JP2009281775A - Radar system and compensation quantity calculation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar system having a plurality of transmitting channels or receiving channels in which a characteristic difference between the transmitting channels or the receiving channels can be compensated stably over a long period of time without increasing a scale of the system. <P>SOLUTION: The radar system 1 is constituted of a plurality of receiving ICs 42, 43 on which receiving circuits for two channels are integrated. When phase differences Δθ<SB>12</SB>, Δθ<SB>34</SB>between adjacent receiving channels belonging to the same chip (receiving IC) match, it is determined that a reception signal is based on a reflected wave from a single target, and compensation quantity calculation data Δθd are calculated. Here, as data which are not influenced by the characteristic difference between the receiving channels, the phase differences Δθ<SB>12</SB>, Δθ<SB>34</SB>are used, while as data which are influenced by the characteristic difference between the receiving channels, a phase difference Δθ<SB>23</SB>between adjacent receiving channels belonging to difference chips is used. On the basis of these, the compensation quantity calculation data Δθd, and also a compensation quantity Δθh are calculated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radar apparatus having a plurality of transmission channels or reception channels.

  Conventionally, information (distance) about a target that has a plurality of reception channels that receive reflected waves of transmitted radar waves via a reception antenna and reflects the radar waves based on a signal supplied from each reception channel. , Azimuth, speed, etc.) are known.

  In this type of radar equipment, if the characteristics (gain and path length) of each reception channel vary due to temperature changes and aging of the characteristics of the transmission path for transmitting the received signal and the analog circuit for processing the received signal, The detection accuracy deteriorates, and particularly when the frequency of the radio wave used is high, the influence appears remarkably.

  In contrast, a pseudo reception signal with a known characteristic is supplied to each reception channel instead of the reception signal from the reception antenna, and the characteristic of each reception channel is measured from the signal processing result. Based on the measurement result, Calculates a correction value to compensate for the characteristic difference between reception channels, and uses the correction value to correct the output signal output from each reception channel when the reception signal from the reception antenna is supplied to each reception channel. (For example, refer to Patent Document 1).

Further, instead of inputting a pseudo reception signal, a correction value is calculated using a reception signal based on a reflected wave from a radome protecting the antenna (see, for example, Patent Document 2).
JP 7-218617 A JP 2007-93480 A

  However, in the conventional apparatus described in Patent Document 1, a new circuit such as a circuit for generating a pseudo reception signal or a switch for switching between a reception signal from the reception antenna and a pseudo reception signal and supplying the reception signal to each reception channel is provided. There is a problem that the configuration is necessary and the scale and cost of the apparatus increase.

  Also, in a device that uses the millimeter wave band, the transmission path used to supply the pseudo reception signal to each reception channel also varies in characteristics due to temperature changes, etc., and the same pseudo reception signal is accurately received in each reception channel. There is also a problem that it is difficult to keep supplying well, and it is not possible to stably obtain an accurate correction value (and information on a target reflecting a radar wave) over a long period of time.

  In addition, in the conventional device described in Patent Document 2, it is not necessary to provide a new circuit for obtaining the correction value, but the path length between the transmitting antenna, the radome, and the receiving antenna is reduced due to deformation of the structure due to a temperature change or the like. If the reflection characteristics of the radome change due to changes or scratches caused by stepping stones or dirt due to snow, rain, mud, etc., the characteristics of the reflected wave from the radome will vary for each receiving antenna (receiving channel). As with the conventional device described in Patent Document 1, there is a problem that a highly accurate correction value cannot be obtained stably over a long period of time.

Such a problem occurs not only when there are a plurality of reception channels as described above, but also when there are a plurality of transmission channels.
In order to solve the above-described problems, the present invention provides a radar apparatus having a plurality of transmission channels or reception channels, in which a characteristic difference between the transmission channels or the reception channels is increased over a long period of time without increasing the apparatus scale. The purpose is to enable stable compensation.

  In the radar apparatus according to claim 1, which is an invention made to achieve the above object, the transmission means transmits a radar wave via the transmission antenna, and a plurality of reception channels constituting the reception means are transmitted from the transmission means. The reflected wave of the transmitted radar wave is received via the receiving antenna. The receiving means is configured by using a plurality of integrated circuits in which a plurality of receiving channels are integrated on one chip.

