RF Term
Numerical Aperture
Numerical Aperture is a concept in RF and microwave engineering. This term is commonly encountered in the design, analysis, and testing of radio frequency systems and components. A comprehensive technical definition with formulas, comparison tables, and FAQs will be added in a future update.
Key Equations
Numerical aperture:
NA = ncoresinθmax = √(ncore²−nclad²)
Acceptance angle:
θmax = arcsin(NA/n0)
Number of modes:
V = (2πa/λ)×NA
Single mode: V < 2.405
Number of modes ≈ V²/2 (step-index)
NA = ncoresinθmax = √(ncore²−nclad²)
Acceptance angle:
θmax = arcsin(NA/n0)
Number of modes:
V = (2πa/λ)×NA
Single mode: V < 2.405
Number of modes ≈ V²/2 (step-index)
Comparison
| Fiber | NA | θmax | Modes @850nm | Application |
|---|---|---|---|---|
| SMF (G.652) | 0.12 | 6.9° | 1 | Long haul |
| MMF OM3 | 0.20 | 11.5° | ~800 | Data center |
| MMF (62.5μm) | 0.275 | 16° | ~1500 | Legacy LAN |
| Plastic (POF) | 0.50 | 30° | ~100000 | Short link |
| High-NA fiber | 0.35–0.50 | 20–30° | Many | Sensors/medical |
Overview
Numerical Aperture plays a role in modern RF and microwave system design. Understanding this concept is important for engineers working with radio frequency circuits, antennas, signal processing, and electromagnetic compatibility. This page will be expanded with detailed technical content, engineering equations, comparative reference tables, and frequently asked questions.
See Also