JP2001296351A - Transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a conventional problem such that at a quantity of operations is unfairly increased. SOLUTION: There are provided an A/D converter 5A for converting analog signals outputted from a transmitter 2 to digital signals, an A/D converter 5B for converting analog signals outputted from a receiver 4 to digital signals, a coherent integrating circuit 7A for Fourier transforming output signals of the A/D converter 5A, a coherent integrating circuit 7B for Fourier transforming output signals of the A/D converter 5B, a correlating circuit 8 for multiplying frequency components of a signal obtained by Fourier transforming the signal outputted from the transmitter and a signal obtained by Fourier transforming the received signal, a band pass filter 9 for passing only received signal components from a region to be referred to among the output signals from the correlating circuit 8, and a coherent integrating circuit 10 for inverse Fourier transforming the output signal from the band pass filter 9. Processing can be sped up accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception device that can be used as a radar by detecting a signal received by an antenna, reflecting a radio wave transmitted for the purpose of interference. .

[0002]

2. Description of the Related Art A conventional transmitting / receiving apparatus will be described with reference to the drawings. FIG. 13 is a block diagram showing a configuration of a conventional transmitting / receiving apparatus.

In FIG. 13, 1 is a transmitting antenna for transmitting a radio wave for the purpose of interference, 2 is a transmitter for generating a transmission signal for the purpose of interference, 3 is a receiving antenna for receiving a radio wave,
Reference numeral 4 denotes a receiver for performing band limitation and phase detection on a signal received by the receiving antenna, and reference numerals 5A and 5B denote A / D converters for converting analog signals output from the transmitter 2 and the receiver 4 into digital signals. .

[0004] In the same figure, 7A and 7B are A / A
A coherent integration circuit that performs a Fourier transform on the output signals from the D converters 5A and 5B, and a coherent integrator 8 performs the Fourier transform on the signal output from the transmitter 2 and the frequency component of the Fourier transform signal on the received signal. A correlation circuit 10 for performing multiplication is a coherent integration circuit for performing an inverse Fourier transform on an output signal from the correlation circuit 8.

Further, in FIG. 1, reference numeral 18 denotes a coherent integrating circuit 7A, 7B, a correlating circuit 8, and a coherent integrating circuit 10, and a reference signal generated based on a Fourier-transformed signal of the received signal and a transmitted signal. The pulse compression processing system performs a pulse compression process by multiplying a signal obtained by Fourier-transforming the signal for each component and performing an inverse Fourier transform thereof. Reference numeral 11 denotes a target detection processing system.

Next, the operation of the above-mentioned conventional transmitting / receiving apparatus will be described with reference to the drawings.

For the purpose of paralyzing the target radar function, a transmitter 2 generates a transmission signal, and a transmission antenna 1 radiates radio waves toward the target. The transmitter 2 transmits a wideband signal to interfere with various frequencies of radio waves transmitted from the target.

FIG. 14 shows the relationship between the transmission band and the transmission frequency. The transmission band is divided into N, and f1 to fN are randomly selected to generate a transmission signal.

FIG. 15 shows a procedure for generating a transmission signal.

In step 100, the process starts.

Next, in step 101, the period L of the random signal and the N types of transmission frequencies (f1, f2,
.., FN). The period L of the random signal is set sufficiently large so that the periodicity cannot be detected on the target side.

Next, at step 102, by randomly selecting M transmission frequencies from f1 to fN,
f′1, f′2,..., f′L are set.

Next, in step 103, f'1,
.., f′L,..., f′L
s'2, ..., s'L are generated.

Then, in step 104, transmission signals s1, s2,... Are generated using the following equation (1). Note that the subscript (k mod L) of s ′ is the number of remainders obtained by dividing k by L.

S _k = s ′ _{k mod L} (1)

According to the above procedure, a signal having a pulse width of N / transmission band in which the frequency from f1 to fN fluctuates randomly in L periods is transmitted.

The signal transmitted from the transmitting antenna 1 is received by a receiving antenna mounted on the target. When the radar mounted on the target uses the transmission signal of the transmission frequency fj, the signal of the transmission frequency fj is received by the target receiving antenna at a rate of one pulse out of N pulses. At this time, the signal of fj transmitted from the transmission antenna 1 is superimposed on the signal of the transmission frequency fj transmitted from the target side, and received by the target reception antenna. Since the signal transmitted from the transmission antenna 1 is superimposed on the target reception antenna in addition to the transmission signal transmitted from the target reception antenna,
A situation occurs in which phase information and the like necessary for radar ranging are lost, and the target radar function deteriorates.

