JP2024012916A - Radio wave transceiver, distributed phased array antenna system, distributed electromagnetic wave observation data collection system, and distributed synthetic aperture radar system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio wave transceiver that can suppress deterioration in beam quality.

SOLUTION: A radio wave transceiver 2 transmits and receives codes to and from another radio wave transceiver 2 via a synchronization antenna 27, and acquires spatiotemporal difference information including both temporal difference information which is a temporal error from a radio wave transceiver 2 serving as a reference and spatial difference information which is a spatial error from the radio wave transceiver 2 serving as the reference using a spatiotemporal difference information acquisition unit 28. Based on the spatiotemporal difference information, a phase shift adjustment unit 24 acts on a phase shifter 221 of a transmitting/receiving module 22 to control an amount of phase shift of a high frequency signal emitted from a communication antenna 21 so as to correct a spatiotemporal error, and suppresses deterioration in beam quality caused by the spatiotemporal error.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention provides a radio wave transmitter/receiver that can acquire spatiotemporal difference information of own aircraft, a distributed phased array antenna system using multiple radio wave transmitters/receivers, and a distributed electromagnetic wave observation data collection system using multiple radio wave transmitters/receivers. and a distributed synthetic aperture radar system using multiple radio wave transmitters and receivers.

BACKGROUND ART Among array antennas in which an array is formed of a plurality of small antennas, there is a phased array antenna in which each antenna element is connected to a phase shifter and beam formation is performed by controlling the amount of relative phase shift between the antennas. Phased array antenna beam control has advantages over conventional mechanically driven scanning beam control, such as improved speed and controllability, and reduced failure rates due to fewer moving parts. Phased array antennas have a wide variety of uses, including adaptively directing the main lobe toward a specific target to improve the efficiency of data transfer, and use as information gathering radar.

In addition, a radar mounted on a flying object such as an artificial satellite or aircraft emits radio waves to the ground while moving, and by receiving and synthesizing the reflected waves, an antenna with a relatively small aperture can effectively achieve a large aperture. There is a synthetic aperture radar (SAR) that can synthesize two antennas. SAR is all-weather and can obtain high-resolution images of topography, etc., regardless of day or night, so it is used for earth observation, planetary exploration, etc. There is also SAR (for example, PALSAR: Phased Array Type L-band Synthetic Aperture Radar) using a phased array.

In the above-described phased array antenna and SAR using the same, relative phase control between antenna elements is important in order to combine radio waves emitted by each antenna element and obtain desired beam characteristics. Therefore, a plurality of antenna elements and phase shifters are generally connected to each other, and the relative phase of radio waves emitted from each antenna element is centrally controlled so as to obtain desired beam characteristics.

In addition, in phased array antennas and SAR that apply them, distributed antenna/distributed SAR technology in which each antenna element making up the array antenna has a reference signal generator and an amplifier, and independently controls its own phase. There is. In such a distributed antenna/distributed SAR, as long as the arrangement of each antenna element is maintained stably, desired beam characteristics can be achieved by adjusting the phase according to the arrangement of each antenna element. However, when the arrangement state of each antenna element changes, it is necessary to perform autonomous control in consideration of the relative phase of radio waves between each antenna element.

For example, when an artificial satellite is launched into satellite orbit with its antenna panel folded and unfolds, the ideal radiation surface shape of a phased array antenna is distorted due to mechanical or thermal distortion. Therefore, ideal characteristics cannot be achieved. A technology has been proposed that uses optical technology to detect phase errors induced by distortions in the antenna shape, calculates the phase correction values necessary to compensate for these errors, and performs real-time shape compensation ( For example, see Patent Document 1). In the phased array antenna described in Patent Document 1, each antenna panel is divided into modules (units consisting of antenna elements, amplifiers, phase shifters, and controllers), so each module itself is miniaturized. By folding them one on top of the other, they can be easily stored inside the payload fairing of a launch vehicle.

In addition, a distributed aperture system has been proposed in which antenna elements are mounted on multiple small satellites, and a phased array antenna is constructed by maintaining the positional relationship between the multiple small satellites in coordination or with the support of a control satellite. (For example, see Patent Document 2). In the distributed aperture system described in Patent Document 2, an electromagnetic coil is used to maintain a distance x and an angle y in order to maintain constant relative positions between small satellites and between a small satellite and a control satellite. A technology has been adopted to change the relative distance between each satellite.

Patent No. 4951622 Patent No. 6506365

However, in the phased array antenna described in Patent Document 1, antenna modules that perform independent phase control are connected by wire and mounted on the same mobile object (satellite), so as the number of modules increases, the overall It becomes large and difficult to store in a narrow space. Moreover, in the phased array antenna described in Patent Document 1, the antenna modules cannot be rearranged arbitrarily, so there is no flexibility to replace a malfunctioning antenna module with a normal antenna module or to operate the antenna module as needed. There is no expandability that allows the number of antenna modules to be increased or decreased or the arrangement structure of antenna modules to be changed accordingly.

On the other hand, in the distributed aperture system described in Patent Document 2, each of a plurality of moving objects (satellites) is equipped with an antenna element, forming an array antenna as a whole. It has excellent scalability, as it has the flexibility to operate by replacing it with a new mobile unit, as well as the ability to increase or decrease the number of mobile units and change the arrangement of mobile units as needed. However, in the distributed aperture system described in Patent Document 2, the individual movable bodies must maintain their mutual positional relationships to form an array, and the positioning accuracy depends on the means of movement of the movable bodies and disturbances. Therefore, deviation from the ideal arrangement due to positioning deviation may become a non-negligible error. That is, if the ideal arrangement of the antenna elements cannot be maintained, the quality of the beam emitted by the array antenna as a whole will deteriorate. Note that this problem is not limited to cases where antenna elements are mounted on a mobile object, but also applies to portable fixed distributed antennas.Due to positional deviation when installing each antenna, the antenna is emitted as a whole. Beam quality deteriorates. In addition, in the distributed aperture system described in Patent Document 2, since independent small satellites are arrayed, highly accurate time synchronization using a common clock cannot be performed as in known phased array antennas. Due to the misalignment, the quality of the beam emitted by the array antenna as a whole is degraded. In addition, even in beamforming antennas that can form receive beams with various directivity by appropriately weighting and combining received signals received by multiple antenna elements, if there is a phase shift in the received signals, the formed beam quality deteriorates. In addition, while moving in the azimuth direction above the image acquisition area, the synthetic aperture radar can generate a two-dimensional image by processing the received signals obtained by multiple antenna elements by repeatedly transmitting and receiving pulses using a synthetic aperture radar signal processing device. Also in radar, if there is a phase shift in the transmitted signal or received signal, the quality of the two-dimensional image will deteriorate.

Therefore, the present invention provides a radio wave transmitter/receiver capable of acquiring phase shift information that can be used as correction information to suppress deterioration of beam quality, a distributed phased array antenna system using a plurality of radio wave transmitters/receivers, and a plurality of radio wave transmitters/receivers. The purpose of this research is to provide a distributed electromagnetic wave observation data collection system using radio waves and a distributed synthetic aperture radar system using multiple radio wave transmitters and receivers.

In order to solve the above problem, the first radio wave transmitter/receiver is a radio wave transmitter/receiver that can be used as an antenna element that configures a phased array antenna system in which a plurality of antenna elements are arranged to obtain desired directivity. The apparatus comprises N communication antennas (N is an arbitrary natural number), a spatio-temporal difference information acquisition section, a phase shift adjustment section, and a reference oscillator that generates a reference frequency signal, and the spatio-temporal difference information acquisition section The unit mutually transmits and receives codes with the other radio wave transmitter/receiver by wireless communication using a synchronization antenna different from the communication antenna, and eliminates the time difference between the reference oscillators and the propagation caused by the code transmission and reception. Based on the delay time, time difference information, which is the time error between the radio wave transmitter/receiver serving as a reference and the own aircraft, and the appropriate position of the own aircraft with respect to the radio wave transmitter/receiver serving as the reference and the current position of the own aircraft. Measures spatial difference information that is a spatial error, acquires spatio-temporal difference information including the temporal difference information and the spatial difference information, and the phase shift adjustment section, based on the spatio-temporal difference information, The method is characterized in that the amount of phase shift of radio waves radiated from the communication antenna is adjusted so as to correct the temporal error and/or the spatial error.

Furthermore, the distributed phased array antenna system according to the present invention is configured using a plurality of first radio wave transmitters/receivers, and has a specific directivity by superimposing the radio waves radiated from the communication antenna of each radio wave transmitter/receiver. The phased array antenna system is characterized by configuring the phased array antenna system.

In addition, in order to solve the above problem, the second radio wave transmitter/receiver arranges a plurality of antenna elements, performs appropriate phase shift processing and appropriate weighting (amplitude amplification) on the received signal received by each antenna element.・A radio wave transmitter/receiver that can be used as each antenna element in a beamforming antenna that can form reception beams with various directivity by performing attenuation processing and combining them, and is capable of transmitting N (N is any natural number) communications. an antenna for communication, a spatio-temporal difference information acquisition section, N signal receiving sections corresponding to each communication antenna, a received data transmitting section, and a reference oscillator that generates a reference frequency signal. The information acquisition unit mutually transmits and receives codes with the other radio wave transmitter/receiver by wireless communication using a synchronization antenna different from the communication antenna, and calculates the time difference between the reference oscillators and the code transmission and reception. Based on the accompanying propagation delay time, temporal difference information that is the time error between the radio wave transmitter and receiver serving as a reference and the own aircraft, and spatial difference information that is the current relative position of the own aircraft with respect to the radio wave transmitter and receiver that serves as a reference. The received data transmitter measures the difference information and acquires the spatio-temporal difference information including the temporal difference information and the spatial difference information, and the received data transmitting unit is configured to measure the received signal received by the signal receiving unit and the received data at the reception timing. The present invention is characterized in that received data in which the spatio-temporal difference information is linked to the unique information of the own machine that is set to enable discrimination between the own machine and the other radio wave transceivers is transmitted to the outside of the machine.

