The LTE-based M2M designs bring a new set of unique challenges that will make the choice of PCB material a prudent first step for a robust product design. First and foremost, LTE is synonymous with a sophisticated RF infrastructure, where the use of complex transmission technologies like OFDM and small cell networks make the selection of PCB material a key consideration.
When it comes to issues like board design and PCB material selection for M2M applications, there are a few things that won't change with the shift from 2G to 4G networks. For instance, M2M applications, mostly exposed to outdoor orindustrial environments, will continue to operate across a wide temperature range. Likewise, form factor, thermal requirements, and exposure to moisture and humidity will largely remain unchanged.
The use of technologies such as MIMO brings a heavy signal processing workload for M2M applications. Moreover, there are multiple wireless standards and handling the complexities of this multitude of wireless technologies can be a daunting task for an M2M board that is sometimes of the size of a credit card. The demand for faster processing and more efficient designs inevitably calls for thinner and more powerful PCBs.
In RF designs, for instance, the PCB material counts a lot when it comes to system parameters such as bandwidth and frequency of operation. Then, there are loss and uniformity requirements; a PCB contributes to system loss through conductor loss, dielectric loss and impedance mismatch. A high-frequency signal on the PCB is severely affected by the dielectric loss.
The M2M and other IoT applications are still evolving and so is the PCB market of these applications. Isola Group is one such outfit that has kept an eye on the evolving needs of PCB fabricators for M2M and other emerging IoT devices. The company recently made available the IS350MD laminate material that has been engineered specifically for ultrathin dielectric applications.