Radio wave propagation control system

Abstract

To provide a radio wave propagation control system that, when carrying out an evaluation test of different radar devices, can guarantee equality and efficiently carry out the evaluation test.SOLUTION: A radio wave propagation control system 1 has: a phantom unit 20; a variable load unit 30 that is connected to an antenna element 21 and changes a reflection coefficient Γ of radio waves; a memory 41 that stores radio wave information in a radio wave propagation path between a radar device 10 and the phantom unit 20, and radio wave information in a radio wave propagation path between the radar device 10 and an object to be measured; a control unit 42 that sets the reflection coefficient of the variable load unit 30 to a predetermined value. The control unit 42 adjusts the reflection coefficient of the variable load unit 30 so as to bring a phase and an amplitude constituting first propagation path information in a radio wave propagation path between the antenna element 21 and the radar device 10, closer to a phase and an amplitude constituting second propagation path information in the radio wave propagation path between the radar device 10 and the object to be measured.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a radio wave propagation control system.

Background Art

[0002] Sensing technology for an object using radar is known (see Prior Art Document 1 below). In the evaluation of a plurality of different radar devices (for example, sensing performance evaluation), generally, the same measurement object is installed at a location separated by a predetermined distance in each of the plurality of different radar devices, a test signal is emitted from each radar device to the same measurement object, a reflected wave (round-trip propagation path information) from the measurement object is received, and the received data is analyzed by a computer connected to the radar device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the measurement object is a person each time of measurement, it is difficult to reproduce the same biological activity, and it is realistically impossible to ensure equality when conducting an evaluation test (benchmark test) of different radar devices. Further, when the measurement locations are different and the measurement object is a heavy object such as a car, it is difficult to efficiently conduct the evaluation test in consideration of the movement of the measurement object and the like.

[0005] In view of the above problems, an object of the present invention is to provide a radio wave propagation control system capable of ensuring equality and efficiently conducting an evaluation test when conducting an evaluation test of different radar devices.

Means for Solving the Problems

[0006] The radio wave propagation control system 1 of the present invention is a radio wave propagation control system 1 having a phantom unit 20 composed of at least one or more antenna elements 21 that transmit and receive radio waves emitted from a radar device 10. The system is provided with a variable load capable of changing the amplitude and phase of the reflection coefficient (Γ) of the radio wave, and includes a variable load unit 30 that changes the reflection coefficient Γ of the radio wave (configured to include phase and amplitude information), a memory unit 41 that stores the phase and amplitude information of the propagation path information (first propagation path information) in the radio wave propagation path between the radar device 10 and the phantom unit 20, and the phase and amplitude information of the propagation path information (second propagation path information) in the radio wave propagation path between the radar device 10 and the measurement object, and a control unit 42 that sets the reflection coefficient of the variable load unit 30 to a predetermined value. The control unit 42 adjusts the reflection coefficient Γ of the variable load unit based on the first propagation path information and the second propagation path information so that the phase and amplitude (propagation path information) constituting the first radio wave information (radio wave information with controlled phase and amplitude) of the radio wave emitted from the antenna element 21 to the radar device 10 approach the phase and amplitude (propagation path information) constituting the second radio wave information in the radio wave propagation path between the radar device 10 and the measurement object, which have been measured in advance.

Advantages of the Invention

[0007] According to the radio wave propagation control system of the present invention, equality can be ensured and the evaluation test can be efficiently performed when conducting evaluation tests on different radar devices.

Brief Description of the Drawings

[0008]

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[0009] The configuration of the radio wave propagation control system 1 according to the embodiment will be described below with reference to the drawings. In the following detailed description, representative embodiments that disclose specific details are described in order to enable a complete understanding of one embodiment according to the present teachings. In order to avoid obscuring the description of the representative embodiments, descriptions of known systems, devices, operating methods, and manufacturing methods may be omitted. Nevertheless, systems, devices, and methods within the scope of understanding of those skilled in the art are within the scope of the present teachings and may be used in accordance with the representative embodiments. It should be understood that the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to be limiting.

