Document information: This past examination paper is identified as an IOE/TU academic document and was cataloged from a public Google Drive archive. This independent website did not create the examination paper and is not affiliated with TU or IOE.
Rights holders can request correction or removal by emailing subeshgaming@gmail.com with this page URL and supporting details.
Most Frequently Asked Questions
Top recurring IOE board exam questions for Propagation and Antenna with verified mark schemes, formula notation, and recurrence frequency.
Showing 30 of 30 top repeated questions
Wave Propagation and Antenna Fundamentals
6 Questions
#1Repeated 5 Times[8 Marks]Wave Propagation and Antenna Fundamentals
Explain the following antenna parameters with definitions and mathematical relations: (a) Radiation Pattern and Half-Power Beamwidth (HPBW), (b) Directivity and Antenna Gain ($G = \eta D$), (c) Radiation Resistance and Input Impedance, (d) Antenna Polarization (Linear, Circular, Elliptical).
Appeared in:2081 Chaitra2080 Chaitra2079 Chaitra2077 Chaitra2076 Baisakh
#2Repeated 4 Times[6 Marks]Wave Propagation and Antenna Fundamentals
Write short notes on: (a) Effective Isotropic Radiated Power (EIRP), (b) Microstrip Patch Antenna, (c) Folded Dipole Antenna, (d) Marconi Monopole Antenna.
Appeared in:2081 Ashwin2080 Ashwin2078 Chaitra2077 Chaitra
#3Repeated 3 Times[6 Marks]Wave Propagation and Antenna Fundamentals
State and explain fundamental antenna theorems: (a) Reciprocity Theorem, (b) Compensation Theorem, and (c) Maximum Power Transfer Theorem.
Appeared in:2081 Ashwin2078 Chaitra2075 Bhadra
#4Repeated 3 Times[8 Marks]Wave Propagation and Antenna Fundamentals
What is Retarded Potential and Retarded Time? Explain the radiation mechanism of a Hertzian dipole and derive the electric and magnetic field components in the radiation far-field zone.
Appeared in:2081 Ashwin2080 Ashwin2075 Bhadra
#5Repeated 3 Times[8 Marks]Wave Propagation and Antenna Fundamentals
Derive the radiation resistance $R_{rad} = 80\pi^2 (dl/\lambda)^2$, radiated power $P_{rad}$, and magnetic vector potential $\vec{A}$ of an infinitesimal Hertzian Dipole antenna carrying current $I(t) = I_0 \cos(\omega t)$.
Appeared in:2082 Kartik2081 Chaitra2078 Bhadra
#6Repeated 3 Times[8 Marks]Wave Propagation and Antenna Fundamentals
Derive the electric field radiation pattern, input impedance ($Z_{in} \approx 73 + j42.5\ \Omega$), and directivity ($D = 1.64$ or $2.15\text{ dBi}$) of a center-fed Half-Wave Dipole antenna.
Appeared in:2082 Kartik2080 Chaitra2077 Magh
Basic Antenna Parameters and Arrays
4 Questions
#1Repeated 3 Times[8 Marks]Basic Antenna Parameters and Arrays
Derive an expression for the total electric field and array factor in the case of two isotropic point sources with equal amplitude and arbitrary phase difference $\alpha$. Distinguish between Broadside Array and End-Fire Array with radiation patterns.
Appeared in:2079 Chaitra2077 Chaitra2076 Baisakh
#2Repeated 3 Times[8 Marks]Basic Antenna Parameters and Arrays
Explain Broadside Array and End-Fire Array of $N$ isotropic point sources with uniform spacing $d$ and progressive phase shift $\alpha$. Derive the array factor $AF = \frac{\sin(N\psi/2)}{N\sin(\psi/2)}$, null directions, and directivity expressions.
Appeared in:2082 Kartik2081 Ashwin2079 Chaitra
#3Repeated 3 Times[6 Marks]Basic Antenna Parameters and Arrays
Explain the Hansen-Woodyard condition for enhanced directivity in end-fire arrays. Derive the required progressive phase shift $\alpha = -\left(\beta d + \frac{\pi}{N}\right)$ and discuss its limitations.
