JP2019164016A - Radar device and object detection method for radar device - Google Patents

Abstract

To reduce an influence of convergence of a signal from a transmission circuit to a reception circuit by a simple circuit configuration.SOLUTION: The device includes: transmitting antennas 12-1 to 12-2 of one or more series and receiving antennas 14-1 to 14-4 of one or more series which constitute a plurality of transceiver series; frequency conversion means (MMIC11) for carrying out frequency conversion of a reception signal to a lower frequency while carrying out input and output of the transmitting signal and reception signal to the transmitting antenna and the receiving antenna; estimation means (signal processing unit 17) for estimating a direction of a subject based on information including a phase contrast of the transceiver series signal to which frequency conversion has been carried out; first adjustment means (phase adjustment units 17-2 to 17-8) for adjusting a phase of the transceiver series signal on the lower frequency side than the frequency conversion means; and second adjustment means (phase adjustment units 13-2 to 17-5) for adjusting the phase of the transceiver series signal on the higher frequency side than the frequency conversion means to cancel the phase adjustment by the first adjustment means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radar apparatus and an object detection method for the radar apparatus.

  In recent years, a radar apparatus that can detect an object (for example, another vehicle, a pedestrian, an obstacle, etc.) existing around a vehicle has come to be frequently used.

  In such a radar apparatus, the electromagnetic wave transmitted from the transmission unit via the transmission antenna is reflected by the object and received by the reception unit via the reception antenna. However, the signal may sneak directly from the transmitter to the receiver. In such a case, the signal that wraps around becomes noise, which makes it difficult to detect an object existing at a close distance.

  Therefore, Patent Document 1 discloses a short-range pulse radar device that enables measurement of a close range as close as possible to 0 m while suppressing the influence of an interference wave due to transmission. In this configuration, a method is adopted in which the high-frequency circuit is configured discretely, and the wraparound of the transmission signal wave to the receiving unit is reduced by circuit configuration or phase adjustment.

  Patent Document 2 discloses a radar configuration using MMIC as well as a discrete circuit configuration. In this example, in the configuration in which the MMIC in the transmission unit and the MMIC in the reception unit are installed separately, the choke structure is provided in the shield unit to solve the problem of going around the space from the transmission unit to the reception unit. The suppression is aimed at.

  Further, in Patent Document 3, a signal sneaking from a transmitting unit existing inside a radar to a receiving unit as described above is transferred to an unnecessary signal from a part of a vehicle body such as a bumper that is not a desired target signal of a radar. A technique has been shown that cancels unnecessary wraparound by canceling each other by controlling the phase with a phase shifter.

  Further, Patent Document 4 discloses a technique for performing phase control using a phase shifter for each transmission antenna sequence in order to reduce the reception level outside the main transmission time of the radar. Thus, the phase state outside the main transmission time is set to a state different from the desired phase state at the main transmission time, and the level outside the main transmission time is reduced by controlling the radiation pattern of the transmission antenna.

JP 2017-198447 A JP 2014-093446 A JP2015-102458A JP 2010-197232 A

  However, the technique disclosed in Patent Document 1 is intended to reduce the wraparound by the discrete circuit itself, and is not integrated or miniaturized as a circuit. Further, this is an example in which each of the transmission sequence and the reception sequence has only one sequence, and does not intend to reduce the wraparound in the case of having a plurality of transmission / reception systems.

  In the technique disclosed in Patent Document 2, the transmission unit and the reception unit are independent MMICs. In the case of an MMIC in which transmission and reception are integrated, there is a problem that it cannot be sufficiently reduced in a situation where wraparound inside the MMIC is likely to occur compared to wraparound due to a space outside the MMIC.

  Further, the technique disclosed in Patent Document 3 requires a phase shifter that can be set to an arbitrary phase in order to cope with an external factor of the radar apparatus, so that the apparatus becomes expensive.

  Furthermore, in the technique shown in Patent Document 4, phase control is performed for each transmission antenna sequence. However, since the control is based on a phase shifter that changes with time, the radar apparatus is expensive and large. There is a problem that becomes. In addition, there is a problem that it cannot be applied in a situation where a sneak signal and a desired signal are received simultaneously.

  An object of the present invention is to provide a radar apparatus and an object detection method for a radar apparatus that can reduce the influence of a signal wraparound from a transmission circuit to a reception circuit with a simple circuit configuration.

