SIR Stub‐Based Dual‐Band Leaky Wave Antenna for Vehicular Communication

ABSTRACT

This paper presents a compact dual‐band leaky‐wave antenna (LWA) based on a periodically loaded microstrip line incorporating two non‐identical stepped‐impedance resonator (SIR) stubs per unit cell. The dual SIR configuration excites two independent leaky modes within the same aperture, enabling frequency‐controlled beam scanning in both sub‐6 GHz and upper 7 GHz ranges, suitable for V2X and future 6G applications, respectively. The designed structure exhibits continuous beam steering from approximately to in the lower band (5.6–5.9 GHz) and from to in the upper band (7.1–7.7 GHz). The antenna is realized on an FR‐4 substrate (), achieving measured impedance bandwidths of and in the two bands, with peak realized gains of 3.23 and 3.03 dBi, respectively. A periodic dispersion analysis and an equivalent lumped‐element model are developed to verify the leaky‐wave mechanism. Simulated and measured results show good agreement, confirming that the dual SIR loading within a single aperture can effectively produce distinct leaky‐wave radiation bands while maintaining compactness and low fabrication cost.