The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Scott A. Hamilton - One of the best experts on this subject based on the ideXlab platform.
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Optical Ground Terminals using multi-aperture digital coherent combining (Invited paper)
2017 IEEE Photonics Conference (IPC), 2017Co-Authors: David J. Geisler, Timothy M. Yarnall, Curt M Schieler, B. S. Robinson, M. L. Stevens, Scott A. HamiltonAbstract:We discuss an optical Ground Terminal receiver architecture based on multi-aperture digital coherent combining. Experimental results using four receivers demonstrate lossless coherent combining in the laboratory at power levels below 0.1 photons/bit/receiver, and mitigation of scintillation through a 3.2-km free-space link due to spatial diversity.
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Multi-aperture digital coherent combining for free-space optical communication receivers
Optics Express, 2016Co-Authors: David J. Geisler, Timothy M. Yarnall, Mark L. Stevens, Bryan S. Robinson, Curt M Schieler, Scott A. HamiltonAbstract:Space-to-Ground optical communication systems can benefit from reducing the size, weight, and power profiles of space Terminals. One way of reducing the required power-aperture product on a space platform is to implement effective, but costly, single-aperture Ground Terminals with large collection areas. In contrast, we present a Ground Terminal receiver architecture in which many small less-expensive apertures are efficiently combined to create a large effective aperture while maintaining excellent receiver sensitivity. This is accomplished via coherent detection behind each aperture followed by digitization. The digitized signals are then combined in a digital signal processing chain. Experimental results demonstrate lossless coherent combining of four lasercom signals, at power levels below 0.1 photons/bit/aperture.
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Multi-aperture digital coherent combining for next-generation optical communication receivers
2015 IEEE International Conference on Space Optical Systems and Applications (ICSOS), 2015Co-Authors: Timothy M. Yarnall, David J. Geisler, Mark L. Stevens, Bryan S. Robinson, Curt M Schieler, Scott A. HamiltonAbstract:Space Terminals for free-space optical communication systems are under constant pressure to reduce their size, weight, and power profiles. Ground Terminals with large collection areas are costly, but provide a means to reduce the aperture-power product on a space platform required to close a given link. We present a Ground Terminal receiver architecture in which many small apertures are coherently combined while maintaining excellent receiver sensitivity. This is accomplished via coherent detection behind each aperture followed by digitization. The digitized signals are then combined in a digital signal processing chain. Experimental results demonstrate lossless coherent combining of low-flux lasercom signals.
A. Sabban - One of the best experts on this subject based on the ideXlab platform.
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Ka-band compact integrated high power amplifiers for VSAT satellite communication Ground Terminal
2000 Asia-Pacific Microwave Conference. Proceedings (Cat. No.00TH8522), 2000Co-Authors: A. SabbanAbstract:This paper describes the design and performance of new compact and low cost Ka-band power amplifiers. The main features of the power amplifiers are: 27 dBm to 35 dBm minimum output power for -16 dBm input power over the frequency range of 27.5-31 GHz. To reduce losses MIC, MMIC and waveguide technologies are employed in the development and fabrication of this set of power amplifiers. Employing waveguide technology has minimized losses in the power combiner. Three power amplifiers are described in this paper. The first amplifier is a 0.5 W power amplifier, the second is a 1.5 W power amplifier, and the third amplifier is a 3.2 W power amplifier.
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A Ka-Band Compact Integrated Transmitter for VSAT Satellite Communication Ground Terminal
1997 27th European Microwave Conference, 1997Co-Authors: A. Sabban, A. Madjar, I. Shapir, D. BeharAbstract:This paper describes the design and performance of a new compact and low cost Transmitter for Ka band VSAT satellite communication Ground Terminal. The main features of the transmitter are: 32.5dBm minimum output power for -16 dBm input power over the frequency range of 27.5-31GHz. The Transmitter consists of low power MMIC amplifier, band pass filter, a medium power MMIC amplifier, a four way microstrip power divider, a high power module with four MMIC power amplifiers, a four way waveguide power combiner and DC supply unit. The Transmitter size is 15.5×11×2.5 cm and weighs less than 0.6 Kg.
