Photonic Generation of High Fidelity RF Sources for Mobile Communications

A novel technique for generating RF sources for mobile communications based on dual Mach–Zehnder modulators and high-power charge-compensated modified unitraveling carrier (CC-MUTC) photodiodes is presented. A system model is developed and used to establish and mitigate nonlinearities attributed to its constituent components, i.e., waveform generators, amplifiers, modulators, and photodiodes. In particular, digital predistortion is used to improve source linearity. Extensive experiments are conducted to characterize the proposed system, using a commercial 5 MHz local thermal equilibrium signal. Optimal results are achieved with a CC-MUTC photodiode to attain an RF power greater than 12.5 dBm and an adjacent channel leakage ratio lower than −63.5 dBc.

[1]  Steven K. Korotky,et al.  Dual Parallel Modulation Schemes for Low-Distortion Analog Optical Transmission , 1990, IEEE J. Sel. Areas Commun..

[2]  K. Kikushima,et al.  Distortion due to gain tilt of erbium-doped fiber amplifiers , 1991, IEEE Photonics Technology Letters.

[3]  B. Jalali,et al.  Electronic linearization and bias control for externally modulated fiber optic link , 2000, International Topical Meeting on Microwave Photonics MWP 2000 (Cat. No.00EX430).

[4]  Jungsang Kim,et al.  Digital predistortion of wideband signals based on power amplifier model with memory , 2001 .

[5]  A. Beling,et al.  Characterization and Optimization of InGaAs/InP Photodiodes with High Saturation Current , 2007, 2007 International Conference on Numerical Simulation of Optoelectronic Devices.

[6]  Dayong Zhou,et al.  Novel Adaptive Nonlinear Predistorters Based on the Direct Learning Algorithm , 2007, IEEE Transactions on Signal Processing.

[7]  K. Williams,et al.  Photodetector Nonlinearities Due to Voltage-Dependent Responsivity , 2009, IEEE Photonics Technology Letters.

[8]  Voltage-dependent nonlinearities in uni-traveling carrier directional coupled photodiodes , 2010, 2010 IEEE International Topical Meeting on Microwave Photonics.

[9]  Kun Xu,et al.  Digital linearization technique for IMD3 suppression in intensity-modulated analog optical links , 2011, 2011 International Topical Meeting on Microwave Photonics jointly held with the 2011 Asia-Pacific Microwave Photonics Conference.

[10]  J. Campbell,et al.  Characterizing and Modeling Nonlinear Intermodulation Distortions in Modified Uni-Traveling Carrier Photodiodes , 2011, IEEE Journal of Quantum Electronics.

[11]  Jie Zhou,et al.  Digital Predistortion for Concurrent Dual-Band Transmitters Using 2-D Modified Memory Polynomials , 2013, IEEE Transactions on Microwave Theory and Techniques.

[12]  Photonic downconverting link with digital linearization , 2015, 2015 IEEE MTT-S International Microwave Symposium.

[13]  Xinwan Li,et al.  Linearity Characterization of a Dual–Parallel Silicon Mach–Zehnder Modulator , 2016, IEEE Photonics Journal.

[14]  Dennis W. Prather,et al.  Optically Upconverted, Spatially Coherent Phased-Array-Antenna Feed Networks for Beam-Space MIMO in 5G Cellular Communications , 2017, IEEE Transactions on Antennas and Propagation.