Baluns

What is an RF balun?

An RF balun is a passive component that converts between balanced and unbalanced signals. Depending on the selected device, a balun can also provide impedance transformation and filtering within the RF signal path. Johanson Technology offers integrated surface-mount RF baluns designed for wireless front-end applications

What does “balun” mean?

The term balun is derived from “balanced-to-unbalanced.” A balun converts a balanced RF signal, which uses two conductors with opposing signal phases, to an unbalanced signal referenced to ground, or performs the conversion in the opposite direction.

Why is a balun used in an RF front end?

A balun is commonly used when a balanced RF port must connect to an unbalanced circuit or transmission line. Johanson’s integrated RF baluns can combine balanced-to-unbalanced conversion, impedance matching, and filtering in one compact component, helping simplify the RF front-end design and reduce PCB area

How do I select the correct RF balun?

Select an RF balun by reviewing the application’s operating frequency, balanced impedance, unbalanced impedance, impedance transformation ratio, insertion loss, phase difference, package size, and chipset requirements. The selected balun should be evaluated under the actual PCB layout and RF operating conditions. Johanson’s online part table provides frequency, balanced impedance, insertion-loss, phase-difference, lifecycle, and chipset-matching information where available

What wireless applications use RF baluns?

Johanson’s integrated RF baluns are intended for wireless front-end designs, including applications using Bluetooth, Wi-Fi, Zigbee, LoRa, and other wireless protocols. The available product range covers multiple operating-frequency bands and impedance configuration

How do integrated RF baluns reduce PCB space?

An integrated balun combines functions that might otherwise require multiple discrete components, including balanced-to-unbalanced conversion, impedance matching, and, in selected designs, filtering. Integrating these functions into a compact surface-mount package can reduce component count and the PCB area required for the RF front end

Can an integrated balun replace a discrete RF matching network?

An integrated balun may replace multiple discrete components when the device provides the required balanced-to-unbalanced conversion, impedance transformation, and filtering for the RF design. Suitability depends on the chipset impedance, operating frequency, insertion-loss requirement, phase balance, PCB layout, and other system conditions. The balun datasheet and S-parameters should be reviewed before replacing a discrete network.

Are S-parameter files available for Johanson RF baluns?

Yes. The Johanson RF balun page states that S-parameter files are available through the Info link next to each applicable part number. Engineers can use these files when evaluating frequency response and integrating the component into an RF simulation