A dual-channel microwave photonic mixer with large dynamic range

A microwave photonic mixer has the advantages of large transmission bandwidth, good frequency tunability, high isolation, and anti-electromagnetic interference. For the practical application of the multi-input multi-output (MIMO) communication system, a dual-channel, large dynamic range microwave photonic mixer is proposed in this paper. By controlling the bias angle of the modulator and applying a dual-polarization coherent receiver, the quadrature modulation and demodulation of the dual-channel radio frequency (RF) signal is realized. By constructing a heterodyne polarization light source and adjusting the laser power difference, the third-order intermodulation distortion (IMD3) component in the dual-channel frequency conversion signal can be suppressed. Moreover, due to the balanced detection technology, the second-order spurious-free dynamic range (SFDR2) and the third-order spurious-free dynamic range (SFDR3) of the system are simultaneously improved. Simulation results show that this scheme can obtain local oscillator-radio frequency (LO-RF) isolation of more than 40 dB, SFDR2 of more than 98 dB.Hz(1/2), and SFDR3 of more than 115 dB.Hz(2/3). In the 16quadrature amplitude modulation (QAM) vector signal test with 450 MHz bandwidth, the adjacent channel power ratio (ACPR) of the system is up to 53 dB and the error vector amplitude (EVM) is as low as 0.3%. Finally, the error analysis of the system is also carried out.

Automated summary

This paper proposes a dual-channel, large dynamic range microwave photonic mixer for the practical application of the MIMO communication system. By controlling the bias angle and applying a dual-polarization coherent receiver, the modulation and demodulation of the dual-channel RF signal are achieved. The system achieves improved performance in terms of SFDR2 and SFDR3 due to balanced detection technology.