Furthermore, the distributed electromagnetic wave observation data collection system according to the present invention includes a plurality of slave mobilities each having a second radio wave transmitter/receiver mounted on a mobile body, and at least the received data transmitted from the plurality of slave mobilities. a master mobility equipped with a data relay machine mounted on a mobile body, which collects the received data and transfers the collected received data collectively to a predetermined data collection site; Only the master mobility, which is placed in a set electromagnetic wave observation area and has collected the received data from each slave mobility, transfers the collected received data to the data collection center as electromagnetic wave observation data.

In addition, in order to solve the above problem, the third radio wave transmitter/receiver has a plurality of antenna elements arranged, and receives a received signal obtained by repeatedly transmitting and receiving pulses while moving in the azimuth direction above the image acquisition area. , a radio wave transmitter/receiver that can be used as each antenna element in a synthetic aperture radar that can be processed by a synthetic aperture radar signal processing device to generate a two-dimensional image, comprising N communication antennas (N is any natural number); The space-time difference information acquisition unit includes N pulse transmission/reception units corresponding to each communication antenna, a spatio-temporal difference information acquisition unit, a received data transmission unit, and a reference oscillator that generates a reference frequency signal. By wireless communication using a synchronization antenna different from the communication antenna, codes are exchanged with the other radio wave transmitter/receiver, and the time difference between the reference oscillators and the propagation delay time due to the code transmission and reception are determined. Based on this, time difference information, which is the time error between the radio wave transmitter/receiver serving as a reference and the own aircraft, and spatial difference information, which is the current relative position of the own aircraft with respect to the radio wave transmitter/receiver serving as the reference, are measured. and acquires spatio-temporal difference information including the temporal difference information and the spatial difference information, and the reception data transmitting section transmits the reflected signal received by the pulse transmitting/receiving section and the spatio-temporal difference information acquiring section acquiring and transmitting, as received data, the spatio-temporal difference information and unique information of the own aircraft set to enable discrimination between the own aircraft and other radio wave transmitters/receivers to the synthetic aperture radar signal processing device. shall be.

Further, the distributed synthetic aperture radar system according to the present invention includes a master synthetic aperture radar device that includes a third radio wave transmitter/receiver mounted on a moving body and transmits a pulse signal to the image acquisition area and receives a reflected signal; M units (M is an arbitrary natural number) in which the radio wave transmitter/receiver according to claim 5 is mounted on a moving object, and transmit a pulse signal and receive a reflected signal to the same image acquisition area as the master synthetic aperture radar device. a slave synthetic aperture radar device; a synthetic aperture radar signal processing device that processes received data from the master synthetic aperture radar device and the slave synthetic aperture radar device to generate a two-dimensional image; The radar device acquires the spatiotemporal difference information using the master synthetic aperture radar device as the radio wave transmitter/receiver as a reference, and performs phase adjustment to correct the temporal error based on at least the temporal difference information. , transmits a pulse signal synchronized with the pulse transmission of the master synthetic aperture radar device, and the synthetic aperture radar signal processing device transmits a pulse signal in synchronization with the pulse transmission of the master synthetic aperture radar device, and the synthetic aperture radar signal processing device transmits a pulse signal in synchronization with the pulse transmission of the master synthetic aperture radar device, and The method is characterized in that a phase adjustment is performed on the reflected signal to correct the spatial error based on at least the spatial difference information in the spatio-temporal difference information.

According to the first to third radio wave transmitters/receivers according to the present invention, it is possible to acquire spatiotemporal difference information with respect to other radio wave transmitters/receivers. Therefore, a distributed phased array antenna system using a plurality of first radio wave transceivers can suppress deterioration of beam quality by using the spatio-temporal difference information acquired by each radio wave transceiver as correction information. Further, a distributed electromagnetic wave observation data collection system using a plurality of second radio wave transceivers can suppress a decrease in beam quality by using the spatio-temporal difference information acquired by each radio wave transceiver as correction information. Furthermore, the distributed synthetic aperture radar system using a plurality of third radio wave transceivers can suppress deterioration in the quality of two-dimensional images by using the spatio-temporal difference information acquired by each radio wave transceiver as correction information.

(A) is a schematic configuration diagram of a distributed phased array antenna system according to the present embodiment. (B) is a schematic configuration diagram of a radio wave transmitter/receiver of a first configuration example used in a distributed phased array antenna system. (A) is an image diagram showing a first example of radiation characteristics in a distributed phased array antenna system in which radio wave transmitters and receivers are arranged at equal intervals in a straight line so as to function as a linear array antenna. (B) is an image diagram showing a second example of radiation characteristics in a distributed phased array antenna system in which radio wave transmitters and receivers are arranged at equal intervals in a straight line so as to function as a linear array antenna. (A) is an image diagram showing radiation characteristics when there is no time error in the reference oscillator of each radio wave transmitter/receiver used in the distributed phased array antenna system. (B) is an image diagram showing radiation characteristics when there is a time error in the reference oscillator of each radio wave transmitter/receiver used in the distributed phased array antenna system. (C) is an image diagram showing radiation characteristics when the time error included in the reference oscillator of each radio wave transmitter/receiver used in the distributed phased array antenna system is corrected based on time difference information. FIG. 3 is an explanatory diagram of a correction operation performed by each radio wave transmitter/receiver used in the distributed phased array antenna system to detect mutual phase differences and achieve phase synchronization. It is a schematic block diagram of the radio wave transceiver of a 2nd example of a structure. It is a 1st schematic block diagram of the radio wave transceiver of a 3rd example of a structure. (A) is an image diagram of a distributed phased array antenna system using radio wave transmitters and receivers mounted on multiple vehicles. (B) is an image diagram of a distributed phased array antenna system using radio wave transmitters and receivers mounted on a plurality of unmanned aircraft. FIG. 1 is a schematic configuration diagram of a distributed electromagnetic wave observation data collection system composed of a plurality of slave mobility devices and one master mobility device. (A) is a schematic configuration diagram of a radio wave transmitter/receiver used for slave mobility. (B) is a schematic configuration diagram of a radio wave transmitter/receiver used for master mobility. FIG. 1 is a schematic configuration diagram of a distributed synthetic aperture radar system including one master synthetic aperture radar device, a plurality of slave synthetic aperture radar devices, and one mobile control device. One master synthetic aperture radar device and M slave synthetic aperture radar devices transmit pulse signals to the observation target, and one master synthetic aperture radar device and M slave synthetic aperture radar devices receive reflected signals. 1 is a schematic configuration diagram of a distributed synthetic aperture radar system. Outline of a distributed synthetic aperture radar system in which a pulse signal is transmitted from one master synthetic aperture radar device to an observation target, and reflected signals are received by one master synthetic aperture radar device and M slave synthetic aperture radar devices. FIG.

Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. What is shown in FIG. 1(A) is a distributed phased array antenna system 1, in which four radio wave transceivers 2 (for example, a first radio wave transceiver 2A, a second radio wave transceiver 2A, a second radio wave transceiver 2A, a 2B, a third radio wave transmitter/receiver 2C, a fourth radio wave transmitter/receiver 2D), and a system control device 11. It should be noted that the first to fourth radio wave transmitters/receivers 2A to 2D distributed at appropriate locations all have a common function (for example, see FIG. 1(B)), and the first to fourth radio wave transmitters/receivers 2A to 2D are distributed at appropriate locations. If there is no need to distinguish between 2A and 2D, they are simply referred to as radio wave transmitter/receiver 2. Furthermore, the number of radio wave transceivers 2 that constitute the distributed phased array antenna system 1 is not limited to four, but may be two or three, or five or more.

The radio wave transmitter/receiver 2 can be used as an antenna element constituting a "phased array antenna system in which a plurality of antenna elements are arranged to obtain desired directivity." That is, in the distributed phased array antenna system 1, a plurality of radio wave transmitters/receivers 2 are arranged, all or some of the antennas of these radio wave transmitters/receivers 2 are excited by instructions from the system control device 11, and the excitation amplitude and excitation are adjusted. The desired directivity is obtained by superimposing the radio waves obtained by controlling the phase.

Note that array antennas are classified into linear arrays, planar arrays, circular arrays, conformal arrays, etc. depending on the arrangement method. Further, an array antenna in which the beam direction and radiation pattern are controlled by the relative phase of each radiating element is particularly referred to as a phased array antenna. Furthermore, an antenna in which the radiating elements are separated without being electrically connected and each radiating element controls itself independently is called a distributed array antenna. Based on these existing technologies, the present invention, which is a system that controls the beam direction and radiation pattern by the relative phase of the radio wave transmitter/receiver 2, which is an independent radiating element, is referred to as a distributed phased array antenna system 1.

