General 650 GHz Tuning
Initially, tune the receiver for maximum total power in the
Check the magnetic field. Turn on the magnetic field, and either look at the
LO must be on the receiver to set the magnetic field.
Minimized the magnetic field (current) since it suppresses the superconducting energy gap, which results in degraded receiver performance.
650 GHz Receiver Tuning in Detail
There are three Multipliers for this Receiver:
660-720 GHz, RPG Physics, X6, Self biased (1994 model, 4 tuners, refer to data sheet for settings)
600-660 GHz, RPG Physics, X5, Manual bias (1991 model, 4 tuners, refer to data sheet for settings.
Do not exceed 4 mA on Doubler
Do not exceed 2 mA on Tripler
Rx Tuning Procedure:
Refer to the
Receiver Tuning Cookbook.
Bias the junction to
Set the Magnetic field Current to about 20-35 mA (+ or -).
Optimum junction current is typically about 9-11uA.
From now on the tuning process is iterative. That is, optimize the SIS current by adusting the:
When finished tuning, make a final check of the
Make sure the
Finally it is best to put the SIS bias voltage on a flat spot of the P/V curve (dP/dV=0). This is critical because in this way the
Please do remember to
Last but not least, do perform standard Y-factor measurements to make sure that the receiver properly works
Rx Tuning Menu
I/V sweep Menu
Web Page created and last updated on March 5, 2001, by:
Jacob W. Kooi