Impedance Matching Calculator

Calculate L-network component values to match two different impedances at a given frequency.

What is impedance matching?

Think of it like connecting a garden hose to a fire hydrant — if the sizes don't match, water splashes everywhere and most of it is wasted. Impedance matching ensures that electrical energy flows smoothly between components instead of bouncing back.

Why does this matter?

In a cell phone, impedance matching between the antenna (typically 50 Ω) and the radio chip ensures your signal isn't wasted as heat. An L-network is a simple two-component circuit (one inductor, one capacitor) that acts as the "adapter" to bridge the two different impedances.

Network Parameters
Enter source impedance, load impedance, and operating frequency.

The output impedance of your signal source — e.g. 50 Ω for most RF equipment, coaxial cable, and test gear.

The input impedance of the device you're driving — e.g. an antenna, amplifier, or filter. Must differ from the source impedance.

The operating frequency of your signal. The L-network components must be tuned to this specific frequency.

Transformation ratio 4.00:1 — Q factor 1.732

A higher Q factor means the network is more frequency-selective (narrower bandwidth). Lower Q = broader, more forgiving match.

Series L — Shunt C
Low-pass
Series inductor on the low-impedance side, shunt capacitor on the high-impedance side. Acts like a low-pass filter — passes low frequencies, blocks high ones.
50 ΩL⊣C200 Ω
Series Inductor (L)137.832 nH
Shunt Capacitor (C)13.783 pF

Real-world example

A cell phone antenna might be 200 Ω but the radio chip expects 50 Ω. Without matching, most of the transmit power would reflect back and heat up the chip instead of being radiated. The L-network calculated here would go between them, ensuring maximum power transfer at 100 MHz.