1. The length of a microstrip trace line connecting two components on a chip is 50 cm. A sinusoidal signal of frequency 1 GHz is supplied to the trace at one end. Assuming the velocity of propagation of the signal is 2e8 m/s,

a) Calculate the time taken by the signal to reach the other end of the trace.

b) What is the phase difference between the signal at the two ends of the trace?

2. The transmission line parameters of a line are

R = 0.2Ω / m,L = 0.3µH / m,G = 0 / m,C = 15pF / m. At an operating frequency of 1 GHz,

a) What is the propagation constant of the transmis-sion line?

b) Calculate the characteristic impedance of the transmission line.

3. A RG-59U coaxial cable has a loss of 10 dB per 100 ft of length. A 10 V-3A signal is generated us-ing a function generator and connected to one end of the 50 ft long cable. On the other side, the cable is impedance matched to a set top box unit.

a) Find the power delivered to the load.

4. A transmission line with characteristic impedance

Z0 = 50 − j5Ω and propagation constant

γ = 0.2 + j2.5 / m is connected to a load imped-

ance of 100 + j50Ω .

a) Reflection coefficient of the line at the load end =

b) Reflection coefficient of the line 5m from the load =

5. On a 50Ω BNC cable line, the reflection coeffi-

cient is measured at the load end to be 0.7∠30 .

If the propagation constant of the line is

20∠89 / m ,

a) The impedance seen on the transmission line at a distance of 4m from the load =

6. A 300Ω transmission line is connected to a circuit

with an input impedance of 75 + j35Ω .

a) Find the VSWR of the line

b) Maximum impedance seen on the line =

c) Minimum impedance seen on the line =

7. You are required to design a system that will de-tect broken transmission lines. The transmission lines run underwater over distances of 5000 km. It is very expensive to go along the transmission line looking for the exact region that is broken. The requirements are that your system should be able to predict the position of the breakage of the line, so that service personnel can be sent to that exact location to fix it.

a) What would be the background technical idea on which you would design such a system?

b) What kind of a source would you choose ? Would you choose a square waveform or a sinusoidal waveform or a Gaussian waveform or an impulse function or a series of impulses? Why ?

c) List the components you would need to create such a system and report the approximate cost.

d) What name would you give to your system? Is there a name already given by the community to these kinds of devices?

e) Did you know that at IIT Madras, such a device was developed on the same principles and was actually commercialized very recently? Find the name of the company that bought the technology from IIT Madras to use it.

Tutorial 2 page 1 of 1

Spring 2013EC 2204