Dual-inverted-F antenna with a decoupling chip inductor for the 3.6-GHz LTE operation in the tablet computer

ABSTRACT A simple, decoupled dual‐inverted‐F antenna (DIFA) formed by two inverted‐F antennas (IFAs) with a decoupling chip inductor is presented. The open ends of the two IFAs face to each other and are connected by the decoupling chip inductor. The DIFA has a planar structure and is easily fabricated on a thin dielectric substrate. Good isolation between the two IFAs can be obtained, owing to an equivalent bandstop circuit formed by the decoupling chip inductor and the equivalent distributed capacitor between the open ends of the two IFAs. For the tablet computer application in the 3.6‐GHz LTE band (3.4–3.8 GHz), the DIFA with a decoupling chip inductor of 39 nH occupies a small size of 20 × 4 mm2 on a 0.8‐mm thick FR4 substrate. The two IFAs in the DIFA almost require no isolation spacing, thereby leading to the compact structure and small size. Details of the proposed DIFA are described, and its multi‐input multioutput performance is discussed. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2189–2194, 2015