Air Coils

DEFON Electronics Air Wound Coils – High-Frequency Precision Without Magnetic Core Losses

In high-frequency circuit design, traditional magnetic cores can introduce losses, nonlinearity, and stability issues that degrade performance. DEFON Electronics addresses these challenges with our precision air wound coils (also known as air core coils) — inductors engineered without magnetic cores, using instead non-magnetic materials that preserve signal integrity at the highest frequencies.

What Are Air Wound Coils?

Air wound coils are a specialized type of inductor that deliberately omits the magnetic core found in conventional inductors. Instead, wire is wound around or supported by non-magnetic materials such as:

• Air: Self-supporting coils with no internal form, offering the lowest possible core losses and highest frequency performance.

• Plastic: Coils wound on plastic forms for mechanical stability while maintaining non-magnetic properties.

• Ceramic: High-temperature stable ceramic forms for applications requiring precision and thermal stability.

• Glass: Ultra-stable glass forms for applications demanding minimal thermal expansion and maximum dimensional stability.

By eliminating the magnetic core, these inductors avoid core losses, hysteresis effects, and saturation limitations that plague conventional inductors at high frequencies. The result is a component with:

• Exceptional High-Frequency Performance: No core losses means performance extends to much higher frequencies.

• Excellent Linearity: Without magnetic materials, there is no saturation or hysteresis — inductance remains constant regardless of current.

• High Q Factor: Low losses result in high quality factor (Q), critical for resonant circuits and filters.

• Temperature Stability: Non-magnetic materials offer predictable, stable performance across temperature.

Where Are Air Cores Used?

DEFON air core coils are specifically designed for high-frequency circuits that need precise, stable inductors without the limitations of magnetic cores. They find application across a wide variety of industries and applications:

• Power Supplies: High-frequency resonant converters, LLC converters, and wireless power transfer systems requiring low-loss inductors at MHz frequencies.

• Test Equipment: Precision signal generators, network analyzers, and impedance bridges requiring accurate, stable inductance.

• Medical Electronics: MRI systems, RF ablation equipment, and therapeutic devices operating at radio frequencies.

• Manufacturing Equipment: RF plasma generators, induction heating systems, and industrial processing equipment.

• Telecommunications: RF filters, impedance matching networks, and antenna systems for wireless infrastructure.

• Broadcast Equipment: High-power RF amplifiers, transmission line matching, and studio-to-transmitter links.

• Research and Development: Laboratory experiments, prototype circuits, and custom instrumentation requiring precise inductors.

• Aerospace and Defense: Radar systems, electronic warfare equipment, and secure communications operating at high frequencies.

Advantages of DEFON Air Wound Coils

DEFON air core coils offer specific advantages for demanding high-frequency applications:

• No Core Losses: Without magnetic material, there are no eddy current or hysteresis losses, even at the highest frequencies.

• No Saturation: Inductance remains constant regardless of current — no sudden drop in performance at high currents.

• Excellent High-Frequency Response: Performance extends well into MHz and even GHz ranges.

• High Q Factor: Low losses result in high quality factor, essential for resonant circuits and narrowband filters.

• Predictable Performance: Simple geometry allows accurate calculation and modeling of electrical characteristics.

• Thermal Stability: Non-magnetic materials offer stable performance across wide temperature ranges.

• Low Distortion: No magnetic nonlinearity means clean signals without harmonic generation.

Air Core vs. Magnetic Core: Making the Choice

Understanding when to choose air core versus magnetic core inductors is essential for optimal circuit design:

DEFON Electronics manufactures both air core and magnetic core inductors, allowing our customers to select the optimal technology for each application.

Design Considerations for Air Wound Coils

When designing with air core coils, several factors influence performance:

• Wire Gauge and Type: Heavier gauge wire reduces DC resistance; litz wire can reduce AC resistance at high frequencies.

• Coil Geometry: Diameter, length, and turn spacing determine inductance and self-resonant frequency.

• Support Material: Choice of form material affects thermal stability and mechanical robustness.

• Termination Style: Proper terminations minimize parasitic effects and ensure reliable connections.

• Proximity Effects: Nearby conductive materials can affect inductance and Q.

DEFON engineering team works with you to optimize these factors for your specific application requirements.

Technical Specifications

DEFON Electronics offers air wound coils in a range of configurations to suit diverse application requirements:

• Size Range / Form Factor: Available in a broad range of sizes and configurations, including self-leaded, surface mount (SMT), and through-hole terminations to accommodate various PCB layouts and assembly processes. Custom geometries available for specialized requirements.

• Output Range: Built to meet industry standards and customer requirements, with custom electrical specifications tailored to your application’s frequency, inductance, and current needs.

• Inductance Range: Custom values from nanohenries to microhenries, optimized for high-frequency performance.

• Q Factor: High Q designs available for resonant circuit applications.

• Self-Resonant Frequency: Optimized for operation well below self-resonance for predictable performance.

• Operating Temperatures: Available with 130°C and 155°C temperature ratings to suit various operating environments.

• Packaging Options: Available in tray and bulk packaging for prototype and production quantities.

Compliance and Standards

DEFON Electronics is committed to manufacturing products that meet industry standards for quality and environmental responsibility:

• IPC-A-610: Manufactured in accordance with IPC-A-610 acceptability standards for electronic assemblies, ensuring consistent quality and reliability.

• RoHS3 and Conflict-Free: All coils comply with RoHS3 environmental standards and Conflict-Free sourcing requirements, supporting ethical and sustainable supply chains.

Custom Engineering for Your Specific Requirements

At DEFON Electronics, we understand that high-frequency applications often require specialized inductor designs. Our engineering team works closely with you to develop custom air wound coils that meet your exact specifications:

• Custom Inductance Values: Precisely calculated and wound to achieve target inductance at your operating frequency.

• Optimized Q Factor: Designs tuned for maximum Q at your specific frequency of interest.

• Mechanical Customization: Custom diameters, lengths, and terminations for unique mounting requirements.

• Specialized Wire Types: Litz wire, silver-plated wire, or other specialized conductors for demanding applications.

• Support Material Selection: Choice of plastic, ceramic, glass, or self-supporting designs based on your requirements.

Why Choose DEFON Electronics for Air Wound Coils?

With over decades of combined experience in coil manufacturing and magnetic component design, DEFON Electronics understands the unique challenges of high-frequency circuit design. We combine precision winding capabilities with deep technical expertise to deliver air core coils that provide exceptional performance, consistent quality, and long-term reliability.

From initial concept and prototyping to full-scale production, we partner with you to ensure your high-frequency applications achieve optimal performance.

Get Answers to Your Questions About Air Wound Coils

We know you may have questions about air wound coils and whether they are the right choice for your application. Please don’t hesitate to contact us with them. DEFON Electronics has extensive experience in the coils contract manufacturing business, so we are well prepared to give you the answers you need.

Contact DEFON Electronics today to discuss your air wound coil requirements. Our engineering team is ready to assist you with technical questions, custom designs, and production requirements.