POLARIS: ESA's airborne ice sounding radar front-end design, performance assessment and first results
ABSTRACT This paper addresses the design, implementation and experimental performance assessment of the RF front-end of an airborne P-band ice sounding radar. The ice sounder design comprises commercial-of-the-shelf modules and newly purpose-built components at a centre frequency of 435 MHz with 20% relative bandwidth. The transmitter uses two amplifiers combined in parallel to generate more than >128 W peak power, with system >60% PAE and 47 dB in-band to out-of-band signal ratio. The four channel receiver features digitally controlled variable gain to achieve more than 100 dB dynamic range, 2.4 dB noise figure, 160 ns receiver recovery time and -46 dBc 3rd order IMD products. The system comprises also, a digital front-end, a digital signal generator, a microstrip antenna array and a control unit. All the subsystems were integrated, certified and functionally tested, and in May 2008 a successful proof-of-concept campaign was organized in Greenland. The system detected the bedrock under 3 km of ice, and internal layers were mapped up to 1.3 km.
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ABSTRACT: An improved lumped-distributed planar 3 dB Wilkinson divider is presented. The technique reduces the number of components and via-grounds. An analysis based on ideal transmission lines provides design equations for the proposed Wilkinson divider. The topology gives good results at L-band and uses less than half of the substrate area of the standard topologyElectronics Letters 05/2001; 37(8-37):501 - 503. DOI:10.1049/el:20010356 · 1.07 Impact Factor
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ABSTRACT: EMISAR is a high-resolution (2×2 m), fully polarimetric, dual-frequency (L- and C-band) synthetic aperture radar (SAR) system designed for remote-sensing applications. The SAR is operated at high altitudes on a Gulfstream G-3 jet aircraft. The system is very well calibrated and has low sidelobes and low cross-polar contamination. Digital technology has been utilized to realize a flexible and highly stable radar with variable resolution, swath width, and imaging geometry. Thermal control and several calibration loops have been built into the system to ensure system stability and absolute calibration. Accurately measured antenna gains and radiation patterns are included in the calibration. The processing system is developed to support data calibration, which is the key to most of the current applications. Recent interferometric enhancements are important for many scientific applicationsIEEE Transactions on Geoscience and Remote Sensing 12/1998; 36(6-36):1852 - 1865. DOI:10.1109/36.729356 · 2.93 Impact Factor
Conference Paper: Development of an airborne ice sounding radar front-end[Show abstract] [Hide abstract]
ABSTRACT: This paper describes the design of an airborne P-band ice sounding radar. The ice sounder design features a microstrip antenna array with a relative operating bandwidth of 20%, compact RF components, a high efficiency high-power LDMOS power amplifier with >60% power-added efficiency across a relative bandwidth of 20% at a center frequency of 435 MHz, and a digital signal generation and acquisition unit. Furthermore, we demonstrate broadband performance of our left-handed/right-handed out-of-phase power dividers. In 2008 the first data acquisition campaign will take place in Greenland.Radar Conference, 2007. EuRAD 2007. European; 11/2007