2021 Volume 18 Issue 1 Pages 20200411
This paper presents a comparison of optical leaky-waveguide antennas, i.e., grating waveguide (GWG), waffle waveguide (WWG), and waffle-iron waveguide (WIWG), using both simulations and measurements. WIWG radiates a narrow beam that is tilted by sweeping the incident wavelength, and it possesses a higher antenna gain than GWG and WWG under the same fabrication condition. The reason is due to a slight difference in the effective index along the longitudinal sections, which provides a large aperture size for high antenna gain. We simulate the antenna characteristics and experimentally confirm the high antenna gain.