To demonstrate and investigate the possibilities of active antennas with digital beamforming, a compact breadboard model operating in C-band with planar patches as radiators is fabricated and ...measured. It was originally designed as a technology demonstrator for navigation purposes, but will be extended for future use in combined navigation and communication systems. Several parameters for beam position, sidelobe reduction, and nulling are set and controlled by a suitable user interface. A special calibration and error-correction procedure is developed to compensate for drift of active elements, mutual coupling of the patches, and finite-ground plane effects. The excellent results demonstrate the versatile features of digital beamforming for satellite navigation and communication systems.
Many pattern recognition problems can be solved by mapping the input data into an n-dimensional feature space in which a vector indicates a set of attributes. One powerful pattern recognition method ...is the Hough transform. In reducing the n-dimensional feature space to two dimensions, the coordinate transform can be executed by a systolic array consisting of time-delay processing elements and adders. The application-specific integrated circuit (ASIC) implementation of the Hough transform as a systolic array for real-time recognition of curved tracks in multiwire drift chambers is presented. The array can handle 32 parallel input data streams. It mainly consists of 512 identical programmable processing elements. Sixteen histogram pixels in the feature space are produced in parallel per clock cycle. The ASIC is implemented in 0.6 /spl mu/m CMOS, two-metal layer technology (CUB) from Austria Micro Systems (AMS) and operates with a clock frequency of 100 MHz. The interconnectivity pattern of the processing elements required to initialize the chip according to the pattern recognition task is computed on the host computer using the Hough-transform equations. This pattern is then downloaded to the chip via the data input lines. The Hough-transform ASIC is suitable for a wide range of pattern recognition applications. The integrated circuit is a powerful building block for systems requiring real-time execution of the Hough transform.
The HERA-B vertex detector system Bauer, C.; Bräuer, M.; Glebe, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2000, Letnik:
453, Številka:
1
Journal Article
Recenzirano
The HERA-B experiment is being built to measure CP violation in the B-system using internal targets at the HERA proton storage ring at DESY. This paper presents an overview of its vertex detector ...which – apart from an additional superlayer – is realized by a system of 20 Roman pots containing seven superlayers of double-sided silicon microstrip detectors that are operated at 10 mm distance from the proton beam in a high-radiation environment.
This paper presents the design and development of a wideband dual polarized planar array antenna of 4 × 6 elements in C-band with a centre frequency of 5.3 GHz. The radiating element is of stacked ...strip slot foam inverted patch (SSFIP) configuration. The complex excitation coefficients of the antenna have been chosen in order to achieve a fixed beam-pointing by 10° and side-lobe level better than −15 dB. The array antenna offers a VSWR bandwidth of 20% for a VSWR ratio of 2:1. The simulated and measured antenna parameters are presented.
First experience and results from the HERA- B vertex detector system Bauer, C.; Baumann, I.; Bräuer, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/1998, Letnik:
418, Številka:
1
Journal Article
Recenzirano
The HERA-
B collaboration is building a detector to realize the ambitious goal of observing CP violation in decays of neutral B-mesons. A central element of the apparatus is the silicon vertex ...detector used to selectively trigger on these decays in a high charged particle multiplicity background environment and to reconstruct secondary vertices from such decays with high precision. The vertex detector, the supporting infrastructure and first results using prototype detectors are described. Results include imaging of the proton interaction region on the HERA-
B target, hit distributions in the detector planes, and alignment of the detectors with each other and the target.
Real-time calibration-free autonomous eye tracker Klefenz, F; Husar, P; Krenzer, D ...
2010 IEEE International Conference on Acoustics, Speech and Signal Processing,
2010-March
Conference Proceeding
In several fields of medicine, transportation and security the instantaneous gaze direction of a person under supervision is of crucial importance. We developed a contactless stereoscopic video-based ...eye tracker which works without any individual calibration. In real time it delivers information about the gaze direction frame by frame. The introduced algorithms are designed for computing the gaze direction within image acquisition time that is only limited by the hardware setup. The cameras are integrated into front-end modules by means of FPGA (programmable logic) circuits for image processing. Computation of the gaze direction is based on the spatial position of the pupil which is detected by a five-dimensional Hough transform. The system works under ambient light conditions whereas additional infrared illumination can be used to become independent of ambient light.
Viasat invested in the past years essential effort to develop airborne and land-mobile user terminals, suitable for future GSO (Geostationary Orbit) and new upcoming NGSO (Non-Geostationary Satellite ...Orbit) connectivity demands. The electronical steerable antenna approach is based on a phased array technology, composed of a custom printed circuit board equipped with a proprietary RFIC. The same building blocks of this array have been successfully used across the different markets. We intent, with this paper, to gives a summary of the main design features and an overview of the antenna performance and results achieved on first flight tests.
A planar digital-beamforming (DBF) antenna for user terminals in future satellite navigation systems has been developed to improve the overall system performance. A C-band breadboard model including ...aperture coupled patches, receiver and signal-processing unit has been designed, manufactured and tested.
PDF
