A simple photonic approach for the multiband phase-coded microwave generation based on a dual-drive Mach-Zehnder modulator (DDMZM) is proposed. By injecting the 5-bit barker code sequence to the bias of DDMZM, the binary phase-coded microwave signal for multiband radar application is generated. A proof-of-concept experiment is performed. The generation of phase-coded signals tuning from 1 to 9 GHz with 1 to 20 Mbit/s coding rates is verified.
A millimeter-wave optoelectronic oscillator employing self-regenerative frequency dividing and phase-locking techniques is proposed. The frequency division of millimeter-wave signal is achieved effectively via self-regenerative frequency divider breaking the frequency limitation of commercial frequency dividers. In virtue of the frequency conversion pair, the phase-locking technique is effectively utilized to stabilize the millimeter-wave optoelectronic oscillator by a commercial analog phase shifter in relative low frequency band. Finally, a 40-GHz millimeter-wave signal is generated with the single-sideband phase noise about -116 dBc/Hz at 10-kHz frequency offset. Besides, the frequency stability of the proposed millimeter-wave optoelectronic oscillator is greatly improved from 1.2×10-6 to 2.96×10-13 at 1024-s averaging time in a lab room without any thermal control.