Example Data Table
These examples illustrate typical impedance transforms at common RF frequencies.
| Example | Frequency | Rs (Ω) | Rl (Ω) | Qmin | Low-pass Series L | Low-pass Shunt C |
|---|---|---|---|---|---|---|
| 50→200 Ω | 100 MHz | 50 | 200 | 1.732 | ~138 nH | ~13.8 pF |
| 75→50 Ω | 10 MHz | 75 | 50 | 0.707 | ~0.56 µH | ~450 pF |
| 25→50 Ω | 1 MHz | 25 | 50 | 1.000 | ~3.98 µH | ~3.18 nF |
Note: Example values are rounded and assume purely resistive impedances.
Formula Used
The L-match transforms between two resistances using a loaded quality factor: Q = √(Rhigh/Rlow − 1). Reactance magnitudes follow: Xseries = Q·R (series side), and Xshunt = R/Q (shunt side), using either the low-resistance or high-resistance side depending on the chosen solution.
Convert reactance to components at frequency f: L = X/(2πf) and C = 1/(2πfX). Low-pass uses a series inductor and shunt capacitor; high-pass swaps them.
How to Use This Calculator
- Enter frequency and select its unit.
- Provide source resistance (Rs) and load resistance (Rl).
- If your load has reactance, enter Xl and enable pre-tune.
- Choose low-pass, high-pass, or show both for comparison.
- Press Calculate to view results above the form.
- Use CSV/PDF to export your saved calculation history.
Saved History Preview
The last few rows are kept for quick checking and exports.
No saved rows yet. Run a calculation to populate history.