In addition, in order for the distributed phased array antenna system 1 to function as a phased array antenna, the system control device 11 must instruct the first to fourth radio wave transceivers 2A to 2D to control directivity, and It is necessary to transmit received signals from the four radio wave transceivers 2A to 2D to the system control device 11. Therefore, the system control device 11 and the first to fourth radio wave transceivers 2A to 2D require a bidirectional signal transmission function. Although an example has been shown in which the radio wave transmitters and receivers 2A to 2D are connected by wire, wireless connections may also be used. Furthermore, if the function of the system control device 11 is added to any one of the first to fourth radio wave transceivers 2A to 2D constituting the distributed phased array antenna system 1, the system control device 11 can be prepared separately. There's no need.

Each radio wave transmitter/receiver 2 is housed in an independent housing and can be handled individually, so if the size and weight of the radio wave transmitter/receiver 2 are sufficiently reduced, it becomes highly portable. Moreover, since the radiation characteristics can be controlled by arbitrarily changing the number, arrangement, etc. of the radio wave transmitters/receivers 2 used in the distributed phased array antenna system 1, the degree of freedom as a system can be increased. However, a negative factor of dispersing the radiation elements is that it is difficult to achieve highly accurate positioning of the radio wave transmitter/receiver 2 in an ideal arrangement, which may lead to errors. In addition, since each radio wave transmitter/receiver 2 is independent, it is necessary to generate a reference clock etc. for each radio wave transmitter/receiver 2, and high precision synchronization using a common clock cannot be performed as in known phased array antennas. Therefore, it becomes an error factor. Therefore, the radio wave transmitter/receiver 2 of this embodiment is provided with a function that can correct temporal errors and spatial errors, so that deterioration of the beam quality obtained by the distributed phased array antenna system 1 can be suppressed.

Hereinafter, with reference to FIG. 1(B), the error correction function of the radio wave transmitter/receiver 2 shown as a first configuration example will be described in detail. Note that the signal communication function and processing operations performed by the radio wave transmitter/receiver 2 with the system control device 11 are omitted in FIG. 1(B) because various techniques employed in known phased array antennas can be applied. did.

The radio wave transmitter/receiver 2 includes a communication antenna 21, a transmitter/receiver module 22, a radiation controller 23, a phase adjuster 24, a transmitter/receiver controller 25, a reference oscillator 26, a synchronization antenna 27, and a spatiotemporal difference information acquisition unit 28. Ru. Note that the communication antenna 21 is preferably a dipole antenna, a slot antenna, a microstrip antenna, or the like. The communication antenna 21, the transmission/reception module 22, the radiation control section 23, and the phase adjustment section 24 function as one radiating element constituting a phased array. The radiation control section 23 controls the frequency and intensity of the high frequency wave that is fed to the antenna, and the phase adjustment section 24 controls the phase of the high frequency wave. The transmitting/receiving module 22 includes a phase shifter 221 and an amplifier circuit (for example, a transmitting amplifier 222 and a receiving low-noise amplifier 223) that can arbitrarily adjust the phase of each of the transmitting path and the receiving path. The controller 221 switches between transmitting the high-frequency waves fed through the communication antenna 221 to the communication antenna 21, or demodulating the high-frequency waves received by the communication antenna 21 after phase-shifting them. That is, the radio wave transmitter/receiver 2 can radiate and receive radio waves whose phase is arbitrarily controlled from the communication antenna 21. Note that in the following explanation regarding the radio wave transmitter/receiver 2, an example of the operation of emitting radio waves will be described, but the same effect can be obtained even when receiving radio waves.

FIG. 2(A) shows a distributed phased array antenna system 1 having a linear array configuration in which first to fourth radio wave transceivers 2A to 2D are arranged in a straight line at a distance d from each other. Furthermore, the clocks of the first to fourth radio wave transmitters/receivers 2A to 2D are synchronized with ideal precision. Therefore, when high frequencies synchronized with the excitation phase Φ are transmitted from each transmitting antenna 21 of the first to fourth radio wave receivers 2A to 2D, the waves are perpendicular to the arrangement direction of the first to fourth radio wave transceivers 2A to 2D. A wavefront WF of a composite wave whose direction is the directional direction is generated. On the other hand, in FIG. 2(B), a high frequency wave with an excitation phase Φ is transmitted from the transmitting antenna 21 of the first radio wave transceiver 2A, a high frequency wave with an excitation phase Φ+Δφ is transmitted from the transmitting antenna 21 of the second radio wave transceiver 2B, and a third radio wave is A case is shown in which a high frequency wave with an excitation phase of Φ+2Δφ is transmitted from the transmitting antenna 21 of the transmitter/receiver 2C, and a high frequency wave with an excitation phase of Φ+3Δφ is transmitted from the transmitting antenna 21 of the fourth radio wave transmitter/receiver 2D. In this way, when transmitting a high frequency wave whose phase is adjusted according to the array position of the first to fourth radio wave transmitters/receivers 2A to 2D, a composite wave whose directional direction is tilted at an angle θ with respect to the directional direction of FIG. 2(A) is generated. A wavefront WF is generated.

However, each radio wave transmitter/receiver 2 used in the distributed phased array antenna system 1 is not centrally managed unlike known array antennas and operates independently from other radio wave transmitters/receivers 2. The state of high-frequency signals such as excitation amplitude and phase must be individually understood and controlled. The challenge at this time is to align the phases with other radio wave transmitters/receivers 2 according to a certain rule. To do this, we need time difference information, which is the time error between the reference radio wave transmitter/receiver 2 and the own aircraft, and spatial error between the appropriate position of the own aircraft with respect to the reference radio wave transmitter/receiver 2 and the own aircraft's current position. It is important to understand the spatial difference information and control the high frequency state so as to correct the amount of phase shift required to obtain the desired composite wave. Note that the time difference information may be an error between the reference oscillator 26 of the radio wave transmitter/receiver 2 serving as a reference and the reference oscillator 26 of the own device, or the reference frequency generated by the reference oscillator 26 of the radio wave transmitter/receiver 2 serving as the reference. It may be an error between the clock that is counting the signal (for example, the reference clock signal) and the clock of the own device. In addition, the spatial difference information indicates the spatial error between the ideal position assigned to the aircraft in the distributed phased array antenna system 1 (appropriate position) and the current position of the aircraft, which serves as a reference for radio wave transmission and reception. This is acquired based on the position of aircraft 2 (hereinafter referred to as the reference aircraft). Even if the position of the reference device is slightly deviated from the proper position, if the other radio wave transmitter/receiver 2 is placed at the correct position relative to the reference device, the distributed phased array antenna system 1 will work as intended. This is because it is possible to achieve the directivity of

Therefore, in addition to the reference oscillator 26, the radio wave transmitter/receiver 2 is provided with a synchronization antenna 27 and a spatio-temporal difference information acquisition section 28. The spatio-temporal difference information acquisition unit 28 provides spatio-temporal difference information including both temporal difference information with other radio wave transceivers 2 and spatial difference information with other radio wave transceivers 2. get. Based on this spatio-temporal difference information, the phase adjustment section 24 acts on the phase shifter 221 of the transmitting/receiving module 22 to control the amount of phase shift of the high frequency signal emitted from the communication antenna 21. In this way, by grasping the spatio-temporal difference information including the above-mentioned temporal difference information and spatial difference information and correcting the temporal error and spatial error, it is possible to control multiple radio wave transmitters and receivers 2 that operate independently. Even if the two components are used together, the desired composite wave can be obtained in cooperation. For example, the spatio-temporal difference information acquisition unit 28 transmits and receives codes to and from another radio wave transmitter/receiver 2 by wireless communication via the synchronization antenna 27, and calculates the time difference between the mutual reference oscillators 26 and the propagation delay time due to code transmission and reception. Based on this, the temporal difference information and the spatial difference information are measured. Note that the phase shift may be measured by communicating with another radio wave transmitter/receiver 2 connected by wire without using the synchronization antenna 27.

The spatio-temporal difference information including the temporal difference information and the spatial difference information acquired by the spatio-temporal difference information acquisition section 28 is supplied to the phase adjustment section 24 via the transmission/reception control section 25, and is used for control to correct phase shift. be done. That is, the radiation control unit 23 excites the high-frequency signal based on the clock source provided by the reference oscillator 26, and the phase adjustment unit 24 controls the phase amount by the phase shifter 221 based on the spatio-temporal difference information to adjust the spatio-temporal signal of the high-frequency signal. The communication antenna 21 transmits a high-frequency signal in which the optical error is corrected and deterioration in beam quality is suppressed. This makes it possible to obtain a desired composite wave as a distributed phased array antenna system 1 using a plurality of radio wave transmitters/receivers 2 that operate independently. Such a phase correction operation will be explained with reference to FIG. 3. In FIG. 3, in order to simplify the explanation, a linear array structure is used in which the first to third radio wave transceivers 2A to 2C are arranged in a line at equal intervals.

