Study on integrated lens for 220 GHz quasi-optical mixers

In this paper, integrated lens used in 220 GHz quasi-optical mixers are studied. The far-field patterns is investigated for a log-periodic antenna placed on hemispherical lenses with varying extension lengths. The radiation patterns of a log-periodic antenna on a silicon dielectric lens are computed using method of moments with a multilevel fast multipole method (MLFMM) technique inside the dielectric lens and electric and magnetic field integration on the spherical dielectric surface. The radiation pattern at 220 GHz shows good properties. The simulated results are presented in extension length/radius and therefore result in universal design curves for silicon lenses of different diameters. The simulated results indicate that there exists a wide range of extension lengths (ext. length/radius = 0.32 to 0.38) which result in high gain far-field patterns. For different materials used in lens, the length/radius rates are depended on the theory of synthesis.