Millimeter-Wave Filtenna Based on Double-Grating Rectangular Waveguide and Spoof Surface Plasmon Polaritons

In this paper, an all-metal millimeter-wave (mm-Wave) flltenna using double-grating rectangular waveguide (DGRWG) and spoof surface plasmon polaritons (SSPPs) is proposed. The DG-RWG comprises ten rows of gratings positioned on both sides of a rectangular waveguide. The SSPPs structure consists of three portions which are gradient transition, SSPPs transmission line, and sinusoidally-modulated SSPPs. The DG-RWG provides a lower cut-off frequency, whereas the SSPPs provides an upper cut-off frequency. The simulated impedance bandwidth is within the range of 29.8 GHz to 37.2 GHz. In the passband, the main beam is directed to be around 75° and the peak gain is 13.1 dBi. Outside the passband, the gain exhibits a decay rate of over 13 dB/GHz.