A High Gain Millimeter-Wave Circularly Polarized Fabry-Pérot Antenna Using PRS-Integrated Polarizer

This communication introduces a new structure of polarizer for generating millimeter-wave (MMW) circular polarization (CP) in a Fabry-Pérot cavity (FPC) antenna. It is the first of its kind, which integrates a 3D-printed polarizer with an inserted partially reflective surface (PRS), which contributes to a wideband CP operation with high antenna gain. The realization of CP and gain enhancement can be controlled independently by optimizing the structures of the dielectric part and the PRS of the polarizer, respectively. The proposed antenna consists of a feeding source, a substrate-integrated quasi-curve reflector, and the proposed polarizer. The feeding source and the reflector are able to be fabricated by the conventional PCB technology which is low-cost and convenient in circuitry integration. For validation, a prototype of the FPC antenna with the proposed polarizer operating at 60 GHz has been designed, fabricated, and measured. The peak gain of the antenna reaches to 20 dBic. The antenna achieves an impedance bandwidth of 20% from 54.5 to 66.7 GHz for the reflection coefficient of less than -10 dB. The axial ratio (AR) bandwidth is 12.7% from 56.5 to 64 GHz for AR ≤3 dB. The experimental results confirm a good agreement between simulation and measurement.