  Then, the correcting means corrects the output signal from the receiving means so that the difference value between the receiving channels caused by the characteristic difference between the receiving channels is compensated, and the signal processing means converts the output signal to the corrected output signal. Based on this, information on the object reflecting the radar wave is obtained. The characteristic difference between the reception channels is specifically a gain difference or a path difference, and the difference value between the reception channels is specifically an amplitude difference or a phase difference. is there.

  Further, the compensation amount calculating means includes an in-circuit difference value that is a difference value between adjacent reception channels belonging to the same integrated circuit, and an inter-circuit difference that is a difference value between adjacent reception channels belonging to different integrated circuits. The difference from the value is obtained as a compensation amount to be compensated by the correcting means.

  In other words, even if the characteristics of the integrated circuit change based on a temperature change or the like, the characteristic changes of the reception channels belonging to the same integrated circuit are all the same, so that there is no characteristic difference between them. As a result, the in-circuit difference value is not affected by the characteristic difference between the reception channels. On the other hand, since reception channels belonging to different integrated circuits cause different characteristic changes, there is a characteristic difference between them. As a result, the inter-circuit difference value is influenced by the characteristic difference between the reception channels. Therefore, the difference between the in-circuit difference value and the inter-circuit difference value is a compensation amount to be compensated.

  According to the radar apparatus of the present invention configured as described above, a normal reflected wave can be used without requiring a special pseudo reception signal or the like for calculation of the in-circuit difference value and the inter-circuit difference value. The apparatus scale is not increased, and unlike the conventional apparatus described in the cited document 2, it is not affected by changes in the components other than the reception channel, so that the characteristic difference between the reception channels is increased for a long time. It is possible to compensate stably over the range.

  By the way, in the radar apparatus of the present invention, as described in claim 2, the determination unit determines whether the output signal from the reception unit is based on a reflected wave from a single target, and compensates for it. The amount calculation means desirably obtains the compensation amount when the determination means makes an affirmative determination.

This is because there is a possibility that the difference value cannot be obtained accurately when the reflected waves from a plurality of targets are mixed.
In this case, for example, as described in claim 3, the determination unit obtains an in-circuit difference value for each integrated circuit, and variation in the in-circuit difference value is equal to or less than a predetermined determination threshold value. The digital signal may be configured to be determined as a single target, or digitally output using an output signal obtained from each reception channel belonging to any one of the integrated circuits as claimed in claim 4. The beam forming may be performed so that the number of beams larger than a preset power threshold value is obtained as the number of targets, or as any one of the integrated circuits according to claim 5, An autocorrelation matrix of an output signal obtained from each receiving channel to which the signal belongs may be obtained, and the number of targets may be obtained from the magnitude of the eigenvalue of the autocorrelation matrix.

  Next, according to the radar device of the present invention, when a mixer for mixing a reception signal from a reception antenna and a local signal is provided for each reception channel, the integrated circuit includes It is desirable that a distribution circuit for distributing the local signal to the mixer of each reception channel belonging to the integrated circuit is also integrated.

  The radar apparatus according to the present invention, as described in claim 7, when each reception channel belonging to the same integrated circuit is configured to use a common mixer in a time division manner, the integrated circuit includes: It is desirable that a selection circuit that selects and outputs one of the output signals from the reception channel belonging to the integrated circuit is integrated.

As described above, by integrating the distribution circuit and the selection circuit in the integrated circuit, the characteristics of the reception channels belonging to the same integrated circuit can be made uniform with higher accuracy.
The above description is for the case where the receiving means is configured by using a plurality of integrated circuits in which a plurality of receiving channels are integrated on a single chip. The same can be said for a configuration constituted by using a plurality of integrated circuits integrated on a chip.

  In this case, as described in claim 8, the compensation amount calculating means includes an in-circuit difference value that is a difference value between adjacent transmission channels belonging to the same integrated circuit, and an adjacent transmission that belongs to different integrated circuits. A difference from the inter-circuit difference value, which is a difference value between channels, is obtained as a compensation amount to be compensated by the correcting means.

