On-board 7-band WWAN/LTE antenna with small size and compact integration with nearby ground plane in the mobile phone

Abstract

A small-size on-board 7-band WWAN/LTE antenna formed by a coupled-fed loop antenna connected with a chip-inductor-loaded strip is presented. The antenna is disposed on a small board space of 15 × 25 mm2 (375 mm2) on the system circuit board and provides two wide operating bands to respectively cover GSM850/900 (824–960 MHz) and GSM1800/1900/UMTS/LTE2300/2500 (1710–2690 MHz) for the 7-band operation in the mobile phone. The antenna's upper band is contributed by the coupled-fed loop antenna operated at its 0.5-wavelength resonant mode. The generation of the lower band is owing to the chip-inductor-loaded strip connected to the coupled-fed loop antenna to form a coupled-fed shorted monopole antenna operated at its 0.25-wavelength resonant mode. In addition, the antenna's lower and upper bands can be respectively controlled, making it easy in fine-tuning the desired operating bandwidths in practical applications. Further, the proposed antenna can be in compact integration with its nearby ground plane on the system circuit board; that is, small isolation distance between the antenna and the nearby ground plane can be achieved for the proposed antenna. This leads to efficient board space planning on the system circuit board of the mobile phone. Details of the proposed antenna are described in the article. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2847–2853, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25619