In order to solve the above problems, the present invention provides a radar apparatus for detecting an object, wherein one or more transmission antennas and one or more reception antennas constituting a plurality of transmission / reception sequences, the transmission antennas and the reception antennas are provided. In contrast, the input / output of the transmission signal and the reception signal and frequency conversion means for frequency conversion of the reception signal to a lower frequency, and information including the phase difference between the transmission / reception sequence signals frequency-converted by the frequency conversion means Based on the estimation means for estimating the orientation of the object, first adjustment means for adjusting the phase of the transmission / reception sequence signal on the lower frequency side than the frequency conversion means, and on the higher frequency side than the frequency conversion means, And second adjusting means for adjusting the phase of the transmission / reception sequence signal so as to cancel the phase adjustment by the first adjusting means. It is characterized in.
According to such a configuration, it is possible to detect a desired signal by separating the influence of the signal wraparound from the transmission circuit to the reception circuit by the azimuth axis with a simple circuit configuration.

Further, in the present invention, the frequency conversion unit is configured as an integrated circuit having a transmission unit that outputs the transmission signal to the transmission antenna, and a reception unit that receives the reception signal from the reception antenna. It is characterized by that.
According to such a configuration, it is possible to reduce the size and reduce the sneak signal.

In the invention, it is preferable that the second adjustment unit adjusts the phase by changing at least two of the transmission line lengths between the frequency conversion unit and the transmission antenna or the reception antenna. Features.
According to such a configuration, the influence on the reflected signal from the object by the first adjusting means is achieved by the circuit configuration that is easy to adjust the phase by slightly adjusting the path length of the line, which is a characteristic of the high frequency region. Can be reduced.

Further, the present invention is characterized in that the first adjusting means adjusts the phase by performing digital signal processing on the transmission / reception sequence signal.
According to such a configuration, desired characteristics can be easily realized without any additional components in a low-frequency region where adjustment with a slight line length is impossible.

In the present invention, the frequency conversion unit includes a transmission unit that outputs the transmission signal to the transmission antenna, and a reception unit that receives the reception signal from the reception antenna, and the first adjustment unit. Is characterized in that the sneak signal is moved outside the detection angle range for detecting the azimuth by adjusting the phase of the sneak signal that wraps around from the transmitter to the receiver.
According to such a configuration, the sneak signal can be moved outside the detection angle range by adjusting the phase, the sneak signal within the detection angle range can be reduced, and the strength of the desired signal can be relatively ensured. Is possible.

In the present invention, when the wavelength of the received signal is λ, the adjacent set of transmitting antennas of the transmitting antennas or the adjacent set of transmitting antennas of the receiving antennas Are arranged at intervals of λ / 2, and the second adjustment means has an approximately opposite phase with respect to the transmission signal or the reception signal corresponding to at least one pair of the transmission antennas or the reception antennas adjacent to each other. The phase adjustment is performed.
According to such a configuration, the sneak signal is effectively moved out of the detection range in the case where the sneak phases of adjacent sequences are substantially in phase and the antenna arrangement is a practical λ / 2 interval for angle detection. It becomes possible.

Further, the present invention is characterized in that transmission sequences of sneak signals from the transmission unit to the reception unit of the integrated circuit or reception sequences are set to be substantially in phase.
According to such a configuration, the number of wraparound combinations can be reduced in a situation where adjustment parameters are insufficient in comparison with the number of wraparound combinations in principle, and the influence of wraparound can be reliably reduced.

Further, the present invention provides a transmission path connecting the integrated circuit and the transmitting antenna or a transmission path connecting the integrated circuit and the receiving antenna with respect to a line segment passing through the center of the integrated circuit. It is characterized by being arranged symmetrically.
According to such a structure, the influence by environmental changes, such as temperature and humidity, can be reduced.

In the invention, it is preferable that the first adjustment unit adjusts the phase so that a peak of a sneak signal from the transmission unit to the reception unit is an angle of 45 degrees or more from the center of the detection range. And
According to such a configuration, it is possible to ensure detection of more than half of the detection range.

In the present invention, the integrated circuit has a polygonal shape, and has a plurality of ports to which a plurality of transmission lines are connected along the side of the polygonal shape, and connects the integrated circuit and the transmitting antenna. And the transmission line connecting the integrated circuit and the receiving antenna are connected to ports along different sides.
According to such a configuration, a sneak signal from the transmitting antenna to the receiving antenna can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the radar apparatus and the target object detection method of a radar apparatus which can reduce the influence by the wraparound of the signal from a transmission circuit to a receiving circuit with a simple circuit structure.

