Public evidence

electrical.rf.cascaded_nf

Machine-checked verification for calculation version 1.1.1 · tier internally_reviewed

Open calculator API Capability Download JSON CVP Manifest MCP Review policy

CVP status

No mismatch / image-noise extras. Last-stage gain does not enter F_tot. Arrays max 64 stages. MIXED_INPUT_ENCODING / NONCONTIGUOUS_STAGES.

Declared partition coverage: PASS · 8/8 declared partitions (nf-g-fields, arrays, n-ge-3, negative-gain, invalid-domain, mixed-encoding, noncontiguous-stages, linear-gain-overflow)
Versions: Calculation 1.1.1 · CVP protocol 1.0.0-proposed · Evidence 2026-09-12.exclusive-encoding-contiguous
Verification revision: 2026-09-12.exclusive-encoding-contiguous · 5/5 property · digest cffdb448177b

Verification

Legacy regression suite: 22/22 calculation tests · Production surface contract 6/6

Three distinct suites: educational examples on the calculator page, this legacy regression count (22/22 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.1.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-12.exclusive-encoding-contiguous. Calculation version 1.1.1. CVP 1.0.0-proposed. 5/5 golden · 12/12 CVP boundary · 16/16 invalid · 5/5 property · 1/1 metamorphic · 2/2 cross-interface · 4/4 CVP contract. digest cffdb448177b.

Golden (oracle-backed) 5 / 5
CVP boundary 12 / 12
Invalid input 16 / 16
Property 5 / 5
Metamorphic 1 / 1
Cross-interface 2 / 2
CVP contract 4 / 4
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session.
Assurance Engineering

release artifacts aligned PASS
schema output required declared PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS
rest success payload validates schema PASS

Fingerprint sha256:e499a69bf70cfd80b7dcd608cb849f615e1d54165b1f749836d2a276208a9ac0

Input schema sha256:bfb7a1226de15f901673da5b7e001c641f416e175640fe463850a6d56761ae1d · Output schema sha256:7df2c407d15f6a571ccf19a4e5ad5c0eeeed041efe0b9fcb75ba77483d71de62 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: cascaded-nf
Engine: cascaded-nf
Engine build: 2026-09-12
Evidence core: 2026-09-12T08:53:19.298Z
Rendered: 2026-11-10T05:18:41.742Z
Last reviewed: 2026-09-12

Assumptions

Matched stages
Gi denotes available power gain
NF and gain inputs are dB and are converted to linear factors internally
Classical Friis cascade assumptions apply
For a matched passive two-port at T0 ≈ 290 K, NF_dB = L_dB ≈ −G_dB

Limitations

Mismatch effects are not modeled
Image-noise / special mixer sideband behavior is not modeled
REST/MCP arrays NF_dB[]/G_dB[] are limited to 64 stages (TOO_MANY_STAGES); field encoding NF1…NF8 is limited to 8
Field encoding and array encoding are mutually exclusive (MIXED_INPUT_ENCODING); field stages must be contiguous from stage 1 (NONCONTIGUOUS_STAGES)
When 10^(G_tot_dB/10) overflows IEEE-754 binary64, G_tot_lin is null and LINEAR_GAIN_OVERFLOW is returned; G_tot_dB remains finite

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

Friis, H. T., “Noise Figures of Radio Receivers,” Proceedings of the IRE, Vol. 32, No. 7, pp. 419–422, July 1944 — Cascade formula · 1944-07 · DOI
Supports: F = F1 + (F2−1)/G1 + (F3−1)/(G1 G2) + … with Fi, Gi as linear power ratios (available gain)
Pozar, D. M., Microwave Engineering, 4th ed., Wiley, 2012 — Ch. 10 Noise and Nonlinear Distortion, §10.2 Noise Figure of a Cascaded System, p. 504 · 2012
Supports: Matched Friis cascade in the linear domain; available gain; cascade order

Verification disclosure

Aggregate outcomes, scope and artifact commitments are public. Complete test inputs, expected values, execution records and oracle infrastructure are retained privately. This summary does not independently reproduce the full verification run.