Читать книгу Handbook of Microwave Component Measurements - Joel P. Dunsmore - Страница 18

The techniques used for component measurements in the microware world change dramatically depending upon the attributes of the components; thus, the first step in describing the optimum measurement methods is understanding the expected behavior of the DUT. In describing the attributes and measurements of microwave components it is tempting to go back to first principles and derive all the underlying mathematics for each component and measurement described, but such an endeavor would require several volumes to complete. One could literally write a book on the all the attributes of almost any single component, so for this book the focus will be on only those final results useful for describing practical attributes of the components to be characterized, with quotes and references of many results without the underlying derivation.

There have been examples of books on microwave measurements that focus on the metrology kind of measurements (Collier and Skinner 2007) made in national laboratories such as the National Institute for Standards and Technology (NIST, USA) or the National Physical Laboratory (NPL, UK), but the methods used there don't transfer well or at all to the commercial market. For the most part, the focus of this book will be on practical measurement examples of components found in commercial and aerospace/defense industries. The measurements focus will be commercial characterization rather than the kinds of metrology found in standards labs.

Also, while there has been a great deal written about components in general or ideal terms, as well as much academic analysis of these idealized components, in practice these components contain significant parasitic effects that cause their behavior to differ dramatically from that described in many textbooks. Unfortunately, these effects are often not well understood, or difficult to consider in an analytic sense, and so are revealed only during an actual measurement of a physical devices. In this chapter, the idealized analysis of many components is described, but the descriptions are extended to some of the real‐world detriments that cause these components' behavior to vary from the expected analytical response.