An internal eight-band LTE/WWAN handset antenna integrated with a USB connector is presented. The proposed antenna comprises an antenna ground which faces a protruded ground extended from the main ground of the handset to accommodate a USB connector. The antenna ground is used as a shorting portion to short-circuit the antenna to ground such that the coupling between the antenna ground and the protruded ground is effectively suppressed. In this case, the proposed antenna can be integrated with a USB connector mounted on the protruded ground, leading to compact integration of the antenna inside the handset. Good radiation characteristics of the antenna are also obtained, and the proposed antenna occupies 60 ¡Ñ 12 ¡Ñ 4.8 mm3 (about 3.4 cm3) only. Effects of the user¡¦s head and hand on the proposed antenna are studied, and the simulated SAR and HAC results are also analyzed in this thesis.

In this thesis, two types of handset antenna design respectively for dual-band GSM850/1900 operation and seven¡Vband LTE/WWAN operation are presented. The proposed antennas can achieve decreased antenna size and enhanced operating bandwidth by shaping the system ground plane of the handset. The seven-band LTE/WWAN antenna is printed on the system circuit board with good radiation characteristics and occupies a small size of 24.5 x 10 mm2. At first, we propose a half-loop antenna structure which integrates its facing edge of the system ground plane as the resonant path of the antenna. In this case, the required length of the half-loop antenna structure is only about a half compared with the traditional loop antenna. Next, to enhance the operating bandwidth of the antenna, a parasitic shorted monopole strip is added and a shaped system circuit board is used. The shaped system circuit board can integrate the battery with the circuit board to help reduce the thickness of handset. Also, much enhanced operating bandwidth for the lower band can be obtained, owing to the enhanced surface current excitation in the system ground plane resulting from properly shaping the system circuit board. Effects of the user¡¦s head and hand on the proposed antenna are studied, and the simulated SAR and HAC results are also analyzed for bio-compatibility issue.

In this dissertation, novel printed multiband antennas for slim mobile communication devices are presented. The design techniques on achieving decreased antenna size and enhanced operating bandwidth in different shaped system ground planes with the antennas printed thereon are proposed. At first, a WWAN antenna integrated with a U-shaped ground plane is presented. Two techniques are applied to achieve WWAN operation with a small antenna size. The first technique is to embed load a proper chip inductor at a proper position in the shorted strip monopole of the antenna. The second one is to use a band-stop matching circuit disposed on the main circuit board of the handset. For the second and third antenna designs, owing to the C-shaped ground plane, much enhanced operating bandwidth for their lower band can be obtained. The second antenna design can cover the LTE/WWAN eight-band operation without increasing the size of the antenna by using a reconfigurable circuit element. The third antenna design integrated with a battery element and a metal midplate for practical application to help reduce the thickness and enhance the robustness of handset. The antenna can cover seven-band LTE/WWAN operation with good radiation characteristics and occupy a small size of 35 x 8 mm2. Finally, the simulated SAR and HAC results are analyzed for bio-compatibility consideration.

In this thesis, an internal mobile phone antenna with a distributed matching circuit for eight-band LTE/WWAN operation is presented. By selecting proper dimensions of the distributed matching circuit, the bandwidth of the proposed antenna can be greatly enhanced. Good radiation characteristics are also obtained, and the proposed antenna occupies only 60 ¡Ñ 10 ¡Ñ 3 mm^3 and is very suitable for slim mobile phone applications. Effects of the human body including user¡¦s head and hand are also studied, and the SAR and HAC issues are simulated and analyzed in this thesis.

Bandwidth enhancement of the LTE/WWAN handset antenna achieved by improving the excited surface current distribution in the system ground plane is presented. To achieve this goal, the system ground plane is shaped to be of a C-shape in this thesis. In this case, the longitudinal excited surface current in the system ground plane can have a smooth distribution. The proposed antenna is disposed at one edge of the C-shaped system ground plane, and the antenna comprises a driven monopole strip, a shorted monopole strip and a distributed parallel resonance (PR) circuit. By controlling the resonant frequency of the distributed PR circuit, it can result in dual-resonance excitation of the lowest resonant mode contributed by the shorted monopole strip to cover the LTE700/GSM850/900 operation. The antenna also occupies a small volume of 44 ¡Ñ 10 ¡Ñ 5 mm3 (about 2.2 cm3). Good radiation characteristics of the antenna are also obtained. For practical applications, effects of the electrical connection between the system ground plane and the surrounding metal elements such as the battery¡¦s metal casing and the handset metal midplate are studied. The simulated SAR (Specific Absorption Rate) and HAC (Hearing Aid Compatibility) results are also analyzed.