The signal transmitted from the transmitting antenna 1 and reflected on the target is received by the receiving antenna 3. Receiver 4
As a result, band limitation and phase detection are performed on the received signal (received signal), and a complex signal is output. The signal output from the receiver 4 is input to the A / D converter 5B, and a digital signal in cell units is output.

The signals transmitted by the transmitting antenna 1 and the transmitter 2 are also input to the A / D converter 5A, and the output signal from the A / D converter 5A generates a reference signal for each cell. A received signal output from A / D converter 5B, A
The reference signal output from the / D converter 5A is input to the coherent integration circuits 7B and 7A, respectively.

FIG. 16 shows an outline of a processing procedure of the pulse compression processing system 18.

In the coherent integration circuits 7A and 7B, discrete Fourier transform processing of L points is performed on the input signal, and a frequency component of the L point of the input signal is calculated. The received signal and the reference signal converted into the frequency components by the coherent integration circuits 7B and 7A are input to the correlation circuit 8.

The correlation circuit 8 multiplies each frequency component of the received signal and the reference signal by the following equation (2), and outputs the result.

F _k = f _{t, k} f ^* _{r, k} (2)

Note that f _k is _k output from the correlation circuit 8.
Signal component of the second cell, f _{t, k} component of the k-th cell of the Fourier transform of the received signal signal, f _{r, k} component of the k-th cell of the Fourier transformed signal for transmission signal, f ^* is It is a conjugate signal of the complex signal _{fr, k} .

The output signal from the correlation circuit 8 is input to a coherent integration circuit 10. Coherent integration circuit 10
Then, inverse Fourier transform processing of L points is performed on the input signal. If the target actually exists at the distance cτ / 2 (c: speed of light, τ: delay time from transmission to reception), the signal transmitted by the transmitting antenna 1 is reflected to the target and delayed by τ to the receiving antenna. 3 is received.

By performing an inverse Fourier transform process by the coherent integration circuit 10, a pulse compression process is performed, and a peak is detected at a delay time τ. The target distance for L points is measured for each distance resolution calculated by the following equation (3) based on the output signal from the coherent integration circuit 10.

ΔR = c / 2B (3)

Note that δR is the distance resolution, c is the speed of light, and B is the transmission band.

The signal output from the pulse compression processing system 18 is input to the target detection processing system 11. Target detection processing system 1
In 1, a threshold is given in advance based on a false alarm probability that the receiver noise is erroneously determined as a target signal, and a signal component exceeding the threshold is determined as a target.

Based on the output signal from the coherent integration circuit 10, for each distance measured with the resolution represented by the equation (2), the threshold is compared with the signal component output as a result of performing the pulse compression processing. , A target is determined at a distance corresponding to a signal component exceeding the threshold.

FIG. 17 shows a radar handbook (Rada).
r Handbook).

In FIG. 17, reference numeral 17 denotes a coding filter for generating a transmission signal by adjusting the frequency component of an input impulse signal, and reference numeral 18 denotes a correlation processing with a reference signal having a conjugate of each frequency component of the transmission signal as a frequency component. And a matched filter that performs pulse compression processing.

Further, Japanese Patent Application Laid-Open No. 8-313624 describes a radar apparatus which realizes high-speed processing by reducing the distance resolution by limiting the frequency band when performing pulse compression. I have.

[0034]

In the conventional transmitting and receiving apparatus as described above, the search range is determined by the cycle L of the random signal set for the purpose of lowering the target radar function. Therefore, when L is large, the pulse compression processing is performed even in a distance range longer than the maximum detection distance in which the target cannot be actually detected due to the limit of the reflected power from the target, and the calculation amount is unduly increased. There was a problem.

Further, in the radar device described in Japanese Patent Application Laid-Open No. 8-313624, the processing speed is increased by limiting the frequency band at the time of performing the pulse compression. There is a problem that the distance measurement accuracy is deteriorated.

The present invention has been made in order to solve the above-mentioned problems, and a transmission / reception that can perform pulse compression processing at high speed by restricting a range to be referred to without lowering the resolution. The aim is to obtain a device.

