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

This paper presents ring modulator driver and receiver circuits designed for three-dimensional photonic–electronic integration using interwafer connections, 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 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 transimpedance amplifier with sensitivity –32 dBm was also designed in order to control the operating point of the ring modulator.