Small global positioning system patch antennas with self-biased NiCo-ferrite films

Abstract

Magneto-dielectric substrates with thin ferrite films show great potential in realizing small antennas with improved omni-directional performance than those realized on dielectric substrates.This article introduces self-biased NiCo-ferrite films as a practical means to tune a patch antenna by loading a commercially available dielectric substrate. Novel antenna designs with self-biased ferrite films were investigated, and these magnetic antennas have improved the axial ratio from 1.45 to 1.0 dB with respect to the central frequency ranging from 1.575 to 1.561 GHz in the simulations. Experimental global positioning system patch antennas with/without ferrite films were fabricated and tested. The measured results demonstrate that antennas with ferrite films can miniaturize the geometrical dimension by shifting down the resonance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1162–1165, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25909