Zhongbo Zhu

A Linearization Analog Photonic Link With High Third-Order Intermodulation Distortion Suppression Based on Dual-Parallel Mach–Zehnder Modulator

A scheme to realize a high linear analog photonic link based on a dual-parallel Mach-Zehnder modulator (DPMZM) is proposed and demonstrated in this paper. By using only two electrical phase shifters with π phase shift and optimizing the biases of the DPMZM, the third-order intermodulation distortion (IMD3) is completely eliminated by taking all the sidebands in the optical spectrum that produce IMD3 into consideration in theory. Without digital linearization, other optical processers, and symmetrical singlesideband modulation, optical carrier suppression (OCS) is achieved in one of the submodulators of DPMZM, which guarantees the effectiveness of information transmission. Quadrature modulation is achieved in the other submodulator of DPMZM, and the electrical signals on the two electrodes are the same, which result in a simple operation. The simulated results show that IMD3 is completely suppressed when the sinusoidal electrical signals have two tones, such as 11.9 and 12 GHz, and IMD3 is lower than the noise floor at the -120 dBm level. The simulated results show that IMD3 is lower than the noise floor with -120 dBm level, and the simulated results agree well with the theoretical prediction. In addition, IMD3 suppression of approximately 45 dB is experimentally demonstrated in this paper, and the spurious-free dynamic range is improved by 11.2 dB . Hz2/3. The scheme could simplify the design of a high linearized analog photonic link and make it stable.

Influence of Power Distribution on Performance of Intermodulation Distortion Suppression

A linearized analog photonic link based on a dual parallel Mach-Zehnder modulator (MZM) and an unsymmetrical power divider is proposed and demonstrated. By adjusting power distribution ratio of radio frequency signals, the third-order intermodulation distortion (IMD3) of two submodulators balances each other. Influence of power distribution ratio on the performance of IMD3 suppression is evaluated in experiment. When the power distribution ratio is 0.1, IMD3 suppression can achieve to ~ 62.1 dB according to the experimental results. Spurious-free dynamic range is improved by 23 dB in a 1-Hz bandwidth comparing with the scheme based on a single MZM. Experiment results are in good agreement with the theoretical analysis.

A time-domain compensation model with high IMD3 suppression for microwave photonic links

A time-domain model with high third-order inter-modulation distortion (IMD3) suppression is presented and simulated in the paper. The model can effectively compensate nonlinear distortion effects of microwave photonic links based on dual parallel Mach-Zehnder modulator (DPMZM) with double RF signals. The model results in simple exact expression for harmonic and inter-modulation components at the output of the diode detector (PD), which can be applied to the realization of microwave photonic links with high IMD3 suppression. The nonideal factors such as the electrical phase shift error of Τ phase shifter, amplitudes of the electrical signals applied to the electrodes of DPMZM offset to ideal values, and the half-wave voltages of sub-modulators offset to the ideal values are studied in detail. Numerical results for IMD3 suppression are well matched with the analysis ones.

Design of Multi-Channel Microwave Photonic method for earth observation satellite

Summary form only given. Fiber optics, which has some advantages such as electromagnetic interference immunity, high bandwidth, low mass and mechanical flexibility, are used in the payload of Soil Moisture, Ocean Salinity (SMOS). But in the SMOS, it needs to distribute the Local Oscillator, the calibration microwave signal and the clock reference to the 72 microwave receivers. This paper demonstrates a possible microwave photonic evolution method (MPEM), which can directly transmit the Y-shaped antennas received microwave signals to the Control and Correlator unit (CCU) parallelly by microwave photonic links. The MPEM is shown in Fig. 1. The optical harness mainly consists of E/O, O/E and fiber links. The received microwave signals are analog converted to optical signal by E/O, and then transmitted to the CUU parallelly by 144 microwave photonic links. At the CUU, the received microwave signals are generated by O/E. Compared with the existing SMOS optical link, it does not need to distribute the Local Oscillator, the calibration microwave signal and the clock reference to the 72 microwave receivers. The linearity and noise figure of microwave photonic links are measured with single frequency signal resource and noise source. The measured results show that the linearity of the microwave photonic links with noise source is 0.999772689 (show in Fig. 2), which suits to the performance requirements of SMOS. And this Multi-Channel Microwave Photonic Scheme can be used to other satellite payload with arrayed microwave signal receivers.

A high linearized microwave photonic link under dual-tone modulation

In this paper, a schematic of high linearized microwave photonic link under dual-tone modulation is proposed and analyzed. On the basis of dual parallel Mach-Zender modulator (DPMZM), by utilizing only two simple and mature electrical phase shifters, and by optimizing the biases of the DPMZM, third-order inter-modulation distortion (IMD3) introduced by all optical sidebands is eliminated completely in theory. Besides, the corresponding simulation setup and experimental setup for testing the linearization of microwave photonic link are built, and parameters such as third-order inter-modulation distortion (IMD3) suppression, spurious-free dynamic range (SFDR) are simulated and demonstrated in detail. Test results are in good accordance with the theoretical prediction.

A Highly Linearized Photonic Mixer Based on Unsymmetrical Power Dividing for RoF System

In this paper, a highly linearized photonic mixer is proposed and demonstrated for Radio over Fiber (RoF) system. This scheme is based on an Intensity modulator (IM) and a dual parallel Mach--Zehnder modulator (DPMZM) in series. By adjusting the unsymmetrical power dividing rate and optimizing biases of the DPMZM, the third-order intermodulation distortion (IMD3) is suppressed. A proof-of-concept experimental verification is carried out. 10GHz RF signal is down-converted to2GHz. When the power dividing ratio is 0.1, IMD3 suppression of 33 dB is experimentally demonstrated. The spurious-free dynamic range (SFDR) is improved by 21.4 dB and reaches to 116 dB.Hz4/5 as comparing with the conventional photonic mixer.

Study and demonstration of broadband microwave photonic performance for telecommunication satellite

In this paper, an architecture of broadband telecommunication satellite payload is introduced. On the basis of photonic technology, The payload can cope with usual requirements such as receiving and re-transmitting of inhomogeneous signals. Besides, the corresponding system for testing performance of microwave photonic of wideband telecommunication satellite is built, and parameters such as noise figure (NF), system linear property and the transmission property of the broadband signals are analyzed and demonstrated in detail. Test results are in good accordance with the theoretical prediction.