Structure And Classification Of Horn Antenna

- Dec 14 2017 - The horn antenna is a kind of widely used microwave antenna. Its advantages are simple structure, wide bandwidth, large power capacity, easy adjustment and use. Reasonable selection of horn size
Good radiation characteristics can be obtained: a fairly sharp main lobe, smaller sidelobe and higher gain. Therefore, the horn antenna is widely used in military and civil applications. It is a common test antenna.
The basic form of horn antenna is to open side of the rectangular waveguide and the circular waveguide has gradually formed, as is the opening surface of the waveguide expands gradually, to improve the matching of waveguide and free space, the reflection coefficient of the waveguide is small, most of the energy transmission in the waveguide by the loudspeaker radiates out the reflected energy is very small.
In principle, the waveguide open end and the horn antenna are very simple antennas, but it is very difficult to strictly solve their aperture field and external field. First, the field distribution of the waveguide end face and the bell mouth surface is different from the field distribution in the infinite waveguide, and the TEM wave propagating in the space is also different, which is a more complex wave. Secondly, there is a reflection wave on the surface of the mouth except the incident wave. In addition, there is a high - order wave in the mouth, except the main wave. In addition, due to the open structure of the waveguide and the horn, there is current in the edge of the opening of the waveguide and the opening of the horn and the outer wall, and they are also involved in the radiation.
The horn antenna can be divided into four types:
(1) a trumpet fed by a circular waveguide is generally a conical horn;
Secondly, the rectangular waveguide feed horn can be divided into three kinds of speakers according to the different forms of expansion, that is, the E sector fan-shaped horn (formed by the expansion of its narrow edges), the H sector fanned horn (the expansion of its wide edge), and the pyramidal horn (its wide sides and narrow sides are expanded).
(3) TEM horn;
Ridge Waveguide Horn