Abstract
With the rapid growth of computing and data storage, optical communication has become a popular research topic recently. In this thesis, we focus on designing high speed transmitters of optical communications. The first four chapters show the design and implementation of modulator drivers in different topologies and technologies. In chapter five, the 90nm CMOS technology is used to design a laser diode driver. Finally, a conclusion is given in chapter six. In chapter 2, a 40 Gb/s distributed amplifier (DA) with an inductor peaking technique in 90 nm CMOS has been implemented. The power consumption of the DA was about 408 mW under a supply voltage of 6 V. The DA reaches a voltage swing over 2.5 V with an operation speed of 25 Gb/s and 1.5 V swing at 40 Gb/s. The chip area is 10.5 mm2. The measurement results show this design is capable of 25 Gb/s operation. In chapter 3, a compact 40 Gb/s modulator driver is proposed and implemented in 40 nm CMOS for the purpose of integration with the silicon-based high speed modulator, provided by University of Southampton Optoelectronics Research Center. Under the termination of 50 , the modulator driver can reach a 1.76 V peak-to-peak voltage swing (Vpp) and 1.41 V_PP at the speed of 12.5 Gb/s and 22 Gb/s respectively under electrical measurements. Also, the extinction radios are 4.9 dB and 3.27 dB at 10 Gb/s and 20 Gb/s for optical measurements. The power consumption is 308 mW and the area is 0.62 0.53 mm2. In chapter 4, a 40 Gb/s inductorless modulator driver is proposed and implemented in 0.13-μm SiGe BiCMOS technology, provided by the Innovations for High Performance Microelectronics (IHP). The simulated results show a 3-dB bandwidth up to 51.8 GHz while consuming 389 mW under a supply voltage of 5 V. The voltage swing is 2.35 V and the chip area is 650 450 mm2. The simulated eye diagram is well opened at the speed of 40 Gb/s. In chapter 5, a laser diode driver incorporating the proposed totem pole output stage and asymmetric inductors can achieve a voltage gain of 2.5 dB and a bandwidth of 16.5 GHz with a power consumption of 125.4 mW. A driver using the totem pole configuration can easily transfer the differential signal to single ended. With the proposed asymmetric inductors, both signal paths will have a similar gain leading to a good characteristic of eye diagram. This driver can operate at 25 Gb/s while delivering 70 mA to the load of a 10-Ω laser diode. The circuit is fabricated in 90 nm CMOS technology, operating with a 2-V supply. Keywords: Distributed amplifier, Modulator driver, Laser diode driver, Optical interconnect system, and 3D inductor.