[0037]

According to a first aspect of the present invention, there is provided a transmitter / receiver for generating a signal whose transmission frequency band is switched at a predetermined time interval, and for targeting a radio wave based on the generated signal. A transmitting antenna that irradiates toward the target, a receiving antenna that receives a signal generated by reflecting the radio wave to a target, a band limiter for the received signal, a receiver that performs phase detection, and an output from the transmitter. A first A / D converter for converting the converted analog signal into a digital signal, a second A / D converter for converting an analog signal output from the receiver into a digital signal, and the first A / D converter.
A first coherent integration circuit that performs a Fourier transform on an output signal of the A / D converter, a second coherent integration circuit that performs a Fourier transform on an output signal of the second A / D converter, and the transmitter A correlation circuit that multiplies each frequency component of a signal that has been subjected to Fourier transform on a signal output from a signal subjected to Fourier transform and a signal that has been subjected to Fourier transform on a received signal, and a received signal component from an area to be referred to among output signals of the correlation circuit. And a third coherent integration circuit for performing an inverse Fourier transform on an output signal from the band-pass filter.

According to a second aspect of the present invention, there is provided a transmitting / receiving apparatus comprising:
The band-pass filter is configured by a plurality of second band-pass filters corresponding to each of the divided regions that allows only a reception signal component from a region obtained by dividing the region to be referred to into a plurality of regions; Is constituted by a plurality of fourth coherent integration circuits for performing an inverse Fourier transform on each output signal of the plurality of second band-pass filters.

According to a third aspect of the present invention, there is provided a transmitting / receiving apparatus comprising:
The band-pass filter passes only a received signal component from an arbitrary region to be referred which does not start from a distance of zero, from an output signal of the correlation circuit.

According to a fourth aspect of the present invention, there is provided a transmitting / receiving apparatus comprising:
A plurality of second band-pass filters corresponding to the respective divided regions, wherein the band-pass filter passes only received signal components from a region obtained by dividing an arbitrary region to be referred to which does not start from the distance zero into a plurality of regions; , And the third coherent integration circuit includes a plurality of fourth coherent integration circuits that perform an inverse Fourier transform on each output signal of the plurality of second bandpass filters.

According to a fifth aspect of the present invention, there is provided a transmitting / receiving apparatus comprising:
The band-pass filter includes first and second band-pass filters that set a distance range to be referred from a trade-off of a maximum value of deterioration of a signal-to-noise power ratio determined from a shape loss of the filter, and The coherent integration circuit includes fourth and fifth coherent integration circuits for performing an inverse Fourier transform on each output signal of the first and second bandpass filters.

According to a sixth aspect of the present invention, there is provided a transmitting / receiving apparatus comprising:
The bandpass filter sets a region where an unnecessary signal having a large power is received as a cutoff region.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A transmitting and receiving apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a transmitting / receiving apparatus according to Embodiment 1 of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, a transmitting antenna 1, a transmitter 2, a receiving antenna 3, a receiver 4, and A / D converters 5A and 5A
B, the coherent integration circuits 7A and 7B, the correlation circuit 8, the coherent integration circuit 10, and the target detection processing system 11 are the same as those in the related art.

In FIG. 1, reference numeral 9 denotes a band-pass filter that passes only a received signal component from a region to be referred to. Reference numeral 6 denotes a pulse compression processing system that performs pulse compression processing only on a reception signal from a distance range to be referred to using the bandpass filter 9.

Next, the operation of the transmitting / receiving apparatus according to the first embodiment will be described with reference to the drawings.

For the purpose of paralyzing the target radar function, a radio wave is emitted using the transmission antenna 1 and the transmitter 2 as in the prior art. The radio wave reflected by the target is received by the receiving antenna 3 and processed in the same manner as in the related art, and the correlation circuit 8 outputs a signal obtained by multiplying the received signal by the reference signal.

The bandpass filter 9 sets a distance range to be referred to based on the maximum detection distance and the like, and then performs a pulse compression process only on a received signal from the region to be referred to.

In order to extract only the received signal component from the region to be referred to based on the relationship between the entire region calculated by the conventional method and the region to be referred to, the output signal from the correlation circuit 8 is converted into a band having the characteristics shown in FIG. Input to the pass filter 9.

