Microwave dielectric stepped-index flat lens antenna

作者:Barba Molina, Hernan; Hesselbarth, Jan 刊名:International Journal of Microwave and Wireless Technologies 上传者:胡宗洪



research paper Microwave dielectric stepped-index flat lens antenna hernan barba molina and jan hesselbarth Dielectric stepped-index flat lens antennas for operation at 12 GHz are presented. A brick-shaped dielectric with a permittivity profile optimized for focusing is sandwiched between the metallic plates of an open-ended parallel-plate waveguide. A tapered slot antenna is placed at the focal point of the dielectric lens, thereby creating antennas with high directivity of 16.8 and 15.8 dBi, respectively. In the two versions of the antenna, the parallel-plate waveguide operates in TEM-mode and in the first higher-order TE-mode, respectively. The dielectric profile is realized by appropriate mixtures of alumina ceramic powder and microscopic hollow glass spheres, realizing permittivity ranging from 1rel ? 1.31 to 1rel ? 3.24. The design of the complete antennas is based on geometrical optics followed by optimizations with a full-wave electromagnetic solver. Measurements show good agreement with simulations. Keywords: Antenna design, Modeling and measurements, Characterization of material parameters Received 14 March 2016; Revised 13 September 2016; Accepted 14 September 2016 I . I N T R O D U C T I O N Dielectric lens antennas are gaining ground in diverse application areas in microwave and millimeter-wave systems because of their acceptable size and attractive performance regarding beam shaping, sidelobe suppression, and beam steering, among others [1]. The availability of