Shaped Parallel-Plate Lens for Mechanical Wide-Angle Beam Steering

This paper presents a parallel-plate lens beamformer for continuous wide-angle scanning. The design is based on a compact dual-lens system with extended scanning range and is optimized using a previously developed geometrical optics technique. Beam steering is accomplished with a mechanical feed system based on the non-contact characteristic of groove gap waveguides, offering large bandwidth, low profile, and mechanical ruggedness. The proposed concept is validated by an all-metal prototype of a 20.5-λ lens operating in the uplink Ka-band allocated to satellite communications (27.5 – 31 GHz). Good agreement is obtained between the simulated and measured performance. The measured return loss is greater than 12 dB over the entire frequency band and beyond. High scanning performances are achieved over an angular range of ±50° (±14 beamwidths), with maximum scan losses in the order of 3 dB and good pattern stability over the entire band. The proposed solution is particularly suited for next-generation satellite terminals requiring compact broadband antennas with continuous beam steering capability over a large angular range.