For example, as shown in FIG. 3(A), if the reference oscillators 26 of the first to third radio wave transceivers 2A to 2C are synchronized with high precision and there is no time error in the time TM, the transmitting and receiving module There is no time error in the high frequency signal supplied to 22. First, if the phase shift amount Φa0 for phase adjustment in the transmitting/receiving module 22 of the first radio wave transmitting/receiving device 2A is set to 0 (zero) as instructed by the system control device 11, the high frequency signal emitted from the communication antenna 21 is The phase will be as instructed. Similarly, if the phase shift amount Φb0 for phase adjustment in the transmitting/receiving module 22 of the second radio wave transmitting/receiving device 2B is set to π/6 as instructed by the system control device 11, the high frequency signal emitted from the communication antenna 21 is The phase will be as instructed. Similarly, if the phase shift amount Φc0 for phase adjustment in the transmitting/receiving module 22 of the third radio wave transmitting/receiving device 2C is set to π/3 (=2π/6) as instructed by the system control device 11, the communication antenna 21 The emitted high-frequency signal has a phase as instructed. In this way, if there is no time error in the time TM of the first to third radio wave transceivers 2A to 2C, the wavefronts are aligned in the pointing direction according to the phase difference of the high frequency signals emitted from each communication antenna 21, A suitable directivity can be obtained.

However, as shown in FIG. 3(B), if the times of the first to third radio wave transceivers 2A to 2C are not synchronized with the master clock, a time error may occur in the high frequency signal supplied to the transceiver module 22. It will happen. First, since the clock of the first radio wave transmitter/receiver 2A is synchronized with the master clock (coinciding with the time TM), the high frequency signal whose phase has been adjusted (phase shift amount Φa0 = 0) within the transmitter/receiver module 22 is as instructed. It becomes the phase. However, since the clock of the second radio wave transmitter/receiver 2B is ahead of the master clock by Δtb, time TM + Δtb becomes the oscillation reference for the high frequency signal, and the high frequency signal whose phase is adjusted (phase shift amount Φb0 = π/6) within the transmitting/receiving module 22 The signal will be out of phase with respect to the original indication. Also, since the clock of the third radio wave transmitter/receiver 2C is ahead of the master clock by Δtc, the time TM+Δtc becomes the oscillation reference for the high frequency signal, and the high frequency signal is phase-adjusted (phase shift amount Φc0 = π/3) within the transmitter/receiver module 22. The signal will be out of phase with respect to the original indication. Therefore, the wavefronts of the high-frequency signals emitted from each communication antenna 21 in FIG. 3(B) are not aligned in the directivity direction according to the phase difference, and suitable directivity cannot be obtained.

On the other hand, as shown in FIG. 3(C), even if the times of the first to third radio wave transmitters 2A to 2C are not synchronized with the master clock, the phase adjustment unit 24 adjusts the phase amount so that the time difference is corrected. By adjusting the above, it is possible to eliminate the temporal error that occurs in the high frequency signal. In addition, below, the period of the high frequency signal to be transmitted is assumed to be P. First, since the clock of the first radio wave transmitter/receiver 2A is synchronized with the master clock (coinciding with the time TM), the corrected phase adjustment amount ΦaC that the phase adjustment section 24 instructs the transmitting/receiving module 22 remains Φa0 (=0). The high frequency signal emitted from the communication antenna 21 has a phase as instructed. However, since the clock of the second radio wave transmitter/receiver 2B is ahead of the master clock by Δtb, the corrected phase adjustment amount ΦbC = Φb0 - 2πΔtb/P (=π/ 6−2πΔtb/P) by the phase adjustment unit 24 to the transmitting/receiving module 22, so that the high frequency signal emitted from the communication antenna 21 has the phase as instructed. Also, since the clock of the third radio wave transmitter/receiver 2C is ahead of the master clock by Δtc, the corrected phase adjustment amount ΦcC = Φc0 - 2πΔtc/P (=π/ 3-2πΔtc/P) by the phase adjustment unit 24 to the transmitting/receiving module 22, so that the high frequency signal emitted from the communication antenna 21 has the phase as instructed. In this way, even if there is a time error in the time TM of the first to third radio wave transceivers 2A to 2C, if the phase amount is adjusted to correct the time difference, each communication antenna 21 can emit light. The wavefront is aligned in the directivity direction according to the phase difference of the high-frequency signal, and suitable directivity can be obtained.

As mentioned above, if the spatio-temporal difference information is acquired between the independently operating radio wave transmitter/receiver 2 and the amount of phase shift of the high frequency signal is corrected, unintended phase shift of each wave source forming the composite wave can be avoided. The beam quality of the distributed phased array antenna system 1 can be improved. Note that although FIG. 3 shows only the method for correcting temporal errors, the method for correcting spatial errors is also similar. By acquiring spatio-temporal difference information between the radio wave transmitter and receiver 2 and correcting the amount of phase shift of the high frequency signal, it is possible to reduce unintended phase shifts of each wave source forming the composite wave. Of course, if both temporal and spatial errors occur, if the phase of the high-frequency signal is corrected by taking both the temporal and spatial errors into account, each wave source that forms the composite wave can be corrected. It is possible to reduce unintended phase shifts.

Note that the method for acquiring temporal difference information and the method for acquiring spatial difference information by the spatiotemporal difference information acquisition unit 28 is not particularly limited, and any known and existing appropriate method may be used. For example, when using GNSS (Global Navigation Satellite System), each radio wave transmitter/receiver 2 may perform a correction operation to synchronize with the GNSS satellite as a master clock. The method of synchronizing time using GNSS is effective on the ground and in the air where GNSS signals can reach. Furthermore, various time synchronization methods such as IEEE802.1AS-2011 using propagation delay time between each radio wave transmitter/receiver 2 may be used. In this case, one of the plurality of radio wave transceivers 2 configuring the distributed phased array antenna system 1 may function as a master clock, or the relative time difference with the radio wave transceiver 2 serving as a reference clock may be adjusted. Make it discoverable. For example, as shown in FIG. 4, it is assumed that the first radio wave transceiver 2A is equipped with a master clock, and the second radio wave transceiver 2B uses its own internal clock with an error φAB based on the propagation delay time with the first radio wave transceiver 2A. Correct. Similarly, the third radio wave transceiver 2C corrects its internal clock using an error φAC based on the propagation delay time with the first radio wave transceiver 2A. The third radio wave transmitter/receiver 2C may correct its internal clock using the error φBC based on the propagation delay time with the second radio wave transmitter/receiver 2B after clock correction, or may correct its own clock using the average of the error φAC and the error φBC. It is also possible to correct the own device's clock using a value or the like. The fourth radio wave transceiver 2D has an error φBD based on the propagation delay time with the second radio wave transceiver 2B after clock correction or an error φCD based on the propagation delay time with the third radio wave transceiver 2C after clock correction. The clock of the device may be corrected, or the clock of the own device may be corrected using the average value of the error φBD and the error φCD. This method using propagation delay time (RTT) can obtain high synchronization accuracy and is therefore desirable from the viewpoint of improving beam quality.

Further, instead of correcting the temporal phase shift, adjustment may be made to cancel the phase shift of the reference oscillator 26 (ie, synchronize it) so as to cancel out the detected phase shift. For example, the radio wave transmitter/receiver 2' shown in FIG. A difference information detector 282 is provided. The temporal difference information detector 282 receives information indicating the master clock or its phase from the synchronization antenna 27, and adjusts the excitation phase of the reference oscillator 26' to the master clock based on the received information. More specifically, a radio wave of a specific frequency transmitted from the master clock is received by the synchronization antenna 27, and a phase difference between the radio wave and the clock of the reference oscillator 26' is detected by the temporal difference information detector 282. . By feeding back the temporal error obtained by the temporal difference information detector 282 to the reference oscillator 26', the reference oscillator 26' can be excited in the same phase as the master clock. In this way, by synchronizing the oscillation clock of the reference oscillator 26' with the master clock at the phase level, phase shift can be minimized and beam quality can be improved. Further, the master clock does not have to be global, and may be local synchronization that is established only between the plurality of radio wave transceivers 2 that constitute the distributed phased array antenna system 1. In this case, the radio wave transceiver 2 serving as the master clock may be arbitrarily selected from among the plurality of radio wave transceivers 2 configuring the distributed phased array antenna system 1.

on the other hand. Spatial difference information, that is, the positional relationship between multiple radio wave transceivers 2, can be obtained using wireless methods such as distance estimation using GNSS, AoA (Angle of Arrival), AoD (Angle of Departure), and RSSI (Received Signal Strength Indicator). It can be detected using positioning technology. In particular, GNSS is an effective means when the radio wave transmitter/receiver 2 is placed in a place where GNSS signals can reach, such as on the ground or in the air. In addition, when acquiring spatial difference information, the relative positional relationship is grasped only between the multiple radio wave transmitters and receivers 2 that constitute the distributed phased array antenna system 1, rather than the global position such as latitude, longitude, and altitude. It doesn't matter if it's something local that can be done. Therefore, a positioning technique that allows a plurality of radio wave transceivers 2 to determine each other's positions using AoA, AoD, RSSI, or the like may be used. Furthermore, the positional relationship may be grasped by measuring the mutual distance using the propagation delay time of radio waves. At this time, it is only necessary to know the distance between the plurality of radio wave transmitters/receivers 2.

The spatial difference information obtained in this way becomes the material for determining the amount of phase shift determined by the transmission/reception control section 25. For example, ideally, if the device deviates from the arrangement of the array antenna, the phase shift due to the spatial error is determined and the amount of phase shift is adjusted so that the influence on beam quality is minimized. This amount of phase shift is calculated using methods such as Maxwell's equations, Fresnel-Kirchhoff diffraction theory, and ray tracing, and it is desirable to use a value that will result in an optimal beam as a whole. More simply, the phase shift may be calculated from the distance representing the shift from the ideal position and the propagation wavelength of the radio wave, and the phase of the high-frequency signal may be adjusted to correct this spatial error.

