The 40/20S1G18 from AR RF/Microwave Instrumentation is a RF Amplifier with Frequency 700 MHz to 4.2 GHz, Gain 46 dB, Gain Flatness ±2 dB, Noise Figure 10 dB, Output Power 45.44 to 46.43 dBm. Tags: Power Amplifier. More details for 40/20S1G18 can be seen below.