In this paper, a novel principle for vector modulator-based phaseshifters is proposed, which enables continuously adjustable phasecontrol with only one control voltage. The weighting of the vectorpaths is performed by a simple configuration of DC-coupled variableattenuators. A compact low-power-consuming L-band microwave monolithicintegrated circuit based on a commercial gallium-arsenide metal semiconductorfield-effect transistor process is presented to verify the principle.Within a phase-control range higher than 120/spl deg/, a gain of1.6/spl plusmn/0.6 dB is measured at 825 MHz. The current consumptionis 5 mA at a supply voltage of 1.8 V. To the knowledge of the authors,this is the first vector modulator-based phase shifter which requiresonly one control bias, thereby significantly decreasing the controlcomplexity.