Furthermore, the radiation element function installed in the radio wave transmitter/receiver 2 is not limited to one, but includes N communication antennas 21 (N is an arbitrary natural number) and a transmitting/receiving module 22 corresponding to each transmitting antenna 21. may be provided. The radio wave transmitter/receiver 2'' shown in FIG. 6 is equipped with two sets (N=2) of radiating element functions, including a first communication antenna 21A, a second communication antenna 21B, first and second transmission antennas 21A, A first transmitting/receiving module 22A and a second transmitting/receiving module 22B respectively corresponding to the communication antenna 21B are provided.The high frequency signal radiated from the first communication antenna 21A and the high frequency signal radiated from the second communication antenna 21B are independently controlled. Therefore, a first radiation control section 23A and a first phase adjustment section 24A corresponding to the first transmission/reception module 22A are provided, and a second radiation control section 23B and a second phase adjustment section 24B corresponding to the second transmission/reception module 22B are provided. In this way, in the radio wave transmitter/receiver 2'' provided with a plurality of radiating element functions, the radiating element functions can be arranged with narrower intervals. For example, if the element spacing is d, the signal wavelength is λ, and the maximum scanning angle is θ, then d/λ=1/(1+sinθ), so adjust the element spacing d so that d≦λ/(1+sinθ). By doing so, the generation of grating lobes can be suppressed.

As described above, the radio wave transmitter/receiver 2, which can acquire temporal difference information and spatial difference information and adjust the phase of a high-frequency signal to correct the amount of spatiotemporal error, independently controls the radiating elements of the array antenna. Not only can it be used as a mobile device, but it can also be mounted on a mobile vehicle to create a mobile distributed phased array antenna system. For example, the mobile body equipped with the radio wave transmitter/receiver 2 may be a vehicle 3 running on the ground (see FIG. 7(A)), a ship sailing on the sea, an aircraft or a UAV (Unmanned Aerial Vehicle) flying in the airspace. 4 (see Figure 7(B)), artificial satellites in orbit, etc. Note that the mobile body and the radio wave transmitter/receiver 2 may not be separate bodies, but may have an integrated structure.

The mobile distributed phased array antenna system 1' shown in FIG. 7A includes first to eighth radio wave transceivers 2A to 2H mounted on first to eighth vehicles 3A to 3H, respectively. , the first radio wave transmitter/receiver 2A has the function of the system control device 11. In this distributed phased array antenna system 1', unlike the aforementioned distributed phased array antenna system 1, each radio wave transmitter/receiver 2 is not fixedly arranged. , the relative positions of the first to eighth radio wave transmitters/receivers 2A to 2H change from moment to moment. However, since each radio wave transmitter/receiver 2 is provided with a spatio-temporal difference information acquisition unit 28, it is possible to acquire temporal difference information and spatial difference information and emit a high-frequency signal with the spatio-temporal error amount corrected. It is also possible to follow changes in the spatio-temporal error amount accompanying the movement of the first to eighth vehicles 3A to 3H. Therefore, even in the mobile distributed phased array antenna system 1' using the vehicle 3, which is a moving body, it is possible to form a composite wave with the main lobe directed in a specific direction.

Note that if the first to eighth vehicles 3A to 3H are self-driving cars, etc., the first to eighth vehicles 3A to 3H are arranged so that the first to eighth radio wave transmitters 2A to 2H are ideally arranged as array antennas. Since the antennas 3A to 3H can move in formation, they can move while maintaining the beam quality in the distributed phased array antenna system 1'. Furthermore, since the first to eighth radio wave transmitters/receivers 2A to 2H can grasp each other's positions from the spatio-temporal difference information acquired by the spatio-temporal difference information acquisition unit 28, each radio wave transmitter/receiver 2 can determine the position of its own device. If you move it, you can judge whether it will be the ideal arrangement as an array antenna. Therefore, by providing a movement correction instruction means in each radio wave transmitter/receiver 2 and transmitting movement correction information from the movement correction instruction means to the movement control device of each moving object (for example, the automatic driving control device of the vehicle 3), each movement If the body movement control device corrects the movement direction and movement speed based on the movement correction information, each mobile body can move each radio wave transmitter/receiver 2 to an optimal position. Note that even if the optimal placement of each radio wave transmitter/receiver 2 cannot be achieved only by correcting the movement of each moving object, each radio wave transmitter/receiver 2 can correct the phase of the high-frequency signal based on the spatio-temporal difference information detected at that time. Therefore, as a distributed phased array antenna system 1', deterioration in beam quality can be suppressed to a minimum. Of course, even in cases where the movement of a moving object cannot be corrected appropriately (for example, when a person is driving a vehicle), it is possible to suppress the quality degradation of the composite wave by correcting the phase of the high-frequency signal by each radio wave transmitter/receiver 2. There is sex.

The mobile distributed phased array antenna system 1″ shown in FIG. 7(B) is such that the first to ninth UAVs 4A to 4I are equipped with the first to ninth radio wave transceivers 2A to 2I, respectively. 1 radio wave transmitter/receiver 2A has the function of the system control device 11. In this distributed phased array antenna system 1'', each radio wave transmitter/receiver 2 is mounted on a UAV 4, which is a flying mobile object, so that the space can be It is possible to realize a three-dimensional array arrangement. For example, the function of an array antenna with a three-dimensional curved surface, which is difficult to achieve with a large aperture, can be easily realized by the distributed phased array antenna system 1''. If it is not variable, by finely adjusting the three-dimensional arrangement of each radio wave transmitter/receiver 2 in order to suppress individual variations, deterioration in beam quality can be suppressed.

In addition, if the UAV 4 is an autonomous flight type, each radio wave transmitter/receiver 2 is provided with a movement correction instruction means, and the movement correction instruction means is sent to a movement control device of each moving object (for example, an autonomous flight rotation control device of the UAV 4) for movement correction. By transmitting the information, if the movement control device of each moving object corrects the moving direction and moving speed based on the movement correction information, each moving object can move each radio wave transmitter/receiver 2 to an optimal position. . Note that if each UAV 4 is an unmanned aircraft that can be remotely controlled wirelessly, each radio wave transmitter/receiver 2 is provided with a movement control unit that controls the movement of the mobile object, and the movement control unit of each radio wave transmitter/receiver 2 is controlled by each UAV 4. may be directly controlled. In this case, in addition to controlling the relative movement of each radio wave transmitter/receiver 2 constituting the distributed phased array antenna system 1″, the movement control unit controls the spatio-temporal difference information acquired by the spatio-temporal difference information acquisition unit 28. Movement control is also performed to correct the phase shift based on the radio wave transmitter/receiver 2.The movement control unit of each radio wave transmitter/receiver 2 controls the movement of each UAV 4, and until each radio wave transmitter/receiver 2 moves to the ideal position, each radio wave transmitter/receiver By correcting the phase of the high frequency signal by the device 2, deterioration in beam quality can be suppressed.

Furthermore, in the distributed phased array antenna system 1'', by taking advantage of the fact that each UAV 4 can form a free formation, each radio wave transmitter/receiver 2 can be arranged to form an unevenly spaced array as a whole. If this arrangement is adopted, it is possible to arrange the elements with a wider spacing than under normal grating lobe generation conditions, so it is possible to reduce the number of elements (the number of radio wave transceivers 2 to be used). Since the amplitude distribution can be equivalently determined by the arrangement density, low side lobes can be achieved even when the amplitude distribution of each radio wave transmitter/receiver 2 is constant, and the directivity can be further improved as a distributed phased array antenna system 1''.

As mentioned above, when the radio wave transmitter/receiver 2 is mounted on a mobile object such as a vehicle 3 or a UAV 4, the distributed phased array antenna system 1', 1'' as a whole becomes equipped with a means of transportation, which is highly convenient. Furthermore, depending on the intended use of the distributed phased array antenna system 1', 1'', the arrangement of each radio wave transmitter/receiver 2 can be changed by moving the mobile object, providing a high degree of freedom. In addition, if a mobile body is equipped with a radio wave transmitter/receiver 2 and a mobile function is added, scalability that can flexibly respond to scale changes of the distributed phased array antenna system 1', 1'' can be realized, and the advantages of a distributed system can be realized. Make the most of it.

For example, each radio wave transmitter/receiver 2 is provided with a self-diagnosis section that can diagnose failures that have occurred in itself, and an autonomous movement control section that can arbitrarily control the movement of the mobile body on which it is mounted. When the radio wave transmitter/receiver 2 that constitutes the distributed phased array antenna system 1', 1'' is judged to have failed by the self-diagnosis section, it is autonomously moved by the autonomous movement control section and removed from the array arrangement. If the other radio wave transmitters/receivers 2 autonomously adjust their arrangement so as to fill in the gaps, the effects of failures that occur in some of the radio wave transmitters/receivers 2 will be minimized, and the distributed phased array antenna system 1', 1'' will continue to operate. can operate as In addition, if there is a radio wave transmitter/receiver 2 on standby as a standby unit, the standby unit will autonomously move to the appropriate position in place of the radio wave transmitter/receiver 2 that has fallen due to a failure, thereby quickly ensuring proper array arrangement. It may be possible to restore the . In addition, if the self-diagnosis section of the radio wave transmitter/receiver 2 diagnoses that it is unable to emit radio waves of the original output, but it is possible to emit weak radio waves, the radio waves with weak radiation ability will be sent to the outermost part of the array arrangement. By rearranging the transceiver 2, the effects of failure can be reduced. Furthermore, the radio wave transceivers 2 may be arranged to form an optimal unequal spacing array, taking into consideration variations in the radiation characteristics of the radio wave transceivers 2. Furthermore, if the autonomous movement control unit of each radio wave transmitter/receiver 2 has a self-learning function using reinforcement learning, an optimal solution that can obtain the desired composite wave as a distributed phased array antenna system 1', 1'' can be found. This self-learning function enables autonomous control in which the autonomous movement control section of each radio wave transmitter/receiver 2 autonomously rearranges the arrangement by taking into consideration the radiation characteristics of each radio wave transmitter/receiver 2. If each radio wave transmitter/receiver 2 has a can be minimized.

