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
Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT
Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Power and Electrical Engineering
18.01.2017 | Materials Sciences
18.01.2017 | Life Sciences