Airborne active phased array meteorological radar measuring tool
By designing an airborne active phased array weather radar measurement fixture, utilizing the transmission of radio frequency signals in a confined space and precise calibration methods, the problem of radar system measurement and calibration under high and low temperature environments was solved, achieving accurate sensitivity, transmission power, and amplitude and phase calibration.
Patent Information
- Application Number
- CN202511376227.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2025-12-12
AI Technical Summary
Existing technologies cannot directly measure the sensitivity and transmit power of active phased array radar systems in high and low temperature environments, and field calibration is difficult, especially in harsh electromagnetic environments where accurate antenna array amplitude and phase calibration is difficult.
An airborne active phased array weather radar measurement fixture was designed, including a measurement antenna array, a metal grid, and a power divider. It transmits radio frequency signals through a closed space and uses a signal source, power meter, and vector network analyzer to perform sensitivity, transmit power, and amplitude and phase calibration, thereby reducing external electromagnetic interference.
It enables precise measurement and calibration of radar systems in high and low temperature environments, reduces reliance on complex equipment and anechoic chamber environments, and improves measurement accuracy and anti-interference capabilities.
Smart Images
Figure CN121114944A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of airborne active phased array weather radar, and particularly to a kind of airborne active phased array weather radar measuring tool. BACKGROUND
[0002] In the field of civil aviation, there is a very high requirement for the test coverage of radar system indicators. The radar system receiving sensitivity and the radar system transmitting power are the parameters that need to be obtained in the minimum performance test of civil aircraft weather radar, and are the key indicators of the radar. The measurement of radar system sensitivity needs to input a power-determined radio frequency signal to the radar, and the measurement of radar system transmitting power needs to directly measure the transmitting power of the radar array. On the active phased array radar, due to the distributed front-end transceiver components, it is not possible to provide a centralized radio frequency test port, which results in the inability to directly measure the instrument for measurement. The above key parameters can be indirectly measured at room temperature, but due to the dependence of the measurement on the darkroom environment and the space, it is not possible to measure in high and low temperature environments, and the space loss from the signal source to the radar antenna receiving end is dependent on the estimation, and there is a certain error in the indirect measurement result. Therefore, the measurement tool and method capable of directly measuring the active phased array radar system sensitivity and transmitting power in high and low temperature environments are proposed, which has a very important significance for meeting the test coverage requirement of civil aircraft active phased array weather radar.
[0003] In active phased array radar systems, the initial amplitude and phase consistency of each array element has a key influence on beam forming and main lobe pointing accuracy. An active phased array needs to be calibrated for amplitude and phase before leaving the factory, and the array surface amplitude and phase characteristics also need to be calibrated in the field during service. Some phased arrays of certain architecture can be calibrated by removing the antenna elements to calibrate each channel, which is a cumbersome process and not suitable for phased arrays of all architectures. Currently, the external calibration scheme in specific environments and equipment is quite complete, but there are many problems in the external calibration of phased arrays in the field. The commonly used calibration methods are near-field scanning method, mutual method, and rotating electric vector method: (1) The near-field scanning method needs to scan the array surface scanning plane with a scanning frame and a probe to obtain discrete near-field measurement results, and then the array excitation and far-field results are obtained by fast Fourier transform. This method requires complex equipment and suitable environment, which is difficult to implement in the field; (2) The mutual method does not require complex calibration equipment, but requires that the element topology structure meet the symmetric condition or the mutual coefficient be known, which has great constraints on the antenna topology structure design and directional diagram. (3) The rotating electric vector method needs to change the phase of each channel one by one, and calculate the initial phase of each element by measuring the data one by one, which requires a far-field measurement environment and a large amount of measurement and calculation time, and the calibration efficiency is extremely low, and it is not suitable for large-scale arrays. On the other hand, with the development of wireless communication technology, the electromagnetic environment is becoming more and more severe, and it is difficult to have a darkroom environment for field measurement, and electromagnetic interference is also a major problem to ensure the accuracy of field calibration. SUMMARY
[0004] Therefore, the present application provides an airborne active phased array weather radar measurement tool, which solves the problems in the prior art and improves the measurement accuracy of the airborne active phased array weather radar.
