A Planar Dual-Band and Dual-Sense Circularly Polarized Microstrip Patch Leaky-Wave Antenna

This letter presents a simple single-layered dual-band circularly polarized microstrip patch leaky-wave antenna (LWA). The proposed design consists of two linear circular patch arrays that are coupled to a 50 Ω microstrip line. While having high gain, the rotating sense in each band is opposite to each other, which makes the antenna concept well-suited for the uplink and downlink satellite communication. For demonstration, an antenna has been designed to operate at 5.0 and 8.0 GHz. It is noted that the concept can be easily adapted to other frequencies. With a total length of 2.89λ
₀
(λ
₀
is the free-space wavelength at 5.0 GHz), the antenna prototype achieves a satisfactory measured axial ratio (AR) with peak realized gains of approximately 12 and 13.6 dBi at 5.0 and 8.0 GHz, respectively.