ECE 5180  Midterm I (Transmission Lines)

 

Name _____________________________

 

You may use your portfolio and calculator.  No textbooks.


 

 

1.        (33 points) S/Z/Y Parameters

a.        Sketch the RLGC circuit for a transmission line.

b.       Find the Z-matrix using voltage and/or current dividers.  You can leave your answers in terms of impedance equations (something like Z1 || Z2 is acceptable).

c.        Find the ABCD parameters for the RLGC transmission line circuit. 

d.       Find the ABCD parameters for the RLGC matrix with the right port terminated in a 25 ohm load.  You can leave this in terms of matrix equations.


2.        (33 points) Double Stub matching networks

Design a double stub matching network to connect a load that is 75 + j 50 ohms to a 50 ohm line.  Use 50-ohm short-circuited stubs.  There is no distance between the load and first stub.  The distance between stubs is 0.04 wavelengths. Sketch your final design, labeling all lengths.


 

3.        (33 points) L matching

  1. Design an L-matching network to connect a load that is 75 ohms  to a 50 ohm line.  Use a high-pass design. 
  2. For a frequency of 1 GHz, specify the C and L values.
  3. The circuit shown below was designed to  match a load of 25 ohms to the generator.  Specify C and L components for proper matching when the load is 25 – j 10 ohms.  If you cannot absorb the load, describe in detail how to redo the problem using resonance (you do not need to do the actual calculations, but do specify each step).


 

 

ECE 5180 Midterm I

 

Name ___________________________

 

Problem 1 ________ / 33 points

 

Problem 2 ________ / 33 points

 

Problem 3 ________ / 33 points

 

                  + 1 point

 

Total         ________ / 100 points