[0005] The airborne active phased array weather radar measurement tool provided by the present application adopts the following technical solution: An airborne active phased array weather radar measurement tool, comprising: a measurement antenna array having a plurality of spaced antenna elements, the topology structure of the measurement antenna array being consistent with that of a to-be-measured radar antenna array; a metal grid net fixedly connected to one side of the measurement antenna array and to the other side of the to-be-measured radar antenna array, the antenna elements on the to-be-measured radar antenna array and the measurement antenna array each corresponding to a grid of the metal grid net, the center of each antenna element on the to-be-measured radar antenna array and the measurement antenna array coinciding with the center of the corresponding grid, and the grid being used to isolate the transmission channels of adjacent antenna elements; the output end of the power divider is electrically connected to the antenna elements of the measurement antenna array; and A test instrument is electrically connected to the input end of the power divider, and the test instrument is configured to send a radio frequency signal to the radar antenna to be tested through the power divider and the measurement antenna array, or the test instrument is configured to receive a radio frequency signal from the radar antenna to be tested through the power divider and the measurement antenna array.
[0006] Optionally, a plurality of metal through holes are arranged around each antenna unit of the measurement antenna array, the metal through holes are connected to the ground of the measurement antenna array, and the metal through holes are in contact with the metal grid.
[0007] Optionally, the metal through holes are arranged along the metal structure of the metal grid.
[0008] Optionally, the transmission structure of the radio frequency signal transmission channel formed by the two antenna units corresponding to a single grid of the metal grid and the grid is antenna-waveguide-antenna.
[0009] Optionally, the test instrument is a signal source, and the measurement tool is configured to perform sensitivity measurement on the radar to be tested. The TR component of the radar to be tested is kept in a receiving state by the upper computer, a signal is injected into the input port of the power division network of the measurement calibration tool by the signal source, the signal passes through the power divider of the measurement tool and the measurement antenna array, and then passes through the transmission channel, the antenna of the antenna array of the radar to be tested receives the signal, the transceiver AD of the radar to be tested samples, and the signal amplitude and noise amplitude are obtained after being processed by the processor of the radar to be tested and are sent to the upper computer. The signal power injected by the signal source is gradually reduced until the required signal-to-noise ratio threshold is reached, and the signal source input power P at this time is recorded. in , The system sensitivity is P in minus the difference loss of the transmission line, the difference loss of the power divider, and the transmission difference loss between the measurement antenna array and the antenna array of the radar to be tested.
[0010] Optionally, the test instrument is a power meter, and the measurement tool is configured to perform transmit power measurement on the radar to be tested. The TR component of the radar to be tested is kept in a transmitting state by the upper computer, the radar to be tested transmits a radio frequency signal, and the radio frequency signal is transmitted to the power meter in sequence through the transmission channel, the measurement antenna array, and the power divider of the measurement tool, and the output power value P of the power meter is measured. out ; The transmit power of the airborne active phased array weather radar is the output power value P outj plus the difference loss of the transmission line, the difference loss of the power divider, and the transmission difference loss between the measurement antenna array and the antenna array of the radar to be tested.
[0011] Optionally, the test instrument is a vector network analyzer, and two channels of the vector network analyzer are connected to the power divider set port of the antenna under test and the measurement calibration tool respectively, and are used for transmitting amplitude and phase calibration and receiving amplitude and phase calibration of the radar under test.
[0012] Optionally, when the radar under test performs transmitting amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a transmitting state. Optionally, when the radar under test performs transmitting amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a transmitting state. Optionally, when the radar under test performs transmitting amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a transmitting state.
[0013] Optionally, when the radar under test performs receiving amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a receiving state. Optionally, when the radar under test performs transmitting amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a transmitting state. Optionally, when the radar under test performs transmitting amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a transmitting state. Optionally, when the radar under test performs transmitting amplitude and phase calibration, the TR component of the radar under test is controlled by the upper computer to remain in a transmitting state.
[0014] In summary, the present application has the following beneficial technical effects: The measurement tool of the present application can be used for phased array amplitude and phase calibration in an external field and a high-low temperature environment, without the need for a scanning frame, a standard horn, a darkroom, and other near-far field test environments, without the need for complex measurement equipment, and with strong anti-interference capability. The tool can realize accurate measurement of full-link receiving sensitivity, full-link receiving gain, and radar transmitting power, and has very small space requirements, so that the radar can measure the above key indicators in environmental tests such as high-low temperature tests. The present application is used to solve the problem that the sensitivity of an active phased array radar system, the system receiving gain, and the system transmitting power cannot be directly measured in a high-low temperature state, and the problem that it is difficult to perform antenna array amplitude and phase calibration in an external field environment and a high-low temperature environment. BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all the other drawings can be obtained by those of ordinary skill in the art without any creative effort based on these drawings.
