Antennas and wave Propagation (EC-602) - Important Questions

What is retarded potential, how does it account for finite propagation speed, how does it differ from static potential, and why is it important for radiation / antenna theory?

Write a short note on any two of: Oscillating Electric Dipole, Turnstile antenna, Relation between MUF and skip distance, Numerical tool for antenna analysis.

Explain the working principle of a quarter-wave monopole antenna, derive the radiation pattern expression, and discuss its applications.

Discuss the significance of the far-field approximation in antenna design and analysis.

Derive the radiated electric and magnetic field components of an alternating current element / oscillating electric dipole.

Derive an equation of potential function for sinusoidal operations of an antenna.

Explain the near-field and far-field regions of an antenna. What are the primary differences between them in terms of field components?

Write some of the practical applications of short antenna.

Discuss the power radiated by an oscillating electric dipole. How is this power dependent on the frequency and current distribution?

Derive an expression for the power radiated by a quarter-wave monopole antenna.

Discuss the significance of retarded potential and radiation resistance.

Explain the effect of ground conductivity and permittivity (earth) on the vertical radiation patterns of antennas.

Explain the directional characteristics / properties of dipole antennas.

Explain the directional properties of dipole antennas and analyze the influence of dipole length and feed-point position on them.

Describe horizontal patterns in broadcast antenna arrays. How do they influence the coverage area of AM/FM broadcast systems?

What do you mean by antenna? Write some of the properties of antenna.

Define directivity, radiation pattern, and antenna arrays.

Derive a relation and find necessary equations for transmission between the two antennas.

Explain the significance of antenna gain and compute effective aperture from gain and frequency.

Define antenna gain and classify and explain its types.

Derive and explain the relation between antenna efficiency and effective length.

Discuss the pattern multiplication of an antenna. Explain the effect of earth on vertical patterns.

Discuss the Taylor synthesis of sum patterns of an antenna array system.

Explain the construction, operation, characteristics and radiation pattern of a Yagi-Uda antenna, including the roles of reflector and directors and its use for TV reception.

Explain the construction and working principle of a log-periodic antenna and how its structure enables wideband operation

Discuss about the radiation pattern and design principles of a long wire antenna. How does its length influence its performance?

Write short notes on helical antenna, horn antennas and rhombic antenna.

Explain folded dipole antenna. Derive the current equation for this antenna.

Explain the construction and basic principles of operation of a helical antenna in normal mode and axial mode.

Design a 6-element Yagi-Uda antenna for specified gain and operating frequency.

Define the following terms:

Write short notes on:

Explain the construction and radiation mechanism of a microstrip antenna along with its advantages and disadvantages.

Describe slot antennas and derive the radiation pattern of a rectangular slot in an infinite ground plane.

Discuss the advantages of tapered apertures over uniform apertures and explain its application in reducing side lobe levels in antenna systems.

Explain Babinet's principle and complementary antennas.

How does aperture blockage affect the performance of reflector antennas? Explain.

Discuss the principle of operation and design and construction considerations of a parabolic reflector antenna.

Explain in detail flat sheet and corner reflector antennas.

Determine the width and length of a rectangular microstrip patch antenna for a given resonant frequency, dielectric constant and substrate height.

What do you mean by horn antenna? While measuring the gain of a horn antenna the gain oscillator is set for 9 GHz frequency and the attenuation inserted was found to be 9.8 dB. Calculate the gain of the horn, the distance between two horn is 35 cm.

Explain feeding structures of antennas.

Define and explain MUF, LUF and skip distance in sky wave propagation and their relevance to long-distance communication.

Discuss the transition between surface and space waves in ground wave propagation. How does terrain affect this transition?

Describe the effects of the environment on the propagation of radio waves. Explain how atmospheric conditions, terrain and obstacles influence wave behavior.

Discuss super refraction and scattering in space wave propagation and their effect on signal transmission.

Calculate the Maximum Usable Frequency (MUF) given critical frequency and angle of incidence.

Describe tropospheric scattering and its effect on radio wave propagation.

Discuss the effect of frequency and terrain on ground wave propagation. Provide a practical example.

Discuss some of the fundamentals of electromagnetic waves. Discuss the types of radio waves propagation.

Discuss super refraction and explain tropospheric propagation.

Derive the relation between Maximum Usable Frequency (MUF) and skip distance.

Describe the troposphere and explain how tropospheric ducts enable microwave propagation.

Show that Ionosphere act as a variable refractive index medium.