Appeared in:2081 Chaitra2080 Chaitra2078 Bhadra
#4Repeated 3 Times[6 Marks]Basic Antenna Parameters and Arrays
State and prove the Pattern Multiplication Theorem. Sketch polar radiation patterns of a two-element array and a four-element uniform linear array using pattern multiplication.
What is an aperture antenna? Explain the construction, working principle, feed mechanisms, and radiation characteristics of Parabolic Reflector Antennas, Cassegrain feed systems, and Horn antennas.
Appeared in:2081 Ashwin2080 Chaitra2079 Chaitra2077 Chaitra
Explain the construction, working principle, current distribution, and radiation pattern of a Yagi-Uda Antenna array. What is the role of the driven folded dipole element, reflector, and directors? Design a 5-element Yagi-Uda antenna.
Explain the working principle, geometry, design parameters (scaling factor $\tau$ and spacing factor $\sigma$), advantages, and applications of a Log-Periodic Dipole Array (LPDA) antenna. Why is it broadband?
Explain the operation, physical structure, and design principles of the Yagi-Uda Antenna (Driven element, Reflector, Directors). Calculate beamwidth, front-to-back ratio, and forward gain.
Explain Microstrip Patch Antennas. Formulate design equations for resonant frequency $f_r$, effective dielectric constant $\epsilon_{reff}$, physical length $L$, and fringe field extension $\Delta L$. List advantages and disadvantages.
Explain Horn Antennas: E-plane sectoral, H-plane sectoral, and Pyramidal horn. Derive optimum horn dimensions for maximum gain and discuss impedance matching from waveguide to free space.
Appeared in:2081 Ashwin2078 Bhadra2076 Baisakh
Propagation and Radio Frequency Spectrum
9 Questions
#1Repeated 5 Times[10 Marks]Propagation and Radio Frequency Spectrum
Explain the mechanism of ionospheric wave propagation and its structure (D, E, F1, F2 layers). Define critical frequency ($f_c$), virtual height, skip distance ($d_{\text{skip}}$), and Maximum Usable Frequency (MUF). Derive the Secant Law: $\text{MUF} = f_c \sec\theta_i = f_c \sqrt{1 + \left(\frac{d}{2h}\right)^2}$.
Appeared in:2081 Chaitra2081 Ashwin2080 Chaitra2079 Chaitra2076 Baisakh
#2Repeated 5 Times[6 Marks]Propagation and Radio Frequency Spectrum
Explain Knife-Edge Diffraction phenomenon and Fresnel Zones. How is diffraction loss calculated using the Fresnel-Kirchhoff diffraction parameter $v = h\sqrt{\frac{2(d_1+d_2)}{\lambda d_1 d_2}}$?
Appeared in:2081 Chaitra2080 Chaitra2079 Chaitra2078 Chaitra2076 Bhadra
#3Repeated 4 Times[8 Marks]Propagation and Radio Frequency Spectrum
Derive the Friis transmission formula for free space radio communication: $P_r = P_t G_t G_r \left(\frac{\lambda}{4\pi d}\right)^2$. A microwave link operates at $2.8\text{ GHz}$ over $70\text{ km}$ distance with antenna gains of $20\text{ dB}$ at both ends and transmitted power of $10\text{ W}$. Calculate the received signal power.
Appeared in:2082 Kartik2081 Ashwin2076 Baisakh2075 Bhadra
#4Repeated 3 Times[8 Marks]Propagation and Radio Frequency Spectrum
Describe space wave propagation and the Two-Ray Ground Reflection model. Explain the effect of earth curvature on the radio horizon and calculate the maximum Line-of-Sight (LOS) distance: $d = 4.12(\sqrt{h_t} + \sqrt{h_r})\text{ km}$.
Appeared in:2081 Ashwin2080 Ashwin2079 Chaitra
#5Repeated 3 Times[6 Marks]Propagation and Radio Frequency Spectrum
Explain Ground Wave (Surface Wave) Propagation. Discuss Earth curvature attenuation, ground conductivity ($\sigma$) and permittivity ($\epsilon_r$), and wave tilt during surface wave propagation.
