Low-profile, small-size, wireless wide area network handset antenna close integration with surrounding ground plane

An internal wireless wide area network (WWAN) handset antenna having a low profile of 3 mm, small footprint of 30 x 10 mm(2), and closely integrated with surrounding ground plane is presented.The antenna volume is 0.9 cm(3) only and can provide two wide-operating bands to cover the desired 824-960 and 1710-2170 MHz bands. The major portion of the antenna is printed on the main circuit board of the handset, and the antenna has a simple structure formed by a strip monopole and a parasitic shorted strip monopole. Two techniques are applied in the proposed design to achieve penta-band WWAN operation with a small antenna size. The first technique is to load a proper chip inductor at a proper position in the shorted strip monopole, which supports a resonant mode for the antenna's lower band with a resonant length much smaller than 0.25-wavelength. The second one is to use a band-stop matching circuit disposed on the main circuit board of the handset. The combined effects of the two techniques are discussed in this article. Also, the proposed antenna shows low near-field radiation characteristic and meets the specific absorption rate and hearing-aid compatibility requirements for practical handset applications. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:623-629, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26633