High-isolation circularly polarized balanced radar radio frequency front-end structure

Abstract

The invention relates to a high-isolation circularly polarized balanced radar radio frequency front-end structure, which comprises a two layers of dielectric plates, four 2*2 microstrip chamfered circular polarization antenna subarrays arranged on the top dielectric plate and a feed network arranged on the bottom dielectric plate, and is characterized in that and metal bottoms of the two layers of dielectric plates are connected; and the feed network comprises four feed probes, two annular couplers, two quadrature couplers, a grounding patch, two matched resistors, a signal transmitting terminal and a signal receiving terminal. The high-isolation circularly polarized balanced radar radio frequency front-end structure is simple in structure, low in cost and high in reliability, can easily realize good isolation between the transmitting terminal and the receiving terminal and improves the interference resisting ability. Meanwhile, acting as a balanced radar front-end system, the high-isolation circularly polarized balanced radar radio frequency front-end structure can solve problems of antenna reflection and partial coupling while well realizing leakage cancellation, and can be applied to various radar communication and short-range detection occasion requiring shared transmitting and receiving and high isolation.

Description

technical field [0001] The invention belongs to the technical field of radar communication and short-range detection, in particular to a high-isolation circular polarization balance radar radio frequency front-end structure. Background technique [0002] With the development of technologies such as short-range detection, microelectronics, and high-speed signal processing, the short-range detection continuous wave radar has begun to emerge in the civilian field. Life brings great convenience. Generally, in order to obtain a simpler structure, occupy less space, and reduce costs as much as possible, the general short-range detection continuous wave radar adopts a common antenna structure for sending and receiving. The common antenna for transmitting and receiving is an important part of the short-range detection radar, and it is an indispensable device to realize the good performance of the whole system. However, there are relatively large defects in the shared antenna struc...

AI Technical Summary

Problems solved by technology

However, there are relatively large defects in the shared antenna structure for transmitting and receiving: due to the limited isolation of the circulator used in the shared transmitting and receiving structure, the transmitted signal will leak to the receiving part, which will reduce the accuracy of the system, and even when the leakage is serious, It will make the system misjudgment, so the problem of emission signal leakage becomes the main obstacle to improve the accuracy of short-range detection radar

Among them, the relatively successful combination of passive leakage cancellation and circular polarization is the circular polarization balanced radar technology proposed by Han Lim Lee et al. in recent years. This technology uses passive modules such as quadrature couplers and Lange couplers , six ports, etc., to replace the circulator with a shared and structurally symmetrical network for transmitting and receiving channels, and to use the structural balance symmetry and rationally allocate the phase relationship to achieve the effect of leakage cancellation. Although the structure uses double-feed method to design two circles Polarized antennas, but because the signal energy loss caused by spatial superposition in the antenna array is not considered, the final structure can only achieve linear polarization, and half of the energy is lost

[0004] The current short-range detection radar system does not consider using the passive cancellation network to solve the problem of the leakage of the transmitted signal to achieve the circular polarization characteristics of the common antenna for transmitting and receiving at the same time or to improve the circular polarization characteristics of the transmitting and receiving antenna. The high isolation and circular polarization characteristics of the short-range detection radar can be realized by the cancellation network and the shared antenna for transmitting and receiving, so this radar front-end topology will be greatly applied and developed

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