Measurement and Control of RF Power (Part I):IntroductionFig. 1. shows a typical modern communications signal chain. The signal to be transmittedis generated at baseband by a digital-to-analog converter (DAC.) This signal is thenmixed up to an intermediate frequency (IF) where it is filtered before being mixed up tothe final radio frequency (RF.) On the receive side the inverse transformation takes place.The received signal is amplified, mixed down to IF and filtered before being mixed downto baseband where it is digitized.