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9 results on '"Kettle, Danielle"'

1. Offset balancing in pseudo-correlation radiometers for CMB measurements

Author

Mennella, Aniello, Bersanelli, Marco, Seiffert, Michael, Kettle, Danielle, Roddis, Neil, Wilkinson, Althea, and Meinhold, Peter

Subjects
Astrophysics
Abstract

Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the Planck-LFI pseudo-correlation receivers which uses a tunable "gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to Planck-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to Planck-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers., Comment: 12 pages, 8 figures, accepted for publication in A&A (updated version with few editorial changes)

Published
2003
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2. A ten-beam Ka-band radiometric receiver using custom designed InP MMICs at cryogenic temperatures

Author

Kettle, Danielle and Roddis, Neil

Subjects
Microwave integrated circuits -- Design and construction, Radio astronomy -- Research, Microwave receivers -- Design and construction, Radiation -- Measurement, Radiation -- Methods, Business, Computers, Electronics, Electronics and electrical industries
Abstract

Large ground-based radio telescopes are increasingly being equipped with multibeam feed systems to enable simultaneous observation of a larger part of the sky. The aim of the One Centimetre Receiver Array-f project, part of the European Commission funded FARADAY Programme, was to develop a high-quality science instrument to survey the sky at 1-cm wavelength, while developing technologies that would be applicable to future development of systems with 100 beams or more. A complete ten-beam Ka-band radiometer system is described, together with measured results at cryogenic temperatures. Performance compares well with that obtained with similar (non monolithic microwave integrated circuit) instruments produced for the Wilkinson Microwave Anisotropy Probe and Planck satellites. Index Terms--Cryogenic, InP, Ka-band, monolithic microwave integrated circuit (MMIC), radio astronomy, radiometry.

Published
2007

3. Very low-noise differential radiometer at 30 GHz for the PLANCK LFI

Author

Aja, Beatriz, Artal, Eduardo, de la Fuente, Luisa, Pascual, Juan Pablo, Mediavilla, Angel, Roddis, Neil, Kettle, Danielle, Winder, W. Frank, Cara, Lluis Pradell i, and de Paco, Pedro

Subjects
Microwave devices -- Research, Radiometers -- Research, Business, Computers, Electronics, Electronics and electrical industries, European Space Agency
Abstract

The PLANCK mission of the European Space Agency is devoted to produce sky maps of the cosmic microwave background radiation. The low-frequency instrument is a wide-band cryogenic microwave radiometer array operating at 30, 44, and 70 GHz. The design, test techniques, and performance of the complete differential radiometer at 30 GHz are presented. This elegant breadboard 30-GHz radiometer is composed of a front-end module (FEM) assembled at the Jodrell Bank Observatory, Cheshire, U.K., and a back-end module assembled at the Universidad de Cantabria, Cantabria, Spain, and Telecomunicacio, Universitat Politecnica de Catalunya, Barcelona, Spain. The system noise temperature was excellent, mainly due to the very low noise performance of the FEM amplifiers, which achieved an average noise temperature of 9.4 K. Index Terms--Cosmic microwave background (CMB), cryogenic, low-noise amplifier (LNA), microwave radiometer, PLANCK low-frequency instrument (LFI).

Published
2005

5. Very Low-Noise Differential Radiometer at 30 GHz for the PLANCK LFI

Author

Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RF&MW - Grup de Recerca de sistemes, dispositius i materials de RF i microones, Aja, Beatriz, Artal Latorre, Eduardo, Fuente, Luisa de la, Pascual, Juan Pablo, Mediavilla, Asier, Roddis, Neil, Kettle, Danielle, Winder, W. Frank, Pradell i Cara, Lluís, Paco Sánchez, Pedro Antonio de, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. RF&MW - Grup de Recerca de sistemes, dispositius i materials de RF i microones, Aja, Beatriz, Artal Latorre, Eduardo, Fuente, Luisa de la, Pascual, Juan Pablo, Mediavilla, Asier, Roddis, Neil, Kettle, Danielle, Winder, W. Frank, Pradell i Cara, Lluís, and Paco Sánchez, Pedro Antonio de

Abstract

The PLANCK mission of the European Space Agency is devoted to produce sky maps of the cosmic microwave background radiation. The low-frequency instrument is a wide-band cryogenic microwave radiometer array operating at 30, 44, and 70 GHz. The design, test techniques, and performance of the complete differential radiometer at 30 GHz are presented. This elegant breadboard 30-GHz radiometer is composed of a front-end module (FEM) assembled at the Jodrell Bank Observatory, Cheshire, U.K., and a back-end module assembled at the Universidad de Cantabria, Cantabria, Spain, and Telecomunicacio/spl acute/, Universitat Polite/spl acute/cnica de Catalunya, Barcelona, Spain. The system noise temperature was excellent, mainly due to the very low noise performance of the FEM amplifiers, which achieved an average noise temperature of 9.4 K., Peer Reviewed

Published
2005

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