RF Modelling and Antennas - May 2016

MU Electronics and Telecom Engineering (Semester 5)

Total marks: --
Total time: -- INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary 1(a) Explain the Hazards of Electromagnetic Radiation. 5 marks

1(b) Explain the radiation mechanism of antenna with single wire system. 5 marks

1(c) Explain the use of Richard transformation and Kurodas Identity in RF filter design 5 marks

1(d) Derive an expression for arry of two isotropic sources with same amplitude and in phase. 5 marks

2(a) Explain the RF behavior of resistor, capacitor and inductor. 5 marks

2(b) Discuss the design procedure for filter using image parameters method. 5 marks

3(a) Design a maximally flat LPF with a cut off frequency of 2 Ghz. The generator and load impedance is 50&Omega 5 marks

3(b) Derive an expression for array factor of N element linear array, where all elements are equally fed and spaced. Also find the expression for the position of principle maxima, 's and secondary maxima. 5 marks

4(a) A radio link has 15 watt transmitter connected to an antenna of 2.5 m² effective aperture at 5 Ghz. The receiving antenna has an effective aperture of 0.5 m² and is located at a 15 km line of sight distance from transmitting antenna. Assume lossless antennas. Find power delivered to the receiver. 5 marks

4(b) Derive an expression for E field and H field of infinitesimal dipole antenna. 5 marks

5(a) What is the folded dipole Antenna? Draw its typical structure and explain working mechanism. Give its advantages. 5 marks

5(b) What is Dolph-Chebyshev array? Explain the steps involved in design of Dolph-chebyshev array. 5 marks

Write short notes

6(b) Log periodic Antenna 5 marks

6(c) Loop antenna 5 marks

6(d) Horn antenna 5 marks