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Analysis of radial line slot antennas with dielectric layers over the aperture

2003; Wiley; Volume: 87; Issue: 3 Linguagem: Inglês

10.1002/ecja.10169

8756-6621

Kensuke Miyachi, Jiro Hirokawa, Makoto Ando,

Microwave Engineering and Waveguides

Abstract The slot coupling characteristics are analyzed and the aperture distributions are evaluated for several dielectric layers loaded on the upper surface outside the radial line slot antenna. First, for the design of a uniform aperture distribution, mutual coupling is expressed approximately by an infinite array of two‐dimensional slot pairs with equal‐amplitude excitation in a model with periodic boundary walls in the two directions of an external region. Based on this approximation, the slot length and the pair spacing in the radial direction are controlled so as to design an array with a uniform aperture distribution. Next, as a model effective for an arbitrary distribution over a finite aperture, a slot array that is finite in one dimension is analyzed by the spectral domain approach. Also, if the situation with dielectric loading through a gap such as a radome is considered, it is shown that the effect on the aperture distribution can be neglected if a dielectric layer with a thickness reducing the Fresnel reflection coefficient is placed about 1/8 wavelength away. The validity of the analysis and design is confirmed by trial fabrication and measurement at 38 GHz. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(3): 19–27, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ecja.10169