Design and realization of 3 dB offset coupled stripline coupler in 6 - 18 GHz

In this paper, an ultra-wideband (UWB) 3 dB coupler is designed. It is based on the offset coupled stripline technique with a symmetric structure of the multi-section coupler. Utilization of capacitive compensation technology. It achieves a working bandwidth covering 6 - 18 GHz. The experimental results of this coupler show that return loss of all ports is less than -10 dB, and the relative phase difference is 90 ± 6˚. The designed coupler was simulated, processed and measured. The measured results are found to be essentially consistent with the simulated results.