Organic frequency doubler RFID tag exploiting 7.5-MHz wireless power transfer

In this article a paper-based contactless frequency doubler for harmonic RFID applications is described, fabricated and measured. The doubler, realized on paper substrate, generates the harmonic signal only by means of a Schottky diode. The fundamental and harmonic frequencies are wirelessly transferred to and from the doubler by coupled aerial resonators. The system operates at 7.5 and 15 MHz and these frequencies are chosen, without lack of generality, to accomplish for the future realization of a fully organic frequency doubler exploiting paper printed coils and organic diode (pentacene based), the present frequency limit of which is nowadays around 15 MHz. This perspective realization constrained also the geometry of the planar resonators that, although the diode at this level of the development is a conventional lumped one, are suited to host pentacene depositions and organic diode electrodes.