Summary
International Symposium on Antennas and Propagation
2010
Session Number:2WC1
Session:
Number:2WC1-1
Printed WWAN Coupled-Fed Loop Antenna Closely Integrated with Nearby System Ground Plane for Mobile Phone Application
Ting-Wei Kang, Wei-Yu Chen, Kin-Lu Wong,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
On-board internal printed antennas for penta-band WWAN operation are attractive for slim mobile phone applications. In order to achieve wideband operation, these reported internal printed WWAN antennas in the mobile phone are usually required to occupy the entire top edge or bottom edge of the system circuit board, and generally require an additional isolation board space to obtain negligible coupling effects between the antenna’s radiating portion and the nearby ground plane [1]- [3]. This limits the compact integration of the internal printed WWAN antenna with the associated electronic components inside the mobile phone. For example, in order to achieve decreased SAR [4], it is preferred that these printed WWAN antennas be positioned at the bottom edge of the mobile phone. In this case, the integration of the antenna with the associated electronic components such as a USB connector that is usually mounted at the bottom edge of the system circuit board as a data port for the mobile phone becomes a challenging design issue. To solve the problem, the on-board printed antenna should not occupy the entire bottom edge of the circuit board and can also be in close proximity to a protruded ground which is connected with the main ground and has a size large enough to accommodate the USB connector (typical size 9 × 7 × 4 mm3). That is, the on-board printed antenna should have a small size for penta-band WWAN operation and can also be in close proximity to nearby system ground plane without affecting the antenna performances. In this paper, we present a promising small-size (15 × 25 mm2 or 375 mm2) on-board printed WWAN antenna to closely integrate with nearby system ground plane in the mobile phone. The antenna is a printed coupled-fed loop antenna, which shows a simple structure of comprising a 0.25- wavelength loop strip capacitively coupled by a feeding strip to cover the GSM850/900 operation. In addition, the feeding strip in the proposed antenna is also an efficient radiator to contribute a resonant mode to cover the GSM1800/1900/UMTS operation. That is, the proposed antenna can cover penta-band WWAN operation. Also, the protruded ground has a size of at least 10 × 15 mm2 to accommodate the associated electronic component such as a USB connector. The proposed antenna is fabricated and tested. The obtained results are presented. The antenna’s radiation characteristics including the SAR values for the antenna held by a hand phantom and attached onto a head phantom are also studied.