A broadband waveguide transfer standard for the dissemination of UK national microwave power standards
Abstract
A portable transfer standard which enables WG16 power meters to be calibrated in terms of British standards over the range 10 mW to 1 W at frequencies of 8.2, 9.0, 10.0 and 12.4 GHz is described. It consists of a commercial high directivity WG16 20 dB coupler with a thermistor mount on the side arm. The mount is contained within a temperature controlled enclosure, thermally and electrically isolated from the waveguide. The coupler feeds a fixed fraction of the microwave power in the waveguide to the thermistor where it is measured using a dc substitution technique. The sum of microwave and dc power dissipated in the thermistor is maintained constant by a self balancing bridge. The calibration factor is the ratio of the microwave power present at the ouput port to the microwave power indicated by the bridge. This ratio is found by using national standards to measure power at the output port for each frequency. Test and uncertainty analysis results are satisfactory.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- January 1982
- Bibcode:
- 1982STIN...8228498I
- Keywords:
-
- Broadband;
- Frequency Standards;
- Microwave Emission;
- Transferring;
- Waveguides;
- Calibrating;
- Metrology;
- Ohmic Dissipation;
- Portable Equipment;
- Thermistors;
- Communications and Radar