JPH05157836A - Pulse compression device and its application device - Google Patents

Abstract

PURPOSE:To generate a compressed pulse signal in a small constitution by implementing the electrical/photo conversion of the received signal, and implementing the photo-electric conversion of the guided optical signal through the optical fiber bundle having the respective length corresponding to the pitch point of each cycle of the signal. CONSTITUTION:The received signal 10A is supplied to an electric/photo conversion circuit 111 to make the optical signal 111A. In a guided optical circuit 112, the length of the respective fibers is set to the length corresponding to the pitch point of each cycle of the non-equivalence cycle where the transmitted signal is converted in the inversed wave pattern, a fo respective fibers, the optical signal 111A is supplied to an input terminal 112a, and the guided optical signal 112A is emitted from an output terminal 112b. The guided optical signal 112A is received by a photo/electric conversion circuit 113, and the signal whose voltage has the value corresponding to three kinds of intensities of the respective optical signals in the guided optical signal 112A is obtained as the compressed signal 11A. Thus, the device is capable of downsized constitution and stable delay synthesis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse compression device and a utilization device such as a pulse compression radar device for detecting a target using the pulse compression device.

[0002]

2. Description of the Related Art A device of this type is a transmission pulse having a wide pulse width in which transmission frequency components are unequalized or coded in order to increase detection capability in a reflection type detection device or a transmission type detection device. To detect,
By demodulating each cycle component of the received pulse obtained as a reflected wave or a transmitted wave according to the unequalization cycle or coding cycle at the time of transmission, it is possible to compress to a narrow pulse width and obtain a detection signal with a large amplitude value. Even if the power peak value on the transmitting side is small, it is possible to obtain the effect of increasing the detection distance.

As the reflection type detection device, there are a radar for a ship which detects a land condition, a navigation condition of a ship and the like by a reflected wave, and a radar for an underground survey which detects a condition of a buried object under the ground surface, a condition of a stratum change and the like. Further, as a passage type detection device, there is a borehole radar or the like that detects the state of buried objects and the state of formation change in an underground route between required points by means of passing waves.

Among such pulse compression methods, there are stepwise frequency modulation format, linear frequency modulation format, etc. by the inequality cycle, and code phase modulation format, code carrier modulation by the coding cycle. There are formats, etc.

The stepwise frequency modulation type will be described with reference to FIG. 11. As shown in FIG.
Is set as the pitch point of each cycle of the inequality cycle, and the frequency is sequentially increased to the higher frequencies f1, f2, f3, and f4.
・ A signal with a wide time width T changed like f5
As in (B), it has a series of frequency modulations and a pulse width T
A signal having a low amplitude value is transmitted as a transmission pulse, and the received pulse obtained as a detection wave has a frequency modulation similar to that at the time of transmission. Therefore, as shown in (D), After the filters F1, F2, F3, F4, and F5 for the respective frequencies f1 to f5 in the modulation of 1 are provided and the signal for each unit time Ta is detected, as shown in (C),
Unit time width T for each signal corresponding to each frequency f1 to f5
The pulse width T is given to the combining circuit M through the delay lines D1, D2, D3, D4, and D5 for providing the delay time which is increased by sequentially reversing the time of a, as shown in (E). A compressed pulse P having a high amplitude value in which the amplitude values are concentrated in the central portion of the time width 2T that is twice as long as the pulse width and the pulse width is narrowed.

The linear frequency modulation type is also called chirp modulation, and will be described with reference to FIG.
As in (a), a time-frequency relationship changes linearly by Δf over a wide pulse width T, and a frequency-modulated signal in which the intervals of each cycle are unequal is Since a signal having the same frequency modulation as that at the time of transmission is obtained for the reception pulse obtained as a detection wave by transmitting as a transmission pulse with a low amplitude value, as shown in (c), the time / frequency relationship in the modulation at the time of transmission is shown. By giving to a network having a reception characteristic having a frequency / time relationship opposite to,
The compressed pulse P has a high amplitude value in which the amplitude value is concentrated in the central portion of the time width 2T which is twice the pulse width T, and the pulse width is narrowed. In this form, the points corresponding to the top or bottom of the waveform of each cycle can be viewed as the pitch points of each cycle of the unequalized cycle.

