Digital wideband phased array calibration and beamforming using time reversal technique

A 16-channel digital wideband phased array without antenna is characterized using impulse response measurement. A chirp signal is used as probing signal. By careful chirp design, impulse response at sub-band is measured for all the channels. Spectral domain response showing dispersive phase and magnitude reveals significant imbalance among the channels. Based on time reversal technique principle, spectrum-modified time reversal impulse response is calculated. This time reversal response is applied to the chirp probing signal to verify the bandpass characteristics of the sub-band, and the waveform coherent waveform. It is also applied to the CW pilot tone to verify digital beamforming gain.