Holographic Design of Beam-Switchable Leaky-Wave Antenna

A holographic design of beam-switchable leaky-wave antenna (LWA) is presented. The proposed design consists of a holographic impedance modulated surface (HIMS) and control circuit. In this design, the HIMS, which carries impedance characteristics of four beams, is obtained by using a modified modulation method in the same aperture. Thus, the proposed HIMS can generate four switchable beams at a fixed frequency when it is excited by different reference waves. By controlling p-i-n diodes inserted along the feedline, four working states can be obtained. The proposed LWA is fabricated and measured. Four switchable beams with pitch angles of theta(1) theta(2) -30, theta(3) theta(4) 30 and azimuth angles of (1) 0, (2) 90, (3) 180, and (4) 270 are obtained at 18GHz. The measured peak gain of each beam is better than 17.2dBi.