Wide-Angle Scanning Parallel-Plate Lens in Multilayer PCB Technology

This paper presents the design of a dual-lens beamformer in multilayer PCB technology. The proposed lens is implemented in a dielectric parallel-plate waveguide, offering enhanced scanning performances along with a compact design. A combination of ray tracing and conjugate field matching is used to design the lens and feed configuration. The concept is validated by a prototype operating in the downlink K-band allocated to satellite communications (17.3 - 20.2 GHz). The shaped lens is machined from a stack of substrate layers, while the integrated feed system is realized using standard PCB techniques. The final structure produces nine stable beams over an angular sector of ±60° (±10 beamwidths) from a flared linear aperture of about 14λ. Good agreement between simulated and experimental results is obtained. The measured return loss is better than 10 dB and the port-to-port isolation greater than 17 dB over the entire frequency band. The estimated radiation efficiency of the antenna is about 75% and maximum scan losses are in the order of 2 dB.