Printed Fractal Folded Coplanar-strips-fed Array Rectenna for IoE Applications

Abstract

This paper presents a low-cost antenna integrable to a large set of indoor common building materials. Employing the printing technology on thin transparent polyethylene terephthalate material and using available building materials not only leads to a low-cost environmentally friendly solution for the expected massive sensor deployment but also eliminates the dispersive behavior of the materials that are interacting with them. A coplanar-strips fed fractal folded antenna element was designed and validated experimentally with four different materials including gypsum, plywood, and plexiglass. The aesthetically viable ground-free antenna achieves wideband performance and radiates in the broadside plane perpendicularly to the wall. The single antenna element covers the frequency band of 2.18-3.96 GHz with a gain of 1 dBi at 2.4 GHz. To take advantage of the large available surface, a high efficiency 2.4 GHz array rectenna for powering electronic devices intended for IoE technology is proposed. The proposed array rectenna has a dimension of 384 × 354 × 6.475 mm 3 and employs a single diode as the rectifier element. The measured results for the presented array rectenna reveal an AC-DC powerconversion-efficiency (PCE) of more than 20% for input powers as low as 0.025 µW/cm 2 with a peak PCE of 61.3% at 4.03 µW/cm 2 .

Reconfigurable screen-printed terahertz frequency selective surface based on metallic checkerboard pattern

“…FSS's pattern was printed upon a plastic substrate using silver ink utilizing a screen-printing technology (EKRA X1-SL Semi-Automatic Screen Printer) [36]. Though we have used a flat-bed screen printing system as a fabrication tool, both flexible and rigid substrates could be employed to print upon it.…”

“…To date, printed THz devices have been created exclusively through ink-jet printing, flexography, or hot stamping techniques. In contrast, the screen-printing method has been solely employed for the fabrication of devices within the microwave frequency range [34][35][36].…”