Photonic Generation of Binary Phase-Coded Microwave Signals With Large Frequency Tunability Using a Dual-Parallel Mach-Zehnder Modulator

We present a photonic approach to generating binary phase-coded microwave signals with large frequency tunability using a dual-parallel Mach-Zehnder modulator (DPMZM). The DPMZM consists of a pair of sub-MZMs embedded in the two arms of a parent MZM. In our scheme, one of the sub-MZMs is fed by a sinusoidal microwave signal to be phase-coded, and the other sub-MZM is driven by a rectangular coding signal. The optical signals from the two sub-MZMs are destructively interfered by adjusting the dc bias of the parent MZM. As a result, the optical carrier is binary phase coded. A binary phase-coded microwave signal is generated by beating between the optical carrier and the sidebands. The carrier frequency of the phase-coded microwave signal is widely tunable. Phase-coded microwave signals with two different frequencies at 10 and 20 GHz are experimentally generated, respectively.