Cryogenic parametric amplifier control apparatus
A cryogenic parametric amplifier control apparatus is disclosed. Methods of implementation and devices incorporated within the whole of the apparatus are disclosed. Methods of reducing the number of signal lines necessary to control a parametric amplifier are disclosed. Schema allowing for control of multiple parametric amplifiers with a single apparatus are disclosed.
1 . A method of multiplexing outputs of two or more cryogenic amplifiers housed within a cryogenic system, the method comprising:
disposing a power divider/combiner onto a cooling stage, the cooling stage-operating at a lower temperature than room temperature;
coupling respective ones of the two or more outputs to corresponding input ports of the power divider/combiner, to thereby reduce a number of connections through at least one stage of the cryogenic system;
combining a test signal with one or more pump signals fed to the cryogenic amplifiers;
monitoring the test signal at one or more outputs of the cryogenic amplifiers; and
wherein the monitoring further comprises detecting the test signal via a microwave detector or homodyne receiver, or by selectively enabling a DC bias to one or more of the cryogenic amplifiers.
2 . A method of multiplexing outputs of two or more cryogenic amplifiers housed within a cryogenic system, the method comprising:
disposing a power divider/combiner onto a cooling stage, the cooling stage-operating at a lower temperature than room temperature;
coupling respective ones of the two or more outputs to corresponding input ports of the power divider/combiner, to thereby reduce a number of connections through at least one stage of the cryogenic system;
combining, with the power divider/combiner, output signals from two or more of the cryogenic amplifiers to generate a single combined output signal; and
routing the combined output signal away from the cooling stage along a transmission path toward room-temperature electronics, thereby decreasing a number of signal lines that traverse the cooling stage.
3 . The method of claim 2 , wherein the cooling stage is a 50 K stage, a 4 K stage, a still stage, a cold-plate stage or a mixing-chamber stage of a cryogenic refrigerator.
4 . The method of claim 2 , further comprising filtering the combined output signal with a cryogenic low-pass or band-pass filter located on the cooling stage with the power divider/combiner.
5 . The method of claim 2 , further comprising supplying a DC bias to each of the cryogenic amplifiers through bias lines that are thermally anchored at multiple temperature stages of the cryogenic system.
6 . A method of multiplexing outputs of two or more cryogenic amplifiers housed within a cryogenic system, the method comprising:
disposing a power divider/combiner onto a cooling stage, the cooling stage-operating at a lower temperature than room temperature;
coupling respective ones of the two or more outputs to corresponding input ports of the power divider/combiner, to thereby reduce a number of connections through at least one stage of the cryogenic system; and
disposing a cryogenic isolator or circulator between each amplifier output and the corresponding input port of the power divider/combiner.
7 . The method of claim 6 , wherein a combined output signal provided by the power divider/combiner is fed through a single coaxial cable that exits the cryogenic system.
8 . The method of claim 6 , wherein the cooling stage is a 50 K stage, a 4 K stage, a still stage, a cold-plate stage or a mixing-chamber stage of a cryogenic refrigerator.
9 . The method of claim 6 , further comprising filtering a combined output signal provided by the power divider/combiner with a cryogenic low-pass or band-pass filter located on the cooling stage with the power divider/combiner.
10 . The method of claim 6 , further comprising supplying a DC bias to each of the cryogenic amplifiers through bias lines that are thermally anchored at multiple temperature stages of the cryogenic system.
11 . A method of multiplexing outputs of two or more cryogenic amplifiers housed within a cryogenic system, the method comprising:
disposing a power divider/combiner onto a cooling stage, the cooling stage operating at a lower temperature than room temperature;
coupling respective ones of the two or more outputs to corresponding input ports of the power divider/combiner, to thereby reduce a number of connections through at least one stage of the cryogenic system;
providing a test signal tone into at least one input port of the power divider/combiner; and
monitoring the test signal at the combined output to characterize the cryogenic system.