Microwave Communications (Chapter 9: Past Board Excel)

ECE Board Exam April 2001
Which of the following will you avoid in the construction of a microwave station?
Long horizontal runs

ECE Board Exam November 2000
Radio frequency where waveguides are not used extensively.
150 MHz

ECE Board Exam April 2000
Term used to describe a process of approaching a desired point by directing the vehicle towards that point
Homing

ECE Board Exam November 1999
A system which does not refer to a technique in reducing the propagation errors in navigational system such as multipath effects
Pulse transmission

ECE Board Exam April 1999
Which of the following is a navigational equipment which utilizes a ground radar system to determine the position of a plane during its approach?
GCA

ECE Board Exam November 1998
_____________ is referred as the difference between available power and power budget.
Power margin

ECE Board Exam April 1998
Space diversity transmission means transmitting and receiving on __________.
two or more antennas operating on the same frequency

ECE Board Exam November 1996
One of the reasons why FDM is being replaced by TDM is
noise is amplified with voice when an FDM system is used

ECE Board Exam November 1996
What is the baseband frequency of standard FDM basic supergroup?
312 to 552 kHz

ECE Board Exam March 1996
The k-factor under normal atmospheric conditions in a microwave radio data profile calculation is equal to __________
4/3

ECE Board Exam March 1996
LORAN is  navigational system used primarily for _________
obtaining your fixed location over a large distances

ECE Board Exam April 2001
What navigational system technique uses an antenna directivity to reduce an undesired multipath signals?
LORAN-C

ECE Board Exam November 2000
In microwave frequencies, the LOS distance is something extended through the occurrence of ____________
ducting

ECE Board Exam April 2000
Which of the following if not a part of the navigational radar?
Duplexer
------------- part of navigational radar-----------
Pulser
Display unit
Synchronizer

ECE Board Exam November 1999
How do you account the effect of selective fading on the transmitted signal in terms of its bandwidth?
more affirmative at wider bandwidth

ECE Board Exam April 1999
Frequencies most affected by knife-edge refraction.
VHF and UHF

ECE Board Exam April 1998
Refers to an effect of selective fading.
A fading effect caused by phase difference between radio wave components of the same transmission, as experienced at the receiving station.

ECE Board Exam November 1996
When the clearance above the obstruction is equal to the radii of even Fresnel zones at the point of reflection the RSL
is decreased

ECE Board Exam March 1996
LORAN is a navigation system used primary for
obtaining fixes over large distances

ECE Board Exam November 1966
When the value of k increases, the effective result is _______ of the equivalent curvatures.
flattening

ECE Board Exam March 1996
TACAN is a navigational aid providing _________
bearing and distance indication

ECE Board Exam November 1996
If Ns = 250 determine the earth radius k-factor.


ECE Board Exam March 1996
A one-hop, full duplex, microwave system is in a space diversity arrangement. Determine how many receivers in all are used?
2

ECE Board Exam November 1996
A microwave communications system space loss calculation formula is
92.4 + 20 log F + 20 log D

ECE Board Exam March 1996
Radio fading resulting from obstruction losses.
Log normal fading

ECE Board Exam April 1998
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.
Circulator

ECE Board Exam November 1996
What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path?
Frequency

ECE Board Exam November 1996
What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz?


ECE Board Exam November 1996
Low-power radar uses
IMPATT

ECE Board Exam November 2000
A component of a microwave station that samples signal traveling in one direction down to the transmission line.
Directional coupler

ECE Board Exam April 2000
A navigational error which is caused by reflection of obstruction close to the location of navigational aid having a normal concern on directional bearing.
Site error

ECE Board Exam April 1999
An aircraft deviation  measured by an ILS localizer.
Horizontal

ECE Board Exam April 1998
Which of the following systems is not used in radio detection and ranging?
Amplitude modulation

----------- systems used in radio detection and ranging----------
Frequency shift
Frequency modulation
Pulse radar

ECE Board Exam April 1997
A microwave system that requires the use of repeater.
Intervening system that requires the use of repeater.
Distances involved are greater

 ECE Board Exam November 1996
Space diversity transmission means transmitting and receiving on
two or more antennas operating on the same frequencies

ECE Board Exam April 1997
RADAR means
Radio Detection and Ranging

ECE Board Exam November 2000
Which band in the radio spectrum does the radio navigational system Omega transmit?
VLF

ECE Board Exam November 1998
Which of the following is not a common microwave application?
Mobile radio

------------- common microwave application --------------
Radar
Data transmission
Space communications

ECE Board Exam April 1998
What do you call a circuit that controls the magnetron output?
Modulator

ECE Board Exam April 1997
A microwave link between the earth station and the down-town terminal
Terrestrial link

ECE Board Exam November 1997
Two or more antennas separated by 9 wavelengths are used.
Space diversity

ECE Board Exam April 2000
In radio navigation, one of the following deviations of an airplane is determined by an ILS localizer.
Horizontal

ECE Board Exam April 1997
The advantage of periscope antenna in microwave.
Shorten waveguide link

ECE Board Exam April 2000
In navigational system, one of the following indication is provided by the localizer unit of the ILS.
A horizontal deviation of an airpalne from its optimum path of descent along the axis of the runway.

ECE Board Exam April 1999
Referred to as the cycle time difference between the master and the slave signals to reach the receiver in the operation of loran navigational equipment.
Time delay

ECE Board Exam April 1999
Which of the HF marine antenna safety link is intended to be broken during the unusual movement of the ship?
Weak part

ECE Board Exam April 1999
What is being measured in radar theory to complete the determination of a distance to a target or object, after a high radio frequency signal is transmitted to a target?
Echo time off the object to the source