Phase error correcting vector modulator for personal communications network (PCN) transceivers

A technique is reported for correcting phase errors in vector modulators for application in PCN (personal communication network) transceivers. The technique uses an AM demodulation process to extract the phase error from the output signal, and uses the capability of direct digital frequency synthesisers to predistort the phase of the inphase and quadrature components separately. The phase predistortion method can achieve accuracies of less than 0.05 degrees phase error, which can be further improved by increasing the number of bits in the synthesis.