Classification of High-Frequency Transformers

High-Frequency Transformers (HFTs) are transformers used in high-frequency circuits, serving purposes like voltage conversion, power transmission, and signal isolation in electronic devices. High-frequency transformers can be classified based on different criteria; below are some common classification methods:

1. Classification by Operating Frequency:

• Low-Frequency Transformers: Operating frequency typically ranges from tens of Hertz to several kilohertz.

• Medium-Frequency Transformers: Operating frequency ranges from several kilohertz to tens of megahertz.

• High-Frequency Transformers: Operating frequency ranges from tens of megahertz to several gigahertz.

2. Classification by Magnetic Material:

• Iron-Core Transformers: Use an iron core for the magnetic circuit, including silicon steel laminations, powdered metal cores, etc.

• Coreless Transformers: Use air, magnetic plastics, or other non-ferromagnetic materials for the magnetic circuit.

3. Classification by Construction Type:

• Conventional Transformers: Feature the typical structure with coils and an iron core.

• Planar Transformers: Employ planar windings and core structures, offering a smaller volume.

• Toroidal Transformers: Have windings and a core arranged in a ring shape, suitable for high-frequency applications.

• Magnetic Core Transformers: Utilize magnetic materials as the core to enhance magnetic flux density and efficiency.

4. Classification by Application Field:

• Power Transformers: Used for power conversion, such as converting AC to DC at different voltage levels.

• Signal Transformers: Used for signal transmission and isolation, e.g., in communication and broadcasting equipment.

• Magnetic Components: Serve as magnetic circuits in high-frequency circuits, potentially lacking distinct transformer characteristics.

5. Classification by Encapsulation Form:

• Open-Frame Transformers: Lack a housing or encapsulation, suitable for Surface Mount Technology (SMT).

• Encapsulated/Enclosed Transformers: Have a housing or encapsulation, providing better electromagnetic compatibility (EMC) and mechanical protection.

6. Classification by Cooling Method:

• Air-Cooled Transformers: Cooled via natural air convection or forced air cooling.

• Liquid-Cooled Transformers: Utilize liquid cooling systems to improve thermal efficiency.

Different types of high-frequency transformer designs are intended to meet specific application requirements, including considerations for power, frequency, efficiency, size, and cost. When selecting a high-frequency transformer, design engineers need to choose the appropriate product based on the specific requirements of their application.