15-40Gb/s High Speed Parallel Front-End Amplifiers For Optical Receiver Design

With the rapid development of Internet, broad bandwidth is on demand greatly. More and more Internet equipments such as Router, ATM, OXC and DWDM are placed together. Because of ultra high-speed transmission data, very short reach (VSR) optical transmission system is the best choice here both for performance and price considerations.As the critical role of the optical receiver, the preamplifier's performance has great effect on the performance of the whole optical receiver. Transimpedance amplifiers (TIA) are widely used in the high speed optical transmission systems. An auto Gain Control (AGC) amplifier or a limiting amplifier is generally used to realize the main amplifier. The latter one was chosen to realize the main amplifier in our design since it has the feature such as simple topology, few external components and fast responsibility. In this paper, TSMC 0.25μm CMOS technology is used to realize the design of parallel front-end amplifiers for VSR4-1. An improved common source TIA is used in the design of pre-amplifiers, which can meet the request of bandwidth and noise performance simultaneously. Active loads amplifiers cell are used to construct the limiting amplifier. On the basis of theory analysis and design optimization, the circuit achieves high performance of gain, bandwidth, noises and power dissipation.In this paper, TSMC 0.18μm CMOS technology is used to realize the design of parallel front-end amplifiers for both VSR4-1 and VSR5. The RGC structure is used in the design of pre-amplifiers, which overcomes the inadequate bandwidth problem caused by the large parasitical capacitor of CMOS photodiode. Modified Cherry-Hooper amplifiers are used to construct the limiting amplifier. On the basis of theory analysis and design optimization, the circuit achieves high performance of gain, bandwidth, noises and power dissipation.In this paper, firstly the knowledge about VSR transmission system is introduced; subsequently the design procedure and test results are presented. According to the measurement results, the pre-amplifier, limiting amplifier and circuit are suitable for VSR application.Creative point on isolation is validated by both the theory and the measurement, so one national technology patent was applied in May, 2005, and the applied number is 200510040731.x Consigned by Jiangsu Science and Technology department, Jiangsu Education Department held the achievement appraisal meeting of 15-30Gb/s High Speed Parallel Front-end Amplifiers for Optical Receiver on August 20, 2005. The performance of chip is authenticated as the international advanced level.