Abstract: Phase shifters are linear one- or two-port devices for adjusting the reflection or insertion carrier phase of a band-limited signal, nominally from 0 to 2p radians. A perfect phase shifter would have: no insertion loss, a voltage standing wave ratio of 1:1, arbitrarily high power handling capability, linear phase-versus-frequency response, an arbitrarily small footprint, radiation immunity, no DC power consumption, and of course be free. Remarkably, real phase shifters can approach some of th…