When the number of cells in the range area to be referred to is K, the point j0 = L / K is set as the number of filters of the band-pass filter 9. Since it is sufficient to perform the pulse compression processing only for K cells, the output signal of the band-pass filter 9 is sampled at intervals of j0 cells, and the coherent integration circuit 10 performs the inverse FFT processing of K points.

Therefore, when the input signals from the correlation circuit 8 are S′1, S′2,..., S′L, the input signal from the correlation circuit 8 and the output signal S ″ 1,
The relationship among S ″ 2,..., S ″ K is as shown in FIG.

In the first embodiment, since the inverse FFT processing at point L, which has been performed in the conventional coherent integration circuit 10, is performed by the inverse FFT processing at point K (K <L), the calculation load is reduced. I have.

Embodiment 2 Embodiment 2 A transmitting / receiving apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 4 is a block diagram showing a configuration of the transmitting / receiving apparatus according to Embodiment 2 of the present invention.

In FIG. 4, a transmitting antenna 1, a transmitter 2, a receiving antenna 3, a receiver 4, and A / D converters 5A and 5A
B, coherent integration circuits 7A and 7B, and correlation circuit 8
Is the same as in the first embodiment.

Further, in the figure, 9A, 9B and 9C are band-pass filters, 10A, 10B and 10C are coherent integration circuits, and 11A, 11B and 11C are target detection processing systems. Further, the reference numeral 12 divides an area to be referred to into a plurality of areas, and prepares a band-pass filter prepared for each area, which only passes a received signal component from the area, thereby shortening the operation time of the pulse compression processing. And a pulse compression processing system.

Next, the operation of the transmitting / receiving apparatus according to the second embodiment will be described with reference to the drawings.

For the purpose of paralyzing the target radar function, a radio wave is emitted using the transmission antenna 1 and the transmitter 2 as in the first embodiment. The radio wave reflected by the target is received by the receiving antenna 3 and processed in the same manner as in the first embodiment. In the pulse compression processing system 12, the correlation circuit 8 outputs a signal obtained by multiplying the received signal and the reference signal. You.

The region to be referred to is divided by the number of bandpass filters, and each region is assigned to bandpass filters 9A, 9B,..., 9C as shown in FIG.

FIG. 5 shows a situation where an area to be referred to is divided into M parts.

Each band pass filter has 9A, 9B,.
, 9C, the weight is adjusted so that only the received signal from the assigned area is passed. At this time, the characteristics are as shown in FIG.

FIG. 6 shows an example of the characteristics of the bandpass filter in the area k (center cell mk).

The bandpass filters 9A, 9B,..., 9
C performs processing according to the following equations (4) and (5). Note that i of Σ is i = 1 to j0.

S ″ _l = Σω _i S ′ _{(l−1) j0 + i} (4)

Ω _i = ω _{0, i} exp [−j2π (m _k ) / L] (5)

[0065] Incidentally, S _"l is l-th sample of the signal of the output signal of the band-pass filter 9, S _'i is i range cell th signal of the input signal of the band-pass filter 9, j0 filter number of the band-pass filter 9 , omega _{0, i} is a weighting for adjusting the characteristics of the bandpass filter 9, the m _k is the center range cell k-th band-pass filter 9. Further, the formula (4)
The i of １〜 is i = 1 to j0.

The band pass filters 9A, 9B,..., 9
The output signals of the C
A, 10B,..., 10C. The coherent integration circuits 10 (10A, 10B,..., 10C) perform a pulse compression process using an inverse FFT.

At this time, in each area, since the pulse compression processing is performed on the area corresponding to the K / M cells, the number of inverse Fourier transform in the coherent integration circuits 10A, 10B,. ing. In the first embodiment, the inverse Fourier transform of the K point is performed in the coherent integration circuit 10, so that the second embodiment
Is the score of the inverse Fourier transform that is smaller.

The transmitting / receiving apparatus according to the second embodiment further divides a region to be referred to more finely and performs a pulse compression process for each region. Therefore, the inverse of the coherent integration circuits 10A, 10B,. The number of points in the Fourier transform is reduced, and the load on the calculation amount is reduced.

Embodiment 3 Embodiment 3 A transmitting / receiving apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 7 is a block diagram showing a configuration of the transmitting / receiving apparatus according to Embodiment 3 of the present invention.

