Novel Schemes For Sidelobe Reduction In Horn Antennas
A numerical technique based on the moment method is used to study different schemes for reducing the E-plane sidelobe and backlobe power levels of waveguides and horn antennas by attaching elliptic and spiral shaped flanges to the aperture edges of these antennas. It is shown that a flared spiral flange attached to the edges of a rectangular waveguide can produce a very wide half power beam-width of 160° and backlobes as low as − 30dB which is highly desirable for compact range applications. A second horn design is also investigated whereby the aperture edges of the horn are shielded by a specially designed metallic cap, hence isolating the edge diffracted fields and minimizing their interference. A reduction in some sidelobes of more than 20dB is achieved by the so called ‘capped-edge’ horn. The final design investigated deals with introducing an active source placed at an optimum position inside the horn and having a particular phase excitation relative to the edge fields. These active sources, which are simulated by magnetic line sources, radiate fields that interfere with the fields incident from the feed wave guide on the edges of the horn. Such a design provides more than 18 dB sidelobe reduction as well as flexibility in shaping the horn pattern. © 1989 Taylor & Francis Ltd.
International Journal of Electronics
Number of Pages
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Chamma, W. A. and Hamid, M., "Novel Schemes For Sidelobe Reduction In Horn Antennas" (1989). Scopus Export 1980s. 337.