RT Dissertation/Thesis
T1 Advancing the extraction and robustness of admittance behavioural models for use in CAD design of nonlinear microwave circuits
T2 Melloras na extracción e robustez de modelos comportamentais de admitancias para o seu uso no deseño CAD de circuitos non lineais de microondas
A1 Moure Fernández, María del Rocío
K1 3307.08 Dispositivos de Microondas
K1 3307.19 Transistores
K1 3307.14 Dispositivos Semiconductores
AB The design of nonlinear active analogue circuits for present and future wireless communications systems (WiFi, WiMAX, 5G mobile networks…), is a complex process, since transceiver modules are required to meet strict specs in terms of power, noise, bandwidth, linearity, efficiency and energy consumption, along with reduced weight and size, and the ability to operate with complex signals or multi-band/mode environments.As an example, power amplifier (PA) design using complex configurations, like continuous mode class B/J or Doherty, is nowadays providing very good performance in terms of energy efficiency.  But bandwidth improvements in these circuit architectures is not a trivial task.  In fact, achieving adequate PA behaviour in wideband usually degrades its performance in comparison with narrowband PAs.  Still, continuous class J and wideband Doherty configurations are providing good results.  Nevertheless, the design of this type of amplifiers for C- and higher bands is still a challenge.The present nonlinear circuits improved performance is not only the consequence of improvements in the transistor technology and circuit architectures, but also due to new nonlinear vector characterization techniques for active devices.  The recent development of nonlinear device behavioural models, which show high accuracy in large signal and excellent computational efficiency in complex circuits, is another important contribution.  Among these behavioural models, the X-parameters and the Cardiff model have been successfully used in the design of nonlinear circuits, like PAs, oscillators or mixers.  These travelling wave (A-B) formulated behavioural models will be the starting point of this work.This thesis work will focus on the emerging admittance-based (V-I) behavioural formulation.  It has been proposed that this modified frequency domain formulation is more appropriate for use in designing state-of-the-art nonlinear circuits where large bandwidth or dual-band requirements are the key drivers.  This work will be performed at the University of Vigo (UVigo), initially in the framework of the project titled: “New nonlinear transistor behavioural models and design technologies for dual-band PAs for light weight multicopter drones” (cod. TEC2014-60283C3-3-R), a project in which are involved UVigo, UC y UPGC.The main objective of this thesis work is to advance the understanding of nonlinear behavioural admittance models (defined in the frequency domain) from the perspective of providing an accurate and robust tools for CAD-based design of nonlinear circuits in the microwave band.  Aspects, such as, model optimum complexity and fundamental frequency scaling potential will be investigated.  Approaches to improve the extraction of these models from load-pull data, and the development of the corresponding nonlinear characterization tools are also undertaken.As part of this work, a large-signal measurement system will be set-up, based on the NVNA PNA-X analyser from Keysight Technologies (available at the AtlantTIC research Center), to perform microwave high power vector calibrated measurements with variable load termination (passive load-pull), up to 25W peak RF power and up to 18GHz.Finally, the transistor characterization methodology and required control of the measurement system software for models extraction and validation will be developed, as well as the routines for model extraction.
YR 2019
FD 2019-12-17
LK http://hdl.handle.net/11093/1394
UL http://hdl.handle.net/11093/1394
LA eng
NO Ministerio de Ciencia e Innovación | Ref. TEC2014-60283-C3-3-R
DS Investigo
RD 04-dic-2024