The HE641D from Sainty-Tech Communications Limited is a RF Amplifier with Frequency 500 to 2500 MHz, Gain 24 to 25 dB, Gain Flatness ±1.0 dB, Noise Figure 4.5 dB, Output Power 24.8 to 25.3 dBm. Tags: Power Amplifier. More details for HE641D can be seen below.