CN116559755A - An array antenna active standing wave test and calibration system and method - Google Patents

Abstract

This application belongs to the field of array antenna measurement technology, and discloses an array antenna active standing wave test calibration system and method, including several vector network analyzers, calibration modules and computer terminals, and several vector network analyzers are divided into two group, respectively as an independent excitation source and receiver. This application uses multiple multi-port vector network analyzers as coherent excitation sources, connects multiple vector network analyzers to the calibration module, obtains multi-channel coherent excitation signals by adjusting the calibration module, and uses the vector network analyzer to directly test the array The standing wave parameters of each antenna unit on the surface; the automatic test shortens the time for the active standing wave test of the front antenna and greatly improves the test efficiency. Based on the standard instrument scheme, the system has good scalability.

Description

An array antenna active standing wave test and calibration system and method

technical field

The present application relates to the technical field of array antenna measurement, and more specifically, relates to an array antenna active standing wave test and calibration system and method.

Background technique

Array antennas are widely used in radar, detection, communication and other systems due to their advantages of high gain and flexible beam. For the evaluation of the performance of the array antenna, the standing wave ratio of the antenna is a very important index. The standing wave ratio reflects the impedance matching degree between the radiation unit and the transmission line and other components. With the scanning of the beam of the phased array antenna, due to the influence of the mutual coupling between the units in the phased array antenna array, the phase relationship between each unit and each other changes, so that at different scanning angles, the S The parameters change accordingly, and generally this change is manifested as the deterioration of the active standing wave performance.

In the test and verification of the antenna array, when different array amplitude and phase excitations achieve different array beam orientations, the actual standing wave level of individual array elements deteriorates sharply, which can lead to self-excitation or even burn. In the past, when testing the standing wave of the array, the test equipment either tested the passive standing wave test that stimulated a single array element while other antenna elements were connected to the load, or passed the test of the passive standing wave and the full S parameters of the antenna array. The theoretical formula calculates the active standing wave. Conventional standing wave ratio measurement methods only measure the performance of isolated antenna elements when they are fed, but considering the mutual coupling effect between elements, the standing wave ratio when the entire array is fed is different from that of isolated elements. Therefore, measurements of isolated elements cannot accurately assess the performance of the entire array.

In addition, in the field of array antenna testing, some units have proposed the configuration of a vector network analyzer with one RF source and two ports, combined with customized beam control modules, coupling network modules, and switch network modules, to construct multiple In this type of system, non-standard customized modules account for a large proportion. On the one hand, due to the poor stability of non-standard customized modules, third-party measurement and calibration cannot be performed. On the other hand, customized modules The cost is high, and the scalability is not strong. It is difficult to upgrade and transform later, which often leads to waste of resources and is not conducive to asset value preservation.

Contents of the invention

The workload of the array antenna standing wave test is huge. There is a big difference between the previous method and the active standing wave situation under the actual amplitude and phase excitation of the antenna array. The traditional array antenna active standing wave test system has a large number of Non-standard customized modular units, the cost of the whole system is high, and it cannot be calibrated by a third-party measurement agency, the scalability is poor, and it is easy to cause waste of resources. How to improve the active standing wave test efficiency of array antennas and reduce the test cost has become an urgent problem for the industry to solve. In order to solve the above problems, the present application provides an array antenna active standing wave test and calibration system and method.

An array antenna active standing wave test and calibration system and method provided by this application adopts the following technical scheme:

An active standing wave test and calibration system for an array antenna, comprising several vector network analyzers, a calibration module and a computer terminal, wherein several vector network analyzers are divided into two groups, which are respectively used as independent excitation sources and receivers;

The computer terminal is connected to the control port of the vector network analyzer and the calibration module respectively through an Ethernet switch;

The output port of the multi-port vector network analyzer as the excitation source is connected to the input end of the calibration module;

Ports 1 and 2 of the vector network analyzer as a receiver are respectively connected to the front and rear ports of the calibration module, and its ports 3 and 4 are respectively connected to the Ref1 and Ref2 ports of the calibration module;

The output port of the calibration module is connected to the test port of the array antenna.

