A radar equivalent isotropic radiated power test method and system

Abstract

The present invention discloses a radar equivalent isotropic radiated power test method and system, which includes adding an auxiliary transceiver, a standard gain antenna, an auxiliary antenna and a reflector, adjusting the direction of the standard gain antenna when the standard gain antenna is connected to a radar transmitter, obtaining the maximum backscattered power received by the auxiliary transceiver; disconnecting the connection between the standard gain antenna and the radar transmitter, restoring the connection between the radar transmitter and the radar antenna, controlling the rotation of the radar servo motor, obtaining the maximum backscattered power received by the auxiliary transceiver; and finally calculating the equivalent isotropic radiated power EIRP according to the maximum backscattered power received by the auxiliary transceiver. The present invention has no special requirements for the test site, and the present invention can be applied to perform EIRP testing as long as the site meets the radar working requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of radar testing, and in particular relates to a radar equivalent isotropic radiated power testing method and system. Background Art

[0002] At present, the ability of radar transmitters to transmit signals is usually measured by the equivalent isotropic radiated power (EIRP). As an important indicator for measuring the performance of radar transmitters, the equivalent isotropic radiated power is also subject to restrictions in the laws and regulations of various countries. Therefore, how to accurately measure EIRP is particularly important.

[0003] The most common EIRP test method is direct measurement using the far-field method. This method arranges the position and orientation of the receiving antenna under far-field conditions. First, a transmitter with known power Pt and a standard gain Gs antenna is used to radiate the signal. The power Pr received by the receiving antenna can be used to infer the transmission loss L between the transmitting and receiving antennas. In the second step, the transmitter and antenna to be tested are arranged at the original standard gain antenna position and the transmission is turned on. The receiving antenna (the receiving antenna should be the same model, position and orientation as the receiving antenna in the first step) receives the power Prt. Then EIRP=Prt-Pr+Gs+Pt. This method has stable and reliable test results. However, this method requires the establishment of a synchronous receiving antenna in the far field. After the radar is set up, it is very expensive to establish the test site and platform. The general practice is to establish a dedicated far-field test site. After the radar leaves the factory, the EIRP index test cannot be performed. Summary of the invention

[0004] The purpose of the present invention is to provide a radar equivalent isotropic radiated power test method and system to solve the problem that the traditional EIRP index test cost is high and the EIRP index cannot be tested after the radar leaves the factory.

[0005] The present invention solves the above technical problems through the following technical solutions: a radar equivalent isotropic radiated power test method, in which an auxiliary transceiver, a standard gain antenna, an auxiliary antenna and a reflector are arranged at a radar installation site, the auxiliary transceiver is connected to the radar and the auxiliary antenna respectively; the reflector is suspended in the air and is used to backscatter the electromagnetic wave signal from the standard gain antenna to the auxiliary antenna or to backscatter the electromagnetic wave signal from the radar antenna to the auxiliary antenna; the test method comprises the following steps:

[0006] Step S1: connecting the standard gain antenna to one of the radar transmitters, and aligning the main beam of the standard gain antenna to the reflector;

[0007] Step S2: The radar transmitter connected to the standard gain antenna transmits a pulse electromagnetic wave signal, and the radar sends a synchronization pulse signal and a trigger signal to the auxiliary transceiver, so that the auxiliary transceiver is in a receiving working state and works synchronously with the radar;

[0008] Step S3: Adjust the direction of the standard gain antenna to maximize the backscatter power received by the auxiliary transceiver, and obtain and record the maximum backscatter power as P rs0 ;

[0009] Step S4: controlling the radar transmitter to stop transmitting, and restoring the radar transmitter to be connected to the radar antenna;

[0010] Step S5: Control the radar pulse emission and the radar servo motor to rotate so that the backscatter power received by the auxiliary transceiver is maximized, and obtain and record the maximum backscatter power as P t0 ;

[0011] Step S6: According to the maximum backscatter power received by the auxiliary transceiver P rs0 and P t0 Calculate the equivalent isotropic radiated power EIRP.

[0012] Furthermore, the position of the reflector satisfies the following conditions:

[0013] R ≥2 D 2 / λ

[0014] in, R is the distance between the reflector and the standard gain antenna or the distance between the reflector and the auxiliary antenna, D for d and l the sum of d The larger of the standard gain antenna aperture size, auxiliary antenna aperture size and radar antenna aperture size. l is the distance between the auxiliary antenna and the center of the radar antenna array, λ The operating wavelength of the radar.

[0015] Furthermore, the reflector is a metal ball, and the metal ball satisfies the following conditions:

[0016] 2 πr / λ ≥20,σ=2 πr

[0017] in,r is the radius of the metal sphere, σ is the reflection cross-sectional area of ​​the metal sphere, λ The operating wavelength of the radar.

