Low background noise typically translates to better performance in electronics, such as longer ranges and clearer signals or higher information-carrying capacity. However, noise too low to measure means that circuit designers cannot tune the system for optimal performance. The NIST research focuses on CMOS (complementary metal oxide semiconductor) transistors, which are inexpensive and widely used in integrated circuits for wireless devices. Noise levels for CMOS transistors have, until now, been too low to measure accurately in much of their signal frequency range (1 – 10 gigahertz), and as a result CMOS circuits may be poorly matched to wireless transmission systems, resulting in significant signal loss.
In a collaboration with IBM Semiconductor Research and Development Center (Essex Junction, Vt.) and RF Micro Devices (Scotts Valley, Calif.), NIST has developed and demonstrated the capability to reliably measure the noise in CMOS devices before they are cut from silicon wafers and packaged. This is believed to be the first method for on-wafer noise measurements directly linked to national standards for thermal noise power. The new measurement methods were described June 12* at the IEEE Radio Frequency Integrated Circuits Symposium in San Francisco.
The team also demonstrated the use of "reverse" noise measurements--focusing on noise emitted from the input of the transistor when incoming signals are reflected and scattered--as a tool for checking overall noise parameters. This method can improve precision, particularly of the optimal impedance properties needed in transistors to minimize noise, the team found. Reverse noise measurements also may help improve modeling of CMOS transistors.
Laura Ost | EurekAlert!
Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent
25.09.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE
Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy