Reconfigurable antennas are very attractive for modern wireless communications because they allow the use of a single antenna for multiple systems. The research described in this project introduces the concept of reconfigurable antennas with switching beam control, operable at 5.8 GHz.
In this project, a new reconfigurable antenna design was proposed; namely a Reconfigurable Antenna Array (RAA). In the RAA configuration, the behavior of the reconfigurable multiple element linear antenna array system has been investigated with respect to the beam shaping characteristics. Two different beam patterns were achieved by reconfigure the number of patches element.
RAA for different area coverage
A completed project led by Mohd Tarmizi from Universiti Teknologi MARA presented a reconfigurable multiple element micro strip rectangular linear array antennas integrated with radio frequency (RF) switches. Reconfigurable beam shaping is ideal for the detection of small and large targets at both short and long ranges, including where the antenna is mounted on a high tower or hillside. “Reconfigurable antennas have been applied to many military and mobile communication applications where it is necessary to have a single antenna that can be dynamically reconfigured to transmit or receive on same or multiple frequency bands”, says Tarmizi. The development of a new and innovative antenna design is proposed which integrates RF switches to implement beam control in a reconfigurable antenna.
The team had to involve antenna design, fabrication and measurement in order to develop the optimum type of antenna. The objectives of the project were to study, design and fabricate an innovative RAA with respect of control of beam shape characteristics at a resonant frequency of 5.8GHz. Also to develop and design a Programmable Interface Controller (PIC) power microcontroller circuits that can be used to supply the DC voltage to activate the PIN Diode switch circuits. The simulated and measured results are presented and compared, to demonstrate the performance of the proposed antennas.
The team eventually succeeded in getting a simulation data to demonstrate the concepts of a reconfigurable number of elements that produced broadened beam and narrowed beam radiating pattern characteristics. By using a modified Wilkinson Power Divider (WPD) in the antenna structure, a better performance in terms of return loss was produced. This design solves some of the problems of the original Wilkinson power divider design. The addition of transmission lines in between two quarter-wave transformer arms has been shown to absorb an unwanted wave generated due to mismatch at the switches.
This research has taken advantage of the techniques of flexibly manipulating the number of elements by applying it to the problem of a reconfigurable multiple beam array combination. The reconfigurable dual-beam antenna pattern at fixed frequencies across the entire 5.7-5.9 GHz band is presented as showing excellent radiation patterns. The measured results illustrate that the radiation pattern characteristic of the antenna has been tuned efficiently. Since its structure is symmetrical around the centre, the pattern obtained is directed to è0. The reconfiguration of radiation patterns for four- and eight-element structures at 3 dB half power produced a beamwidth (HPBW) of 290 degrees and 210 degrees respectively. Meanwhile the return losses for both structures were -20.57 dB. The comparison of gain between both reconfigurable modes can be observed from the results: the eight-element mode had 2 dB to 3 dB higher gain compared to the four-element mode. It shows clearly that when the numbers of elements are increased, the beamwidth becomes narrower with lower sidelobe and higher magnitude.
In order to miniature the size of antenna design, the team has been plans to apply a Low Temperature Co-fired Ceramic (LTCC) substrate to replace with current substrate board in the near future.
Contact details of lead researcher(s)Dr Mohd Tarmizi Ali, Dr Azita Laily and Dr Norsuzila Ya’acob
Equipping form with function
23.06.2017 | Institute of Science and Technology Austria
Can we see monkeys from space? Emerging technologies to map biodiversity
23.06.2017 | Forschungsverbund Berlin e.V.
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology