A filterless reconfigurable frequency mixer based on a wideband photonic microwave phase shifter

Abstract

In this paper, a filterless reconfigurable frequency mixer based on a wideband photonic microwave phase shifter is proposed. The main device is a single PDM-DPMZM which is applied to generate a pair of orthogonally polarized CS-SSB signals. A pair of PCs are followed to introduce a tunable phase to the CS-SSB signals. By changing the detection scheme of the output optical signals and tuning the PCs, single-ended, double-balanced, I/Q, and image-reject mixer can all be achieved with the capability of full range phase shifting. And it can also perform frequency up- and down-conversion switching by adjusting the DC biases of the modulator. A simulation is carried out to demonstrate its versatility, flexibility and reconfigurability. The measured image-rejection ratio of the image rejection mixer is about 65 dB. In addition, the frequency operation range, practical applicability and feasibility are discussed. The effect of non-ideal factors or adjustable parameters, i.e., extinction ratio deterioration, DC biases drift, phase inaccuracy between I/Q path, instability or inaccuracy of the PC and LO signal power variation on system performance are also analyzed.