A Continuous Beam Steering Slotted Waveguide Antenna Using Rotating Dielectric Slabs

TL;DR

This paper presents a novel beam steering technique for a slotted waveguide antenna in the X band, using rotating dielectric slabs to achieve continuous beam direction control with high efficiency.

Contribution

It introduces a new method of beam steering by rotating dielectric slabs inside a waveguide, validated through design, simulation, and measurement of a prototype antenna.

Findings

14-degree beam steering achieved from near broadside to end-fire

Radiation efficiency ranges from 95% to 79%

Side-lobe level is -14 dB at 9.35 GHz

Abstract

The design, simulation and measurement of a beam steerable slotted waveguide antenna operating in X band are presented. The proposed beam steerable antenna consists of a standard rectangular waveguide (RWG) section with longitudinal slots in the broad wall. The beam steering in this configuration is achieved by rotating two dielectric slabs inside the waveguide and consequently changing the phase of the slots excitations. In order to confirm the usefulness of this concept, a non-resonant 20-slot waveguide array antenna with an element spacing of d = 0.58{\lambda}0 has been designed, built and measured. A 14 deg beam scanning from near broadside ({\theta} = 4 deg) toward end-fire ({\theta} = 18 deg) direction is observed. The gain varies from 18.33 dB to 19.11 dB which corresponds to the radiation efficiencies between 95% and 79%. The side-lobe level is -14 dB at the design frequency of 9.35 GHz. The simulated co-polarized realized gain closely matches the fabricated prototype patterns.