Summary
International Symposium on Antennas and Propagation
2008
Session Number:4IS06a
Session:
Number:4IS06a-4
GSM850/900/1800/1900/UMTS Printed Monopole Antenna for Mobile Phone Application
Ting-Wei Kang, Kin-Lu Wong,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
Owing to the rapid growth in mobile communications, the internal antenna for the mobile phone is generally required to be capable of multiband operation, especially penta-band operation covering GSM850/900/1800/1900/UMTS. However, owing to the limited space available inside the mobile phone, it is usually a big challenge for antenna engineers to achieve penta-bend operation for the internal mobile phone antenna with a small size. In this paper, we present a promising design of using a printed monopole antenna to achieve penta-band operation for the mobile phone. The proposed printed monopole antenna is to be printed directly on the system circuit board of the mobile phone, hence making it easy to fabricate at low cost. In addition, the printed monopole antenna is of low profile in appearance and thus especially suitable for application in a thin mobile phone [1, 2]. The proposed antenna also provides a promising solution for the printed monopole for internal mobile phone antenna applications to easily generate two wide operating bands for covering GSM850/900 and GSM1800/1900/UMTS operations. The proposed printed monopole shows a simple radiating metal pattern of a driven strip and a coupled strip. The enhanced bandwidth in the lower band at about 900 MHz is obtained by incorporating a high-pass matching network [3, 4] to the printed monopole, which results in a dualresonance excitation for the excited resonant mode in the lower band; this leads to a wide lower band for the antenna to cover GSM850/900 operation. On the other hand, the coupled strip can contribute an additional resonant mode for the antenna’s upper band to achieve a much widened bandwidth to cover GSM1800/1900/UMTS operation. In addition, since the coupled strip is excited through a small coupling gap by the driven strip [5], not through direct excitation as the traditional two-branch monopole antenna [6], its effects on the existing resonant modes contributed by the driven strip are found to be very small. This behavior makes the lower and upper bands of the proposed monopole antenna easy to be adjusted separately. This makes the antenna easy to design for practical applications. Details of the proposed printed monopole antenna for penta-band operation are presented.