Six-port junction with complete UWB band coverage in multilayer technology

In this work a high performance six-port junction is presented, which operates over the complete UWB 3.1 to 10.6 GHz band. A prototype has been fabricated which exhibits a return loss better than 21 dB, isolation better than 30 dB and centres with an amplitude imbalance of less than ±0.75 dB and a phase imbalance of less than ±5° across the whole UWB band. Its key element is a new slot-coupled quadrature hybrid with equalized phase velocities and discontinuity parasitics compensation, showing an amplitude imbalance between output ports of less than +0.5 dB and a phase imbalance of less than ±0.7°.