A Dual-Function and Dual-Band Leaky-Wave Antenna Array for the Microwave and Millimeter-Wave Applications

In this paper, a dual-band and dual-radiation mode leaky-wave antenna (LWA) with a large frequency ratio is proposed, based on the nested composite structure of spoof surface plasmon polaritons (SSPPs) transmission lines (TLs) and substrate integrated waveguide (SIW). By gradually decreasing the grooves of an odd-mode plasmonic structure, an equivalent radiating aperture is formed, which achieves a high-efficiency endfire radiation in the microwave (MW) band. By integrating mutually orthogonal ±45° inclined slots on the SIW LWA array and optimizing slot offset, circularly polarized (CP) frequency scanning beams are achieved in the millimeter wave (MMW) band. The proposed antenna features a low profile design and shared aperture characteristics, effectively addressing the different demands of communication and radar sensing in next-generation wireless systems.