How does the gain of a parabolic dish type antenna change when the operating frequency is doubled? A. Gain does not change B. Gain is multiplied by 0.707 C. Gain increases 6 dB D. Gain increases 3 dB

How does the gain of a parabolic dish type antenna change when the operating frequency is
doubled?
A. Gain does not change
B. Gain is multiplied by 0.707
C. Gain increases 6 dB
D. Gain increases 3 dB
by

1 Answer

Answer :

C. Gain increases 6 dB
by

Related questions

Determine the gain of a 6 ft. parabolic dish operating at 1800 MHz. A. 30 dB B. 11.2 dB C. 15.5 dB D. 28.17 dB

Description : Determine the gain of a 6 ft. parabolic dish operating at 1800 MHz. A. 30 dB B. 11.2 dB C. 15.5 dB D. 28.17 dB

Last Answer : D. 28.17 dB

An antenna with very high gain and very narrow beamwidth. A. Helical antenna B. Discone antenna C. Horn antenna D. Parabolic dish antenna

Description : An antenna with very high gain and very narrow beamwidth. A. Helical antenna B. Discone antenna C. Horn antenna D. Parabolic dish antenna

Last Answer : D. Parabolic dish antenna

Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW

Description : Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW

Last Answer : A. 0.871 μW

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

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

If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times

Description : If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times

Last Answer : B. 1000 times

If the antenna current is doubled, the field strength at a particular position is A. doubled B. halved C. multiplied by a factor of four D. divided by a factor of four

Description : If the antenna current is doubled, the field strength at a particular position is A. doubled B. halved C. multiplied by a factor of four D. divided by a factor of four

Last Answer : A. doubled

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

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

What illumination factor is normally considered in computing parabolic antenna gain in microwave communications? A. 0.54 B. 0.65 C. 0.75 D. 0.85

Description : What illumination factor is normally considered in computing parabolic antenna gain in microwave communications? A. 0.54 B. 0.65 C. 0.75 D. 0.85

Last Answer : A. 0.54

A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW. What is the gain in dB, obtained by the use if the reflector. (Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24

Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24

Last Answer : B. 2.6

What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W

Description : What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W

Last Answer : C. 60 W

What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W

Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W

Last Answer : A. 37.6 W

What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W

Description : What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W

Last Answer : B. 39.7 W

Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances. A. 10 dB B. 6 dB C. 3 dB D. 8 dB

Description : Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances. A. 10 dB B. 6 dB C. 3 dB D. 8 dB

Last Answer : B. 6 dB

A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 kW. What is the gain in dB obtain by the use of the reflector ? ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6

Description : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6

Last Answer : D. 2.6

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

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

Gain of an isotropic antenna A. -1 dB B. 1 dB C. 0 dB D. 2 dB

Description : Gain of an isotropic antenna A. -1 dB B. 1 dB C. 0 dB D. 2 dB

Last Answer : C. 0 dB

What is the gain, in dB of a helical antenna with diameter of λ/3, 10 turns at pitch of λ/4, used at 100 MHz? A. 16 B. 41.1 C. 31.4 D. 1.25

Description : What is the gain, in dB of a helical antenna with diameter of λ/3, 10 turns at pitch of λ/4, used at 100 MHz? A. 16 B. 41.1 C. 31.4 D. 1.25

Last Answer : A. 16

The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts

Description : The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts

Last Answer : B. 158 watts

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

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

What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W

Description : What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W

Last Answer : A. 317 W

What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W

Description : What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W

Last Answer : B. 126 W

What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W

Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W

Last Answer : D. 150 W

What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W

Description : What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W

Last Answer : C. 31.5 W

_________ 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

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

A Hertz antenna is operating on a frequency of 2182 kHz and consists of a horizontal wire that is hanged between two towers. What is the frequency of its third harmonic? A. 727 kHz B. 6546 kHz C. 436 kHz D. 6.546 kHz

Description : A Hertz antenna is operating on a frequency of 2182 kHz and consists of a horizontal wire that is hanged between two towers. What is the frequency of its third harmonic? A. 727 kHz B. 6546 kHz C. 436 kHz D. 6.546 kHz

Last Answer : B. 6546 kHz

ECE Board Exam March 1996 A type of an underground antenna is a/an __________ antenna. A. Hertz B. isotropic C. parabolic D. Marconi

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

If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts

Description : If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts

Last Answer : D. 6 watts

When a capacitor is connected in series with a Marconi antenna? A. Antenna open circuit stops transmission B. An inductor of equal value must be added C. No change occurs to antenna D. Antenna resonant frequency increases

Description : When a capacitor is connected in series with a Marconi antenna? A. Antenna open circuit stops transmission B. An inductor of equal value must be added C. No change occurs to antenna D. Antenna resonant frequency increases

Last Answer : D. Antenna resonant frequency increases

What happens to the beamwidth of an antenna as the gain is increased? A. The beamwidth increases geometrically as the gain is increased. B. The beamwidth increases arithmetically as the gain is increased. C. The beamwidth is essentially unaffected by the gain of the antenna. D. The beamwidth decreases as the gain is increased.

