ECE 6180� Midterm I (Transmission Lines)����� Feb. 15, 2002

Name _____________________________

You may use your portfolio and calculator.� No textbooks.

1. (33 points) Double Stub matching networks

Design a double stub matching network to connect a load that is 10-j15 ohms to a 50 ohm line.� Use 50-ohm short-circuited parallel stubs.� The distance between the load and first stub is 0.1wavelengths.� The length of 50-ohm line between the stubs is 0.125 wavelengths.� Sketch your final design, labeling all lengths.

2. (33 points) L matching

1. Design an L-matching network to connect a load that is 200 ohms� to a 50 ohm line.� Use a high-pass design.�
2. For a frequency of 1 GHz, specify the C and L values.� Sketch your final network.
3. Sketch a circuit to match a load that is 200 + j 100 ohms.�� (You may use either resonance or absorption, whichever is easier.)

3. (33 points) S Parameters

Specify the S-matrix for an LC filter in series with a quarter-wave transformer as shown.� You may use any method.� It is not necessary to compute the values of the S-matrix, but show how to do all necessary computations.�

ECE 6180 Midterm I

Name ___________________________

Problem 1 ________ / 33 points

Problem 2 ________ / 33 points

Problem 3 ________ / 33 points

��������������� � + 1 point

Total�������� ________ / 100 points