[0018] Furthermore, the specific calculation formula of the equivalent isotropic radiated power is:

[0019] EIRP= P t0 - P rs0 + L s+ G s+ P 0

[0020] Where EIRP is the equivalent isotropic radiated power, L s is the line loss between the standard gain antenna and the radar transmitter, G s is the gain of the standard gain antenna, P 0 is the output power of the radar transmitter connected to a standard gain antenna.

[0021] Furthermore, in step S5, the maximum backscatter power P t0 The specific acquisition process is as follows:

[0022] Step S51: a positioning device is arranged on the reflector, the auxiliary transceiver is in a pulse transceiver working state, and the azimuth and elevation direction of the auxiliary antenna are adjusted so that the main beam of the auxiliary antenna is aligned with the reflector;

[0023] Step S52: acquiring geographical location information of the reflector and the radar, and calculating the azimuth and elevation angle of the line between the reflector and the radar antenna according to the geographical location information;

[0024] Step S53: adjusting the direction of the radar antenna array according to the azimuth angle and the elevation angle of the connecting line, so that the radar antenna array is aligned with the reflector;

[0025] Step S54: The radar transmits the electromagnetic wave signals of different frequencies and different beams in sequence while sending the synchronization pulse signal and the trigger signal to the auxiliary transceiver; assuming the frequency is f n The electromagnetic wave signal of the measured beam numbered m is b m ;

[0026] The auxiliary transceiver receives, measures and records the echo strength of the distance bin where the signal reflected by the reflector is located P tnm, and the angle between the normal line of the radar antenna array and the line connected in step S52, and transmitting the echo intensity to the radar; wherein P tnm Indicates the frequency f n , beam is b m The echo intensity corresponding to the electromagnetic wave signal;

[0027] Step S55: maintaining the working state of step S54, taking the line between the reflector and the radar antenna as the center, controlling the radar servo motor to rotate and traverse the azimuth and elevation angles required for testing, and recording the electromagnetic wave signal frequency, beam number and echo intensity of the electromagnetic wave signal corresponding to different azimuth and elevation angles;

[0028] Step S56: Determine the maximum backscattering power based on the electromagnetic wave signal frequency, beam number and echo intensity corresponding to the different azimuth and elevation angles obtained in step S55. P t0 .

[0029] Furthermore, the maximum electromagnetic wave power received by the auxiliary antenna is greater than the sum of the receiving sensitivity of the auxiliary transceiver, the absolute value of the maximum sidelobe suppression of the radar antenna, and the system loss between the auxiliary antenna and the auxiliary transceiver.

[0030] Furthermore, the calculation formula of the electromagnetic wave power received by the auxiliary antenna is:

[0031] P r = P t * G t * G r *σ*λ 2 / (4π) 3 * R 4

[0032] in, P r is the electromagnetic wave power received by the auxiliary antenna, P t is the radar transmitting power, G t is the transmission gain of the radar antenna, G r is the receiving gain of the auxiliary antenna, R is the distance between the reflector and the auxiliary antenna, σ is the reflection cross-sectional area of ​​the reflector, λ The operating wavelength of the radar.

[0033] The present invention also provides a radar equivalent isotropic radiated power test system, comprising a radar, an auxiliary transceiver, a standard gain antenna, an auxiliary antenna and a reflector; the auxiliary transceiver is connected to the radar and the auxiliary antenna respectively, and the standard gain antenna is connected to one of the radar transmitters; the main beam of the standard gain antenna is aligned with the reflector; the reflector is suspended in the air and is used to backscatter the electromagnetic wave signal from the standard gain antenna to the auxiliary antenna or backscatter the electromagnetic wave signal from the radar antenna to the auxiliary antenna;

[0034] The radar controller is used to control the radar transmitter connected to the standard gain antenna to transmit a pulse electromagnetic wave signal, and at the same time send a synchronization pulse signal and a trigger signal to the auxiliary transceiver, so that the auxiliary transceiver is in a receiving working state and works synchronously with the radar, and after adjusting the direction of the standard gain antenna so that the backscatter power received by the auxiliary transceiver is the maximum, obtain and record the maximum backscatter power as P rs0 ; used to control the radar pulse emission when the radar transmitter is connected to the radar antenna, control the rotation of the radar servo motor, so that the backscatter power received by the auxiliary transceiver is maximized, and obtain and record the maximum backscatter power as P t0 ; and for receiving a maximum backscatter power according to the auxiliary transceiver P rs0 and P t0 Calculate the equivalent isotropic radiated power EIRP.

