Q1 .  a) Draw the diagram of two-cavity klystron amplifier and explain its working. \n b) Explain about limitations of conventional tubes at microwave frequencies.

Q2 .  a) What is S-matrix? Explain its significance and write the properties of S-matrix. \n b) Explain the operation of circulator and write its applications.

Q3 .  a) Derive the field equations of rectangular waveguide in TM mode, starting from Maxwell’s equations. \n b) Calculate the guide wavelength (in cm) at 7 and 12GHz for an air filled waveguide with a=2.54 cm , b=1.5cm .

Q4 .  a) What are the different types of attenuators? Explain them with neat diagrams \n b) Derive S-matrix of Magic Tree and also draw its structure.

Q5 .  a) Explain the bunching process of two cavity klystron and how to convert velocity modulation into current modulation and also derive the equation for efficiency? \n b) How to change the frequency of oscillations in reflex klystron?

Q6 .  a) What are the different propagation constants TWT? How to calculate them? \n b) What is Hartree condition in Magnetron? Derive the equation for Hartree voltage of it.

Q7 .  a) Draw the characteristics of Gunndiode and explain how negative region is obtained in it? \n b) What is bolometer? How it is used for microwave measurements?

Q8 .  a) Derive the field equations of rectangular waveguide in TE mode, starting from Maxwell’s equations. \n b) Prove that the cutoff frequency is same for both TE and TM modes.

Q9 .  a) Derive the equation of optimum output power of two cavity Klystron amplifier. \n b) Draw and explain the mode characteristics of Reflex Klystron.

Q10 .  a) Explain how Gunn diode is used as an oscillator? Explain with the help of circuit diagram. \n b) Explain the method of measurement of low and high VSWR with neat diagrams.

Q11 .  a) Why the TEM wave is not possible in rectangular waveguide? b) A rectangular waveguide has the following characteristics: b=1.5cm, a=3.0cm, µg = 1, and εg=2.25 Calculate cutoff wavelength, frequency, λg, Zo and attenuation constant at 3.0 GH

Q12 .  a) What are the different types of Directional couplers? Explain the working of two hole directional coupler. \n b) Derive the S-matrix of E plane Tee and also write its characteristics

Q13 .  a) Explain the bunching process of reflex klystron and also derive the equation for efficiency? \n b) Why multi cavities are used in Klystron amplifiers?

Q14 .  a) Explain the principle of working of IMPATT diode with suitable structure and characteristics. \n b) What are the different precautions have to be made while measuring parameters at Microwave range?

Q15 .  a) Calculate the cutoff frequencies of air-filled wave guide with a=3.24cm and b=2.2cm, for the TE10, TE20, TE01, and TM11 modes. \n b) Determine the power loss in rectangular waveguide.

Q16 .  a) Explain the bunching process in two cavity klystron amplifier with Apple gate diagram. \n b) Explain how oscillations are generated in reflex klystron? How to calculate its electronic admittance?

Q17 .  a) Explain the principle of working of TRAPATT diode with suitable characteristics. \n b) Explain the method of measurement of impedance at microwave frequencies with suitable block diagram.

Q18 .  a) Explain the operation of magic tee with neat diagram and derive it's S- matrix? \n b) Explain in detail about waveguide irises, tuning screws and posts, waveguide attenuators with neat diagram?

Q19 .  a) Explain different types of directional couplers with neat sketches and derive the S- matrix for directional coupler? \n b) Explain the operation of Four-port circulator with suitable diagrams?