The principle of the antenna effect, as described by the laws of
electromagnetism, is based on the ability of conductors to interact with
electromagnetic fields and radiate or receive electromagnetic energy.
Understanding this principle is the first step in devising effective methods to
eliminate or mitigate the antenna effect in electronic systems.
One of the primary approaches to eliminating the antenna effect is proper
design and layout. In integrated circuits, minimizing the length of metal
interconnects and avoiding long, unbroken traces can reduce the likelihood of
these structures acting as antennas. Using shielded or grounded vias to connect
different metal layers can also help contain the electromagnetic fields and
prevent radiation. In PCBs, carefully routing traces to avoid creating resonant
lengths, maintaining proper impedance matching, and using controlled impedance
transmission lines can significantly reduce the antenna effect.
Shielding is another effective technique. By enclosing conductors or
components in a conductive shield, such as a metal enclosure or a shielded
cable, the electromagnetic fields can be confined, preventing them from
radiating out or coupling in external interference. The shield should be
properly grounded to ensure its effectiveness. Ferrite beads and chokes can also
be used to suppress high-frequency noise and reduce the antenna-like behavior of
cables. These components act as high-pass filters, attenuating unwanted
high-frequency signals while allowing low-frequency signals to pass through.
Filtering circuits are also commonly employed to eliminate the antenna
effect. Low-pass filters can be added to the input and output of electronic
circuits to remove high-frequency noise that may cause electromagnetic
radiation. Common-mode filters, which target common-mode interference (noise
that appears on both conductors of a differential pair), are particularly useful
in reducing the antenna effect in data and power cables. Additionally, proper
grounding and decoupling techniques, such as using bypass capacitors and
ensuring a low-impedance ground plane, can help minimize the electromagnetic
fields generated by the circuit and reduce the antenna effect.
Home >
+86 186 8871 1070