The code phase modulation type is also called coded pulse modulation, and will be described with reference to FIG.
As shown in (b), each 1-cycle signal having a constant period Tb is a pulse signal of 1 unit, and in each pulse signal of 1 unit, the phase starting from the 0 ° position is “+”, and 1
The one starting from the 80 ° position is coded as "-", and for example, a phase-modulated wave such as (b) having the coded cycle of (ii) is transmitted as a transmission pulse with a low amplitude value and is used as a detection wave. A signal having the same phase modulation as that at the time of transmission is obtained for the obtained reception pulse. Therefore, when this signal is phase-detected, a detection signal corresponding to the phase modulation at the time of transmission is obtained as shown in (c), As shown in (d), the delay line DL is provided with taps at each time corresponding to the period Tb of each unit pulse at the time of transmission, and each tap point is given a "-" sign at a point reverse to the encoding at the time of transmission. Since the signal of the phase corresponding to the signal appears, the signal of this part is inverted by the phase inversion circuit I and then given to the combining circuit M and combined, so that the pulse width T is doubled as shown in (e). Amplitude values are concentrated in the central part of the time width 2T It has a width value, and is intended to obtain the compressed pulse P having a pulse width is narrowed. In the case of this format, the points corresponding to each cycle can be regarded as the pitch points of each cycle of the encoding cycle.

In the code carrier modulation type, the transmitting side is
In the stepwise frequency modulation type of FIG. 11, the frequencies f1 to f5 of the signal of (B) are changed to carrier signals of the same frequency, and the carrier wave at each unit time Ta is 1 in the code phase modulation type of FIG. Similarly to the unit pulse, the signal modulated by the cycle in which each unit pulse is encoded is transmitted as a transmission pulse with a low amplitude value, and on the receiving side,
Since the received signal is a carrier signal, the phase detection results in a detection signal similar to (c) in the code phase modulation type of FIG. 13, and the subsequent signals are shown in FIG.
A similar compressed pulse P is obtained by processing the cycle Tb in the code phase modulation format of No. 3 instead of each unit time Ta. In this format, each unit time T
The point corresponding to a can be seen as the pitch point of each cycle of the encoding cycle.

The construction of the above-mentioned prior art is described in [Reference] Showa 5
It is disclosed in "Electronic Communication Series-Radar Technology (Part 2)" issued by the Institute of Electronics and Communication Engineers, June 2004.

[0010]

In the above-described pulse compression structure, the compressed pulse P is not distorted, and the side pulses SP1 and SP2 generated on both sides are made as small as possible to obtain good characteristics. In the modulation type, since it is necessary to increase the number of changes of the frequencies f1 to f5 to the number of steps, that is, the number of steps to at least 30 steps or more, the delay lines D1 to D5 also increase, and the delay lines D1 to D5 also increase. Since the configuration of the line portion becomes enormous, there is a disadvantage that a practical one has not been obtained.

In the case of the linear frequency modulation type, similarly, it is necessary to set the number of cycles having a frequency change, that is, the number of steps to 30 steps or more, and the time / frequency relationship in modulation at the time of transmission. If a circuit network having a reception characteristic having a frequency / time relationship opposite to that of the above is configured with a large number of steps and a large number of filters, the size becomes enormous, and a practical one cannot be obtained. However, in order to avoid this, if the configuration is made by a matched filter by arithmetic processing, there is an inconvenience that the detection time cannot be displayed immediately on the spot for the detection signal of a very short distance.

In the code phase modulation format / code carrier modulation format, similarly, a coding number of about 50 unit pulses, that is, the number of steps is required, and like the stepwise frequency modulation format, There is an inconvenience that the delay line DL has an enormous size and no practical one has been obtained. Therefore, there is a problem that it is desired to provide a product that solves such inconvenience.

[0013]

According to the present invention, a signal having a wide pulse width by the above-described inequality cycle or encoding cycle, that is, a signal having a narrow pulse width by pulse-compressing a compressed signal, that is, In a pulse compression apparatus for obtaining a compressed pulse signal, optical signal means for obtaining an optical signal obtained by electrical / optical conversion of the above-mentioned compressed signal, and each of said optical signal corresponding to a pitch point of each cycle of the above-mentioned compressed signal A light guide means for giving an optical signal obtained from each other end to each one end of each wire of the outer peripheral reflection type light guide thin wire having a length, as each light guide signal;
A compression means for obtaining the compressed pulse signal based on a signal obtained by optically / electrically converting each of the above-mentioned light guide signals is provided, and in addition, a reflection type detection device, a passage type detection device, etc. are provided by using this pulse compression device. With the configuration, the above problems can be solved.

