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chapters:mttap:events2012 [2014/08/15 10:25] (current)
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 +====== Microwave Theory and Techniques Society/Antennas and Propagation Society event archive ======
 +===== 2012 Events =====
 +==== 23rd April====
 +=== ===
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 +**Seminar:** The History of Microwave Engineering in South East Queensland
 +**Speaker: Dr John Ness**, EM Solutions Pty Ltd
 +
 +**Location:** The University of Queensland
 +
 +**Abstract:** In 1987 a small team of researchers from the University of Queensland left to form a company called Mitec. 25 years later, Queensland is host to numerous microwave engineering companies spanning every aspect of the industry. Join us as Dr John Ness, Managing Director of EM Solutions and co-founder of Mitec, shares with us the history of microwave engineering in South East Queensland.
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 +
 +==== 30th May====
 +=== ===
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 +**Seminar:** Distinguished Lecturer: Development of the Dielectric Resonator Antenna
 +
 +**Speaker: Prof Kwok Wa Leung**, City University of Hong Kong (CUHK)
 +
 +**Location:** Queensland University of Technology
 +
 +**Abstract: ** The fundamentals and development of dielectric resonator antenna will be discussed in this talk. For many years, dielectric resonators (DRs) have only been used as high-Q elements in microwave circuits until S. A. Long and his collaborators showed that they can also be used as efficient radiators. The studies were motivated by an observation that carrier frequencies of modern wireless systems had gradually progressed upward to the millimeter-wave region, where efficiencies of metallic antennas can be reduced significantly due to the skin effect. In contrast, DR antennas (DRAs) are purely made of dielectric materials with no conductor loss. This feature makes DRAs very suitable for millimeter-wave systems.
 +
 +As compared to the microstrip antenna, the DRA has a much wider impedance bandwidth (~ 10 % for dielectric constant ~ 10). This is because the microstrip antenna radiates only through two narrow radiation slots, whereas the DRA radiates through the whole DRA surface except the grounded part. Avoidance of surface waves is another attractive advantage of the DRA over the microstrip antenna. Nevertheless, the DRA and microstrip antenna have many common characteristics because both of them are resonators. For example, both of them can be made smaller in size by increasing the dielectric constant because the dielectric wavelength is smaller than the free-space wavelength. Furthermore, basically all excitation methods applicable to the microstrip antenna can be used for the DRA.
 +
 +Although the DRA received attention originally for millimeter-wave applications, it is also widely investigated at microwave or even RF frequencies. It is because the DRA is a volume device that offers designers more degrees of freedom than 2D-type antennas (e.g., microstrip antennas) or 1D-type antennas (e.g., monopole antennas). Other advantages of the DRA include its light weight, low cost, low loss, and ease of excitation.
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 +
 +==== 10th September====
 +=== ===
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 +**Seminar: ** Small Antennas in Difficult Environments
 +
 +**Speaker: Prof David Thiele**, Griffith University
 +
 +**Location:** Griffith University, Nathan Campus
 +
 +**Abstract: ** Small wireless sensor nodes are often required to function in very difficult environments. These include: sensors on athletes (arms, legs, torso, costume etc.) and their equipment(bats, stick, racquet, oars, bikes etc), and sensors down drill holes and buried in the
 +earth. Common features are that these sensors need to be robust, waterproof and small so normal operations are not impeded.
 +
 +In these types of environment, there can be a significant shift in the antenna resonant frequency and one method of overcoming this is
 +to design antennas with large bandwidths. However, there are fundamental size limitations for antennas which are directly related
 +to bandwidth. This paper will outline some of the environmental problems and their solutions, the fundamental size limits as applied
 +to these sensor nodes, and some of the problems we are still trying to solve.
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 +
 +==== 17th September====
 +=== ===
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 +**Seminar:** Recent Advances in Coastal Surveillance by HF Surface Wave Radar in Germany
 +
 +**Speaker: Dr Thomas Fickenscher**, Germany
 +
 +**Location:** Griffith University, Nathan Campus
 +
 +**Abstract:** HF Surface Wave Radars (HF SWR) find applications in various fields such as oceanography, maritime surveillance, Tsunami warning or search and rescue operations. The radar group at Helmut Schmidt University / University of the Federal Armed Forces Hamburg is working in the field of coastal and mobile HF SWR since 2009. The primary obstacle to ship detection is first-order ocean clutter identified as so-called Bragg lines in the Range-Doppler map. Supported by the Bundeswehr Technical Centre for Ships and Naval Weapons (WTD 71) in Eckernförde new signal processing techniques for clutter suppression and enhanced ship detection have been developed and tested.
 +
 +This talk will provide first measurement results for a recently proposed new Sea Clutter Canceller Beamfomer which are presented in
 +comparison with results obtained with Chebychev beamformer. Furthermore, a detector based upon correlation of azimuth vectors
 +among neighbouring RD cells caused by spilling of target power will be presented.
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 +====== ======
 +<html><hr /></html>
 +  * <html><a class="lnk" onclick="newPage('mttap#past_events')">Microwave Theory and Techniques Society/Antennas and Propagation Society archive</a></html>
 +
 +  * <html><a class="lnk" onclick="newPage('oldchapters')">Chapters & Affinity Groups archive</a></html>
 +
 +  *<html><a class="lnk" onclick="newPage('./chapters:mttap:start')">Microwave Theory and Techniques Society/Antennas and Propagation Society chapter</a></html>
 
Last modified: 15 August, 2014