A Low-Profile High-Performance Endfire Antenna Based on Spoof Surface Plasmon Polaritons

A low-profile high-performance endfire antenna is proposed based on spoof surface plasmon polaritons (SSPPs). The feeding structure can stimulate odd mode on the SSPPs strips by using substrate integrated waveguide (SIW). A triangle-shaped SSPP radiator is proposed to produce endfire radiation, which acts as an array of small current sources. The gain and sidelobe level of the antenna are improved by adding a flared slot and tapered SSPP part, while bandwidth is increased by using rectangular slots in the SIW. The proposed SSPP endfire antenna is fabricated and tested, which exhibited excellent endfire radiation performance. The measurement results illustrate that the stable endfire radiation with a maximum realized gain of 15.2 dB and high radiation efficiency of about 90% is achieved in the wide frequency band of 16–22.7 GHz. This endfire antenna can be a good candidate for microwave communication applications.