The HMC539ALP3/539ALP3E from Analog Devices is a RF Variable Attenuator with Frequency DC to 4 GHz, Attenuation Range 0.25 to 7.75 dB, Attenuation Step 0.25 dB, Attenuation Accuracy ±0.05 dB, Power 32 dBm (P0.1dB). Tags: Surface Mount, Digital. More details for HMC539ALP3/539ALP3E can be seen below.