Dielectric Resonator Technique for Surface Resistance Measurement of High Temperature Superconductors

Abstract

A shielded dielectric sapphire resonator is designed and fabricated to characterize the surface resistance of high temperature superconducting materials at 18 GHz. The resonator is loaded on a cryo-cooler that enables the measurement to be carried in the temperature range 20K to T_c. The loss contribution of the lateral surface of the copper enclosure and dielectric material is calculated by modeling the electromagnetic fields for TE_01n mode inside the cavity.

Indexing terms:

• High temperature superconductors
• Dielectric resonator
• Microwave characterization

Additional information

Notes on contributors

Mukul Misra

Mukul Misra was born at Lucknow, India, in 1969. He received BSc and MSc degrees in Physics from the Lucknow University, India, respectively in 1990 and 1993. He got the award of research fellowship from Council of Scientific and Industrial Research, India, in 1994 and joined the National Physical Laboratory, New Delhi, India, in early 1995 to work for his PhD degree.

Since 1995 he has been investigating the various aspects affecting the accuracy of microwave surface impedance measurement of high-temperature superconductors by resonant techniques. He has submitted his thesis to the University of Delhi, India, in May 1999. His current interest includes microwave characterization of high-temperature superconducting thin films and their application for microwave passive devices.

N D Kataria

N D Kataria was born in Taunggyi, Myanmar in 1948. He received the BSc (Hons), MSc and PhD in Physics from the University of Delhi, India in 1970, 1972 and 1977 respectively. Since 1977 he has been working as a scientist at National Physical Laboratory, New Delhi, India.

In 1980–82 he visited Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany under Deutscher Academischer Austauschdienst (DAAD) fellowship and worked on LTS Josephson junctions and SQUIDs. He again worked at PTB, Braunschweig from 1989–91, as contract scientist under Volkswagen-Stiftung, on growth and device fabrication of high temperature superconductor (HTS) thin film. Since 1992, he has been working on HTS thin film processing, microwave measurement and device application of HTS thin films. His current research interest is in the area HTS passive devices and high-Q dielectric resonator for frequency stable oscillator.

He is author of many scientific papers and contributed chapters in two books on microwave characterization of HTS. He is a member of Indian Cryogenic Council and recipient of 1990 AN Chatterjee Memorial award.

G P Srivastava

Ganesh Prasad Srivastava was born in 1933. He obtained doctoral degree in microwave pressure broadening studies in 1957 from University of Allahabad. He pursued future research with Nobel Laureate Prof G Herzberg in National Research Council, Ottawa, Canada from 1960 to 1962 where he made significant contribution to the field of Microwave spectroscopy. He was the first to observe rotational transition in hydrogen bounded molecules. He also worked at the University of Sheffield (UK), University of Queensland (Australia), and University Piere-et-Marie Curie (France). In India he worked at different Universities and in 1974 he became Professor of Physics and in 1980, the Head of the department and the Dean of the Faculty of Science, Delhi University.

In his research careers he has to his credit over 195 research publications in international journals spanning the fields of spectroscopy, semiconductor physics magnetism, quantum electronics and microwave superconductivity. He has contributed to many international conferences. As an academician, he played a key role in introducing electronics courses into regular science academic programs all over the country for undergraduate course on computer science. He was the first Head of the Department of Electronics Science and the first Dean of the Faculty of Interdisciplinary and Applied Sciences in University of Delhi. The microwave community has been benefited by him both as an active researcher and as an educator.

He has organised many national as well as international conferences. He is one of the persons who is instrumental in establishing the Asia Pacific Microwave Conferences. At present he is actively leading a group working in the fields of high temperature superconducting microwave electronics in Delhi University.