Hybrid loop/monopole antenna with a passive bandstop circuit for the LTE/GPS operation in the tablet computer

A hybrid loop/monopole antenna capable of covering the LTE operation in the 698–960/1710–2690 MHz band and the GPS operation at 1575 MHz for the tablet computer application is presented. With the obtained LTE/GPS operation, the antenna requires a small size of 8 × 40 × 3 mm3 only. The antenna is operated as a coupled-fed loop antenna for the LTE operation and as a coupled-fed monopole antenna for the GPS operation. The two antenna structures share the same radiation strip, except that the loop antenna with the end terminal thereof short-circuited to the device ground plane of the tablet computer and the monopole antenna with the end terminal thereof open-ended. The two antenna structures are configured into one antenna structure using a passive bandstop circuit connected between the end terminal of the antenna's radiation strip and the device ground plane. The bandstop circuit exhibits a very high impedance in the GPS band and a very low impedance in the LTE band, thereby making the antenna operated as a loop antenna for the LTE operation (698–960/1710–2690 MHz) and a monopole antenna at 1575 MHz for the GPS operation. Details of the proposed hybrid loop/monopole antenna are described. Operating principle of the antenna is addressed, and experimental results of the fabricated antenna are presented and discussed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:630–635, 2016