A Highly Compact and Low Cost UHF Wide Slot Antenna for Internet of a Things Applications

Recently, there are many investigations on communication technology to be applied for a long range communication with low consumption of power for Internet of Things (IoT). This paper proposed a highly compact and cheap planar antenna that covers the UHF band (892–940) MHz with a relatively high gain value. The total size of the proposed antenna is 55 × 60 × 1.6 mm 3 fabricated on a low-cost FR4 dielectric substrate. It consists of a tuning stub with feeder line on the upper side of the dielectric substrate and a rectangular wide slot engraved on the other side of the substrate. The shape of the tuning stub has been selected in such a way that guarantees a strong coupling between the wide slot and the feed line. In spite of the antenna compact size, reasonable simulated and measured gain values of 2.02 dBi and 1.76 dBi respectively are obtained at a resonance frequency of 915 MHz with omnidirectional radiation pattern that is independent of the orientation of the IoT device. The simulated and measured reflection coefficient results exhibit good impedance matching at the resonance frequency with less than −20 dB and −16 dB respectively. The simulated and measured −10 dB bandwidth values are found as 48 MHz and 65 MHz respectively.