The above-described distributed phased array antenna system 1, 1', 1'' uses radio wave transceivers 2, 2', 2'', etc. that can acquire spatiotemporal difference information to suppress deterioration in the quality of the transmitted beam. However, radio wave transmitters and receivers that can acquire spatio-temporal difference information can receive signals with various directivity by performing appropriate phase shift processing and appropriate weighting (amplification/attenuation in the amplitude direction) on the received signals. It can also be applied to beamforming, which can form beams. What is shown in FIG. 8 is a distributed electromagnetic wave observation data collection system 5 that uses beamforming technology to collect data for observing incoming electromagnetic waves. This distributed electromagnetic wave observation data collection system 5 can be used not only for radio wave observation alone, but also as distributed antennas (for example, radio telescopes) for observation using very long baseline interferometry (VLBI). .

This distributed electromagnetic wave observation data collection system 5 includes, for example, one master mobility unit 51M and the first to eighth slave mobility units 51S1 to 51S8 (if there is no particular need to distinguish between them, (simply referred to as slave mobility 51S). The first to eighth slave mobilities 51S1 to 51S8 and the master mobility 51M each receive radio waves arriving at the radio wave observation area OA, and the first to eighth slave mobilities 51S1 to 51S8 transmit received data (observation data) to the master mobility 51M. Send to. Then, the master mobility 51M that has collected the observation data moves to a low altitude at predetermined data transfer timings (for example, at regular intervals or when the observation data storage capacity reaches a predetermined value) and observes from a relatively short distance. Observation data is transmitted to the observation data collection station CP, which serves as a data collection station. In this way, if the master mobility 51M moves to a low altitude and transmits observation data, it can transmit large-capacity communication with lower transmission power than when transmitting directly from the sky to the observation data collection station CP. be able to.

The observation data collection station CP that has received the observation data performs appropriate phase shift processing and appropriate weighting processing on the received signals of the observation data collected by the master mobility 51M and the first to eighth slave mobilities 51S1 to 51S8 and synthesizes them. By doing so, a receiving beam can be generated. At this time, by changing the phase shift processing and weight combinations for each received signal, different patterns of reception beams can be generated. That is, outputs of various beam patterns can be obtained from observation data of electromagnetic waves received in a predetermined arrangement by the master mobility 51M and the first to eighth slave mobilities 51S1 to 51S8.

Note that the method of transferring the observation data collected by the master mobility 51M to the observation data collection center is not particularly limited; for example, a data collection vehicle CV that receives observation data is kept on standby within the electromagnetic wave observation area OA, It is also possible to transmit the information directly from the master mobility 51M to the data collection vehicle CV. Alternatively, the observation data of the Master Mobility 51M may be accumulated on a recording medium, and at the data transfer timing, an investigator or the like may remove the recording medium on which the observation data has been accumulated from the Master Mobility 51M that has descended to the ground, and make sure there is sufficient free space. It may also be possible to replace the recording medium with one with a larger capacity and quickly return the master mobility 51M to its normal position in the sky. Alternatively, the master mobility 51M and the first to eighth slave mobilities 51S1 to 51S8 move to the electromagnetic wave observation area OA, perform electromagnetic wave observation on the ground, and at a predetermined data transfer timing, only the master mobility 51M moves to the observation data collection station. It is also possible to move to a CP or the like and transfer the accumulated observation data.

The master mobility 51M is a UAV4 equipped with a radio wave transmitter/receiver 52M. On the other hand, the first slave mobility 51S1 has a radio wave transmitter/receiver 52S mounted on the UAV4. Similarly, the second slave mobility 51S2, third slave mobility 51S3, fourth slave mobility 51S4, fifth slave mobility 51S5, sixth slave mobility 51S6, seventh slave mobility 51S7, and eighth slave mobility 51S8 are also connected to the radio wave transceiver 52S. is mounted on a UAV4. The slave radio wave transmitter/receiver 52S and the master radio wave transmitter/receiver 52M will be described below with reference to FIG.

FIG. 9(A) shows a schematic configuration of a radio wave transmitter/receiver 52S for slave mobility 51S. Since the radio wave transmitter/receiver 52S for the slave mobility 51S does not need the function of emitting a beam by itself, only the receiving function is shown in FIG. It is also possible to have a transmission function that can perform similar phase correction.A transmission function that uses spatio-temporal difference information to correct the phase during transmission, and a reception function that allows the spatio-temporal difference information to be used to correct the phase of the received signal. If used as a radio wave transmitter/receiver, it can be used as a distributed phased array antenna system 1, 1', 1'' or as a distributed electromagnetic wave observation data collection system 5, making it highly versatile. In FIGS. 9(A) and 9(B), the same functions as the radio wave transmitter/receiver 2 in FIG. 1(B), the radio wave transmitter/receiver 2' in FIG. 5, and the radio wave transmitter/receiver 2'' in FIG. The explanation will be omitted.

The radio wave transceiver 52S includes one communication antenna 21, a spatio-temporal difference information acquisition section 28, a transmission/reception module 22 as a signal reception section corresponding to the communication antenna 21, and a received data transmission section 524. , a reference oscillator 26 that generates a reference frequency signal. The signal received by the transmitting/receiving module 22 is converted to an easy-to-handle intermediate frequency or the like by a down converter 521, further converted to a digital signal by an A/D converter 522, and inputted to a transmitting/receiving controller 523S. Although beamforming processing using received signals obtained from a plurality of antennas can be implemented using analog circuits, digital signal processing is more flexible and more practical.

On the other hand, the spatiotemporal difference information acquisition unit 28 transmits and receives codes to and from the other radio wave transceiver 52S or the radio wave transceiver 52M by wireless communication using a synchronization antenna 27 different from the communication antenna 21. Based on the time difference of the reference oscillator 26 and the propagation delay time associated with code transmission and reception, time difference information, which is the time error between the reference radio wave transceiver 52S, 52M and the own device, and the reference radio wave transceiver Spatial difference information, which is a spatial error between the proper position of the own aircraft with respect to 52S and 52M and the current position of the own aircraft, is measured, and spatio-temporal difference information including temporal difference information and spatial difference information is obtained. This spatio-temporal difference information is input to the transmission/reception control section 523S. Note that a reference device is selected from the radio wave transmitter/receiver 52M in the master mobility 51M and the radio wave transmitter/receiver 52S in all the slave mobilities 51S, and the reference oscillator 26 of the selected reference device is used as the master clock, and the other radio wave transmitters/receivers 52M , 52S, no time error will occur in the received signal, so only the spatial difference information may be acquired as the spatio-temporal difference information.

The transmission/reception control unit 523S, which has received the received signal and the spatio-temporal difference information as described above, sends the digitized received signal and the spatio-temporal difference information at the reception timing as a set to the received data transmitter 524. hand over. The received data transmitting unit 524 is set to be able to distinguish between the received signal received by the transmitting/receiving module 22 as a receiving unit, the spatio-temporal difference information at the reception timing, and the own device and other radio wave transmitting/receiving devices 52S and 52M. The received data linked with the unique information of the own device (for example, an arbitrarily set ID number, a chip ID unique to the transmitting/receiving module 22, etc.) is sent to the master mobility 51M via the received data transmission antenna 525. is transmitted to the radio wave transmitter/receiver 52M.

Note that when a plurality of communication antennas 21 and corresponding receiving sections (transmission/reception module 22, down converter 521, A/D conversion section 522) are provided together, the received data transmission section 524 is the radio wave transceiver 52S. The received data may also include information that allows identification of each receiving section. In addition, a mobile object position control section 523a is provided in the transmission/reception control section 523, and the UAV 4 as a mobile object is moved so as to correct its own position based on the spatial difference information of the spatio-temporal difference information. Control may also be performed to bring the position closer to the appropriate position.

FIG. 9B shows a schematic configuration of the radio wave transceiver 52M of the master mobility 51M to which received data is transmitted from the radio wave transceiver 52S of the slave mobility 51S described above.

Reception data received from each radio wave transmitter/receiver 52S via the observation data reception antenna 526 and the observation data reception section is accumulated in the observation data storage section 523b as observation data. The master mobility 51M only needs to have the function of collecting observation data and transmitting it to the data collection site, but the radio wave transmitter/receiver 52S is equipped with a receiving section ( A transmitting/receiving module 22, a down converter 521, and an A/D converter 522) are provided. Therefore, the received signal received by the radio wave transceiver 52M, the spatio-temporal difference information, and the unique information of the radio wave transceiver 52M are also accumulated in the observation data storage unit 523b as observation data.

Then, when the transmission/reception control unit 523M determines that a predetermined data transfer timing has arrived, the mobile body position control unit 523a instructs the UAV 4 as a mobile body to move to a lower altitude, and connect the observation data transmission unit 528 and the observation data transmission Observation data is transferred to a data collection site via antenna 529. When the observation data transfer is completed, the master mobility 51M returns to the predetermined observation position and resumes radio wave observation.

