Reflector surface sum-difference network antenna

Abstract

The invention provides a reflector sum-difference network antenna. The antenna comprises a reflector antenna, a feed source and a sum-difference network; the feed source is connected to the sum-difference network, the feed source adopts a monaural horn, and more than two monaural horns are symmetrically distributed on two sides of a focus of the reflector antenna in pairs; the single-ear horn is in the shape of a pyramid horn, and the edge of the horn mouth extends to form a single-ear structure. According to the novel reflector sum-difference network antenna provided by the invention, an effective solution is provided for the shielding problem of a feed source to a reflector antenna, and fan-shaped sum-difference beams which are high in gain, low in side lobe, low in zero value depth and highly symmetrical can be obtained while the offset of the feed source phase center relative to the focus of the reflector is reduced.

Description

technical field [0001] The invention relates to the field of radio frequency antennas, in particular to a sum and 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 less affected by weather. These excellent performances determine that millimeter-wave radar has all-weather With all-weather working ability, it has a wide range of engineering applications in traffic supervision, security deployment and control, and target search. As an important part of the millimeter-wave radar, the performance of the antenna directly affects the detection and tracking capabilities of the radar. [0003] Many researches have been done on millimeter-wave radar antennas at home and abroad, such as offset reflector antennas, multi-beam antennas, ...

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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