Description : Space diversity transmission means transmitting and receiving on _______. A. Two or more antennas operating on two different frequencies B. Two or more identical frequencies C. Two or more antennas operating on the same frequency D. Two or more different frequency
Last Answer : C. Two or more antennas operating on the same frequency
Description : Space diversity transmission means transmitting and receiving on A. two or more antennas operating on two different frequencies B. two or more identical frequencies C. two or more different frequencies D. two or more antennas operating on the same frequencies
Last Answer : D. two or more antennas operating on the same frequencies
Description : When antennas are closed to the ground, _______ polarization is ideal A. horizontally polarized B. vertically polarized C. circularly polarized D. both A and B
Last Answer : B. vertically polarized
Description : In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF
Last Answer : A. VHF, UHF
Description : What is the gain of four identically polarized antennas stacked one above the other and fed in phase? A. 3 dB over the gain of one antenna B. 10 dB over the gain of one antenna C. 4 dB over the gain of one antenna D. 6 dB over the gain of one antenna
Last Answer : D. 6 dB over the gain of one antenna
Description : The best solution to fading is _____. A. space diversity B. frequency diversity C. polarization diversity D. wavelength diversity
Last Answer : A. space diversity
Description : What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path? A. Quadruple B. Frequency C. Polarization D. Space
Last Answer : B. Frequency
Description : The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these
Last Answer : C. increase the antenna’s power gain
Description : What is the effect of adding a capacitor in series with an antenna? A. The antenna’s resonant frequency will increase B. The antenna’s resonant frequency will decrease C. The antenna will be physically 5% longer than its electrical length D. A capacitor is never added in series with an antenna
Last Answer : A. The antenna’s resonant frequency will increase
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 free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz? A. 145.6 dB B. 138.5 dB C. 135.5 dB D. 140.89 dB
Last Answer : D. 140.89 dB
Description : ECE Board Exam March 1996 When the transmitting and receiving antennas are in line-of-sight of each other, the mode of propagation is ________ wave. A. space or direct B. ground C. surface D. sky
Last Answer : A. space or direct
Description : A one-hop, full duplex, microwave system in a space diversity arrangement. Determine “how many receivers in all are used?” A. 8 B. 2 C. 4 D. 6
Last Answer : B. 2
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 : An ungrounded antenna near the ground A. acts as a single antenna of twice the height B. is unlikely to need an earth mat C. acts as antenna array D. must be horizontally polarized
Last Answer : C. acts as antenna array
Description : The antenna radiates _____ polarized waves when the transmitter antenna is horizontally installed. A. Vertically B. negatively C. horizontally D. circularly
Last Answer : C. horizontally
Description : Discone radiation pattern is ______. A. omnidirectional/vertical polarized B. unidirectional C. bidirectional D. figure of eight
Last Answer : A. omnidirectional/vertical polarized
Description : A horizontal antenna is _____. A. vertically polarized B. horizontally polarized C. centrally polarized D. circularly polarized
Last Answer : B. horizontally polarized
Description : What is a device that detects both vertically and horizontally polarized signals simultaneously? A. Orthomode transducer B. Crystal detector C. Optoisolator D. Isomode detector
Last Answer : A. Orthomode transducer
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth. B. The magnetic field is parallel to the earth. C. Both the electric and magnetic fields are horizontal D. Both the electric and magnetic fields are vertical
Last Answer : A. The electric field is parallel to the earth.
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth B. Both the electric and magnetic fields are vertical C. Both the electric and magnetic fields are horizontal D. The magnetic fields is parallel to the earth
Last Answer : A. The electric field is parallel to the earth
Description : Known as the satellite transmitted signal form a satellite transponder to earth’s station. A. Uplink B. Down link C. RHCP D. Vertically polarized
Last Answer : B. Down link
Description : An electromagnetic wave is ________ polarized when the electric field lies wholly in one plane containing the direction of propagation. A. Horizontally B. Linearly C. Circularly D. Vertically
Last Answer : B. Linearly
Description : ______ is a device that detects both vertically and horizontally polarized signals simultaneously. A. Crystal B. Orthomode transducer C. Light transducer D. Optoisolator
Last Answer : B. Orthomode transducer
Description : A horizontal antenna is A. centrally polarized B. vertically polarized C. horizontally polarized D. perpendicularly polarized
Last Answer : C. horizontally polarized
Description : Satellite signal transmitted from a satellite transponder to earth’s station. A. Vertically polarized B. Uplink C. Downlink D. RHCP
Last Answer : C. Downlink
Description : Indicate which of the following reasons for using metal counterpoise with antennas is false. A. Impossibly of a good ground connection B. Protection of personnel working underneath C. Provision of an earth for the antenna D. Rockiness of the ground itself
Last Answer : B. Protection of personnel working underneath
Description : Which of the following antennas is best excited from a waveguide? A. Biconical B. Horn C. Helical D. Discone
Last Answer : B. Horn
Description : Good grounding is important for A. horizontal antennas B. broadside array antennas C. vertical antennas D. Yagi-Uda antennas
Last Answer : C. vertical antennas
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 : 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 : Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long
Last Answer : D. A vertical antenna which is a quarter-wavelength long
Description : How will you increase the gain of an antenna? A. By adding several antennas in parallel B. By focusing the radiated energy in one desired direction C. By making antenna rods thicker D. By making the antenna size larger
Last Answer : B. By focusing the radiated energy in one desired direction
Description : All elements in a beam _____ antennas are in line A. collinear B. yagi C. broadside array D. log-periodic
Last Answer : A. collinear
Description : When speaking of antennas. ______ is a section which would be a complete antenna by itself. A. image B. top loading C. bay D. quarterwave
Last Answer : C. bay
Description : The radiation patterns of earth coverage antennas have a beamwidth of approxiamately A. 21˚ B. 5˚ C. 17˚ D. 35˚
Last Answer : C. 17˚
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 : Which of the following antennas receives signals equally well from all directions in a horizontal plane? A. Hetz antenna B. Vertical Marconi antenna C. Yagi antenna D. Helical antenna
Last Answer : B. Vertical Marconi antenna
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 : 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 : 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 : 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 : 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 : Is the width of the range of wavelengths emitted by the light source a. Bandwidth b. Chromatic Dispersion c. Spectral width d. Beamwidth
Last Answer : c. Spectral width
Description : The band of light wavelengths that are too long to be seen by the human eye a. Amber b. Visible c. Infrared d. Ultraviolet
Last Answer : c. Infrared
Description : _____ is an antenna made up of a number of full wavelengths A. Elementary doublet B. Log-periodic C. Long wire D. Whip
Last Answer : C. Long wire
Description : What are the electromagnetic radiations of wavelengths less than 300 angstroms? A. X-rays B. Ultraviolet rays C. Infrared D. Microwaves
Last Answer : A. X-rays
Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 cm and 1.7 mm B. 5 mm and 2.5 mm C. 5 cm and 2.5 cm D. 1.35 mm and 1.7 μm
Last Answer : B. 5 mm and 2.5 mm
Description : Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5 mm C. 1.35 dm and 1.7 cm D. 1.5 cm and 5mm
Last Answer : A. 1.35 cm and 1.7 mm
Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 mm and 1.7 μm B. 1.35 cm and 1.7 mm C. 5 cm and 2.5 cm D. 5 mm and 2.5 mm
Last Answer : D. 5 mm and 2.5 mm