ECE 6130 MIDTERM I
February 18, 2000
Name _______________________________-
You may use your portfolio and a calculator.
1. (35 points) Design a double-stub matching network to match a load with ZL = 65 - j60 W to a 50 W line. The stub configuration is shown below (note that one stub is open, and the other is shorted!).
2. (30 points) Design an L-matching network to match a load with ZL = 40 + j 15 W to a 50 W line at 1 MHz. The circuit must pass 200 Hz waves. Do NOT design a circuit with an imaginary Q factor.
3. (35 points)
(a) Sketch the lumped element model of a transmission line.
(b) Find the complete (all four) S-parameters of this lumped element model (exact values are not given, so you can't use a Smith Chart).
(c) Show how to find the S-parameters of a long (several of the models from part a connected together) lossy transmission line USING the results from part b. (If you have complicated matrix multiplications, you do not have to do them.)
(d)
If three transmission lines are connected as shown below, describe in detail
how to measure their S12 using a 2-port network analyzer.
(e)
What (in terms of voltages and currents) does S12 represent?
ECE 6130 Midterm I
Problem 1 ________ / 35 point
Problem 2 ________/ 30 points
Problem 3 ________ / 35 points
Total _________ / 100 points