The Research Of Dual Polarized Probe Applied In Near Field Measurement System

Wide band dual polarized probe used to measure both two polarized components is needed in measuring system with high accuracy nowadays. The band of a probe must be large than that of the antenna to be measured, which is capable of ensuring the convenience of its installing and calibration. A probe also needs well directivity pattern, polarized purity, return loss, and isolation. On the basis of technique needs, this paper proposed a design of a dual polarized wide band antenna, which is used in dual polarized probe in measurement systems.This paper mainly studies horn antenna used as probe in measuring systems. The designed probes are realized by both conical and pyramid horn antenna with ridge structure. According to the theory of waveguide, this article commences the analysis of design principle and best size of both conical and pyramid horn antennas. In accordance with the theory of ridged waveguide, we presented the way of adding ridge structure to expand the frequency band of designed antennas. A dual-ridged horn antenna is designed. A quadrupleridged horn antenna is presented as well. It has the performance of dual polarizing. Compared with traditional horn antennas, the designed antenna has wide band, dual polarized performance and compact size, which meets the need of practical application.Then we optimize the quadruple ridged horn antenna via adding rectangle matching piece, feeding probe and optimizing ridge curve. The proposed antenna has a working frequency range of 1.5~4.2GHz, which ensures fine VSWR, isolation and directivity pattern.On the basis of designed dual polarized probe, we optimize its feeding structure. The way of Balance feeding improves the cross polarization of designed antenna. Polarization performance is assured by feeding with an OMT, whose return loss is under-23 dB and isolation is above 51 dB.This paper aims at research of dual polarized probes used in near field measuring systems. Simulation results of proposed quadruple conical horn antenna and conical horn probe fed by an OMT both reach design requirement, which proves the design is feasible...