10 Gb/s Switchable Binary/PAM-4 Receiver and Ring Modulator Driver for 3-D Optoelectronic Integration

Abstract

This paper presents ring modulator driver and receiver circuits designed for 3D photonic-electronic integration using inter-wafer connections (IWC), whose parasitic capacitance is expected to be in the order of 15 fF. Both transmitter and receiver can operate with binary and PAM-4 modulation at 10 Gb/s. To the authors knowledge it is the first PAM-4 ring modulator driver being presented. The circuits are designed in AMS 0.35 µm SiGe BiCMOS technology with total power consumptions of 160 mW and 180 mW for transmitter and receiver, respectively. The receiver's sensitivity is -27 dBm for binary and -22 dBm for 4-PAM signals both at a photodiode responsivity of R = 0.9 A/W. A monitor TIA with sensitivity -32 dBm was also designed in order to control the operating point of the ring modulator.

Highly sensitive 10 Gb/s PAM‐4 optical receiver circuit for three‐dimensional optoelectronic integration

“…The area of the circuit presented in this paper equals 0.574 mm 2 , whereas the RX from [14] occupies 0.632 mm 2 , which is a considerable difference of nearly 10%. The RX from [14] has the largest power consumption of all circuits in Table 1.…”

“…References [10–14] report on PAM‐4 optical RXs. Circuits [10, 11] are designed for wire‐bonded PDs and their post‐layout simulation results are presented.…”

“…The PAM‐4 optical RX from [13] had a measured –16 dBm sensitivity, which is a good value considering that responsivity of its photodetector was only 0.51 A/W. The circuit from [14] is an optical RX for 3D‐integrated OEICs designed in the same technology as the RX presented in this paper. These two circuits show nearly the same sensitivity.…”

A Bi-CMOS electronic photonic integrated circuit quantum light detector

“…A monolithic design reduces C in by minimizing the stray capacitance between the photodiodes and amplifier due to bondpads or other wiring related sources. This comes in addition to the already low capacitance associated with integrated photodiodes and high-performance HBTs—integrated photodiodes with capacitances as low as 9 fF and amplifier input capacitance of order of 100 fF have been reported ( 30 , 51 ). This is in stark contrast to the packaging and layout-associated parasitic capacitance on a PCB of up to tens of picofarads ( 23 , 52 ).…”