Air-core inductor - Project Details

An air-core inductor coil is an inductive component characterized by a coreless structure, relying entirely on the self-inductance effect of its wire windings for operation. It holds an irreplaceable status in high-end applications such as 5G base stations (28/39 GHz bands), particle accelerators (generating pulsed magnetic fields > 10 T), and qubit readout circuits.

Video

Technical Specifications

❖ Hysteresis Loss: 0

❖ Saturation Current: Theoretically infinite (no magnetic saturation)

❖ Q-Value: (at 1 MHz) 150–400

❖ Temperature Coefficient: +0.003%/℃ (due solely to copper resistance effects)

❖ Self-Resonant Frequency (SRF): Typically > 50 MHz

Applications

❖ High-Frequency Communication Systems: 5G/6G base stations, satellite communications

❖ Precision Measurement Instruments: Current sensors, quantum measurement devices

❖ Medical Electronic Equipment: MRI gradient coils, high-frequency electrosurgical units, implantable neurostimulators

❖ Defense and Aerospace: Radar systems, spacecraft systems

❖ New Energy and Power Electronics: Photovoltaic inverters, electric vehicles (EVs), on-board chargers (OBCs), etc.

Considerations

❖ Winding Method: Single-layer close-winding (contiguous or spaced) or multi-layer winding; the choice affects parasitic capacitance and inductance.

❖ Wire Selection: Use Litz wire for high-frequency applications to minimize the skin effect.

❖ Shielding Requirements: Air-core coils are susceptible to interference from external magnetic fields; shielding enclosures should be added when necessary.