for converting a received RF signal into a received IF signal from the signal generated by the reference oscillator. A radar system characterized by:

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