Document Type
Patent
Publication Date
4-17-2001
Patent Number
62172107
Abstract
A radiometer calibrating system utilizes an adjustable noise source for calibrating a radiometer. The noise source includes a transistor configured as a noise equivalent circuit having a gate port, drain port and source port. A source inductance providing series feedback for the noise source has one end coupled to the source port of the noise equivalent circuit and another end connected to the ground. A bias circuit controls the amount of DC bias applied to the noise equivalent circuit. In order to match the impedances in the noise source, an output impedance matching network in connected to the drain port and an input impedance matching network is connected to the gate port of the noise equivalent circuit. The output and input impedance networks have an output port and input port, respectively. Included in the noise source is a port switch that terminates a matched load to the output port when a cold thermal radiation temperature is generated at the input port, and alternatively, the port switch terminates the matched load to the input port when the warm thermal radiation temperature is generated at the output port.
Application Number
09/319,520
Recommended Citation
Roeder, Robert S.; Smith, Matthew C.; Dunleavy, Lawrence P.; and Lardizabal, Steven M., "Variable microwave cold/warm noise source" (2001). USF Patents. 804.
https://digitalcommons.usf.edu/usf_patents/804
Assignees
Raytheon Company, University of South Florida
Filing Date
08/23/1999
Primary/U.S. Class
374/1
