Development of Phased Array of Switched Beam Elements
Speaker: Prof Monai Krairiksh, King Mongkut's Institute of Technology Ladkrabang
When: 2004-10-06 16:00:00
Venue: 78-420
Host: Prof Marek Bialkowski (ITEE)/Dr Ashley Robinson (IEEE)
Abstract:In modern wireless communication systems, the performance of the
system is seriously degraded by multipath fading and co-channel
interference. The multipath fading is caused by the different path
lengths with different arrival angles that arise from the
transmitted signal impinging on objects in the environment, while
the co-channel interference is experienced as the undesired signal
with co-channel frequency from other base stations or user
terminals. A phased array antenna of switched-beam elements is
proposed to increase the signal-to-interference ratio of the
wireless communication system by introducing more capability in
suppressing the interference than that of the conventional
switched-beam antenna. The proposed array antenna offers not only
the switchable main beam to track the desired user but also the
changeable null pattern to suppress the interference. By using the
switched-beam element, the null pattern of the array is varied by
switching the beam of element, and the main beam of the array is
switched by using 1-bit phase shifters. The four-beam phased array
antenna with changeable null pattern is designed and
implemented. The design and characteristics of the switched-beam
element, 1-bit phase shifter and the array antenna are
shown. Subsequently, the performance on signal-to-interference ratio
improvement is investigated in multipath environment. The
measurement setup and results are discussed. The results of
radiation patterns show that the changeable null pattern is useful
for eliminating the interference. It is found that the SIR is
significantly affected by the multipath environment; however, the
performance improvement in the multipath environment can be obtained
by the changeable null pattern.
Biography:Dr. Monai Krairiksh gained Bachelor, Master and Doctor of
Engineering degrees from King Mongkut's Institute of Technology
Ladkrabang (KMITL). He is currently a Professor at the Department of
Telecommunication Engineering, KMITL. He has served as a Director of
Research Center for Communications and Information Technology
(ReCCIT) during 1997-2002. His research interests include antennas
for mobile communications and microwave applications.
Type: IEEE MTT/AP Queensland Chapter
Contact:Prof Marek Bialkowski (ITEE)/Dr Ashley Robinson (IEEE), seminar host (meb@itee.uq.edu.au)
or Guido Governatori (ITEE seminar co-ordinator)
(guido@itee.uq.edu.au)