It is a figure which shows the structural example of the radar apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the conventional radar apparatus. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. 3 is a configuration example in which a phase adjustment unit is added to the radar apparatus shown in FIG. 2. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a figure which shows other embodiment of this invention. It is a figure which shows the specific structural example of MMIC.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of Embodiment of the Present Invention FIG. 1 is a diagram illustrating a configuration example of a radar apparatus according to an embodiment of the present invention. As shown in this figure, a radar apparatus 10 according to an embodiment of the present invention is mounted on a vehicle such as an automobile, and detects objects such as other vehicles, pedestrians, and obstacles existing around the vehicle. To do.

  Here, the radar apparatus 10 includes a MMIC (Monolithic Microwave Integrated Circuit) 11, transmission antennas 12-1 to 12-2, phase adjustment units 13-2, 13-4, and 13-5, and reception antennas 14-1 to 14-. 4, an amplifier circuit 15, an A / D (Analog to Digital) converter 16, and a signal processor 17. Note that the configuration of the embodiment illustrated in FIG. 1 is merely an example, and may be an arbitrary functional block. For example, in the embodiment of FIG. 1, the MMIC 11, the amplifier circuit 15, and the A / D converter 16 are configured independently, but at least one of the amplifier circuit and the A / D converter 16 is built in the MMIC 11. It is good also as a structure. Further, the amplifier circuit 15 is not necessarily required, and an arbitrary functional block such as a filter may be provided. In the example of FIG. 1, phase adjustment units 13-2, 13-4, and 13-5 are provided in the transmission antenna 12-2 and the reception antennas 14-2 and 14-3, and the signal processing unit 17 transmits and receives the transmission / reception sequence Tx1Rx2. , Tx1Rx3, Tx2Rx1, and Tx2Rx4 are provided with phase adjustment units 17-2, 17-3, 17-5, and 17-8, but these are examples, and may be provided in a combination other than these.

  Here, the MMIC 11 is configured by a semiconductor integrated circuit. For example, in the transmission unit, a high-frequency signal is generated by an operation of a control signal, a high-frequency oscillator, and the like, is output from the transmission port, and transmitted from the transmission antennas 12-1 to 12-2. Send. In addition, high-frequency signals are transmitted from the transmission antennas 12-1 to 12-2, the reflected waves reflected by the object are received via the reception antennas 14-1 to 14-4, and input from the reception port in the reception unit. The high frequency signal is subjected to processing such as low noise amplification, and then converted to a low frequency signal and output.

  The transmission antennas 12-1 to 12-2 transmit a high-frequency signal supplied from the MMIC 11 toward an object as an electromagnetic wave. The receiving antennas 14-1 to 14-4 receive the reflected waves transmitted from the transmitting antennas 12-1 to 12-2 and reflected by the object, convert them into electric signals, and supply them to the MMIC 11. When the wavelength of the received signal is λ, the receiving antennas 14-1 to 14-4 are arranged at an interval of approximately λ / 2 from the viewpoint of suppressing the grating lobe. The transmission antennas 12-1 to 12-2 are arranged on both sides of the four reception antennas 14-1 to 14-4, or on the lower side or the upper side.

  The phase adjustment units 13-2, 13-4, and 13-5 adjust the phase of the high-frequency signal transmitted through the transmission antenna 12-2 and the reception antennas 14-2 and 14-3 and output the result.

  The amplifying circuit 15 receives a signal converted into a low frequency signal by frequency conversion by the MMIC 11, amplifies the signal with a predetermined gain, and outputs the amplified signal.

  The A / D converter 16 samples the analog signal output from the amplifier circuit 15 at a predetermined sampling period, converts it to a digital signal, and outputs it.

  The signal processing unit 17 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), or an FPGA (Field Programmable Gate Array). The signal processing unit 17 performs digital processing such as FFT (Fast Fourier Transform) processing, object detection processing, clustering processing, and tracking processing on the digital signal supplied from the A / D conversion unit 16. Then, for example, an ECU (Electric Control Unit) that is a higher-level processing device is notified of information about the obtained object.

(B) Description of Operation of Embodiment Next, the operation of the embodiment of the present invention will be described. Hereinafter, the operation principle of the embodiment of the present invention will be described with reference to FIGS. 2 to 5 and then the detailed operation will be described.

