What a balun does
A balun converts a balanced (differential) signal to an unbalanced (single-ended) one, or vice versa. The name is a contraction of balanced to unbalanced.
Why it matters
- Many antennas and mixers are differential, while most test gear and transceivers are single-ended.
- A balun also provides impedance transformation, such as 50 ohm to 100 ohm or 200 ohm.
Key specifications
- Frequency range and insertion loss.
- Phase and amplitude balance between the two balanced ports.
- Impedance ratio, such as 1:1, 1:2, or 1:4.
- Power handling for transmit applications.
Common applications
- Feeding dipole antennas.
- Driving double-balanced mixers.
- Interfacing differential ADC and DAC front-ends.
- A 180-degree hybrid coupler can perform the same balanced-to-unbalanced function in wideband systems.
Selection tip
Prioritize amplitude and phase balance when your application is sensitive to common-mode rejection. Browse our RF baluns.