MatchLab

1. Antenna file

Or a CST export bundle (.zip with S-parameters and efficiency)

Choose a Touchstone file (S-parameters of your antenna).

1b. Antenna efficiency (optional)

Unlabeled files contain Include antenna efficiency in all results

Radiation efficiency of your antenna (CST or similar table, one file per port or a summary table), or far-field radiation patterns (.ffd / .rpf with a summary .xml). Without it, results assume a lossless antenna.

1c. Single-port or multiport

Single-port (uses port 1 only) Multiport (all ports solved together)

2. Bands and goals

Sweep from (MHz)to (MHz)

Pass / fail targetsEfficiency ≥ (%)S11 ≤ (dB)Judge targets by

Saved band setsName

Band sets are kept in this browser only.

2b. Search settings

Number of parts Search effort Score domain Weight within band0.05Weight across bands0.10 Prefer simpler (smaller-value) circuits within

3. Parts library

InductorsInductor tolerance CapacitorsCapacitor tolerance

Inductor range (nH)Capacitor range (pF)

Or use my own inductor files (.s2p, 2-port series data)Or my own capacitor files (.s2p)

Own files replace the vendor library for that part type. They are used for this session only and are not stored.

Ranked circuits

#	Circuit	Parts	Score	Band avg efficiency (min–max)	Worst S11

Tune the selected circuit

Swap each part for a neighbouring value from the library and watch the curves and score update. The faded line is the original circuit.

Smith chart (S11 of the selected circuit)

Target bandsVSWR ring (2:1)Admittance grid

Hover over the curve to read frequency, impedance and VSWR.

Markers

Frequency (MHz)Return-loss level (dB)

Export this circuit

Exports use the circuit as currently tuned. The zip contains parts list, response data, matched S11 Touchstone, SPICE-style netlist, summary and report. The CST macro builds the circuit in CST's schematic.

Bandwidth potential of this antenna

How wide a band an ideal lossless two-component match could reach at each frequency. Uses only the antenna data.

Return loss better than (dB)MethodSmallest capacitor (pF, blank = default)Show as

Compare circuits

Run history (this session and saved projects)

#	Time	Setup	Best circuit	Best score

Monte Carlo yield (for the selected circuit)

TrialsDistributionPass if band efficiency drops by no more than (dB)Min. band efficiency, optional (dB)Tolerance for all parts, optional (±%)Seed

Does not use up a search.