detailed operation of a VNA is described in Chapter 2.
Extensions to traditional VNAs allow them to create multiple signals for two‐tone measurements and to have very low noise figures for noise figure measurements. But the main attraction of VNAs is calibration. A key attribute is that since they measure the magnitude and phase of waves applied to their ports, they can use mathematical correction to remove the effects of their own impedance mismatch and frequency response in a manner that makes their measurements nearly ideal. The details of VNA calibration are covered in depth in Chapter 3.
Thus, even though there is a wide variety of test equipment available for microwave component measurement, by far the most widely used is the VNA, and while many of the topics of component measurements in this book are extensible to any of the previous instruments, the specific implementation and examples will be illustrated primarily using the VNA, as that has become the predominant component test analyzer in use today.
References
1 Cameron, R.J., Kudsia, C.M., and Mansour, R.R. Microwave Filters for Communication Systems: Fundamentals, Design, and Applications. Hoboken, NJ: Wiley‐Interscience. Print.
2 Cohn, S.B. (1954). Characteristic impedance of the shielded‐strip transmission line. Transactions of the IRE Professional Group on Microwave Theory and Techniques 2 (2): 52–57.
3 Collier, R.J. and Skinner, A.D. (2007). Microwave Measurements. London: Institution of Engineering and Technology. Print.
4 Collin, R. (1966). Foundations for Microwave Engineering. New York: McGraw‐Hill. Print.
5 Dunsmore, J. (1988). Utilize an ANA to model lumped circuit elements. Microwaves and RF: 11.
6 Freiberger, K., Enzinger, H., and Vogel, C. (2017). A noise power ratio measurement method for accurate estimation of the error vector magnitude. IEEE Transactions on Microwave Theory and Techniques 65 (5): 1632–1645.
7 Hong, J.‐S. and Lancaster, M.J. (2001). Microstrip Filters for RF/Microwave Applications. New York: Wiley. Print.
8 Hunter, I.C. (2001). Theory and Design of Microwave Filters. London: Institution of Electrical Engineers. Print.
9 IPC (2004). IPC‐2141A: Design Guide for High‐Speed Controlled Impedance Circuit Boards. Northbrook, IL: IPC Print.
10 Keysight Technologies. (1968). HP Application Note AN‐95‐1 [Online]. Available at: http://literature.cdn.keysight.com/litweb/pdf/5952-0918.pdf (Accessed 20 January 2020).
11 Kurokawa, K. (1965). Power waves and the scattering matrix. IEEE Transactions on Microwave Theory and Techniques 13 (2): 194–202.
12 Magnusson, P. (2001). Transmission Lines and Wave Propagation. Boca Raton, FL: CRC Press. Print.
13 Marks, R.B. and Williams, D.F. (1992). A general waveguide circuit theory. Journal of Research of the National Institute of Standards and Technology 97 (5): 535–562.
14 Mini‐Circuits. (n.d.) Amplifier Terms Defined AN‐60‐038 [Online]. Available at: http://www.minicircuits.com/app/AN60-038.pdf. (Accessed 11 Feb. 2012).
15 Pozar, D.M. (1990). Microwave Engineering. Reading, MA: Addison‐Wesley. Print.
16 Simons, R.N. (2001). Coplanar Waveguide Circuits Components and Systems. Wiley. Print.
17 Sombrin, Jacques, 2011. On the formal identity of EVM and NPR measurement methods: Conditions for identity of error vector magnitude and noise power ratio, Microwave Conference (EuMC), 2011 41st European, IEEE, 337–340.
18 Wen, C.P. (1969). Coplanar waveguide: a surface strip transmission line suitable for nonreciprocal gyromagnetic device applications. IEEE Transactions on Microwave Theory and Techniques 17 (12): 1087–1090.
19 Williams, D.F., Ndagijimana, F., Remley, K.A. et al. (2005). Scattering‐parameter models and representations for microwave mixers. IEEE Transactions on Microwave Theory and Techniques 53 (1): 314–321.
20 Zverev, A.I. (1967). Handbook of Filter Synthesis. New York: Wiley. Print.
Note
1 1 Lord Kelvin, “On Measurement.”
2 VNA Measurement Systems
2.1 Introduction
S‐parameter measurements of devices provide the common reference for RF and microwave circuit and system analysis. While the basic methods of S‐parameter measurements were developed decades ago, many advances have occurred in just the last five years that makes obsolete the common understanding of the capabilities and limitations of these measurements. Vastly improved hardware and software capabilities provide for control of stimulus signals and analysis of response signals that allow measurement systems to extend the basic linear S‐parameters to multiport, differential, and non‐linear characteristics. In the past, S‐parameters were limited to two ports; now up to 32‐port systems are readily available. In the past, measurements were limited to linear responses; now non‐linear, distortion, noise, and even load pull characterizations are possible. In the past, calibration techniques were restricted to a few limited sets of standards and algorithms and limited to devices with the same input and output frequencies; now a wide range of calibration algorithms and applications can be applied to a variety of components, with few restrictions.
A clear understanding of the underlying architecture of a vector network analyzer (VNA) is necessary to understand the full capabilities and limitations of the modern VNA. The first part of this chapter deconstructs the VNA to discuss the individual block diagram elements, their attributes and deficiencies, and how they operate together to provide the capability and applications described in later chapters. In the history of VNAs, the HP 8753 and the HP 8510 were the industry‐leading RF and microwave VNAs of the 1980s and 1990s, from which many of the principal understandings of capabilities and limitations were formed. For that reason, many of the characteristics of these analyzers are discussed in the following sections to provide a context for the discussion of the modern VNA attributes. In almost all cases, many well‐known limitations of these products no longer apply, and a key goal of the first section of this chapter is to illuminate to the reader these improvements.
By around the year 2000, an arms race of sorts emerged in the world of VNAs with the nearly simultaneous introduction of the PNA and ENA families from Agilent, the Ballmann S100, the ZVR and ZVK from Rohde‐Schwartz, the Lightning™ and Scorpion™ from Anritsu, and the 3765 from Advantest. By 2010, Agilent and Rohde‐Schwartz advanced to the modern generation of multi‐function component test platforms, the PNA‐X and the ZVA, while Anristu's products remained mostly in the area of linear S‐parameter test in the form of the Vectorstar™. As the author is a principle designer and architect of the Keysight products, the details on the VNA architecture, structure, and capabilities described here are derived from this knowledge. But many of the factors discussed apply equally well to all measurement systems, regardless of manufacturer, including custom‐built systems sometimes seen in university research labs or national standards laboratories. Because of these advancements,
