Analog variable phase shifter with active matching circuits

An analog variable phase shifter for microwave signals, said phase shifter comprising:

• a phase shift circuit having an input and output and including a first transistor having negative feedback via a variable reactance, together with active inlet and outlet matching circuits coupled to said input and output, respectively, of said phase shift circuit and providing such matching over the entire range of variation of said variable reactance, wherein the active outlet matching circuit comprises an outlet transistor having first and second transfer electrodes and an outlet control electrode and conducting between said first and second transfer electrodes in accordance with a signal at said control electrode, said control electrode being connected to an input of said outlet matching circuit to receive a signal from said first transistor, said first transfer electrode providing an output of said analog variable phase shifter and being coupled to ground via an active load having very low DC impedance and very high microwave impedance and said second transfer electrode being coupled to a reference potential.