  According to the radar apparatus of the present invention configured as described above, similarly to the radar apparatus according to claim 1, the characteristic difference between the reception channels is stabilized over a long period of time without increasing the apparatus scale. Can be compensated.

  When the transmission channels are all configured to receive a transmission signal from the same signal generation source as described in claim 9, the integrated circuit includes each transmission channel belonging to the integrated circuit. It is desirable that a distribution circuit for distributing the transmission signal is integrated.

According to the radar apparatus of the present invention configured as described above, the characteristics of the transmission channels belonging to the same integrated circuit can be made uniform with higher accuracy.
Next, the invention according to claim 10 includes a transmission means for transmitting a radar wave via a transmission antenna, and a plurality of reception channels for receiving a reflected wave of the radar wave transmitted from the transmission means via a reception antenna. And a receiving device configured by using a plurality of integrated circuits each having a plurality of receiving channels integrated on one chip, an output signal from the receiving device is generated due to a characteristic difference between the receiving channels. A compensation amount calculation method for calculating a compensation amount used for correction so that a difference value between the reception channels is compensated, wherein the in-circuit difference is a difference value between adjacent reception channels belonging to the same integrated circuit. The difference between the value and the inter-circuit difference value that is a difference value between adjacent reception channels belonging to different integrated circuits is obtained as a compensation amount.

  The invention according to claim 11 is configured by using a plurality of integrated circuits having a plurality of transmission channels for transmitting radar waves via a transmission antenna and integrating a plurality of transmission channels on one chip. In a radar apparatus including a transmission unit and a reception unit that receives a reflected wave of a radar wave transmitted from the transmission unit via a reception antenna, an output signal from the output unit is generated due to a characteristic difference between transmission channels. A compensation amount calculation method for calculating a compensation amount used for correction so that a difference value between reception channels is compensated, wherein the in-circuit difference value is a difference value between adjacent transmission channels belonging to the same integrated circuit. And a difference between inter-circuit difference values, which are difference values between adjacent transmission channels belonging to different integrated circuits, as a compensation amount.

  According to these compensation amount calculation methods of the present invention, the compensation amount can be obtained from the received signal based on the reflected wave of the radar wave transmitted from the radar apparatus without using a special pseudo received signal or the like. In addition, according to the compensation amount calculation method of the present invention, the obtained compensation amount is not affected by the characteristic change of the portions other than the reception channel and the transmission channel, so that the characteristic difference between the channels is accurately compensated. be able to.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing the overall configuration of an in-vehicle radar device 1 to which the present invention is applied.
<Overall configuration>
As shown in FIG. 1, the radar apparatus 1 includes a single transmission antenna AS that transmits a radar wave, an antenna unit 2 that includes reception antennas AR1 to AR4 that receive a reflected wave of the radar wave, and a transmission signal to the transmission antenna AS. And a signal processing module 4 for processing received signals from the respective receiving antennas AR1 to AR4, and a transmission path (guide for transmitting transmission signals and received signals between the antenna unit 2 and the signal processing module 4). IF section 3 forming a wave tube).

  The signal processing module 4 is configured to individually process the reception signals from the reception antennas ARi (i = 1 to 4). Hereinafter, a circuit for processing the reception signals from the reception antennas ARi will be described. It is also collectively referred to as a reception channel CHi.

The radar apparatus 1 also includes an A / D conversion unit 5 that converts an output signal output from the signal processing module 4 for each of the reception channels CH1 to CH4 into digital data, and digital data converted by the A / D conversion unit 5. And an arithmetic processing unit 6 that executes various processes based on the above.
<Signal processing module>
The signal processing module 4 includes a transmission integrated circuit (hereinafter referred to as a transmission IC) 41 in which a transmission circuit that generates a transmission signal and a local signal is integrated, and a reception circuit that generates a beat signal based on the reception signal and the local signal ( The receiving channel is composed of receiving integrated circuits (hereinafter referred to as receiving ICs) 42 and 43 each having two channels.

