A low frequency compact field feed source based on feed network

Abstract

The invention relates to a feed network-based low-frequency compact range feed source, which comprises an ultra-broadband orthogonal dipole antenna (1), a feed network (2), a reflective plate (3), an elliptic cylinder opening surface (4), a support structure (5), a flange plate (6) and a wave-absorbing material (7). The feed source constructs a relatively stable feed source radiation pattern by the elliptic opening surface with a specific length-width ratio, and achieves the characteristics of relatively large 3dB beam width of a horizontal direction pattern and relatively small 3dB beam width of a vertical direction pattern on two different incident polarizations. By introducing a broadband feed network, the length of a feed source horn is greatly reduced. Ultra-broadband oscillators are excited through the feed network; and <e>TE<11> and <o>TE<11> modes with higher mode purity are excited. A support post with a certain length is configured behind the horn antenna of the feed source; the opening surface of the horn antenna is far away from a feed source bracket; a wave-absorbing material with a specific size is added to the bottom part of the support post; and multiple radiation caused by a complicated metal structure of the feed source bracket is inhibited. The feed source mainly works at a low frequency; and the specific frequency range is (300MHz-500MHz).

Description

technical field [0001] The invention relates to the technical field of a compact field feed source, in particular to a low-frequency compact field feed source based on a feed network. Background technique [0002] With the continuous development of the compact field technology, the size of the compact field reflective surface is continuously increasing, and the corresponding compact field quiet zone is also continuously increasing. While the compact field technology is progressing, users also hope that the large-aperture compact field reflector can work at low frequencies, so it can measure the antenna and radar cross section from low frequency to the meter wave band. The original low-frequency feed source is too large in the axial direction when the frequency is lower than 500MHz. Typical examples are TEM horns and pyramidal four-ridge waveguide horns. This type of horn antenna generally requires the axial length to be about 1 wavelength of the lowest operating frequency. ...

AI Technical Summary

Problems solved by technology

The original low-frequency feed source has too large axial dimension when the frequency is lower than 500MHz. Typical examples are TEM horn and pyramid four-ridge waveguide horn. This kind of horn antenna generally requires the axial length to be about 1 wavelength of the lowest operating frequency. When working at 300MHz, the length of the antenna reaches nearly one meter, which will make the entire antenna too large in size and heavy in weight, which will inevitably affect the ease of use of the antenna

At the same time, such a feed will be difficult to mount on a feed stand and be compatible with other band feeds

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