Design and Implementation of Dolph Chebyshev and Zolotarev Circular Antenna Array

Abstract

Objectives: Uniform Circular Antenna arrays (UCAs) are most common in conformal antenna arrays with uniform excitation of elements. We targeted to design and synthesis UCAs with a high gain of >10 dB and a low sidelobe level of <20 dB. Methods: In this paper, the Uniform Circular Array (UCA) is presented with phase mode theory to extract the mode excitation using newly developed ARRAYTOOL. Along with phase modes, the magnitude distribution of elements is synthesized with Chebyshev and Zolotarev Polynomials whose resulting far-field patterns are desirable. Findings: It is observed that the Chebyshev and Zolotarev far-field pattern results a low sidelobe of 20 to 25 dB with fewer elements. It’s also observed that the elements spacing of more than λ/4 yields grating lobes with the visible region. This is one the design constrains for UCA with non-uniform excitation. Improvements: In comparison with uniformly excited UCAs, the Chebyshev and Zolotarev Polynomials show desirable radiation patterns with fewer elements. With sidelobe of less than 25 dB and minimum null points, the proposed microstrip array shows expected performance for RADAR system with high rotational symmetry.