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Title: Electromagnetic bandgap (EBG) structure based patch antennas
Author: Gnanagurunathan, Gnanam
ISNI:       0000 0004 2716 5155
Awarding Body: University of Nottingham
Current Institution: University of Nottingham
Date of Award: 2012
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Microstrip patch antenna is used extensively in wireless and mobile applications due to its low-profile and lightweight. However, this antenna is prone to low gain, limited bandwidth and increased cross polarization levels. Electromagnetic Bandgap (EBG) structures are able to enhance the performance of this type of antenna. In this work, the performance of the patch antenna when integrated with EBG structure is investigated. A preliminary simulation study on the performance of a microstrip patch antenna integrated with Electromagnetic Bandgap (EBG) structures, indicated improvement in the radiation characteristics. First, the EBG characterization effort is undertaken. The bandgap of complementary and non-complementary form of five geometries are analyzed using the transmission line method. The analysis through simulation and measurement, show that complementary form sees a significant shift in the bandgap to lower frequencies and offer wider bandgap when compared to non-complementary form. Subsequently, gain performance of a square patch antenna when it is enclosed by complementary forms of either circular or square EBG cells are investigated. It emerges that the use of complementary EBG cells results in a comparatively better gain performance. The study includes a consideration of the groundplane size and the number of rows surrounding the patch, as these could affect the gain performance. This is followed by experimental measurements to substantiate the simulation outcome. Finally, the gain performance of a wideband antenna when it is configured with an EBG structure which functions as a reflector, also known as Artificial Magnetic Conductor (AMC) is investigated and reported. Four variations of the AMC structure are investigated i.e. a square cell backed by square cells (with and without vias) and square cells backed by a PEC (with and without vias). The properties of gain, impedance bandwidth and power patterns are measured and reported over the wideband frequencies of 3-10GHz.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: TK7800 Electronics