SONAR b. Subsurface communication c. Radio navigation d. Phase b. Frequency c. Amplitude d. Wave equation. Sinusoidal b. Rectangular c.
Antenna & Wave Propagation - Electronic Engineering (MCQ) questions & answers
Square d. Solid bodies b. Ionized particles c. All of the above. Reflected b. Refracted c. Radiated d. D-region b. Normal E-region c. Sporadic E-region d. Appleton region. Electric field intensity b.
Magnetic field intensity c. Current density d.Antenna Fundamentals Let's get right down to the study of antennas and Antenna Basics. Suppose one day you're walking down the street and a kind but impatient person runs up and asks you to design an antenna for them.
Well then, you've come to the right place.ANTENNA BASED VIVA INTERVIEW QUESTION AND ANSWERS
Before we can design an antenna or discuss antenna types, we must understand the basics of antennas, which are the fundamental parameters that characterize an antenna. So let us learn something. We'll start with frequency and step through radiation patterns, directivity and gain, and ultimately close with an explanation on why antennas radiate. Jump ahead if this is already familiar to you. Frequency The basics of sinusoids sine and cosine waveswavelength, frequency and the speed of light.
More Advanced Frequency Information A discussion on how all waveforms in the universe are made up of the sum of sinusoids simple waves This helps explains why in antenna theory we always discuss wavelength and frequency no matter what signal information we want to transmit.
Frequency Bands No discussion on antenna fundamentals is complete without a real-world list of frequency bands. Radiation Pattern The radiation pattern for an antenna is defined on this page. We have 3D graphs of real antenna radiation patterns, with a discussion on isotropic, omnidirectional and directional radiation patterns.
Radiation patterns are of the utmost importance in the discussion of antenna basics. Field Regions The introduction to antennas continues with a discussion of Field Regions.
Directivity Directivity is fundamental to antennas. It is a measure of how "directional" an antenna's radiation pattern is. Antenna Efficiency An antenna's efficiency is a measure of how much power is radiated by the antenna relative to the antenna input power. Antenna Gain Antenna Gain is a measure of power radiated in a particular direction typically the peak direction of radiation.
Beamwidths and Sidelobes An antenna's radiation pattern in the far field is often characterized by it's beamwidth and sidelobe levels. This introduction to antenas illustrates this with an example. Impedance Antenna Impedance is presented as the ratio of voltage to current at the antenna's terminals. Low- and High-Frequency models are presented for transmission lines. The fundamentals of antenna theory requires that the antenna be "impedance matched" to the transmission line or the antenna will not radiate.
The concept of VSWR is introduced as a measure of how well matched an antenna is. Bandwidth The bandwidth of an antenna is the frequency range over which the antenna radiates. The bandwidth can be defined in different ways; this page presents an introduction to antenna bandwidth. Polarization of Waves All electromagnetic plane waves have an associated polarization.
The antenna concepts of Linear, Circular and elliptical polarization are presented. Polarization of Antennas Antennas are also classified by their polarization; this defines the type of plane wave polarization the antenna is most sensitive to.
This is a fundamental antenna concept. Effective Aperture Effective aperture is a basic antenna concept that is a measure of the power captured by an antenna from a plane wave. Effective aperture can be expressed as a function of the antenna gain and the wavelength of interest. Friis Transmission Equation Friis Transmission Formula is the most fundamental equation of antenna theory.
This equation relates transmit power, antenna gains, distance and wavelength to received power.
Radar Test Engineer Interview Questions & Answers
This page is a must-read for those interested in antenna theory.Draw the block diagram of a Pulsed radar and explain its operation 2. Explain about the frequencies used for radar 5. Discuss in detail the choice of various parameters that are affecting the radar range 6. Derive the range equation and discuss about its limitations 7. If it is defined to detect a target with a cross section of 12sq. What is the maximum range of the radar.
What is meant by minimum detectable signal in radar. Discuss the effects of integration of radar pulses 2. What are the desirable pulse characteristics and the factors that govern them in a radar system 3. Discuss about detection of signals in noise 4. Describe the different noise components present in radar systems 5.
Explain about PRF and range ambiguities 6. Explain about radar cross section of targets. Explain about Doppler effect 2. Explain the operation of CW radar with neat block diagram 3. Differentiate the operation of pulse radar from simple CW radar 6. Draw the block diagram of non coherent MTI radar and explain the function of each block in detail 7. Explain the advantages of non coherent MTI Radar 8.
Explain the applications of CW radar. Explain the principle of Doppler effect and its application CW radar. Derive an expression for unambiguous range of a two frequency CW radar. Explain phase comparison monopulse tracking radar technique 4.
Explain the block diagram of AGC portion of tracking radar receiver 5. Explain about sequential Lobing 6. What are the advantages of monopulse radar over conical scan radar? Distinguish between search radar and tracking radar? Compare the tracking techniques 9. How is radar target acquired in a typical radar? Explain the characteristics of a matched filter receiver with necessary equations 2.
Explain about matched and non —matched filters 3. Explain the characteristics of a cross —correlation receiver with a block diagram 4 Derive and explain the efficiency of non-matched filters 5. Explain about matched filter with non —white noise.
Define the following terms a noise figure b noise temperature c system noise 2. Explain various types of radar displays 3. Three networks units ,each of 6db noise figure and 10db, 6db and 3db gains respectively are cascaded.An antenna is an electrical conductor or system of conductors.
Wave propagation is any of the ways in which waves travel. Having covered the process in class these past weeks you are now well capable of taking up the quiz below with ease. Give it a try and share your score. Forgot your password? Speak now. Antenna And Wave Propagation Questions! Trivia Quiz. Please take the quiz to rate it.
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Remove Excerpt. Removing question excerpt is a premium feature. In a travelling wave antenna if the length of the wire increases the major lobes.
