A right-handed circularly polarized array antenna based on gap waveguide technology at 35 GHz

In this article, the authors have proposed a right-handed circularly-polarized array antenna with gap waveguide (GWG) distribution network at 35 GHz. By using GWG technology, the strict electrical contact of different layers is not required so that the expensive vacuum welding or the diffusion bonding technology can be avoided. The entire geometry consists of the top radiation layer and two distribution network layers on the bottom. The aperture shape of the top radiation layer has been designed as a hexagon in order to generate the circular-polarized electromagnetic waves. The final measurement results show that the reflection coefficient of the whole array antenna is below −10 dB with 8.45% bandwidth where the axial ratio is less than 2 dB. The antenna efficiency is higher than 70% over the whole operating frequency band, and the corresponding antenna gain is higher than 30.8 dBi.