High-Gain Linear Polarized Radial-Line Slot Array Antenna Based on Slow-wave PPW Structure

In this paper, a novel linear polarized radial-line slot array antenna working at 30GHz is proposed. This antenna is composed of two parts, including a metallic slot layer and the bottom slow-wave parallel-plate waveguide layer. The radial waveguide is designed with periodic bed of metallic nails in the lower plate. The slow-wave characteristic is realized since the height of nails is adjusted, and the transmission coefficient of electromagnetic wave is changed. The slot array is optimized based on the definition of equivalent problems in the waveguide region. The slots are arranged in concentric circles for linear polarization. The antenna is optimized with a peak realized gain of 22.6dBi and the radiation efficiency of 77.9% is achieved.