[0014]

EXAMPLES Examples will be described below with reference to the drawings. [First Embodiment] As a first embodiment, a radar for detecting an underground buried object using a transmission pulse of the linear frequency modulation type explained in FIG. An embodiment of the detection device will be described with reference to FIG.

In FIG. 1, a transmission signal 2A obtained by amplifying a linear frequency modulation signal 1A generated by the frequency modulation circuit 1 as shown in FIG.
To the transmitting antenna 3 provided on the ground surface 4,
The detection device 100 is moved while transmitting the transmission electromagnetic wave 6 to the ground 5 at a predetermined detection repetition cycle.

Here, the number of cycles of frequency change in the transmission signal 2A, that is, the number of steps is actually selected to be at least 30 steps or more, but the number of steps is made smaller than the actual number for convenience of illustration.

The received signal 9A obtained by receiving the reflected electromagnetic wave 8 from the underground buried objects 7A, 7B and 7C by the receiving antenna 9 provided on the ground surface 4 is amplified by the receiving and amplifying circuit 10 to a required amplitude value. Then, the reception signal 10A of FIG. 2 is obtained.

Reflected signals 10a and 10 in the received signal 10A
b.10c are reception signals corresponding to the reflected electromagnetic waves from the underground buried objects 7A, 7B, 7C, and pulses of a length corresponding to a wide pulse width T in the transmission pulse 2A as shown in FIG. 12B. It can be regarded as having the width TR and appearing with the steps of the inequality cycle similar to those at the time of transmission.

The received signal 10A is applied to the delay synthesizing section 11 having the structure described later to perform delay synthesizing, and the received signal 10A is pulse-compressed to obtain the compressed signal 11A shown in FIG.

Compressed signals 11a and 11 in the compressed signal 11A
b · 11c is the width of the high amplitude value in which the amplitude values are concentrated in the central portion of the pulse width TR of each reflection signal, similarly to the compressed pulse P of FIG. 12 (d). The signal is compressed into a narrow compressed pulse of.

The compressed signal 11A is given to the display processing circuit 12 to perform the required display processing.
While converting the amplitude values of 11b and 11c into luminance values,
A display signal 12A is obtained by converting each detection cycle into a signal to be displayed as one scan of raster scan display.

The display signal 12A is sent to the raster scan type display 1
3 to display a B-scope-shaped detection image.

The received signal 10A has a bias level with respect to 0 V as shown in FIG. 2 in consideration of the fact that the conversion characteristic of the electric / optical conversion circuit 111, which will be described later, is generally poor in a low voltage portion. It is preferable to keep the signal with.

It is needless to say that it is preferable to deal with the optical / electrical conversion circuit 113 described later in the same manner.

The delay synthesizing section 11 corresponds to a section for pulse-compressing and demodulating a signal of an unequalized cycle, and is constructed as shown in FIG.

In FIG. 3, an electric / optical conversion circuit 111 for giving the received signal 10A is a circuit for performing electric / optical conversion by a light emitting diode, for example, and the intensity of light corresponds to the amplitude value of each signal in the received signal 10A. Optical signal 1 with corresponding value
Obtain 11A.

The light guide circuit 112 is a bundle of a large number of outer peripheral reflection type light guide thin wires, for example, an optical fiber, in which the length of each light guide thin wire is varied according to the specific conditions described later. An optical signal 111A is provided to each light guide thin wire with one end as an input end 112a, and a light guide signal 112A that has passed through each light guide thin wire is provided as the other end with an output end 112b, and is provided to the optical / electrical conversion circuit 113.

The optical / electrical conversion circuit 113 is, for example, a circuit for performing optical / electrical conversion by a light receiving diode, and compresses a signal whose voltage has a value corresponding to the intensity of each optical signal in the light guide signal 112A into the compressed signal 11A. Is configured to obtain.

The electric / optical conversion circuit 1 is provided at the input end 112a.
Depending on the configuration of 11, the optical junction conductor CT for uniformizing the light input to each light guide thin line, for example, a distribution lens is provided as necessary, and the output end 112b is provided with an optical / electrical conversion. Depending on the configuration of the circuit 113, an optical junction conductor CR, for example, a converging lens, for converging the light output from each light guide thin line is provided as necessary.

