WWAN/LTE Handset Antenna with Shaped Circuit Board, Battery, and Metal Midplate

An onboard printed WWAN/LTE antenna of simple structure disposed in a small clearance of 8 3 36 mm 2 in the ground plane of shaped circuit board in a slim handset is presented. The shaped circuit board has a large rectangular notch such that the battery of the handset can be embedded therein to decrease the thickness of the handset. It is shown that, compared to the traditional simple circuit board, the shaped circuit board can lead to much enhanced bandwidth of the antenna disposed thereon. This is mainly because stronger surface currents on the ground plane of the shaped circuit board can be excited, which greatly helps improve the operating bandwidth of the antenna disposed thereon. By properly short-circuiting the metal enclosing of the battery and the metal midplate that can be used to provide the handset with structural support, stronger excited surface currents on the ground plane of shaped circuit board can still be obtained. The proposed design makes a simple, small-size printed inverted-F antenna capable of providing two wide operating bands to cover the GSM850/900 bands (824-960 MHz) and GSM1800/1900/UMTS/LTE2300/2500 bands (1710-2690 MHz). Further, the proposed design can provide good antenna efficiency and meet the specific absorption rate regulations of less than 1.6 W/kg for 1-g head tissue as well. Detailed results of the proposed design are presented and discussed. (C) 2013 Wiley Periodicals, Inc.