Define and explain the term beam width related to antenna with a sketch.

Define and explain the term beam width related to antenna with a sketch.
by

1 Answer

Answer :

Definition: The beam width of an antenna is described as the angles created by comparing the half power point (3dB) on the main radiation lobe to its maximum power point. As an example the beam width angle is 300 which is the sum of the two angles created at the point where the field strength drops to 0.707 of max voltage at center of lobe (these point are known as half power points.)

Sketch-

image  

by

Related questions

Explain loop antenna with neat sketch. Draw radiation pattern. State its advantages and applications.

Description : Explain loop antenna with neat sketch. Draw radiation pattern. State its advantages and applications.

Last Answer : Loop antenna:-The single turn coil carrying RF current through it having length less than the wavelength.   Advantages:- 1. highly directive 2. Small size Applications:- 1. For direction finding 2. In portable receivers 3. In navigation 

Define the following terms related to antennas; (i) Antenna resistance (ii) Directivity (iii) Antenna gain (iv) Power density

Description : Define the following terms related to antennas; (i) Antenna resistance (ii) Directivity (iii) Antenna gain (iv) Power density

Last Answer : Antenna Resistance - The resistance of an antenna has two components: 1. Its radiation resistance due to conversion of power into electromagnetic waves 2. The resistance due to actual losses in the ... the transmitter power divided by the surface area of a sphere (4πR2) at that distance.

Define stub. Explain single and double stub in brief with neat sketch.

Description : Define stub. Explain single and double stub in brief with neat sketch.

Last Answer : Stub:- Stub is the piece of short circuited transmission line which is used to tune out the reactance of the load when connected across the transmission line as close as possible ... but lengths are independently adjustable. The double stub matching provides wide range of impedance matching. 

Define the following terms: (i) Polarization (ii) Antenna gain (iii)Antenna resistance (iv)Directivity

Description : Define the following terms: (i) Polarization (ii) Antenna gain (iii)Antenna resistance (iv)Directivity

Last Answer : i) Polarization:- It is defined as the direction of electric field vector in the EM wave radiated by the transmitting antenna. ii) Antenna Gain:- Antenna gain is defined as the ratio of ... in only one direction in which the radiation is maximum. That is directivity = Max. directive gain

Draw construction of Yagi-Uda antenna and explain.

Description : Draw construction of Yagi-Uda antenna and explain.

Last Answer : Explanation A Yagi-Uda antenna, commonly known as a Yagi antenna, is a directional antenna consisting of multiple parallel elements in a line, usually half-wave dipoles made of ... receiver with a transmission line and additional parasitic elements called reflector and one or more directors.

Explain how modulation reduces height of antenna and avoid mixing of signals.

Description : Explain how modulation reduces height of antenna and avoid mixing of signals.

Last Answer : Modulation reduces antenna height: For the transmission of radio signals, the antenna height must be multiple of λ/4 ,where λ is the wavelength . λ = c /f where c : is the ... will occupy different slots in the frequency domain (different channels). Thus, modulation avoids mixing of signals.

Explain half dipole antenna ( Resonant antenna ) with its radiation patteren.

Description : Explain half dipole antenna ( Resonant antenna ) with its radiation patteren. 

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

Explain duct propagation with neat sketch.

Description : Explain duct propagation with neat sketch.

Last Answer : Duct propagation is a special type and used for very high microwave frequencies. New phenomenon which occurs in super-refraction, also known as ducting. As the height above earth increases, ... in the standard atmosphere. The Duct propagation is used for very high frequencies in GHz range.

Explain “BALUN” with neat sketch

Description : Explain “BALUN” with neat sketch

Last Answer : Diagram- Explaination

Explain virtual height with respect to wave propagation with neat sketch.

Description : Explain virtual height with respect to wave propagation with neat sketch.

Last Answer : In ionization layer the incident wave refracts and bends down gradually than sharply.   The incident and refracted rays follow paths that are exactly the same as they would have been if reflection had taken place from a surface located at a greater height called virtual height of this layer. 

Explain isotropic radiator with neat sketch.

Description : Explain isotropic radiator with neat sketch. 

Last Answer : An isotropic radiator is a point source that radiates equally in all the directions. It is a hypothetical antenna used as a reference to describe real antenna. The radiation is represented by a sphere with center coincides with location of isotropic radiator.