The length of each light guiding thin wire in the light guiding circuit 112, that is, each light guiding thin wire length is conditioned as shown in FIG.

In FIG. 4, the inverse waveform (A) is a signal waveform in which the transmission signal 2A is shown in the reverse time series, and is unequal from the end point of the transmission signal 2A, that is, the start point of the inverse waveform (A). The time length t up to the top of each waveform in each cycle
1 ・ t2 ・ t3 …… tm ・ tn.

Each light guide thin wire length (B) is the time length t1, t2, t3 ... tm in the propagation velocity of light in each light guide thin wire.
The length corresponding to tn, that is, the length corresponding to the pitch point of each cycle of the inequality cycle in which the transmission signal 2A has an inverse waveform is set.

Therefore, when an optical signal 111A having a light intensity corresponding to the received signal 10A is given from one end of each light guide thin wire length (B), the other end of each light guide thin wire length (B) becomes Since each light guide signal that matches the pitch point of each cycle of the unequalization cycle is obtained and the light obtained by combining the light guide signals is supplied to the optical / electrical conversion circuit 113, the optical / electrical conversion circuit 1 is provided.
13, the same operation as the delay combining described in FIG. 12 is performed, and the reflected signal 10a.
10b and 10c are pulse-compressed compressed signals 11a and
11b and 11c can be formed and output.

[Second Embodiment] As a second embodiment, the first embodiment
An embodiment in which the signal on the bottom side of each waveform in each cycle of the inequality cycle can also contribute to pulse compression in the same configuration as the embodiment of FIG.

In FIG. 5, the portions having the same reference numerals as those in FIG. 1 have the same functions as described in the first embodiment, and the polarity reversing circuit 10X is, for example,
It is an inverting amplifier circuit, which is a signal obtained by inverting the polarity of the received signal 10A and having the same output value.
Get as A.

The delay synthesizing unit 11X has the same structure as the delay synthesizing unit 11 and has the same function as that described in the first embodiment with reference to FIG. The only difference is the condition as shown in FIG.

In FIG. 6, the inverse waveform (AX) is a signal waveform of a waveform obtained by inverting the waveform of the inverse waveform (A) in FIG.
End point of transmission signal 2A, that is, inverted waveform (AX)
From the start point of each of the inequality cycles to the wave vertices of each cycle of the inequality cycle, time lengths t1X, t2X, t3X ...
It is X.

Each light guide thin wire length (BX) is a time length t1X.t2X.t3X at the propagation velocity of light in each light guide thin wire.
The length corresponding to tmX · tnX, that is, the length corresponding to the pitch point of each cycle of the inequality cycle in which the inverse waveform of the transmission signal 2A is inverted is set.

That is, the optical / electrical conversion circuit 113 pulse-compresses the signal obtained by inverting the reflected signal 10a, 10b, 10c in the received signal 10A through another path, and outputs the compressed signal 11
Compressed signal 11XA formed on aX ・ 11bX ・ 11cX
Is output.

The synthesis output circuit 14 is, for example, a circuit for adding the amplitudes of two input signals, and the amplitude value of the compressed signal 11A obtained by the delay synthesis section 11 and the compressed signal 11XA obtained by the delay synthesis section 11X. By obtaining the combined compressed signal 14A that is added and combined with the amplitude value, the two delay combining units 11.
Each of the compressed signals 11A and 11XA obtained by 1X can be a compressed pulse signal having a narrower width, and the configuration of the second embodiment is shown in FIG. Can be expressed as

When this addition synthesis is performed, if there is a portion where the phases overlap with the side pulses generated on both sides of the compressed pulse,
Since a large side pulse is generated in that portion, each compressed signal 11A · 11XA is passed through a circuit having an integration constant of a very small time constant to smooth the side pulse portion, or a level clipping circuit for cutting a low level. It is desirable to cut the side pulse portion through and add and synthesize.

[Third Embodiment] Next, as a third embodiment, an embodiment of the underground buried object detecting radar using the transmission pulse of the code phase modulation format described with reference to FIG. 13 will be described with reference to FIG. ..

