Tunable ultra wideband phase shifter using Liquid Crystal Polymer

A tunable multilayer broadside-coupled phase shifter featuring ultra wideband (UWB) performance is presented. The tuning is accomplished using a DC biased liquid crystal polymer (LCP) which is used for the construction of this device. Full electromagnetic-wave simulations show that the differential phase, referenced to a suitable length of a traditional microstrip line, can be varied between 40° and 70° across the band 3.1 to 10.6 GHz by changing the biasing voltage across the LCP. The carried out simulations also show that the accomplished phase shift is accompanied by good quality insertion and return losses across the whole UWB.