The APT4-18004000-4008-B18 from AmpliTech, Inc. is a RF Amplifier with Frequency 18 to 40 GHz, Gain 37 to 45 dB, Gain Flatness ±3 dB, Noise Figure 3 to 3.5 dB, Output Power 8 to 12 dBm. Tags: Power Amplifier. More details for APT4-18004000-4008-B18 can be seen below.