Heptaband Inverted-F Antenna With Independent Resonance Control for Mobile Handset Applications

In this letter, a compact inverted-F antenna (IFA) with independent resonance control is presented. The proposed antenna covers the heptaband (GSM850/900/DCS/PCS/UMTS/LTE2300/2500) for mobile handset applications. The proposed structure consists of four radiating branches. Each branch operates at a quarter-wavelength mode as the fundamental resonant mode, and the proposed antenna has quintuple resonant frequency (f1, f2, f3, f4, and f5) characteristics. One remarkable feature of the proposed antenna is that each of the four resonant frequencies can be controlled independently without affecting the other four resonant frequencies (f5: harmonic of the fundamental frequency f1).