[0010] In this specification, terms such as first, second, third, etc. may be used to describe various elements or components, but it should be understood that these elements or components should not be limited by these terms. These terms are used only to distinguish one element or component from another.

[0011] Unless otherwise specified, when an element or component is said to be "connected to" another element or component, these terms include cases where one or more intermediate elements or components may be utilized to connect the two elements or components. However, when an element or component is said to be "directly connected to" another element or component, this includes only cases where the two elements or components are connected to each other without using any intermediate or intervening elements or components.

[0012] The radio wave propagation control system 1 includes a phantom unit 20 that passively (in the sense of not being active) performs transmission and reception of radio waves emitted from a radar device under test (hereinafter referred to as the "radar device") 10, a variable load unit 30 that changes the reflection coefficient Γ (configured to include phase and amplitude information) of the radio waves, and a computer 40 that sets the reflection coefficient of the variable load unit 30 to a predetermined value. The radio wave propagation control system 1 is configured to control the reflection coefficient (described later) for reconstructing the phase and amplitude information (propagation path information, channel information) of the radio waves between the radar device 10 and the phantom unit 20 by the computer 40, so as to appropriately evaluate the performance of the radar device 10 that is the object under test.

[0013] [Radar device] The radar device 10 has a transmitter 12 that emits radio waves and a receiver 14 that receives the radio waves reflected by the measurement object. Since this type of radar device is well-known, a detailed description thereof is omitted.

[0014] [Phantom unit] As shown in FIG. 1, the phantom unit 20 is configured by arranging a plurality of antenna elements (antenna modules) 21 in a matrix on a substrate, enabling the manipulation of the reflection characteristics and refraction characteristics of electromagnetic waves. As this phantom unit 20, for example, a RIS (: Reconfigurable Intelligent Surface) that utilizes "metamaterial - metasurface technology" can be mentioned. Each antenna element can control the radio wave propagation characteristics (broadly referred to as the "propagation channel") through variable load control. Since the RIS is publicly known, a detailed description thereof will be omitted. In the embodiment, a variable load circuit 30 described later is connected to the antenna elements constituting the RIS, and the radio wave propagation characteristics emitted from the phantom unit 20 are reconfigured by controlling the reflection coefficient of the variable load circuit 30.

[0015] On the other hand, a conventional phantom unit is known to include a plurality of small radar target simulators (MRTS), and each MRTS includes a receiving antenna, a variable gain amplifier (VGA: Variable Gain Amplifier), an in - phase quadrature (IQ) mixer, a variable attenuator, and a transmitting antenna. It can be seen that the phantom unit 20 of the embodiment has a simple configuration without components such as a variable gain amplifier, which are components of the conventional phantom unit.

[0016] [Variable Load Section] As shown in Fig. 3, the variable load unit 30 is configured to include a variable attenuator 130 capable of controlling the amplitude of the reflection coefficient and a variable phase shifter 131 capable of controlling the phase. The example shown in Fig. 3 is one configuration example of the variable load unit 30. In the example of Fig. 3, the variable attenuator 130 and the variable phase shifter 131 each have one form, but this is an example when there is only one antenna element 21 constituting the phantom unit 20. When there are a plurality of antenna elements 21 (antenna elements 21-1 to 21-n), the variable load unit 30 composed of the variable attenuator 131 and the variable phase shifter 132 is provided in a number corresponding to the number of antenna elements. In the variable load unit configured in this way, by independently controlling the variable attenuator 130 and the variable phase shifter 131, the amplitude and phase of the reflection coefficient of the variable load unit seen from the antenna element 21 can be independently controlled.