[0035] Furthermore, the specific calculation formula of the equivalent isotropic radiated power is:

[0036] EIRP= P t0 - P rs0 + L s+ G s+ P 0

[0037] Where EIRP is the equivalent isotropic radiated power, L s is the line loss between the standard gain antenna and the radar transmitter, G s is the gain of the standard gain antenna, P 0 is the output power of the radar transmitter connected to a standard gain antenna.

[0038] Beneficial Effects

[0039] Compared with the prior art, the advantages of the present invention are:

[0040] The radar equivalent isotropic radiated power test method and system provided by the present invention have no special requirements for the test site, and the present invention can be applied to perform EIRP test as long as the site meets the radar working requirements; the radar itself is used to build the test platform to the maximum extent, and only an auxiliary transceiver, an auxiliary antenna and a standard gain antenna are required to be additionally added, and these added devices can be quickly disassembled and reused; the auxiliary transceiver and the radar system can be used to work together to perform simultaneous multi-frequency point and multi-beam tests, and the test efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 1 is a schematic diagram of the structure of a radar equivalent isotropic radiated power test system according to an embodiment of the present invention;

[0043] Figure 2 is the maximum echo intensity or maximum backscatter power in the embodiment of the present invention P t0 Schematic diagram of the system structure during testing. DETAILED DESCRIPTION

[0044] The following is a clear and complete description of the technical solutions in the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0046] The radar equivalent isotropic radiated power test method provided in the embodiment of the present invention mainly utilizes the radar system itself, plus an auxiliary antenna, a standard gain antenna, an auxiliary transceiver and a reflector suspended in the air to achieve the equivalent isotropic radiated power test. The specific structural diagram is shown in FIG. Figure 1As shown, the RF common port of the auxiliary transceiver is connected to the feed port of the auxiliary antenna, and the analog intermediate frequency / digital intermediate frequency signal, synchronization signal and trigger signal of the auxiliary transceiver are connected to the radar; the reflector is suspended in the air and is used to backscatter the electromagnetic wave signal from the standard gain antenna to the auxiliary antenna or backscatter (i.e., reflect or refract) the electromagnetic wave signal from the radar antenna to the auxiliary antenna, and a positioning device is provided on the reflector.

[0047] The radar is the radar to be tested, which can be a single-beam or multi-beam radar that can only transmit but not receive or can both transmit and receive. The radar is equipped with a high-precision positioning device; the azimuth and / or elevation angle of the radar antenna can be rotated under the action of the radar servo motor; while sending electromagnetic wave signals, the radar sends synchronization pulse signals and other control signals to the auxiliary transceiver to achieve synchronous and coordinated work of the two transceivers.

[0048] The reflector backscatters the electromagnetic wave signal from the auxiliary antenna to the radar antenna, or backscatters the electromagnetic wave signal from the radar antenna to the auxiliary antenna, or backscatters the electromagnetic wave signal from the standard gain antenna to the auxiliary antenna; the reflector is equipped with a high-precision positioning device.

[0049] The auxiliary antenna is used to transmit electromagnetic wave signals (such as Figure 2 The electromagnetic wave signal is transmitted to the radar antenna after passing through the reflector, or the electromagnetic wave signal emitted by the radar antenna and passing through the reflector is received (as shown by the solid line). Figure 2 dotted line), or receive electromagnetic wave signals emitted by a standard gain antenna and passing through a reflector (such as Figure 1 dotted line).

[0050] The auxiliary transceiver can synchronously generate a transmission excitation signal and transmit it to the auxiliary antenna for transmission when testing the radar receiving beam pattern according to the signal or instruction sent by the radar; when testing the radar transmitting beam pattern, it can synchronously receive and process the signal from the auxiliary antenna that is transmitted by the radar and passed through the reflector. The auxiliary transceiver can process the electromagnetic wave signal received by the auxiliary antenna and transmit it to the radar, and the radar can obtain the reflected signal strength received by the auxiliary antenna; when testing the equivalent isotropic radiated power, it can synchronously receive and process the signal from the auxiliary antenna that is transmitted by the standard gain antenna and reflected by the reflector. The auxiliary transceiver can process the electromagnetic wave signal received by the auxiliary antenna and transmit it to the radar.

[0051] In a specific embodiment of the present invention, the auxiliary transceiver is an analog transceiver or a digital transceiver. The analog transceiver processes the electromagnetic wave signal by low-noise amplification, frequency conversion and filtering, and the digital transceiver processes the electromagnetic wave signal by low-noise amplification, frequency conversion and filtering, analog-to-digital conversion, and other processes.

[0052] based on Figure 1The structure shown in FIG. 1 is a radar equivalent isotropic radiated power test method comprising the following steps:

[0053] Step S1: Use a coaxial cable with a line loss of Ls to connect the standard gain antenna to any radar channel (i.e. any radar transmitter), where the transmission power of the channel is P 0 , calculate the relative direction according to the reflector position coordinates and the radar position coordinates, and align the main beam of the standard gain antenna to the reflector.

