Electronic and Communication — Winter 2023

Define terms: Communication Process, Modulation and Demodulation. Also enlist various needs for adopting Modulation process in communication process.

Define terms: Aperiodic signal, Channel Selectivity, Skin effect, Noise factor, Effective modulation index of multitone modulated signal, Carson’s Rule and Signal to Noise ratio (SNR).

Classify and define various signals in detail.

Write short note on Series Tuned Circuits.

Define the term passive components and describe Parallel tuned circuits with all details.

Derive a mathematical equation of a single tone Sinusoidally amplitude modulated signal. The equation of amplitude modulated wave is given by s(t)=20[1+0.8cos(2π×103t)]cos(4π×105t). Find the carrier power, the total sideband power, and the band width of AM wave.

Describe any one direct method to generate direct List out different methods of Sinusoidally modulated SSB wave generation. Describe balanced modulator-filter method in details for the same purpose.

Derive a mathematical equation of multi tone Sinusoidally amplitude modulated signal. Amodulating signal m(t)=10cos(2π×103t) is amplitude modulated with a carrier signal c(t)=50cos(2π×105t). Find the modulation index, the carrier power and the power required for transmitting AM wave.

Describe in details about envelope detector as a amplitude demodulator circuit.

Derive a mathematical equation of a single tone Sinusoidally frequency modulated signal. Also draw a FM wave in the time domain.

Describe in detail, working principle of PLL detector as a Frequency demodulator circuit.

With the neat block diagram, describe the Armstrong method of FM wave generation.

Describe the working principle of Super heterodyne radio receiver with neat block diagram.

Describe Thermal noise and Shot noise. Justify the given statement: “SNR value of signals must be greater than or equal to one.

Derive an equation of Noise factor in three stage cascaded amplifiers. A sinusoidal modulating waveform of amplitude 5 Vand a frequency of 2 KHz are1 applied to FM generator, which has a frequency sensitivity of 40 Hz/volt. Calculate the frequency deviation, modulation index, and bandwidth.

Describe Partition noise, Low frequency noise and Burst noise. An FM wave is given by s(t)=20cos(8π×106t+9sin(2π×103t)). Calculate the frequency deviation, bandwidth, and power of FM wave.

Mention the significance of Ham radio during natural calamities