In this way, the distributed electromagnetic wave observation data collection system 5 using the master mobility 51M with the radio wave transceiver 52M mounted on the UAV 4 and the first to eighth slave mobilities 51S1 to 51S8 with the radio wave transceiver 52S mounted on the UAV 4, each By using the spatio-temporal difference information acquired by the radio wave transceivers 52M and 52S as correction information, it is possible to suppress a decrease in beam quality. That is, the observation data collection station CP that has received the observation data corrects the phase of the received signals of the observation data collected by the master mobility 51M and the first to eighth slave mobilities 51S1 to 51S8 based on their respective spatiotemporal difference information. By doing so, it is possible to generate a high-quality reception beam by increasing the accuracy of the received signals and performing appropriate phase shift processing and appropriate weighting processing on the highly accurate reception signals and combining them. The spatio-temporal difference information acquisition unit 28 provided in the radio wave transceivers 52S, 52M may acquire the current relative position of the own device with respect to the reference radio wave transceivers 52S, 52M as spatial difference information. The observation data collection station CP, which has received the observation data from the master mobility 51M, can grasp the relative positions of the other radio wave transceivers 52S, 52S with respect to the reference radio wave transceivers 52S, 52S in the observation data each time radio waves are received. This is because it is possible to perform appropriate phase shift processing and appropriate weighting processing that take into account the relative positional deviation of the radio wave transceivers 52S and 52M.

In addition, an example in which the radio wave transmitter/receiver 2, 2', 2'', 52M, 52S that can acquire spatiotemporal difference information is used in the distributed phased array antenna system 1, 1', 1'' and the distributed electromagnetic wave observation data collection system 5 is shown. Although shown above, it can also be used as a passive radar or an active radar. Radars with larger apertures have higher resolution, but it is not easy to manufacture and operate large aperture radars. However, if it is a distributed radar like the above-mentioned radio wave transmitter/receiver 2, 2', 2'', 52M, 52S, manufacturing and operation will be easier. FIG. 10 shows a distributed synthetic aperture radar system 6 applied to a synthetic aperture radar (SAR) that can generate a two-dimensional image by processing a received signal obtained by repeatedly transmitting and receiving pulses while moving.

The distributed synthetic aperture radar system 6 includes, for example, a master synthetic aperture radar device 61M, a first slave synthetic aperture radar device 61S1, a second slave synthetic aperture radar device 61S2, and a phase control device 64. The master synthetic aperture radar device 61M includes a radio wave transmitter/receiver 62M mounted on a UAV4 as a mobile object. The first slave synthetic aperture radar device 61S1 and the second slave synthetic aperture radar device 61S2 include a radio wave transmitter/receiver 62S mounted on a UAV 4 as a mobile body. The phase control device 64 is formed by mounting the synthetic aperture radar signal processing device 63 on the UAV 4 as a moving object.

The flight direction of the master synthetic aperture radar device 61M is the azimuth direction, and the master synthetic aperture radar device 61M is designed for observation so that the observation area OA as an image acquisition area is formed in the ground range direction perpendicular to the azimuth direction. Repeatedly transmits the pulse signal and receives the reflected signal. The first slave synthetic aperture radar device 61S1 and the second slave synthetic aperture radar device 61S2 are arranged in line with the master synthetic aperture radar device 61M in an arrangement direction parallel to the ground range direction, and are in the same observation area as the master synthetic aperture radar device 61M. The pulse signal is repeatedly transmitted to the OA and the reflected signal is received. That is, the radiation beam BM of the master synthetic aperture radar device 61M, the radiation beam BS1 of the first slave synthetic aperture radar device 61S1, and the radiation beam MS2 of the second slave synthetic aperture radar device 61S2 are equally radiated to the observation area OA, and are radiated in the azimuth direction. The observation area OA gradually shifts to (slip mapping). Further, the separation between the master synthetic aperture radar device 61M, the first slave synthetic aperture radar device 61S1, and the second slave synthetic aperture radar device 61S2 is about several tens of centimeters to several meters, and the flying altitude is several hundred meters. If so, it can be considered that a pulse signal is transmitted from a single radiation source from the observation area OA. Note that the number of slave synthetic aperture radar devices 61S is not limited to two, and may be one or three or more.

The movement control device 64 is flying following the master synthetic aperture radar device 61M and the first and second slave synthetic aperture radar devices 61S1 and 61S2, and the movement control device 64 is flying following the master synthetic aperture radar device 61M and the first and second slave synthetic aperture radar devices 61S1 and 61S2. Receive data from radar devices 61S1 and 61S2. The synthetic aperture radar signal processing device 63 that receives the received data from the master synthetic aperture radar device 61M and the first and second slave synthetic aperture radar devices 61S1 and 61S2 processes the received data to generate a two-dimensional image. As processing processing by the synthetic aperture radar signal processing device 63, for example, correlation processing is performed between a reference signal (part of a chirp pulse) and a reflected signal obtained by transmitting a frequency-modulated chirp signal to the observation area OA. By doing so, the ground range direction is resolved, and the correlation between the reference wave and the received signal is calculated by taking into account the Doppler effect due to the flight speed of the master synthetic aperture radar device 61M and the first and second slave synthetic aperture radar devices 61S1 and 61S2. The azimuth direction is resolved by executing the process.

Next, detailed functions of the master synthetic aperture radar device 61M, the first to M-th slave synthetic aperture radar devices 61S1 to 61Sm, and the phase control device 64 that constitute the distributed synthetic aperture radar system 6 will be explained based on FIG.

For example, the radio wave transmitter/receiver 62M of the master synthetic aperture radar device 61M includes a pulse transmitter/receiver 622 that transmits and receives pulse signals via a communication antenna 621. In addition, by wireless communication using a synchronization antenna 6231 that is different from the communication antenna 621, codes are exchanged with other radio wave transceivers 62S, and the time difference between the reference oscillators 624 and the propagation delay due to the code transmission and reception are performed. Based on the time difference information, which is the time error with the reference radio wave transmitter/receiver 62S, and the spatial error between the appropriate position of the own aircraft and the current position of the own aircraft with respect to the reference radio wave transmitter/receiver 62S. It includes a spatio-temporal difference information acquisition unit 6232 that measures certain spatial difference information and acquires spatio-temporal difference information including temporal difference information and spatial difference information.

However, in the distributed synthetic aperture radar system 6 of this embodiment, the reference oscillator 624 of the radio wave transmitter/receiver 62M in the master synthetic aperture radar device 61M is selected as the master clock, and the first to Mth slave synthetic aperture radar devices 61S1 to In order to synchronize the reference oscillator 624 of the 61Sm radio wave transmitter/receiver 62S, the synchronization control unit 6233 controls the spatio-temporal difference information acquisition unit 6232 to perform phase shift detection using the reference oscillator 624 as a master clock. Therefore, the spatiotemporal difference information acquisition unit 6232 of the radio wave transmitter/receiver 62M does not acquire temporal difference information, and only the spatial difference information is stored in the spatiotemporal difference information storage unit 625. Furthermore, when detecting spatial difference information of other radio wave transceivers 62S based on the flight position of the master synthetic aperture radar device 61M, the spatio-temporal difference information acquisition unit 6232 of the radio wave transceiver 62M uses the spatial difference information Detection also disappears. Note that when storing the spatio-temporal difference information in the spatio-temporal difference information storage unit 625, a time stamp is also stored so that the storage timing becomes clear.

The pulse transmitting/receiving section 622 generates a frequency-modulated chirp signal by the chirp pulse generating section 6221, and emits the pulse signal from the communication antenna 621 driven to an appropriate radiation position by the antenna driving section 6222. The reflected signal reflected by the observation object is received by the reflected signal receiving section 6223 and stored in the reflected signal accumulating section 626. At this time, time stamps are stored together to make the storage timing of the reflected signal clear.

The received data transmitting unit 6271 then transmits the reflected signal received by the pulse transmitting/receiving unit 622 and stored in the reflected signal storage unit 626, the spatiotemporal difference information stored in the spatiotemporal difference information storage unit 625, and the radio wave transmitter/receiver. 62M of unique information is transmitted as received data to the synthetic aperture radar signal processing device 63 of the mobile control device 64. Note that the synthetic aperture radar signal processing device 63 can determine the correspondence between the reflected signal and the spatio-temporal difference information based on their respective time stamps.

On the other hand, the radio wave transceivers 62S of the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm have almost the same configuration as the radio wave transceivers 62M in the master synthetic aperture radar device 61M described above, so the same functions are denoted by the same reference numerals. The explanation will be omitted and only the different points will be explained below.

The spatiotemporal difference information acquisition unit 6232 of the radio wave transceiver 62S acquires temporal difference information using the reference oscillator 624 of the radio wave transceiver 62M as a master clock through wireless communication using the synchronization antenna 6231, and calculates the temporal error. The synchronization control unit 6233 controls the reference oscillator 624 to correct it. Thereby, the reference oscillator 624 of the radio wave transceiver 62S is synchronized with the reference oscillator 624 of the radio wave transceiver 62M. Therefore, the phases of the chirp pulses generated by the chirp pulse generation section 6221 of the radio wave transmitter/receiver 62S of the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm can be aligned with high precision. That is, when pulse signals are simultaneously emitted toward the observation area OA from the master synthetic aperture radar device 61M and the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm, a high-power chirped pulse is emitted from an apparent single antenna. As a result, the reception level of the reflected signal from the observation target increases, and the influence of noise can be reduced. In addition, since the master synthetic aperture radar device 61M and the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm simultaneously receive the reflected signal from the observation target, the reflected signal is apparently received by a large-diameter antenna. That will happen.

