Maintenance-Free Cryogenic Noise Standard for Continuous Antenna Operation Independent of Elevation Angle

Current stringent demands for high-accuracy measurements in low-noise technology have created a need for cryogenic noise standards, usually of liquid refrigerant type. However, implementation of this type of standard in large earth stations imposes problems where measurements must be performed for arbitrary antenna inclination angle and during active communication phase between a satellite and an earth station. A cryogenic noise standard utilizing helium gas refrigerant has been developed, installed, and made operative for continuous operation with minimal maintenance service without the aforementioned constraints.