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
New technology enables 5-D imaging in live animals, humans
16.01.2017 | University of Southern California
Fraunhofer FIT announces CloudTeams collaborative software development platform – join it for free
10.01.2017 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
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...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering