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Lecture 9 of course 16.360 explores parameter equations, focusing on input impedance and the application of Smith charts in circuit analysis. Key concepts such as SWR (standing wave ratio), voltage maxima and minima, and impedance to admittance transformations are discussed. An example is provided where a 50-Ω lossless line terminated with a load impedance of (Z_L = 25 + j50 , Omega) is analyzed. The lecture further delves into the calculation of voltage reflection coefficients, SWR, and distances from voltage maxima and minima, enhancing comprehension of transmission line theory.
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16.360 Lecture 9 • Last lecture • Parameter equations • input impedance
16.360 Lecture 9 Parameter equations Unit circuit . Short Circuit load B Open Circuit load
16.360 Lecture 9 Parameter equations
16.360 Lecture 9 An example Smith Chart Input impedance Wavelength toward generator (WTG) Smith Chart
16.360 Lecture 9 An example find Zin (-0.1) Smith Chart Constant || circle, SWR Circle
16.360 Lecture 9 Today: • SWR, Voltage maxima and minima • Impedance to Admittance transformations
+ + |V(z)| |V(z)| |V0| [1+ | |], |V0| [1 - | |], = = max min 16.360 Lecture 9 SWR, voltage maximum and minimum If Smith Chart Recall: when 2z + r = 2n. when 2z + r = (2n+1).
16.360 Lecture 9 An example Smith Chart Impedance to Admittance transformations G: conductance, B, susceptance
16.360 Lecture 9 Normalized admittance z and y are directly opposite each other on Smith Chart
16.360 Lecture 9 An example A 50- lossless line is terminated in a load ZL = (25+j50). Use the smith chart to find a) voltage reflection coefficient, b) the voltage standing-wave ratio, c) the distances of the first voltage maximum and first voltage minimum from the load, d) the input impedance of the line, given the line is 3.3, and e) the input admittance of the line. Smith Chart
16.360 Lecture 9 Next lecture • Impedance matching