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Development and Fabrication of a Compact Integrated RF-Head for Inmarsat-M Ground Terminal
1997 27th European Microwave Conference, 1997Co-Authors: A. Sabban, A Britebard, Y ShemeshAbstract:This paper describes the design, performance and fabrication of a compact and low cost RF-Head for Inmarsat-M applications. The RF-Head is part of a portable satellite communication Terminal called "Caryphone". "Caryphone" supplies phone and fax services to the customer. The "Caryphone" Terminal has been approved by Inmarsat on Augrust 1995. Up to date around 300 Terminals have been manufactured. The RF-Head includes a receiving and transmitting channels, receiving and transmitting synthesizers, RF-Controller, Modem and a DC supply unit. The RF-Head size is 30×20X2.5 cm and weighs less than 1 Kg. The transmitting channel may be operated in high power mode or in low power mode to transmit 10W or 4W respectively. The output power level and the RF-Head vent is automatically controlled by the RF controller The noise figure of the receiving channel is better than 2.2 dB including 1dB diplexer losses The total gain of the receiving channel is 76dB. Surface Mount Technology is employed to fabricate the RF-Head.
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A compact low power consumption integrated RF-head for Inmarsat-M Ground Terminal
1995 25th European Microwave Conference, 1995Co-Authors: A. Sabban, Y Shemesh, A BritebardAbstract:This paper describes the design and performance of a compact and low cost RF-Head for Inmarsat-M applications. The RF-Head is part of a portable satellite communication Terminal called "BIPSAPHONE". BIPSAPHONE supplies phone and fax services to the customer. The RF-Head includes a receiving and transmitting channels, receiving and transmitting synthesizers, RF-Controller and a DC supply unit. The RF-Head size is 30×20×2.5 cm and weight less than lKg. The transmitting channel may be operated in high power mode or in low power mode to transmit 10W Or 4W respectively. The output power level is automatically controlled by the RF controller. The noise figure of the receiving channel is better than 2.2 dB including 1 dB diplexer losses. The total gain of the receiving channel is 75dB.
Giovanni Toso - One of the best experts on this subject based on the ideXlab platform.
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a dual frequency ka band printed fresnel reflector for Ground Terminal applications
IEEE Transactions on Antennas and Propagation, 2015Co-Authors: J M Baracco, Philippe Ratajczak, Patrice Brachat, Giovanni TosoAbstract:Satellite-based telecommunication systems operating in Ka-band require high gain Ground Terminal antennas. A promising architecture based on dual frequency printed Fresnel reflectors is presented in this paper. The complete development of this antenna including its design methodology, manufacturing, and testing is described. In order to scan its beam, the proposed antenna system can either be combined with electric motors or be transformed into a reconfigurable reflectarray system by replacing the passive reflecting cells by reconfigurable ones. A possible way of implementing such electronically reconfigurable reflecting cells is also presented.
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Dual frequency Ka-band reflectarray for Ground Terminal application
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014Co-Authors: J M Baracco, Philippe Ratajczak, Patrice Brachat, Giovanni TosoAbstract:In its first part, this paper presents the design and testing of a passive dual frequency printed Fresnel reflector which could be used as Ground Terminal for Ka-band satellite telecommunication applications. In the second part of the paper, the structure and the performances of an active dual frequency reflecting cell allowing to transform the initial passive antenna into an active reflectarray, are presented.
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Dual frequency Ka-band Fresnel reflectors
2011 IEEE International Symposium on Antennas and Propagation (APSURSI), 2011Co-Authors: J M Baracco, Philippe Ratajczak, Patrice Brachat, Giovanni TosoAbstract:This paper presents the first results in the development of a dual frequency Fresnel reflector which could be used as Ground Terminal for wideband telecommunication satellite systems operating at Ka-band.
