The HEM387D from Sainty-Tech Communications Limited is a RF Amplifier with Frequency 100 to 700 MHz, Gain 21 to 22 dB, Gain Flatness ±0.5 dB, Noise Figure 3.8 dB, Output Power 20 to 21 dBm. Tags: Power Amplifier. More details for HEM387D can be seen below.