Chia-Lun Tang

Internal shorted patch antenna for a UMTS folder-type mobile phone

A novel design of feeding and short-circuiting an internal patch antenna for mobile phones is presented. The patch antenna comprises a simple rectangular patch that is fed through and short-circuited to a small ground plane (denoted as antenna ground here) which protrudes from the main or bottom ground of a folder-type mobile phone. With the presence of the small antenna ground, which can function as a shielding wall, the proposed antenna can be placed in close proximity to the RF shielding metal box in the mobile phone, with very small effects on the antenna performances. A design example of the proposed antenna for Universal Mobile Telecommunication System (UMTS) (1920/spl sim/2170MHz) operation is demonstrated. Experimental and simulated results are presented.

Broadband omnidirectional metal-plate monopole antenna

A novel broad-band omnidirectional metal-plate monopole antenna is presented. The proposed antenna is a step-shaped metal-plate monopole, which is easily fabricated from bending a metal plate (a 0.2 mm thick brass sheet used in this study). The proposed antenna shows improved omnidirectional radiation for frequencies across a very wide operating bandwidth (frequency ratio about 1:3), compared to a corresponding planar monopole antenna. Details of the proposed antenna design are described, and the experimental performance of some prototypes is studied.

EMC internal patch antenna for UMTS operation in a mobile device

A novel patch antenna suitable to be applied in a mobile device as an internal antenna having an electromagnetic compatibility (EMC) property with nearby conducting elements is presented. The antenna is easily fabricated from a single metal plate and mainly comprises a top patch and an inverted-L vertical ground wall. Due to the presence of the inverted-L ground wall, which is perpendicular to the system ground plane of the mobile device, the possible fringing EM fields in the surrounding region of the antenna are suppressed. In this case possible coupling between the antenna and the nearby conducting elements is expected to be small, and thus degrading effects on the performance of the antenna are eliminated. A design example of the proposed antenna for Universal Mobile Telecommunication System (UMTS) 1920-2170 MHz operation in a mobile device is demonstrated and discussed.

Wideband monopole antenna integrated within the front-end module package

A novel wideband monopole antenna integrated within the front-end module package for WLAN and/or WiMAX operation in the 5 GHz band for a mobile device is presented. The front-end module package mainly comprises a bent /spl pi/-shaped wideband monopole antenna for 5 GHz band operation and a shielding metal case for accommodating the associated module and circuitry. The antenna is integrated to the shielding metal case through short-circuiting. For practical applications, the proposed front-end module package is to be mounted at one of the corners of the system circuit board of the mobile device. In this case, the shielding metal case not only performs as part of the ground plane of the antenna, but also functions as a shielding metal block to shield the antenna from the undesired coupling with nearby electronic or conducting elements in the mobile device. The proposed design of the front-end module package with an embedded antenna is studied, and obtained results of the constructed prototypes are presented.

User's hand effects on EMC internal GSM/DCS mobile phone antenna

The users hand effects on the EMC GSM/DCS antenna embedded in the mobile phone have been presented. Although the EMC antenna is easy to be integrated into a mobile phone with nearby electronic components or conducting elements, the performance of the antenna is still greatly affected when a users hand holds the mobile phone. Even when the phone was hand-held at the bottom, large efficiency drops have been observed, especially for the GSM operation

A low-profile omnidirectional circularly polarized antenna for WLAN access point

Omnidirectional CP antennas have the advantage that no strict orientations between the access point, and the mobile unit are required for WLAN operation. For this reason, it can be expected that the omnidirectional CP antenna should find great application in WLAN operation. For such promising applications, we propose a novel omnidirectional CP antenna with a low profile of less than 10 % of the wavelength of the center operating frequency. The proposed antenna consists of a top-loaded cylindrical monopole for generating omnidirectional vertical linear polarization (LP) radiation and four printed arc-shaped dipoles for generating omnidirectional horizontal LP radiation. The vertical and horizontal LP radiation can further be adjusted to be of equal amplitude and a 90/spl deg/ phase difference, thereby resulting in omnidirectional CP radiation. A prototype of the proposed antenna suitable for applications in a 2.4 GHz (2400-2484 MHz) WLAN access point is constructed and studied.

Simplified hand model for the study of hand-held device antenna

This paper proposes a one-layer simplified hand model incorporating the use of 3D FDTD simulation software, SPEAG SEMCAD-X (simulation platform for EMC, antenna design, and dosimetry) for achieving efficient simulation for hand-held device antennas. The case of the GSM/DCS internal mobile phone antenna with the proposed hand model is first presented. Effects of the proposed hand model including the users forearm on the impedance and radiation characteristics of the internal antenna are analyzed. A second case of the DTV antenna in the PMP device with proposed hand model is also studied

Internal shorted patch antenna for UMTS mobile phone

In this paper we present a new internal mobile telephone antenna design to eliminate the required isolation distance between the antenna and the RF shielding metal box to provide a promising alternative for integrating various elements inside a mobile telephone. A design example of the proposed shorted patch antenna applied to a UMTS (Universal Mobile Telecommunication System, 1920/spl sim/2170 MHz) folder-type mobile telephone is demonstrated. Results of a constructed prototype are presented and discussed.