Frequency-doubled phase-coded microwave signal generation based on cascaded modulators

A novel photonic approach to generate frequency-doubled phase-coded microwave signals with large frequency-tunable range is proposed. A dual-polarization modulator followed by a polarization controller is utilized to generate orthogonally polarized ±first-order optical sidebands. Then, a polarization modulator is employed to achieve the phase modulation of the two wavelengths. By beating the phase-modulated orthogonally polarized ±first-order optical sidebands in a balanced photodetector, a frequency-doubled phase-coded microwave signal is generated. The proposed phase-coded microwave signal generator features compact structure, high stability, and most importantly, ultra-wide operating bandwidth. By applying different coding signals, the proposed approach can also generate arbitrarily modulated signals.