Qinggui Tan

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.

A Linearized Optical Single-Sideband Modulation Analog Microwave Photonic Link Using Dual Parallel Interferometers

Dual parallel Mach-Zehnder interferometers (MZIs) are presented to linearize the optical single-sideband (OSSB) modulation analog microwave photonic link. By using a dual-drive Mach-Zehnder modulator at the transmit side of the link, an OSSB modulation can be obtained. By exploiting different RF responses of two MZIs at the receive end, the third-order intermodulation distortion (IMD3) is well suppressed and the spurious-free dynamic range (SFDR) is enhanced. More importantly, we demonstrate fundamental-to-IMD3 ratio of 49 dB for an RF input signal power value of 10 dBm, which is 24 dB more than a conventional OSSB modulation link, and SFDR of 132 dB for a bandwidth of 1 Hz at the received optical power of 8 dBm assuming shot noise is the dominant noise contribution, which is improved approximately 20 dB.

Photonically Assisted Microwave Signal Generation Based on Two Cascaded Polarization Modulators With a Tunable Multiplication Factor

Filterless photonic generation of microwave signals with various frequency multiplication factors via series connected polarization modulators is proposed and demonstrated experimentally. Frequency octupling, sextupling, or quadrupling microwave signal can be obtained when the polarization state of the light wave, the modulation indices of the modulators, and the phase of the radio frequency (RF) driving signal are suitably set. The optical sideband suppression ratios and RF spurious suppression ratios of the generated frequency multiplication signals are measured. Besides, the frequency-tunable ability and phase noise are analyzed.

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.

Weighted Algebraic Connectivity Maximization for Optical Satellite Networks

In this paper, the topology configuration methods for heterogeneous optical satellite networks are investigated. Our objectives are to maximize weighted algebraic connectivity with respect to both network initialization and reconfiguration scenarios subject to onboard hardware constraints. The problems are not strictly convex and have been proven as NP-hard. In order to solve the problems in polynomial time, the original problems are relaxed to a convex optimization problem. Specifically, the relaxed problem is transformed to a positive semidefinite programming form, which can be solved exactly and more efficiently. Furthermore, based on the perturbation theory of matrices, we propose two greedy heuristic methods to deal with the initialization and reconfiguration case from the relaxed solutions, respectively. Simulation results show that the proposed algorithms are able to accomplish network initialization and reconfiguration correctly in the overwhelming majority of situations. The final sub-optimal solutions can also be obtained under low computational complexity.

Third-Order Inter-modulation Analysis and Simulation of Inter-Satellite Microwave Photonic Transmit Link

In this paper, we firstly researched the main parameters which effect multi-frequency inter-satellite microwave photonic transmit link and analyzed these performance influence factors. Then we gave a multi-frequency inter-satellite microwave photonic transmit link model and analyzed inter-modulation distortion. We also gave the simulation results under different DC offset. We finally gave some advice to eliminate third-order inter-modulation distortion.

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.

Design of the 110GHz high order multiplier base on IMPATT diode

As microwave technology developed, the frequency of imaging radar system working on is become higher and higher, which bring the width frequency band make a higher resolution for system. But the lack of high frequency source with a simple structure above 100GHz limits the development of high resolution imaging radar. In this paper, a 110GHz high order multiplier source is present. The source has an 18 orders and multiply efficiency is >1%, which can change a C band signal to 110GHz band with only one step. The source has a planar structure can easily integrate to radar system as a middle excitation source for TWTA (Travelling-Wave Tube Amplifier).