Accurate Gain/Phase Measurement At Radio Frequencies Up To 2.5 GHz

By John Cowles and Barrie Gilbert

Electronic circuits fall into two broad categories—those that process and transform signals and those that measure signals. Their functions are often combined, as in the IF section of a receiver— which processes the signal (by amplification and demodulation), and also delivers an indication of received signal-strength (the RSSI function), a slowly-varying voltage that may be displayed and/or used for automatic control of variables such as gain and frequency (AGC and AFC). For more information on this topic, download the full article.