![smith chart matching smith chart matching](https://i.ytimg.com/vi/TsXd6GktlYQ/maxresdefault.jpg)
The goal is to intersect the Re=1 constant resistance circle so that With a parallel capacitor, we will move along the Note that z_A can be rewritten as y_A = 0.25 - i*0.25. Inductor to move the impedance to intersect the Re=1 circle. In fact, we have two options here: we can use a parallel capacitor or a parallel Which is no big deal, since we can simply use a parallel component to move the impedance to intersect the Re=1Ĭircle. Impedance to intersect the Re=1 or the Re=1 circles, we find we can't do it.
#Smith chart matching series
However, if we try to use a series component to move the In the previous example we did matching with a seriesĬomponent followed by a parallel component. Let's take a look at the impedance z_A = 2 + i*2. Page this was done with a series inductor and a parallel capacitor. Hence, we have performed impedance matching using a series capacitor and a parallel inductor on the previous The impedance matching network for Example 1. This impedance matching network is shown in Figure 3:įigure 3. A parallel inductor cancels out the susceptance. That is, if we addĪ parallel inductor with a susceptance of -i*3, the impedance will be translated to the center of theįigure 2. To complete the impedance matching, we just need to cancel out the susceptance. Using a Series Capacitor to Move zA to the Re=1 circle. This is illustrated in Figure 1:įigure 1. Will be transformed to z1=0.1-i*0.3, which is equivalent to y1=1+i*3. Using a capacitor with a series reactance of -i*0.1, the impedance By observing the immittance Smith Chart, we could also accomplish this withĪ series capacitor. Recall that we moved the impedance z_A to intersect the Re=1 circle with a series What alternatives do we have to match this impedance? Matched an antenna with impedance z_A=0.1-i*0.2 with a series inductor and a parallelĬapacitor. In Example 1 on the immittance Smith Chart page, we Impedance matching examples to illustrate the usefulness of the immittance Smith Chart. On the previous page, the immittance Smith Chart was introduced. The examples provided here are solved using graphical tools and a printed Smith chart, rather than the computer program, to emphasize the techniques and approximations involved although some of the numerical results listed were obtained with a computerized Smith chart ( smith-chart.m) available with this text ( see page xi).Include Form Remove Scripts Accept Cookies Show Images Show Referer Rotate13 Base64 Strip Meta Strip Title Session Cookies Immittance Charts: More Impedance Matching Previous: Immittance Smith Chart A computerized Smith chart can then be used to analyze conditions on lines. Naturally, any chart can also be implemented in a computer program, and the Smith chart has, but we must first understand how it works before we can use it either on paper or on the screen. Some measuring instruments such as network analyzers actually use a Smith chart to display conditions on lines and networks. Although the Smith chart is rather old, it is a common design tool in electromagnetics. As such, it allows calculations of all parameters related to transmission lines as well as impedances in open space, circuits, and the like.
![smith chart matching smith chart matching](https://www.dxzone.com/dx34236/interactive-smith-chart.jpg)
The Smith chart is a chart of normalized impedances (or admittances) in the reflection coefficient plane. This has been accomplished in a rather general tool called the Smith chart. Thus, the following proposition: Build a graphical chart (or an equivalent computer program) capable of representing the reflection coefficient as well as load impedances in some general fashion and you have a simple method of designing transmission line circuits without the need to perform rather tedious calculations.
![smith chart matching smith chart matching](http://www.engineering-electronics.com/assets/images/autogen/smithskpk-xyz.jpg)
You may also recall, perhaps with some fondness, the complicated calculations which required, in addition to the use of complex variables, the use of trigonometric and hyperbolic functions. The reflection coefficient, in turn, was defined in terms of the load and line impedances (or any equivalent load impedances such as at a discontinuity). Voltage, current, and power were all related to the reflection coefficient. The reflection coefficient was used to find the conditions on the line, to calculate the line impedance, and to calculate the standing wave ratio. A look back at much of what we did with transmission lines reveals that perhaps the dominant feature in all our calculations is the use of the reflection coefficient.