Further, the calibration module includes a radio frequency switch matrix unit, a coupler unit and a coherent synchronization unit.

Further, the coherent synchronization unit includes several reference source modules, which are used to sequentially complete the coherent synchronization and phase control of multiple vector network analyzers.

Further, a power divider is provided between the vector network analyzer as the excitation source and the calibration module, for measuring the amplitude difference and phase difference between the vector network analyzers and each channel of the calibration module.

Further, it also includes an electronic calibration unit and a power meter, the power meter is connected to the USB interface of the vector network analyzer as an excitation source, the electronic calibration unit is connected to the calibration module through a radio frequency line, and is connected to the The USB interface of the vector network analyzer is connected to perform source output power, receiver power and receiver linearity calibration operations.

A kind of array antenna active standing wave test calibration method, described method comprises the following steps:

S1, carrying out full two-port calibration on ports 1 and 2 of the first group of vector network analyzers as the excitation source;

S2. Connect the output ports 1-n of the first group of vector network analyzers to the source ports of the calibration module respectively;

S3, setting the start and end frequencies and the number of measurement points of the standing wave test;

S4. Measure the amplitude difference and phase difference between the corresponding ports of each vector network analyzer and each channel of the calibration module, and perform inherent error calibration of the calibration module.

S5. Calibrate the source output power, receiver power and receiver linearity, and complete the calibration operations of each channel of the calibration module in turn;

S6. Perform a standing wave test through the computer terminal, control the internal switching channel path of the calibration module, and measure the ratio between the forward and backward channels in sequence, so as to obtain the standing wave measurement results of each channel.

Further, the inherent error calibration of the calibration module in the S4 includes the following steps:

S401. Calibrate the S-parameters of ports 1 and 2 of the second group of vector network analyzers using electronic calibration components;

S402. Connect port 1 of the vector network analyzer 1 of the first group to an external power splitter, connect the output 1 of the power splitter to the source 1 port of the calibration module, and connect the calibration modules Ref1 and Ref2 to the vector of the second group respectively Ports 3 and 4 of the network analyzer, connect the measurement channels 1 and 5 of the calibration module to ports 1 and 2 of the vector network analyzer of the second group respectively;

S403. Connect the output 2 of the power divider to the source 5 port of the calibration module, measure the amplitude difference and phase difference of Ref1 and Ref2 of the first group of vector network analyzers 1 and 2 respectively, and measure the amplitude of channels 1 and 5 of the calibration module difference and phase difference;

S404. Connect the output 2 of the power divider to the source 9 port of the calibration module, respectively measure the amplitude difference and phase difference of Ref1 and Ref2 of the first group of vector network analyzers 1 and 2, and measure the channel 1 and 9 of the calibration module. Amplitude difference and phase difference.

Further, the calibration of source output power, receiver power and receiver linearity in said S5 includes the following steps:

S501. Connect the output ports 1 to 4 of the calibration module with the second group of vector network analyzers through the electronic calibration unit, and calibrate each port in turn;

S502. Connect the electronic calibration unit and the USB power meter to the first group of vector network analyzers 1, and calibrate the S parameters and power of ports 1 to 4;

S503. Connect the output ports 4n+1 to 4n+4 (n≥1) of the calibration module in sequence with the second group of vector network analyzers through electronic calibration components, and calibrate each port in sequence;

S504. Connect the electronic calibration unit and the USB power meter to the first group of vector network analyzers n+1, and calibrate the S parameters and power of the ports 1-4.

Further, the standing wave test method includes the following steps in the S6:

S601. Connect the calibration module to the array antenna to be tested;

S602. Adjust the configuration of the calibration module according to the phase difference between the second group of vector network analyzers Ref1 and Ref2, and set the phase value between the first group of vector network analyzers;

S603, using the second group of vector network analyzers to collect forward and backward test results, sequentially adjust the internal channel switching of the calibration module, and record relevant test results;

S604, switch frequency points, repeat S602-S603, and obtain active standing wave test results at different frequencies.

In summary, the present application includes at least one of the following beneficial technical effects:

(1) This application uses multiple multi-port vector network analyzers as coherent excitation sources, connects multiple vector network analyzers to the calibration module, and obtains multi-channel coherent excitation signals by adjusting the calibration module. Directly test the standing wave parameters of each antenna unit in the array; the automatic test shortens the time for the active standing wave test of the array antenna and greatly improves the test efficiency;

(2) This application proposes a method for coherent synchronization between multiple vector network analyzers. In the array antenna test system, the coherent output excitation sources are all composed of independent excitation sources inside the vector network analyzer, and standardized instruments and equipment are adopted. The system index parameters are guaranteed, and the possibility is provided for third-party measurement, and the system has good scalability, which effectively reduces the test cost and post-maintenance cost.

Description of drawings

Fig. 1 is the connection schematic diagram of the test calibration system of the present application;

Fig. 2 is a schematic flow chart of the test and calibration method of the present application;

FIG. 3 is a schematic flow chart of the inherent error calibration of the calibration module in S4 of the present application;

Fig. 4 is a schematic flow chart of calibrating source output power, receiver power and receiver linearity in S5 of the present application;

FIG. 5 is a schematic flowchart of the standing wave test method in S6 of the present application.

Detailed ways

The technical solutions in the embodiments of the application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the application; obviously, the described embodiments are only some of the embodiments of the application, not all of them, based on The embodiments in the present application and all other embodiments obtained by persons of ordinary skill in the art without creative efforts belong to the protection scope of the present application.

In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "top/bottom", etc. are based on the orientations shown in the drawings Or positional relationship is only for the convenience of describing the present application and simplifying the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "set with", "set/connected", "connected", etc. should be understood in a broad sense, such as " Connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be an internal connection between two components. connectivity. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

Example 1:

The present application will be described in further detail below in conjunction with accompanying drawings 1-5.

The embodiment of the present application discloses an array antenna active standing wave test and calibration system, including several vector network analyzers, calibration modules and computer terminals. Several vector network analyzers are divided into two groups, and the first group of vector network analyzers is used as The excitation source used is composed of n sets of 4-port vector network analyzers. Common vector network analyzers have 2/4 independent signal sources. For the same vector network analyzer, internal signal sources are required to have coherent output characteristics ; The second group of vector network analyzers consists of a 4-port vector network analyzer, used as 4 independent receivers;

The computer terminal is connected to the control port of the vector network analyzer and the calibration module respectively through an Ethernet switch;

The output ports of the first group of multi-port vector network analyzers used as excitation sources are connected to the input ends of the calibration module;

Ports 1 and 2 of the second group of vector network analyzers as receivers are respectively connected to the forward and backward ports of the calibration module, and its ports 3 and 4 are respectively connected to the Ref1 and Ref2 ports of the calibration module;

The output port of the calibration module is connected with the test port of the array antenna.

Further, the calibration module includes a radio frequency switch matrix unit, a coupler unit and a coherent synchronization unit.

Further, the coherent synchronization unit includes several reference source modules, which are used to sequentially complete the coherent synchronization and phase control of multiple vector network analyzers.

Further, a power divider is provided between the vector network analyzer as the excitation source and the calibration module, for measuring the amplitude difference and phase difference between the vector network analyzers and each channel of the calibration module.

Further, it also includes an electronic calibration unit and a power meter, the power meter is connected to the USB interface of the vector network analyzer as an excitation source, the electronic calibration unit is connected to the calibration module through a radio frequency line, and is connected to the USB interface of the vector network analyzer. Connections for source output power, receiver power, and receiver linearity calibration operations.

The implementation principle of an array antenna active standing wave test and calibration system and method in the embodiment of the present application is as follows: through the user-defined port configuration of the vector network analyzer, the receiver of the second group of vector network analyzer b1 is defined as logical port 1 A receiver of the second set of vector network analyzer b2 is defined as the b receiver of logical port 1, which is convenient to operate. Use the measurement result of the vector network analyzer user interface S11 as the antenna test result, and set it through the vector network analyzer The standing wave test can be completed through the trace. By switching the internal RF switch of the calibration module, the standing wave measurement of each antenna on the front can be completed in sequence; by adjusting the output phase of the reference source module inside the calibration module, the measurement of multiple vector network analyzers can be completed in sequence. Coherent synchronization and phase control; by calibrating the internal directional coupler unit of the module, the measurement port excitation signal and reflected signal measurement functions are completed.

This embodiment also discloses a method for testing and calibrating an active standing wave of an array antenna, which includes the following steps:

S1, carrying out full two-port calibration on ports 1 and 2 of the first group of vector network analyzers as the excitation source;

S2. Connect the output ports 1-n of the first group of vector network analyzers to the source ports of the calibration module respectively. The corresponding relationship is that vector network analyzer 1 is connected to source 1-4 ports, and vector network analyzer 2 is connected to source 5-8 , and so on, the vector network analyzer n is connected to the source 4n-3~4n;

S3. Set the start and stop frequency of the standing wave test, the number of measurement points, etc. in the control software;

S4. Measure the amplitude difference and phase difference between the corresponding ports of each vector network analyzer and each channel of the calibration module, and perform inherent error calibration of the calibration module.

S5. Calibrate the source output power, receiver power and receiver linearity, and complete the calibration operations of each channel of the calibration module in turn;

S6. Perform a standing wave test through the computer terminal, control the internal switching channel path of the calibration module, and measure the ratio between the forward and backward channels in sequence, so as to obtain the standing wave measurement results of each channel.

Further, the inherent error calibration of the calibration module in S4 includes the following steps:

S401. Connect two test cables to ports 1 and 2 of the second group of vector network analyzers, connect the USB of the electronic calibration unit to the USB interface of the second group of vector network analyzers, and select the vector network analyzer for full two-port calibration The function is to calibrate the S parameters of ports 1 and 2; it should be noted that the output ports of the first group of vector network analyzers 1~n are respectively connected to the source ports of the calibration module, and the corresponding relationship is that vector network analyzer 1 is connected to Source 1~4 ports, vector network analyzer 2 connects to sources 5~8, and so on, vector network analyzer n connects to sources 4n-3~4n.

S402. Connect port 1 of the vector network analyzer 1 of the first group to an external power splitter, connect the output 1 of the power splitter to the source 1 port of the calibration module, and connect the calibration modules Ref1 and Ref2 to the vector of the second group respectively Ports 3 and 4 of the network analyzer, connect the measurement channels 1 and 5 of the calibration module to ports 1 and 2 of the vector network analyzer of the second group respectively;

S403. Connect the output 2 of the power divider to the source 5 port of the calibration module, measure the amplitude difference and phase difference of Ref1 and Ref2 of the first group of vector network analyzers 1 and 2 respectively, and measure the amplitude of channels 1 and 5 of the calibration module difference and phase difference;

S404. Connect the output 2 of the power divider to the source 9 port of the calibration module, respectively measure the amplitude difference and phase difference of Ref1 and Ref2 of the first group of vector network analyzers 1 and 2, and measure the channel 1 and 9 of the calibration module. Amplitude difference and phase difference.