[0017] The example shown in Fig. 4 is another configuration example of the variable load unit 30. The variable load unit 30 is configured to include a hybrid coupler 38 and variable phase shifters 36 and 37. The hybrid coupler 38 has a first port 31, a second port 32, a third port 33, and a fourth port 34. The antenna 21 of the phantom unit 20 is connected to the first port 31, a termination resistor 35 equal to the reference impedance is connected to the second port 32, and independently controllable variable phase shifters 36 and 37 are connected to the third and fourth ports 33 and 34, respectively. The other terminals of the variable phase shifters 36 and 37 are set to a short-circuit end or an open end. The variable phase shifter 36 can be replaced with a variable reactance, for example, it can be replaced with a variable reactance configured by connecting varactor diodes 36-1 and 36-2 in parallel as shown in Fig. 5. The variable phase shifter 37 can be replaced with a variable reactance, for example, it can be replaced with a variable reactance configured by connecting varactor diodes 37-1 and 37-2 in parallel. In the variable load unit configured in this way, by independently controlling the variable phase shifters (variable reactances) 36 and 37, the amplitude and phase of the reflection coefficient of the variable load unit seen from the first port 31 can be independently controlled.

[0018] As still another example of the variable load unit 30, a variable phase shifter may be used instead of the variable reactor in FIG. 4.

[0019] By changing the voltage that reverse-biases the varactor diode, the capacitance of the varactor diode can be changed. At this time, a DC voltage is applied to the hybrid coupler side, and DC cut capacitors 71 and 72 are inserted between the third port 33 and the variable reactor 36 and between the fourth port 34 and the variable reactor 37 so that no DC current flows through the first and second ports 31 and 32. Further, RF choke inductors and / or resistors 73 and 74p are inserted on the DC bias power supply 73 and 74 sides so that the radio waves incident from the antenna 21 do not enter the DC bias power supplies 73 and 74.

[0020] [Computer] As shown in FIG. 2, the computer 40 includes a memory unit 41, a control unit 42, a calculation unit (arithmetic unit) 43, and a communication unit 44. Note that the calculation unit 43 may be configured to be included in the control unit 42. The memory unit 41 stores instruction information for the variable load unit 30 and target reconstruction information that has been pre-reconstructed in advance. The target reconstruction information is propagation path information between the radar device and the measurement object obtained by irradiating the measurement object to be reconstructed in advance with radar from the radar device. Details will be described later.

[0021] [Reconstruction algorithm] With reference to the pre-acquired propagation path information (hereinafter referred to as "target reconstruction information") stored in the memory unit of the embodiment, the value of the reflection coefficient to be set in the variable load unit is calculated by the calculation unit, and the calculated reflection coefficient is set from the control unit to the variable load, whereby the propagation path state can be controlled to reproduce the target reconstruction information.

[0022] Further, the embodiment applies a propagation path reconstruction algorithm to a bistatic MIMO (Multiple-Input Multiple-Output) radar. "Bistatic" means that the antennas used by the transmitter and the receiver are different and are installed at different positions, and "MIMO" means that it includes a plurality of transmitters and a plurality of receivers, and each transmitter and each receiver are equipped with one antenna each. That is, a "bistatic MIMO radar" refers to a radar in which the antennas used by the transmitter and the receiver are different, are installed at different positions, and a plurality of such antennas are used. In the embodiment, a bistatic MIMO radar will be described as an example, but it is also applicable to a "monostatic radar" in which the transmitter and the receiver share an antenna.

[0023] The method for reproducing target reconstruction information according to the embodiment will be described below according to the control flow of the propagation path state between the radar device 10 and the phantom unit 30.

[0024] The description will be made according to the control flowchart of the propagation path state shown below. (Step 1) The memory unit 41 acquires and stores the propagation path information between the transmitter and the receiver when the object exists. (Step 2) The calculation unit 43 refers to the propagation path information acquired and stored in Step 1 and calculates the reflection coefficient to be set in the variable load unit 30. (Step 3) The control unit 42 controls the reflection coefficient of the variable load unit 30 based on the reflection coefficient calculated in Step 2 and controls the propagation path state between the radar device 10 and the phantom unit 20.

[0025] [Step 1] As shown in FIG. 6, for the measurement object, a signal for propagation path measurement is emitted from the antenna 13 of the transmitter 12 constituting the radar device 10, and based on the signal for propagation path measurement received by the antenna 15 of the receiver 14 constituting the radar device 10, the propagation path information between the transmitter 12 and the receiver 14 when the measurement object exists is measured.

