Ultra-wideband (UWB) coaxial-waveguide power divider using end-coupling structures

Based on end open-circuited electrical coupling structure, a novel ultra-wideband (UWB) coaxial-waveguide power divider is presented in this study. The simple equivalent circuit for the presented UWB coaxial-waveguide power divider is developed and the maximum power handling capability of the presented coaxial power divider is evaluated. A UWB four-way coaxial-waveguide power divider is designed, optimised and fabricated. The simulated and measured results of the fabricated power divider show reasonable agreement. The measured input return loss is greater than 10 dB over the entire UWB band and also greater than 17 dB from 2.7 to 9 GHz. The measured average insertion loss, amplitude imbalance, group delay and group delay imbalance are about 0.4 dB (not including the 6 dB power-dividing insertion loss), 0.45 dB, about 0.41 ns and 0.5 ns, respectively, across the UWB band.