National Physical Laboratory

New technique for calibration of RF devices

A new technique proves successful in more accurately assessing the performance of an innovative product designed and manufactured in the UK.

NPL system demonstrating AM calibration of a 9640A RF source
NPL system demonstrating AM calibration of a 9640A
RF source

The Challenge

Calibration of radio frequency (RF) devices has typically required several different pieces of equipment such as a signal sources, power meters and reference sensors. Fluke Precision Measurement, an international company that specialises in electrical calibration equipment, spotted a gap in the market for a single device to provide accurate RF calibration signals without requiring additional equipment. The research, design, development and manufacture were carried out at Fluke's UK arm in Norwich and the result is the Fluke 9640A RF Reference Source.

Traceable calibrations are vital in order to demonstrate and give confidence in the instrument's technical capabilities. However, in the case of amplitude modulation (AM), an important feature of the 9640A, Fluke had a measurement problem. The usual methods of measuring AM have too high an uncertainty to be able to verify that the instrument is as good as Fluke believe it to be. A technique to accurately and traceably demonstrate the AM performance of this instrument would improve its value to end users, and increase the potential sales figures.

The Solution

NPL's Matthew Harper spent two weeks on secondment to Fluke investigating the application of a new technique, in-phase quadrature (IQ), to achieve AM calibration. He succeeded in establishing that this technique had potential to provide traceability at the low uncertainty levels that Fluke required. Fluke were left with a system and software that allowed them to further refine the measurements through collaboration with NPL.

The Impact

"Working together with a member of NPL staff on-site was a significant factor in understanding and demonstrating the potential for this novel measurement technique in our particular application. The two-week secondment has saved Fluke between three to six months of internal engineering development work."
Paul Bunyan, Head of Metrology, Fluke Precision Measurement Ltd

Find out more about NPL's research in Wireless Communications

Do you have a measurement challenge that you'd like NPL's help with? If so, why not apply for NPL's Technology Innovation Fund ?

Last Updated: 29 Jul 2013
Created: 7 Oct 2010


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