A Transparent Double Folded Loop Antenna for IoT Applications

Wireless sensor devices are placed at various locations to suit each IoT application. In this study, we present a new transparent antenna for IoT applications. The proposed antenna has two advantages for wireless sensors. The first advantage is excellent visibility because the antenna is made with a transparent conductor. The second advantage is the low level of fluctuation in realized gain when the proposed antenna is in close proximity to metal. A distinctive feature of the structure of the proposed antenna is a double folded loop antenna (DFL). The DFL antenna has a double loop antenna(one wavelength) and connection points at a quarter wavelength from the feed point. These connection points form a folded loop structure. The realized gain of the proposed transparent antenna is 4 dB higher than that of a one-wavelength loop antenna when the antenna is in close proximity to metal. The proposed antenna allows placement at various locations for IoT applications. The antenna characteristics in the case of a copper pattern and transparent conductor are discussed in this paper.