[0054] The reflector is suspended in the air, and its suspension position meets the following conditions:

[0055] R ≥2 D 2 / λ (1)

[0056] in, R is the distance between the reflector and the standard gain antenna or the distance between the reflector and the auxiliary antenna, D for d and l The sum of d The larger of the standard gain antenna aperture size, auxiliary antenna aperture size and radar antenna aperture size. l is the distance between the auxiliary antenna and the center of the radar antenna array, λ The wavelength is the radar working wavelength. The reflector keeps the same position and reflection performance during the test.

[0057] In a specific embodiment of the present invention, the scattering property of the reflector is in the optical region, for example, the reflector is a metal sphere, and the metal sphere satisfies the following conditions:

[0058] 2 πr / λ ≥20 (2)

[0059] σ=2 πr (3)

[0060] in, r is the radius of the metal sphere, σ is the reflection cross-sectional area of ​​the metal sphere. If the above relationship is satisfied, σ is insensitive to the radar operating wavelength.

[0061] Step S2: The radar controller controls the radar transmitter connected to the standard gain antenna to transmit a pulse electromagnetic wave signal, and other radar transmitters or transmission channels are silent (not transmitting signals). At the same time, the radar controller sends a synchronization pulse signal and a trigger signal to the auxiliary transceiver, so that the auxiliary transceiver is in a receiving working state and works synchronously with the radar.

[0062] The synchronization pulse signal enables the radar and the auxiliary transceiver to work synchronously and cooperatively, and the trigger signal triggers the auxiliary transceiver to enter the receiving working state.

[0063] Step S3: Adjust the direction of the standard gain antenna to maximize the backscatter power received by the auxiliary transceiver. The radar controller obtains and records the maximum backscatter power as P rs0 .

[0064] Step S4: Control the radar transmitter to stop transmitting, disconnect the standard gain antenna from the radar transmitter, and restore the radar transmitter to be connected to the feed port of the radar antenna.

[0065] Step S5: The radar controller controls the radar pulse emission and the radar servo motor to rotate so that the backscatter power received by the auxiliary transceiver is maximized, and the maximum backscatter power is obtained and recorded as P t0 .

[0066] Step S6: Based on the maximum backscatter power received by the auxiliary transceiver P rs0 and P t0 Calculate the equivalent isotropic radiated power EIRP. The specific calculation formula is:

[0067] EIRP nm = P t0nm - P rs0 + L s+ G s+ P 0 (4)

[0068] Among them, EIRP nm is the equivalent isotropic radiated power, P t0nm The frequency is f when the transmission pattern is tested. m , beam b n The maximum echo strength or maximum backscatter power received by the auxiliary transceiver, L s is the line loss between the standard gain antenna and the radar transmitter, G s is the gain of the standard gain antenna, P 0 is the output power of the radar transmitter connected to a standard gain antenna.

[0069] Disconnect the standard gain antenna from the radar transmitter, set a positioning device on the reflector, and keep other structures and connection relationships unchanged, such as Figure 2As shown, the auxiliary transceiver is connected to the radar and the auxiliary antenna respectively, and the reflector is suspended in the air and is used to backscatter (i.e. reflect or refract) the electromagnetic wave signal from the auxiliary antenna or the radar antenna to the radar antenna or the auxiliary antenna. Figure 2 The structure is used to obtain the maximum echo intensity or maximum backscatter power during the radar antenna transmission pattern test. P t0nm , maximum echo intensity or maximum backscatter power P t0nm The specific acquisition process is as follows:

[0070] Step S51: suspend the reflector in the air, and the suspending position of the reflector satisfies the condition shown in formula (1).

[0071] The reflector maintains a constant position and constant reflective properties during the test.

[0072] In a specific embodiment of the present invention, the scattering characteristics of the reflector are in the optical region, for example, the reflector is a metal sphere, and the metal sphere satisfies the conditions shown in equations (2) and (3).

[0073] Step S52: The auxiliary transceiver is in a pulse transceiver working state, and the azimuth and elevation directions of the auxiliary antenna are adjusted so that the main beam of the auxiliary antenna is aimed at the reflector. At this time, the backscattered echo intensity received by the auxiliary transceiver is the strongest.

[0074] When the auxiliary antenna main beam is aimed at the center of the reflector, the backscattered power received by the auxiliary transceiver is the strongest, avoiding the influence of auxiliary antenna side lobes, ground objects and other clutter, and improving the test accuracy. At this time, the auxiliary antenna main lobe is aimed at the reflector, and the subsequent steps keep the auxiliary antenna direction and position unchanged.