  2 does not include the characteristic portions of the present embodiment (phase adjusting units 13-2, 13-4, 13-5 and phase adjusting units 17-2, 17-3, 17-5, 17-8). It is a figure which shows the example of a structure. In the configuration shown in FIG. 2, for example, a sneak path of a transmission signal from the transmission unit built in the MMIC 11 to the reception unit (hereinafter referred to as “around signal”) occurs inside and around the MMIC 11. In FIG. 2, the sneak signal from the transmission unit to the reception unit is indicated by a thick arrow.

  When such a sneak signal is generated, the MMIC 11 converts the frequency of the sneak signal as a high frequency signal and outputs it as a low frequency signal. Note that high-frequency signals transmitted from the transmitting antennas 12-1 to 12-2, reflected by the object, and received by the receiving antennas 14-1 to 14-4 are similarly converted into low-frequency signals and output. .

  The signal output from the MMIC 11 is amplified with a predetermined gain by the amplifier circuit 15, converted into a digital signal by the A / D converter 16, and supplied to the signal processor 17.

  The signal processing unit 17 executes processing for detecting an object based on the digital signal supplied from the A / D conversion unit 16. Here, in the example shown in FIG. 1 and FIG. 2, it has two transmitting antennas 12-1 to 12-2 and four receiving antennas 14-1 to 14-4. The MMIC 11 sequentially transmits electromagnetic waves from the two transmission antennas 12-1 to 12-2 and sequentially receives them by the four reception antennas 14-1 to 14-4. By combining such transmission antennas 12-1 to 12-2 and reception antennas 14-1 to 14-4, eight transmission / reception sequences Tx1Rx1, Tx1Rx2, Tx1Rx3, Tx1Rx4, Tx2Rx1, Tx2Rx2, Tx2Rx3, and Tx2Rx4 are formed. . The radar apparatus 10 detects an angle (azimuth) at which an object exists by processing information including a phase difference of a signal obtained by such a transmission / reception sequence (hereinafter referred to as a “transmission / reception sequence signal”). Can do.

  Based on the digital signal supplied from the A / D conversion unit 16, the signal processing unit 17 performs processing such as calculating angle characteristics from information including a phase difference between transmission and reception sequence signals. Are processed in the same manner as the transmission / reception sequence signal from the object. Such a wraparound signal acts as noise on the signal from the object.

  FIG. 3 is a diagram showing angle characteristics when the wraparound shown in FIG. 2 occurs. In FIG. 3, the horizontal axis indicates the angle (deg), and the vertical axis indicates the amplitude (au (arbitrary unit)) detected by the radar. FIG. 3 shows a case where an object is present at a position of +20 deg ahead of the radar apparatus 10. Moreover, the case where it is the transmission / reception series shown to the following formula | equation (1) as a roundabout signal is assumed. [] Within the equal sign indicates the phase of each sneak signal. Although the present embodiment exemplifies FFT processing for angle detection, it can also be applied to other processing such as the MUSIC method.

[Tx1Rx1, Tx1Rx2, Tx1Rx3, Tx1Rx4, Tx2Rx1, Tx2Rx2, Tx2Rx3, Tx2Rx4]
= [0deg, 0deg, 180deg, 180deg, 180deg, 180deg, 0deg, 0deg] (1)

  In FIG. 3, the solid line shows ideal characteristics when no wraparound signal exists, and a peak corresponding to the object exists at a position of +20 deg. The broken line indicates the characteristics of the sneak signal. A peak exists not only at the position of +20 deg but also at the position of -20 deg, and small peaks also exist at the positions of +40 deg and -40 deg. In the example of FIG. 3, the sneak signal has a larger amplitude than the signal from the object. For this reason, when there is a sneak signal, erroneous detection may occur or the target may not be detected.

  Therefore, consider removing the sneak signal outside the detection range. First, when the signal processing unit 17 performs phase correction for driving the sneak signal out of the detection range based on the phase of the sneak signal described above, the correction shown in the following equation (2) is performed. ΔTx1 indicates the phase shift amount with respect to the transmission signal Tx1, ΔTx2 indicates the phase shift amount with respect to the transmission signal Tx2, ΔRx1 indicates the phase shift amount with respect to the reception signal Rx1, ΔRx2 indicates the phase shift amount with respect to the reception signal Rx2, ΔRx3 indicates a phase shift amount with respect to the reception signal Rx3, and ΔRx4 indicates a phase shift amount with respect to the reception signal Rx4.

