problem 1: With the help of a smith chart, compute the position and length of a short-circuited stub matching a (180 + j120) ohm load to a 300 ohm transmission line. Supposing that the load impedance remains constant, determine the SWR on the mainline when the frequency is (a) raised by 10% (b) doubled.

problem 2: What do you mean by Directional coupler? Illustrate the construction of 2-hole directional coupler.

problem 3: The input power in a two hole directional coupler is 1mW. The coupler consists of a coupling factor of 15 db and a directivity of 30 db. Compute the power in all the ports.

problem 4: A symmetric directional coupler with infinite directivity and a forward attenuation of the 20db is employed to monitor the power delivered to a load. Bolometer 1 introduces a VSWR of 2on arm 4and bolometer 2 is matched to arm3. If bolometer1 reads 8mwand bolometer2 reads 2mW, determine:

a) The amount of power dissipated in ZL
b) VSWR on arm2.

problem 5: List all the properties of ferrites which make them helpful in the construction of isolator’s and circulators.

problem 6: Why TEM waves can’t be propagated in the wave-guides?

problem 7: Why rectangular waveguides are favored over the circular waveguides in some applications?

problem 8: What do you mean by magic Tee and describe why E-H plane is named as the magic Tee?

problem 9: Compute the ratio of crossection of circular waveguide to that of a rectangular one if each is to have similar cutoff wavelength for its dominant mode.

problem 10: Describe the behavior of ferrites in the isolators and circulators.