  The transmission IC 41, in accordance with a command from the arithmetic processing unit 6, generates an oscillator OSC that generates a millimeter-wave band high-frequency signal, a distributor DV that generates a transmission signal and a local signal by distributing the output of the oscillator OSC, and a transmission It has a known circuit configuration including an amplifier A1 for amplifying a signal and an amplifier A2 for amplifying a local signal.

  On the other hand, in the reception IC 42 (the reception IC 43 is exactly the same), the reception circuit provided corresponding to each input reception signal outputs the output of the amplifier A3 and the amplifier A3 that amplifies the reception signal and the local signal. It has a known circuit configuration comprising a mixer MIX that generates a beat signal by mixing, and an amplifier A4 that amplifies the output (beat signal) of the mixer MIX.

  Further, the reception IC 42 includes an input buffer BF provided with a local signal at an input terminal, and a branch circuit BL which branches the local signal taken in via the input buffer BF into two receiving circuits.

  In the receiving IC 42, the two receiving circuits (especially the mixer MIX) are positioned symmetrically with respect to the branch circuit BL so that the transmission path lengths of the local signals from the branch circuit BL to the receiving circuit are equal. Has been placed.

Further, each part of the signal processing module 4 (transmission IC 41, reception ICs 42, 43, local signal supply transmission path, etc.) is a local signal supply transmission path length from the transmission IC 41 to each reception IC 42, 43. Are laid out to be equal.
<A/D converter>
The A / D converter 5 performs A / D conversion on the outputs of the bandpass filter BPFi and the bandpass filter BPFi that remove unnecessary noise components from the beat signal generated by the signal processing module 4 for each of the reception channels CHi. An A / D converter ADi is provided.
<Operation processing unit>
The arithmetic processing unit 6 is mainly configured by a microcomputer including a CPU, a ROM, and a RAM. The arithmetic processing unit 6 outputs a command for generating a transmission signal to the transmission IC 41 and converts the digital data acquired via the A / D conversion unit 5 into the digital data. Compensation used when performing target detection processing for obtaining information (relative speed, distance, azimuth, etc.) related to a target reflected from a radar wave, or correction for compensating for a characteristic difference between the receiving channels CH1 to CH4. At least compensation amount calculation processing for obtaining the amount is executed.
<< Target detection process >>
Details of the target detection process executed by the arithmetic processing unit 6 will be described with reference to the flowchart shown in FIG.

This process starts periodically when power supply to the radar apparatus 1 is started until the power supply stops.
When this processing is started, first, in S110, a command is issued to the transmission IC 41 so that the radar apparatus 1 operates as an FMCW radar so as to generate a high-frequency signal modulated so that the frequency changes in a triangular wave shape. The data obtained by A / D conversion of the beat signal is obtained for all reception channels CH1 to CH4 via the A / D conversion unit 5.

Hereinafter, a section in which the frequency of the transmission signal increases is referred to as an uplink modulation section, and a section in which the frequency decreases is referred to as a downlink modulation section.
In S120, a data correction process for correcting the digital data is performed so that the characteristic difference between the reception channels is compensated by the compensation amount Δθh calculated by the compensation amount calculation process described later. In S130, the correction is performed. Using digital data, a fast Fourier transform (FFT) process is executed for each reception channel and each modulation section.

  In S140, the arrival direction of the reflected wave is obtained by performing digital beam forming (DBF) for each modulation section and for each frequency (peak frequency) at which a peak is detected by FFT processing. In S150, the direction detected by the DBF In addition, based on the past detection results, pair matching processing is performed in which the peak frequency based on the reflected wave from the same target is combined in the upstream modulation section and the downstream modulation section.

  In S160, based on the peak frequency pair combined in S150, the distance to the target (detected target) that generated the peak frequency pair and the relative speed are calculated, and these distance, relative speed, and peak frequency are calculated. The azimuth | direction calculated by previous S140 about a pair is output as target information (distance, relative speed, azimuth | direction) of a detected target, and this process is complete | finished.

These processes are well-known processes in FMCW radar and DBF radar.
<< Compensation amount calculation process >>
Next, details of the compensation amount calculation processing executed by the arithmetic processing unit 6 will be described with reference to the flowchart shown in FIG.