In FIG. 8, the portions having the same reference numerals as those in FIGS. 1 and 5 have the same functions as described in the first and second embodiments, and the code modulation circuit 1Y. The transmission signal 2AY obtained by amplifying the code phase modulation signal 1AY as shown in FIG. 13B generated by the power amplification circuit 2 to the required power is generated by the transmission antenna 3 provided on the ground surface 4.
Then, the transmitting antenna 3 is moved while transmitting the transmitting electromagnetic wave 6Y from the ground surface 4 to the ground 5 by applying to the antenna.

Here, the number of coding cycles in the transmission signal 2AY, that is, the number of steps is actually selected to be at least 30 steps or more, but the number of steps is smaller than the actual number for convenience of illustration.

The received signal 9AY obtained by receiving the reflected electromagnetic wave 8Y from the underground buried objects 7A, 7B and 7C by the receiving antenna 9 provided on the ground surface 4 is amplified by the receiving and amplifying circuit 10 to a required amplitude value. Then, when phase detection is performed, the received signal 1 in FIG.
0AY is obtained.

Reflected signal 10aY in received signal 10AY
Reference numerals 10bY and 10cY are reception signals corresponding to reflected electromagnetic waves from the underground buried 7A, 7B, and 7C, respectively, and a wide pulse as shown in FIG. It can be regarded as having a pulse width TR of a length corresponding to the width T and appearing with the same steps of the coding cycle as at the time of transmission.

The received signal 10AY is given to the delay synthesizing section 11 for delay synthesizing, and the inverted signal 10XAY is given to the delay synthesizing section 11X for delay synthesizing to obtain each compressed signal 11AY.
・ 11XAY is added by the synthesizing circuit 14 to obtain the synthesized compressed signal 14AY, and the reflected signals 10aY, 10bY, 10cY in the received signal 10AY are compressed pulse signals such as compressed signals 14aY, 14bY, 14cY, respectively. It is configured to output.

In the case of this embodiment, each delay synthesizing unit 11.1
When the length of each light guide thin line of the light guide circuit 112 and the light guide circuit 112X in 1X is shown in the same manner as the principle configuration when viewed from the transmission waveform of FIG. 7 described in the second embodiment, The code, the transmission waveform, and the phase detection waveform are conditioned as shown in FIG.

In FIG. 10, since the inverse waveform for the transmission type (BY) takes a time series from the end side to the start side of the transmission waveform (BY), each pitch point of the coding cycle is seen from the end side. The length of each light guiding thin line of the light guiding circuit 112 and the length of each light guiding thin line of the light guiding circuit 112X are set to the lengths shown in the figure.

The light guide strips in FIG. 10 appear to be positioned at the end point of each pitch when viewed in reverse waveform, that is, in the reverse time series, but this is because they are positioned at the start point for the following reason. become.

The reception signal subjected to delay synthesis does not enter in the reverse waveform time series as in FIG. 6, but in the same time series as the regular time series of the transmission waveform (BY) in FIG. Therefore, the position of the left end of each light guide thin line in FIG. 10, that is, FIG.
The end point of each pitch of the encoding cycle in the reverse waveform viewed from the right end side of 0 as the head corresponds to the same position as the start point of each pitch of the encoding cycle in the normal transmission waveform viewed from the left end side of FIG. After all, if the light guide thin line lengths shown in FIG. 10 are set, the delay synthesis will be performed from the start point side of each pitch of the encoding cycle.

[Modified Implementation] The present invention can be modified and implemented as follows. (1) In the case of applying to the detection device using the transmission pulse of the stepwise frequency modulation format, the signal having the outputs of the filters F1, F2, F3, F4, and F5 in FIG. 11, and each light guide thin line length of the light guide circuit 112 is configured to match the pitch point of the encoding cycle.

(2) In the configuration of the detection device using the transmission pulse of the coded phase modulation type, the delay synthesizer 11 does not detect the phase of the received signal but keeps the phase modulated signal as shown in FIG. -Input to 11X and similarly configure to obtain a compressed pulse.

(3) Contrary to FIG. 12B, the frequency change in the linear frequency modulation type is made to correspond to the transmission pulse which is changed from the high frequency to the low frequency.

(4) A transmission antenna and a reception antenna are opposed to each other with a space therebetween, and a passing wave that has passed through the medium between both antennas is received as a reception signal to detect the state in the medium. The present invention is applied to a type detecting device that uses a transmission pulse of an inequality cycle or an encoding cycle.

