Electromagnetic Interference (EMI) occurs when electric currents, magnetic fields, and radio frequencies disrupt the energy flow of nearby electrical circuits. The most common offenders of EMI include computers, wireless devices, power lines, microwave equipment, and high-frequency electronics.
EMI may cause electrical noise, such as buzzing or static, but the greater concern is its ability to interrupt power supply, drop signals or prevent the transmission of data. A shielded cable connector can deflect EMI and prevent your electrical device from radiating EMI. Before you choose an interconnect solution, here are three things you need to know.
1. Shielded cables require shielded connectors to ensure that the ground and shield work properly.
Shielding a cable without also shielding the connector is only doing half the job. Your cable assembly cannot reach its maximum EMI coverage unless the connector shares a similar shield rating against EMI. In other words, you won’t yield the benefits of shielding unless both components are adequately protected.
2. There are two primary types of cable shielding from which to choose.
Though you will find variations of shielding, such as combination or spiral shielding, the two most common types are foil and braided. Both possess specific pros and cons that require careful consideration.
- Foil Shielding involves a thin copper or aluminum layer that encapsulates a cable or connector. This type of shielding is lightweight, offers 100% coverage against high-frequencies, and it is relatively inexpensive to produce. However, foil shielding is also extremely fragile, which limits its flex life and mechanical strength.
- Braided Shielding involves a tight criss-cross pattern of thin tin or copper wire that encapsulates a cable or connector. This type of shielding is strong, flexible and effective for all frequency levels (especially low frequencies). However, braided shielding does not guarantee full coverage and is on the bulkier side, which makes it more expensive to produce and ill-suited for tight spaces.
3. The effectiveness of a shielded cable will depend on three factors:
- The type and thickness of the shielding material.
- The presence of openings in the shield (e.g., small gaps in braiding).
- The effectiveness of the bonding connection to the ground.
Overlapping braided shielding with foil shielding can extend coverage and protection from external interference while properly grounded or “earthed” cables will decrease the cable’s radiated signal to enhance the effectiveness of shielding against EMI.
If you still aren’t sure whether or not you need a shielded cable connector, or you need help choosing the best shielding material for your application, iCONN Systems can help. Our engineers specialize in the design, development and manufacturing of cable assemblies for every type of environment imaginable, including those with high levels of EMI.
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