Investigations on Feeding Networks for a Liquid Crystal-Based Leaky-Wave Antenna Array

This paper investigates the feeding network for a liquid crystal-based leaky-wave antenna (LWA) array. Considering the liquid crystal technology is adopted, we select fused silica as the substrate of the feeding network. Three typical transmission lines, namely the microstrip, the substrate integrated waveguide (SIW) and the ridge gap waveguide are studied. Then three corresponding corporate feeding networks are compared and discussed in terms of transmission loss, fabrication cost, mutual coupling level and compactness. Prototypes based on the through-glass-via (TGV) and CNC micromachining technology are fabricated and measured. The feasibilities of these feeding networks are evaluated.