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A radial line slot antenna without a slow wave structure

1993; Wiley; Volume: 76; Issue: 7 Linguagem: Inglês

10.1002/ecja.4410760709

8756-6621

Katsuei Ichikawa Member, Jun‐ichi Takada, Makoto Ando, N. Goto,

Antenna Design and Analysis

Abstract The radial line slot antenna is a thin circularly polarized antenna intended for satellite broadcast reception, and is expected to be highly efficient in principle. To improve the efficiency, it is necessary to suppress the grating lobe in the 90‐deg direction by means of a slow‐wave structure in the antenna. To this end, styrofoam is mainly used. However, it is more appealing to find a structure without any dielectric material from the viewpoint of heat resistance, fluctuation of the permittivity, and fabrication cost. This paper proposes a radial line slot antenna without a slow‐wave structure in which the wavelength reduction phenomena due to slot coupling analyzed quantitatively are used intentionally. From the analysis, the antenna gain is derived as a function of the antenna thickness (waveguide height), which is the principal parameter for the wavelength reduction effect. It is demonstrated that the grating lobe can be suppressed. Also, by means of an experiment, the antenna efficiency of 61 percent is attained in a hollow configuration so that the viability of this approach is proven.