Design of Arbitrarily-Extensible Multi-Band Periodical Leaky-Wave Antenna with Multiple and Large-Range Frequency-Scanning

In this communication, a design methodology for arbitrarily-extensible multi-band periodic leaky-wave antennas (LWAs) with multiple frequency-scanning in wide ranges is proposed. By implementing suitable periodic modulation, some specific slow-wave structures can transmit slow waves at lower frequencies and radiate fast waves at higher frequencies. The technique of effective control over the slow and fast wave regions is developed, enabling the design of periodic LWAs that can excite fast waves in distinct frequency bands. By integrating these LWAs, a novel antenna design with multiple frequency-scanning bands is achieved. To validate the proposed approach, a dual-band periodic LWA based on a glide-symmetric double-layer Z-shaped spoof surface plasmon polaritons (SSPPs) structure is designed, fabricated, and measured. The measured results show good agreement with the simulated ones, demonstrating large frequency-scanning ranges, good impedance matching, and stable gain performance across both bands. Building on the dual-band design, a tri-band antenna is further developed and simulated using the same methodology, and it has the potential to be extended to an arbitrary multi-band periodic LWA. Besides, another design example, based on a different slow-wave structure, is also provided to demonstrate the general applicability of this approach. Additionally, the proposed methodology also exhibits the property of independent control of each band.