A reflector and difference network antenna

Abstract

The present invention proposes a reflector and difference network antenna. The antenna includes a reflector antenna, a feed source and a sum-difference network, the feed source is connected to the sum-difference network, wherein the feed source adopts a monaural horn, and two or more monaural horns are symmetrically distributed in pairs at the focal point of the reflector antenna. Both sides; the single-ear horn is in the shape of a pyramid horn, and the edge of the bell mouth is extended with a single-ear structure. The novel reflector and difference network antenna proposed by the present invention provides an effective solution for the occlusion of the reflector antenna by the feed source, and can obtain high gain, Low sidelobes, low null depth and highly symmetrical sector and difference beams.

Description

technical field [0001] The invention relates to the field of radio frequency antennas, in particular to a sum-difference network antenna structure using a monaural horn as a feed source. Background technique [0002] In recent years, millimeter-wave radar technology has become increasingly mature. Compared with infrared, millimeter-wave has less atmospheric attenuation, better penetration of smoke and dust, and is less affected by weather. These excellent properties determine that millimeter-wave radar has all-day time All-weather working ability, has a wide range of engineering applications in traffic supervision, security deployment and control, target search and so on. As an important part of millimeter-wave radar, the performance of antenna directly affects the detection and tracking ability of the radar. [0003] Many studies have been carried out on millimeter-wave radar antennas at home and abroad, such as biased feed reflector antennas, multi-beam antennas, and mono...

AI Technical Summary

Problems solved by technology

However, for the positive-fed reflector antenna, the feed horn needs to be installed on the focal point of the paraboloid, which will inevitably block the center of the paraboloid's mouth surface field, reducing the energy of the main lobe of the pattern and causing multiple reflections. Affects the electric field distribution of the surface field at the antenna port, eventually leading to a decrease in the main lobe level of the sum and difference beam, an increase in the side lobe level, and a decrease in antenna gain. In severe cases, the main lobe of the pattern will be deformed

In order to overcome the shortcoming of the feed source shielding of the feedforward antenna, the method of offset feeding can also be used (Offset-parabolic-reflector antennas: A review [J]. Proceedings of the IEEE, 1978, vol.66, no.12, pp.1592-1618), but the offset-fed antenna is not conducive to forming a sum-difference beam with a good shape

This is because the equivalent phase center of the feed source will largely deviate from the focus of the reflector antenna during offset feeding. As the distance between the phase center and the focus of the paraboloid increases, the problem of offset will be serious. On the one hand, it will affect The performance of the sum and difference beam makes the side lobe increase, the beam deformation and the null depth become larger, which is extremely unfavorable for meeting the performance requirements such as high resolution of the antenna; on the other hand, the offset feed makes the design of the antenna structure more difficult. In addition, it is necessary to carry out complex shaping of the horn feed, which eventually leads to an increase in the overall size of the antenna, which makes it difficult to guarantee the fixed installation and service life of the antenna

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