Waveguide Power Transfer Standards - Multi-State Reflectometers
Simply use the links to learn more about each product area.
Multi-State Reflectometers (MSRs) are used by Primary and Secondary Standards laboratories for calibrating microwave power sesnors for efficiency (or calibration factor) and impedance (VRC).
Application
Primary microwave power standards such as micro-calorimeters are generally slow to operate and are designed to calibrate specific types of power sensor. Typically a calibration or standards laboratory will hold several power standards which are either calibrated locally in a microcalorimeter or against other power standards supplied by a higher echelon laboratory. A multi-state reflectometer is commonly used to rapidly and efficiently calibrate other sensors against these local standards. This type of instrument has the advantage of being able to simultaneously measure both the efficiency of the device as well as the input Voltage Reflection Coefficient. As highly linear thermistor detectors are used in the MSR it can also be used to check the linearity of other sensors.
Frequency Coverage
NPL operates waveguide reflectometers in multiple waveguide sizes from 8.2 to 110 GHz, Being built to order they can, in principle, be built to operate over any standard rectangular waveguide band.
Dynamic range
Our systems operate over a typical power range of 0.1 to 10 mW, matching the commonly range of power level required by standards laboratories.
Supported devices
The software and hardware will support the majority of commercial power sensors and meters employed in standards, calibration and testing laboratories. Our systems are regularly being developed to support the latest generation of power sensors, many of which now include internal electronic frequency correction.
Associated Equipment
NPL is able to deliver complete power transfer facilities which would includes a reflectometer system, calibrated power standards, impedance calibration kits and a microwave source. Measurement and analysis software together with a control PC can also be supplied. Documentation including operating procedures are available and training in the system use can be delivered, either at NPL or at the user’s laboratory.
Uncertainties
The reflectometers, being developed from our own standards, potentially offer the user comparable measurement uncertainties to that available from NPL’s measurement service. Ultimately the measurement uncertainty available from a reflectometer will depend on the quality of the device being measured and the uncertainty of the local calibration standards. Our capabilities have been verified and accredited by the United Kingdom Accreditation Service (UKAS) and our capability can be found on their website and also on the BIPM Calibration and Measurement Capability database.