  This process is executed when a preset activation condition is satisfied. Specifically, it may be executed periodically (a period sufficiently longer than the target detection process) when the engine of the vehicle is started or when a command is input from the driver.

When this process is started, first, in S210, data obtained by A / D converting the beat signal is acquired for all reception channels CH1 to CH4, as in S110.
In S220, FFT processing is performed for each reception channel and for each modulation section. In subsequent S230, the received signal vector X = (X ₁ , X ₂ , X ₃ , for each modulation section and for each peak frequency component from the FFT processing result. X ₄ ) is generated. X _i = A _i e ^j θ ⁱ is a peak frequency component in the reception channel CH _i , A _i represents an amplitude, and θ _i represents a phase.

In S240, an unprocessed signal is extracted from the received signal vectors X generated in S230 as a processing target vector. In S250, based on the extracted processing target vector, the same in-chip phase difference (in the present invention) is extracted. corresponding to the circuit in the differential value), i.e., calculates the phase difference [Delta] [theta] between the reception channels CH1, CH2 ₁₂ ((1) see formula), the phase difference [Delta] [theta] ₃₄ between the receiving channel CH3,4 ((2) see formula) To do.

In S260, it is determined whether or not the absolute value of the difference between both phase differences Δθ ₁₂ and Δθ ₃₄ is smaller than a preset threshold value α (see equation (3)).

When an affirmative determination is made in S260, that is, when both phase differences Δθ ₁₂ and Δθ ₃₄ match, the peak frequency component corresponding to the processing target vector is based on a reflected wave from a single target. Then, the process proceeds to S270.

In S270, based on the processing target vector different inter-chip phase difference (equivalent to the circuit between the difference value in the present invention), i.e., it calculates the phase difference [Delta] [theta] ₂₃ between the reception channels CH2, CH3 ((4) see formula).

  In S280, the compensation amount calculation data Δθd is obtained according to the equation (5), accumulated, and the process proceeds to S290.

On the other hand, when a negative determination is made in the previous S260, that is, when both the phase differences Δθ ₁₂ and Δθ ₃₄ do not match, the peak frequency component corresponding to the processing target vector is based on the reflected wave from the plurality of targets. As it is, the process proceeds to S290 as it is.

In S290, it is determined whether or not there is an unprocessed received signal vector X. If there is an unprocessed received signal vector X, the process returns to S240, and the processes in S240 to S280 are repeated.
If it is determined in S290 that there is no unprocessed received signal vector X, the process proceeds to S300, in which the accumulated number of compensation amount calculation data Δθd accumulated in S280 reaches a preset necessary accumulated number. If the required accumulation number has not been reached, the process returns to S210 and the processes of S210 to S290 are repeated. If the required accumulation number has been reached, the process proceeds to S310.

In S310, the compensation amount Δθh is calculated based on the accumulated compensation amount calculation data Δθd, and the process is terminated.
As the compensation amount Δθh, for example, an average value of compensation amount calculation data Δθd can be used.

The compensation amount θh represents a characteristic difference between the receiving ICs 42 and 43 that are different from each other. Therefore, the correction in S120 is performed for two receiving channels belonging to one of the receiving ICs 42 and 43. All the acquired digital data may be corrected so that the compensation amount Δθh is compensated.
<Effect>
As described above, the radar apparatus 1 uses the phase differences Δθ ₁₂ and Δθ ₃₄ between adjacent reception channels belonging to the same chip (reception IC) as data that is not affected by the characteristic difference between the reception channels. As the data affected by the characteristic difference between the receiving channels, the phase difference Δθ ₂₃ between adjacent receiving channels belonging to different chips is used, and based on these, the compensation amount calculation data Δθd and thus the compensation amount Δθh are obtained. Yes.

  Therefore, according to the radar apparatus 1, a special pseudo reception signal is not required for calculating the compensation amount Δθh, and a reception signal based on a normal reflected wave can be used, so that the apparatus scale is not increased. In addition, since the compensation amount Δθh is not affected by changes in components other than the reception channel, the characteristic difference between the reception channels can be stably compensated for a long period of time.

