Dual-Feed Shared-Radiator Metal-Frame Full-Screen Mobile Phone Antenna for GPS and LTE Bands With a Dual-Function Capacitor

A dual-feed shared-radiator metal-frame full-screen mobile phone antenna is proposed for the global positioning system (GPS) L5 band and the long-term evolution (LTE) bands in this communication. A symmetrical T-slot element and an asymmetrical T-slot element are first separately designed to cover the desired GPS and LTE bands, respectively. With the help of a capacitor, the two individual elements are merged to share a common radiator and are excited by dual coupling feeds. The capacitor has the dual functions of acting as a frequency-adaptive switch and miniaturizing the antenna. The proposed antenna occupies a small clearance area of only 46
$\times $
1 mm2. A prototype is fabricated and measured for verification. The experimental results illustrate that the −6 dB impedance operating band of the proposed antenna is 1172–1205 and 1410–2790 MHz, which can fully cover the GPS L5 band and the LTE B1/B2/B3/B32/B40/B41 bands with the isolation of better than 14.8 dB. The measured total efficiencies are 52.5%–63.9% for the GPS L5 band and 39.9%–61.5% for the LTE bands. With the merits of small clearance area, wide bandwidth, high isolation, and engineering feasibility due to the dual feeds, the proposed antenna is competitive for metal-frame full-screen mobile phones.