Broadband Impedance Matching Synthesizer
Synthesize L, Pi, T, or ladder matching networks for broadband impedance transformation. Enter source/load impedances across a frequency band and get optimized component values with simulated S-parameters.
How It Works
Impedance matching maximises power transfer between a source and load by transforming one impedance to the conjugate of the other. A single L-network (one series + one shunt reactive element) is the simplest topology, but it provides limited bandwidth because the Q factor of the match is fixed by the impedance ratio.
For broader bandwidth, Pi and T networks add a third element, giving a degree of freedom to trade insertion loss against bandwidth. Multi-section ladder networks (Chebyshev or maximally-flat tapers) extend this further, achieving decade bandwidths at the cost of more components and higher loss.
This tool uses analytic synthesis for L/Pi/T topologies and numerical optimisation (least-squares on |S11|) for ladder networks, then simulates the complete S-parameter response across your specified frequency band so you can verify return loss and insertion loss before building.
Related Calculators
FAQ
What impedance ratio can an L-network handle?+
An L-network can match any two real impedances, but the resulting Q — and therefore bandwidth — is determined by the ratio. Large ratios (>10:1) yield high Q, meaning very narrow bandwidth. Use Pi, T, or ladder topologies for wideband matching at high ratios.
Why does my match degrade at higher frequencies?+
Parasitic effects (component self-resonance, PCB trace inductance) shift the actual impedance away from ideal values. At frequencies above a few GHz, consider using distributed (transmission-line) matching instead of lumped elements.
How do I interpret the S-parameter results?+
S11 (return loss) should be below -10 dB across your band for a good match. S21 (insertion loss) shows how much power the network absorbs — lower is better. The Smith chart overlay shows the impedance trajectory across frequency.
What is the difference between Pi and T networks?+
A Pi network has two shunt elements and one series element; a T network has two series elements and one shunt element. Both provide an extra degree of freedom over an L-network. Pi networks are preferred when the source impedance is high; T networks when it is low.