Keysight EDA has been in the RF and microwave design industry for decades. We asked How-Siang Yap, product manager for Keysight EDA’s RF and microwave software tools, to share his thoughts on RF design tips and techniques, and how designing boards at RF speeds compares with designing PCBs at slower speeds. As he explains, much of RF design involves battling interference and loss.
How does designing PCBs for wireless communications differ from designing a traditional PCB?
The major differences in designing PCBs for wireless communications are:
- Layout of traces, vias, interconnects, and packaging must consider the electromagnetic behavior of these physical structures on wireless communication performance.
- Layout must be optimized for RF (radio frequency) sensitivity to prevent interference and noise coupling from non-wireless and digital sections by shielding, absorption, or isolation.
- Layout must consider impedance matching between components and to antennas for optimal power transfer and low noise performance. This means that trace ground reference, shape, widths, and interconnecting transitions are not arbitrary, and they must obey RF signal propagation and radiation geometries.
- Select material properties of PCB board and layer stackup arrangements to ensure minimal loss of precious RF wireless signals to optimize performance.
What sort of problems do designers face in the RF arena that they don’t see with typical PCB designs?
Based on these differences, we can see that RF PCB design is not just designing interconnecting traces to fit onto a board. We must also consider how RF signals are protected from interference from non-RF sections on the same board and propagated along RF transmission lines such as co-planar waveguides (CPW) or microstrips with careful shaping of transitions and bends to prevent signal reflection and insertion loss.
To read this entire article, which appeared in the April 2023 issue of Design007 Magazine, click here.