Photonic multiple frequency measurement with phase identification based on frequency conversion

In this paper, a very simple multiple frequency and phase identification structure is proposed and demonstrated. The main device is a dual-parallel Mach–Zehnder modulator (DPMZM). Adjusting the DC voltages to make this modulator works at the minimum transmission point (MITP) and satisfy the power cancellation condition. Then sweeping the LO signal frequency, the frequency and phase information of the received unknown microwave signals are extracted out by the created mapping between the total output power of the system and the LO frequency. The simulation results show that the frequency measurement range can be larger than 40 GHz, the accuracy is about 4 MHz, the resolution is better than 10 MHz. In addition, it also possesses the phase identification ability with the range from 0 to π, and the accuracy can up to 0.03 rad. This approach supports an effective way to implement the multiple-frequency measurement and phase identification. It has the potential to be integrated into a receiver.