A Butterfly Space Harmonic Leaky-Wave Antenna Based on Substrate Integrated Waveguide

A substrate integrated waveguide leaky-wave antenna using butterfly transverse slots is proposed. This antenna operates in the first negative floquet mode which is a space harmonic wave. The radiation frequency can be by modified the distance of slots and the highest gain of antenna can be achieved 15dB. The proposed antenna has a butterflylike configuration with length periodic gradient and can solve the problem of the space harmonic leaky wave antenna which has a low radiation gain in the low-frequency stage. This design increases the radiation in the low-frequency stage from 4dBi to 10dBi, meanwhile, achieves wider beam-scanning angel with more narrow frequency bandwidth. The simulated data have been compared with measurement results and showed good consistency.