Untilted slot array antenna at the narrow wall of the waveguide using double-ridge

Abstract

In this article a novel array antenna composed of untilted slots in the narrow wall of the double-ridge waveguide, with significantly improved cross-polarization, is presented. In the first step, suitable radiating elements for designing a linear slot array antenna were created. An untilted slot which is created the narrow wall of the double-ridge waveguide is suggested to be used as the radiating resonance slot. The concave and convex ridges are located under the untilted slots only. It is shown that the concave and convex double ridge waveguides can produce an orthogonal current distribution in the place of the slots. They are also placed successively to produce the required phase inversion between adjacent slots. The linear array consists of nine uniform resonant untilted slots in the double ridge waveguide and is designed at the frequency of 5 GHz using the normalized conductance of each radiating slot. Analyzing the simulation results shows that cross-polarization of the designed array was significantly improved, it was also found that the cross-polarization and the SLL were respectively about −65 and −16 dB. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.