Source: https://guthlabs.ai/docs/instruments/impedance-matching-network-designer-l-network/implementation/

instrument implementation / implementation-contract

# Impedance Matching Network Designer (L-network) implementation

A source-bound implementation contract for Impedance Matching Network Designer (L-network); deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t8-016

**Effect**: Computation or source lookup only

## Input and validation requirements

- Division by zero when source and load resistances are equal and the implementation evaluates R_high/Q.

- Invalid or nonphysical results if either resistance is zero, negative, non-finite, or if frequency is zero or negative.

- Ambiguous frequency units can produce errors of 10^3 or 10^6 in component values unless the UI and API enforce units.

- A single orientation label is insufficient unless it specifies the exact shunt location and reference direction for reactance signs.

- The ideal equations omit component Q, ESR, self-resonance, inductor winding resistance, capacitor ESR, PCB parasitics, bandwidth, and voltage/current limits.

- A match is not achievable with this simple two-reactive-element formulation for arbitrary complex source/load impedances unless additional complex-impedance equations and constraints are implemented.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "source_resistance_ohm": 50,
    "load_resistance_ohm": 200,
    "frequency_hz": 100000000,
    "network_orientation": "source_low_to_load_high",
    "solution": "series_L_shunt_C"
  },
  "expected_outputs": {
    "q": "sqrt(3) = 1.7320508075688772",
    "series_reactance_ohm": "50*sqrt(3) = 86.60254037844386",
    "shunt_reactance_ohm": "-200/sqrt(3) = -115.47005383792515",
    "series_inductance": "50*sqrt(3)/(2*pi*100000000) H = 137.8322 nH",
    "shunt_capacitance": "sqrt(3)/(400*pi*100000000) F = 13.7832 pF"
  },
  "reference_data": {
    "formula": "R_low=50, R_high=200; series L and shunt C",
    "frequency_unit": "Hz"
  },
  "working": "R_high/R_low=200/50=4. Q=sqrt(4-1)=sqrt(3)=1.7320508075688772. |X_series|=Q*R_low=sqrt(3)*50=86.60254037844386 ohm. |X_shunt|=R_high/Q=200/sqrt(3)=115.47005383792515 ohm. For the series-L/shunt-C solution, X_series=+86.60254037844386 and X_shunt=-115.47005383792515. L=X_series/(2*pi*f)=86.60254037844386/(2*pi*100000000) H=137.8322 nH. C=1/(2*pi*f*|X_shunt|)=1/(2*pi*100000000*115.47005383792515) F=13.7832 pF."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/impedance-matching-network-designer-l-network/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/impedance-matching-network-designer-l-network/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/impedance-matching-network-designer-l-network/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche8/tranche8-results.json`