The normal variation of several processes within circuit fabrication, can have multiple influences on RF performance. For some situations, the RF influence due to a process having normal variation can be significant at lower frequencies and less influential at higher frequencies. However, it is more common for the higher frequency applications to be more influenced by the PCB fabrication process. When considering the RF consistency of a circuit design, understanding the potential PCB fabrication influences in relation to frequency, can be important considerations for the designer.
This presentation will start with a basic overview of insertion loss and phase response. The material and circuit properties that influence insertion loss and phase will be given, along with frequency dependencies. Multiple circuit fabrication processes will be discussed, and examples given for their influence on RF performance at different frequency bands. There will be comparisons of RF performance, due to circuit processing influences, at sub 6 GHz, Ku band (12 to 18 GHz), 24 GHz, Ka band (26.5 to 40 GHz), 60 GHz, 77 GHz and 94 GHz.