Almost everyone in the electronics business is familiar with the FCC’s Part 15 regulations your circuitry cannot interfere with the operation of other products. And everything from LED lightbulbs and battery-powered toys to super-fast computers must comply with the FCC’s radiated emission regulations, measured about 10 feet away from the product (exactly 3 meters…). Because every device that has electronic circuitry inside generates radiated emissions that can interfere with nearby cellphones, computers, and televisions.
Is meeting the FCC limits enough for your product?
Not if part of your product is a radio module, like WiFi or Bluetooth or a cellular transceiver. Now the concern is not 10 feet away, or even 10 inches away the radio module that is trying to listen to a tower a mile away is inside your product, only inches away from the computer circuitry and power supply! It’s like that annoying person next to you talking in a movie theater while you are trying to hear the quiet dialogue, or somebody running the vacuum cleaner during your favorite show…NOT GOOD! The range and performance of your radio module can be destroyed by nearby circuitry that is well within the FCC’s allowed radiated emission limits.
Or what if your product has ultra-sensitive circuits for audio, video, or measuring sensors? The performance of your product can be limited by nearby noisy circuits.
In these situations, special care is needed for the non-radio circuit design and especially the pcb layout. Additional filters may be needed, inductors need to be carefully positioned, power and ground traces are critical. Shielding may even be needed to separate the super-sensitive circuits from the noisy ones.
MSRK Design specializes in developing products that contain RF (Radio Frequency) circuits and require extra care to combat noisy circuits. Nearly every product we’ve developed over the past 2 decades has either a sensitive radio inside, or large sources of EMI (like Ethernet), or both. We are available to help design your product, review your existing design, or fix your EMI problems.