Wireless Charging Coils: Technical Breakdown by Goden Eagle
Publish Time: 2025-05-10 Origin: Site
Wireless Charging Coils: Technical Breakdown by Goden Eagle
1. By Winding Structure
▸ Flat Spiral Coils
Structure: Single/multi-layer planar design
Key Specs: 5-20μH inductance, 0.1-1.0mm wire diameter
Best For: Qi-standard devices (smartphones, wearables)
Advantage: Ultra-thin profile (<0.8mm) for compact designs
▸ Litz Wire Coils
Structure: Multi-strand twisted wire (typically 60-200 strands)
Key Specs: 10-30μH, AC resistance <50mΩ @100kHz
Best For: High-power 15W+ applications (tablets, tools)
Advantage: Reduced skin effect losses at 110-205kHz
▸ Multi-Coil Arrays
Structure: 3-18 coil matrix with overlapping zones
Key Specs: 5-15μH per subunit, ±5% positional tolerance
Best For: Free-position charging (e.g., furniture-embedded systems)
Advantage: 75%+ spatial efficiency vs single-coil designs
2. By Core Material
| Type | Permeability (μ) | Frequency Range | Typical Applications |
|---|---|---|---|
| Ferrite | 800-5,000 | 50kHz-1MHz | Qi-BPP/EPP receivers |
| Nanocrystalline | 10,000-50,000 | 20kHz-300kHz | Automotive 11kW systems |
| Air Core | 1 | 100kHz-6.78MHz | High-frequency A4WP |
3. Cutting-Edge Innovations
▶ Graphene-Enhanced Coils
18% lower Rdc than copper at 25°C
100W+ capability with <3°C temperature rise
▶ Hybrid DD+Tape Coils
Dual-mode for both Qi and MagSafe compatibility
85% alignment tolerance improvement
Technical Insight: Our 16-coil matrix module achieved 92% efficiency at 65mm Z-axis distance (vs industry avg. 78%) in automotive center console prototypes.
Golden Eagle's Customization Capabilities:
✓ Impedance Matching: Optimized for 6.78MHz/13.56MHz systems
✓ Shielding Solutions: Reduce EMI by 15dB (meets CISPR-32 Class B)
✓ Automotive Grade: AEC-Q200 compliant coils for 85°C ambient operation