Constructing 100 mW FeedthroughPower Standard

Constructing 100 mW FeedthroughPower Standard

Commercially available power meters and sensors have measurement ranges up to several watts. Accurate measurements with these devices require periodic calibration with traceable standards.

Conventional calibrations typically take place in the 1mW to 10mW range. This range can be extended downwards for highly sensitive diode sensors by means of a calibrated attenuator.

Raising the calibration level above 10mW, to calibrate higher power sensors well above their noise floor, has been more of a problem. For example, one calibration technique separates the front end attenuator from the sensor, and calibrates the two devices independently. However, this creates measurement uncertainty when the data is combined.

This app note describes a basic technique for generating an accurate 100 mW power source. The technique extends the advantages of a lower power calibration to higher power units.