Small size dielectric image linebased leaky wave antenna with 3 H-shaped patches

A small size dielectric image line (DIL)-based leaky wave antenna (LWA) is proposed in this paper. Three H-shaped patches as radiation elements are periodically printed on top surface of DIL, which generates infinite higher order space harmonics, and the proposed antenna works at the first order mode. The H-shaped unit cell has high attenuation constant, which leads to power leaking quickly. So high radiation efficiency can be realized with only 3 unit cells. Simultaneously, the open stopband (OSB) is suppressed using H-shaped unit cells to get high efficiency at broadside. The working principle of the proposed antenna is analyzed, and the numerical results validate the theory analysis. Over the operating band (11:5 ~ 14:6 GHz), the proposed antenna covers 71° from -41° to 30° (including the broadside) with stable gain (8:7 dBi ~ 10:6 dBi) varying less than 2 dBi. A prototype is fabricated and measured, which has good agreement with simulation results.