Patent ID: 8487799

Claim:
An RFDAC (Radio Frequency Digital to Analog Converter) for performing digital-to-analog conversion of a baseband signal, the RFDAC comprising: a multi-phase radio-frequency signal generator configured to generate at least four radio-frequency signals that are different in phase; a vector selector into which the at least four radio-frequency signals are inputted, the vector selector configured to select two radio-frequency signals from among the at least four radio-frequency signals, cause each of the two radio-frequency signals to pass through at least one transmission path, combine the two radio-frequency signals with each other, and output a combined signal; a test signal generator configured to generate and output a test signal; a multiplexer configured to select either the test signal or the baseband signal, and output the selected signal; a vector controller into which the signal selected by the multiplexer is inputted, the vector controller configured to control the vector selector based on the selected signal and at least one predetermined selection pattern, such that two radio-frequency signals among the at least four radio-frequency signals, and transmission paths of the two radio-frequency signals are selected; a detector configured to detect an output signal outputted from the vector selector; and a calibrator configured to calibrate a phase error between the two radio-frequency signals selected by the vector selector, based on an envelope of the output signal detected by the detector, when the multiplexer selects the test signal.