2022-06-03
New doctoral dissertation
VILNIUS TECH Library invites you to follow the published new dissertations. The dissertation „Design of transimpedance amplifiers for broadband time-domain optical reflectometer systems“ prepared by VILNIUS TECH, Agata Romanova, is presented in English. The dissertation was prepared in 2017–2022, supervisors – Assoc. Prof. Dr Vaidotas Barzdėnas.
The dissertation was defended at the public meeting of the Dissertation Defense Council of Electrical and Electronic Engineering in the Senate Hall of Vilnius Gediminas Technical University at 10 a. m. on 3 June 2022.
„The tremendous growth of Internet traffic in recent years had led to the rapid development of broadband optical communication systems. This rapid growth also increases a demand for the equipment for network deployment, monitoring and repair. One of the typically used instruments is based on a technique known as Optical Time-Domain Reflectometry - OTDR. These instruments are used for characterization and fault detection in optical fibers is based on the analysis of the reflections in time domain. The research object of the doctoral dissertation is the design and analysis of an programmable-gain CMOS TIA suitable for modern OTDR applications. In order to compare quantitatively different TIA architectures as well as designs produced using different technologies, the work suggests a quantitative measure - Figure-ofMerit (FOM). After evaluating advantages of different TIA types, the dissertation suggests a novel programmable-gain capacitive feedback TIA architecture with PMOS transistor-based biasing circuit for source follower which allows to implement a low-noise broadband TIA. Based on the suggested architecture and using 0.18 µm CMOS and 0.25 µm BiCMOS technologies, TIAs were designed with 1.0 GHz and 0.9 GHz bandwidths accordingly, 10 kΩ, 25 kΩ, 100 kΩ, 200 kΩ and 500 kΩ discretely adjustable gains, 1.8 and 1.6 pA/√ Hz noise current spectral densities, 21 mW and 29 mW power consumption at correspondingly 1.8 V and 2.5 V supply voltages and their major characteristics were investigated.“
Doctoral dissertation readers can search via VILNIUS TECH Virtual Library
The dissertation was defended at the public meeting of the Dissertation Defense Council of Electrical and Electronic Engineering in the Senate Hall of Vilnius Gediminas Technical University at 10 a. m. on 3 June 2022.
„The tremendous growth of Internet traffic in recent years had led to the rapid development of broadband optical communication systems. This rapid growth also increases a demand for the equipment for network deployment, monitoring and repair. One of the typically used instruments is based on a technique known as Optical Time-Domain Reflectometry - OTDR. These instruments are used for characterization and fault detection in optical fibers is based on the analysis of the reflections in time domain. The research object of the doctoral dissertation is the design and analysis of an programmable-gain CMOS TIA suitable for modern OTDR applications. In order to compare quantitatively different TIA architectures as well as designs produced using different technologies, the work suggests a quantitative measure - Figure-ofMerit (FOM). After evaluating advantages of different TIA types, the dissertation suggests a novel programmable-gain capacitive feedback TIA architecture with PMOS transistor-based biasing circuit for source follower which allows to implement a low-noise broadband TIA. Based on the suggested architecture and using 0.18 µm CMOS and 0.25 µm BiCMOS technologies, TIAs were designed with 1.0 GHz and 0.9 GHz bandwidths accordingly, 10 kΩ, 25 kΩ, 100 kΩ, 200 kΩ and 500 kΩ discretely adjustable gains, 1.8 and 1.6 pA/√ Hz noise current spectral densities, 21 mW and 29 mW power consumption at correspondingly 1.8 V and 2.5 V supply voltages and their major characteristics were investigated.“
Doctoral dissertation readers can search via VILNIUS TECH Virtual Library