Balun & RF Transformer Calculator
Calculate balun and RF transformer turns ratio, impedance transformation ratio, and insertion loss for balanced/unbalanced feed line matching.
Formula
How It Works
A balun (balanced-unbalanced) transformer is a critical RF component that transforms impedance between balanced and unbalanced transmission lines or circuits. The primary function is to match impedances and transition between different circuit configurations, typically converting between single-ended and differential signaling. The key parameter is the turns ratio, which determines the impedance transformation and is calculated by the square root of load impedance divided by source impedance.
Worked Example
Problem: Design a 4:1 impedance transformer balun with a source impedance of 50Ω and target load impedance of 200Ω Solution: 1. Verify turns ratio: N = √(200/50) = √4 = 2 2. Confirm impedance transformation: 50Ω * (2)² = 200Ω 3. Select appropriate core material with suitable permeability for frequency range 4. Wind transformer with calculated turns ratio 5. Verify matching and minimal insertion loss
Practical Tips
- ✓Choose low-loss ferrite cores matched to operating frequency
- ✓Use precise winding techniques to minimize stray capacitance
- ✓Consider skin effect and proximity effect at high frequencies
- ✓Validate transformer performance with network analyzer
Common Mistakes
- ✗Neglecting core material frequency limitations
- ✗Incorrect winding technique causing increased insertion loss
- ✗Overlooking parasitic capacitance at high frequencies
- ✗Using inappropriate core material for specific frequency range
Frequently Asked Questions
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