An embodiment method for signal path measurement includes providing a first signal at a common node coupled to a plurality of signal paths that each include a respective phase rotation circuit. The method also includes providing a second signal, over a first test path, to a first node coupled to a first signal path of the plurality of signal paths, providing the second signal, over a second test path, to a second node coupled to a second signal path of the plurality of signal paths, selecting a signal path from the plurality of signal paths, transmitting, over the selected signal path, one of the first signal and the second signal, and mixing the first signal with the second signal to obtain a measurement signal of the selected signal path. A difference in phase delay between the second test path and the first test path includes a first known phase delay.