Search results for "Impedance matching"
showing 4 items of 4 documents
Optimal matching between optical rectennas and harvester circuits
2017
This paper deals with optimal coupling issues between rectennas and harvesting circuits. An optical rectenna consists of a nanoantenna usually coupled with an ultra-high speed rectifier. These devices aim to receive and convert solar and thermal radiation in a DC voltage, while a harvester circuit provides the energy to be stored. The rectenna impedance is influenced both by its structure and by the rectifying diode, the harvester circuit impedance has to be matched to optimize the power transfer. The purpose of this contribution is to discuss the best impedance conditions by taking into account the constraints that are due to the individual devices the conversion system consist of. Finally…
Interface engineering for improved light transmittance through photonic crystal flat lenses
2010
In this paper, we present photonic crystal flat lenses with interfaces engineered to improve the light transmittance thanks to a broad angles impedance matching. The interface engineering consists in the realization of antireflection gratings on the edges of the lenses which are designed to reduce the propagative waves reflectivity over a wide range of incident angles. The fabricated structures were measured in optical near-field and a four times enhancement of the light transmission efficiency is reported.
Reconfigurable dualband antenna module with integrated high voltage charge pump and digital analog converter
2014
Integration of a reconfigurable antenna module for handheld applications employing a set of novel technologies is demonstrated. A low profile dualband hybrid dielectric resonator antenna (DRA) based on glass-ceramics and a tunable matching network (TMN) based on ferroelectric varactors with a maximum biasing of 90V form a reconfigurable antenna module. The control of the antenna module is performed by a 120V CMOS high voltage (HV) charge pump with an 8-bit digital analog (D/A) converter generated from a 3.7V battery. Adaptive impedance matching at the lower band of 1.9 GHz is carried out by the TMN when the dualband antenna is exposed to different operation scenarios. Meanwhile, the upper b…
Evaluation of an Optical Energy Harvester for SHM Application
2019
Abstract In this paper a preliminary study on an array configuration of rectified optical nanoantennas for energy harvesting application is proposed. Currently, the major impediments for the use of the rectified optical nanoantenna known as rectenna are the relatively low conversion efficiency and low power transfer to the load, both of them caused mainly by the mismatch between the impedance of the rectifier (several kilo ohms) and that of the antenna (hundreds of ohm). For this reason, the design of the array represents a crucial point to obtain the maximum energy transfer from the rectenna to the load, represented as a typical DC/DC boost power converter, and modeled by an equivalent inp…