Description : What frequency does oxygen causes excessive attenuation A. 119 GHz B. 183 GHz C. 310 GHz D. 60 GHz
Last Answer : D. 60 GHz
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
Description : What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)? A. 6.065 GHz B. 6.84 GHz C. 6.65 GHz D. 6.05 GHz
Last Answer : A. 6.065 GHz
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
Description : What is the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
Description : ECE Board Exam November 1996 What is the applied power if a thermal RF wattmeter is connected to a transmitter through a variable attenuator? The wattmeter reads 84 mW when 15 dB of attenuation is used. A. 4.656 watts B. 2.656 watts C. 3.656 watts D. 2.856 watts
Last Answer : B. 2.656 watts
Last Answer : A. PAM
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
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
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
Description : What limits the sensitivity of a receiver? A. The power supply of the receiver B. The power output of a transmitter C. The noise floor of the receiver D. The distance between the transmitter and receiver
Last Answer : C. The noise floor of the receiver
Description : What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5ft of the ground? A. 25 km B.25mi C. 70.73 km D. 70.73 mi
Last Answer : B.25mi
Description : Determine the terrain sensitivity loss for a 4-GHz carrier that is propagating over a very dry, mountainous area. A. -1.25 dB B. -3.05 dB C. -2.01 dB D. -5.01 dB
Last Answer : A. -1.25 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
Description : The frequency of Ku band for satellite communications. A. 6/4 GHz B. 14/11 GHz C. 12/14 GHz D. 4/8 GHz
Last Answer : B. 14/11 GHz
Description : Cable attenuation is usually expressed in terms of a. Loss per foot b. dB/km c. intensity per mile d. voltage drop per inch
Last Answer : b. dB/km
Description : The upper safe noise level for machine operator is: A. 85 db B.100db C. 110db D.115db
Last Answer : A. 85 d
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
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
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
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
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
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
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
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
Description : A coherent binary phase shift keyed BPSK transmitter operates at a bit rate of 20 Mbps with a carrier to noise ratio C/N of 8.8dB. Find Eb/No. A. 73 dB B. 62.4 dB C. 81.8 dB D. 8.8 dB
Last Answer : D. 8.8 dB
Description : The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi? A. 10.5 dB B. 34.5 dB C. 35 dB D. 20.5 dB
Last Answer : A. 10.5 dB
Description : Which noise figure represents the lowest noise in receiver? A. 1.6 dB B. 2.1 dB C. 2.7 dB D. 3.4 dB
Last Answer : A. 1.6 dB
Description : Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide. A. Space waves B. Terrestrial waves C. Mobile D. Hertzian waves
Last Answer : D. Hertzian waves
Description : The total propagation delay time from transmission to reception of signals from a ground transmitter to ground receiver with angle of elevation at 10 degrees respectively is A. 273 ms B. 239 ms C. 275 ms D. 260 ms
Last Answer : A. 273 ms
Description : What is the delay time for satellite transmissions from earth transmitter to earth receiver? A. 0.5 s B. 1s C. 5 ms D. 0.25 s
Last Answer : A. 0.5 s
Description : What is the delay time for satellite transmission from earth transmitter to earth receiver? A. 0.5 s B. 1.0 s C. 5 ms D. 0.25 ms
Description : Which of the following is not one of the natural ways a radio wave may travel from transmitter to receiver? A. Ground wave B. Micro wave C. Sky wave D. Space wave
Last Answer : B. Micro wave
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 : What is the device used in fiber optic communication which consist of a receiver transmitter use to clean up and amplify digital data moving in one direction and another in the opposite direction? A. Optic compressors B. Optic retarders C. Optic isolator D. Optic regenerators
Last Answer : D. Optic regenerators
Description : Who is responsible in the correctness and accuracy of transmitted information content over a data communication? A. The channel B. The transmitter and receiver C. The modem D. The bridge
Last Answer : B. The transmitter and receiver
Description : Main basic components of a data communication are composed of the following. A. Computer, modern and router B. Computer, bridge and gateway C. Transmitter, channel and receiver D. Transmitter, computer and modem
Last Answer : C. Transmitter, channel and receiver
Description : How can receiver desensitizing be reduced? A. Increase the receiver bandwidth B. Ensure good RF shielding between the transmitter and receiver C. Increase the transmitter audio gain D. Decrease the receiver squelch, gain.
Last Answer : D. Decrease the receiver squelch, gain.
Description : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator
Description : ______ is the first component of any MATV system to received broadcast signals. A. Receiver B. Antenna C. Filter D. Transmitter
Last Answer : B. Antenna
Description : Which of the following are uplinks in the Ku band? A. 14 to 14.5 GHz B. 11.7 to 12.2 GHz C. 14 to 15.5 GHz D. 11 to 11.5 GHz
Last Answer : A. 14 to 14.5 GHz
Description : The Ku-band in the satellite service A. 14/11 GHz B. 30/17 GHz C. 8/7 GHz D. 6/4 GHz
Last Answer : A. 14/11 GHz
Description : What is the approximate path loss from satellite-to-earth station? A. 100 dB B. 150 dB C. 175 dB D. 200 dB
Last Answer : D. 200 dB
Description : Most satellites operate in which frequency band? A. 30 to 300 MHz B. 300 MHz to 3 GHz C. 3 GHz to 30 GHz D. Above 300 GHz
Last Answer : C. 3 GHz to 30 GHz
Description : The bandwidth of C-band satellite frequency band in U.S. A. 500 GHz B. 1000 GHz C. 1000 MHz D. 500 MHz
Last Answer : D. 500 MHz
Description : What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz
Last Answer : C. 2225 MHz
Description : What is the frequency range of C-band? A. 8.5 to 12.5 GHz B. 3.4 to 6.425 GHz C. 12.95 to 14.95 GHz D. 27.5 to 31 GHz
Last Answer : B. 3.4 to 6.425 GHz
Description : Tropospheric scatter is a method of sky wave propagation for which of the following frequency bands? A. 300 kHz to 3 MHz B. 3 MHz to 30 MHz C. 30 MHz to 300 MHz D. 300 MHz to 3 GHz
Last Answer : D. 300 MHz to 3 GHz
Description : Which of the following frequency bands is best suited for sky wave propagation? A. 30 to 300 kHz B. 3 MHz to 30 MHz C. 30 MHz to 300 MHz D. 3 GHz to 30 GHz
Last Answer : B. 3 MHz to 30 MHz
Description : Which of the following is the uplink frequency in C-band? A. 5.925 GHz B. 4.2 GHz C. 7.425 GHz D. 3.7 GHz
Last Answer : A. 5.925 GHz