Mobile telephone antennas that can be integrated into the handset offer several advantages compared to conventional external antennas such as monopoles or helix. They are less easily broken off, reduce power absorption by the head and are less sensitive to the geometry of the handset. A potential candidate for an integrated antenna is the Dielectric Resonator Antenna (DRA) but it is still considered too large for applications at 900MHz. Additionally in many parts of the world mobile telephone systems have been allocated spectrum centered around both 900MHz (cellular systems) and 1800MHz (Personal Communication Systems) with the corresponding demand that mobile telephones operate in both bands. Together with the need to provide multiple antennas at the handset for diversity, there is con...[ Read more ]

Mobile telephone antennas that can be integrated into the handset offer several advantages compared to conventional external antennas such as monopoles or helix. They are less easily broken off, reduce power absorption by the head and are less sensitive to the geometry of the handset. A potential candidate for an integrated antenna is the Dielectric Resonator Antenna (DRA) but it is still considered too large for applications at 900MHz. Additionally in many parts of the world mobile telephone systems have been allocated spectrum centered around both 900MHz (cellular systems) and 1800MHz (Personal Communication Systems) with the corresponding demand that mobile telephones operate in both bands. Together with the need to provide multiple antennas at the handset for diversity, there is considerable interest in designing antennas that are compact.

This thesis is concerned with the design of DRAs that are sufficiently compact for use in handsets. Significant volume reductions of the DRA are demonstrated by utilising circular sector DRAs. A compact DRA design is proposed, simulated with the Finite Difference Time Domain (FDTD) method and tested for the PCS system. In addition a novel circular sector DRA approach used to produce circular polarisation for satellite communication systems such as global positioning systems (GPS) and satellite-mobile communications is also discussed and prototypes are used to verify the findings.