Characterization of a high-speed radio-frequency sampling and demultiplexing circuit based on the cascade connection of pin photodiodes

Abstract

Herein, we apply theoretical models to characterize the transfer function and frequency response of acomplex optoelectronic circuit that comprises a primary ultrafast sampling circuit followed by a cascade connection of Ndemultiplexing stages. The successive radio-frequency optoelectronic samplers were based on the cascade connectionof positive-intrinsic-negative-photodiodes (PIN-PDs). We developed a procedure to calculate the principal designparameters that allows us to use optical power for each sampling and demultiplexing stage, such that the circuit can bedesigned based on the application requirements. The results obtained from the theoretical models were compared withthe measurements obtained from the 2.5 GS/s sampling circuit connected in cascade with a 1.25 GS/s and a 625 MS/sdemultiplexing circuit implemented using commercial PIN-PDs.