Very-low-profile dual-wideband tablet device antenna for LTE/WWAN operation

Abstract

A simple two-strip antenna formed by a driven strip and a shorted parasitic strip to provide two wide bands with a very low profile of 8 mm for the LTE/WWAN operation (698–960/1710–2690 MHz) in the tablet devices such as a tablet computer is presented. In addition to the very low profile, the antenna occupies a small clearance region of 8 × 50 mm2 above the top edge of the device ground plane, and the thickness of the antenna is 3.8 mm only, which is promising for modern tablet device applications. The dual-wideband operation of the antenna is obtained by configuring the driven strip into a step shape, while the shorted parasitic strip includes a main segment and a double-step-shaped shorting segment. The proposed antenna configuration can lead to proper coupling between the driven strip and the parasitic strip, so that wideband resonant modes thereof can be generated, making the antenna's wide higher band cover the desired 1710–2690-MHz band. For the desired lower band of 698–960 MHz, it is achieved by integrating the driven strip with a high-pass matching circuit of a series chip capacitor of 1.8 pF and a parallel chip inductor of 13 nH, which does not increase the antenna's occupied volume and requires no realty space on the device ground plane. The integrated high-pass matching circuit greatly widens the antenna's lower band. Details of the proposed antenna are presented and discussed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1938–1942, 2014