[0026] In a conventional system, when the state of a measurement object changes over time, it has been difficult to reproduce the state of the propagation path between a transmitter and a receiver when the measurement object exists at a specific time. On the other hand, in the system according to the embodiment, as will be described later, the propagation path information between the transmitter and the receiver when the object exists at a certain time is acquired and stored, and by referring to this and controlling the radio wave propagation control device, it is possible to reproduce the propagation path information between the transmitter and the receiver acquired in advance.

[0027] [Steps 2 and 3] The calculation unit 43 calculates the reflection coefficient of the variable load unit 30 connected to the phantom unit 20 so that a predetermined propagation path information matches the propagation path information between the transmitter 12 and the receiver 14 via the phantom unit 20. The method for deriving the reflection coefficient of the variable load unit 30 will be described below.

[0028] By optimizing the reflection coefficient of the variable load so as to minimize the norm (for example, the Frobenius norm) of the difference between "the propagation path matrix between the transmitter 12 and the receiver 14 of the radar device 10 via the phantom unit 20" and "the propagation path matrix between the radar device 10 and the measurement object measured in advance", the predetermined propagation path information and the propagation path information between the transmitter 12 and the receiver 14 via the phantom unit 20 are made to match as much as possible.

[0029] The propagation path matrix between the transmitter and the receiver when the phantom unit 20 is installed can be approximated as shown in the following mathematical formula (1). H RT represents the propagation path matrix between the transmitter and the receiver "not passing through" the phantom unit 20 (hereinafter referred to as the "direct propagation path matrix" and sometimes referred to as the "direct propagation path information"). H PT represents the propagation path matrix between the transmitter 12 constituting the radar device 10 and the phantom unit 20 (hereinafter referred to as the "forward propagation path matrix" and sometimes referred to as the "forward propagation path information"). H RPrepresents the propagation path matrix (hereinafter referred to as the "complex propagation path matrix" and sometimes called the "complex propagation path information") between the phantom unit 20 and the receiver 14 that constitutes the radar device 10, and they are in a mutually inverse relationship. Here, the S representing the mismatch and mutual coupling of the antenna elements 21 of the phantom unit 20 PP is considered to be negligible enough, and the propagation path control will be described below. H PT and the acquisition of information on H RP will be described later. Here, the superscript T represents the transpose of a matrix.

Number

[0030] The reflection coefficient Γ is a diagonal matrix having the reflection coefficients of the variable load units 30 connected to the respective antenna elements 21 of the phantom unit 20 as diagonal elements. Thus, the propagation path matrix between the transmitter 12 and the receiver 14 when the phantom unit 20 is installed is the propagation path matrix H between the transmitter and the receiver that does not "pass through" the phantom unit 20 RT and the propagation path matrix between the transmitter 12 and the receiver 14 that "passes through" the phantom unit 20 (the propagation path matrix H between the transmitter and the phantom unit 20 PT and the diagonal matrix Γ having the reflection coefficients of the variable load unit 30 as diagonal terms and the propagation path matrix H between the phantom unit 20 and the receiver 14 RP and the product) can be expressed as the sum (see the following formula (1)).

[0031] The control unit 42 optimizes the reflection coefficient of the variable load unit 30 so as to minimize the norm (for example, the Frobenius norm) of the difference between the propagation path matrix H0 when the object exists, which is acquired in advance, and the propagation path matrix when the phantom unit 20 is installed. Thereby, the predetermined propagation path information and the propagation path information between the transmitter and the receiver via the device are made to match as much as possible. This optimization can be expressed as in the following formula (2) to obtain the reflection coefficient Γ. However, at this time, a constraint is provided such that the amplitude of the reflection coefficient of each variable load becomes a value of 1 or less.

