User requirements for access to a diversified range of wireless telecommunication services have resulted in a rapid technological push to unify these several different systems on a common platform. The objective of this work is to develop novel antenna design solutions not only for existing systems but also any future generation wireless communication systems. This thesis titled "Novel Antenna Design for Future Mobile Systems" describes the work done for the period from 15th January 1998 to 14th January 2001, under the studentship agreement between British Telecommunications and the University of Birmingham. Three topics are investigated in this thesis. They are: firstly, the family of multiband planar inverted F antenna (PIFA); secondly, the gain enhancement and packaging concepts of electrically small antennas and finally, the family of multiband fractal antennas. In the first topic, two novel PIFA antennas were designed. The first is a triple band antenna where a dual band single feed element using a reactive L shape spur line load is housed within a lower frequency antenna element. The frequency ratio for the reactively loaded dual band single feed antenna is tuneable between 1.28 to over 3.5. The second antenna is designed with two PBFA housed within a quarter wave patch antenna. The antenna is tuned for operation in the GSM, DECT and WLAN bands. The second includes a discussion of a method of integrating electrically small antenna with the transceiver chip on a single package, where the poor efficiency of small integrated antenna can be overcome by the use of a parasitic radiator. Experimental investigation of the characteristics of this parasite, including circular polarisation techniques, are addressed. The final topic is the family of multiband fractal antennas where five novel designs are proposed. The first two designs address feeding solutions for a perturbed Sierpinski gasket monopole antenna, using a microstrip and an angular feed. These techniques enable the closely spaced, tuned bands of the perturbed Sierpinski gasket to be matched without additional matching circuits. The third design is a shorted half sized Sierpinski gasket monopole antenna, similar to the design of the inverted L antenna development. Tuning of bands are also demonstrated by structural perturbation. The fourth design is a set of multiple rings, similar to the multi-level design of the Sierpinski gasket monopole antenna. The bandwidth of each band is well over 40%, which is much larger than the Sierpinski gasket monopole. Finally, a pair of Sierpinski carpet monopoles are fed in parallel and demonstrate a very large impedance bandwidth.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:633236 |
| Date | January 2001 |
| Creators | Song, Peter C. T. |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0021 seconds