An antenna with Gaussian-beam pattern is proposed for applications to quasi-optical techniques, including integration with MMIC in millimeter- and submillimeter-wave regions. A Fabry-Perot resonator consisting of a concave spherical mirror with partially transparent surface and a plane mirror with coupling region is used to transform a guided-wave mode into Gaussian-beam TEM00 q. A Feature of Gasussian-beam pattern is evidenced by experiments at X-band.
"Gaussian-beam antenna", Proc. SPIE 2250, International Conference on Millimeter and Submillimeter Waves and Applications 1994, 22508Z (30 November 2017); doi: 10.1117/12.2303340; https://doi.org/10.1117/12.2303340