Number

[0032] (Principle of propagation path estimation method) <Flow of propagation path estimation method> The principle of the propagation path estimation method will be described below with reference to FIG. 10. First, the reflection coefficients of the variable load unit 30 with respect to the antenna elements 21 constituting the phantom unit 20 are all set to zero. Or, the amplitude of the reflection coefficient is set to an extremely small value. At this time, the signal s for propagation path estimation is transmitted from the oscillator 5 through one antenna of the transmitter 12 constituting the radar device 10. T Then, the signal s for propagation path estimation is received by one antenna of the receiver 14 constituting the radar device, and the received signal at this time is denoted as s. T This received signal s is expressed as in the following formula (3). R This received signal s R is as follows.

Number

Number

[0033] The above-described process is applied to all combinations of all antennas of the transmitter 12 and all antennas of the receiver 14. As a result, the propagation path information h RT between all antennas 13-1 to 13-n of the transmitter 12 and all antennas 15-1 to 15-n of the receiver 14 can be estimated. As described above, the propagation path information H RT required for the optimization of the reflection coefficient based on the above-described propagation path reconstruction algorithm can be estimated.

[0034] Set the reflection coefficient of the variable load unit 30 with respect to the antenna element 21 having the phantom unit 20 to only non-zero γ (scalar value when focusing on a certain variable load), and set the reflection coefficients of other variable loads to zero or to extremely small values. Also, radio waves (S in FIG. 1) directly propagated from the antenna element 21 having the phantom unit 20 to the antenna element 21 having the phantom unit 20 PP can be ignored in the following description. Here, a signal s for propagation path estimation is transmitted from one antenna having the transmitter 12. T And the signal s for propagation path estimation is received by any one antenna constituting the receiver 14, and the received signal at this time is set as s. T This received signal can be approximated as shown in the following equation (5). R

Equation

[0035] Here, the first term inside the parentheses in Equation (5) is the propagation path information h between the antenna 13 having the transmitter 12 that "does not pass through" the phantom unit 20 and the antenna 15 having the receiver 14, and this information can be estimated as described in Equation (4) above. On the other hand, the second term inside the parentheses in Equation (5) represents the product of the propagation path information h between the antenna 13 having the transmitter 12 and the antenna element 21 of the phantom unit 20, the reflection coefficient γ of the variable load unit 30 connected to this antenna element 21, and the propagation path information h between any antenna of the phantom unit 20 and any antenna of the receiver 14 constituting the radar device 10. Therefore, from the relationship between the transmission signal and the reception signal, the product (h RT ×h PT ×h RP ) of the propagation path information between any antenna constituting the transmitter 12 and any antenna element 21 constituting the phantom unit 20 and the propagation path information between any antenna constituting the phantom unit 20 and any antenna constituting the receiver 14 is estimated as shown in the following equation (6). RP ×h PT )

Equation

[0036] Apply the above processing to all combinations of all antennas of the transmitter 12, all antennas of the receiver 14, and all antenna elements constituting the phantom unit 20. As a result, for all combinations of all antennas of the transmitter 12, all antennas of the phantom unit 20, and all antennas of the receiver 14, the propagation path information between a certain antenna of the transmitter 12 and a certain antenna 21 of the phantom unit 20, and the propagation path information between a certain antenna of the phantom unit 20 and a certain antenna of the receiver 14 are multiplied (h RP ×h PT ) can be estimated. In this way, the propagation path information H RP ΓH PT required for the optimization of the reflection coefficient based on the above-described propagation path reconstruction algorithm can be estimated.

[0037] As described above, by executing the above-described estimation process to obtain the reflection coefficient Γ that minimizes the difference between the propagation path matrix when the object is present and the propagation path matrix when the phantom unit 20 is installed, the propagation path information closest to the pre-measured propagation path information can be calculated. Therefore, after obtaining the propagation path information between the measurement object 100 and the radar device 10 once, a propagation path state approximated to a desired measurement object can be obtained only by using the radio wave propagation control system of the embodiment.

