Ka-Band Low-Sidelobe-Level Slot Array Leaky-Wave Antenna Based on Substrate Integrated Nonradiative Dielectric Waveguide

This letter presents a leaky-wave antenna array in the substrate integrated nonradiative dielectric (SINRD) waveguide technology. Several radiating slots are etched on the copper foil of the SINRD guide and placed with opposing tilt angles to achieve a compact configuration. After investigating the characteristic of the complex propagation constant of an SINRD guide with slots, the low sidelobe level (SLL) of a leaky-wave antenna can be synthesized. Besides, this kind of antenna can be fabricated directly on the printed circuit board substrate, which means that it can be easily integrated with other kinds of planar circuits in the millimeter-wave band. As an example, a Ka-band prototype is designed and experimented, which has -18.1 dB SLL and 12.7 dBi gain at 29.4 GHz.