TABLE I.
EnerCage Coil Specifications Optimized at 13.56 MHz
| Parameter | Design Value | |
|---|---|---|
| Driver (L1) and primary (L2) hex-PSCs implemented on two double-layer FR4 PCBs in the stationary unit | Inductance = 0.68 μH | |
| Outer diameter = 16.6 cm | ||
| Number of turns = 2 | ||
| Line width = 8.66 mm | ||
| Line spacing = 2.60 mm | ||
| Q1 = 163 for driver PSC on layer 1 | ||
| Q2 = 127 for primary PSC on layer 2 | ||
| Q2 = 155 for primary PSC on layer 3 | ||
| Copper weight = 3.3 g | ||
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| ||
| Wire-wound secondary coil (L3) in the mobile unit | Inductance = 1.25 μH | |
| Coil diameter = 40 mm | ||
| Wire diameter = 0.64 mm (22 AWG) | ||
| Number of turns = 4 | ||
| Q3 = 196 | ||
| Copper weight = 1.4 g | ||
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| ||
| Multi-layer PCB load coil (L4) in the mobile unit | Inductance = 0.37 μH | |
| Coil diameter = 25 mm | ||
| Line width = 1 mm | ||
| Number of turns = 3 | ||
| Q4 = 177 | ||
| Copper weight = 0.3 g | ||
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| ||
| L2 and L3 maximum relative distance (d23) | 120 mm (k23 = 0.035) | |
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| L3 and L4 relative distance (d34) | 18 mm(k34 = 0.28) | |
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| Overall efficiency (%) at d23 = 120 mm Max/Ave/Min* | 12.2/8.3/6.2 (3-coil) | 12.6/7.9/5.6 (4-coil) |
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| Nominal loading (RL) (Ω) | 500 | |
*
Maximum misalignment in the worst-case PTE: γmax = 48.5 mm.