High-efficiency and wideband aperiodic array of uniformly excited slotted waveguide antennas designed through compressive sensing

A uniformly excited slotted waveguide (WG) antenna array for point-to-point communication is presented. The European Telecommunications Standards Institute class-II sidelobe level requirements are satisfied in all planes at almost all frequencies by the aperiodic arrangement of several parallel ridge WGs in the E-plane, each with a different number of equally spaced radiating slots along the H-plane. Both the optimal separation and number of slots per WG are determined through a compressive sensing approach. This results in 160 slots organized in 16 columns offering 29 dBi peak gain at Ka-band. A dedicated 16-way analog beamforming network is designed to provide the optimal nonuniform and in-phase excitation of the 16 WG channels, thereby compensating for the variable number of slots per column and the phase difference due to the E-plane aperiodicity. The measurements confirm the simulated reflection coefficient and radiation pattern characteristics, as well as the high aperture efficiency (70%-90%) over a 13.6% relative bandwidth (27.5-31.5 GHz) and <2 dB gain variation over 3.75 GHz (12.7%).