Edwin K. P. Chong - One of the best experts on this subject based on the ideXlab platform.
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Systems Engineering of a Terabit Elliptic Orbit Satellite and Phased Array Ground Station for IoT Connectivity and Consumer Internet Access
IEEE Access, 2016Co-Authors: Rick L. Sturdivant, Edwin K. P. ChongAbstract:Systems engineering of a satellite based data communication baseline concept is presented to achieve terabit per second throughput. It uses a constellation of five Molniya satellites and one dimension electronic scanning phased array Ground Terminals. The result is a baseline concept that meets customer needs for internet of things (IoT) data connectivity and for consumer high data rate internet access. Molniya orbit satellites provide the benefits of available bandwidth, lack of interference with other satellite links, and less crowded orbital paths. A drawback is that they are not geostationary since they have highly elliptical orbits. This requires Ground station Terminals with the ability track the satellites as they pass overhead during their orbit. However, since Molniya satellites with a properly selected eccentricity pass along the same path at nearly constant elevations relative to a fixed position on the Earth, simple and low-cost single axis scanning antennas can be used for the consumer Ground Terminal. This is a distinct advantage compared with competing low earth orbit constellations. The proposed solution leverages advances in semiconductor technology and low-cost antenna laminate substrate materials for an affordable phased array tracking Ground Terminal antenna. This paper presents link budget trade studies, system concept, orbital dynamics simulation results, and Ground station component trade study.
David J. Geisler - One of the best experts on this subject based on the ideXlab platform.
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Optical Ground Terminals using multi-aperture digital coherent combining (Invited paper)
2017 IEEE Photonics Conference (IPC), 2017Co-Authors: David J. Geisler, Timothy M. Yarnall, Curt M Schieler, B. S. Robinson, M. L. Stevens, Scott A. HamiltonAbstract:We discuss an optical Ground Terminal receiver architecture based on multi-aperture digital coherent combining. Experimental results using four receivers demonstrate lossless coherent combining in the laboratory at power levels below 0.1 photons/bit/receiver, and mitigation of scintillation through a 3.2-km free-space link due to spatial diversity.
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Multi-aperture digital coherent combining for free-space optical communication receivers
Optics Express, 2016Co-Authors: David J. Geisler, Timothy M. Yarnall, Mark L. Stevens, Bryan S. Robinson, Curt M Schieler, Scott A. HamiltonAbstract:Space-to-Ground optical communication systems can benefit from reducing the size, weight, and power profiles of space Terminals. One way of reducing the required power-aperture product on a space platform is to implement effective, but costly, single-aperture Ground Terminals with large collection areas. In contrast, we present a Ground Terminal receiver architecture in which many small less-expensive apertures are efficiently combined to create a large effective aperture while maintaining excellent receiver sensitivity. This is accomplished via coherent detection behind each aperture followed by digitization. The digitized signals are then combined in a digital signal processing chain. Experimental results demonstrate lossless coherent combining of four lasercom signals, at power levels below 0.1 photons/bit/aperture.
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Multi-aperture digital coherent combining for next-generation optical communication receivers
2015 IEEE International Conference on Space Optical Systems and Applications (ICSOS), 2015Co-Authors: Timothy M. Yarnall, David J. Geisler, Mark L. Stevens, Bryan S. Robinson, Curt M Schieler, Scott A. HamiltonAbstract:Space Terminals for free-space optical communication systems are under constant pressure to reduce their size, weight, and power profiles. Ground Terminals with large collection areas are costly, but provide a means to reduce the aperture-power product on a space platform required to close a given link. We present a Ground Terminal receiver architecture in which many small apertures are coherently combined while maintaining excellent receiver sensitivity. This is accomplished via coherent detection behind each aperture followed by digitization. The digitized signals are then combined in a digital signal processing chain. Experimental results demonstrate lossless coherent combining of low-flux lasercom signals.