When a wave propagating in a free space enters the ionosphere, its velocity. If the direction of propagation of an electromagnetic wave is in z-direction,the polarization is in. If the mouth diameter of a parabolic antenna is 2. Back to top. Sign In with your ProProfs account. Not registered yet? Sign Up. I agree to the Terms of Services and Privacy Notice.
Already have an account?A person, who needs to convey a thought, an idea or a doubt, can do so by voice communication. The following illustration shows two individuals communicating with each other. Here, communication takes place through sound waves. However, if two people want to communicate who are at longer distances, then we have to convert these sound waves into electromagnetic waves.
The device, which converts the required information signal into electromagnetic waves, is known as an Antenna. An Antenna is a transducer, which converts electrical power into electromagnetic waves and vice versa.
A transmitting antenna is one, which converts electrical signals into electromagnetic waves and radiates them. A receiving antenna is one, which converts electromagnetic waves from the received beam into electrical signals. Antenna can also be termed as an Aerial.
Plural of it is, antennae or antennas. Now-adays, antennas have undergone many changes, in accordance with their size and shape. There are many types of antennas depending upon their wide variety of applications. In this chapter, you are going to learn the basic concepts of antenna, specifications and different types of antennas.
In the field of communication systems, whenever the need for wireless communication arises, there occurs the necessity of an antenna. Antenna has the capability of sending or receiving the electromagnetic waves for the sake of communication, where you cannot expect to lay down a wiring system.
The following scenario explains this. In order to contact a remote area, the wiring has to be laid down throughout the whole route along the valleys, the mountains, the tedious paths, the tunnels etc.
The evolution of wireless technology has made this whole process very simple. Antenna is the key element of this wireless technology. In the above image, the antennas help the communication to be established in the whole area, including the valleys and mountains.
This process would obviously be easier than laying a wiring system throughout the area. The sole functionality of an antenna is power radiation or reception. Antenna whether it transmits or receives or does both can be connected to the circuitry at the station through a transmission line. The functioning of an antenna depends upon the radiation mechanism of a transmission line.
A conductor, which is designed to carry current over large distances with minimum losses, is termed as a transmission line. For example, a wire, which is connected to an antenna. A transmission line conducting current with uniform velocity, and the line being a straight one with infinite extent, radiates no power. If the power has to be radiated, though the current conduction is with uniform velocity, the wire or transmission line should be bent, truncated or terminated.
If this transmission line has current, which accelerates or decelerates with a timevarying constant, then it radiates the power even though the wire is straight.
Antenna Theory - Fundamentals
The device or tube, if bent or terminated to radiate energy, then it is called as waveguide. These are especially used for the microwave transmission or reception. The above diagram represents a waveguide, which acts as an antenna. The power from the transmission line travels through the waveguide which has an aperture, to radiate the energy. Following are the types of antennas according to the physical structure. You will learn about these antennas in later chapters.
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Visit Wisdom jobs to look into the various Antenna jobs available along with the training and assessment material for improving your knowledge base and sample resumes for a winning job and Antenna interview questions. Visit our Antenna job interview questions and answers pag e designed by our experts and also those collected from individuals who already attended Antenna jobs, for both freshers and experienced so as to make yourself acquainted with the nature of the interview.
Answer : Antenna is a transition device or a transducer between a guided wave and a free space wave or vice-versa. Antenna is also said to be an impedance transforming device. Question 2. Answer : Radiation pattern is the relative distribution of radiated power as a function of distance in space. It is a graph which shows the variation in actual field strength of the EM wave at all points which are at equal distance from the antenna. Question 3. Define Radiation Intensity?
Answer : The power radiated from an antenna per unit solid angle is called the radiation intensity U watts per steradian or per square degree. The radiation intensity is independent of distance. Question 4. Define Beam Efficiency? Question 5. Define Directivity? Answer : The directivity of an antenna is equal to the ratio of the maximum power density P q,f max to its average value over a sphere as observed in the far field of an antenna.
Question 6. Answer : Effective aperture. Scattering aperture. Loss aperture. Collecting aperture. Physical aperture. Question 7. Define Different Types Of Aperture? Answer : Effective aperture Ae : It is the area over which the power is extracted from the incident wave and delivered to the load is called effective aperture. Scattering aperture As : It is the ratio of the reradiated power to the power density of the incident wave.
Loss aperture Ae : It is the area of the antenna which dissipates power as heat.An antenna is an electrical conductor or system of conductors. Wave propagation is any of the ways in which waves travel. Having covered the process in class these past weeks you are now well capable of taking up the quiz below with ease. Give it a try and share your score.
Forgot your password? Speak now. Antenna And Wave Propagation Questions! Trivia Quiz. Please take the quiz to rate it. All questions 5 questions 6 questions 7 questions 8 questions 9 questions 10 questions 11 questions 12 questions 13 questions 14 questions 15 questions 16 questions 17 questions 18 questions 19 questions 20 questions 21 questions 22 questions 23 questions 24 questions 25 questions 26 questions 27 questions 28 questions 29 questions 30 questions 31 questions 32 questions.
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Play as Quiz Flashcard. Title of New Duplicated Quiz:. Duplicate Quiz Cancel. More Radio Quizzes. Private Pilot-radio Telephony Radio Propagation. Featured Quizzes. What do you know about Coronavirus? Myths and Facts! Related Topics. Questions and Answers. Remove Excerpt. Removing question excerpt is a premium feature. In a travelling wave antenna if the length of the wire increases the major lobes. When a wave propagating in a free space enters the ionosphere, its velocity.
If the direction of propagation of an electromagnetic wave is in z-direction,the polarization is in. If the mouth diameter of a parabolic antenna is 2.