Ridged Meandered Waveguides for 3-D Routing and Phase Delay Control and Its Application to Discrete Lenses

In this article, an innovative procedure to design ridged meandered waveguides (RMWs) is introduced. By modulating the meandered centerline of a waveguide connecting two fixed points, new degrees of freedom (DoFs) to control the phase delay are obtained. RMWs represent a good compromise between coaxial cables, which feature broadband operation and can be easily bended still introducing high losses and conventional waveguides, which are characterized by low losses but also narrow operational bandwidth. RMWs are especially well-suited for isophase lattice expanders that can be used in beamforming networks (BFNs), phased arrays, or discrete 3-D lens antennas. The article describes a methodology to design meandered waveguides (MWs), which is verified both analytically and experimentally through the synthesis, fabrication, and test of a discrete 3-D lens antenna in the Ka-band (27.5–30 GHz) made using additive manufacturing (AM).