[ΔTx1, ΔTx2, ΔRx1, ΔRx2, ΔRx3, ΔRx4]
= [0deg, 180deg, 0deg, 180deg, 180deg, 0deg] (2)

  The following formula (3) is obtained by summarizing the formula (2) for each transmission / reception sequence.

[Tx1Rx1, Tx1Rx2, Tx1Rx3, Tx1Rx4, Tx2Rx1, Tx2Rx2, Tx2Rx3, Tx2Rx4]
= [0deg, 180deg, 180deg, 0deg, 180deg, 0deg, 0deg, 180deg] (3)

  In order to realize such phase adjustment, as shown in FIG. 4, in the signal processing unit 17, phase adjustment units 17-2, 17-3, 17-for transmission / reception sequences Tx1Rx2, Tx1Rx3, Tx2Rx1, Tx2Rx4. 5, 17-8 are provided to adjust the phase. Since the signal processing unit 17 is a digital signal processing unit, the phase adjustment units 17-2, 17-3, 17-5, and 17-8 can be realized by a program or the like.

  By performing the phase correction as described above in the signal processing unit 17, the angle characteristic when there is a sneak signal indicated by a broken line in FIG. 3 is a detection range as shown by the broken line in FIG. Driven out of the range of +50 deg.

  At this time, the phase of the sneak signal is expressed by the following equation (4).

[Tx1Rx1, Tx1Rx2, Tx1Rx3, Tx1Rx4, Tx2Rx1, Tx2Rx2, Tx2Rx3, Tx2Rx4]
= [0deg, 180deg, 0deg, 180deg, 0deg, 180deg, 0deg, 180deg] (4)

  That is, it can be said that the sneak component is directed outside the detection range in the radar device 10 by the phase correction processing in the signal processing unit 17.

  In the example shown in FIG. 4, not only the phase adjustment process is performed on the sneak signal, but also the phase adjustment process is performed on the reflected signal from the object. For this reason, as shown in FIG. 5, the peak of the reflected signal indicated by the solid line appears not at +20 deg but at -20 deg, and peaks also appear at other angles.

  Therefore, as shown in FIG. 1, phase adjustment units 13-2, 13-4, and 13-5 are provided for the lines connected to the high frequency port of the MMIC 10, and the phase adjustment unit 17-2 of the signal processing unit 17 is provided. , 17-3, 17-5, and 17-6, the phase adjustment shown in the following formula (5) is performed in the opposite direction. Such phase adjustment can be realized by adjusting the line length of the transmission path.

[ΔTx1, ΔTx2, ΔRx1, ΔRx2, ΔRx3, ΔRx4]
= [0deg, -180deg, 0deg, -180deg, -180deg, 0deg] (5)

  As a result, the phase adjustment in the signal processing unit 17 shown in Expression (2) is canceled out, and the phase shift amount becomes zero. Since the sneak signal does not pass through the phase adjusters 13-2, 13-4, and 13-5, it is not affected by these effects.

  FIG. 6 shows a detection result according to the embodiment shown in FIG. As shown by the solid line in FIG. 6, the reflected signal from the object has a peak at the position of +20 deg where the object exists, and the other peaks are sufficiently small compared to the peak of +20 deg. Further, it can be seen that the sneak signal shown by the broken line in FIG. 6 does not have a large peak in the detection range of −50 to +50 deg and is driven out of the range of −50 to +50 deg. When the detection range of the radar apparatus 10 is −90 to +90 deg, it is possible to detect an area that is more than half of the detection range by moving the peak of the sneak signal outside the range of −45 to +45 deg.

  As described above, according to the embodiment of the present invention, the phase adjustment process corresponding to the sneak signal is executed in the signal processing unit 17 on the low frequency side of the MMIC 11, and the phase in the opposite direction to the phase adjustment process is performed. By performing the adjustment on the high frequency side of the MMIC 11, the sneak signal is moved out of the detection range, and the object can be normally detected.