Further, the calibration of source output power, receiver power and receiver linearity in S5 includes the following steps:

S501. Connect the output ports 1 to 4 of the calibration module to the electronic calibration unit through the radio frequency line, and connect the electronic calibration unit to the USB interface of the second group of vector network analyzers, respectively at channels 1/2/3/4. One-port calibration; connect the electronic calibration module to the USB of the first group of vector network analyzers 1 for full four-port S-parameter calibration; connect the power meter to the USB of the first group of vector network analyzers 1 for source Output power, receiver power and receiver linearity calibration operations;

S502. Connect the channel 5/6/7/8 port of the calibration module to the electronic calibration unit through the radio frequency cable, and connect the electronic calibration unit to the USB interface of the second group of vector network analyzers, respectively on channels 5/6/7/ Perform single-port calibration at 8 locations; connect the electronic calibration module to the USB of the first group of vector network analyzers 2 for full four-port S-parameter calibration; connect the power meter to the USB of the first group of vector network analyzers 2, Carry out the source output power, receiver power and receiver linearity calibration operations respectively; complete the calibration operations of other channels of the calibration module in turn;

S503. Connect the output ports 4n+1 to 4n+4 (n≥1) of the calibration module in sequence with the second group of vector network analyzers through electronic calibration components, and calibrate each port in sequence;

S504. Connect the electronic calibration unit and the USB power meter to the first group of vector network analyzers n+1, and calibrate the S parameters and power of the ports 1-4.

Further, the standing wave test method in S6 includes the following steps:

S601. Connect the calibration module to the array antenna to be tested;

S602. Adjust the configuration of the calibration module according to the phase difference between the second group of vector network analyzers Ref1 and Ref2, and set the phase value between the first group of vector network analyzers;

S603, using the second group of vector network analyzers to collect forward and backward test results, sequentially adjust the internal channel switching of the calibration module, and record relevant test results;

S604, switch frequency points, repeat S602-S603, and obtain active standing wave test results at different frequencies.

It should be noted that, if you click the standing wave test in the control software, the system will automatically set the output frequency of the first/second group of vector network analyzers, and at the same time set the first/second group of vector network analyzers to work in CW mode, the first group The vector network analyzer uses the manual trigger mode, adjusts the phase difference between channels 1 and 5 of the first group of vector network analyzers according to the phase difference between the second group of vector network analyzers Ref1 and Ref2, and adjusts the internal switching channel of the calibration module Path, repeatedly measure the phase difference between Ref1 and Ref2, adjust the phase difference between channel 1 and n of the first group of vector network analyzers in turn, until the first group of vector network analyzers reaches the coherent state; control the calibration module The channel path is switched internally, and the ratio between the forward and backward channels is measured sequentially, so as to obtain the standing wave measurement results of each channel.

All of the above are preferred embodiments of the application, and are not intended to limit the protection scope of the application. Therefore, all equivalent changes made according to the structure, shape, and principle of the application should be covered by the protection scope of the application. Inside.

Claims (9)

1. a kind of array antenna active standing wave test calibration system, it is characterized in that: comprise some vector network analyzers, calibration module and computer terminal, some described vector network analyzers are divided into two groups, respectively as independent excitation source and receivers; The computer terminal is connected to the control port of the vector network analyzer and the calibration module respectively through an Ethernet switch; The output port of the multi-port vector network analyzer as the excitation source is connected to the input end of the calibration module; Ports 1 and 2 of the vector network analyzer as a receiver are respectively connected to the front and rear ports of the calibration module, and its ports 3 and 4 are respectively connected to the Ref1 and Ref2 ports of the calibration module; The output port of the calibration module is connected to the test port of the array antenna. 2 . The array antenna active standing wave test and calibration system according to claim 1 , wherein the calibration module includes a radio frequency switch matrix unit, a coupler unit and a coherent synchronization unit. 3 . 3. A kind of array antenna active standing wave test calibration system according to claim 2, is characterized in that: described coherent synchronous unit comprises some reference source modules, is used for completing the phase of a plurality of vector network analyzers successively Reference synchronization and phase control. 4. A kind of array antenna active standing wave test and calibration system according to claim 1, is characterized in that: also be provided with active power divider between the described vector network analyzer as excitation source and calibration module, be used for measuring The amplitude difference and phase difference between each vector network analyzer and each channel of the calibration module. 5. A kind of array antenna active standing wave test and calibration system according to claim 1, is characterized in that: also comprise electronic calibration unit and power meter, described power meter and described vector network analyzer as excitation source The electronic calibration unit is connected to the calibration module through a radio frequency line, and is connected to the USB interface of the vector network analyzer for source output power, receiver power and receiver linearity calibration operations . 6. An array antenna active standing wave test calibration method is characterized in that: the method comprises the following steps: S1, carrying out full two-port calibration on ports 1 and 2 of the first group of vector network analyzers as the excitation source; S2. Connect the output ports 1-n of the first group of vector network analyzers to the source ports of the calibration module respectively; S3, setting the start and end frequencies and the number of measurement points of the standing wave test; S4. Measure the amplitude difference and phase difference between the corresponding ports of each vector network analyzer and each channel of the calibration module, and perform inherent error calibration of the calibration module. S5. Calibrate the source output power, receiver power and receiver linearity, and complete the calibration operations of each channel of the calibration module in sequence; S6. Perform a standing wave test through the computer terminal, control the internal switching channel path of the calibration module, and measure the ratio between the forward and backward channels in sequence, so as to obtain the standing wave measurement results of each channel. 7. A kind of array antenna active standing wave test and calibration method according to claim 6, is characterized in that: in the described S4, the inherent error calibration to calibration module comprises the following steps: S401. Calibrate the S-parameters of ports 1 and 2 of the second group of vector network analyzers using electronic calibration components; S402. Connect port 1 of the vector network analyzer 1 of the first group to an external power splitter, connect the output 1 of the power splitter to the source 1 port of the calibration module, and connect the calibration modules Ref1 and Ref2 to the vector of the second group respectively Ports 3 and 4 of the network analyzer, connect the measurement channels 1 and 5 of the calibration module to ports 1 and 2 of the vector network analyzer of the second group respectively; S403. Connect the output 2 of the power divider to the source 5 port of the calibration module, measure the amplitude difference and phase difference of Ref1 and Ref2 of the first group of vector network analyzers 1 and 2 respectively, and measure the amplitude of channels 1 and 5 of the calibration module difference and phase difference; S404. Connect the output 2 of the power divider to the source 9 port of the calibration module, respectively measure the amplitude difference and phase difference of Ref1 and Ref2 of the first group of vector network analyzers 1 and 2, and measure the channel 1 and 9 of the calibration module. Amplitude difference and phase difference. 8. A kind of array antenna active standing wave test and calibration method according to claim 6, is characterized in that: in described S5, calibration of source output power, receiver power and receiver linearity comprises the following steps: S501. Connect the output ports 1 to 4 of the calibration module with the second group of vector network analyzers through the electronic calibration unit, and calibrate each port in turn; S502. Connect the electronic calibration unit and the USB power meter to the first group of vector network analyzers 1, and calibrate the S parameters and power of ports 1 to 4; S503. Connect the output ports 4n+1 to 4n+4 (n≥1) of the calibration module in sequence with the second group of vector network analyzers through electronic calibration components, and calibrate each port in sequence; S504. Connect the electronic calibration unit and the USB power meter to the first group of vector network analyzers n+1, and calibrate the S parameters and power of the ports 1-4. 9. A kind of array antenna active standing wave test calibration method according to claim 6, is characterized in that: standing wave test method comprises the following steps in the described S6: S601. Connect the calibration module to the array antenna to be tested; S602. Adjust the configuration of the calibration module according to the phase difference between the second group of vector network analyzers Ref1 and Ref2, and set the phase value between the first group of vector network analyzers; S603, using the second group of vector network analyzers to collect forward and backward test results, sequentially adjust the internal channel switching of the calibration module, and record relevant test results; S604, switch frequency points, repeat S602-S603, and obtain active standing wave test results at different frequencies.