RADIO FREQUENCY (RF) EMISSIONS & RF INTERFERENCE (RFI)

Radiofrequency interference has been around since the advent of the radio transmitter. In recent times with the proliferation of mobile devices and the Internet of things (IOT) RFI is becoming a bigger issue every day. In Europe the importance of protecting the consumer is reflected in the EMC Directive 2014/30/EU. This directive ensures that all equipment placed on the European market has an adequate level of radiofrequency immunity.

Typical victim circuits are sensitive transducers such as temperature and pressure sensors. Data processing equipment is vulnerable to transient disturbances which may be induced in circuits to create an illegal “1” or “0” thereby causing corruption of data.

Research facilities often have requirements for RF systems that require specially protected environments which are much lower than the limits applied in the EMC Directive. These systems have an inherent low susceptibility level and must be protected to ensure correct operation.

The most potent source of radio frequency interference is the mobile phone because of its ubiquity and possible proximity to the victim equipment. In high-intensity, high-density RF environments, interference is a constant worry and electromagnetic shielding can be required to ensure systems function properly.

Military systems not only are heavy users of RF Spectrum and can generate intense fields. CEI has strong expertise (we are also an accredited test laboratory) and extensive experience in RF systems, and the complex causes of RFI and effective solutions to RFI problems. Our consulting services help clients deploy effective RF-dependent systems through the analysis of existing environments for potential interference, providing design guidance to avoid problems, and designing/deploying electromagnetic shielding when necessary. RFI can present itself in environments where other EMI is a primary issue or RFI can be the entire problem. No company is better prepared to help with the full range of problem/solution areas related to RF/RFI than FMS.

STANDARDS, LEGAL, REGULATORY

Contrary to low frequency electric and magnetic fields, there are clear standards and regulations for RFI in Europe that are also applied throughout other parts of the world.

Typically standards listed under the EMC Directive 2014/30/EU for equipment intended for residential, commercial and light industrial environments requires a radio-frequency immunity level of 3 V/m. This provides an “adequate” level of protection – a mobile phone or walkie talkie can generate levels over 50 V/m in close proximity. Typical standards are IEC/EN 55035 for ITE.

For industrial environments the generic standard IEC/EN 61000-6-2 applies requiring immunity levels of 10 V/m.

Medical devices, which are potentially life supporting, have immunity levels up to 28 V/m in frequency bands used by mobile transmitters.

Military and automotive products are often tested to levels in excess of 100 V/m.

agsdi-layers

AC EMI Explained

agsdi-layers

DC EMI Explained

agsdi-layers

RF & RFI Explained

Compliance Engineering International is focused on providing value led engineering services across Europe. For almost twenty years we have been building our reputation as leaders in EMI mitigation and shielding services, focusing on projects in the science, research and healthcare, energy, commercial, education, transportation and government sectors.

Compliance Engineering International

Clonross, Dunshaughlin, Co Meath,
A85 XN59, Ireland

T: +353 1 8017000
F: +353 1 8256733

info@cei-compliance.com

training@cei-compliance.com