Microscale Chiral Rectennas for Energy Harvesting.

Wireless radiofrequency rectifiers have the potential to power the billions of "Internet of Things" (IoT) devices currently in use by effectively harnessing ambient electromagnetic radiation. However, the current technology relies on the implementation of rectifiers based on Schottky diodes, which exhibit limited capabilities for high-frequency and low-power applications. Consequently, they require an antenna to capture the incoming signal and amplify the input power, thereby limiting the possibility of miniaturizing devices to the millimeter scale.

Tin Dioxide Thin Film with UV-enhanced Acetone Detection in Microwave Frequency Range.

In this paper, the UV illumination effect for microwave gas sensors based on the tin dioxide was verified. A UV LED with emission wavelength close to the absorption edge of the SnO gas-sensing layer was selected as the UV source. The developed gas sensors were tested under exposure to acetone in the 0-200 ppm range at room temperature.

Metal Oxide Thin Films Prepared by Magnetron Sputtering Technology for Volatile Organic Compound Detection in the Microwave Frequency Range.

Metal oxide thin films such as copper oxide, titanium dioxide, and tin dioxide deposited by magnetron sputtering technology were verified as a gas-sensitive layer in microwave-based gas sensors operated at 2.4 GHz. The developed gas sensors were tested at room temperature (23 °C) and 50% relative humidity (RH) under exposure to 0⁻200 ppm of selected volatile organic compounds (acetone, ethanol, and methanol) that are of high interest in industry and biomedical applications.

Rigorous Approach for Design of Differential Coupled-Line Directional Couplers Applicable in Integrated Circuits and Substrate-Embedded Networks.

We report rigorous approach for the design of differential coupled-line directional couplers in multilayer dielectric structures. In the proposed procedure numerically calculated per-unit-length parameters of coupled transmission lines are utilized for derivation of differential couplers' properties. The known description technique with multimode scattering parameters has been extended to the eight-ports considered in the paper and the properties resulting from symmetry of the considered networks have been shown.