B.TECH - Semester 8 micorwave devices and circuits Question Paper 2013 (apr)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Write the equation of the characteristic impedance of a wire-over-ground transmission line.
- State the different band span of microwave frequencies.
- Define the directivity of directional coupler.
- What are the Properties of s-matrix?
- Give the properties of impedance $[z]$ and admittance $[y]$ matrix?
- What is the Key phenomenon taking place in TRAPATT diode?
- Define Gunn Effect.
- What are the assumptions for calculation of RF power in Reflex Klystron?
- State the impact of slow wave structures used in TWT amplifiers?
- Why phase focusing effect is important in magnetron? ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{2} \boldsymbol{=} \mathbf{2 0}$ Marks) P.T.O. Answer one full questions from each Module, 20 marks each.
- (a) Compare micro-strip and strip line from the perspective of sensitivity to the dielectric coefficient.
- (b) A lossless parallel strip line has a conducting strip width $w$. The substrate dielectric separating the two conducting strips has a elative dielectric constant of 6 and a thickness of 4 mm . Calculate the required width of the conducting strip i...
- (a) Discuss various aspects of coupling effects in transmission line configuration.
- (b) Explain how to calculate transmission power and power losses of rectangular wave guide.
- (a) What is directional coupler? Derive the S-matrix of two-hole directional coupler.
- (b) Derive the expression to find line impedance of transmission line.
- Derive the S-matrix for H-plane Tee and explain the operation of Magic plan tee. N-5754
- A microwave tunnel diode has a negative resonance resistance $R_{n}$ and a resonance circuit has a circuit resistance $R_{c}$. Derive an equation to calculate gain of a microwave tunnel diode amplifier.
- Derive the power gain, for frequency relations of Hetero junction Bipolar Transistors and explain the electronics applications of HBT.
- (a) Describe and derive Manley and Rowe Relations regarding power flow.
- (b) Derive the expression to find Transient Time for reflex klystron.
- (a) A reflex klystron operates under the following conditions $\mathrm{V} 0=600 \mathrm{v}$, $\mathrm{L}=1 \mathrm{~mm}, \mathrm{R}_{\mathrm{sh}}=15 \mathrm{~K} \Omega, \mathrm{e} / \mathrm{m}=1.759 \times 10^{11}\left(\mathrm{MKS}\right.$ system), $...
- (i) Find the value of reppeller voltage. (ii) Find the direct current necessary to give microwave gap voltage of 200 (iii) What is electronic efficiency under this condition?
- (b) Explain the operating principles of helix travelling wave tubes. ( $4 \times 20=80$ Marks)