Improved performance of an axially-modulated conformal leaky-wave holographic antenna through using variable modulation index
Mohammad Amin Chaychi Zadeh, Nader Komjani
Abstract
In this paper, a novel method to decrease the sidelobe level (SLL) of conformal leaky-wave antennas (CLWAs) which are synthesized based on the holographic techniques is proposed. For this purpose, the holographic relation is modified by using the modulation index as a function of the spatial component corresponding to the propagation direction of the reference wave. In order to create a fascinating impedance matching between the launcher and the radiative metasurface, an initial phase is considered in the holographic formula. The designed one-dimensional (1D) sinusoidally modulated conformal antenna indicated a broadside fan beam at 18 GHz. At this frequency, about 3 dB SLL reduction was observed in the E-plane compared the traditinal holographic antenna. The measurement results indicated that the realized gain of the novel antenna at the design frequency was about 14.6dBi, and the SLL and the radiation efficiency of the antenna were −10.6 dB and 95%, respectively.