Superconducting bolometric mixers

Author

Ekstrom, H. ; Karasik, B. ; Kollberg, E. ; Yngvesson, S.K.

Author_Institution

Chalmers Univ. of Technol., Goteborg, Sweden

Volume

4

Issue

7

fYear

1994

fDate

7/1/1994 12:00:00 AM

Firstpage

253

Lastpage

255

Abstract

Mixing at 20 GHz in niobium superconducting thin-film strips in the resistive state is studied. Experiments give evidence that electron-heating is the main cause of the nonlinear phenomena. The requirements on the mode of operation and on the film parameters for small conversion loss and the possibility of conversion gain are discussed. Measurements indicate a conversion loss between 1-8 dB and a DSB mixer noise temperature between 100 and 450 K at 20 GHz. The device output noise temperature at the mixer operating point can be as low as 30-40 K. A simple theory that is based on the assumption that the small signal resistance is linearly dependent on power is presented. This type of mixer is considered very promising for use in low-noise heterodyne receivers at THz frequencies.<>

Keywords

bolometers; electron device noise; hot carriers; losses; mixers (circuits); niobium; superconducting microwave devices; superconducting thin films; 1 to 8 dB; 20 GHz; DSB mixer noise temperature; Nb; SHF; conversion gain; conversion loss; electron heating; film parameters; low-noise heterodyne receivers; nonlinear phenomena; resistive state; small signal resistance; superconducting bolometric mixers; superconducting thin-film strips; Frequency; Loss measurement; Mixers; Niobium; Noise measurement; Strips; Superconducting device noise; Superconducting films; Superconducting thin films; Temperature dependence;

fLanguage

English

Journal_Title

Microwave and Guided Wave Letters, IEEE

Publisher

ieee

ISSN

1051-8207

Type

jour

DOI

10.1109/75.298257

Filename

298257