Description : What happens to the beamwidth of an antenna as the gain is increased? A. The beamwidth increases geometrically as the gain is increased. B. The beamwidth increases arithmetically as the gain is increased ... unaffected by the gain of the antenna. D. The beamwidth decreases as the gain is increased.

Last Answer : D. The beamwidth decreases as the gain is increased.

A parabolic dish antenna isa(n)_______ antenna. A) omnidirectional B) bidirectional C) unidirectional D) horn

Description : A parabolic dish antenna isa(n)_______ antenna. A) omnidirectional B) bidirectional C) unidirectional D) horn

Last Answer : unidirectiona

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. 

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

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

ECE Board Exam March 1996 The capture area of an antenna is directly proportional to the A. frequency of the received signal B. distance between transmitter and receiver C. gain of the antenna D. power density of the signal

Description : ECE Board Exam March 1996 The capture area of an antenna is directly proportional to the A. frequency of the received signal B. distance between transmitter and receiver C. gain of the antenna D. power density of the signal

Last Answer : C. gain of the antenna

One of the following is very useful as a multiband HF receiving antenna. A. Parabolic antenna B. Elementary doublet C. Log-periodic D. Square loop

Description : One of the following is very useful as a multiband HF receiving antenna. A. Parabolic antenna B. Elementary doublet C. Log-periodic D. Square loop

Last Answer : C. Log-periodic

A special horn antenna consisting of a parabolic cylinder joined to a pyramidal horn. A. Hoghorn B. Cass-horn C. Pyramidal horn D. Conical horn

Description : A special horn antenna consisting of a parabolic cylinder joined to a pyramidal horn. A. Hoghorn B. Cass-horn C. Pyramidal horn D. Conical horn

Last Answer : A. Hoghorn

What antenna can be used to minimize the effect of Faraday rotation of polarization? A. Dipole B. Parabolic C. Helical D. Rhombic

Description : What antenna can be used to minimize the effect of Faraday rotation of polarization? A. Dipole B. Parabolic C. Helical D. Rhombic

Last Answer : C. Helical

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

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

It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation, taken under the normal operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power

Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power

Last Answer : C. Mean power

The antenna current is doubled when the modulation index is doubled in ______ AM system. A. A5C B. A3J C. A3 D. A3H

Description : The antenna current is doubled when the modulation index is doubled in ______ AM system. A. A5C B. A3J C. A3 D. A3H

Last Answer : B. A3J

If the modulation index of an AM wave is doubled, the antenna current is also doubled, the AM system being used is A. A5C B. A3J C. A3H D. A3

Description : If the modulation index of an AM wave is doubled, the antenna current is also doubled, the AM system being used is A. A5C B. A3J C. A3H D. A3

Last Answer : B. A3J

What is the theoretical gain of a Hertzian dipole? A. 1.76 dB B. 2.15 dB C. 3 dB D. 0 dB

Description : What is the theoretical gain of a Hertzian dipole? A. 1.76 dB B. 2.15 dB C. 3 dB D. 0 dB

Last Answer : A. 1.76 dB

Theoretical gain of a hertzian dipole A. 0 dB B. 1.76 dB C. 3 dB D. 2.15 dB

Description : Theoretical gain of a hertzian dipole A. 0 dB B. 1.76 dB C. 3 dB D. 2.15 dB

Last Answer : B. 1.76 dB

What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB

Description : What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB

Last Answer : B. 10 dB

What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz? A. 198 dB B. 202 dB C. 142 dB D. 138 dB

Description : What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz? A. 198 dB B. 202 dB C. 142 dB D. 138 dB

Last Answer : A. 198 dB

Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT

Description : Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT

Last Answer : B. Satellite dish

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

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

Collects very weak signal from a broadcast satellite A. Satellite dish B. LNB C. Yagi-Uda antenna D. Satellite receiver

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

The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB

Description : The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB

Last Answer : A. 403 dB

The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB

Description : The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB

Last Answer : C. 10.79 dB

If you have available number of power amplifiers with a gain of 100 each, how many such amplifiers do you need to cascade to give an overall gain of 60 dB? A. 3 B. 4 C. 5 D. 2

Description : If you have available number of power amplifiers with a gain of 100 each, how many such amplifiers do you need to cascade to give an overall gain of 60 dB? A. 3 B. 4 C. 5 D. 2

Last Answer : A. 3