Further, in the radar apparatus 1, the compensation amount calculation data Δθd is obtained only when the received signal is based on the reflected wave from the single target, and is the received signal based on the reflected wave from the single target. Is determined based on the phase differences Δθ ₁₂ and Δθ ₃₄ used for calculating the compensation amount calculation data Δθd.

Therefore, according to the radar apparatus 1, the accuracy of the compensation amount Δθh can be improved with a small amount of processing.
[Second Embodiment]
Next, a second embodiment will be described.
<Overall configuration>
FIG. 4 is a block diagram showing the overall configuration of the radar apparatus 1a according to the second embodiment.

  As shown in FIG. 4, the radar apparatus 1a includes a plurality of transmission antennas AS1 to AS4 that transmit radar waves, an antenna unit 2a that includes a single reception antenna AR that receives a reflected wave of the radar wave, and each transmission antenna AS1. A signal processing module 4a for supplying a transmission signal to the AS and processing a reception signal from the reception antenna AR, and a transmission path for transmitting the transmission signal and the reception signal between the antenna unit 2a and the signal processing module 4a IF section 3a forming (waveguide).

  The signal processing module 4a is configured to individually supply transmission signals to the transmission antennas ASi (i = 1 to 4), and hereinafter, a circuit for supplying transmission signals to the transmission antennas ASi is referred to as a transmission channel. Also called CHi.

Further, the radar apparatus 1a executes an A / D conversion unit 5a that converts an output signal output from the signal processing module 4 into digital data, and various processes based on the digital data converted by the A / D conversion unit 5a. And an arithmetic processing unit 6a.
<Signal processing module>
The signal processing module 4a includes a transmission integrated circuit (hereinafter referred to as a transmission IC) 45 in which a transmission circuit that generates a transmission signal and a local signal is integrated, and a 1-input 2-output switching integrated circuit that switches an output destination of the transmission signal. (Hereinafter referred to as a switching IC) 46, 47, 48, a reception integrated circuit (hereinafter referred to as a reception IC) that generates a beat signal based on a reception signal from the reception antenna AR and a local signal from the transmission IC 45 49.

  The transmission IC 45, in accordance with a command from the arithmetic processing unit 6, generates an oscillator OSC that generates a millimeter-wave band high-frequency signal, a distributor DV that generates a transmission signal and a local signal by distributing the output of the oscillator OSC, and a transmission It has a known circuit configuration including an amplifier A1 for amplifying a signal and an amplifier A2 for amplifying a local signal.

  The input terminal of the switching IC 46 is connected to the output terminal for transmitting signal output of the transmitting IC 45, and the input terminals of the switching ICs 47 and 48 are connected to one of the two output terminals of the switching IC 46, respectively. The output terminals of the switching ICs 47 and 48 are connected to transmission lines that reach the transmission antennas AS1 to AS4, respectively.

  Further, the switching ICs 47 and 48 are each provided with an amplifier A5 on an individual line in the IC reaching each output terminal. However, since a specific configuration for switching is a well-known technique, illustration is omitted for easy understanding of the drawing. The switching ICs 46, 47, 48 are laid out so that the transmission path lengths from the transmission signal output end of the transmission IC 45 to the input ends of the switching ICs 46, 47 are equal.

On the other hand, the receiving IC 49 includes an amplifier A3 that amplifies the received signal, a mixer MIX that generates a beat signal by mixing the output of the amplifier A3 and the local signal, and an amplifier A4 that amplifies the output (beat signal) of the mixer MIX. It has a well-known circuit configuration.
<A/D converter>
The A / D converter 5a is a bandpass filter BPF that removes unnecessary noise components from the beat signal generated by the signal processing module 4, and an A / D converter AD that A / D converts the output of the bandpass filter BPF. It has.
<Operation processing unit>
In the arithmetic processing unit 6a, by operating the switching ICs 46, 47 and 48, the transmission antennas AS1 to AS4 are sequentially transmitted with radar waves (time division operation), and digital data obtained by A / D conversion is obtained. Except for separation for each of the transmission channels CH1 to CH4, the same processing as the arithmetic processing unit 6 in the radar apparatus 1 is executed.
<Effect>
According to the radar apparatus 1a configured as described above, the same effect as that of the radar apparatus 1 can be obtained only by the difference between the transmission channel and the reception channel.
[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can implement in various aspects.

