Antenna and Wave Propagation 2018 Question Paper — Government College…
The 2018 Antenna and Wave Propagation previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Antenna and Wave Propagation
- Course: ANTENNA & WAVE PROPAGATION
- Branch: Electronics & Communication Engg.
- Year: 2018
- Paper: end-term
- Duration: 180 minutes
- Total marks: 100
Instructions
- Attempt five questions in all, selecting at least two questions from each section.
Questions
SECTION-A
- Q1. (a) Differentiate between: (i) Isotropic and Omnidirectional Antenna (ii) Fraunhofer and Freznel Zone (iii) Antenna Gain and beam Directivity (iv) Antenna Bandwidth and Beamwidth (b) Find the relation between Directivity and Effective Aperture. [20 marks]
- Q2. (a) Find the directivity, efficiency and effective area of an antenna if its $R_r$ is $80\,\Omega$ and $R_L$ is $10\,\Omega$. The Power gain is $10\text{dB}$ and operating at frequency of $100\text{ MHz}$. (b) Using reciprocity theorem prove that for antenna being used as transmitting or receiving element effective length remains the same. [20 marks]
- Q3. Find the fields of thin linear antenna in far field. Sketch the radiation pattern of half wave dipole and full wave dipole. [20 marks]
- Q4. (a) Explain the following: (i) Uniform array (ii) Broadside Array (iii) Endfire Array (iv) Phased scanning array (b) Find the array factor of uniform array of N isotropic point sources. [20 marks]
SECTION-B
- Q5. (a) Explain the principle and construction of a Yagi-Uda antenna. What are its typical applications? (b) What is a parabolic reflector antenna? What are its advantages and limitations? [20 marks]
- Q6. (a) Explain the difference between ground waves and sky waves in the context of radio wave propagation. (b) What is the effect of Earth's magnetic field on sky wave propagation? [20 marks]
- Q7. (a) Derive the Friss Transmission formula for free space propagation. (b) What is maximum distance that can be covered by space wave communication if transmitting and receiving antenna heights are 300 feet and 100 feet respectively? (c) Explain duct propagation. [20 marks]
- Q8. (a) How are radio waves bent by ionosphere. Why frequencies above 30 MHz are not bent? (b) Determine the electron density of a layer if critical frequency is 2.0 MHz. [20 marks]