[0075] The auxiliary antenna aperture size should make its main beam width larger than the angular resolution of the pattern. For example, the auxiliary antenna aperture size should make its main beam width larger than 10 times (or larger) the angular resolution of the pattern. When the gain error allowed by the pattern is, for example, 0.3dB, the corresponding beam width should be limited to 0.3dB beam width.

[0076] The maximum electromagnetic wave power received by the auxiliary antenna (when both the radar antenna and the auxiliary antenna are aimed at the reflector) is greater than the sum of the receiving sensitivity of the auxiliary transceiver, the absolute value of the maximum sidelobe suppression of the radar antenna, and the system loss between the auxiliary antenna and the auxiliary transceiver. When the power received by the auxiliary transceiver is less than the sensitivity, the received power cannot be effectively measured; the reason why the absolute value of the maximum sidelobe suppression of the antenna is added is that the power received when the reflector is aimed at different angles is actually the power received when the main beam is aimed at the reflector minus the absolute value of the sidelobe suppression of the antenna at the corresponding angle.

[0077] In a specific implementation of the present invention, the calculation formula for the electromagnetic wave power received by the auxiliary antenna is:

[0078] P r = P t * G t * G r *σ*λ 2 / (4π) 3 * R 4 (5)

[0079] in, P r is the electromagnetic wave power received by the auxiliary antenna, P t is the radar transmitting power, G t is the transmission gain of the radar antenna, G r is the receiving gain of the auxiliary antenna, R is the distance between the reflector and the radar antenna, σ is the reflection cross-sectional area of ​​the reflector, λ The operating wavelength of the radar.

[0080] Step S53: Obtain the geographical location information of the reflector and the radar, and calculate the azimuth and elevation angle of the line between the reflector and the radar antenna according to the geographical location information.

[0081] The radar and the reflector are both equipped with positioning devices, through which the latitude, longitude and altitude information of the reflector and the latitude, longitude and altitude information of the radar can be obtained. According to the latitude, longitude and altitude information of the reflector and the latitude, longitude and altitude information of the radar, the azimuth angle φ of the line connecting the reflector and the radar antenna can be calculated. 0 and the pitch angle θ 0 .

[0082] Step S54: adjusting the direction of the radar antenna array according to the azimuth angle and elevation angle of the connecting line so that the radar antenna array is aligned with the reflector.

[0083] Step S55: The radar transmits electromagnetic wave signals of different frequencies and different beams in sequence, and at the same time sends the synchronization pulse signal and the trigger signal to the auxiliary transceiver to achieve synchronous and coordinated operation of the two; the electromagnetic wave signal is transmitted to the reflector, and then transmitted back to the auxiliary antenna after passing through the reflector, and the auxiliary transceiver receives, measures and records the echo intensity of the distance library where the signal reflected by the reflector is located. P tnm(i.e., the electromagnetic wave power corresponding to the distance library), and the angle between the normal line of the radar antenna array and the line connected in step S43, and transmit the echo intensity to the radar.

[0084] The radar transmits at the following frequencies: f n (n=1,2,3,…) pulse electromagnetic wave signals, each frequency of which can independently set the required test beam b m (m=1,2,3,…); P tnm Indicates the nth frequency f n , the mth beam b m The echo intensity corresponding to the electromagnetic wave signal.

[0085] Step S56: Keep the working state of step S55, control the radar servo motor to rotate and traverse the azimuth angle required for testing (-φ tmax , +φ tmax ) and pitch angle (-θ tmax , +θ tmax ), record the electromagnetic wave signal frequency, beam number and echo intensity corresponding to different azimuth and elevation angles, that is, record ( f n , b m , P tnm ,φ t ,θ t ).

[0086] Step S57: Based on step S56, the electromagnetic wave signal frequency, beam number and echo strength corresponding to the different azimuth and elevation angles to be tested can be obtained, and the maximum echo strength or maximum backscatter power received by the auxiliary transceiver can be determined. P t0nm .

[0087] Maximum echo strength P t0 The corresponding azimuth φ t0 and the pitch angle θ t0 That is, the transmitting beam is pointed. Use MATLAB or other drawing software to draw the beam b m ,frequency f n The test results ( P tnm ,φ t ,θ t) is plotted, and the operating frequency is f n , b m The beam transmission pattern is to draw the normalized three-dimensional radiation pattern of the radar antenna transmission beam.

[0088] In a specific embodiment of the present invention, based on Figure 2 The structure is used to obtain the maximum echo intensity or the maximum backscatter power during the simultaneous testing of the radar antenna transmission pattern and the receiving pattern. P t0nm , maximum echo intensity or maximum backscatter power P t0nm The specific acquisition process is as follows:

[0089] Step S61: suspend the reflector in the air, and the suspending position of the reflector satisfies the condition shown in formula (1).