In FIG. 7, a transmitting antenna 1, a transmitter 2, a receiving antenna 3, a receiver 4, and A / D converters 5A and 5A
B, coherent integration circuits 7A and 7B, correlation circuit 8, coherent integration circuit 10, and target detection processing system 11,
This is the same as the first embodiment.

In the same figure, reference numeral 9 denotes a band-pass filter having different characteristics, and reference numeral 13 denotes a pulse compression process which performs a pulse compression process only on received signals from a range to be referred to before and after a predetermined distance. System.

Next, the operation of the third embodiment will be described. For the purpose of paralyzing the target radar function, a radio wave is emitted using the transmission antenna 1 and the transmitter 2 as in the first embodiment. The radio wave reflected on the target is received by the receiving antenna 3 and processed in the same manner as in the first embodiment. In the pulse compression processing system 13, a signal obtained by multiplying the received signal and the reference signal from the correlation circuit 8 is output. .

The signal output from the correlation circuit 8 is input to the band pass filter 9. The band-pass filter 9 is configured to pass only received signals from a range to be referred before and after a predetermined distance as a center. Bandpass filter processing is performed according to the following equations (6) and (7). Note that Σ
I is i = 1 to j0.

S ″ _l = Σω _i S ′ _{(l−1) j0 + i} (6)

Ω _i = ω _{0, i} exp [−j2π (m) / L] (7)

S ″ _l is the signal of the first sample of the output signal of the band-pass filter 9, S ′ _i is the signal of the i-th cell of the input signal of the band-pass filter 9, and j 0 is the number of filter points of the band-pass filter 9 , Ω _{0, i} are weights for adjusting the characteristics of the band-pass filter 9, and m is the center range cell of the band-pass filter 9. Also, i of Σ in the equation (6)
Is i = 1 to j0.

The transmitting / receiving apparatus according to the third embodiment is configured to perform the pulse compression processing only on a region to be referred to which does not necessarily start from a distance of zero.
The number of points of the inverse Fourier transform in the coherent integration circuit 10 is reduced, and the load of the calculation amount is reduced.

Embodiment 4 Embodiment 4 A transmitting and receiving apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings.
FIG. 8 is a block diagram showing a configuration of the transmitting / receiving apparatus according to Embodiment 4 of the present invention.

In FIG. 8, a transmitting antenna 1, a transmitter 2, a receiving antenna 3, a receiver 4, and A / D converters 5A and 5A
B, coherent integration circuits 7A and 7B, correlation circuit 8, coherent integration circuits 10A, 10B,.
And target detection processing systems 11A, 11B,..., 11C
Is the same as in the second embodiment.

In the same figure, 9A, 9B,.
.., 9C are band-pass filters having different characteristics, and 14 divides a region to be referred before and after about a predetermined distance into a plurality of regions, and performs pulse compression processing for each region in the same manner as in the second embodiment. This is a pulse compression processing system.

Next, the operation of the fourth embodiment will be described. For the purpose of paralyzing the target radar function, a radio wave is emitted using the transmitting antenna 1 and the transmitter 2 as in the second embodiment. The radio wave reflected on the target is the receiving antenna 3
, And the same processing as in the second embodiment is performed, and a signal obtained by multiplying the received signal by the reference signal is output from the correlation circuit 8.

The signals output from the correlation circuit 8 are input to bandpass filters 9A, 9B,..., 9C. The region to be referenced is divided by the number of bandpass filters, and each region is assigned to a bandpass filter. The weight of each band-pass filter is adjusted so that only the received signal from the assigned area passes. When the center cell of the range passing m cells is used, the band-pass filter performs processing according to the following equations (8) and (9). Note that i of Σ is i = 1 to 1.
j0.

S ″ _l = Σω _i S ′ _{(l−1) j0 + i} (8)

Ω _i = ω _{0, i} exp [−j2π (m + m _k ) / L] (9)

S ″ _l is the signal of the first sample of the output signal of the band-pass filter 9, S ′ _i is the signal of the i-th cell of the input signal of the band-pass filter 9, and j 0 is the number of filter points of the band-pass filter 9 , omega _{0, i} is a weighting for characteristic adjusting the bandpass filter 9, m is the center range cell in the region to be referenced, m _k in the center range cell when a reference m cells of the k-th band-pass filter 9 There is also
I of Σ in Expression (8) is i = 1 to j0.

