Description : An isotropic radiator is A. in the northern hemisphere B. an antenna high enough in the air C. an antenna whose directive pattern is substantially incredible D. a hypothetical, omnidirectional antenna
Last Answer : D. a hypothetical, omnidirectional antenna
Description : The parasitic element of an antenna system will A. decrease its directivity B. increase its directivity C. give the antenna unidirectional properties D. both B and C
Last Answer : D. both B and C
Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB
Last Answer : C. 3.9 dB
Description : Discone radiation pattern is ______. A. omnidirectional/vertical polarized B. unidirectional C. bidirectional D. figure of eight
Last Answer : A. omnidirectional/vertical polarized
Description : Radiation pattern of a discone. A. Unidirectional B. Bidirectional C. Omnidirectional D. Figure of eight
Last Answer : C. Omnidirectional
Description : It is useful to refer to an isotropic radiator. A. when comparing the gains of directional antennas B. when testing a transmission line for standing wave ratio C. when (in the northern hemisphere) directing the transmission D. when using a dummy load to tune a transmitter
Last Answer : A. when comparing the gains of directional antennas
Description : A theoretical reference antenna that provides a comparison for antenna measurements. A. Marconi antenna B. Isotropic radiator C. Yagi-Uda array D. Whip antenna
Last Answer : B. Isotropic radiator
Description : The product of the radiated RF power of a transmitter and the gain of the antenna system in a given direction relative to an isotropic radiator is called ____. A. Effective Radiated Power (ERP) B. Effective Isotropic Radiated Power (EIRP) C. Radiated Power D. Transmit Power
Last Answer : B. Effective Isotropic Radiated Power (EIRP)
Description : When is it useful to refer to an isotropic radiator? A. When comparing the gains of directional antennas B. When testing a transmission line for standing wave ratio C. When (in the northern ... ) directing the transmission in a southerly direction D. When using a dummy load to tune a transmitter
Last Answer : A. When comparing the gains of directional antennas
Description : Stacking elements in a transmitting antenna system A. increases the field strength at the receiving antenna B. increases the directivity of the transmitter antenna C. decrease the size of the lobe in the radiation pattern D. both A and B
Last Answer : D. both A and B
Description : A vertical loop antenna has a A. unidirectional radiation pattern in the horizontal plane B. unidirectional radiation pattern in the vertical plane C. omnidirectional radiation pattern in the horizontal plane D. a bidirectional radiation pattern in the horizontal plane
Last Answer : D. a bidirectional radiation pattern in the horizontal plane
Description : Best description of a collinear and broadside antenna radiation pattern. A. Bidirectional B. Perfect circle C. Unidirectional D. Omnidirectional
Last Answer : A. Bidirectional
Description : Radiation characteristics of a dipole A. Figure of eight B. Omnidirectional C. Bidirectional D. Unidirectional
Last Answer : C. Bidirectional
Description : What is the ratio of the maximum radiation intensity to the average radiation intensity? A. Aperture gain B. Directivity gain C. Transmission gain D. Power gain
Last Answer : B. Directivity gain
Description : Comparing the signal strength arriving at the driven element from the desired direction to the signal strength reaching the driver from the opposite direction. A. Directivity B. Sensitivity C. Beamwidth D. Front-to-back ratio
Last Answer : D. Front-to-back ratio
Description : Which of the following improves antenna directivity? A. Driven element B. Reflector element C. Director element D. Parasitic element
Last Answer : D. Parasitic element
Description : ______ is the measurement of a unilateral antenna properties of directivity A. Phase angle B. Antenna gain C. Beamwidth D. Bandwidth
Last Answer : C. Beamwidth
Description : What determines the ability of radar to determine the bearing to a target? A. Speed of light B. Speed of target C. Antenna directivity D. Frequency of signal
Last Answer : C. Antenna directivity
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.
Description : hat two factors determine the directivity pattern of the parasitic array?
Last Answer : Length of the parasitic element (tuning) and spacing between the parasitic and driven elements.