Explain ground wave propogation with neat sketch.

Description : Explain ground wave propogation with neat sketch. 

Last Answer : Sketch-   Explanationi) It consists of direct wave which travels near the ground from Transmitter to Receiver. ii) The electromagnetic wave leaves the transmitting antenna & remains close to earth surface ... . The ground wave is the path chosen when frequency in between 30 KHz & 3 MHz 

Define the term baluns and explain where is it used?

Description : Define the term baluns and explain where is it used?

Last Answer : A type of electrical transformer used to connect an unbalanced circuit to a balanced oneORA balun is a type of transformer: it's used to convert an unbalanced signal to a balanced ... :- In audio applications, baluns convert between high-impedance unbalanced and low impedance balanced lines.

Draw the structure and state applications of: i) Ferrite loop (rod) antenna ii) Horn antenna

Description : Draw the structure and state applications of: i) Ferrite loop (rod) antenna ii) Horn antenna

Last Answer : Horn antenna: Application:- i) Used at microwave frequency. ii) Used in satellite tracking.  Ferrite loop antenna: Application:- In Am radio receiver to receive MW and SW band signals. In FM radio receiver

Write one application of following antenna i. Rectangular antenna ii. Dish antenna iii. Yagi-Uda antenna iv. Horn antenna

Description : Write one application of following antenna i. Rectangular antenna ii. Dish antenna iii. Yagi-Uda antenna iv. Horn antenna 

Last Answer : i. Rectangular antenna is used in direction finding in portable recievers. ii. Dish antenna is used to transmit and receive signal from satellite. iii. Yagi-Uda antenna is used in HF and VHF range as a TV receiving antenna. iv. Horn antenna is used in satellite tracking.

Draw radiation pattern for following antenna i) Yagi-Uda antenna ii) Loop antenna iii) Dish antenna iv) Horn antenna

Description : Draw radiation pattern for following antenna i) Yagi-Uda antenna ii) Loop antenna iii) Dish antenna iv) Horn antenna

Last Answer : Type of antenna Radiation Patteren  Yagi-Uda antenna Loop antenna Dish antenna Horn antenna 

Dish antenna is parabolic in shape and has meshy structure. Give reasons.

Description : Dish antenna is parabolic in shape and has meshy structure. Give reasons.

Last Answer : A Practical reflector employing the properties of the parabola will be a three dimensional bowl-shaped surface, obtained by revolving the parabola about the axis AB. The resulting geometric ... (directrix) is constant. These geometric properties yield an excellent microwave or light reflector. 

Describe with respect to antenna (i) radiation pattern (ii) directive gain (iii) power gam (iv) polarization

Description : Describe with respect to antenna (i) radiation pattern (ii) directive gain (iii) power gam (iv) polarization

Last Answer : (i) Radiation pattern:-A graph or diagram which tells us about the manner in which an antenna radiates more power in different directions is known as the radiation patteren of antenna.  ( ... as the direction of the electric vector in the electromagnetic wave radiated by the transmitting antenna. 

Draw Yagiuda antenna with its radiation pattern.

Description : Draw Yagiuda antenna with its radiation pattern.

Last Answer : Construction of Yagi-Uda Antenna Radiation Pattern of Yagi-Uda Antenna

An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.

Description : An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.

Last Answer : An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.

Draw the radiation pattern for Dipole antenna: (i) Half wave dipole (ii) Folded dipole.

Description : Draw the radiation pattern for Dipole antenna: (i) Half wave dipole (ii) Folded dipole.

Last Answer : The radiation pattern for Half wave dipole antenna The radiation pattern for Folded dipole antenna.

Draw the structure of horn antenna and its radiation pattern. List its any two applications.

Description : Draw the structure of horn antenna and its radiation pattern. List its any two applications.

Last Answer : The structure of horn antenna Radiation pattern of Horn Antenna Application:- i) Used at microwave frequency. ii) Used in satellite tracking 

Compare between simplex and full duplex communication on the basis of: 1) Definition 2) Sketch

Description : Compare between simplex and full duplex communication on the basis of: 1) Definition 2) Sketch

Last Answer : Compare between simplex and full duplex communication on the basis of: 1) Definition 2) Sketch

Describe ionosphere with neat sketch.

Description : Describe ionosphere with neat sketch.

