A ferrite bead is an example of a high resistance choke that impedes high-frequency electrical noise in electronics. The ferrite is used to control electromagnetic fields and generate the required magnetic field in a semiconductor device. Ferrite beads are capable of retaining their ferromagnetic properties even when they come in contact with a strong magnetic field, which makes them a potential electrical insulator. The use of ferrite in electrical wiring is common in microwave receivers, TV audio equipment, and computer interface devices. Ferrites can also be used in dental applications where braces are made from the hard coating of the ferrite bead.

When designing an electrical system or application, it is often necessary to exploit the inherent directional bias current capability of the ferrite bead. One way to accomplish this is to control the input impedance value of the circuit by changing the bias current setting of the ferrite bead. Another method of turning the inherent DC bias current into a DC current that is linearly proportional to the input current is the use of the two-side AC to DC power supply control. By the use of a diode, one side of the current will be linearly based upon the desired output voltage. In most cases, the two-sided AC to DC power supply control is used with a one-sided switch that allows the switching of the bias current between different levels of DC currents.

An important DC bias current value that can be exploited with the use of the ferrite bead is the inductance. This is an electrical characteristic that measures the amount of induction that can occur in a conductor. The more the inductance, the higher the inductance currents produced. The figure that is derived from the equation (I=L/R) is called the Inductance. The higher the inductance current, the smaller the alternating currents produced. There are many other inductance values that can be exploited through the use of the ferrite bead.

Some of the active device components that can be effectively implemented through the use of the ferrite beads are the so-called passive devices. These are very useful in the generation of the passive device filtering high frequency power supply noise. The effective filter of high frequency power supply noise is often considered as the best filter for the passive device filters.

The final passive device component is the so-called resonant frequency division multiplexer. This is a low impedance device that uses the two-sided AC to drive the high frequency inverters that can effectively lower the noise currents. The low-impedance DC to AC multiplexer is connected in series to form the first phase of the passive filtering high frequency power supply noise filtering circuit design. The second phase of the multi crossover RF source is connected in series to the second winding of the inductance. It is in this way that the entire circuit is implemented as a single-step filtering system.

For the purpose of providing an easy and quick method of building the passive filtering, the simplified circuit construction method is preferred. For the induction method, it is necessary to build the entire filtering system on a printed circuit board or through the use of a direct contact solid oxide electric field device. In case of the printed circuit board construction, the ferrite beads are preloaded into a thin horizontal dimension aluminum oxide insulator. Through the use of the soldering gun, the two metallic layers of the ferrite beads are bonded together to form the inductor core. The preloaded ferrite beads then become the foundation for the passive filter elements of the simplified circuit.