Phase-Shifting Commutation
In the analog domain, i think like a voltage controlled phase shift would necessitate a voltage controlled impedance of some kind.  There are all kinds of funky ways this could be done for reactive components like with varactors (diodes whose reverse transfer capacitance has a high voltage dependence), saturable inductors (a varying DC voltage across the windings will induce a current which lowers the small signal inductance), etc.  Voltage controlled resistances are realized often for things like automatic gain control circuits for fixed output amplitude from variable input amplitudes, or sine oscillator stabilization.  These could be furnished with JFETs or optocouplers or blasting voltage controlled heat at RTD's or all kinds of other funky ways.  Now whether you need orthogonal control of phase and amplitude or not and how precise your open loop phase shift vs voltage characteristics need to be would dictate the direction of the design in addition to other practical matters like power, size, ranges, etc.