Abstract: A modulation system for use in generating a multiphase carrier for digital communication systems which avoids phase and amplitude errors due to temperature and voltage variations inherent in balanced mixers, when used as phase modulators. In this invention, resistive divider networks are used to generate the output vector array. Each output vector thus, has an independent resistive adjustment which has no effect on the other vectors to provide individual and separately aligned phase vectors which are selected for transmission by an addressable multiplexer to provide a phase modulated carrier representing multiplex input data.