The ZFBT-4R2GW from Mini Circuits is a bias tee that operates from 0.1 MHz to 4.2 GHz. It has an insertion loss of 0.6 dB, isolation of 40 dB and a VSWR of 1.13:1. It can be used for biasing amplifiers and active antennas, DC blocking and test accessory applications. The Bias Tee has a 0.5 A current rating and 30 V DC voltage rating.