Ultra-wideband 12-way coaxial waveguide power divider with rotated electric field mode

A novel ultra-wideband (UWB) multi-way oversized coaxial-waveguide power divider with rotated electric field mode is presented. To change the direction of the output ports of the power divider from radial to axial, the electric field orientation within the oversized coaxial waveguide is rotated from the radial to axial by using a stepped inner conductor in oversized coaxial waveguide. The transmission-line theory is used to analyse this proposed power divider and approximate equivalent circuit model is developed to investigate the characteristics and design of the coaxial power divider. A UWB 12-way coaxial waveguide power divider is developed with excellent agreement between simulated and measured results. The return loss is greater than 10 dB over the entire UWB band and also greater than 15 dB from 3.2 to 10.3 GHz. The average insertion loss, amplitude imbalance, phase imbalance and group delay are around 11.1 dB, ±0.5 dB, ±4° and around 0.4 ns, respectively, across the UWB band.