A 0.65 – 1 GHz tunable dual-band 4G-LTE antenna for carrier aggregation

This paper presents a tunable dual-band antenna using two different variable resonators for 4G carrier-aggregation applications. The antenna is fabricated on a PCB (RO4003C) with ε = 3.55 and Skywork's varactor diodes are used as variable capacitors. The first resonant frequency can be tuned independently from 0.65 GHz to 0.77 GHz while the second resonant frequency can be tuned from 0.78 GHz to 1 GHz, as shown by measurements. The simulated radiation efficiency of the antenna is 35% to 75% with a tuning element Q of 40 to 400, respectively. Gain measurements are currently being done and will be presented at the conference.