Description : Stacking antennas at various angles results in A. a more omnidirectional reception B. a more unidirectional reception C. a more omnidirectional reception D. an overall reception signal increase
Last Answer : A. a more omnidirectional reception
Description : What is the radiation characteristic of a dipole antenna? A. Omnidirectional B. Bidirectional C. Unidirectional D. Hemispherical
Last Answer : B. Bidirectional
Description : Which antenna is not properly terminated? A. Resonant B. Non-resonant C. Isotropic D. Whip
Last Answer : A. Resonant
Description : What antenna radiates equally in all directions? A. Vertical antenna B. isotropic antenna C. Horizontal antenna D. Dipole antenna
Last Answer : B. isotropic antenna
Description : Which of the following antennas is used for testing and adjusting a transmitter for proper modulation, amplifier operation and frequency accuracy? A. Elementary B. Real C. Isotropic D. Dummy
Last Answer : D. Dummy
Description : What is the gain of isotropic antenna? A. 10 B. 1 C. 10 D. 100
Last Answer : B. 1
Description : An antenna with unity gain A. Rhombic B. Half-wave dipole C. Isotropic D. Whip
Last Answer : C. Isotropic
Description : In testing transmitter to prevent interfering with other stations, which type of antenna must be used? A. Void antenna B. Dummy antenna C. Hertzian antenna D. Isotropic antenna
Last Answer : B. Dummy antenna
Description : What is the gain of the Hertzian dipole over isotropic antenna? A. 1.64 dB B. 2.15 dB C. 1.76 dB D. 1.55 dB
Last Answer : C. 1.76 dB
Description : Which of the following antennas require good grounding? A. Yagi antenna B. Hertz antenna C. Marconi antenna D. Isotropic antenna
Last Answer : C. Marconi antenna
Description : What optical source radiates light uniformly in all directions? A. Isotropic source B. Lambertian source C. Voltage source D. Ideal source
Last Answer : B. Lambertian source
Description : The product of antenna input power and the antenna power gain expressed in kW is called __. A. Effective Radiated Power (ERP) B. Effective Isotropic Radiated Power (EIRP) C. Radiated Power D. Transmit Power
Last Answer : A. Effective Radiated Power (ERP)
Description : Antenna which is not properly terminated A. Isotropic B. Non-resonant C. Whip D. Resonant
Last Answer : D. Resonant
Description : An antenna that can only receive a television signal. A. Isotropic antenna B. TVRO C. Reference antenna D. Yagi antenna
Last Answer : B. TVRO
Description : Unity gain antenna A. Isotropic B. Rhombic C. Half-wave dipole D. Dummy
Last Answer : A. Isotropic
Description : Gain of an isotropic antenna A. -1 dB B. 1 dB C. 0 dB D. 2 dB
Last Answer : C. 0 dB
Description : ECE Board Exam March 1996 A type of an underground antenna is a/an __________ antenna. A. Hertz B. isotropic C. parabolic D. Marconi
Last Answer : A. Hertz
Description : ECE Board Exam March 1996 The standard reference antenna for the directive gain is ___________. A. elementary doublet B. isotropic antenna C. half-wave dipole D. infinitesimal dipole
Description : ECE Board Exam March 1996 EIRP stands for _______________. A. effective isotropic refracted power B. effective and ideal radiated power C. effective isotropic reflected power D. effective isotropic radiated power
Last Answer : D. effective isotropic radiated power
Description : For a shortened vertical antenna, where should a loading coil be placed to minimize losses and produce the most effective performance? A. As low as possible on the vertical radiator B. Near the center of the vertical radiator C. As close to the transmitter as possible D. At a voltage node
Last Answer : B. Near the center of the vertical radiator
Description : One of the following prevents a transmitter from emitting a signal that interferes with other stations on frequency during the test. A. Use of low height antenna B. Use of grounded antenna C. Use of dummy antenna D. Use of shielded antenna radiator
Last Answer : C. Use of dummy antenna
Description : Due to its construction, the component in figure 'A' shown in the illustration has which of the listed advantages compared to bipolar devices? EL-0078 A. Operates with higher voltages and ... as a controllable rectifier. D. Has very high input resistance and uses practically no gate current.
Last Answer : Answer: D
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.
Description : One of the following is not a reason for the use of an earth mat A. impossibility of a good ground connection B. provision of an earth for the antenna C. protection of personnel working underneath D. improvement of the radiation pattern of the antenna
Last Answer : C. protection of personnel working underneath
Description : The purpose of stacking elements on an antenna. A. Sharper directional pattern B. increased gain C. Improved bandpass D. All of these
Last Answer : D. All of these
Description : Which antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization? A. Marconi antenna B. Discone antenna C. Horn antenna D. Helical antenna
Last Answer : A. Marconi antenna
Description : Satellite the orbits in a circular pattern with an angular velocity equal to that of the earth A. Geostationary B. Early Bird I C. Syncorn I D. Stationary satellite
Last Answer : A. Geostationary
Description : The smallest beam of a satellite antenna radiation pattern A. Zone beam B. Hemispheric beam C. Spot beam D. Global beam
Last Answer : C. Spot beam
Description : Is the geographical representation of a satellite antenna radiation pattern A. Footprint B. Spot C. Earth D. Region
Last Answer : A. Footprint
Description : ___________ is a satellite that rotates around the earth in a low-altitude elliptical or circular pattern. A. Geosynchronous satellite B. Nonsynchronous satellite C. Prograde satellite D. Retrograde satellite
Last Answer : B. Nonsynchronous satellite