Horn antenna pattern calibration system and method

Abstract

The embodiment of the invention discloses a horn antenna directional diagram calibration system, which comprises a scanning probe, a rectangular scanning plane, a horn antenna to be measured, a vectornetwork analyzer, a spread spectrum module, a control computer and an optical platform; wherein the scanning probe and the horn antenna to be measured are aligned under a horizontal polarization condition at the same time and are coaxially erected on an antenna frame; the antenna frame is erected on the optical platform; the control computer is used for controlling a scanning frame for erecting ascanning probe, so that the scanning probe moves along the shape of a vertical zigzag line to scan electromagnetic wave signals on each grid point on the rectangular scanning plane along a first direction parallel to the surface of the optical platform and a second direction perpendicular to the first direction by stepping at a certain value; the vector network analyzer is used for receiving theelectromagnetic wave signal passing through the spread spectrum module, measuring the amplitude and phase values of a to-be-measured frequency point on a rectangular scanning plane, and recording theamplitude and phase values; and the control computer converts the measured value and the corresponding position coordinate into a far-field directional diagram of the horn antenna to be measured.

Description

technical field [0001] The present invention relates to the communication field, and more specifically, to a horn antenna pattern calibration system and method. Background technique [0002] The IEEE Std 149 standard specifies the antenna pattern calibration method. Antenna calibration is carried out in a microwave anechoic room. The transmitting antenna and the receiving antenna are set up on the antenna bracket coaxially. The distance between the transmitting antenna and the receiving antenna is d, d Satisfy the far-field condition. Adjust the phase center of the horn antenna under test to coincide with the center of the turntable, [0003] For horn antennas from 75GHz to 110GHz, the IEEE Std 149 standard is used to measure the amplitude pattern, and there are the following deficiencies: [0004] 1. Every time the pattern of the horn antenna is to be tested, it is necessary to find the phase center of the antenna at this frequency point, and coincide the phase center wit...

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Problems solved by technology

[0004] 1. Every time the pattern of the horn antenna is to be tested, it is necessary to find the phase center of the antenna at this frequency point, and coincide the phase center with the center of the rotating shaft of the turntable. Generally, it needs to be moved several times to find the position of the phase center , so it takes a very long time

[0005] 2. The phase center of the horn antenna to be tested is different at each test frequency point, so when measuring the amplitude pattern at each test frequency point, it is necessary to repeat the operation of finding the phase center at each test frequency point. The process is very cumbersome and time-consuming, and the efficiency is relatively low for the pattern test with a large number of test frequency points

[0006] 3. 75GHz~110GHz far-field measurement pattern, the distance between the transmitting antenna and the receiving antenna is long, and the signal attenuation per unit distance in the 75GHz~110GHz frequency band is large, resulting in a small measurement signal. In addition, the main beam of the horn antenna with high frequency is relatively narrow. Strict alignment of the transceiver antenna is required. Due to the small size of the horn, long-distance alignment is difficult. These factors will increase the uncertainty of the antenna pattern measurement.

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