Linear reflection phase shifter with optimised varactor gamma

It is difficult to realise linear microwave reflection phase shifters at frequencies higher than 3 GHz using abrupt junction varactor diodes, since the diode parasitic package capacitance begins to dramatically affect the phase shift linearity. The use of hyperabrupt junction varactor diodes can significantly improve the phase shift linearity at these frequencies. A circuit and the simulation results for a linear reflection phase shifter implementation using hyperabrupt junction varactor diodes at 3.6 GHz are presented