Single-Layer Large Frequency-Ratio Dual-Band Vivaldi-Leaky-Wave Embedded Antenna for Coverage Enhancement

Abstract

In this letter, a single-layer shared-aperture Vivaldi-leaky-wave embedded antenna (V-LWEA) for coverage enhancement is presented. To mitigate the open-stopband effect and increase leakage rate in high-band (HB), periodic elliptical-slot unit cells are introduced, which facilitate single-port excitation without bulky absorptive terminations. Experimental results demonstrate that the proposed V-LWEA achieves a 134.6% impedance fractional bandwidth (IFBW) from 1.72 GHz to 8.8 GHz with a gain of 2.36 dBi to 8.49 dBi in low band (LB), and a 38.6% IFBW from 25.7 GHz to 38 GHz with a gain of 10.35 dBi to 14.14 dBi in HB. The antenna exhibits a fixed endfire beam in LB, whereas it provides bidirectional single-beam frequency-scanning radiation, including ±broadside direction at millimeter-wave frequencies. Besides, the antenna features a large frequency ratio of 6.06. With the advantages of compact size, wide bandwidth, and spatially differentiated coverage, the V-LWEA is a promising candidate for integrated sensing and communication platforms.