RF Ingress and EMI and RFI shielding

Latest technology of wireless and wired telecommunication when come into close proximity with powerful stations like AM, FM and TV broadcast facilities lead to interference problem from high level RF ingress into receiving, control and switching equipment. Not only this, but RF ingress interference can also lead to service quality problems, dropping of calls, and test procedure difficulties.

Where the medical facilities are located in areas of high RF density, it can cause a risk of malfunction to sensitive patient and lab equipment.  Many a times facilities can become carrier of high level radio frequency energy from electro-surgical devices, diathermy equipment, linear accelerators, MRI equipment and other kinds of devices that may cause problem not only to collocated equipment, but to associated patient and worker health. Other problems occur from on-site security guard radios, mobile phones and vehicular radios.

Sealing, drying, baking and other operations of industrial sites can also be large generator of RF ingress. These RF environments potentially affect process control monitoring system and internal communication system.

Radio frequency modules are available widely in the market. RF module is a small electronic device used to transmit and or receive radio signals between two devices. In an embedded system it is often desirable to communicate with another device wirelessly. The wireless communication may be accomplished through optical communication or through radio frequency communication. For many applications the medium of choice is RF since it doesn’t require line of sight.

RF device are widely used in electronic design owing to difficulty of designing radio circuitry. They are most often used in medium and low volume of products for consumer application such as garage open doors, wireless alarm systems, industrial remote controls, smart sensor application and wireless home automation systems,

The various disadvantages of RF ingress are-

  1. Uncontrolled radiation of RF affects pre-adolescent children, pregnant women, elderly humans, patients with peace maker, small birds, flora fauna etc to a great extent.
  2. The areas near RF cellular towers have been observed with more lightening as compared to others.
  3. It also affects some of the fruits grown near the RF towers.
  4. As RF waves are both available both in LOS and non LOS regions of transmitter it can be easily intruded by hackers and crucial personal/official data can be decoded for malicious motives. In order to avoid this situation , radio frequency wave based transmission is used with highly secured algorithms such as AES, WEP,WPA. RF signal can also be modulated either using frequency hopping or spread spectrum techniques to avoid this kind of eavesdropping.

Benefits of RF shielding are-

  1. Reduced incidence of EMI induced performance degradation from existing and future radio frequency EMI sources.
  2. Reduces RF field levels to which building facility equipment is exposed by 99 to 99 percent and more.
  3. Produces protection against interfering signals, including AM, FM, TV, emergency services, dispatch, pagers, ESMR, cellular and PCS.
  4. Improved system operating efficiency.
  5. Enhanced overall system reliability.
  6. Reduced system maintenance.