A Compact Circularly Polarized CRLH Leaky‐Wave Antenna for Satellite Communications

Abstract

A circularly polarized (CP) microstrip composite right/left‐handed (CRLH) leaky‐wave antenna (LWA) with wide‐angle scanning capability is proposed. The antenna is based on a microstrip transmission line that integrates patch, metallic via, and folded branches for miniaturization. The left‐handed and right‐handed parameters generated among the branches, patch, and via are balanced, thereby eliminating the OSB effect. A prototype was fabricated and tested, and the unit cell features a compact size of 0.79 λg × 0.45 λg. Measurement results indicate that the antenna achieves a wide scanning range from −68° to +34° across 9.5–12.5 GHz (27.3%). The antenna achieves a circularly polarized beam‐scanning range from −30° to +10° over 10.3–12.0 GHz (15.2%), and the maximum gain reaches 15.2 dBi with smooth variation over the operating band. These characteristics render the proposed antenna well suited for satellite communication applications.