Any electronic device or system comprises PCBs, interconnects, cables, and more. Interconnects often work as antennas, especially in high-frequency applications, where noise or EMI may be an issue. EMI mitigation and PCB design play a crucial role in the overall, efficient functioning of the device. Antennas work as signal sensing, transmitting, and receiving devices that can be either externally positioned or inbuilt in most electronic sensing devices such as smartphones, smart lighting systems, and many more. However, antennas can be the source of electromagnetic interference (EMI) which may affect even board level components. Optimizing antenna design in the right way can help prevent EMI signals from reaching the circuit board. This post discusses antenna designs in PCBs and their significance in EMI shielding at board level.
PCB Antenna Design Guidelines to Prevent EMI
Here are some pointers for antenna design and positioning in a printed circuit board with regards to EMI mitigation and overall device or system functioning.
- The placement of interconnect or antenna is crucial as it must be kept away from analog circuits, sensitive components mounted on the board, and more.
- Set the signal emission pattern for the antenna via a solid ground plane so that signals transmitted or received do not scatter and clash with other signals from components.
- Appropriate grounding methods help contain EMI. Connect the antenna to a common ground point to prevent unwanted noise.
- Use RF or EMI shields to keep the antenna area on the PCB separate and isolated. This prevents EMI coupling.
- Ensure impedance matching and control are achieved with regards to appropriate placement of vias, trace lengths, short signal routes, and more.
- Perform tests for EMI and EMC compliance. Also, it is highly important to measure radiation emitted from a system or equipment.
- Ensure your PCB design is perfect, and use tools such as DFM and standard design software. This way EMI suppression can be catered to at design level.
- Use flexible thin plasticized metal EMI shields for the boards. You can get them customized to suit the exact dimensions and shape of the board. Ensure they are removable in case you need to add or remove components on the board.
While PCB design as well as the placement and type of interconnects and antennas play a huge role in EMI management, it is important to consider flexible board level shielding. There are many shielding solutions available for PCBs; however, it is best to choose lightweight and bendable shields which can be easily stuck on and removed if required. They must offer complete suppression or filtration of electromagnetic or radio frequency waves. XGR Technologies offers SnapShot® EMI shields that not only meet the US EMC standards but offer complete protection from EMI and RFI. They are made from a thin polyetherimide film on the inner side and conductive tin on the exterior surface. These are lightweight and flexible EMI shields that help reduce electromagnetic coupling. If you need further information on these EMI shields, you can contact the XGR Technologies team via phone or email.
