Theoretical Investigations on CPW-Fed Single and Dual-Polarized Slot Radiators Using Schelkunoff’s Biconical Antenna Analysis

Abstract

This article presents a closed-form analysis of CPW-fed slot dipole structures with the help of Schelkunoff’s biconical antenna analysis technique and Babinet’s principle. Input characteristics of CPW-fed slot dipole antennas are investigated, and closed-form expressions are derived for the purpose. The feed-gap inherently generated in CPW-fed antenna configurations is accounted for in the expressions, and the analysis of Schelkunoff is modified to address the same. Single-polarized structures can be orthogonally placed to generate dual-polarized characteristics – this notion is utilized to extend the proposed structure of a single CPW-fed slot dipole radiator towards a dual-polarized configuration. The proposed theoretical expressions are further validated for the dual-polarized geometry, and good agreement is observed in concerned theoretical and measured results. The simplicity of the proposed expressions is evident as they entirely consist of Sine and Cosine integrals and facilitate faster computation. Schelkunoff’s Biconical Antenna method is rarely used for solving a planar slot radiator problem which justifies the novelty of this article. The present work also, for the first time – modifies the method of Schelkunoff to further account for the inherently generated feed-gap in CPW-fed planar monopole or dipole configurations.