Study On The Novel Microwave Photonic Link With High Spurious Free Dynamic Range

As compared to traditional microwave technologies,microwave photonic link?MPL?enables the transmission of microwave signals with the advantages of wide working bandwidth,low loss,light weight and immunity to electromagnetic interference.Thus,MPL has many applications including high definition cable TV distribution,radio-over-fiber and antenna remote systems.This paper presents four novel MPLs,specifically consisting of the following three parts:?1?A MPL with the capability of overcoming the dispersion-induced power fading effect.This link is based on using a dual polarization modulator and a 90°radio frequency?RF?bridge to generate optical single sideband?SSB?modulation.The third-order spurious free dynamic range?SFDR3?is largely increased by designing the angle of a linear polarizer connected to the dual polarization modulator output to eliminate the third-order intermodulation distortion?IMD3?.The experimental results demonstrate a SSB modulation MPL without dispersion-induced power fading effect and a measured SFDR3of 121.4 d B?Hz^4/5.?2?Two novel all-optical MPLs,which can overcome the bandwidth limitation problem of SFDR3.These two links are based on dual-parallel Mach-Zehnder modulators and dual-polarization modulators,respectively,and both use the self-beating IMD3 to cancel the cross-beating IMD3 to achieve high SFDR3.These two links are all optical links and do not involve any electrical radio frequency devices.Therefore,they can achieve high SFDR3over an extremely wide bandwidth.The experimental results demonstrate that these two links achieve a SFDR3 of 120.5 d B?Hz^4/5±1.6 d B over a 2-20GHz frequency range,and a SFDR3 of 124.9 d B?Hz^4/5±0.7 d B over a 2-18GHz frequency range,respectively.?3?A novel multi-octave all-optical MPL.This link is based on a dual polarization modulator.By adjusting the amplitudes of second-order distortion generated by self-beating and cross-beating respectively,to let them have equal magnitude but opposite polarity,the second-order intermodulation distortion?IMD2?around zero frequency band,and IMD2and second harmonic distortion?SHD?at double frequency band can be eliminated simultaneously,finally greatly improving the second-order spurious free dynamic range?SFDR2?.Experimental results show that a SFDR3 of 103.4 d B?Hz^2/3,a SFDR2?IMD2?of117.9 d B?Hz^3/4,and a SFDR2?SHD?of 119.1 d B?Hz^3/4 are achieved.