[0016] Figure 1 Structure block diagram for the measurement tool and the interface of the radar to be measured in the present application; Figure 2 Structure schematic diagram for the measurement antenna array and the metal grid in the present application; Figure 3 Principle block diagram for the sensitivity measurement of the radar to be measured in the embodiments of the present application; Figure 4 Principle block diagram for the transmit power measurement of the radar to be measured in the embodiments of the present application; Figure 5 Principle block diagram for the measurement tool calibration in the embodiments of the present application; Figure 6 Principle block diagram for the transmit amplitude and phase calibration of the radar to be measured in the embodiments of the present application; Figure 7 Principle block diagram for the receive amplitude and phase calibration of the radar to be measured in the embodiments of the present application.
[0017] Legend of reference signs: 1, measurement antenna array; 11, antenna unit; 2, metal grid. DETAILED DESCRIPTION
[0018] The embodiments of the present application will be described in detail below with reference to the drawings.
[0019] The embodiments of the present application are described below through specific and detailed examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and each detail in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.
[0020] It is to be appreciated that the various aspects described herein are capable of implementation by various types of structures and / or functionality. For example, one or more aspects described herein can be implemented by hardware alone (e.g., by an ASIC), by software alone (e.g., by a process running on a processor), or by any combination of hardware and software (e.g., by a process running on a processor and hardware of an ASIC). An implementation of one or more aspects described herein may
[0021] It is also to be appreciated that the figures provided in the following embodiments are merely schematic representations of the basic ideas of the present application, and only show components relevant to the present application, not drawn according to the number, shape and size of the components in actual implementation, and the shapes, number and proportions of the components in actual implementation can be arbitrarily changed, and the layout of the components can be more complex.
[0022] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, one skilled in the art will understand that the described aspects can be practiced without these specific details.
[0023] The embodiment of the present application provides an airborne active phased array weather radar measurement tool.
[0024] As shown in Figure 1 and Figure 2 An airborne active phased array weather radar measurement tool comprises: A measurement antenna array 1 has a plurality of spaced antenna units 11, and the topology of the measurement antenna array 1 is consistent with that of a radar antenna array to be measured.
[0025] A metal grid 2 is fixedly connected to one side of the measurement antenna array 1, and the other side of the metal grid 2 is fixedly connected to the radar antenna array to be measured. The antenna units on the radar antenna array to be measured and the measurement antenna array 1 are one-to-one corresponding to the grids of the metal grid 2. The center of each antenna unit on the radar antenna array to be measured and the measurement antenna array 1 coincides with the center of the corresponding grid. The grid is used to isolate the transmission channels of adjacent antenna units, reduce the mutual interference between the antenna units, and reduce the external electromagnetic interference.
[0026] The output end of the power divider is electrically connected to the antenna units of the measurement antenna array 1.
[0027] A test instrument is electrically connected to the input end of the power divider, and the test instrument is configured to send a radio frequency signal to the radar antenna to be measured through the power divider and the measurement antenna array, or the test instrument is configured to receive a radio frequency signal from the radar antenna to be measured through the power divider and the measurement antenna array.
[0028] The radio frequency signal is transmitted in a closed space during the measurement, and thus there is no requirement for the external electromagnetic environment of the measurement. The measurement scheme does not require far-field / near-field measurement, has no space requirement, and the complete tooling structure is small, and thus the entire tooling can be placed in a temperature chamber to perform system sensitivity and system transmission power measurement under high and low temperature conditions.
[0029] A plurality of metal through holes are arranged around each antenna element of the measurement antenna array, the metal through holes are connected to the ground of the measurement antenna array, the metal through holes are in contact with the metal grid, the metal through holes are punched on the PCB of the measurement antenna array, and the plurality of metal through holes surround a single antenna element to reduce mutual interference between the antenna elements. The metal through holes are arranged along the metal structure of the metal grid.
[0030] The transmission structure of the transmission channel formed by the two antenna elements corresponding to a single grid of the metal grid and the grid is antenna-waveguide-antenna.