The transmitting / receiving apparatus according to the fourth embodiment has a configuration in which pulse compression processing is performed only on a region to be referred to which does not necessarily start from a distance of zero, and the region to be referred to is further divided into smaller regions. Since the pulse compression processing is performed for each region, the number of inverse Fourier transforms in the coherent integration circuits 10A, 10B, and 10C is reduced, and the load of the calculation amount is reduced.

Embodiment 5 Embodiment 5 A transmitting / receiving apparatus according to Embodiment 5 of the present invention will be described with reference to the drawings.
FIG. 9 is a block diagram showing a configuration of a transmitting / receiving apparatus according to Embodiment 5 of the present invention.

In FIG. 9, a transmitting antenna 1, a transmitter 2, a receiving antenna 3, a receiver 4, and A / D converters 5A and 5A
B, coherent integration circuits 7A and 7B, and correlation circuit 8
Is the same as in the first embodiment.

In the same figure, 9A and 9B are bandpass filters, 10A and 10B are coherent integration circuits,
11A and 11B are target detection processing systems, and 15 is a trade-off between the range of the area covered by the two types of band-pass filters 9A and 9B and the maximum value of deterioration of the signal-to-noise power ratio determined by the shape loss of the band-pass filters. This is a pulse compression processing system characterized in that a distance range to be referred to is set.

Next, the operation of the fifth embodiment will be described. For the purpose of paralyzing the target radar function, a radio wave is emitted using the transmission antenna 1 and the transmitter 2 as in the first embodiment. The radio wave reflected by the target is received by the receiving antenna 3, processed in the same manner as in the first embodiment, and the correlation circuit 8 outputs a signal obtained by multiplying the received signal by the reference signal.

The signal output from the correlation circuit 8 is input to two types of bandpass filters 9A and 9B. Each of the band-pass filters 9A and 9B is assigned a divided area to be referred to.

At this time, the size of the area to be referred to is
Is set with reference to the maximum value d of the deterioration of the signal-to-noise power ratio determined from the shape loss of the band-pass filter shown in FIG. When two types of band-pass filters 9A and 9B are used to pulse-compress a received signal from a region to be referred to, the maximum value of the deterioration of the signal-to-noise power ratio is d. This d increases as the area to be referred to is increased.

Therefore, the relationship between the size of the region to be referred to and the value of d is calculated, and the size of the region to be referred to is set from the trade-off.

The transmitting / receiving apparatus according to the fifth embodiment has two
The distance range to be referred to is set from the trade-off between the range of the area covered by the bandpass filters 9A and 9B and the maximum value of the deterioration of the signal-to-noise power ratio determined from the shape loss of the bandpass filters. In addition, it is possible to perform a pulse compression process on a received signal from a maximum range that is possible within an allowable range of deterioration of the signal-to-noise power ratio.

Embodiment 6 FIG. A transmitting / receiving apparatus according to Embodiment 6 of the present invention will be described with reference to the drawings.
FIG. 11 is a block diagram showing a configuration of a transmitting / receiving apparatus according to Embodiment 6 of the present invention.

In FIG. 11, a transmitting antenna 1, a transmitter 2, a receiving antenna 3, a receiver 4, and A / D converters 5A and 5A
B, coherent integration circuits 7A and 7B, correlation circuit 8, coherent integration circuit 10, and target detection processing system 11,
This is the same as the first embodiment.

In the same figure, reference numeral 9 denotes a band-pass filter having different characteristics, and reference numeral 16 denotes a signal-to-undesired-signal power ratio by using the band-pass filter 9 having a cut-off region in which a high-power unnecessary signal is received. Is a pulse compression processing system characterized in that

Next, the operation of the sixth embodiment will be described. For the purpose of paralyzing the target radar function, a radio wave is emitted using the transmission antenna 1 and the transmitter 2 as in the first embodiment. The radio wave reflected by the target is received by the receiving antenna 3, processed in the same manner as in the first embodiment, and the correlation circuit 8 outputs a signal obtained by multiplying the received signal by the reference signal.

The signal output from the correlation circuit 8 is input to the band pass filter 9. In the band-pass filter 9, as shown in FIG. 12, the weight of the band-pass filter is adjusted so as to have a characteristic in which a region where an unnecessary signal having a large power is received is a cut-off region.

The transmitting / receiving apparatus according to the sixth embodiment uses band-pass filter 9 having a characteristic that a region where an unnecessary signal having a large power is received is a cut-off region.
Unwanted signals are suppressed, the signal-to-unwanted signal power ratio is improved, and the target detection performance is improved.