(5) Communication using an inequality cycle or a coding cycle as a communication element for the purpose of improving confidentiality and noise resistance, for example, data communication is transmitted as an inequality cycle or a coding cycle. Then, the present invention is applied to a communication device in which the received signal is pulse-compressed and decoded.

(6) Instead of the received signal 10A, a single pulse signal is given as a drive signal, so that the configuration of the delay synthesizing unit 11 or the delay synthesizing units 11 and 11X is unequalized or encoded. It is applied for the generation of.

(7) Depending on the number of light guiding thin lines of the light guiding circuit 112, a plurality of light emitting elements such as light emitting diodes forming the electric / optical conversion circuit 111 may be formed, or light / light converting elements may be formed.
A plurality of light-receiving elements such as light-receiving diodes that configure the electric conversion circuit 113 are configured.

(8) All the light-guiding thin wires of the light-guiding circuit 112 are not bundled into one bundle but are divided into a plurality of bundles, and the electric / optical conversion circuit 111 and the optical / electrical conversion circuit 1 are correspondingly arranged.
The signal is obtained for each bundle, and the signals obtained for each bundle are added and synthesized by a synthesizing circuit to obtain a compressed pulse.

(9) The present invention is applied to a type in which pulse compression is performed by using a transmission waveform that constitutes an inequality cycle and an encoding cycle.

(10) In the case where the shortest of the light guiding thin wires is too short to be constructed easily, the light guiding circuit 112.1.
Similarly, the length of each of the light guide thin wires of 12X is increased by a certain length.

(11) It is said that the conversion characteristics of the electric / optical conversion circuit 111 and the optical / electrical conversion circuit 113 are such that linearity can be obtained even in a low voltage portion.
10AY is configured with no bias level.

(12) In the case of (11) above,
By taking out the received signal 10A or 10AY by capacitor coupling or transformer coupling, for example, a waveform having the amplitude center of the signal waveform at 0V level, for example, a waveform having the amplitude center of the transmission waveform in FIG. 7 at 0V level is provided. A bipolar-type reception signal is created, and this reception signal is given to both of the delay synthesizing units 11 and 11X. / By configuring the light-emitting diode used in the light conversion circuit 111 to have the opposite polarity, the polarity inversion circuit 10X is eliminated.

[0064]

As described above, according to the present invention, since the delay portion in the delay synthesizing unit 11 / 11X is configured by using a large number of outer peripheral reflection type light guide thin wires, for example, optical fibers, the unequalization is performed. Since each delay line corresponding to each step of the cycle or the encoding cycle can be configured to have a very small diameter of several microns, the number of steps is large and the delay amount is several m to several 100 m. Even if there is, each light guide thin wire can be wound and bundled into a small size.

Further, even if the light guide thin wires are closely contacted with each other, interference does not occur between delayed signals, and stable delay synthesis can be performed in terms of secular change. Therefore, a detection device or a communication device with good performance can be provided. It can be provided at low cost by using a commercially available optical fiber, and by providing a single pulse as a drive signal instead of the received signal to the delay synthesizing unit 11. It has the feature that it can be configured as a device that generates a modulated pulse signal by a cycle.

[Brief description of drawings]

 The drawings show examples, and the contents of each drawing are as follows.

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a signal waveform diagram of essential parts of the first embodiment.

FIG. 3 is a block configuration diagram of a main circuit according to the first embodiment.

FIG. 4 is a functional configuration diagram of main parts of the first embodiment.

FIG. 5 is a block configuration diagram of a second embodiment of the present invention.

FIG. 6 is a functional configuration diagram of essential parts of the second embodiment.

FIG. 7 is a principle configuration diagram of a second embodiment.

FIG. 8 is a block diagram of a third embodiment of the present invention.

FIG. 9 is a signal waveform diagram of essential parts of the third embodiment.

FIG. 10 is a principle configuration diagram of a third embodiment.

FIG. 11 is a block diagram of a main part signal waveform and a main part circuit of the related art by the stepwise frequency modulation format.

FIG. 12 is a signal waveform diagram of a main part of a conventional technique in a linear frequency modulation format.

