Using optical fibre for the distribution of microwave signals has several benefits compared to using electrical cables. Optical fibre has low loss and frequency-independent attenuation. It is also insensitive to electromagnetic interference, low in weight, small in size and low in cost.
To meet the future demand generated by the constantly increasing number of devices that are wireless connected, and at the same time maintain full mobility and high data rates, new higher frequencies must be brought into use, as the frequency space is becoming congested.
In a new PhD thesis by Andreas Wiberg at the Photonics Laboratory at Chalmers, research is presented which deals with optical generation, modulation and distribution of signals in micro- and millimetre-wave applications. The results obtained include demonstrations of transportation of 40 GHz signals over 44 km of optical fibre modulated with 2.5 Gbit/s data, transmitted through a wireless link in a laboratory environment.
"Fibre optic solutions are particularly beneficial at high frequencies and over longer distances. Combining photonic technology and microwave applications opens up new, interesting possibilities and technical solutions," says Andreas Wiberg.
In order to also maintain sufficient coverage at high frequencies, new wireless systems with distributed antennas are required for both indoor and outdoor solutions. These antennas can be managed from a central location and with centralised control; dynamic channel allocation is possible in order to follow fluctuations in traffic load and maintain good wireless coverage.
Researchers at the Department of Microtechnology and Nanoscience at Chalmers University of Technology have investigated the possibility of using fibre optic technology to generate and distribute microwave signals for future networks with wireless Gigabit/s data rates, so-called Radio-over-Fibre.
The work by Andreas Wiberg also presents details of how several frequencies and/or frequency bands can be sent in parallel through a microwave photonic system in which optical filtering is used to separate the different frequencies. It is also shown that optical techniques could be used to generate high-frequency harmonics from electrically generated signals.
The use of photonic technology in microwave applications is referred to as Microwave Photonics and has many applications apart from communication. Microwave Photonics can also be used in analogue applications, such as reference signal generation and distribution of these signals to antenna arrays. Examples of such applications could be phase-steered radar antennas or large antenna arrays for radio astronomy.
Andreas Wiberg's thesis "Generation, Modulation, and Detection of Signals in Microwave Photonic Systems" will be defended in public on March 14, 2008.Time: 10 am
An abstract of the thesis is available in the Chalmers publication database, www.chalmers.seFor further information, please contact:
Sofie Hebrand | idw
Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences