A Phase Center Measurement Method for Broadband Antenna with Symmetrical Main Beam

Abstract

The invention relates to the technical field of electronic reconnaissance direction finding applications, and discloses a phase center measurement method of a broadband antenna with a symmetrical main beam. Establish a two-dimensional rectangular coordinate plane so that the two beam axes are in the coordinate plane, and the two beam axes are symmetrical about one coordinate axis, and the extension line of the two beam axes intersects the coordinate origin; take a point C on the coordinate axis as the axis of symmetry 1 , so that point C 1 are located in the far-field region of both antennas; at point C 1 place frequency f at 0 The radiation source, measure the phase difference φ of the received signal 1 ; will be at point C 1 The radiation source moves in the coordinate plane along the direction perpendicular to the coordinate axis to C 2 point, calculate the radiation source from C 1 move point to C 2 The phase difference change value φ caused after the point 0 ; according to the phase difference change value φ 0 , calculate the coordinate position of the phase center of the antenna under test. The method does not require equipment such as a turntable, has low test conditions, simple test steps and high test efficiency, and provides a new test method for the phase center measurement of broadband antennas commonly used in electronic reconnaissance.

Description

technical field [0001] The invention relates to the technical field of electronic reconnaissance and direction finding applications, in particular to a method for measuring the phase center of a broadband antenna with a symmetrical main beam. Background technique [0002] The electromagnetic wave radiated by the main beam of the antenna can be approximated as radiating from an ideal point source. If the phases of the far-field signal are equal to the equidistant from the point, then the point can be defined as the "phase center" of the antenna. point" (or simply "phase center"). The phase center of the antenna has an important influence on the direction finding application of the interferometer based on the phase comparison method in electronic reconnaissance, because in this direction finding application, multiple broadband unit antennas are used to form an antenna array to form an interferometer, and the electromagnetic target radiation The incoming wave direction of the ...

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Problems solved by technology

In fact, there are still some public documents that introduce various improvement measures for the phase center measurement method of the GNSS receiving antenna. Although there are differences in the specific data processing and analysis, the overall method flow is basically the same. Here no more introductions

[0015] From the above-mentioned summary of current antenna phase center measurement methods, it can be seen that: Type ① The traditional method of determining the antenna phase center through phase pattern testing is relatively standard in operation, but it requires turntables and other supporting equipment, and the test workload is relatively large

Although the second type is based on the three-antenna method and obtains the change law of the phase center of the antenna in the ultra-wide frequency band through six S-parameter measurements, but this method can only determine the relative change of the phase center of the broadband antenna, and it is difficult to determine the antenna under test. The exact location of the phase center

The third type of method is a special method for special objects, especially for the measurement of the phase center of the GNSS global satellite navigation receiving antenna, many unique methods are proposed. This type of method is very targeted and not widely applicable.

From the above three types of methods, the accurate measurement of the phase center of the broadband electronic reconnaissance receiving antenna can use the traditional method based on the phase pattern, but without the assistance of the turntable and other equipment, the phase pattern cannot be obtained accurately, thus limiting use of traditional methods

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