  Further, in the present embodiment, by driving the sneak signal out of the detection range, it is possible to reduce noise at a very short distance and facilitate detection of an object existing at the very short distance. FIG. 7 shows the reception amplitude at a very short distance (for example, about 5 m or less). In FIG. 7, a broken line indicates a sneak signal, and a solid line indicates a signal from an object existing at a very short distance. In FIG. 7, the horizontal axis indicates the reception time and the distance converted from the reception time, and the vertical axis indicates the signal amplitude. Since the sneak signal is received without passing through the transmitting antennas 12-1 to 12-2 and the receiving antennas 14-1 to 14-4, for example, it is present as an unnecessary signal within 1 m. Discrimination from existing objects is difficult. However, in the present embodiment, these can be easily discriminated by executing processing based on the phase peculiar to the sneak signal. Note that the width of the signal here depends on the bandwidth used by the radar, and the proposed technique is particularly suitable for a very short distance within the width of the sneaking signal in the radar itself.

(C) Description of Modified Embodiment It goes without saying that the above embodiment is merely an example, and the present invention is not limited to the case described above. For example, in the embodiment shown in FIG. 1, phase adjustment units 13-2, 13-4, and 13-5 are provided for the transmission antenna 12-2 and the reception antennas 14-2 and 14-3, and the signal processing unit 17 is provided. The phase adjustment units 17-2, 17-3, 17-5, and 17-8 are provided. However, FIG. 1 is an example, and other combinations may be used depending on the sneak signal.

In addition, the transmission / reception unit shown in FIG. 1 is configured integrally, has a plurality of transmission / reception sequences, and is small (for example, the area occupied by the MMIC within 100 mm ² or the length of one side of the MMIC having a square shape). In the case of the MMIC 11 configured to have a wavelength of approximately), adjacent transmission / reception sequence signals may be substantially in phase due to the on-chip arrangement design. The reception antennas 14-1 to 14-4 and the transmission antennas 12-1 to 12-2 may be arranged at an interval of λ / 2 from the viewpoint of suppressing the grating lobe, and the in-phase wraparound component is moved out of the detection range. In this case, the radar apparatus 10 having the detection range in the front direction can efficiently process adjacent transmission / reception sequence signals by setting them in opposite phases.

  Also, as shown in FIG. 8, phase adjustment units 13-1 to 13-6 are provided for all transmission antennas 12-1 to 12-2 and reception antennas 14-1 to 14-4, and all transmission and reception are performed. The signal processing unit 17 may be provided with phase adjustment units 17-1 to 17-6 corresponding to the series. Note that the amount of phase shift by the phase adjustment units 17-1 to 17-6 is adjusted by digital signal processing, and thus the coefficient may be adjusted. Further, the phase adjusting units 13-1 to 13-6 may be adjusted so as to have a line length that can offset the amount of phase shift by the phase adjusting units 17-1 to 17-6, as shown in FIG.

  In the embodiment shown in FIGS. 1 and 8, the case where the phase shift amounts of the phase adjustment units 17-1 to 17-6 are fixed has been described as an example. For example, the phase adjustment units 17-1 to 17-1 For each of 17-6, a plurality of transmission lines having different line lengths are prepared, and a transmission line having a desired line length is selected from these transmission lines by a switch, whereby the amount of phase shift may be variable.

  In the above embodiment, the phase shift amounts of the phase adjustment units 13-1 to 13-6 and the phase adjustment units 17-1 to 17-4 are set to 180 deg or -180 deg for the sake of simplifying the description. However, the amount of phase shift may be other than this.

  Moreover, although the detailed configuration of the MMIC 11 has not been described in the above embodiment, a configuration as illustrated in FIG. 9 may be used. In the example of FIG. 9, high-frequency ports PT1 to PT2 to which transmission antennas 12-1 to 12-2 provided on each side of a substantially square MMIC are connected and reception antennas 14-1 to 14-4 are connected. Are arranged at different positions (different sides) from the high-frequency ports PR1 to PR4 to which are connected. In addition, a transmission line connected to the transmission antennas 12-1 to 12-2 and a transmission line connected to the reception antennas 14-1 to 14-4 are lines with respect to a broken line segment passing through the center of the MMIC 11. They are arranged symmetrically. As described above, the high frequency ports PT1 to PT2 to which the transmission antennas 12-1 to 12-2 are connected and the high frequency ports PR1 to PR4 to which the reception antennas 14-1 to 14-4 are connected are arranged at positions separated from each other. Thus, a sneak signal from the transmission side to the reception side can be reduced. In addition, a transmission line connected to the transmission antennas 12-1 to 12-2 and a transmission line connected to the reception antennas 14-1 to 14-4 are lines with respect to a broken line segment passing through the center of the MMIC 11. By arranging them symmetrically, for example, the effects of temperature, humidity, etc. can be made almost equal, so the effects on all transmission lines are made almost equal, and only specific transmission lines are greatly affected. Can be prevented. If the MMIC is substantially square, it may be arranged so as to be symmetrical with respect to one diagonal line of the square. Furthermore, in the example of FIG. 9, a quadrangular shape is used, but the present invention can be applied if it is a polygonal shape.