Note that the control functions (flight speed, direction control of the communication antenna 621, etc.) in the distributed synthetic aperture radar system 6 may be provided in the master synthetic aperture radar device 61M, or may be provided in the movement control device 64. I do not care.

The synthetic aperture radar signal processing device 63 of the movement control device 64 receives signals from the master synthetic aperture radar device 61M and the first to M-th slave synthetic aperture radar devices 61S1 to 61Sm via the data receiving antenna 631 and the wireless communication unit 632. Get received data. A phase adjustment section 633 performs phase adjustment for correcting a spatial error based on spatial difference information in the spatio-temporal difference information on the reflected signal in the received data from the master synthetic aperture radar device 61M. Thereby, received data of the master synthetic aperture radar device 61M with spatial errors corrected based on the spatio-temporal difference information is obtained. Similarly, the phase adjustment unit performs phase adjustment to correct the spatial error based on the spatial difference information in the spatiotemporal difference information with respect to the reflected signals in the received data from the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm. Do it at 633. As a result, received data of the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm with phase shifts corrected based on the spatio-temporal difference information is obtained.

As described above, the reflected signals received simultaneously by the master synthetic aperture radar device 61M and the first to Mth slave synthetic aperture radar devices 61S1 to 61Sm can be regarded as data of the same observation area OA. By adjusting the phase of these simultaneously acquired reflected signals and combining them to form composite received data, the influence of irregular noise can be reduced. Therefore, if the correlation processing execution unit 634 performs correlation processing on the combined received data and resolves it, it becomes possible to obtain a highly accurate two-dimensional image.

Note that, as in the distributed synthetic aperture radar system 6' shown in FIG. 12, chirp pulses are emitted only by the master synthetic aperture radar device 61M, and the radio waves of the first to M-th slave synthetic aperture radar devices 61S1' to 61Sm' are The transceiver 62S' may be configured to only receive pulses. In this case, the function of synchronizing the reference oscillator 624 with the master clock is not required in the radio wave transmitter/receiver 62S', and the pulse transmitting function of the pulse transmitting/receiving section 622 may not be used. Alternatively, a pulse receiving section 628 may be provided in place of the pulse transmitting/receiving section 622, and a configuration may be adopted in which only the antenna driving section 6281 that drives the communication antenna 621 and the reflected signal resin section 6282 are provided. In this distributed synthetic aperture radar system 6' as well, if the reflected signals received simultaneously by the master synthetic aperture radar device 61M and the first to M-th slave synthetic aperture radar devices 61S1' to 61Sm' are combined and correlation processing is performed, It becomes possible to obtain highly accurate two-dimensional images.

The embodiments of the radio wave transmitter/receiver, the distributed phased array antenna system, the distributed electromagnetic wave observation data collection system, and the distributed synthetic aperture radar system according to the present invention have been described above based on the accompanying drawings. The present invention is not limited to the embodiments, and may be implemented by reusing known and existing equivalent technical means as long as the configuration described in the claims is not changed.

1 Distributed phased array antenna system 2 Radio wave transmitter/receiver 21 Communication antenna 24 Phase adjustment section 26 Reference oscillator 28 Spatiotemporal difference information acquisition section

Claims (6)

A radio wave transmitter/receiver that can be used as an antenna element that configures a phased array antenna system that obtains desired directivity by arranging a plurality of antenna elements,
comprising N communication antennas (N is any natural number), a spatiotemporal difference information acquisition section, a phase shift adjustment section, and a reference oscillator that generates a reference frequency signal,
The spatiotemporal difference information acquisition unit transmits and receives codes to and from the other radio wave transmitter/receiver by wireless communication using a synchronization antenna different from the communication antenna, and calculates the time difference between the reference oscillators. Based on the propagation delay time associated with the code transmission and reception, time difference information, which is the time error between the reference radio wave transmitter and receiver and the own aircraft, and the appropriate position of the own aircraft with respect to the reference radio wave transmitter and receiver, are determined. measuring spatial difference information that is a spatial error with the current position of the aircraft, and acquiring spatiotemporal difference information including the temporal difference information and the spatial difference information;
The phase shift adjustment unit adjusts the amount of phase shift of radio waves radiated from the communication antenna based on the spatio-temporal difference information so as to correct the temporal error and/or the spatial error.
A radio wave transmitter/receiver characterized by: The phased array antenna system is configured by using a plurality of the radio wave transmitters and receivers according to claim 1, and has a specific directivity by superimposing radio waves radiated from the communication antenna of each radio wave transmitter and receiver. A distributed phased array antenna system featuring: By arranging multiple antenna elements and performing appropriate phase shift processing and appropriate weighting (amplitude amplification/attenuation) processing on the received signals received by each antenna element and combining them, receive beams with various directivity can be generated. A radio wave transmitter/receiver that can be used as each antenna element in a beamforming antenna that can be formed,
N communication antennas (N is any natural number), a spatio-temporal difference information acquisition unit, N signal reception units corresponding to each communication antenna, a received data transmission unit, and a reference frequency signal is generated. a reference oscillator;
The spatiotemporal difference information acquisition unit transmits and receives codes to and from the other radio wave transmitter/receiver by wireless communication using a synchronization antenna different from the communication antenna, and calculates the time difference between the reference oscillators. Based on the propagation delay time associated with the code transmission and reception, time difference information that is the time error between the reference radio wave transmitter and receiver and the own aircraft, and the current relative position of the own aircraft with respect to the reference radio wave transmitter and receiver. measuring spatial difference information, and acquiring spatio-temporal difference information including the temporal difference information and the spatial difference information,
The received data transmitting unit includes the received signal received by the signal receiving unit, the spatio-temporal difference information at the reception timing, and the unique information of the own device that is set to be able to distinguish between the own device and the other radio wave transmitter/receiver. Send the received data linked with the information to outside the aircraft,
A radio wave transmitter/receiver characterized by: A plurality of slave mobility comprising the radio wave transmitter/receiver according to claim 3 mounted on a mobile body,
A master mobility comprising at least a data relay machine mounted on a mobile body that collects the received data transmitted from a plurality of the slave mobilities and collectively transfers the collected received data to a predetermined data collection site;
including;
A plurality of the slave mobilities and the master mobility are arranged in an arbitrarily set electromagnetic wave observation area, and only the master mobility that has collected the received data from each slave mobility collects the collected received data as electromagnetic wave observation data. A distributed electromagnetic wave observation data collection system that transmits data to a collection center. A synthetic aperture system that can generate a two-dimensional image by processing the received signal obtained by arranging multiple antenna elements and repeatedly transmitting and receiving pulses while moving in the azimuth direction above the image acquisition area using a synthetic aperture radar signal processing device. A radio wave transmitter/receiver that can be used as each antenna element in radar,
N communication antennas (N is an arbitrary natural number), N pulse transmission/reception units corresponding to each communication antenna, a spatiotemporal difference information acquisition unit, a received data transmission unit, and generates a reference frequency signal. a reference oscillator;
The spatiotemporal difference information acquisition unit transmits and receives codes to and from the other radio wave transmitter/receiver by wireless communication using a synchronization antenna different from the communication antenna, and calculates the time difference between the reference oscillators. Based on the propagation delay time associated with the code transmission and reception, time difference information, which is the time error between the reference radio wave transmitter and receiver and the own aircraft, and the appropriate position of the own aircraft with respect to the reference radio wave transmitter and receiver, are determined. measuring spatial difference information that is a spatial error with the current position of the aircraft, and acquiring spatiotemporal difference information including the temporal difference information and the spatial difference information;
The received data transmitter is configured to be able to distinguish between the own device and the other radio wave transmitter/receiver by the reflected signal received by the pulse transmitter/receiver and the spatio-temporal difference information acquired by the spatio-temporal difference information acquirer. transmitting the unique information of the own aircraft as received data to the synthetic aperture radar signal processing device;
A radio wave transmitter/receiver characterized by: A master synthetic aperture radar device equipped with the radio wave transmitter/receiver according to claim 5 on a moving body, and configured to transmit a pulse signal to the image acquisition area and receive a reflected signal;
M units (M is an arbitrary natural number) in which the radio wave transmitter/receiver according to claim 5 is mounted on a moving object, and transmit a pulse signal and receive a reflected signal to the same image acquisition area as the master synthetic aperture radar device. a slave synthetic aperture radar device,
a synthetic aperture radar signal processing device that processes received data from the master synthetic aperture radar device and the slave synthetic aperture radar device to generate a two-dimensional image;
including;
The slave synthetic aperture radar device acquires the spatiotemporal difference information using the master synthetic aperture radar device as the radio wave transmitter/receiver as a reference, and performs phase adjustment to correct the temporal error based on at least the temporal difference information. By doing this, a pulse signal is transmitted in synchronization with the pulse transmission of the master synthetic aperture radar device,
The synthetic aperture radar signal processing device processes a reflected signal in the received data from the master synthetic aperture radar device and/or the slave synthetic aperture radar device based on at least the spatial difference information in the spatiotemporal difference information. performing phase adjustment to correct the spatial error;
A distributed synthetic aperture radar system characterized by: