Development of active integrated antennas and optimization for harmonic suppression antennas. Simulation and measurement of active antennas for amplifiers and oscillators and numerical solution on design and optimization of active patch antennas for harmonic suppression with adaptive meshing using genetic algorithms.
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Publication date
2007-07-10Supervisor
Abd-Alhameed, Raed A.Keyword
Active integrated antennaClass F
Active oscillator antenna
AM Modulation
ASK Modulation
Sensor patch
Harmonic suppression
Genetic algorithms
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The University of Bradford theses are licenced under a Creative Commons Licence.
Institution
University of BradfordDepartment
School of Engineering Design and TechnologyAwarded
2007Metadata
Show full item recordAbstract
The objectives of this research work are to investigate, design and implement active integrated antennas comprising active devices connected directly to the patch radiators, for various applications in high efficiency RF front-ends, integrated oscillator antennas, design and optimization of harmonic suppression antennas using a genetic algorithm (GA). A computer-aided design approach to obtain a class F operation to optimizing the optimal fundamental load impedance and designing the input matching circuits for an active integrated antenna of the transmitting type is proposed and a case study of a design for 1.6 GHz is used to confirm the design principle. A study of active integrated oscillator antennas with a series feed back using a pseudomorphic high electronmobility transistor (PHEMT) confirms the design procedure in simulation and measurement for the oscillator circuit connected directly to the active antenna. Subsequently, another design of active oscillator antenna using bipolar junction transistor (BJT) improves the phase noise of the oscillation and in addition to achieve amplitude shift keying (ASK) and amplitude modulation (AM) modulation using the proposed design circuit. Moreover, the possibility of using a sensor patch technique to find the power accepted by the antenna at harmonic frequencies is studied. A novel numerical solution, for designing and optimizing active patch antennas for harmonic suppression using GA in collaboration with numerical electromagnetic computation (NEC), is presented. A new FORTRAN program is developed and used for adaptively meshing any planar antenna structure in terms of wire grid surface structures. The program is subsequently implemented in harmonic suppression antenna design and optimization using GA. The simulation and measurement results for several surface structures show a good agreement.Type
ThesisQualification name
PhDCollections
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