In the above embodiment, digital data obtained by A / D conversion is corrected, but the result of the FFT processing may be corrected.
In the above embodiment, the compensation amount calculation process collects data separately from the target detection process. However, the compensation amount Δθh may be obtained using the data collected in the target detection process.

  In the above-described embodiment, the compensation amount Δθh is calculated after the necessary amount of compensation amount data Δθd is accumulated. However, every time the compensation amount calculation data Δθd is calculated, the compensation amount Δθh is updated. You may comprise. In this case, specifically, the compensation amount Δθh may be obtained from the compensation amount calculation data Δθd using a load average or moving average method.

In the above embodiment, the case where the phase difference is used as the difference value between the reception channels has been described. However, the amplitude difference may be used instead of or together with the phase difference.
In the above embodiment, two channels are integrated in the receiving IC and the switching IC. However, as long as a channel with uniform characteristics can be formed, an integrated circuit of three or more channels may be used. Further, the number of receiving ICs or switching ICs themselves may be three or more.

In the above embodiment, whether the received signal based on the reflected waves from a single target object, the phase difference between adjacent channels belonging to the same chip [Delta] [theta] _12, it is determined by whether or not [Delta] [theta] ₃₄ is coincident However, the present invention is not limited to this. For example, digital beam forming is performed using received signals for the respective channels belonging to the same chip, and the number of beams larger than a preset power threshold is obtained as the number of targets. You may judge.

  Further, for example, the determination may be made by obtaining the autocorrelation matrix of the received signal from the received signal for each channel belonging to the same chip and obtaining the number of targets from the magnitude of the eigenvalue of the autocorrelation matrix.

  In the first embodiment, each of the reception channels CH1 to CH4 includes the mixer MIX. However, for the reception channels belonging to the same chip, a configuration is adopted in which a common mixer provided outside the chip is used in a time-sharing manner. May be. In this case, however, it is desirable that each chip (receiving IC) is integrated with a selection circuit that selects one of the output signals from both reception channels and outputs the selected signal to the mixer.

1 is a block diagram showing a configuration of a radar apparatus according to a first embodiment. The flowchart which shows the content of the target detection process. The flowchart which shows the content of the compensation amount calculation process. The block diagram which shows the structure of the radar apparatus of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a ... Radar apparatus 2, 2a ... Antenna part 3, 3a ... IF part 4, 4a ... Signal processing module 5, 5a ... A / D conversion part 6, 6a ... Arithmetic processing part 41, 45 ... Integrated circuit for transmission 42 , 43, 49... Receiving integrated circuits 46 to 48... Switching integrated circuits A1 to A5... Amplifiers AD1 to AD5, AD... A / D converters AD1 to AD4, AD ... A / D converters AR1 to AR4, AR. Reception antenna AS, AS1 to AS4 ... Transmission antenna BF ... Input buffer BL ... Branch circuit BPF1 to BPF4, BPF ... Bandpass filter DV ... Distributor MIX ... Mixer OSC ... Oscillator

Claims (11)