Appeared in:2082 Kartik2080 Chaitra2077 Magh
#6Repeated 3 Times[8 Marks]Propagation and Radio Frequency Spectrum
Explain Line-of-Sight (LOS) Space Wave Propagation. Derive the path loss formula including direct and ground-reflected rays, radio horizon distance $d \approx 4.12(\sqrt{h_t} + \sqrt{h_r})\text{ km}$, and effective Earth radius factor ($k = 4/3$).
Appeared in:2082 Kartik2081 Chaitra2079 Chaitra
#7Repeated 3 Times[8 Marks]Propagation and Radio Frequency Spectrum
Explain Critical Frequency ($f_c$), Maximum Usable Frequency ($MUF = f_c \sec \theta_i$), Skip Distance ($D_{skip}$), and Virtual Height in ionospheric sky wave propagation. Calculate MUF for given plasma density and incident angle.
Appeared in:2082 Kartik2081 Ashwin2080 Chaitra
#8Repeated 2 Times[6 Marks]Propagation and Radio Frequency Spectrum
Explain Ground (Surface) Wave propagation over plane and spherical earth. Discuss Sommerfeld's numerical distance and factors causing severe attenuation of surface waves at higher frequencies.
Appeared in:2081 Chaitra2076 Bhadra
#9Repeated 2 Times[6 Marks]Propagation and Radio Frequency Spectrum
Explain Tropospheric Wave propagation. Describe Tropospheric Scatter communication, atmospheric duct propagation (surface and elevated ducts), and abnormal refraction.
Appeared in:2081 Ashwin2079 Chaitra
Propagation between Antennas
2 Questions
#1Repeated 3 Times[8 Marks]Propagation between Antennas
What is Acceptance Angle? Derive the expression for Numerical Aperture ($\text{NA} = \sqrt{n_1^2 - n_2^2}$) of a step-index optical fiber. Explain attenuation and chromatic dispersion mechanisms.
Appeared in:2081 Chaitra2079 Chaitra2076 Baisakh
#2Repeated 3 Times[8 Marks]Propagation between Antennas
Explain Optical Wave Propagation through step-index optical fiber waveguides: Total Internal Reflection, Numerical Aperture ($NA = \sqrt{n_1^2 - n_2^2}$), normalized frequency ($V$-number), and modal dispersion in step-index vs graded-index fibers.
Chapter-wise Units & Micro-Syllabus Topics (6 Units)
1. Wave Propagation and Antenna Fundamentals
1.1Radiation Phenomena in a Conductor
1.2Function of Antenna
1.3Retarded Potentials: EM Wave Generation and Propagation
1.4Radiated Electric and Magnetic Fields in EM Wave
1.5Radiation Patterns and Input Impedance of Very Short Dipole, Short Dipole and Long Dipoles
1.6Antenna Theorems 1.6.1 Reciprocity Theorem 1.6.2 Superposition Theorem 1.6.3 Thevenin Theorem 1.6.4 Maximum Power Transfer Theorem 1.6.5 Compensation Theorem 1.6.6 Equality of Directional Patterns 1.6.7 Equivalence of Receiving and Transmitting Impedances
2. Basic Antenna Parameters and Arrays
2.1Antenna Parameters
2.2Pattern Multiplications
2.3Two Dimensional Antenna Arrays 2.3.1 Broadside Arrays 2.3.2 End Fire Arrays 2.3.3 Parasitic Arrays 2.3.4 Collinear Arrays
2.4Arrays of Two Point Sources 2.4.1 With Equal Amplitude and Same Phase 2.4.2 With Equal Amplitude and Opposite Phase 2.4.3 With Equal Amplitude and Quadrature Phase 2.4.4 With Any Amplitude and Any Phase
3. Antenna Classifications
3.1Electromagnetic Spectrum
3.2Criteria for Antenna Design
3.3Isotropic Antenna
3.4Omnidirectional Antennas
3.5Directional Antennas
3.6Travelling and Standing Wave Antennas: Long Wire Antenna, Vee Antennas, Rhombic Antenna