A Wideband Vertically Integrated Open-Ended SIW Circularly Polarized Antenna

A wideband vertically integrated open-ended substrate integrated waveguide (SIW) circularly polarized (CP) antenna based on stacked PCB is presented in this paper. The proposed element consists of three layers of dielectric substrates, the bottom layer is the feeding structure, the middle layer and the top layer collectively configure the radiator. Surrounding metallic via fences are used to form a hollow waveguide. Therefore, the antenna structure can be equivalent to a vertical open-ended SIW with broadside radiation. By introducing a rotationally symmetric etched metal strip, the antenna can form a wide axis-ratio (AR) bandwidth. The simulation results show that the proposed antenna impedance bandwidth is better than 40% (20-30GHz), the AR bandwidth is 35.2% (21-30GHz), and the maximum gain is 7.5dBic. The antenna has a compact structure and is easy to integrate with multi-layer PCB, making it suitable for wideband millimeter wave CP broadside radiation large-scale array applications.