Transmission Line in Steady State

The purpose of this applet is to demonstrate the forward, reverse, and total waveforms in a transmssion line in steady state. The demonstrated circuit consists of three parts, the source, the transmission line and load.

The source consists of the voltage supplied (at a certain frequency and phase angle) and an impedance with the following parameters:
Vs = source voltage,
phi = phase angle,
f = frequency,
Rs = real component of the source impedance (a resistance), and
Xs = imaginary component of the source impedance (a reactance).

The transmission line is described by the following parameters:
Ro = real part of the characteristic impedance,
Xo = imaginary part of the characteristic impedance,
alpha = real part of the propagation constant (the attenuation constant),
beta = imaginary part of the propagation constant (the phase constant), and
length = the transmission line length.

The load is an impedance with the following parameters:
RL = real part of the load impedance (a resistance), and
XL = imaginary part of the load impedance (reactance).

Use the scroll bars to set the parameters of the transmission line. You can adjust the speed of the animations with the animation delay values. When illuminated, the red warning light signifies that aliasing is occurring. This happens when the distance between samples exceeds half of the wavelength or when the sampling time (time interval, 1 sec) exceeds half of the drawing period. Note that values for X and phi are comprised of a mantissa in the range from 0 to 9.99 range and an exponent of base 10 in the range of -20 to 20.

For a good example, try the following steps:
  1. Click the example button in the applet.
  2. Set beta Exponent to 1.
  3. Set f Exponent to -2. This is the exponent of the frequency.
  4. Set alpha Mantissa to 0.01.
  5. Set alpha Exponent to 2.
  6. Set RL Exponent to 0.
  7. Set Animation Delay to 20.0 milliseconds by decreasing the exponent by 1; the exponent of the animation delay is the right slider.
This document was created in the fall of 1998 by William S. Brinson as part of his senior thesis titled Develop Java Applets to Assist in Education. The java programs belong to William S. Brinson and were not modified.
The HTML document was modified on September 18, 2001 by Brent Petersen.

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