We present the design and performance of a state-of-the-art broadband (60 to 90 GHz, 40%) millimeter-wave FET asymmetrical switch, realized in a metamorphic high electron mobility transistor (mHEMT) technology. The sw...
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We present the design and performance of a state-of-the-art broadband (60 to 90 GHz, 40%) millimeter-wave FET asymmetrical switch, realized in a metamorphic high electron mobility transistor (mHEMT) technology. The switch is dedicated to wireless communication or radiometry applications. It makes use of a single control voltage which simultaneously toggles between states. The two signal paths are asymmetrical, one using a series FET, the other a shunt-FET, and exhibit insertion losses of 2.8 and 1.7 dB, respectively. Broadband operation is achieved by introduction of matching stubs at each switch branch input.
Environment awareness through advanced sensing systems is a major requirement for a mobile robot to operate safely, particularly when the environment is unstructured, as in an outdoor setting. In this paper, a multi-s...
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Environment awareness through advanced sensing systems is a major requirement for a mobile robot to operate safely, particularly when the environment is unstructured, as in an outdoor setting. In this paper, a multi-sensory approach is proposed for automatic traversable ground detection using 3D range sensors. Specifically, two classifiers are presented, one based on laser data and one based on stereovision. Both classifiers rely on a self-learning scheme to detect the general class of ground and feature two main stages: an adaptive training stage and a classification stage. In the training stage, the classifier learns to associate geometric appearance of 3D data with class labels. Then, it makes predictions based on past observations. The output obtained from the single-sensor classifiers is statistically combined exploiting their individual advantages in order to reach an overall better performance than could be achieved by using each of them separately. Experimental results, obtained with a test bed platform operating in a rural environment, are presented to validate this approach, showing its effectiveness for autonomous safe navigation.
Upconversion (UC) materials, which are able to emit higher-energy light after the absorption of two or more lower-energy photons, have regained attention due to their potential to enhance the efficiency of solar cells...
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Upconversion (UC) materials, which are able to emit higher-energy light after the absorption of two or more lower-energy photons, have regained attention due to their potential to enhance the efficiency of solar cells. In particular, for crystalline silicon solar cells, around 32% of the incident solar light is lost due to photons with energy below the bandgap (E g =1.1 eV, 1100 nm) [1]. The main
Existing SAR systems are often limited in resolution by their small bandwidth of below 10 GHz. In this contribution an ultra-wideband 80 GHz FMCW radar sensor for SAR imaging with 25.6 GHz bandwidth is presented. It i...
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Existing SAR systems are often limited in resolution by their small bandwidth of below 10 GHz. In this contribution an ultra-wideband 80 GHz FMCW radar sensor for SAR imaging with 25.6 GHz bandwidth is presented. It is based on a custom low-power SiGe-MMIC including all high frequency components, using a nested PLL concept in combination with off-the-shelf PLL synthesizer ICs. In single direction radar measurments, a resolution of 8.09mm is shown. Additionally, results of SAR measurements with a point target show that a good spatial resolution of 12.0 mm × 8.1 mm (Tukey window, α = 0.25, -6 dB width) is achieved. Furthermore, high resolution SAR images of a bike acquired with the sensor are presented.
Nowadays, we cannot imagine our life without video content and without devices that enable us to acquire and display such content. According to recent research, in 2012, the video content transfer over the Internet wa...
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Nowadays, we cannot imagine our life without video content and without devices that enable us to acquire and display such content. According to recent research, in 2012, the video content transfer over the Internet was around 60% of the overall Internet data transfer, and the overall video transfer (including the Internet) could reach 90% during the next four years. The TV sets supporting only full high-definition (HD) resolution (i.e., 1080p) are already considered to be outdated due to a dramatic demand for the ultra-HD resolution that often refers to 3840×2160 (4K) or 7680×4320 (8K) resolutions. So, what are the key factors for such tremendous progress? If you are reading this special section on video compression technology, we are sure that you know the answer…
In this paper we describe our methodology for building context-aware applications. It supports a systematic definition, conception and development of the context-aware features of an application along the different ph...
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Current logistic IT systems tend to be monolithic applications with low flexibility and low awareness of interoperability. Modern IT trends like Service Oriented Architectures and Cloud Computing are key factors to pr...
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ISBN:
(纸本)9781629934853
Current logistic IT systems tend to be monolithic applications with low flexibility and low awareness of interoperability. Modern IT trends like Service Oriented Architectures and Cloud Computing are key factors to provide convenient access to customized IT-Services on demand and as a service. Hence, the idea of the concept Logistics as a Service is to provide domain specific IT services to support the planning and operations in supply chains which are supported by infrastructural technologies. In this paper, the general concepts behind Logistics as a Service as well as exemplary IT services are presented and proven to be applicable by demonstration of several use cases. Logistics as a Service is one leading topic in the EffizienzCluster LogistikRuhr (EfficiencyCluster LogisticsRuhr) and therefore part of the German High Tech Strategy.
Advanced systems for harvesting sub-bandgap photons via upconversion were investigated, comprising improved upconverter materials, adapted silicon solar cells, nanocrystalline quantum dots and spectrally selective pho...
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High-speed electronic integrated circuits are essential to the development of new fiber-optic communication systems. Close integration and co-design of photonic and electronic devices are becoming more and more a nece...
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ISBN:
(纸本)9781849197595
High-speed electronic integrated circuits are essential to the development of new fiber-optic communication systems. Close integration and co-design of photonic and electronic devices are becoming more and more a necessity to realize the best performance trade-offs. This paper presents our most recent results and a brief introduction to our research in recently started EU projects.
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