It is named after Phillip Smith, who created it while at Bell Labs in the early 1930’s. The Smith chart is a graphical tool for determination of the reflection coefficient and impedance along a transmission line. And we all know that impedance is termed as the sum of reactance and resistance and in the same way, the reflection coefficient is also a complex numeral and so represented as load impedance ‘ZL’ and the reference impedance ‘Z0’. The complex reflection coefficient is generally simply referred to as reflection coefficient. If we were to leave these values of S11 for constant real and imaginary components on the polar plot curves, we could use them as reference grid lines to read impedance right off the plot. As it was already stated that Smith chart exhibits intricate reflection coefficients in the polar form for specific load impedance. Come back here if there’s anything you’d like clarified. The normalized input impedance for that transmission line is read from the Smith Chart to be 1 - j0.75. This represents the length of the transmission line, where is the wavelength in the transmission line.
Compute the required circuit Q by (1 + Q2) m, or 3 L I F1. This equation shows that, for a standing wave, the complex reflection coefficient and impedance repeats every half wavelength along the transmission line. Answer: There is an excellent description of the Smith Chart on Wikipedia, so I’d refer you to that in the first instance. Smith Chart Example The distance moved on the scale is 0.348 - 0.198 0.15. This Lecture: Smith Chart and S-Parameters Quick notes about matching networks Smith Chart basics Scattering Parameters EE142-Fall 2010 4 Matching Network Design 1. The Smith chart can be used to simultaneously display multiple parameters including impedances, admittances, reflection coefficients, S n n Use of the Smith chart utility has grown steadily over the years and it is still widely used today, not only as a problem solving aid, but as a graphical demonstrator of how many RF parameters behave at one or more frequencies, an alternative to using tabular information. Smith (1905–1987), is a graphical aid or nomogram designed for electrical and electronics engineers specializing in radio frequency (RF) engineering to assist in solving problems with transmission lines and matching circuits.