What Is Yield Analysis?
Manufacturing yield is the percentage of assembled units that meet all RF specifications. Component tolerances (±5% inductor, ±10% capacitor, ±0.05mm PCB trace) cause each unit to have slightly different performance. Yield analysis — most commonly Monte Carlo simulation — predicts this distribution before committing to production.
Step 1: Define Yield Criteria
Yield Pass/Fail Criteria (example LTE Band 8 matching network): ✓ S11 < −10 dB at 880–915 MHz (TX band) ✓ S11 < −10 dB at 925–960 MHz (RX band) ✓ S21 > −0.8 dB at band center (IL < 0.8 dB) A unit PASSES only if ALL three conditions are simultaneously met. This is the "yield specification" — define it before running Monte Carlo.
Step 2: Assign Component Tolerances
| Component | Standard Tolerance | Premium Tolerance |
|---|---|---|
| SMD Inductor 0402 | ±5% | ±2% (special order) |
| SMD C0G Capacitor | ±5% (standard), ±0.5 pF (small C) | ±1% |
| PCB trace width | ±0.05 mm (standard PCB) | ±0.025 mm (controlled-impedance) |
| X7R Capacitor | ±20% (also temperature-dependent) | ±10% |
Step 3: Run Monte Carlo in RF View
- Build circuit: DUT S2P + matching network in Circuit Simulator
- Switch to Tolerance Analysis tab
- Set each component's tolerance percentage
- Choose N = 500 runs (sufficient statistical accuracy)
- Tap "Run" → RF View generates 500 randomized circuits and simulates all
Step 4: Compute Yield
From 500 Monte Carlo runs:
Count traces meeting ALL pass criteria:
Pass (S11<−10dB in TX AND RX, IL<0.8dB): 463 of 500
Yield = 463 / 500 = 92.6%
Statistical confidence (95% CI for 463/500):
Lower bound: 89.9%, Upper bound: 94.8%
Target: Yield ≥ 90% → 92.6% passes ✓
If yield < 90%: redesign (lower Q, tighter tolerance components)
Step 5: Sensitivity Analysis
Run isolated tolerances to find which component limits yield: Fix all components at nominal, vary only L1: yield = 98.1% Fix all, vary only C1: yield = 95.2% Fix all, vary only PCB trace W: yield = 99.4% Conclusion: C1 is the most critical component → tighten to ±2% After change: overall yield improves from 92.6% to 96.3%
RF View Yield Analysis: Monte Carlo, sensitivity analysis, and visual spread plots — all in RF View's Tolerance Analysis tab. Free on Android. No additional simulation license needed.