title: Digital linearization of multi-carrier RF link with photonic bandpass sampling.
abstract: Due to the capacity in simultaneously down-converting and receiving ultra-wideband, multi-carrier radio frequency (RF) or microwave signals, the photonic bandpass sampling has found more and more applications in multi-carrier communication, frequency-agile coherent radar, compressive sensing, etc. The nonlinear transfer during the electronics-to-optics conversion results in distortions, which are bandpass sampled and frequency-folded within the first Nyquist zone, together with the target signals. Because of the multi-octave-span operation, all nonlinearities must be considered besides the usually-concerned third-order inter-modulation distortion (IMD3). We show theoretically that a photonic bandpass sampling link is equivalent to a baseband digital nonlinear link, and then propose a corresponding linearization scheme for the output signal. Such digital linearization is capable of suppressing all types of distortions. Both numerical and experimental examples are demonstrated, where all of the 3rd-order nonlinearities, including the internal and external IMD3, the cross modulation, and 3rd-order harmonics, are well eliminated.
authors.forename: Yitang
authors.initials: Y
authors.lastname: Dai
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liang
authors.forename: Feifei
authors.initials: F
authors.lastname: Yin
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
authors.forename: Junyi
authors.initials: J
authors.lastname: Zhang
authors.forename: Lan
authors.initials: L
authors.lastname: Yu
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Li
authors.forename: Kun
authors.initials: K
authors.lastname: Xu