This letter presents the development of a miniaturized and folded multisection quadrature hybrid for ultra-wideband (UWB) applications. For a size reduction, Stages 1, 2 and 3 are placed on the top of PCB, and Stages 5, 7 and 7 are placed on the bottom of PCB. The transition between top and bottom layers uses via transitions. Stage 4 is proposed with vertical via transitions and microstrip lines on the top and bottom sides of PCB, which is helpful for bandwidth increment and size reduction. The overall size of the proposed UWB hybrid is only 21 mm by 14 mm, and a size reduction of 50% is achieved compared with a planar multisection one. Performance comparisons are also implemented and discussed compared with a planar one.
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