W-Band Vector Millimeter-Wave Signal Generation Based on Phase Modulator With Photonic Frequency Quadrupling and Precoding

We experimentally demonstrate W-band vector millimeter-wave (mm-wave) signal generation and its air space transmission, from constant-modulus quadrature phase shift keying modulation to multimodulus 8-ary quadrature amplitude modulation/16-ary quadrature amplitude modulation (8QAM/16QAM) modulation, employing a photonic frequency-quadrupling scheme enabled by a single phase modulator and precoding technique. As far as we know, it is the first time to realize W-band 8QAM/16QAM vector mm-wave signal generation based on a single phase modulator with photonic frequency multiplication. We also investigate by numerical simulation and experiment the effect of the radio-frequency (RF) driving peak-to-peak voltage of the phase modulator on the performance of the generated vector mm-wave signal, and find that there exists an optimal RF driving peak-to-peak voltage for the best performance of the generated vector mm-wave signal, which agrees well with our theoretical analysis.