Millimeter-wave Low-profile Spoof Surface Plasmon Polaritons Endfire Antenna Using Traveling-wave Feeding Mechanism

A novel endfire antenna utilizing spoof surface plasmon polaritons (SSPP) and a traveling-wave feeding mechanism is introduced. The proposed endfire antenna operates in the millimeter-wave (mmW) band. The placement of a Vivaldi antenna at the front end of the SSPP endfire antenna allows for the efficient transmission of surface waves and the generation of an end-fire beam. The electromagnetic waves are coupled from the travelingwave feeding mechanism to the slot located between the Vivaldi antenna and the SSPP endfire antenna. Furthermore, we conducted a comparison between the effects of a standing-wave feeding mechanism and a traveling-wave feeding mechanism on the transmission performance and radiation pattern of the designed endfire antennas. The numerical analysis demonstrates that employing a traveling-wave feeding mechanism leads to a reduction of 63% in impedance bandwidth, while concurrently increasing the gain by 0.42dB. The ultimate configured antenna aperture measures 0.21λ
0
× 0.02λ
0
, showcasing its low-profile attributes.