High-Efficiency Beamforming Leaky Wave Antenna Based on Substrate Integrated Coaxial Line for Radio-Wave Coverage in Confined Space

In this communication, a novel leaky wave antenna (LWA) based on substrate integrated coaxial line (SICL) with a composite slot is proposed to achieve a beamforming pattern and high radiation efficiency. The composite slot is constructed by weighted superposing of a series of basic cosine-shaped slots. Then, beams generated by the weighted slots are superposed in the radiation pattern. By adjusting the slot parameters and the weighting coefficients, a cosecant-distributed radiation pattern is obtained. Due to the high radiation efficiency property of the basic cosine-shaped slots, the final radiation aperture length of the proposed antenna is only
$4\lambda _{{0}}$
, and the radiation efficiency is 67.5%. The open-stopband of the LWA at broadside radiation is naturally suppressed by the composite slot structure. Thus, the angle range of beamforming can cover broadside. The simulated and measured results demonstrate that the beamforming of the proposed antenna can cover a range from 0° to 40°.