Dual-Band Leaky-Wave Antenna With Wide-Angle Scanning and High-Scanning-Rate Based on Double-Layer SSPP Structure

In this letter, a dual-band leaky-wave antenna (DB-LWA) based on a double-layer spoof surface plasmon polariton (DL-SSPP) structure with high scanning rate and wide-angle scanning capability is proposed. Compared to conventional single-layer spoof surface plasmon polariton (SL-SSPP) structures, the DL-SSPP structure demonstrates an enhanced field confinement capability and a lower cutoff frequency, which leads to enhanced scanning rates. Furthermore, theoretical analysis demonstrates significant advantages of the double-layer structure in designing DB-LWAs utilizing the −1st and −2nd spatial harmonics. The antenna achieves full-space scanning from −90° to +90° in the 2.3 GHz to 3.5 GHz band with an occupied bandwidth of 1.2 GHz and a remarkable scanning rate of 4.4°/%. In the 4.2 GHz to 4.95 GHz band, it realizes large-angle scanning from −90° to +40° with an occupied bandwidth of 0.75 GHz and a scanning rate of 7.9°/%. The total length of the antenna is equivalent to 3.1 free-space wavelengths with an average gain of 8.1 dBi in the low band and 9 dBi in the high band. Importantly, the design maintains a low profile, high average radiation efficiency, and structural simplicity.