Transversal Filter MMIC design for Multi–Gbit/s Optical CDMA Systems
Diseño de Filtro Transversal Monolítico Integrado de Microondas ( MMIC) para los Sistemas Ópticos CDMA en el Régimen de Multi–Gbits/s
Graduated: Jorge Aguilar Torrentera
Sección de Comunicaciones
ClNVESTAV – I.P.N.
Av. Instituto Politécnico Nacional # 2508, ]]>
Col. San Pedro Zacatenco, 07360, México, D.F.
jaguilarumist@yahoo.com
Graduated on: November 27,2004
Supervisor: Izzat Darwazeh
Department of Electronic and Electrical Engineering
University College of London
Torrington Place, London WC1E 7JE
i.darwazeh@ee.ucl.uk
Abstract
]]> In this work, the approach of the distributed transversal filter for Optical COMA systems is addressed. It demonstrates that pulse generation and correlation functions can be accomplished in the electrical domain for multi–Gbit/s systems. The practicalities of the approach were assessed using a state of the art GaAs MMIC process. A innovate transversal filter, which is termed the dual drain–line transversal filter, was proposed and designed for speed operations exceeding 40 Gbit/s. A new tap gain weight control technique was designed for the proposed topology so that the filler can be modelled with constant distributed characteristics. A framework based on mixed–mode scattering parameters was derived to investigate the various frequency responses of the filter. Similarly, time domain results based on the full parameters of the MMIC design proves the efficacy of the approach. The filter satisfies the first Nyquist criterion and is suitable for multi–Gbit/s CDMA systems.Keywords: Fibre Networks, Optical–CDMA Systems, Distributed Amplifiers, HEMTs, Transversal Filter, GaAs MMICs
Resumen
Este trabajo de tesis estudia la aplicación de filtros transversales utilizando la técnica de CDMA para los sistemas ópticos de alta velocidad. Se demuestra prácticamente que funciones tales como generación de pulsos y correlación se pueden llevar a cabo utilizando circuitos electrónicos. La viabilidad de estos desarrollos se comprobó mediante el diseño de un circuito monolítico integrado de microondas (MMIC) basado en un proceso comercial de arseniuro de galio (GaAs). Un filtro transversal no reportado con anterioridad, el cual se le denomina filtro transversal con líneas de drenaje dual, fue propuesto y diseñando para velocidades de operación mayores a 40 Gbit/s. Una nueva técnica de control de coeficientes del filtro se diseñó para la topología propuesta de tal forma que el filtro puede ser modelado con características de circuito distribuido constantes. Una estructura de análisis, el cual se basa en parámetros de dispersión de modos mezclados, fue derivada para investigar las diferentes respuestas en frecuencia de la estructura. Similarmente, resultados en el dominio del tiempo que utilizan los parámetros del diseño del circuito integrado muestra la eficiencia de la propuesta. El filtro satisface el primer criterio de Nyquist y es adecuado para sistemas CDMA que trabajan a velocidades de gigabit por segundo.
Palabras Clave: Redes de fibra óptica, Sistemas Ópticos CDMA, Amplificadores Distribuídos, HEMTs (transistores de Alta Movilidad Electrónica), Filtro Transversal, GaAs MMICs (Circuitos de Microondas Monolíticos Integrados de Arseniuro de Galio).
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