Design of a miniaturized dual-band antenna for improved directivity using a dielectric-loaded cavity

Abstract

This article proposes the design of a dual-band global positioning system (GPS) antenna using a high-permittivity dielectric-loaded cavity. The cavity structure is filled with a dielectric material to miniaturize the size, and its width and depth are adjusted to maximize the front-to-back ratio for high directivity. Dual-band circular polarization characteristics are achieved by placing two radiating polygon loops at the aperture of the cavity, and the loops are electromagnetically coupled to a microstrip line for a coupled feeding network. The proposed antenna is fabricated, and its antenna characteristics are measured in a full anechoic chamber. The results demonstrate that the antenna is suitable for dual-band GPS applications with high bore-sight gain values of 3.4 dBic at 1.2276 GHz and 3.7 dBic at 1.5754 GHz.