Southwest Microwave conducted this study in hopes that it would help board designers to better understand transmission and launch structures. When Southwest Microwave introduced their end launch connectors, it meant that the user was no longer responsible for packaging and would now only be responsible for laying out the board design. To make sure that users could implement the connectors in the most effective way for their applications, Southwest Microwave conducted this study to explore the relationship between board layout design and actual microwave performance.
In this study, Southwest Microwave examined grounded coplanar waveguide (GCPWG) launches and both top ground launches to microstrip lines and microstrip lines that run straight up to the edge of the board and found that there were significant differences in performance between the three different configurations. In board layouts with the microstrip running straight to the edge there was more radiated loss than the others, though that loss was considered “reasonable” when used at lower frequencies. Comparatively, the top-ground launch microstrip configuration had less radiated loss. Overall, the GCPWG configuration had the least radiated loss though it presented more line loss.
Southwest Microwaves concludes that the application is the main determination of which configuration would be best. If you’re using longer lines and loss is the main concern, then one of the microstrip options would be the better choice. If, however, you’re using very short lines or are simply more concerned with isolation and bandwidth than with loss, then GCPWG is a more effective option.
For the full details of the study, including in-depth data analysis, board layout diagrams and more detailed explanations of the findings, read the whole PDF. It’s provided here for your convenience by HASCO, Inc., the premier distributor of RF cable assemblies, Southwest Microwave connectors and other Southwest Microwave products.
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