Method and system for semi-physical determination of passive intermodulation power density of large-aperture mesh antenna

Abstract

The invention provides a semi-physical determination method and system for the passive intermodulation power density of a large-caliber mesh antenna, so as to realize passive intermodulation analysisand evaluation of the equal-amplitude dual-carrier incidence large-caliber mesh antenna. The method comprises the steps that frequency domain electromagnetic field simulation is carried out on the large-caliber mesh antenna at the carrier center frequency to acquire the surface power density distribution of the mesh antenna; the relative positions of the large-caliber mesh antenna and a feed source are combined; the normal angle section between the carrier incident direction and the mesh reflection surface is acquired; based on the simulation result, the passive intermodulation experimental measurement matrix of a metal mesh sample is constructed; the passive intermodulation measurement system of the metal mesh sample is used to realize passive intermodulation measurement of the metal meshsample corresponding to the measurement matrix; according to the measurement result, the functional relationship between the passive intermodulation of the metal mesh and the surface power density ofthe mesh antenna is fitted; the large-caliber mesh antenna is divided into different areas according to the power density; and a fitting function is put in to acquire the power density of the passiveintermodulation of the mesh antenna at the feed source port. The passive intermodulation power density of the large-caliber mesh antenna is determined.

Description

technical field [0001] The invention relates to a semi-physical method and system for determining the passive intermodulation power density of large-diameter mesh antennas, belonging to the field of antenna passive intermodulation. Background technique [0002] Passive intermodulation (PIM, Passive Intermodulation) refers to under high power conditions, when two or more carriers are input, the carrier signals are mutually modulated due to the nonlinearity of microwave passive components, resulting in a combination of carrier frequencies product phenomenon. In the space-borne communication system shared by sending and receiving, if the intermodulation products generated between different carriers of the transmitted signal fall into the receiving frequency band, the intermodulation products will enter the receiver at the same time as the received signal, forming interference, which cannot be achieved by traditional filtering and isolation methods. solve. At this time, the pa...

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Problems solved by technology

[0005] The technical problem solved by the present invention is to overcome the fact that the current method for determining the passive intermodulation power density of large-diameter mesh antennas does not consider the power distribution on the actual reflection surface, and the error is very large when the mesh antenna aperture is tapered. , can not realize the deficiency of accurately determining the passive intermodulation power density of the large-diameter mesh antenna, the present invention provides a semi-physical method and system for determining the passive intermodulation power density of the large-diameter mesh antenna, combining electromagnetic simulation and metal The net sample passive intermodulation experiment not only ensures the accuracy of the results, but also realizes the convenience of determining the passive intermodulation power density of large-diameter mesh antennas, and effectively solves the problem of accurate passive intermodulation power density of large-diameter mesh antennas. sure problem

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