[0090] The reflector maintains a constant position and constant reflective properties during the test.

[0091] In a specific embodiment of the present invention, the scattering characteristics of the reflector are in the optical region, for example, the reflector is a metal sphere, and the metal sphere satisfies the conditions shown in equations (2) and (3).

[0092] Step S62: The auxiliary transceiver is in a pulse transceiver working state, and the azimuth and elevation directions of the auxiliary antenna are adjusted so that the main beam of the auxiliary antenna is aimed at the reflector.

[0093] When the auxiliary antenna main beam is aimed at the center of the reflector, the backscattered echo intensity received by the auxiliary transceiver is the strongest, avoiding the influence of auxiliary antenna side lobes, ground objects and other clutter, and improving the test accuracy. At this time, the auxiliary antenna main lobe is aimed at the reflector, and the subsequent steps keep the auxiliary antenna direction and position unchanged.

[0094] During transmission calibration, the maximum electromagnetic wave power received by the auxiliary antenna (when both the radar antenna and the auxiliary antenna are aimed at the reflector) is greater than the sum of the auxiliary transceiver receiving sensitivity, the absolute value of the maximum sidelobe suppression of the radar antenna, and the system loss between the auxiliary antenna and the auxiliary transceiver.

[0095] In a specific implementation of the present invention, the calculation formula for the electromagnetic wave power received by the auxiliary antenna is shown in formula (5).

[0096] During receiving calibration, the maximum electromagnetic wave power received by the radar antenna (when both the radar antenna and the auxiliary antenna are aimed at the reflector) is greater than the sum of the radar sensitivity, the absolute value of the maximum sidelobe suppression of the radar antenna, and the system loss between the radar antenna and the auxiliary transceiver.

[0097] In a specific implementation of the present invention, the calculation formula for the electromagnetic wave power received by the radar antenna is:

[0098] P r2 = P t2 * G t2 * G r2 *σ*λ 2 / (4π) 3 * R 4

[0099] in, P r2 is the electromagnetic wave power received by the radar antenna, P t2 To assist the transceiver transmit power, G t2 is the transmission gain of the auxiliary antenna, G r2 is the receiving gain of the radar antenna, R is the distance between the reflector and the radar antenna, σ is the reflection cross-sectional area of ​​the reflector, λ The operating wavelength of the radar.

[0100] Step S63: Obtain the geographical location information of the reflector and the radar, and calculate the azimuth and elevation angle of the line between the reflector and the radar antenna according to the geographical location information.

[0101] The radar and the reflector are both equipped with positioning devices, through which the latitude, longitude and altitude information of the reflector and the latitude, longitude and altitude information of the radar can be obtained. According to the latitude, longitude and altitude information of the reflector and the latitude, longitude and altitude information of the radar, the azimuth angle φ of the line connecting the reflector and the radar antenna can be calculated. 0 and the pitch angle θ 0 .

[0102] Step S64: adjusting the direction of the radar antenna array according to the azimuth angle and elevation angle of the connecting line so that the radar antenna array is aligned with the reflector.

[0103] Step S65: The radar sends a synchronization pulse signal and a trigger signal to the auxiliary transceiver, so that the radar and the auxiliary transceiver work synchronously and cooperatively; the radar and the auxiliary transceiver alternately transmit and receive electromagnetic wave signals of different frequencies and different beams, and the auxiliary transceiver sequentially receives, measures and records the echo intensity of the distance bin where the signal transmitted by the radar and reflected by the reflector is located, and the radar sequentially receives, measures and records the echo intensity of the distance bin where the signal transmitted by the auxiliary transceiver and reflected by the reflector is located.

[0104] In a specific embodiment of the present invention, the radar and the auxiliary transceiver alternately transmit and receive electromagnetic wave signals of different frequencies and different beams, which means that: the radar transmission frequency is f 1 , beam b 1 The electromagnetic wave signal is backscattered to the auxiliary antenna after passing through the reflector, and the auxiliary transceiver receives, measures and records the echo intensity of the distance library where the signal is located. P t11 ; The auxiliary transceiver transmission frequency is f 1 , beam b 1 The electromagnetic wave signal is backscattered to the radar antenna after passing through the reflector. The radar receives, measures and records the echo intensity of the distance library where the signal is located. P r11 The radar transmission frequency is f 2 , beam b 2 The electromagnetic wave signal is backscattered to the auxiliary antenna after passing through the reflector, and the auxiliary transceiver receives, measures and records the echo intensity of the distance library where the signal is located. P t22 ; The auxiliary transceiver transmission frequency is f 2 , beam is b 2 The electromagnetic wave signal is backscattered to the radar antenna after passing through the reflector. The radar receives, measures and records the echo intensity of the distance library where the signal is located. P r22 The radar transmission frequency is f 3 , beam is b 3 The electromagnetic wave signal is backscattered to the auxiliary antenna after passing through the reflector, and the auxiliary transceiver receives, measures and records the echo intensity of the distance library where the signal is located. P t33 ; The auxiliary transceiver transmission frequency is f 3 , beam b 3 The electromagnetic wave signal is backscattered to the radar antenna after passing through the reflector. The radar receives, measures and records the echo intensity of the distance library where the signal is located. P r3 In this way, electromagnetic wave signals are transmitted alternately and sequentially to achieve simultaneous testing of the transmission pattern and the reception pattern.

