Understanding the “Black Art” of RF and Microwave Switching

Understanding RF, especially microwave switching, can be a challenge. In many cases, test systems have been compromised because a test engineer did not consider all the components of their test system: instruments, switching, cabling, Mass Interconnect (test fixture interface), fixture design, and so on. Each component has its own set of characteristics. With RF and microwave components, effects including insertion loss, VSWR, bandwidth, and so on all need to be considered as well.

Higher bandwidth is a constant demand. The most obvious current example is the emergence of 5G systems that will be hitting the market in the near future, but there are many defense systems - often with their own protocols - that are now operating at RF and high-frequency bandwidths. In short, the need to employ repeatable, accurate RF and microwave switching systems is only going to increase, and while this may appear to be a “sexy” subject, without a proper appreciation of the challenges involved, test systems designers could find themselves facing a lengthy process involving a great many iterations while inconsistencies and failures are ironed out.