Last Answer : The Ionosphere is the upper portion of the atmosphere. The ultra violet radiation from the sun will ionize the upper layer of the atmosphere. Due to ionization these part of the atmosphere becom3es ... electron density of all layers, due to this F2 layer remains present at night time  

Define critical frequency w.r. to wave propagation.

Description : Define critical frequency w.r. to wave propagation.

Last Answer : Define critical frequency w.r. to wave propagation.

Define VSWR with refernce to standing waves.

Description : Define VSWR with refernce to standing waves.

Last Answer : Voltage Standing Wave Ratio: The voltage standing wave ratio (VSWR) is the ratio of max voltage to min voltage. VSWR= VMAX /VMIN

Define sensitivity with graph.

Description : Define sensitivity with graph.

Last Answer : Define sensitivity with graph.

Define PAM, PWM, and PPM. Draw waveforms.

Description : Define PAM, PWM, and PPM. Draw waveforms.

Last Answer : Pulse amplitude modulation is defined as a process of varying the amplitude of the carrier pulse in accordance to the modulating signal variations. Pulse width modulation is defined as a ... of varying the position of the carrier pulse, in accordance to the modulating signal variations.

Define the transmission line? Draw it‟s general equivalent circuit.

Description : Define the transmission line? Draw it‟s general equivalent circuit.

Last Answer : Transmission line: A conductor or conductors designed to carry electricity or an electrical signal over large distances with minimum losses and distortion.  Equivalent circuit:

Define: 1)Frequency 2)Bandwidth 3)Wavelength 4)Time period

Description : Define: 1)Frequency 2)Bandwidth 3)Wavelength 4)Time period

Last Answer : Frequency: Frequency is the number of cycles per second. Bandwidth: A range of frequencies within a given band, in particular that used for transmitting a signal. Wavelength: Wavelength can be defined as ... for one complete cycle of vibration to pass a given point.  OR Time period=1/frequency

State the types of electromagnetic polarization? Define any one of it.

Description : State the types of electromagnetic polarization? Define any one of it.

Last Answer : Transverse electromagnetic wave:- The polarization of a plane EM wave is simply the orientation of the electric field vector with respect to the surface (i.e. looking at the horizon) If ... the field strength varies with change in polarization the wave is said to have an elliptical polarization 

Define modulation? State the desirable value of modulation index of AM.

Description : Define modulation? State the desirable value of modulation index of AM.

Last Answer : Modulation: It is the process in which any of these Parameters (Amplitude, Frequency, Phase) of high frequency signal (carrier signal) are varied in accordance with low frequency signal(modulating signal) For an AM, modulation index range is 0 to 1.

Define fading? List the causes.

Description : Define fading? List the causes.

Last Answer : 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 ... , such as irrigation, or from multiple transmission paths, irregular earth surfaces, and varying terrains.

Define electromagnetic wave and polarization.

Description : Define electromagnetic wave and polarization.

Last Answer : Electromagnetic wave:-An electromagnetic wave such as light consists of a coupled oscillating electric field and magnetic field which are always perpendicular; by convention Polarization:-polarization" of electromagnetic waves refers to the direction of the electric field.

Define selectivity and sensitivity of AM Receiver.

Description : Define selectivity and sensitivity of AM Receiver. 

Last Answer : Selectivity:-It needs to accept signals of the wanted frequency and reject other unwanted frequencies. Sensitivity:-The sensitivity of a radio receiver is its ability to amplify weak signals. It is ... the receiver input terminals to give a standard output power, measured at the output terminals. 

Define pre-emphasis. State its need. Draw the circuit of pre-emphasis.

Description : Define pre-emphasis. State its need. Draw the circuit of pre-emphasis.

Last Answer : Definition- The artificial boosting of higher modulating frequencies to reduce the effect of noise is called as pre-emphasis. Need:- The artificial boosting of higher audio modulating ... by increasing the amplitude of modulating signal at higher frequencies. Circuit diagram 

Define pulse modulation. State its types.

Description : Define pulse modulation. State its types. 

Last Answer : Pulse Modulation - consists essentially of sampling analog information signals and then converting those samples into discrete pulses. OR It consists essentially of sampling analog information signals and then converting those ... PAM - PWM - PPM  ii) Digital Pulse Modulation - PCM - DM - ADM 

Define modulation index in FM. What is maximum value of deviation ratio.

