Question

 

If every RF power measurement has a calibration uncertainty of 0.15 dB, discuss the relative accuracy of RF path calibration by separately calibrating individual components versus doing a single end-to-end calibration

Answer 1

 

Power meters works that do not employ electronic calibration come with a graph tabular data showing the calibration factors (C.F) and correction factors by frequency used will take the relative calibration factor (C.F) in percent and use if the calibration power meter at the calibration reference frequency..

The nosare usually a percent of full scale response and can vary from 80% or so to 100%. Let's say your sensor reference. And C.F of the frequency st which your s/g of interest occupies is 95%. If you , like many uses , carefully perform a calibration and then plug the sensor to the s/g and make your measurement if is still in error by at 5% or about 0.2 dB.

When you are using power sensor with a correction table by frequency you must enter the % correction as shown the sensor fir the frequency being measurement.if you are useing power sensor with electronic calibration data you must still enter a frequency to allow the meter to make the correction..

The main advantage of electronic calibration sensors is you don't have to interpolate the calibration % by frequency from data table can graph. C.f uncertinity increases with frequency from about 1% to 3% depending on frequency range . For frequency not enumerated or b/w data provided, you are using the wrong sensor...