Millimeter Wave Wideband and Low-Loss Compact Power Divider Based on Gap Waveguide: For Use in Wideband Antenna Array System

This paper presents a wideband and low-loss design of a compact power divider based on gap waveguide technology. The proposed power divider consists of two adjacent E-plane groove gap waveguide and a small ridge section to couple and equally divide the EM energy from the input E-plane groove gap waveguide to the two output ones in-phase. The simulation results show that the proposed waveguide power divider has about 40% impedance bandwidth while its size is
$0.7\lambda \times 0.6\lambda $
at the center frequency. An 8-way power divider is designed using the proposed 2-way power divider and the back-to-back configuration of the 8-way one is fabricated to investigate the performance of the proposed design. In addition, to show the application of the presented power divider, a wideband linear horn antenna array is designed and fabricated. The measured results agree well with the simulated ones and prove the excellent low-loss and wide bandwidth of the proposed power divider over the band of interest from 50-75GHz. The measured S11 of the entire 8-way power divider remains below -10 dB level, the insertion loss is around 1 dB over the band of interest. Also, the S11 of the horn array integrated with the 8-way feed network remains below -10 dB and the low sidelobes of the radiation pattern of the entire horn array indicates excellent phase and amplitude balance for the power divider over the entire bandwidth of interest.