Microwave Photonic Link With Improved SFDR Using Two Parallel MZMs and a Polarization Beam Combiner

This article presents a linearized microwave photonic link by means of two parallel Mach-Zehnder modulators (MZMs) and a polarization beam combiner (PBC). The proposed link exhibits significant suppression in third-order nonlinearity, which results in fifth order limited performance. Experiments are conducted and measured results demonstrate 17-dB improvement in spurious-free dynamic range (SFDR), resulting in a fifth order limited SFDR of 124 dB/Hz
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. An Erbium Doped Fiber Amplifier (EDFA) and a high-power Modified Uni-Traveling Carrier (MUTC) photodiode are used to realize a link gain of 6 dB at 60 mA photocurrent for operation at 1 GHz. LTE signals with various instantaneous bandwidths centered at 1 GHz are delivered by the linearized link where spectral regrowth is dramatically suppressed.