What a bias tee does
A bias tee injects DC power onto an RF line, or extracts it at the other end. It lets a single coaxial cable carry both DC and RF, which is how remote LNAs, up/down-converters, and antenna electronics are powered.
How it works
- An inductor passes DC while blocking RF.
- A capacitor passes RF while blocking DC — the same principle behind DC blocks.
- Together they combine DC and RF at one port and separate them at another.
Key specs
- Frequency range — the band where insertion loss stays low.
- DC current rating — how much supply current the inductor can carry.
- Insertion loss and return loss across the band.
- Maximum DC voltage rating.
Common applications
- Powering tower-mounted amplifiers and remote radio heads.
- Biasing laser diodes and photodiodes.
- Injecting DC for antenna systems in defense platforms.
Selection advice
Choose a bias tee whose DC current rating exceeds your load with margin. Under-specified inductors saturate and degrade RF performance. Browse our bias tees with your current draw and frequency band in hand.