Description : Which of the following refers to the smallest beam of a satellite antenna’s radiation pattern A. Global beam B. Spot beam C. Zone beam D. Hemispheric beam
Last Answer : B. Spot beam
Description : Which of the following refers to the smallest beam of satellite antenna’s radiation pattern? A. Hemispheric beam B. Spot beam C. Zone beam D. Global beam
Description : A satellite beam that covers almost 42.4% of the earths surface. A. Zone beam B. Hemispheric beam C. Spot beam D. Global beam
Last Answer : D. Global beam
Description : A satellite beam that covers almost 42.4% of earths surface. A. Spot beam B. Global beam C. Zone beam D. Hemispheric beam
Last Answer : B. Global 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 : How does spatial isolation technique in satellite communications avoid interference? A. Use of different polarity antennas B. Use of different types of antennas C. Employment of highly directional spot-beam antennas D. Use of low gain antennas
Last Answer : C. Employment of highly directional spot-beam antennas
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 : 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 : 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 : Best description of a collinear and broadside antenna radiation pattern. A. Bidirectional B. Perfect circle C. Unidirectional D. Omnidirectional
Last Answer : A. Bidirectional
Description : Footprint refers to coverage area in the globe A. Satellite radiation polarization B. Satellite navigation C. Satellite radiation pattern D. Satellite coverage
Last Answer : C. Satellite radiation pattern
Description : The earth area covered by a satellite radio beam. A. Beamwidth B. Bandwidth C. Footprint D. Zone
Last Answer : C. Footprint
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 : 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 : 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 : It is a measure of the microwave power radiated from an antenna as a function of angular direction from the antenna axis. A. Antenna pattern B. Polarization C. Beamwidth D. Sidelobes
Last Answer : C. Beamwidth
Description : A region in front of a paraboloid antenna. A. Transmission zone B. All of these C. Fraunhofer D. Fresnel
Last Answer : B. All of these
Description : What is the usual electrical length of a driven element in an HF beam antenna? A. ¼ wavelength B. ¾ wavelength C. ½ wavelength D. 1 wavelength
Last Answer : C. ½ wavelength
Description : The angle of elevation of the antenna beam is 20°. Calculate the transmission-path distance for an ionospheric transmission that utilizes a layer of virtual height 200 km. Use flat-earth approximation. A. 966 km B. 2100 km C. 1100 km D. 405 km
Last Answer : C. 1100 km
Description : Refers to a type of beam antenna which uses two or more straight elements arranged in line with each other. A. Dipole antenna B. Yagi antenna C. Whip antenna D. Rhombic antenna
Last Answer : B. Yagi antenna
Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications
Last Answer : B. FM Broadcasting
Description : What circuit is responsible in activating and deactivating adjacent antenna elements in a mobile satellite array? A. Radial divider B. Divider/combiner C. Radial combiner D. Radial multiplexer
Last Answer : A. Radial divider
Description : In a typical mobile satellite array antenna if three elements are activated, how many elements are deactivated? A. 3 B. 11 C. 5 D. 9
Last Answer : B. 11
Description : _________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency. A. Horn antenna B. LNA C. Satellite receiver D. Satellite dish
Last Answer : B. LNA
Description : Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT
Last Answer : B. Satellite dish
Description : A satellite transmitter operates at 4GHz with an antenna gain of 4dBi. The receiver 40000 km away has an antenna gain of 50 dBi. If the transmitter has a power of 8 W, find (ignoring feedline losses and mismatch) the EIRP in dBW. A. 50 B. 69 C. 49 D. 30
Last Answer : C. 49
Description : Type of antenna which is normally used for satellite tracking service. A. Omni B. Helical C. Yagi D. Dipole
Last Answer : B. Helical
Description : What do you call the single booster installed on the antenna dish of satellite receiver? A. Low noise amplifier B. Single amplifier C. Noise amplifier D. Rectifier
Last Answer : A. Low noise amplifier
Description : In shipboard satellite dish antennas system, azimuth is referred as the _______. A. 0 to 90 degrees B. Vertical aiming of the antenna C. North to East D. Horizontal aiming of the antenna
Last Answer : D. Horizontal aiming of the antenna
Description : A helical antenna is used for satellite tracking because of ______. A. Broad bandwidth B. Good front-to-back C. Maneuverability D. Circular polarization
Last Answer : D. Circular polarization
Description : Collects very weak signal from a broadcast satellite A. Satellite dish B. LNB C. Yagi-Uda antenna D. Satellite receiver
