Performance-Enhanced and Symmetric Full-Space Scanning End-Switched CRLH LWA

An end-switched composite right/left-handed (CRLH) electronically scanned leaky-wave antenna (eLWA) is presented. The input signal is routed to either end of the CRLH eLWA via a switch, with each end providing half-space scanning (-90° ≤ θ ≤ 0°) . The end-switching scheme, which is applicable to any two-port LWA, enables full-space coverage using any half-space scanning only LWA. Compared to a conventional single-ended CRLH eLWA, which scans the full-space requiring a complex design, large capacitance values, and tuning range, the end-switched scheme simplifies the design and relaxes the constraints on the varactors, which lowers their cost. The conventional CRLH eLWA also suffers from a large scanning loss due to its large scanning range and from low efficiency due to its requirement for large capacitance values, which exhibit high loss. The end-switched CRLH eLWA reduces the scanning loss due to its smaller scanning range, while improving the efficiency due to its low capacitance values.