1 channel rf SQUID Controller

The JSQ SQUID Electronics Controller is the user front end for a JSQ SQUID Electronics Preamplifier. Together it is used to generate the pumping radio frequency for SQUID operation, with the required adjustments of rf frequency and amplitude for working point adjustment. Furthermore, the electronics serves as preamplifier and demodulator of the rf response of the SQUID. The SQUID is kept at a well-defined flux state (working point). This operating principle ensures a linear transfer function. It allows a dynamic range from a few 10-5 to about 103 magnetic flux quanta with excellent linearity.


Schematic of the JSQ Electronics. The parameters denoted in blue are user-adjustable.


Parameters of the JSQ 1 Ch rf SQUID Electronics:
RF power outputadjustable from –72 dBm to –118 dBm
Frequencyadjustable from 450 MHz to 900 MHz
Total amplification~ 100 dB
signal output amplitude±10 V
modulation output amplitudeadjustable from 0 – 2 Vpp


Electrical Connections 1 Ch Controller

Sketch of the electrical connections for SQUID operation. The components sketched in yellow belong to the JSQ SQUID Electronics Controller. For SQUID readout, the controller needs to be connected to the preamplifier (blue).


Front and back side of the JSQ 1 Ch rf SQUID Electronics Controller. The left photo
shows the electrical connectors to power supply, computer and oscilloscope, the
right one the connectors to the JSQ Electronics Preamplifier.