[0101]

As described above, the transmitting / receiving apparatus according to the first aspect of the present invention includes a transmitter for generating a signal whose transmission frequency band is switched at a constant time interval, and a radio wave based on the generated signal. A transmitting antenna that irradiates toward the target, a receiving antenna that receives a signal generated by reflecting the radio wave to the target, a band limiting for the received signal, a receiver that performs phase detection, and A first A / D converter for converting an output analog signal to a digital signal, a second A / D converter for converting an analog signal output from the receiver to a digital signal,
A first coherent integration circuit for performing a Fourier transform on an output signal of the first A / D converter; and a second A / D converter.
Second performing a Fourier transform on the output signal of the / D converter
A coherent integration circuit, a correlation circuit that multiplies each frequency component of a signal that has been subjected to Fourier transform on a signal output from the transmitter and a signal that has been subjected to Fourier transform on a received signal, and an output signal of the correlation circuit. ,
Since a band-pass filter that passes only a received signal component from a region to be referred to and a third coherent integration circuit that performs an inverse Fourier transform on an output signal from the band-pass filter are provided, the processing speed is increased. It has the effect of being able to do so.

The transmitting and receiving apparatus according to claim 2 of the present invention
As described above, the band-pass filter is configured by a plurality of second band-pass filters corresponding to each of the divided regions, which allows only the reception signal component from the region obtained by dividing the region to be referred to into a plurality of regions. Since the third coherent integration circuit is composed of a plurality of fourth coherent integration circuits for performing an inverse Fourier transform on each output signal of the plurality of second band-pass filters, the processing can be speeded up. This has the effect that it can be realized.

A transmitting / receiving apparatus according to a third aspect of the present invention comprises:
As described above, since the band-pass filter passes only the reception signal component from an arbitrary region to be referred to that does not start from the distance of zero in the output signal of the correlation circuit, it is possible to realize high-speed processing. It has the effect of being able to.

A transmitting / receiving apparatus according to a fourth aspect of the present invention comprises:
As described above, the band-pass filter allows only a received signal component from an area obtained by dividing an area to be referred to that does not start from the distance zero into a plurality of areas,
A plurality of second bandpass filters corresponding to the respective divided regions, wherein the third coherent integration circuit includes:
Since it is composed of a plurality of fourth coherent integration circuits for performing an inverse Fourier transform on each output signal of the plurality of second band-pass filters, it is possible to achieve an effect of realizing high-speed processing.

A transmitting / receiving apparatus according to claim 5 of the present invention is
As described above, the band-pass filter includes the first and second band-pass filters in which a distance range to be referred to is set based on a trade-off of a maximum value of deterioration of a signal-to-noise power ratio determined from a shape loss of the filter. , The third
Is constituted by fourth and fifth coherent integration circuits for performing an inverse Fourier transform on each output signal of the first and second band-pass filters. There is an effect that a received signal from a wide area can be pulse-compressed within the power ratio deterioration range.

The transmitting and receiving apparatus according to claim 6 of the present invention provides:
As described above, since the band-pass filter sets a region where an unnecessary signal having a large power is received as a cutoff region, it is possible to improve a signal-to-unwanted signal power ratio.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transmission / reception apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating characteristics of a bandpass filter of the transmitting and receiving apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing sampling of a bandpass filter of the transmitting and receiving apparatus according to Embodiment 1 of the present invention.

FIG. 4 is a block diagram showing a configuration of a transmitting / receiving apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a diagram showing allocation of a range area to be referred to by the transmitting and receiving apparatus according to Embodiment 2 of the present invention.

FIG. 6 is a diagram showing a state of preprocessing of inverse Fourier transform by a transmitting and receiving apparatus according to Embodiment 2 of the present invention.

FIG. 7 is a block diagram showing a configuration of a transmitting / receiving apparatus according to Embodiment 3 of the present invention.

FIG. 8 is a block diagram showing a configuration of a transmitting and receiving apparatus according to Embodiment 4 of the present invention.

FIG. 9 is a block diagram showing a configuration of a transmitting and receiving apparatus according to Embodiment 5 of the present invention.

FIG. 10 is a diagram illustrating a relationship between allocation of a range region and deterioration of a signal-to-noise power ratio by a transmission / reception apparatus according to Embodiment 5 of the present invention.

