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Title: Non-linear analysis of optical and microwave sources
Author: Afroozi Milani, Mohammad
ISNI:       0000 0004 5914 8974
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2016
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Due to the ever increasing need for better and more capable communication systems, a large quantity of research is focused on the design and simulation of different sections of communication systems including the communication sources. Due to the massive cost of the fabrication involved in designing new communication sources, the accurate modelling and design of these sources using Computer Aided Design is of great interest. In this thesis fundamentals of laser modelling and nonlinear microwave antenna design; followed by reviewing the most important works carried out by other researchers in these fields. The thesis continues by introducing a proposed, accurate model of the Vertical Cavity Surface Emitting Laser (VCSEL). The proposed model integrates the effects of the matching network as well as the parasitics, due to the VCSEL chip and the packaging mounting and the intrinsic VCSEL noise sources. Further in this thesis, a nonlinear Composite Right/Left Handed frequency doubler Leaky Wave Antenna is designed which is capable of transmitting a signal in a direction that can be varied continuously from backfire to endfire, by varying the input frequency to the structure. The novelty of the proposed design is in the inclusion of nonlinear elements in the CRLH structure and also in the use of a quasi-lumped approach when designing the distributed structure. Finally, in this thesis a novel method of combining harmonic balance and EM analysis for the design and optimisation of nonlinear active antennas is developed. This method responds to the restriction of the CAD software in conveniently combining the analysis of nonlinear active antennas with advanced EM simulations such as radiation patterns. The proposed method enables the advanced EM analysis at the harmonic frequencies, generated within the nonlinear microwave structures when the structure is exited at the fundamental frequency, to be combined with full electromagnetic simulators.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QC Physics ; TK Electrical engineering. Electronics Nuclear engineering