Multilayer dielectric cavity antenna design for wide bandwidth

Abstract

The dimension optimization of a rectangular cavity antenna is presented in this letter. The cavity antenna is fabricated in a multilayer substrate. The antenna operation is based on lowest order TE101 cavity mode. The antenna performance can be predicted using a simple equivalent model for a dielectric cavity. The estimated antenna bandwidth using the quality-factor of the cavity model indicates that the larger aperture and thinner thickness is the wider bandwidth becomes. In this letter, however, the aperture size is limited to operating in a single mode. The antenna sample is fabricated in multilayer FR4 substrates with a dielectric constant of 4.4, so that it operates at 7.2 GHz. The antenna with enhanced bandwidth has an aperture size of 32 x 10 mm2 and total thickness of 4.3 mm. The measured 10-dB bandwidth is 12.1% and the radiation pattern confirms that it operates in a single mode. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2046-2049, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27022