Description : Define modulation index in FM. What is maximum value of deviation ratio.

Last Answer : Modulation Index of FM: It is defined as the ratio of Frequency Deviation (δ) to the modulating signal frequency (fm). (OR)  

Define: (i) Image frequency and (ii) Double spotting

Description : Define: (i) Image frequency and (ii) Double spotting

Last Answer : i)Image frequency:- Image Frequency is defined as the signal frequency plus twice the intermediate frequency. It is denoted as fsi = fs+2fi Where, fs = Signal Frequency fi =intermediate frequency ... It is due to the poor front end selectivity i.e., inadequate image frequency rejection.

Define the terms: 1) Maximum usable frequency 2) Fading

Description : Define the terms: 1) Maximum usable frequency 2) Fading

Last Answer : 1)Maximum usable frequency:- Maximum usable frequency is defined as the limiting frequency ,when the angle of incidence is other than the normal . OR The highest frequency that can be used for sky ... which left the same source but arrived at the destination by different paths is known as fading.

Define standing wave ratio.

Description : Define standing wave ratio. 

Last Answer : Standing wave ratio is defined as the ratio of maximum voltage (Vmax) to minimum voltage (Vmin). Standing wave ratio is also defined as the ratio of maximum current (Imax) to minimum current (Imin).

Define modulation index in AM and give its formula.

Description : Define modulation index in AM and give its formula.

Last Answer : In AM wave, the modulation index (m) is defined as the ratio of the amplitude of the modulating signal (Vm ) to the amplitude of carrier signal (Vc). m = Vm / Vc

Define: Base band signal with one example.

Description : Define: Base band signal with one example.

Last Answer : The electrical equivalent of the original information signal is known as the Baseband signal. Example:-The information or the input signal to a communication system can be analog i.e., sound, picture or it can be digital e.g. the computer data.

Describe the term virtual height with the help of diagram showing ionized layer and the path of wave.

Description : Describe the term virtual height with the help of diagram showing ionized layer and the path of wave.

Last Answer : Virtual height: -The incident wave returns back to the earth due to refraction. In this process it bends down gradually and not sharply, but the incident and reflected rays follow exactly ... . It is also defined as the maximum height that the hypothetical reflected wave would have reached. 

Draw practical set-up and explain the procedure to measure selectivity of radio receiver.

Description : Draw practical set-up and explain the procedure to measure selectivity of radio receiver.

Last Answer : Procedure to measure selectivity of radio receiver: Throughout the measurement the receiver is kept tuned to desired frequency 950 Khz. Now the generator output frequency is deviated below ... the generator output voltage is adjusted to get a standard 50 miliwatt receiver output power.

State the need of stub. Explain single stub and double stub matching.

Description : State the need of stub. Explain single stub and double stub matching.

Last Answer : Stub:- Stub is the piece of short circuited transmission line which is used to tune out the reactance of the load when connected across the transmission line as close as possible. ... but lengths are independently adjustable. The double stub matching provides wide range of impedance matching.  

Explain the working of amplitude limiter in FM receiver with circuit diagram.

Description : Explain the working of amplitude limiter in FM receiver with circuit diagram.

Last Answer : Amplitude limiter: The function of amplitude limiter is to remove all amplitude variation of FM carrier voltage that may occur due to atmospheric disturbances. Use of amplitude limiter makes the system less noisy  Circuit Diagram:

Draw circuit diagram of transistor reactance modulator. Explain its working.

Description : Draw circuit diagram of transistor reactance modulator. Explain its working.

Last Answer : Explanation- A reactance modulator is illustrated in figure. It is basically a standard commonemitter class A amplifier. Resistors R1 and R2 from a voltage divider to bias ... frequency, whereas a lower capacitance increases the frequency. The circuit produces direct frequency modulations.

State and explain the concept of transmission bandwidth.

Description : State and explain the concept of transmission bandwidth.

Last Answer : Bandwidth is defined as the portion of the electromagnetic spectrum occupied by a signal We may also define the bandwidth as the frequency range over which as information signal is transmitted. Bandwidth is the ... to 15 KHZ. Therefore the bandwidth is(f2-f1) BW= f2 - f1= 15000-20=14980Hz

Explain operation of balanced slope detector with „s‟ curve.

Description : Explain operation of balanced slope detector with „s‟ curve.

Last Answer : Diagram: Explanation:   Curve: