The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
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Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Faculty of Electronics, Communications and Automation for public examination and debate in Auditorium S4 at Helsinki University of Technology (Espoo, Finland) on the 13th of February, 2009, at 12 noon.
Overview in PDF format (ISBN 978-951-22-9748-1) [10788 KB]
Dissertation is also available in print (ISBN 978-951-22-9747-4)
The purpose of this thesis was to develop very low noise cryogenic receivers and related high accuracy measurement setups to validate the operation of the receivers. Different types of cryogenic noise measurement setups were developed and compared. The noise measurement accuracy was improved for cryogenic temperatures at millimeter wave frequencies. A demonstrator was built for the continuous comparator receiver topology at millimeter waves. Measurement equipment were constructed to validate the receiver operation. Finally, an integrated 70 GHz continuous comparator receiver was built and suitable measurement tools were developed to ensure proper spacecraft operation.
Individual cryogenic amplifiers showed the best noise and gain results at the time of measurement. The noise temperature of the 20 K physical temperature split block mounted amplifiers was −30 K, very close to its physical limits. The demonstrator receiver measurements expanded the knowledge of operation of continuous comparator millimeter wave receivers. A noise temperature of 40 K was measured for the demonstrator receiver, providing 1⁄f-knee frequencies lower than 10 mHz. The receiver topology was verified at 70 GHz with high stability at cryogenic temperatures. The integrated receiver was measured to have noise temperature of 30 K and a 1⁄f-knee frequency lower than 50 mHz. The integrated receiver was developed for the Elegant Bread Board (EBB) receiver in ESA's Planck Project. The required measurement equipment and facilities were built for spacecraft payload simulation. A large cryogenic chamber and cooling system were also designed and constructed for testing.
This thesis consists of an overview and of the following 7 publications:
Keywords: noise measurement, measurement electronics, cryogenic, millimeter wave, receiver
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© 2009 Helsinki University of Technology