[0031] As shown in Figure 3 , the test instrument is a signal source, and the measurement tooling is used for sensitivity measurement of the radar to be measured, and the sensitivity measurement is performed as follows: The TR component of the radar to be measured is controlled to be kept in a receiving state by the upper computer, a signal is injected into the input port of the power division network of the measurement calibration tooling by the signal source, the signal passes through the power divider of the measurement tooling and the measurement antenna array, the antenna of the antenna array of the radar to be measured receives the signal, the transceiver AD of the radar to be measured samples, and the signal amplitude and noise amplitude are obtained after processing by the processor of the radar to be measured and are sent to the upper computer; the signal power injected by the signal source is gradually reduced until the required signal-to-noise ratio threshold is reached, and the signal source input power P in at this time is recorded, and the system sensitivity is P in minus the difference loss of the transmission line, the difference loss of the power divider, and the transmission difference loss between the measurement antenna array and the antenna array of the radar to be measured.
[0032] As shown in Figure 4 , the test instrument is a power meter, and the measurement tooling is used for transmission power measurement of the radar to be measured; and the transmission power measurement is performed as follows: The TR component of the radar to be measured is controlled to be kept in a transmitting state by the upper computer, the radar to be measured transmits a radio frequency signal, and the radio frequency signal is transmitted to the power meter through the transmission channel, the measurement antenna array, and the power divider of the measurement tooling in sequence, and the power meter measures the output power value P outThe transmitting power of the airborne active phased array weather radar is an output power value P outj The difference loss of the transmission line, the difference loss of the power divider, the transmission difference loss between the measurement antenna array and the radar antenna array to be measured are added.
[0033] Before the sensitivity and system transmitting power measurement of the radar to be measured using the measurement tool, the insertion loss of the measurement tool needs to be calibrated and measured in advance. The specific measurement method is as shown in Figure 5 As shown in the figure, the total insertion loss of the two measurement tools is measured by assembling the two measurement tools with each other. Due to the closed nature of each channel, the insertion loss of the measurement tool is basically the reflection of the antenna and the insertion loss of the power dividing network, and the insertion loss of a single measurement tool is half of the measured insertion loss.
[0034] The tester is a vector network analyzer. The two channels of the vector network analyzer are respectively connected to the power divider collection port of the antenna to be measured and the measurement calibration tool, which is used for transmitting amplitude and phase calibration and receiving amplitude and phase calibration of the radar to be measured.
[0035] As shown in Figure 6 When the transmitting amplitude and phase calibration of the radar to be measured is performed, the TR component of the radar to be measured is controlled by the upper computer to remain in the transmitting state. The channels of each TR component are opened one by one. For each opened channel, the amplitude and phase data of the transmitting signal are measured using the vector network analyzer, and the amplitude and phase data of the transmitting signal are recorded by the upper computer. The amplitude and phase of one transmission channel of the radar antenna to be measured are used as the reference to calibrate other transmission channels.
[0036] As shown in Figure 7 When the receiving amplitude and phase calibration of the radar to be measured is performed, the TR component of the radar to be measured is controlled by the upper computer to remain in the receiving state. Each transmission channel is sequentially used as the transmission channel to be measured. When the transmission channel to be measured is measured, the transmission channels other than the transmission channel to be measured are increased by 30 dB attenuation, and the transmission channels other than the transmission channel to be measured which share the same final power divider and are adjacent to each other are grouped into a group. The phase of the two transmission channels in the group is adjusted to 180° phase difference, so that all the channel signals except the transmission channel to be measured and its adjacent channels are substantially canceled out. The vector network analyzer measures the amplitude and phase data of the receiving signal of the transmission channel to be measured, and records the amplitude and phase data of the receiving signal of the transmission channel to be measured by the upper computer. The amplitude and phase of one transmission channel of the radar antenna to be measured are used as the reference to calibrate other transmission channels.
[0037] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical scope disclosed by the present application can be easily conceived by the person skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A measuring fixture for an airborne active phased array weather radar, characterized in that, include: The measuring antenna array has multiple spaced antenna elements, and the topology of the measuring antenna array is consistent with that of the radar antenna array under test. A metal grid is fixedly connected to the measuring antenna array on one side and to the radar antenna array under test on the other side. The antenna elements on both the radar antenna array under test and the measuring antenna array correspond one-to-one with the grid of the metal grid. The center of a single antenna element on both the radar antenna array under test and the measuring antenna array coincides with the center of the corresponding grid. The grid is used to isolate the transmission channels of adjacent antenna elements. The output terminal of the power divider is electrically connected to the antenna element of the measurement antenna array; The test instrument is electrically connected to the input terminal of the power divider. The test instrument is used to transmit radio frequency signals to the radar antenna under test through the power divider and the measurement antenna array, or the test instrument is used to receive radio frequency signals transmitted from the radar under test through the power divider and the measurement antenna array.
