Generating and Steering of Quasi-nondiffraction Beam by Substrate Integrated Waveguide Slot Array Antenna

Abstract

A millimeter-wave single layer substrate integrated waveguide (SIW) slot array is presented in this paper, which is designed to generate and steer the quasi-nondiffraction beam. In most of the existing nondiffraction beam launchers, the required phase and amplitude distribution are achieved with the central feeding radial topology. As a result, the propagating direction of the previous quasi- nondiffraction beam is usually along the broadside direction and cannot be steerable. Here, a transverse SIW Leaky-wave slot array is proposed to generate the quasi-nondiffraction beam. The slot distribution is modulated to generate the holographic phase for changing the wavefront of the incident wave to synthesize a near-field focusing antenna with a controlled depth of field. Besides, a passive beamformer is investigated and integrated with the slot array in a whole substrate. Each single leaky-wave slot array is designed with the tapered radiation distribution, working together with the tapered passive beamformer to generate the desired tapered amplitude distribution in the whole array aperture. The quasi-nondiffraction beam frequency scanning capacity of the leaky-wave SIW slot array is investigated and implemented. This type of antenna has a good prospect in near-field fast scanning applications.