Bias Tee: Delivering DC Power Without Disrupting RF Signals

A bias tee combines DC power and RF signals on the same transmission line, letting a single cable carry both without interference between them.

What Is a Bias Tee?

A bias tee is a three-port RF component that injects a DC bias voltage into an RF signal path, or separates the two when needed. It allows a device like an amplifier or laser diode to receive power directly through the same line carrying its RF signal.

Build and Design

The Bias Tee range from Flexi RF Inc covers frequency ranges starting from 30 KHz up to 18 GHz, with SMA interfaces and low insertion loss. These units maintain high isolation between the DC and RF paths, which helps keep power delivery stable while protecting sensitive RF equipment from unwanted interference.

Where It's Used

Bias tees are commonly used to power active components like amplifiers, laser diodes, and optical modulators in lab testing and communication systems. They remove the need for a separate power line, which simplifies wiring in compact test setups.

Pairing With a 1.85mm Load

In a full RF test setup, unused or terminated ports still need proper handling once a bias tee is in place. A 1.85mm load is a practical addition here, rated up to 67 GHz with a passivated stainless steel body and low VSWR. Terminating an unused port correctly helps prevent reflected power from disrupting the rest of the signal chain, especially in setups where a bias tee is actively feeding power into an active component.

Why Choose Flexi RF Inc

Flexi RF Inc manufactures a wide range of RF and microwave components, including bias tees, loads, connectors, and cable assemblies, with over 10,000 products across 10+ product lines. All orders ship the same day, with support available from experienced RF engineers who can help confirm the right combination of components for a specific test setup. Visit Flexi RF Inc to explore the full product range.