FIG. 13 is a block diagram of a signal waveform of a main part and a circuit of a main part according to a conventional technique by a code modulation format

[Explanation of symbols]

 1 frequency modulation circuit 2 power amplification circuit 3 transmission antenna 4 ground surface 5 underground 6 transmission electromagnetic wave 7A, 7B, 7C underground buried object 8 reflected electromagnetic wave 9 reception antenna 10 reception amplification circuit 11 delay combiner 100 detection device 111 electric / optical Conversion circuit 112 Light guide circuit 113 Optical / electrical conversion circuit

Claims (7)

[Claims] 1. A pulse compressor for obtaining a narrow pulse width signal (hereinafter referred to as a compressed pulse signal) by pulse-compressing a signal having a wide pulse width (hereinafter referred to as a compressed signal) by an inequality cycle or an encoding cycle. The optical signal means for obtaining an optical signal obtained by converting the compressed signal into an electrical signal and an optical signal, and an outer peripheral reflection-type conductor having a length corresponding to the pitch point of each cycle of the compressed signal. Light guiding means for applying to one end of each line of the thin optical wire to obtain an optical signal obtained from each other end as each light guiding signal, and obtaining the compressed pulse signal based on a signal obtained by optically / electrically converting each light guiding signal. A pulse compression device comprising a compression means. 2. The pulse compression apparatus according to claim 1, wherein the optical signal is electrically / optically converted into a first optical signal to obtain a first optical signal, and the first optical signal is compressed. Light guiding means for giving an optical signal obtained from each other end to one end of each wire of the outer peripheral reflection type light guiding thin wire having each length corresponding to the pitch point of each cycle of the signal as each first light guiding signal And the compressed pulse signal (hereinafter, referred to as a first compressed signal) based on a signal obtained by optically / electrically converting each of the first light guide signals.
A inverting means for obtaining a signal obtained by inverting the polarity of the signal to be compressed as an inverting signal; a second optical signal means for obtaining a second optical signal obtained by electrically / optically converting the inverting signal; The two optical signals are applied to one end of each line of the outer peripheral reflection type light guiding thin line having a length corresponding to the pitch point of each cycle of the inverted signal, and the optical signals obtained from the other ends are supplied to the second conductive lines. Light guiding means for obtaining as an optical signal, and the compressed pulse signal (hereinafter referred to as a second compressed signal) based on a signal obtained by optically / electrically converting each of the second light guiding signals.
A pulse compression apparatus comprising: a compression unit that obtains the above-mentioned signal; and an addition and synthesis unit that adds and synthesizes the first compressed signal and the second compressed signal to obtain a synthesized compressed pulse. 3. A reflection type detection apparatus using the pulse compression apparatus according to claim 1 or 2, wherein a signal having a wide pulse width due to an inequality cycle or an encoding cycle is transmitted as a transmission pulse, and the detection object is detected. A reflection type detection device comprising the optical signal means for performing the electrical / optical conversion by using a received signal by a reflected wave obtained from a target as the compressed signal. 4. A pass-through detection device using the pulse compression device according to claim 1 or 2, wherein a signal having a wide pulse width due to an inequality cycle or an encoding cycle is transmitted as a transmission pulse, and is transmitted in a medium. A pass-through detecting device comprising: the optical signal means for performing the electrical / optical conversion by using a received signal by a passing wave that has passed through as the compressed signal. 5. A communication apparatus using the pulse compression apparatus according to claim 1 or 2, wherein a received signal obtained by transmitting an inequality cycle or an encoding cycle as a communication element is used as the compressed signal. A communication device comprising the optical signal means for performing electrical / optical conversion. 6. A modulated pulse signal device for generating a signal having a wide pulse width (hereinafter referred to as a modulated pulse signal) by an inequality cycle or an encoding cycle, using a single pulse signal as a driving signal, wherein the driving is performed. Optical signal means for obtaining an optical signal obtained by electrical / optical conversion of the signal, and the optical signal at one end of each line of the outer peripheral reflection type light guiding thin line having a length corresponding to a pitch point of each cycle of the modulated pulse signal Light guide means for giving an optical signal obtained from each other end as each light guide signal; and modulating means for obtaining the modulated pulse signal based on a signal obtained by optically / electrically converting each light guide signal. A modulated pulse signal generator characterized in that. 7. The device according to claim 3, wherein:
7. An apparatus comprising the modulated pulse signal generator of claim 6.