Engineering NotesPOWER RF AMPLIFIERS TECHNICAL REFERENCE MATERIALGainNormaly expressed in decibels, dB Power Gain (dB) = 10 Log _{10} (RF Output Power / RF Input Power) Gain is defined as the ratio of the output power to the input power in dB. Assume that the input power is 10 mW (+10 dBm) and the output power is 1 W (1000 mW, +30 dBm). The ratio will be 1000/10 = 100, and the gain will be 10 * log 100 = 20 dB. It is much easier to calculate gain by converting the power to dBm first, so the gain of the above amplifier will be 3010 = 20 dB. A simple reduction will reveal the gain. In tradition, all power is read in dBm and the gain is in dB. Example:

EN HomeUsing CCDF as a Method of Measuring P1dB and P3dB RF Glossary of Terms Watts to dBm and dBm to Watts Conversion Calculator RF Amplifiers Gain Passband Frequency Range Gain Flatness RF Power Pulsed Power Peak Envelope Power Harmonics & Spurious Intercept Point Intermodulation Distortion Multitone IMD Monograph Noise Figure & Level Modulation Types VSWR & Return Loss (Impedance) Load VSWR & Protection Leveling Loops, Input Overdrive Protection Graceful Degradation Protection Circuits DC Input Power & Efficiency Cooling Methods Class of RF Amplifiers Class A Operation Class AB Operation Class C operation 