A transmission means for transmitting a radar wave via a transmission antenna;
Receiving means having a plurality of receiving channels for receiving the reflected wave of the radar wave transmitted from the transmitting means via a receiving antenna;
Correcting means for correcting the output signal from the receiving means so that a difference value between the receiving channels caused by a characteristic difference between the receiving channels is compensated;
Based on the output signal corrected by the correction means, signal processing means for obtaining information on the object reflected from the radar wave;
In a radar apparatus equipped with
The receiving means is constituted by using a plurality of integrated circuits in which a plurality of the receiving channels are integrated on one chip, and
The difference between an in-circuit difference value that is a difference value between adjacent reception channels belonging to the same integrated circuit and an inter-circuit difference value that is a difference value between adjacent reception channels that belong to different integrated circuits is corrected. A radar apparatus comprising: a compensation amount calculating means for obtaining a compensation amount to be compensated by the means. Determining means for determining whether an output signal from the receiving means is based on a reflected wave from a single target;
The radar apparatus according to claim 1, wherein the compensation amount calculation unit obtains the compensation amount when an affirmative determination is made by the determination unit.   The determination means determines the in-circuit difference value for each integrated circuit, and determines that the difference is not more than a predetermined determination threshold value and is a single target. The radar apparatus according to claim 2.   The determination means performs digital beam forming using the output signal obtained from each reception channel belonging to any one of the integrated circuits, and sets the number of beams larger than a preset power threshold as the number of targets. The radar apparatus according to claim 2, wherein the radar apparatus is obtained.   The determining means obtains an autocorrelation matrix of the output signal obtained from each reception channel belonging to any one of the integrated circuits, and obtains the number of targets from the magnitude of the eigenvalue of the autocorrelation matrix. The radar apparatus according to claim 2. For each reception channel, a mixer for mixing a reception signal from the reception antenna and a local signal is provided,
6. The radar apparatus according to claim 1, wherein a distribution circuit that distributes the local signal to a mixer of each reception channel belonging to the integrated circuit is integrated in the integrated circuit. . Each receiving channel belonging to the same integrated circuit is configured to use a common mixer in a time division manner, and
6. The integrated circuit according to claim 1, wherein a selection circuit that selects and outputs one of output signals from a reception channel belonging to the integrated circuit is integrated in the integrated circuit. Radar equipment. A transmission means having a plurality of transmission channels for transmitting radar waves via a transmission antenna;
Receiving means for receiving the reflected wave of the radar wave transmitted from the transmitting means via a receiving antenna;
Correcting means for correcting the output signal from the receiving means so that a difference value between the transmission channels caused by a characteristic difference between the transmission channels is compensated;
Based on the output signal corrected by the correction means, signal processing means for obtaining information on the object that has reflected the radar wave;
In a radar apparatus equipped with
The transmission means is configured using a plurality of integrated circuits in which a plurality of the transmission channels are integrated on one chip, and
The difference between the in-circuit difference value, which is a difference value between adjacent transmission channels belonging to the same integrated circuit, and the inter-circuit difference value, which is a difference value between adjacent transmission channels belonging to different integrated circuits, is corrected. A radar apparatus comprising: a compensation amount calculating means for obtaining a compensation amount to be compensated by the means. The transmission channels are all configured to receive a transmission signal from the same signal generation source,
9. The radar apparatus according to claim 8, wherein a distribution circuit that distributes the transmission signal to each transmission channel belonging to the integrated circuit is integrated in the integrated circuit. Transmitting means for transmitting a radar wave via a transmitting antenna, and a plurality of receiving channels for receiving a reflected wave of the radar wave transmitted from the transmitting means via a receiving antenna. And a receiving device configured using a plurality of integrated circuits integrated on a chip, a difference value between the receiving channels generated by a difference in characteristics between the receiving channels is obtained from an output signal from the receiving device. A compensation amount calculating method for calculating a compensation amount used when correcting so as to be compensated,
The difference between an in-circuit difference value that is a difference value between adjacent receiving channels belonging to the same integrated circuit and an inter-circuit difference value that is a difference value between adjacent receiving channels belonging to different integrated circuits is compensated for A compensation amount calculation method characterized in that the compensation amount is obtained as an amount. A transmission means having a plurality of transmission channels for transmitting radar waves via a transmission antenna, and comprising a plurality of integrated circuits in which the plurality of transmission channels are integrated on one chip; And a receiving means for receiving a reflected wave of the radar wave via a receiving antenna, the output signal from the output means has a difference value between the receiving channels caused by a characteristic difference between the transmitting channels. A compensation amount calculation method for calculating a compensation amount used when correcting so as to be compensated,
Compensating for a difference between an in-circuit difference value which is a difference value between adjacent transmission channels belonging to the same integrated circuit and an inter-circuit difference value which is a difference value between adjacent transmission channels belonging to different integrated circuits A compensation amount calculation method characterized in that it is obtained as a quantity.

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