2. The airborne active phased array weather radar measurement fixture according to claim 1, characterized in that, Each antenna element of the measurement antenna array is surrounded by several metal through holes, which are connected to the ground of the measurement antenna array and in contact with the metal grid.
3. The airborne active phased array weather radar measurement fixture according to claim 2, characterized in that, The metal through-holes are arranged along the metal structure of the metal grid.
4. The airborne active phased array weather radar measurement fixture according to claim 1, characterized in that, The transmission structure of the radio frequency signal transmission channel formed by the two antenna elements corresponding to a single grid of the metal grid and the grid is antenna-waveguide-antenna.
5. The airborne active phased array weather radar measurement fixture according to claim 1, characterized in that, The tester is a signal source, and the measuring fixture is used to measure the sensitivity of the radar under test. The host computer controls the TR component of the radar under test to remain in the receiving state. The signal source injects a signal into the power divider network input port of the measurement calibration fixture. After the signal passes through the power divider of the measurement fixture and the measurement antenna array, it passes through the transmission channel. The antenna of the radar under test antenna array receives the signal. The transceiver of the radar under test samples the signal. After processing by the processor of the radar under test, the signal amplitude and noise amplitude are obtained and sent to the host computer. Gradually reduce the power of the signal injected into the signal source until the desired signal-to-noise ratio threshold is reached, and record the signal source input power P at this point. in , The system sensitivity is P in Subtract transmission line loss, power divider loss, and transmission loss between the measurement antenna array and the radar antenna array under test.
6. The airborne active phased array weather radar measurement fixture according to claim 1, characterized in that, The tester is a power meter, and the measuring fixture is used to measure the transmit power of the radar under test. The host computer controls the TR component of the radar under test to remain in the transmitting state. The radar under test transmits radio frequency signals, which are transmitted sequentially through the transmission channel, the measurement antenna array, and the power divider of the measurement fixture before being transmitted to the power meter. The power meter measures the output power value P. out ; The transmit power of an airborne active phased array weather radar is the output power value P. outj In addition, there are transmission line losses, power divider losses, and transmission losses between the measurement antenna array and the radar antenna array under test.
7. The airborne active phased array weather radar measurement fixture according to claim 1, characterized in that, The test instrument is a vector network analyzer. The two channels of the vector network analyzer are connected to the antenna under test and the power divider port of the measurement and calibration fixture, respectively, for performing transmit amplitude and phase calibration and receive amplitude and phase calibration on the radar under test.
8. The airborne active phased array weather radar measurement fixture according to claim 7, characterized in that, When performing transmit amplitude and phase calibration on the radar under test, the TR component of the radar under test is kept in the transmit state by controlling the host computer. Each TR component channel is opened individually in sequence. For each opened channel, the amplitude and phase data of the transmitted signal are measured using a vector network analyzer, and the amplitude and phase data of the transmitted signal are recorded by the host computer. The amplitude and phase of one transmission channel of the radar antenna under test are used as a reference to calibrate other transmission channels.
9. The airborne active phased array weather radar measurement fixture according to claim 7, characterized in that, When performing receive amplitude and phase calibration on the radar under test, the TR component of the radar under test is controlled by the host computer to remain in the receiving state. Each transmission channel is then selected as the transmission channel to be tested in turn. When measuring the channel under test, the transmission channels other than the channel under test are attenuated by 30dB. The adjacent transmission channels that share the same final stage power divider are grouped together, and the phase difference between the two transmission channels in a group is adjusted to 180°. A calibration signal is sent to the measurement antenna array through a vector network analyzer. The calibration signal enters the radar under test through the power divider. The vector network analyzer measures the amplitude and phase data of the received signal of the transmission channel under test, and records the amplitude and phase data of the received signal of the transmission channel under test through the host computer. The amplitude and phase of one transmission channel of the radar antenna under test are used as a reference to calibrate other transmission channels.