Nona-Band Antenna With Small Nonground Portion for Full-View Display Mobile Phones

A nona-band antenna with a small nonground portion for full-view display mobile phones is proposed. The width of the nonground portion is quite narrow at only 2 mm. This antenna consists mainly of two driven strips and two ground branches. An LC circuit is utilized to control the wave transmitted along the antenna and broaden the bandwidth. Then, three wide operating bands are generated by the proposed antenna to reach the desired low band (704-960 MHz), middle band (1710-2690 MHz), and high band (3300-3600 MHz). As a result, LTE700/GSM850/GSM900/GSM1800/GSM1900/UMTS/LTE2300/LTE2500 and a band for 5G can be covered simultaneously. An antenna prototype is fabricated and measured. The experimental results are in good agreement with the simulated results. The measured efficiencies are higher than 43%, 44%, and 52% in the low band, middle band, and high band, respectively. Reasonable radiation patterns and gains are also achieved.