  In the embodiment shown in FIGS. 1 and 8, the phase to be adjusted is 2 × 4 = 8 when the transmission sequence is 2 and the reception sequence is 4, but the phase that can be adjusted on the high frequency side ( The phase that can be adjusted by the phase adjusters 13-1 to 13-6) is 2 + 4 = 6. For this reason, it is not possible to completely adjust all phases with only the phase adjustment units 13-1 to 13-6. Therefore, by setting the wraparound of either the transmission sequence or the reception sequence to be all in phase, it is possible to more reliably reduce the adjustment target.

DESCRIPTION OF SYMBOLS 10 Radar apparatus 12-1 to 12-2 Transmission antenna 13-1 to 13-6 Phase adjustment part 14-1 to 14-4 Reception antenna 15 Amplifying circuit 16 A / D conversion part 17 Signal processing part 17-1 to 17- 8 Phase adjuster

Claims (10)

In a radar device that detects an object,
One or more transmission antennas and one or more reception antennas constituting a plurality of transmission / reception sequences;
A frequency conversion means for performing input / output of a transmission signal and a reception signal with respect to the transmission antenna and the reception antenna and converting the frequency of the reception signal to a lower frequency;
Estimating means for estimating the direction of the object based on information including a phase difference of a transmission / reception sequence signal frequency-converted by the frequency converting means;
First adjusting means for adjusting a phase of the transmission / reception sequence signal on a lower frequency side than the frequency converting means;
Second adjustment means for adjusting the phase of the transmission / reception sequence signal so as to cancel the phase adjustment by the first adjustment means on the higher frequency side than the frequency conversion means;
A radar apparatus comprising:   The frequency conversion means is configured as an integrated circuit including a transmission unit that outputs the transmission signal to the transmission antenna and a reception unit that receives the reception signal from the reception antenna. Item 2. The radar device according to Item 1.   The phase of the second adjusting unit is adjusted by making at least two line lengths of transmission lines between the frequency converting unit and the transmitting antenna or the receiving antenna different from each other. Or the radar apparatus of 2.   The radar apparatus according to claim 1, wherein the first adjustment unit adjusts a phase by performing digital signal processing on the transmission / reception sequence signal. The frequency conversion means includes
A transmission unit that outputs the transmission signal to the transmission antenna;
A reception unit to which the reception signal is input from the reception antenna;
The first adjustment means moves the sneak signal out of a detection angle range for detecting an azimuth by adjusting a phase of a sneak signal that wraps around from the transmission unit to the reception unit. 5. The radar device according to any one of 4 above. An adjacent set of the transmitting antennas of the transmitting antennas or an adjacent set of the transmitting antennas of the receiving antennas has an interval of λ / 2 when the wavelength of the received signal is λ. Placed in
The second adjustment unit performs phase adjustment so that the transmission signal or the reception signal corresponding to at least one pair of the transmission antennas or the reception antennas adjacent to each other has a substantially opposite phase.
The radar device according to any one of claims 1 to 5, wherein   The radar apparatus according to claim 2, wherein transmission sequences of reception signals from the transmission unit to the reception unit of the integrated circuit or reception sequences are set to be substantially in phase.   A transmission path connecting the integrated circuit and the transmitting antenna or a transmission path connecting the integrated circuit and the receiving antenna is arranged symmetrically with respect to a line segment passing through the center of the integrated circuit. The radar apparatus according to claim 2.   The first adjustment means adjusts the phase so that the peak of the sneak signal from the transmission unit to the reception unit is at an angle of 45 degrees or more from the center of the detection range. The radar apparatus described. The integrated circuit is polygonal and has a plurality of ports to which a plurality of transmission lines are connected along the sides of the polygon.
The transmission path connecting the integrated circuit and the transmitting antenna and the transmission path connecting the integrated circuit and the receiving antenna are connected to ports along different sides.
The radar apparatus according to any one of claims 2 and 7 to 9.

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