A Novel Dual-Band WIFI Antenna with Frequency-Reconfigurability

This paper presents a novel dual-band WIFI antenna with frequency-reconfigurability by utilizing a capacitor. The higher band is mainly contributed by a monopole and the lower band is jointly inspired by the monopole and the capacity loaded floating branch. The dual-band antenna without lumped capacity has 112 MHz (2.374 GHz-2.486 GHz) and 1.026 GHz (4.678 GHz-5.704 GHz) -10 dB ( |S11|) bandwidth, for low and high bands, respectively. By introducing a tunable capacity, low-band frequency could be reconfigured and the antenna size can be further reduced. The measured radiation efficiency for the low-and high-band is above 70% and 90%, respectively.