A Low‐Profile High‐Performance Endfire Antenna Incorporating Parasitic Elements and Spoof Surface Plasmon Polaritons

ABSTRACT In this letter, a low‐profile high‐performance endfire antenna incorporating parasitic elements and spoof surface plasmon polaritons (SSPPs) is proposed. The single‐layer printed circuit board is designed based on SSPPs by adding a set of fan‐structured parasitic elements to increase the gain. The feed structure is in the form of a substrate‐integrated waveguide (SIW), which confines the electromagnetic waves to radiate forward within a fixed range. In addition, a significant increase in operating bandwidth is achieved through the addition of a V‐notch to the front end of the SIW. The SSPPs‐based endfire antenna was fabricated and experimentally evaluated, demonstrating inherently superior endfire radiation characteristics. Measurement results reveal that the antenna achieves consistent endfire radiation patterns with a peak gain of 16.4 dBi and a radiation efficiency exceeding 90% across a broad operational bandwidth spanning 17.34 to 28.12 GHz. These performance metrics suggest that the proposed antenna design is highly suitable for deployment in advanced microwave communication systems, offering a promising solution for applications requiring high gain, efficiency, and wideband functionality.