Topic Name: Researchers at Chalmers have succeeded in combining integrated receiver for high frequency applications
Research persons: Chalmers Research Team
Location: Chalmers University of Technology, Sweden
As the first research group in the world, researchers at Chalmers
have succeeded in combining a receiver for high frequencies with an antenna on a
The receiver is just a few square millimetre and is suitable for new safety
systems, image sensors, and radio communication for high bitrates. The receiver
is an electronic circuit including antenna, low noise amplifier, and frequency
converter monolithically integrated on gallium arsenide.
"This is a breakthrough in our research. Our result opens the
possibility to manufacture systems for very high frequencies within the so
called 'THZ-electronics' area, to a relatively low cost. In the next phase of
this project even more functions can be integrated on the same chip",
according to Herbert Zirath, professor at the department of Microwave
This circuit can for instance be used in radiometer systems in future safety
systems looking for concealed weapons without personal visitation. Other
applications for this circuit are imaging sensors that can look through
darkness, smoke or fog. This is an important safety function for vehicles such
as cars and aircrafts.
"Thanks to this technology, we now have the possibility of integrating
imaging sensors by using circuits of a few square millimetre which is much
smaller that the present technology at a lower cost. For automotive applications
such as cars, aircrafts and satellites, the size and weight is of utmost
importance. The present systems consist of many pieces and demands several cubic
decimetres volume", says Herbert Zirath.
The new circuit is designed to work at the frequency of 220 gigahertz, but
this is not an upper limit. According to professor Zirath, the technology can be
used up to and above 300GHz in a near future.
The technology is also interesting for wireless data communication because,
due to the very high bandwidth, data rate well above 10 Gbit/s is possible to
realize in future radio links. Together with Omnisys Instruments in Gothenburg,
we are also implementing receivers for future earth observation satellites for
environmental studies and weather forecasts at frequencies 118 and 183 GHz,
using the same technology.
Note for Image sensor
An image sensor is a device that converts a visual image to an electric signal. It is used chiefly in digital cameras and other imaging devices. It is usually an array of charge-coupled devices (CCD) or CMOS sensors such as active-pixel sensors.
There are several main types of color image sensors, differing by the means of the color separation mechanism:
Bayer sensor, low-cost and most common, using a Bayer filter that passes red, green, or blue light to selected pixels, forming interlaced grids sensitive to red, green, and blue. The image is then interpolated using a demosaicing algorithm.
Foveon X3 sensor, using an array of layered sensors where every pixel contains three stacked sensors sensitive to the individual colors.
3CCD, using three discrete image sensors, with the color separation done by a dichroic prism. Considered the best quality, and generally more expensive than single-CCD sensors.
Note for Low noise amplifier
The low noise amplifier (LNA) is a special type of electronic amplifier or amplifier used in communication systems to amplify very weak signals captured by an antenna. It is often located very close to the antenna. If the LNA is located close to the antenna, then losses in the feedline become less critical. This "active antenna" arrangement is frequently used in microwave systems like GPS, because coaxial cable feedline is very lossy at microwave frequencies.
It is a key component, which is placed at the front-end of a radio receiver circuit. Per Friis' formula, the overall noise figure of the receiver front-end is dominated by the first few stages.
Using a LNA, the noise of all the subsequent stages is reduced by the gain of the LNA and the noise of the LNA is injected directly into the received signal. Thus, it is necessary for a LNA to boost the desired signal power while adding as little noise and distortion as possible so that the retrieval of this signal is possible in the later stages in the system.
Note for Frequency converter
A frequency changer or frequency converter is an electronic device that converts alternating current (AC) of one frequency to alternating current of another frequency. The device may also change the voltage, but if it does, that is incidental to its principal purpose.
Traditionally, these devices were built out of electromechanical components such as motor-generator sets or rotary converters. But with the advent of solid state electronics, it has become possible to build completely electronic frequency changers. These devices usually consist of a rectifier stage (producing direct current) which is then inverted to produce ac of the desired frequency. The inverter may use thyristors or IGBTs. If voltage conversion is desired, a transformer will usually be included in either the ac input or output circuitry and this transformer may also provide galvanic isolation between the input and output ac circuits. A battery may also be added to the dc circuitry to improve the converter's ride-through of brief outages in the input power.
Professor Herbert Zirath, Microwave Electronics Laboratory, Department of
Micro technology and Nanoscience MC2, Chalmers University of Technology
Tel: +46 31-772 18 52
This work is the results of a co-operation between Chalmers, Saab Microwave
Systems, Omnisys Instruments AB, FOI, The Fraunhofer Institute IAF in Freiburg
and FGAN, Germany, within the project "nanoComp".
nanowire-based nanotechnology: sublithographic programmable logic arrays, 'Ferropaper' is new technology for small motors, robots, A Colossus Gets its Name, A research project on the next generation of smartphones, Air cooling of new computer chips, An intelligent cars, Angle-Resolved Photoelectron Spectroscopy, Atomic Clocks: a new generation of passive hydrogen maser, Base Transit Time of a Bipolar Transistor with Gaussian Base Doping Profile, Carnegie Mellon System Enables Any Digital Camera, Container protecting & navigating robots by sensing network, Electrically Measuring Method for a Quantum State of a Semiconductor Artificial Molecule : Applications in quantum information processing are expected, Electronic states of quantum dots, silicon atoms may shrink computers, Faster Graphene Transistors: Graphene circuits could lead to high-speed wireless devices and advanced weapons detectors., Flexible electronics with high-performance organic transistors., Flow specially of tiny bubbles specially microfluidic device mimics computer circuitry, Heat Resistant pressure sensors, High Speed Transfer Control layer Protocol development, How defects in the two-dimensional carbon crystal affect charge flow through the material, Important Milestone on the Way to the Setup of a New Standard for Capacitance using a Single-Electron Pump, Intruder alert: 'Smart Dew' will find you!, Lithography Past Light's Limits: A new optical etching technique could lead to faster microchips., Micro- and Nano- Systems Cluster, New Elastic circuit connectors designed for rubber-band-like circuits, New graphene transistor