Maury thermal terminations are low-mismatch, heated loads in a precisely controlled thermal environment which provide an accurately known noise power. Used with ambient and/or cryogenic terminations and a noise figure meter, these terminations provide the hot termination temperature needed for highly accurate noise figure or effective input noise temperature measurements. Because of the accuracy of the noise output, thermal terminations are often used as a noise standard for calibration of solid state noise generator.
The accuracy achieved by these terminations is possible because they utilize the proven concept of thermal (Johnson) noise operating in a precision thermal environment provided by the MT151C temperature controller. (The MT151C is a highly stable, proportional temperature controller that is accurately calibrated against NIST-traceable temperature measuring equipment.) This is the same concept used in several national standards laboratories and NIST at the higher microwave frequencies.
The termination and the controller are matched during calibration; therefore, the two instruments must be purchased as a unit. In addition, a line voltage option must be specified. Each unit is provided with a calibration report which includes VSWR and available output noise temperature at specific frequencies.
Maury offers the MT7250 series Noise Calibration Swept Data Module as a software tool that allows users to work with other non-standard data points in addition to, or in place of, the factory standards. Maury also offers as are accessories such as an instrument case and calibrated adapters to other coaxial series or waveguide.
Application Notes and Data Sheets
Technical Data - Model MT7108B - 7mm Coaxial Thermal Noise Termination
Technical Data - Model MT7005A - Waveguide Thermal Noise Termination (3.7 - 4.2 GHz, WR229)
Application Note - Applications of the Maury Noise Calibration Systems; Accuracy & Convenience in Noise Measurement