A phased array transmitter includes a plurality of vector modulators, an in-phase/quadrature (I/Q) signal generator, and a multiphase generator. The output phases of the plurality of vector modulators, and hence the direction of transmission of the phased array transmitter, are set and controlled by adjusting both the magnitude ratios of I/Q signal pairs generated by the I/Q signal generator and applied to I and Q inputs of the plurality of vector modulators and phases of a plurality of local oscillator (LO) signal phases generated by the multiphase generator and applied to LO inputs of the plurality of vector modulators. Setting and controlling the output phases of the vector modulators by varying both the magnitude ratios of the I/Q signal pairs and the phases of the LO signal phases allows the output phases of the plurality of vector modulators to be more precisely set and controlled than if the output phases were to be set and controlled only through the LO paths or only through the I/Q signal paths of the plurality of vector modulators.