A Pair of Ultra-Wideband Planar Transitions for Phase Inversion Applications

A pair of planar transitions which produce ultra-wideband (UWB) in-phase and inverted-phase signals has been developed for phase-inversion circuit applications. The two similar transitions consist of three transitional structures between microstrip line, coplanar waveguide, and parallel stripline. The proposed transitions offer design flexibility in achieving a wide range of impedances with various substrates. The implemented transitions provide low insertion loss, good impedance matching, and UWB performance from 2.1 to over 25 GHz within ±5
^°
phase difference from 180
^°
.