Miniaturized low-profile end-fire antenna based on spoof surface plasmon polaritons

A compact low-profile end-fire antenna based on spoof surface plasmon polaritons (SSPPs) has been proposed. At the junction, where the antenna connects to the transmission line, there is a 180 degree balun structure for achieving end-fire radiation. Subsequently, two symmetrical transmission lines are introduced, with two parasitic patches loaded on the transmission lines for optimizing the S-parameters of the antenna. The addition of the balun structure ensures that the SSPP units operate as dipoles within the frequency band. Furthermore, the dispersion parameters of the SSPP units are simulated and analysed. The Hansen-Woodyard condition is applied to derive the maximum end-fire gain at the terminal. The results show that the end-fire antenna operates in the frequency range of 18–20 GHz, with an average gain of 10.1 dBi and a peak gain of 10.6 dBi. The proposed end-fire antenna is miniaturized and low-profile compared to conventional antennas.The simulation and measurement results are in good agreement within the operating frequency band, thus showing that the proposed design has a great potential for future wireless communication applications.