[0105] Step S66: Keep the working state of step S65, control the radar servo motor to rotate and traverse the azimuth angle required for testing (-φ max , +φ max ) and pitch angle (-θ max , +θ max ), record the electromagnetic wave signal frequency, beam number and echo intensity corresponding to different azimuth and elevation angles, that is, record ( f n , b m , P tnm , P rnm , φ, θ).

[0106] Step S67: Based on step S66, the electromagnetic wave signal frequency, the electromagnetic wave signal beam and the echo strength corresponding to the different azimuth and elevation angles to be tested can be obtained, and the maximum echo strength received by the auxiliary transceiver can be determined. P t0 The corresponding azimuth φ t0 and the pitch angle θ t0 , and the maximum echo intensity received by the radar P r0 The corresponding azimuth φ r0 and the pitch angle θ r0 .

[0107] According to the echo strength received by the auxiliary transceiver P tnm And the corresponding relationship between the azimuth angle φ and the pitch angle θ is used to draw the transmission direction diagram; according to the echo intensity received by the radar P rnm The receiving radiation pattern is drawn based on the correspondence between the azimuth angle φ and the elevation angle θ.

[0108] What is disclosed above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A radar equivalent isotropic radiated power test method, characterized in that: An auxiliary transceiver, a standard gain antenna, an auxiliary antenna and a reflector are provided at a radar installation site, wherein the auxiliary transceiver is connected to the radar and the auxiliary antenna respectively; the reflector is suspended in the air and is used to backscatter the electromagnetic wave signal from the standard gain antenna to the auxiliary antenna or to backscatter the electromagnetic wave signal from the radar antenna to the auxiliary antenna; the testing method comprises the following steps: Step S1: connecting the standard gain antenna to one of the radar transmitters, and aligning the main beam of the standard gain antenna to the reflector; Step S2: The radar transmitter connected to the standard gain antenna transmits a pulse electromagnetic wave signal, and the radar sends a synchronization pulse signal and a trigger signal to the auxiliary transceiver, so that the auxiliary transceiver is in a receiving working state and works synchronously with the radar; Step S3: Adjust the direction of the standard gain antenna to maximize the backscatter power received by the auxiliary transceiver, and obtain and record the maximum backscatter power as P rs0 ; Step S4: controlling the radar transmitter to stop transmitting, and restoring the radar transmitter to be connected to the radar antenna; Step S5: Control the radar pulse emission and the radar servo motor to rotate so that the backscatter power received by the auxiliary transceiver is maximized, and obtain and record the maximum backscatter power as P t0 ; Step S6: according to the maximum backscatter power received by the auxiliary transceiver P rs0 and P t0 Calculate the equivalent isotropic radiated power EIRP.

2. The radar equivalent isotropic radiated power test method according to claim 1, characterized in that: The position of the reflector satisfies the following conditions: R ≥2 D 2 / λ in, R is the distance between the reflector and the standard gain antenna or the distance between the reflector and the auxiliary antenna, D for d and l The sum of d The larger of the standard gain antenna aperture size, auxiliary antenna aperture size and radar antenna aperture size. l is the distance between the auxiliary antenna and the center of the radar antenna array, λ The operating wavelength of the radar.

3. The radar equivalent isotropic radiated power test method according to claim 1 or 2, characterized in that: The reflector is a metal ball, and the metal ball meets the following conditions: 2 πr / λ ≥20,σ=2 πr in, r is the radius of the metal sphere, σ is the reflection cross-sectional area of ​​the metal sphere, λ The operating wavelength of the radar.

4. The radar equivalent isotropic radiated power test method according to claim 1, characterized in that: The specific calculation formula of the equivalent isotropic radiated power is: EIRP= P t0 - P rs0 + L s+ G s+ P 0 Where EIRP is the equivalent isotropic radiated power, L s is the line loss between the standard gain antenna and the radar transmitter, G s is the gain of the standard gain antenna, P 0 is the output power of the radar transmitter connected to a standard gain antenna.

