Design of a Transimpedance Amplifier for an Optical Receiver

• Autor(a) principal: Carvalho, João Pedro Leal Abalada De Matos
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/34375
• topic: Fiber optics; Transimpedance amplifiers; Amplifier gain; Bandwidth; Input reffered noise; Complementary metal-oxide-semiconductor (CMOS); Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática

In today’s world, technology is so developed that it is possible to transmit huge amounts of data in a short time. In the experiments with high energy levels in laboratories carried out in CERN, it is essential to have a method capable of carrying all this information and at the same time of being tolerant to the radiation from these same experiments. Optical fibres are currently the best method transmitting the data created by these experiments. In order to receive the information from the optical fibre a Photodiode (PD) is used to produce current from the light of the optical fibre. This current is however small. It is necessary to use an amplifier which, in addition to amplifying the current coming from the photodiode, also converts it into a voltage for the next phases of the optical receiver. These amplifiers are known as transimpedance amplifiers and are the critical part of optical receivers since an high gain is required to amplify the current from the photodiode and at the same time a high bandwidth to receive the hight data rate signals. This thesis presents a complete analysis of these amplifiers, showing various types of topologies and their pros and cons. In order to arrive at the amplifier with the desired characteristics, this thesis uses mathematical equations that allow us to describe the operation of the Transimpedance Amplifier (TIA) and to determine the optimal range between the gain, the bandwidth and the noise of the amplifier (input referred noise). All the theoretical expressions as well as the behaviour of the whole system was verified using electrical simulations.