Ka-Band High-Efficiency Leaky-Wave Broadside Array Antenna Based on Dielectric Image Lines

Based on a novel perturbation structure combining square hole and metal strip, a Ka-band high-efficiency dielectric image line (DIL) leaky-wave antenna array with broadside beam is proposed in this letter. Compared with the conventional periodic unit, a larger control range for the radiation capacity is realized, which is applied to the design of 20 × 8 DIL array with uniform illumination. Moreover, due to the low losses of the DIL and the waveguide feeding network, the high efficiency performance has been achieved. The measured maximum gain is 28.24 dBi at 35 GHz, which corresponds to the radiation efficiency and aperture efficiency of 77.69% and 54.39%, respectively. The stable and available broadside radiation pattern has been achieved in the frequency range of 34.4–35.4 GHz. The advantages of high efficiency and low manufacturing cost of the proposed antenna make it an excellent candidate for millimeter-wave (mm-wave) applications.