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 mm 3 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.