Ryan Schrope
E-mag
Lab 2
1. Theoretical propagation delay:
2.
Figure 1: Actual propagation delay measured
3.
Figure 2: Propagation bounce with infinite load
Figure 3: Bounce for Open circuit
Figure 4: Bounce for load of 49.9 Ohms. There is almost no bounce since the load
approximately matches the line impedance.
Figure 5: Bounce for 22 Ohm load
Figure 6: Bounce for 100 Ohm load
4. Max/Min Plot for Open Circuit load
Figure 7: Max/Min plot showing standing wave pattern for Open Circuit
5. See Appendix A
6. Max/Min plot for Short Circuit Load
Figure 8: Max/Min plot for Short Circuit load
7. See Appendix A
8. Matlab Plot of Open and Short Circuit waves
9. **See Appendix A for Max/Min values
Figure 10: Standing wave for 100 Ohm load
Figure 11: Standing wave for 22 Ohm load
Figure 12: Standing wave for matched 49.9 Ohm load
Discussion Questions:
1. The difference in propagation delay is very minimal. Working in nanoseconds, even the
smallest error can be seen because of the small scale. In this case, it was most likely my
error in selecting the exact length of propagation on the graph.
2.
a) V1 has a small bounce while V2 has a much larger one. This matches the expected
results because the load is so mismatched there will be a ton of reflections
b) In this graph I can see 13 significant reflections.
c) There would seem to need to be more reflections if each took ~150 ns, but with the
small bounces I didn’t count it evens out.
d) V2 is undergoing a slight continuous bounce since it will never be matched here.
e) V1 is a constant input so it remains more steady, instead of oscillating
3.
a) Open circuit: For this V2 never bounces since it is open, but V1 has a slight initial bounce
b) 49.9 Ohm load: This has almost no bounce since the load is ~50 Ohms which matches
the load impedance
c) 22 Ohm load: Small bounce for V1 since the load is below out load impedance
d) 100 Ohm load: Small bounce but with V2, since our load is double the load impedance
4. The observed values somewhat match theoretical values, but are different because of
slightly altered resistance and timing from the DAD board
5. The amplitude will decrease the more times the transmission bounces losing amplitude
each time. Higher frequency operation will expedite this process.
6. The short circuit maxima are greater since the amplitude is higher. This means higher
frequencies on both the maxima and minima
7. Based on pre-lab calculations and the values I got, it seems to follow the frequency
trend for Lambda/4 values
8.
a) 22 Ohm load: The maxima frequencies are much greater while the minima are almost
the same
b) 49.9 Ohm load: The maxima frequencies are greater while the minima are the same
c) 100 Ohm load: The maxima frequencies are greater and the minima frequencies are a
bit less
Appendix A: