A frequency-tunable binary phase-coded microwave signal generator with a tunable frequency multiplication factor

A novel frequency-tunable binary phase-coded microwave signal generator with a tunable frequency multiplication factor is proposed. The key component of the proposed system is a dual-polarization quadrature phase-shift-keying (DP-QPSK) modulator, which is driven by the microwave reference signal and the coding signal. By properly controlling the bias points of the DP-QPSK modulator and the amplitudes of the microwave reference signal and the coding signal, a fundamental, frequency-doubled, frequency-tripled or frequency-quadrupled binary phase-coded microwave signal can be generated when two orthogonally polarized optical signals at the output of the DP-QPSK modulator are combined and then detected in a photodetector. The proposed system is experimentally evaluated. A binary phase-coded microwave signal is generated at the fundamental, doubled, tripled, or quadrupled frequency. The frequency tunability and the pulse compression performance of the generated phase-coded microwave signals are also experimentally studied.