Closed-Path Toroidal-Waveguide Leaky-Wave Antenna with Directive Beam

Leaky-wave antennas (LWAs) are promising for future wireless systems that demand compactness and seamless integration. Generally, LWAs require a termination load to absorb the power remaining in their waveguide after the excitation wave has propagated beyond their radiating elements. This feature decreases the gain and efficiency of the antenna. To avoid this issue, power recycling is achieved with the innovative closed-path toroidal-waveguide based leaky-wave antenna developed in this work. Two simple coaxial feeds are employed to generate a closed-path traveling wave in the toroidal waveguide. By utilizing a circular array of L-shaped linearly polarized (LP) radiators integrated into this waveguide, the developed LWA realizes a directive beam with a realized gain of 13.2 dBi at 9.75 GHz. A measured prototype confirmed these performance characteristics.