01RF engineering guide
RF impedance matching from load to verified response
Learn a repeatable RF impedance matching workflow using complex impedance, S11, return loss, Smith charts, reactive networks, and bandwidth checks.
RF engineering library
RF design and circuit simulation guides
Practical material about impedance matching, S-parameters, Smith charts, frequency response, and repeatable RF tuning workflows.
02RF engineering guide
S11 and S21 explained for RF filter simulation
Learn what S11 and S21 mean, how return and insertion loss relate to them, and how to read RF filter plots for reflection and transmission.
03RF engineering guide
Smith chart impedance matching, step by step
Learn how to normalize impedance, read reflection coefficient, add series and shunt elements, and verify a Smith chart matching network across frequency.
04RF engineering guide
SPICE AC analysis and Bode plots for circuit design
Set up a SPICE AC sweep, choose the small-signal source, plot gain and phase, place Bode markers, and avoid confusing AC analysis with transient simulation.
05Application workflow
Tune an RF matching network in Tersa EDA
Follow a practical Tersa EDA workflow: prepare RF ports, run an S-parameter sweep, inspect S11 on a Smith chart, tune L and C, and verify bandwidth.
Application workflow
Run the matching loop in Tersa EDA
Use the real product flow to move from a circuit and reference impedance to measured reflection, component tuning, and a verified frequency sweep.
Define the impedance and the design target
Start at the reference plane that matters and record the complex load impedance Z = R + jX at the target frequency. Confirm the system reference impedance Z0, commonly 50 Ω in RF work. The reflection coefficient Γ = (Z − Z0) / (Z + Z0) connects that impedance to S11. A match is therefore a measurable target, not simply a schematic that contains an inductor and capacitor.
- State the target frequency and required bandwidth
- Use the correct reference plane and Z0
- Record resistance and reactance, not magnitude alone
- Set an S11, return-loss, or VSWR acceptance limit
Choose a network that fits the circuit
An L-network uses two reactive elements and is a useful narrow-band starting point when one resistance must be transformed to another. Low-pass and high-pass arrangements can both produce a match at one frequency, but they differ in harmonic response, DC continuity, component values, and sensitivity. Wider bandwidth or stronger harmonic control may require pi, T, transformer, or transmission-line structures.
- Choose topology before optimizing values
- Respect bias and DC-blocking requirements
- Avoid values near component self-resonance
- Include finite Q and package parasitics when possible