Pasternack bias tees, also known as the bias Ts, are passive coaxial components that are mainly used in applications where DC current injection is required or when voltages need to be introduced to a circuit. The bias tees are able to inject DC current into an RF circuit without interrupting or affecting the RF signal as it passes through the main transmission path.
These are ideal for applications requiring DC power to power amplifiers on antennae and similar RF circuits. The unit gets its name from the design of the three ports, which are generally in a T shape, and Pasternack bias tees possess a maximum voltage rating of between 24 and 100V. There are two different bias connector designs available, including SMA female and solder pin.