On the performance of a linearized dual parallel Mach–Zehnder electro-optic modulator

Abstract

Abstract-The performance of a dual parallel differential Mach-Zehnder modulator broadband linearization architecture is analysed. This study provides experimental and analytical results showing an enhancement up to 20 dB in the 3rd-order intermodulation distortion factor at 5 GHz using RF and optical asymmetrical feeding factors.Keywords-optical fibre communications, fibre radio, modulator, linearisation techniques, microwave photonics IntroductionOver the last decade, a number of bandwidth hungry applications and services have appeared, e.g., HD streaming, mobile broadband and online gaming. To address this high bandwidth demand, ubiquitous and high data-rate access technologies have emerged based on a range of wireless, fibre and optical-wireless technologies, e.g. radio-over-fibre (RoF). However, RoF systems performance, e.g. dynamic range, is limited by the nonlinear response of the optical transmitters, e.g. electro-optical modulator (EOM). EOM exhibit an inherent non-linear behaviour, which is reflected in a non-linear transfer function due to different factors, e.g., bias wavelength and polarization dependence or environmental factors [1]. Therefore, this

LTE Signal Transmission Over a Linearized Analog Photonic Link With High Fidelity

“…To summarize, most of the existing modulator linearization techniques need an additional path and asymmetric feed to generate equal and opposite IMD3 signals. The asymmetric feed can be realized using RF attenuators/amplifiers, optical attenuators/amplifiers [19], wavelength dependent Vπ [15], or polarization dependent Vπ [17], [20]. The π-phase difference between the main and secondary channels can be realized by using an additional phase modulator [6], [12], [13], [21], biasing two MZMs at opposite quadratures, adding a 180°RF hybrid coupler [15], using push-pull modulation [16], using lower and upper sideband modulation assisted by an FBG [18], or employing RF phase shifters [22].…”

Highly linear W-band receiver front-end based on higher-order optical sideband processing

“…The thirdorder intermodulation distortion (IMD3) as the main nonlinear distortion factor limits the SFDR, since it is closest to fundamental signals and cannot be filtered out [9] . In past decades, many compensation techniques have been presented to suppress the IMD3 and enhance the SFDR, which include electrical and optical compensation [10][11][12][13][14][15][16][17][18][19][20][21][22][23] . Although digital linearization techniques like pre-distortion, and digital post-processing dependent on digital signal processing (DSP) can achieve a recorded SFDR, the limited bandwidth of electric c ircuits will restrict high-frequency application [10][11][12] .…”

“…Although digital linearization techniques like pre-distortion, and digital post-processing dependent on digital signal processing (DSP) can achieve a recorded SFDR, the limited bandwidth of electric c ircuits will restrict high-frequency application [10][11][12] . In an optical domain, many approaches are achieved by specially designed modulators, such as a singledrive dual-parallel MZM (DPMZM) [13] , a dual-drive DPMZM [14,15] , a mixed polarization dual-electrode MZM (DEMZM) [16] , a polarization modulator (PolM) [17] , or two DPMZMs in parallel [18] . By using these modulators, two or more sources of the IMD3 are generated to directly cancel each other.…”