Creating and sharing knowledge for telecommunications

First demonstration of optical free space quantum communications in Portugal

on 18-07-2019

... The 180 meters between the 9th floor of the north and south towers of Instituto Superior Técnico (IST) were enough for IT to make history in Portuguese telecommunications. This July 8th the Physics of Information and Quantum Technologies (PIQT) group of IT in Lisbon did the first demonstration of quantum distribution of cryptographic key (QKD) via optical free space quantum communications in Portugal.

Quantum communications allow for a higher level of privacy than the currently existing with classical communications, and therefore have implications in the protection of our national sovereignty, the citizens, and the Portuguese companies. Quantum communications delivered through fiber optic cable are limited to about 200 km. Wireless communications via satellite, although incipient, are currently the solution for transmitting encrypted messages over long distances. In particular, it will be the way to establish quantum communications between Portugal´s mainland, Azores and Madeira, as well as the European quantum communications network that the Commission is launching, as well as with the rest of the world.

Present in this first demonstrations were Carole Mundell, Chief Scientific Adviser of the Foreign and Commonwealth Office of the United Kingdom, Christopher Sainty, British Ambassador in Portugal, Jürgen Mlynek, chair of the Strategic Advisory Board of the Flagship in Quantum Technologies European program, Carlos Salema, president of IT and the Academy of Sciences, Arlindo Oliveira, president of IST, among others.

Two days later, on the July 10th, a second demonstration took place during the closing session of the Ciência2019, at the invitation of Manuel Heitor, Portuguese Minister of Science, Technology and Higher Education. This second experiment, on stage, demonstrated the portability of the equipment and the technology outside the laboratory.

Through its coordinator Yasser Omar, PIQT is participating in the European project Quantum Internet Alliance. This project is part of Flagship in Quantum Technologies, a 10-year program with a budget of 1 billion Euro, which the Commission launched in 2018 to make Europe one of the world's leaders in quantum technologies.

Photo: The first experiment was carried out by Manfred Niehus (PIQT - IT/ISEL) and José Jesus, second year student of the MSc in Physics Engineering at IST and a fellow of the Gulbenkian program “New Talents in Quantum Technologies”. Credits: Débora Rodrigues / Técnico

μFlexBatt: Batteryless Energy Supply System based on Flexible Organic Photovoltaic Cells

on 17-07-2019

... The availability of ultra-low power (μW) and extremely complex integrated circuit functional blocks has been paving some recent research in human health monitoring. Wearable and implanted biomedical “smart” sensors (ECG, EEG, glucose, pH, temperature, etc.) are becoming available, in a single or network arrangement, including sensing, data processing and communication, for continuous check-up of health parameters. The power requirement of these portable health-monitoring systems depends on the application. In general, sensor nodes can consume less than 100 μW in normal operation mode.

Although these “smart” sensors are typically battery powered, it is well known that energy autonomy and battery lifetime can be improved by harvesting energy from several physical phenomena, like ambient light, vibration/motion of human body parts, temperature differences and RF electromagnetic radiation. Harvesting from the sun or ambient light is the most effective way to power a sensor node.

Funded and developed in IT, the ultimate objective of this project was to develop a batteryless energy supply system aimed at ultralow-power health-monitoring or IoT sensor nodes, composed of an organic photovoltaic cell as the energy harvesting device and a Power Management Unit (PMU) for voltage regulation, coupled as an ultra-compact (<1-2cm2) and flexible electrical energy supply system – the μFlexBatt.

Coordinated by Pedro Santos from the Wireless Circuits group of IT in Lisbon, this project comprised three main challenges: a) The development of organic photovoltaic (OPV) cells, with optimized power density of ca. 100 µW/cm2; b) The project of an ultra-compact (<5-10mm2) Power Management Unit (PMU), to convert the range of hundreds of mV delivered from the OPV to a regulated standard value (1.2V or 2.4V), either based on very-high switching frequency (<500MHz) fully CMOS (Complementary Metal Oxyde Semiconductor) or hybrid (with SMD) solution, or on very low form factor COTS (commercial off-the-shelf) SMD, in order to accomplish a low cost efficient circuit, with a footprint to fit the free area available outside the OPV active region; and Finally c) the assembly of the dedicated PMU on the OPV cell in an ultra-compact and flexible two-terminal battery like prototype – the μFlexBatt. The PMU footprint is to be placed over the OPV support area, outside the active area, in order to achieve maximum light conversion with optimized power density (work in progress). Seven PMU prototypes were studied, developed and successfully tested according to the project objectives

Photo: Printed circuit board of the commercial off-the-shelf Multilevel converter