Recent questions tagged principles-of-electronic-communication

Description : Draw the practical AM diode detector circuit. Sketch its input and output waveforms. 

Last Answer : Practical AM diode detector 1. Skip distance:-Skip distance is defined as the shortest distance from a transmitter, measured along the surface of earth at which a sky wave of fixed frequency ... had taken place from a surface located at a greater height, called Virtual height of this layer.

Description : Explain Tropospheric scatter propagation with sketch.

Last Answer : As the name implies, troposcatter uses the troposphere as the region that affects the radio signals being transmitted, returning them to Earth so that they can be received by the ... of "blurring" the overall received signal and this makes high speed data transmissions difficult.

Description : Draw and label PLL based FM detector.

Last Answer : Draw and label PLL based FM detector.

Description : Write any one application of the following range. 1. Radio frequency 2. IR frequency 3. Medium frequency 

Last Answer : Application of 1. Radio Frequency- Radar signals and communication 2. IR Frequency- LED, Laser, TV remote, Used for directed links e.g. to connect different buildings via laser links. 3. Medium Frequency- AM broadcasting.

Description : A 400 W carrier is amplitude modulated to a depth of 75%.Calculate the total power in AM wave. (i) Explain the types of noise in a communication system. (ii) Compare simplex and duplex mode of communication.

Last Answer : (i) Noise: Noise is any spurious or undesired disturbances that mask the received signal in a communication system. a) Atmospheric Noise: Atmospheric Noise is also known as static noise which is the ... remote control ExamplesWalkytalky,telephone,mobile,Radar, FAX,Pager 4

Description : Derive a mathematical expression for AM wave.

Last Answer : Derive a mathematical expression for AM wave.

Description : Explain the working of half dipole antenna with its radiation pattern. 

Last Answer : Half wave dipole antenna diagram Explanation: 1. It is a resonant antenna 2. It is exact half wavelength (λ /2) long & open circuited at one end. 3. The dipole ... waves exist. Hence radiation pattern is bidirectional. The radiation pattern of half wave dipole antenna is -

Description : Compare sky wave and space wave propagation w.r.t. following points. (i) Frequency range (ii) Effect of fading (iii)Polarization (iv)Application

Last Answer : Sr. No  Parameters Sky Wave Propagation Space Wave Propagation 1 Frequency range 3 MHz to 30 MHz  Above 30 MHz 2 Effect of fading Problem of fading is ... horizontally Polarized 4 Application RadioBroadcasting (SW Range) Used for TV and FM broadcasting

Description : Draw the block diagram of AM. Super heterodyne ratio receiver and state the function of each block

Last Answer : AM super heterodyne receiver works on the principle of super heterodyning. In the super heterodyne receiver, the incoming signal voltage is combined with a Signal generated in the receiver. The ... constant output level at the speaker even though the signal strength at the antenna varies.

Description : Explain Electromagnetic spectrum. 

Last Answer : The information signal should be first converted into an electromagnetic signal before transmission because the wireless transmission takes place using electromagnetic waves. The electromagnetic waves are oscillations which ... This entire range of frequency of EM waves is called EM spectrum.

Description : Explain structure of rectangular microstrip patch antenna with its radiation pattern. 

Last Answer : In telecommunication, a microstrip antenna (also known as a printed antenna) usually means an antenna fabricated using microstrip techniques on a printed circuit board (PCB).It is a kind of ... microstrip transmission line with equivalent loads on either end to represent the radiation loss.

Description : Explain why reception for high frequency band is better during night time.

Last Answer : In sky wave propagation, the transmitted signal travels into the upper atmosphere where it is bent or reflected back to earth. This bending or reflection of signal takes place due to the presence ... reflected signal and hence the reception for high frequency band is better during night time.

Description : Sketch AM signal in (1)Time domain (2)Frequency domain.

Last Answer : AM in Time domain AM in frequency domain

Description : Compare narrow band FM with wide-band FM w.r.t. following points. (i) Modulation index (ii) Maximum deviation (iii)Range of modulating frequency (iv)Application

Last Answer : Sr. No Parameters Narrow band FM Wide band FM 1 Modulation index Less than or slightly greater than 1 Greater than 1  2 Maximum deviation ... like police wireless, ambulance etc. Entertainment broadcasting can be used for high quality music transmission 

Description : Explain the concept of De-emphasis with neat diagram. 

Last Answer : In the De-emphasis circuit, by reducing the amplitude level of the received high frequency signal by the same amount as the increase in pre-emphasis is termed as De-emphasis. The pre- ... de-emphasis circuit is a low pass filter or integrator which allows only low frequencies to pass. 

Description : Draw the basic block diagram of Electronic communication system. State the function of transmitter.

Last Answer : Block diagram: Transmitter The function of the transmitter is to process the electrical signal from different aspects. For example in radio broadcasting the electrical signal obtained from sound ... the message signal are done just to ease the transmission of the signal through the channel.

Description : Sketch the radiation pattern of Yagi-Uda antenna.

Last Answer : Sketch the radiation pattern of Yagi-Uda antenna.

Description : Define fading w.r.t. wave propagation. 

Last Answer : Fading: The fluctuation in signal strength at a receiver, which is mainly due to the interference of two waves which left the same source but arrived at the destination by different paths, is known as fading. 

Description : Write the IF value of (i) FM ratio recevier. (ii) MW band AM.

Last Answer : (i) 10.7 Mhz (ii) 455 Khz

Description : Define modulation index of FM.

Last Answer : Modulation index of FM is defined as the ratio of the frequency deviation to the modulating frequency.

Description : Define the term signal to noise ratio. 

Last Answer : Signal to Noise ratio: The ratio of the strength of an electrical or other signal carrying information to that of unwanted interference is called as signal to noise ratio. OR Signal to Noise Ratio is defined as ... the same point. S/N=Ps/Pn where,Ps=Signal Power Pn=Noise Power at the same point