FIG. 11 is a block diagram showing a configuration of a transmitting and receiving apparatus according to Embodiment 6 of the present invention.

FIG. 12 is a diagram illustrating characteristics of a band-pass filter of a transmitting / receiving apparatus according to Embodiment 6 of the present invention.

FIG. 13 is a block diagram showing a configuration of a conventional transmitting / receiving apparatus.

FIG. 14 is a diagram illustrating a state of division of a transmission band by a conventional transmission / reception apparatus.

FIG. 15 is a flowchart showing a transmission signal generation operation by a conventional transmission / reception device.

FIG. 16 is a diagram illustrating an outline of a pulse compression process performed by a conventional transmission / reception device.

FIG. 17 is a diagram showing a configuration of a pulse compression processing system of a conventional transmitting / receiving apparatus.

[Explanation of symbols]

1 transmitting antenna, 2 transmitter, 3 receiving antenna, 4
Receiver, 5A, 5BA / D converter, 6 pulse compression processing system, 7A, 7B coherent integration circuit, 8 correlation circuit, 9, 9A, 9B, 9C band pass filter, 10,
10A, 10B, 10C Coherent integration circuit, 1
1, 11A, 11B, 11C Target detection processing system, 12
Pulse compression processing system, 13 pulse compression processing system, 14 pulse compression processing system, 15 pulse compression processing system, 16 pulse compression processing system.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshio Kosuge 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Yasushi Hoshina 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd. (72) Inventor Mitsuru Tanuma 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 5J070 AB01 AC02 AC06 AD02 AE04 AH04 AH31 AH34 AH35 AH40 AH50 AK22 AK28 AK40 AL01 BH01

Claims (6)

[Claims] 1. A transmitter that generates a signal whose transmission frequency band is switched at regular time intervals, a transmission antenna that irradiates a radio wave to a target based on the generated signal, and a radio wave that reflects to the target. A receiving antenna for receiving a signal generated by the above-described method, a receiver for performing band limitation and phase detection on the received signal, and a first A / D for converting an analog signal output from the transmitter to a digital signal A converter, a second A / D converter for converting an analog signal output from the receiver into a digital signal, and a first coherent for performing a Fourier transform on an output signal of the first A / D converter An integrating circuit; a second coherent integrating circuit for performing Fourier transform on an output signal of the second A / D converter; and a Fourier transform for a signal output from the transmitter. A correlation circuit that performs multiplication on each frequency component of the signal subjected to the Fourier transform on the signal subjected to the Fourier transform, and a band-pass filter that passes only a reception signal component from a region to be referred to, among output signals of the correlation circuit. A third coherent integration circuit for performing an inverse Fourier transform on an output signal from the band-pass filter. 2. The band-pass filter includes a plurality of second band-pass filters corresponding to each of the divided regions, which passes only reception signal components from the region into which the region to be referred to is divided into a plurality of regions. The third coherent integration circuit is configured by a plurality of fourth coherent integration circuits that perform an inverse Fourier transform on each output signal of the plurality of second bandpass filters. 2. The transmitting / receiving device according to claim 1. 3. The transmission / reception according to claim 1, wherein the band-pass filter passes only a reception signal component from an arbitrary region to be referred to which does not start from a distance of zero, from the output signal of the correlation circuit. apparatus. 4. The band-pass filter according to claim 1, wherein said band-pass filter passes only reception signal components from a region obtained by dividing an arbitrary region to be referred to that does not start from the distance of zero into a plurality of regions. And the third coherent integration circuit is configured by a plurality of fourth coherent integration circuits that perform an inverse Fourier transform on each output signal of the plurality of second bandpass filters. The transmission / reception device according to claim 3, wherein: 5. The band-pass filter comprises first and second band-pass filters in which a distance range to be referred to is set from a trade-off of a maximum value of deterioration of a signal-to-noise ratio determined by a shape loss of the filter. The third coherent integration circuit includes the first and second coherent integration circuits.
2. The transmission / reception apparatus according to claim 1, further comprising fourth and fifth coherent integration circuits for performing an inverse Fourier transform on each output signal of said band-pass filter. 6. The transmitting / receiving apparatus according to claim 1, wherein the band-pass filter sets a region where an unnecessary signal having a large power is received as a cut-off region.