37-EFT.WP.EDX.HighSpeed v1.0 | Chapter 16 — Design Protocols & Engineering Checklist

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Chapter 16 — Design Protocols & Engineering Checklist

I. Chapter Objectives & Scope

1. Objective: Consolidate the path → arrival → mode → impedance → radiation-correction stack of the HighSpeed volume into an executable design protocol and engineering checklist, with coherence-window KPIs (E_phase/GDR/ΔW) and positive-real/causality gates as core controls, ensuring Z_eft(omega), T_arr, and T_group are consistent and releasable.
2. Scope: Microstrip/stripline, differential pairs, vias/plane bridges, connectors/launches, board–cable transitions, and shielding structures across the coherence window Ω and its neighborhood.
3. Shared time-of-arrival dialect (equivalent; explicit path/measure; record delta_form):
   • Constant-factored: T_arr = ( 1 / c_ref ) * ( ∫ n_eff d ell )
   • General: T_arr = ( ∫ ( n_eff / c_ref ) d ell )

II. Golden Rules

• Phase-linearity principle: subject to impedance balance, minimize the in-band slope and ripple of
  Σ_p w_p · ∫_{γ_p} n_eff d ell (quantified by E_phase/GDR).
• Return-path priority: provide local closed returns and stitching-via rings at layer/plane transitions to suppress w_side(ω) and ΔT_arr.
• Positive-real radiation gate: when the radiation channel is enabled, require Re{ΔZ_rad(ω)} ≥ 0 and expect reduction after sealing/optimization.
• Window governance: perform coherent summation inside the window and control KPIs; outside use energy composition—no extrapolation of in-window models.
• Port-normalization consistency: unify Znorm(ω)/mixed-mode basis before S→Z mapping; after mapping pass passivity / KK.
• Two-dialect agreement: for the same γ(ell)/n_eff, the two T_arr writings must differ ≤ u(T_arr) (hard gate).

III. Engineering Workflow (six executable stages)

• Requirements & band: define Ω=[ω1,ω2], KPI targets, radiation gates, and compliance interfaces; produce a requirement card and initial qa_gates.
• Topology & path/mode prototype: annotate γ_main/γ_side and mode set 𝓜; estimate T_arr and w_{p,m} trends; produce a prototype binding card.
• Layout & process: implement return paths/stitching vias, radius bends, length-matched splits, tapered launches with ground fingers, back-drilled stubs; produce binding_ref and geometry tables.
• Metrology plan & alignment: port harmonization → de-embed & renorm → S→Z mapping → sync correction → path correction → window evaluation; produce a metrology_hf card.
• Prototype iteration & falsification: measure/3D-EM → KPIs & J-series criteria → if fail, close the loop via the failure-mode table.
• Release & hand-off: freeze baseline_id & binding_ref; deliver dataset/pipeline/env_lock/audit and the acceptance card.

IV. Layout/Process ↔ Path/Mode Rules (verifiable)

• Returns & stitching: ring/grid stitching; via pitch ≤ 20×H (trace height); add via bridges for plane cuts and include in γ_p.
• Microstrip/stripline/differential: back-solve W/S from target Z_c(ω) and record; differential pairs length-match, stable coupling, no right-angle bends.
• Bends & splits: r ≥ 3W; symmetric, length-matched splits with return grids; constrain coupling matrix |C_{mn}|.
• Vias & stubs: control barrel/stub; prefer back-drill; provide near return-via groups at bridges; enable γ_side and link ΔZ_rad.
• Connectors/launches: tapered transitions, optimized ground fingers; mixed-mode normalization → back-project; check ΔZ_c(Ω) and KPIs.
• Shielding/apertures: avoid long seams; if necessary, mesh/periodicize and record sigma_seam; after sealing, Re{ΔZ_rad} and field levels decrease.
• Board–cable transitions & PI grid: pair returns in bundles; near-end decoupling and low-impedance returns; avoid large voids.

V. KPIs & Acceptance Gates (aligned with Chapter 7)

• Engineering: E_phase ≤ 0.08 rad, GDR ≤ 0.25 ns, ΔW ≤ 0.30; if radiation enabled, Re{ΔZ_rad} ≥ 0.
• Release: E_phase ≤ 0.05 rad, GDR ≤ 0.20 ns, ΔW ≤ 0.20; all passivity/K–K gates pass.
• Supplemental targets like ΔZ_c(Ω) and |S11|/|S21| may be detailed in dataset cards.

VI. Records & QA (aligned with data/pipeline cards)

• Required: binding_ref, arrival{form,gamma,measure,c_ref,Tarr,u_Tarr,delta_form}, Z_c(ω), E_phase/GDR/T_group/ΔW, (if enabled) ΔZ_rad with Re_Zrad_min, qa_gates{check_dim,passivity,KK}.
• Versions/hashes: record versions & sha256 of S→Z renorm/de-embed/mixed-mode matrices.
• Hard gates: two-dialect T_arr agreement; Re{Z_eft} ≥ 0; KK = pass; if radiation enabled, Re{ΔZ_rad} ≥ 0.

VII. Implementation Binding & Co-Work (I30-HF / I40-HF / Mx-*)

• I30-HF: bind_layout_hf / mode_project / mode_merge / path_correct_hf.
• I40-HF: map_S_to_Z / em_port_align / cosimulate.
• Mx- (inversion):* invert / ppc / evidence; evidence first, parsimony second; PPC residuals near-white as a pass criterion.

VIII. Tolerances & Robustness (DFM/DFA)

• Feed tolerances on width/dielectric thickness/copper thickness/via geometry as ±σ into SimStack to compute KPI tolerance sensitivities; tighten layout windows for high-sensitivity terms.
• Acceptance: Monte Carlo KPI pass rate ≥ 95% (project-specific).

IX. Falsifiability (for the Design Protocol)

• J-DR-HF-1 (Return path): if stitching/bridging fails to improve ΔW and E_phase/GDR, reject the return strategy or γ annotation.
• J-DR-HF-2 (Via stubs): if back-drill/trim does not reduce Re{ΔZ_rad} and field levels, reject radiation equivalence or geometry inputs.
• J-DR-HF-3 (Mixed-mode renorm): if post-normalization/mapping fails passivity/K–K, reject port basis or renorm config.
• J-DR-HF-4 (Tolerance robustness): if Monte Carlo pass rate < gate, reject geometry/process windows.
• J-DR-HF-5 (Two-dialect agreement): if |T_arr^{(1)}−T_arr^{(2)}| > u(T_arr), reject release.

X. Compliance Templates (copy-ready)

• Design acceptance card (YAML)
• design_protocol_hf:
• project_id: "EDXHS-PRJ-001"
• binding_ref: "LAY2PATH-HF-0001"
• baseline_id: "BLSN-EDX-001"
• bands:
• - {w1: ω1, w2: ω2}
• arrival:
• form: "n_over_c" # or "one_over_c_times_n"
• gamma: "explicit"
• measure: "d_ell"
• c_ref: 299792458.0
• Tarr_s: 1.234e-09
• u_Tarr_s: 6.0e-12
• delta_form: "n_over_c"
• primitives:
• returns: {stitch_ring: true, pitch_mm: 2.0}
• bends: {radius_rule: "≥3W", right_angle: false}
• vias: {backdrill: true, max_stub_mm: 0.5}
• launch: {tapered: true, ground_fingers: "optimized"}
• shields: {mesh: true, seam_pitch_mm: 3.0}
• targets:
• Zc_ohm: 50.0
• E_phase_rad: {eng: 0.08, rel: 0.05}
• GDR_s: {eng: 0.25e-9, rel: 0.20e-9}
• ΔW: {eng: 0.30, rel: 0.20}
• Re_Zrad_min: 0.0
• qa_gates: ["check_dim","passivity(Re{Z}≥0)","KK_consistency"]
• signoff:
• design_owner: "..."
• metrology_owner: "..."
• date: "2025-09-16"
• Acceptance script (pseudocode)
• # KPIs
• phi = unwrap(argZ - ω*Δt_sync)
• T_group = grad(phi, ω)
• E_phase = max_abs(phi - (ω*Tarr + φ0_opt))
• GDR = max_abs(T_group - median(T_group))
• # ΔW
• ΔW = sum_abs(w[p,m](ω2) - w[p,m](ω1) for p,m in paths_modes)
• # Radiation gate
• if radiation_enabled:
• assert min(Re(ΔZ_rad)) >= 0.0
• # Two-dialect agreement
• assert abs(Tarr_n_over_c - Tarr_one_over_c_times_n) <= u_Tarr
• # Hard QA
• assert min(Re(Z_eft)) >= 0.0 and KK_consistency(Z_eft)
• # Pass
• assert E_phase <= E_phase_gate and GDR <= GDR_gate and ΔW <= ΔW_gate

XI. Quick Troubleshooting & Remedies

• Phase non-linearity: shrink Ω; optimize γ_main and returns; suppress modal conversion & w_side.
• Group-delay ripple: smooth priors (n_eff/σ_eff) and de-couple; correct Δt_sync.
• Passivity/causality failure: band-limit kernels; re-check de-embed/renorm & Znorm; remove right-half-plane poles.
• Radiation over target: seal gaps/trim stubs/optimize shielding; re-validate Re{ΔZ_rad} and field levels.
• Two-dialect mismatch: verify delta_form/units/γ(ell) records; recompute discrete integrals.
• Tolerance failure: tighten geometry windows, densify stitching/returns, raise manufacturing capability grade.

XII. Execution Checklist

checklist_hf:

- [ ] Define Ω and KPI targets (E_phase/GDR/ΔW)

- [ ] Create binding_ref; annotate γ_main/γ_side and modes

- [ ] Fill arrival (form/gamma/measure/c_ref/delta_form)

- [ ] Complete deembed/renorm/S→Z/phase_corr/path_correct

- [ ] Compute Z_eft/argZ/T_group/E_phase/GDR/ΔW

- [ ] Radiation evaluation (ΔZ_rad ≥ 0 and decreases after sealing)

- [ ] Falsification criteria (P1–P4, J-DR-HF-*) passed

- [ ] Two-dialect T_arr agreement (≤ u_Tarr)

- [ ] Archive dataset/pipeline/env_lock/audit (sha256)

- [ ] Sign-offs by design / metrology / QA

XIII. Cross-Chapter Links & Closure

• Dependencies: Chapter 4 (S20-HF/S30-HF dispersion), Chapter 5 (S50-HF radiation), Chapter 6 (S40-HF modes/primitives), Chapter 7 (KPIs), Chapter 8 (S↔Z mapping), Chapters 9–11 (metrology/falsification/co-sim), Chapter 15 (data & reproducibility).
• Closure: This chapter threads path → arrival → mode → impedance → radiation → metrology → data compliance into sign-off clauses, enabling predictive, tunable, and falsifiable engineering deployment at scale.