ELEC 401 MICROWAVE ELECTRONICS Lecture on Transient Analysis of TL Instructor: M. İrşadi Aksun Acknowledgements: Art work on most of the illustrations, and most examples have been taken from the following book: Elecrtromagnetics, by Branislav M. Notaros Pearson Int. Ed., 2010

Outline Chapter 1: Motivation & Introduction Chapter 2: Review of EM Wave Theory Chapter 3: Plane Electromagnetic Waves Chapter 4: Transmission Lines (TL) Chapter 5: Microwave Network Characterization Chapter 6: Smith Chart & Impedance Matching Chapter 7: Passive Microwave Components

Transmission Lines - Transient Analysis Step response of a lossless TL with a purely resistive load initial equivalent circuit as seen from the generator steady-state equivalent circuit

Transmission Lines - Transient Analysis Total voltage distribution, v(z, t), 0 ≤ z ≤ l, for RL, Rg > Z0

Transmission Lines - Transient Analysis Voltage waveforms at the generator Voltage waveforms at the load

Transmission Lines - Transient Analysis matched generator (Rg = Z0) unmatched load RL > Z0 RL < Z0

Transmission Lines - Transient Analysis Example: A 30 cm long lossless 50W coaxial cable, filled with a homogenous material of e=2.25 and m=1, is fed by a voltage generator of 5V at t=0, with the internal resistance of 75W, and is terminated by RL=25W . Sketch the voltage waveforms at both ends of the line. Voltage waveform at the generator Voltage waveform at the load

Transmission Lines - Transient Analysis Pulse Excitations

Transmission Lines - Transient Analysis Example: A lossless 50-ohm TL (length=45cm and e=4) is terminated by an ideal voltage generator of rectangular pulse with magnitude of 10V and duration of 2ns. At the other end, the line is terminated in a purely resistive load of 200-ohm. Sketch the voltage waveform at the load.

Transmission Lines - Transient Analysis Bounce Diagrams

Transmission Lines - Transient Analysis Example: A 30 cm long lossless 50W coaxial cable, filled with a homogenous material of e=2.25 and m=1, is fed by a voltage generator of 5V at t=0, with the internal resistance of 75W, and is terminated by RL=25W . Construct voltage and current bounce diagrams, and obtain the total voltage and current waveforms at z=7.5cm.

Transmission Lines - Transient Analysis

Transmission Lines - Transient Analysis