Dual-Beam Frequency-Scanning Antenna Based on SSPP for Full-Space Continuous Scanning

In this article, a dual-beam frequency-scanning antenna based on spoof surface plasmon polariton (SSPP) is designed for continuous scanning in full space. The antenna is composed of a double-layer composite single-sided (DL-CSS) SSPP transmission line (TL) and asymmetric radiation patches. The DL-CSS SSPP element has stronger dispersion characteristics and well-separated dispersion curves, facilitating designing the frequency-scanning antenna with dual-beam, ultrawide angle, and high scanning rate. The asymmetric radiation patches consist of an elliptic patch array and a rectangular patch array with different modulation periods, effectively improving the open-stopband effect through beam synthesis. Simulation and measurement results show that the dual-beam frequency-scanning antenna can realize 360° full coverage scanning in the whole space without a dead angle. The operating frequency band is 6.79–8.69 GHz, the relative bandwidth is 24.5%, and the scanning rate is 7.35°/%. The average gain is 9.98 dBi and the maximum gain is 12.38 dBi. Furthermore, the overall radiation efficiency is more than 50%, and the average radiation efficiency is 68.99%. Thus, the designed antenna not only greatly broadens the scanning range and raises the scanning rate but also improves the open-stopband effect of broadside radiation. Meanwhile, its full-space continuous scanning capability has a broad application prospect in autonomous vehicles and intelligent transportation systems, radar systems, wireless communication network optimization, radio signal intelligence, spectrum monitoring and management, disaster recovery and emergency communications, radio astronomy, and so on.