Radio frequency interference (RFI) is interference that occurs at or very close to the frequency of the signal received by the receiver. The adverse effects caused by useless RF signals on the reception and processing of useful signals, which may lead to equipment performance degradation, data transmission errors, and even equipment failure or safety accidents.
Radio frequency is a type of high-frequency alternating current, commonly known as electromagnetic waves. Radio frequency interference is the interference caused by electromagnetic waves If two electromagnetic waves with similar frequencies are received by the receiver at the same time, there will be harmonic interference near the transmitting station, which will interfere with other receiving devices. Transmitting electromagnetic waves with the same frequency can interfere with enemy radio stations.
Radio frequency interference can disrupt and interfere with the normal operation of electronic and electrical equipment, so it is important to limit it whenever possible. Most electronic and electrical devices emit radio frequency interference, such as switch power relays, industrial controls, medical instruments, electronic printers, personal computers, laptops, game consoles, computing devices, etc. There are two types of radio frequency interference for electronic or electrical equipment: radiated radio frequency interference and conducted radio frequency interference. In the former case, interference is directly emitted from the device itself into the environment, while in the latter case, interference is released into the AC power line through the component or device’s power line. In the case of satellite communication, radio frequency interference can occur naturally or intentionally. Different forms of space weather, including solar storms, and appropriate shielding in equipment casings can help control radiated radio frequency interference. Power line filters can help control conducted Radio frequency interference (RFI) is the conduction or radiation of electrical noise or radio frequency energy generated by electrical and electronic devices, which can cause electronic or electrical equipment to produce noise that typically interferes with the functionality of adjacent devices. to a satisfactory and acceptable level. In the case of satellite communication, the use of high directional antennas and powerful end filtering can help solve narrowband RF interference. Modifying the source can help reduce interference in the presence of broadband interference.
RFI radio frequency interference, radio frequency is a high-frequency alternating current, also known as electromagnetic waves. Radio frequency interference is interference caused by electromagnetic waves. For example, two electromagnetic waves with similar frequencies can be simultaneously received by the receiver, causing interference. There will be harmonic interference near the transmitting station, which can interfere with other receiving devices. Transmitting electromagnetic waves with the same frequency can interfere with enemy radio stations. Radio frequency interference can disrupt and interfere with the normal operation of electronic and electrical equipment
Harmonics are electrical quantities in current with frequencies that are integer multiples of the fundamental wave. They generally refer to the Fourier transform series decomposition of periodic non sinusoidal electrical quantities. In addition to the ability to generate current at the fundamental wave frequency, they are called harmonics
Fundamental wave: The wave generated by a vibration is a sine wave with a certain frequency and the maximum amplitude. Wavelets with frequencies higher than the fundamental wave are called harmonics.
The fundamental cause of harmonic generation in the power system is due to nonlinear loads. When current flows through a load, it does not have a linear relationship with the applied voltage, resulting in non sinusoidal current, that is, harmonic generation in the circuit.
The RF interference in the power cord can be one of the following two modes:
- Symmetry or differential mode between lines;
- Asymmetric or common mode noise between the line and the ground.
How to reduce RFI interference in electrical systems:
There are regulatory requirements for the maximum amount of interference that electronic devices should emit. But there isn’t. RFI devices are impossible, and the best thing designers can do is to control and limit RFI to prevent it from interfering with nearby devices or devices sharing the same power cord.
Manufacturers should protect their equipment from interference from other devices or nearby devices on the same power source. In addition, interference from its equipment should be prevented from affecting nearby devices or devices sharing the same power system.
Shielding is one of the commonly used and effective methods to reduce the impact of radiated RFI. Power line filters can reduce conducted RFI and suppress conducted noise leaving the device. Line filters can also prevent imported RFI.
The use of RFI filters and other design methods at the input of electronic devices can help minimize incoming interference and prevent interference from returning to the power system through power codes. The RFI filter consists of a passive component network arranged with dual low-pass filters. This will be captured. RFI prevents signals from entering or leaving the device and attenuates RFI signals.
Reduce RF interference
There are different types of RFI filters available; Some are built into the power supply, while others are external. Some manufacturers integrate filters into AC sockets, as shown below. Integrated filters have standard sizes and are typically fixed at the power inlet of the power unit. This can ensure. RFI cannot enter or leave the power unit.
For power supplies that do not use connectors with filters, manufacturers typically include filter components in the power unit
Radio frequency interference (RFI) is the conduction or radiation of electrical noise or radio frequency energy generated by electrical and electronic devices, which can cause electronic or electrical equipment to produce noise that typically interferes with the functionality of adjacent devices.
