Issue link: https://iconnect007.uberflip.com/i/1062752
82 DESIGN007 MAGAZINE I DECEMBER 2018 reduce the noise given off by the edges of the board. Edge noise was a significant issue with buried capacitance. We started working with it and developing some IP to give us a history in the field, and also to serve as a vehicle for further study. Next, we created some samples. We went through testing in Silicon Valley at Dr. Earl McCune's laboratory. We did a lot of analysis with Dr. McCune. From that, we derived and sent the samples that gave us the very most interesting results to an FCC testing laboratory with a set of engineers at that end to help us interpret the responses. The responses were as we expected in terms of reducing the noise from the PCB for virtually no cost or no cost that we could think of. We reduced the edge noise and avoided potential fixes like edge plating, etc., that would have to be done on a board. We also dis- covered something else that was a little harder to explain, and we didn't notice it in our first analysis. However, a group of engineers from a company—and we can't use the name because we never made it public that we talked with these folks—said, "This is absolutely astonish- ing." What happens to the point at which this becomes resonant is it simply moves, not a little, but five, six, or seven GHz and up the range. One GHz doesn't sound like much to us when we're talking about 10 or 15 meters, but a GHz covered the entire FCC range that was talked about for all of the years since elec- tronics has existed; it's an enormous range of change. In doing that, we finally came upon what we think is the right bit of information that everybody needs to know to determine whether this is something that might be of help to them in terms of developing their tech- nologies. This is potentially a method of, at virtually no cost, increasing the ability of the board to operate at higher frequencies, and, at the same time, reducing the edge noise that's radiated by the same board. I felt that there was an interest within the 5G community for a solu- tion to the problem of really high-speed traffic over standard PCBs. The research and devel- opment groups of material laminators simply made a statement that above three to six GHz, the typical materials used by the PCB industry will not operate or give them any results that they can use. Looking at that, I'd have to say that's a pretty accurate analysis. We've done our own analysis on that. When you add in special materials— the PTFE group and some of the hybrids and other special materials created by the indus- try for these purposes—you can increase the speeds of surface signals and do other things in that regard. However, you really can't do anything about the electrical energy necessary to operate the devices and act as a ground for those high-speed signals on the system. So, when looking at the integration of this with a high-speed PCB, we arrived at three basic ideas. One, if you wish to obtain very high-speed operation on a PCB, you may wish to include optical systems within that PCB, at least to accomplish theoretical objectives, but at a very large cost. Or you can use special materials to create all of the desired Dk and Df objectives at a significant cost. However, frac- tals give a third option. You can not only use regular PCB materials to create higher-speed boards, but you can also add it to the special materials available to create an even higher- speed board that may allow the production of the kinds of PCBs that they would need to fully carry out their mission in terms of high-speed latency networks like 5G. Now, this is not to paint a panacea. We're not in the position of saying all the research has been done and that we know precisely The responses were as we expected in terms of reducing the noise from the PCB for virtually no cost or no cost that we could think of.