Title :
Noise temperature measurement of YBCO Josephson mixers in millimeter and submillimeter waves
Author :
Shimakage, H. ; Uzawa, Y. ; Tonouchi, M. ; Wang, Z.
Author_Institution :
Lab. of Commun. Res., Kansai Adv. Res. Centre, Kobe, Japan
fDate :
6/1/1997 12:00:00 AM
Abstract :
We have investigated YBCO step-edge Josephson junctions as millimeter and submillimeter wave mixers. These mixers were integrated with an Au thin-film log-periodic antenna designed for broadband coupling of the radiation. We estimated the noise temperature of the mixer using conventional hot/cold blackbody irradiation techniques in the 100- and 300-GHz bands. We found that the Au thin-film antenna yielded about 5 dB higher coupling efficiency than that of YBCO thin film antenna, and the noise temperature decreased from 2,800 K to 1,800 K. The best receiver noise temperature, 1,200 K, was achieved in the 300-GHz band through improvement in impedance matching.
Keywords :
barium compounds; high-temperature superconductors; millimetre wave mixers; submillimetre wave mixers; superconducting device noise; superconducting device testing; superconducting junction devices; yttrium compounds; 100 GHz; 300 GHz; Au; Au thin-film log-periodic antenna; YBCO step-edge Josephson junction; YBaCuO; blackbody irradiation; broadband radiation coupling efficiency; impedance matching; millimeter wave mixer; receiver noise temperature measurement; submillimeter wave mixer; Gold; Josephson junctions; Submillimeter wave communication; Submillimeter wave technology; Substrates; Superconducting device noise; Superconducting thin films; Temperature measurement; Transistors; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