[0038] <H PT 、H RP 、H RT Information acquisition> [H PT ,H RP As shown in FIG. 7, the transmitter 12 and the receiver 14 having a transmission function that constitute the radar device 10 each have propagation path information H PT and H RP ​A test signal for measurement is transmitted, and this test signal is received by the antenna element 21 that constitutes the phantom section 20, and is received by the receiving section 50 that constitutes the phantom section 20 (note that it may be a receiving section outside the phantom section 20) via a switch (not shown), a distributor (not shown), or a coupler (not shown). The propagation path information H between the transmitter 12 and the antenna element 21 that constitutes the phantom section 20 PT and the propagation path information H between the receiver 14 and the antenna element 21 that constitutes the phantom section 20 RP are measured based on this received signal.

[0039] [H RP As shown in FIG. 8, the transmitter 12 that constitutes the radar device 10 transmits a test signal (not shown) for measuring the propagation path information H PT (not shown), and this test signal is received by the antenna element 21 that constitutes the phantom section 20, and is received by the receiving section 50 that constitutes the phantom section 20 (note that it may be a receiving section outside the phantom section 20) via a switch (not shown), a distributor (not shown), or a coupler (not shown). The propagation path information H between the transmitter 12 and the antenna element 21 that constitutes the phantom section 20 PT is measured based on this received signal. Further, in order to measure the propagation path information H RP between the receiver 14 that does not have a transmitter and constitutes the radar device 10 and the phantom section 20, the transmitting section 60 that constitutes the phantom section 20 (note that it may be a transmitting section outside the phantom section 20) transmits a test signal, and this test signal is received by the receiver 14. In this way, the propagation path information H RP between the receiver 14 and the antenna element 21 that constitutes the phantom section 20 is measured.

[0040] [H RT As shown in FIG. 9, the transmitter 12 that constitutes the radar device 10 transmits a test signal for measuring the propagation path information H RT and this test signal is received by the receiver 14 without passing through the antenna element 21. In this way, the propagation path information H between the transmitter 12 and the receiver 14​​RT is measured.

[0041] <Effect> [Effect in Embodiment] According to the radio wave propagation control system 1 according to the embodiment, there is provided a radio wave propagation control system 1 having a phantom unit 20 including at least one or more antenna elements 21 that transmit and receive radio waves emitted from the radar device 10, the phantom unit 20 being connected to a variable load unit 30 including a variable load capable of changing the amplitude and phase of the reflection coefficient of the radio wave, a memory unit 41 that stores information on the phase and amplitude of the propagation path information in the radio wave propagation path between the radar device 10 and the phantom unit 20, and information on the phase and amplitude of the propagation path information in the target radio wave propagation path between the radar device 10 and the measurement object, and a control unit 42 that sets the reflection coefficient of the variable load unit 30 to a predetermined value. The control unit 42 adjusts the reflection coefficient of the variable load unit 30 based on the first propagation path information and the second propagation path information so that the phase and amplitude constituting the first propagation path information in the radio wave propagation path between the antenna element 21 and the radar device 10 approach the phase and amplitude constituting the second propagation path information in the radio wave propagation path between the radar device 10 and the measurement object measured in advance. According to the above configuration, referring to the propagation path information acquired in advance and stored in the memory unit 41, the calculation unit 43 calculates the value of the reflection coefficient to be set in the variable load unit based on this, and the reflection coefficient of the variable load unit 30 can be set from the control unit 42 based on the calculated result. By setting (optimizing) so as to approach the propagation path information acquired in advance, the propagation path information acquired in advance is reproduced. Therefore, equality can be ensured and the evaluation test can be efficiently performed when performing evaluation tests on different radar devices. (2) According to the radio wave propagation control system 1 according to the embodiment, the phantom unit 20 has a reception function (reception unit 50) for receiving the radio wave emitted from the transmitter 12 constituting the radar device 10 and acquiring the propagation path information in the radio wave propagation path between the transmitter 12 and the antenna element 21 constituting the radar device 10 based on the received radio wave. Therefore, the reconstruction of the propagation path can be efficiently performed. (3) According to the radio wave propagation control system 1 according to the embodiment, the phantom unit 20 has a transmission unit 60 that emits radio waves, and the radio waves emitted from the antenna element 21 are received by the receiver 14 that constitutes the radar device 10, and based on the received radio waves, the propagation path information in the radio wave propagation path between the antenna element 21 and the receiver 14 that constitutes the radar device 10 is acquired. Therefore, the reconstruction of the propagation path can be efficiently performed. (4) According to the radio wave propagation control system 1 according to the embodiment, while radio waves are being emitted from the transmitter 12 that constitutes the radar device 10 and the receiver 14 that constitutes the radar device 10 is receiving the radio waves, by changing the reflection coefficient of the variable load unit 30 one or more times, the amplitude and / or phase of the radio waves received by the receiver 14 that constitutes the radar device 10 is changed, and based on the change in the amplitude and / or phase of the received radio waves, the first propagation path information is estimated. Therefore, the reconstruction of the propagation path can be efficiently performed.

