Multiband symmetrical slotted antennas for independent frequency tuning and wireless communication

Abstract It is proposed to use a triple-band, quatrefoil-shaped planar slotted monopole antenna that has independent frequency tuning and operates at 1.6, 2.4, and 5.6 GHz for wireless communication systems. To achieve the dual-band resonance, the antenna consists of four comparable circular slots etched on four additional symmetrical circular patches. For the third independent frequency band, the antenna uses an open-ended inverted L-slot on the feed line. The antenna peak gains of 2.8, 3.1, and 3.7 dB are obtained at matching frequencies, according to measured data. The feed-length variation-based dual-band slot antennas operating at UMTS2.1 GHz and Wi-Fi 2.45 GHz frequencies individually for radio frequency energy harvesting have been presented in this work. Besides, these antennas also provide wireless communication with the second band. The measured results of the proposed designs are compared with the corresponding simulation results. The parametric analysis of the simulated reflection coefficient has been performed at the different feed lengths of the two antennas. The gains of antennas are greater than 3.5 dBi and the radiation efficiency of the antenna is more than 71% obtained at the center frequency of all the operating bands.