Last Answer : A. Satellite dish
Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator
Last Answer : D. To prevent re-radiation of the local oscillator
Description : Factors that determine the radiation resistance of an antenna A. Transmission line length and height of antenna B. The location of the antenna with respect to nearby objects C. It is a constant for all antennas since it is physical D. Sunspot activity and the time of day
Last Answer : B. The location of the antenna with respect to nearby objects
Description : An antenna efficiency is computed by using one of the following equations. A. Efficiency = (radiation resistance / transmission resistance) B. Efficiency = (total resistance / radiation resistance) x ... / transmitter output) x 100% D. Efficiency = (radiation resistance / total resistance) x 100%
Last Answer : D. Efficiency = (radiation resistance / total resistance) x 100%
Description : What is antenna bandwidth? A. Antenna length divided by the number of elements B. The angle between the half-power radiation points C. The angle formed between two imaginary lines drawn through D. The frequency range over which an antenna can be expected to operate satisfactorily
Last Answer : D. The frequency range over which an antenna can be expected to operate satisfactorily
Description : The advantage of using top loading in a shortened HF vertical antenna is A. lower quality factor B. greater structural strength C. higher losses D. improved radiation efficiency
Last Answer : D. improved radiation efficiency
Description : In order to get maximum radiation to all surrounding points in the horizontal plane, the antenna used is a A. vertical loop B. vertical quarter-wavelength rod C. array which includes parasitic elements D. a horizontal Hertz dipole
Last Answer : B. vertical quarter-wavelength rod
Description : A one-quarter wavelength shunt-fed vertical Marconi antenna A. has maximum radiation in a vertical direction B. must have a horizontal receiving antenna for the best reception C. must use a receiving antenna for the best reception D. must have a vertical receiving antenna for the best reception
Last Answer : D. must have a vertical receiving antenna for the best reception
Description : What is the radiation characteristic of a dipole antenna? A. Omnidirectional B. Bidirectional C. Unidirectional D. Hemispherical
Last Answer : B. Bidirectional
Description : What is included in the total resistance of an antenna system? A. Radiation resistance plus space impedance B. Radiation resistance plus transmission resistance C. Transmission line resistance plus radiation resistance D. Radiation resistance plus ohmic resistance
Last Answer : D. Radiation resistance plus ohmic resistance
Description : What is the term for the ration of the radiation resistance of an antenna to the total resistance of the system? A. Effective radiated power B. Beamwidth C. Radiation conversion loss D. Antenna efficiency
Last Answer : D. Antenna efficiency
Description : What is meant by the term radiation resistance for an antenna? A. The resistance in the trap coils to received signal B. An equivalent resistance that would dissipate the same amount of power as ... antenna C. The specific impedance of the antenna D. Losses in the antenna elements and feed line
Last Answer : B. An equivalent resistance that would dissipate the same amount of power as that radiated from an antenna
Description : What is meant by the term antenna bandwidth A. Antenna length divided by the number of elements. B. The angle between the half-power radiation points C. The frequency range over which and antenna ... perform well D. The angle formed between two imaginary line drawn through the ends of the elements
Last Answer : C. The frequency range over which and antenna can be expected to perform well
Description : What is meant by the term antenna efficiency? A. Efficiency = effective radiated power/transmitter output x 100% B. Efficiency = radiation resistance/ transmission resistance C. Efficiency = total resistance/radiation resistance x 100% D. Efficiency = radiation resistance/total resistance x 100%
Last Answer : D. Efficiency = radiation resistance/total resistance x 100%
Description : Radio wave concentration in the direction of the signal emitted by a directional antenna. A. Back lobe radiation B. Side lobe radiation C. Major lobe radiation D. Transmitted signal
Last Answer : C. Major lobe radiation
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 : ___________ 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
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 : How to maximize the skip distance? A. Using the smallest possible radiation angle and highest possible frequency B. Using the smallest possible radiation angle and lowest possible frequency ... highest possible frequency D. Using the biggest possible radiation angle and lowest possible frequency
Last Answer : A. Using the smallest possible radiation angle and highest possible frequency