5. The radar equivalent isotropic radiated power test method according to claim 1, characterized in that: In step S5, the maximum backscattered power P t0 The specific acquisition process is as follows: Step S51: a positioning device is arranged on the reflector, the auxiliary transceiver is in a pulse transceiver working state, and the azimuth and elevation direction of the auxiliary antenna are adjusted so that the main beam of the auxiliary antenna is aligned with the reflector; Step S52: acquiring geographical location information of the reflector and the radar, and calculating the azimuth and elevation angle of the line between the reflector and the radar antenna according to the geographical location information; Step S53: adjusting the direction of the radar antenna array according to the azimuth angle and the elevation angle of the connecting line, so that the radar antenna array is aligned with the reflector; Step S54: The radar transmits the electromagnetic wave signals of different frequencies and different beams in sequence while sending the synchronization pulse signal and the trigger signal to the auxiliary transceiver; assuming the frequency is f n The electromagnetic wave signal of the measured beam numbered m is b m ; The auxiliary transceiver receives, measures and records the echo strength of the distance bin where the signal reflected by the reflector is located P tnm , and the angle between the normal line of the radar antenna array and the line connected in step S52, and transmitting the echo intensity to the radar; wherein P tnm Indicates the frequency f n , beam is b m The echo intensity corresponding to the electromagnetic wave signal; Step S55: maintaining the working state of step S54, taking the line between the reflector and the radar antenna as the center, controlling the radar servo motor to rotate and traverse the azimuth and elevation angles required for testing, and recording the electromagnetic wave signal frequency, beam number and echo intensity of the electromagnetic wave signal corresponding to different azimuth and elevation angles; Step S56: Determine the maximum backscattering power based on the electromagnetic wave signal frequency, beam number and echo intensity corresponding to the different azimuth and elevation angles obtained in step S55. P t0 .

6. The radar equivalent isotropic radiated power test method according to claim 5, characterized in that: The maximum electromagnetic wave power received by the auxiliary antenna is greater than the sum of the receiving sensitivity of the auxiliary transceiver, the absolute value of the maximum sidelobe suppression of the radar antenna, and the system loss between the auxiliary antenna and the auxiliary transceiver.

7. The radar equivalent isotropic radiated power test method according to claim 5, characterized in that: The calculation formula of the electromagnetic wave power received by the auxiliary antenna is: P r = P t * G t * G r *s*l 2 / (4π) 3 * R 4 in, P r is the electromagnetic wave power received by the auxiliary antenna, P t is the radar transmitting power, G t is the transmission gain of the radar antenna, G r is the receiving gain of the auxiliary antenna, R is the distance between the reflector and the auxiliary antenna, σ is the reflection cross-sectional area of ​​the reflector, λ The operating wavelength of the radar.

8. A radar equivalent isotropic radiated power test system, characterized in that: It includes a radar, an auxiliary transceiver, a standard gain antenna, an auxiliary antenna and a reflector; the auxiliary transceiver is connected to the radar and the auxiliary antenna respectively, the standard gain antenna is connected to one of the radar transmitters; the main beam of the standard gain antenna is aligned with the reflector; The reflector is suspended in the air and is used to backscatter the electromagnetic wave signal from the standard gain antenna to the auxiliary antenna or to backscatter the electromagnetic wave signal from the radar antenna to the auxiliary antenna; The radar controller is used to control the radar transmitter connected to the standard gain antenna to transmit a pulse electromagnetic wave signal, and at the same time send a synchronization pulse signal and a trigger signal to the auxiliary transceiver, so that the auxiliary transceiver is in a receiving working state and works synchronously with the radar, and after adjusting the direction of the standard gain antenna so that the backscatter power received by the auxiliary transceiver is the maximum, obtain and record the maximum backscatter power as P rs0 ; used to control the radar pulse emission when the radar transmitter is connected to the radar antenna, control the rotation of the radar servo motor, so that the backscatter power received by the auxiliary transceiver is maximized, and obtain and record the maximum backscatter power as P t0 ; and for receiving a maximum backscatter power according to the auxiliary transceiver P rs0 and P t0 Calculate the equivalent isotropic radiated power EIRP.

9. The radar equivalent isotropic radiated power test system according to claim 8, characterized in that: The specific calculation formula of the equivalent isotropic radiated power is: EIRP= P t0 - P rs0 + L s+ G s+ P 0 Where EIRP is the equivalent isotropic radiated power, L s is the line loss between the standard gain antenna and the radar transmitter, G s is the gain of the standard gain antenna, P 0 is the output power of the radar transmitter connected to a standard gain antenna.

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