Transmission phase measurement and calibration method utilizing higher-order frequency bins

摘要

A circuit includes a transmission channel that outputs a continuous-wave signal based on a reference signal, a transmit monitoring signal path that couples out a portion of the transmit signal as a monitoring signal, a test phase shifter that receives the reference signal and generates a phase-shifted signal based on a sequence of phase offsets applied to the reference signal, a phase mixer that mixes the phase-shifted signal and the monitoring signal to generate a mixer output signal including a plurality of direct current (DC) values, an analog-to-digital converter that samples the mixer output signal in order to provide a sequence of DC values; and a monitor circuit that applies a discrete Fourier transform (DFT) to the sequence of DC values to generate a plurality of DFT bins with corresponding DFT bin values, and generate compensated phase information of the transmission channel using at least two DFT bin values.