Loop-Shaped Patch Antenna for Conformal Arrays to Minimize the Effects of Adjacent Conducting Skin

Abstract

This article proposes a novel method of designing a loop-shaped slot patch antenna using an extended cavity structure to reduce the influence of adjacent conducting vehicle skin. The proposed antenna consists of the radiating patch, loop shaped slot, and an extended cavity structure. The radiating patch is directly connected to a hybrid chip coupler to achieve a circular polarization property, and the extended cavity structure is employed to confine the near-field within the radiating patch that allows to have less influence of the conducting skin and to increase the effective permittivity of the proposed antenna. To verify the effectiveness of the proposed conformal array antenna, we fabricate 2 x 2 array antenna with and without an adjacent conducting skin, and its performances, such as bore-sight gains and 2-D radiation patterns are measured in a full anechoic chamber. The results confirm that the proposed antenna structure is suitable for elements of the conformal array, which is less affected by the conducting skin of the airframe.