Six-band internal antenna for small-size mobile phone

A promising six-band internal antenna suitable for small-size mobile phone application is presented. The mobile phone considered in this study has a system ground plane of length 60 mm only, much less than that of the general mobile phones. For such small-size mobile phones, it is not easy for the embedded antenna to achieve a wide operating band at 900 MHz for GSM850/900 operation. The proposed antenna solved the problem with a reasonable occupied volume. The antenna mainly comprises three radiating elements of two longer monopoles and a shorter monopole, which are configured to occupy a volume of 3.6 cm(3) only. The two longer monopoles incorporating an external parallel chip inductor lead to the successful excitation of a wide operating band for the antenna's lower band to cover GSM850/900 operation. Moreover, the three monopoles together contribute to the excitation of a very wide upper band to cover GSM1800/1900/UMTS/ WLAN operation. That is, the antenna can perform six-band operation for WWAN and WLAN communications. The proposed antenna is studied in detail in this article. (c) 2008 Wiley Periodicals, Inc.