[0042] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0043] 1…Radio wave propagation control system, 20…Phantom unit, 21…Antenna (antenna element), 30…Variable load unit (variable load circuit), 36, 37…Variable phase shifters, 130…Variable attenuator, 131…Variable phase shifter, 40…Computer, 41…Memory unit, 42…Control unit, 43…Calculation unit, H PT ΓH RP …First propagation path information, H0…Second propagation path information

Claims

1. A radio wave propagation control system having a phantom unit including at least one antenna that transmits and receives radio waves emitted from a radar device, a variable load unit connected to the antenna and including a variable load capable of changing the amplitude and phase of the reflection coefficient of the radio wave, a memory unit that stores information on the phase and amplitude of propagation path information in the radio wave propagation path between the radar device and the phantom unit, and information on the phase and amplitude of propagation path information in the target radio wave propagation path between the radar device and the measurement object, a control unit that sets the reflection coefficient of the variable load unit to a predetermined value, wherein the control unit adjusts the reflection coefficient of the variable load unit based on first propagation path information and second propagation path information so that the phase and amplitude constituting the first propagation path information in the radio wave propagation path between the antenna and the radar device approach the phase and amplitude constituting the second propagation path information in the radio wave propagation path between the radar device and the measurement object measured in advance, The radio wave propagation control system characterized by the above.

2. The phantom unit has a receiving function for receiving radio waves emitted from a transmitter constituting the radar device and acquiring propagation path information in the radio wave propagation path between the transmitter constituting the radar device and the antenna based on the received radio waves, The radio wave propagation control system according to claim 1, characterized by the above. Reconfiguration can be performed efficiently.

3. The phantom unit has a transmitting unit that emits radio waves, and the radio waves emitted from the antenna are received by a receiver constituting the radar device, and propagation path information in the radio wave propagation path between the antenna and the receiver constituting the radar device is acquired based on the received radio waves, The radio wave propagation control system according to claim 2, characterized by the above. Reconfiguration can be performed efficiently.

4. While radio waves are emitted from a transmitter constituting the radar device and received by a receiver constituting the radar device, the reflection coefficient of the variable load unit is changed one or more times to change the amplitude and / or phase of the radio waves received by the receiver constituting the radar device, and the first propagation path information is estimated based on the change in the amplitude and / or phase of the received radio waves, The radio wave propagation control system according to claim 1, characterized by the above. Reconfiguration can be performed efficiently.

5. The variable load includes a variable attenuator and a variable phase shifter. The radio wave propagation control system according to claim 1, characterized in that...

6. The variable load includes a hybrid coupler and a variable reactance. The hybrid coupler has a first port, a second port, a third port, and a fourth port. The antenna of the phantom unit is connected to the first port, a termination resistor equal to the reference impedance is connected to the second port, and independently controllable variable reactances are connected to the third and fourth ports, respectively. The radio wave propagation control system according to claim 1, characterized in that...

7. The variable load includes a hybrid coupler and a variable phase shifter. The hybrid coupler has a first port, a second port, a third port, and a fourth port. The antenna of the phantom unit is connected to the first port, a termination resistor equal to the reference impedance is connected to the second port, and the independently controllable variable phase shifters are connected to the third and fourth ports, respectively. The radio wave propagation control system according to claim 1, characterized in that...

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