Wr-22 Noise-Temperature Measurement Service Opened - Brief Article - Statistical Data Included

Journal of Research of the National Institute of Standards and Technology, Nov, 2000

NIST has completed construction and verification of a new radiometer system for measuring the noise temperature of sources with WR-22 waveguide flanges. The system offers continuous frequency coverage of the 40 GHz to 50 GHz portion of the WR-22 band. The lower portion of the band (33 GHz to 40 GHz) can be measured through adapters on the existing WR-28 system.

The new WR-22 system is a total-power radiometer, with an internal six-port reflectometer to measure relevant reflection coefficients. Its design is similar to that of existing NIST waveguide systems. It is capable of measuring sources with noise temperatures from about 50 K to 15 000 K, with typical relative expanded uncertainties (k = 2) expected to be about 1.6 % or 1.7 % for sources with noise temperatures from 1000 K to about 12 000 K and reflection coefficients of less than about 0.1. With this new WR-22 measurement service and the recent upgrade of its WR-90 service, NIST now offers noise-temperature measurement services for waveguide noise sour ces for any frequency from 8.2 GHz to 65 GHz, with the exception of the 26.01 GHz to 26.5 GHz range of the WR-42 band.