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10x100mm Axial Lead Ferrite Rod Coil Antenna for AM Radio and Induction Cookers - China Suppliers Factory Direct
Application
Access Control
ISO Card
Non-contact Smart Card
Door Number
Electronic Pen
Rf Transceiver Module
Trackable Device
Agriculture
Gps
Etc.
Features
For the testing of more than 10 wires such as pinholes, uniformity, and meter resistance, the standards are far higher than the industry average level.
More detailed information
Antenna Coil Manufacturing Process
The antenna coil structure consists of two sets of unconnected coils wound around a magnetic rod, forming the antenna coil used in the input circuit of a radio. Two independent coils form a high-frequency transformer. Soft magnetic ferrite materials are mainly classified into manganese zinc ferrite, nickel zinc ferrite, high conductivity manganese zinc ferrite, etc.
The antenna magnetic rod coil is a high-frequency transformer composed of a magnetic rod and a coil. The coils you see wound on a magnetic rod are usually divided into two groups:
- Primary coil: Forms a tuning circuit with a variable capacitor, used to select the radio frequency you want to listen to.
- Secondary coil: By coupling, the selected signal is transmitted to the next stage circuit of the radio for amplification processing.
Working Principle (Decomposed into two key steps)
- 1. Collection and aggregation (function of magnetic rod): The magnetic rod is made of a soft magnetic material called ferrite, which has a high magnetic permeability. You can imagine it as a "funnel" specifically designed to collect magnetic field lines. When electromagnetic waves pass through space, the magnetic rod can efficiently "attract" and "gather" the scattered magnetic field lines in a wide range around it onto itself.
- 2. Induction and enhancement (the role of coils): Due to the magnetic field lines being tightly confined within the magnetic rod and passing through the coils wound around the magnetic rod, according to the principle of electromagnetic induction, much higher voltage signals can be induced in the coils than without the magnetic rod. This is equivalent to greatly enhancing the antenna's "perception ability" for weak signals, thereby significantly improving the receiving sensitivity.
Structure and Materials
Simply put, it is a magnetic rod made of a special magnetic material (ferrite) inserted into the hollow coil. This magnetic rod plays the role of an "energy harvester" and a "signal amplifier", greatly enhancing the coil's ability to receive electromagnetic waves.
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Magnetic rod: Depending on the operating frequency, the material of the magnetic rod also has a division of labor.
• Medium wave magnetic rod: usually black in color, made of manganese zinc ferrite, with high magnetic permeability, suitable for lower frequencies (~1.6MHz).
• Shortwave magnetic rod: usually brown or gray in color, made of nickel zinc ferrite, with low magnetic permeability, but can operate at higher frequencies (~30MHz) with low high-frequency losses. - Coil: In order to reduce the losses caused by the "skin effect" of high-frequency currents, medium wave coils are often wound with multiple strands of yarn. Short wave coils are commonly wound with silver plated copper wire (leaving gaps between circles) to further reduce losses and distributed capacitance.
Application field
- Wireless communication: features: miniaturization, high efficiency, anti-interference, applied to IoT sensors, underground/pipeline communication, near-field communication (NFC)
- Wireless charging: features: improves transmission efficiency, reduces device size, applied to consumer electronics (mobile phones, watches), medical implant devices, industrial sensors
- New antenna: features: breaking through traditional size limitations, achieving ultra-low frequency communication, applied in ground penetrating communication, pipeline robot positioning, underwater communication
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Frequently Asked Questions
What are the primary applications of these antenna coils?
Antenna coils are widely used in wireless communication systems, access control systems, ISO cards, non-contact smart cards, door numbers, electronic pens, RF transceiver modules, trackable devices, GPS systems, and agricultural monitoring equipment.
How is the quality of the coils and wires tested?
We perform rigorous testing of more than 10 wire parameters, including pinholes, uniformity, and meter resistance, ensuring our quality standards are far higher than the industry average.
What is the difference between primary and secondary coils?
The primary coil forms a tuning circuit with a variable capacitor to select specific radio frequencies. The secondary coil couples with the primary coil to transmit the selected signal to the next stage circuit for amplification.
Why are different materials used for medium wave and shortwave magnetic rods?
Medium wave rods use manganese zinc ferrite for high magnetic permeability at lower frequencies (~1.6MHz). Shortwave rods use nickel zinc ferrite to minimize high-frequency losses at frequencies up to ~30MHz.
How do the magnetic rod and coil work together to enhance signals?
The high-permeability magnetic rod acts as a funnel to collect and concentrate magnetic field lines. The coils wound around it then induce significantly higher voltage signals via electromagnetic induction, dramatically improving receiving sensitivity.
What is the purpose of winding coils with multiple strands of yarn or silver-plated wire?
Winding with multiple strands of yarn (for medium wave) or silver-plated copper wire with gaps (for shortwave) reduces skin effect losses and distributed capacitance in high-frequency currents, ensuring maximum transmission efficiency.