Conversion gain and noise in a Josephson mixer. Technical report

Technical Report · Mon Oct 01 04:00:00 EDT 1973

OSTI ID:7324354

Taur, Y; Claassen, J H; Richards, P L

Fundamental mixing at 36 GHz in non-hysteretic Nb point contacts has been observed with overall conversion efficiencies in the range 0.33 < or = eta < or = 4 and mixer noise temperatures in the neighborhood of ( Taub M) approximately 200K. The observed conversion efficiencies are in good agreement with the Resistively Shunted model. The observed noise can be accounted for by assuming that the Johnson noise in the shunt resistor is the only source of noise driving the junction. Somewhat larger noise is seen from resonantly coupled mixers than is seen when the mixer is driven from an rf current source. Fundamental mixing in hysteretic junctions is limited to a narrow if bandwidth and gives much larger conversion gain but also larger noise. Parametric amplification at the if frequency is seen in hysteretic junctions. Fourth order harmonic mixing with omega sub (LO)/2 pi at 9GHz has been achieved with performance almost comparable to fundamental mixing. Cavity mode mixing appears less promising.

• Research Organization: California Univ., Berkeley (USA). Dept. of Physics
• OSTI ID: 7324354
• Report Number(s): AD-769222/1
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment &amp; Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
EFFICIENCY
ELECTRONIC EQUIPMENT
GAIN
HYSTERESIS
JOSEPHSON JUNCTIONS
MULTIPLEXERS
NOISE
PARAMETRIC AMPLIFIERS
SUPERCONDUCTING JUNCTIONS