Description : What device can be constructed to allow microwave energy to pass in one direction but blocks energy in the other direction in a waveguide?
Last Answer : errite Isolato
Description : When microwave energy is passed through a piece of ferrite in a magnetic field, another effect occurs. If the frequency of the microwave energy is much greater than the electron wobble frequency, the plane of polarization of the wavefront is rotated. This is known as
Last Answer : Faraday Rotation Effect
Description : To avoid objectionable noise in a microwave TV link, the SNR should be about:
Last Answer : 25 or more
Description : The upper pulse rate and information carrying capacity of a cable is limited by:
Last Answer : modal dispersion
Description : Sixteen different levels (symbols) are used to encode binary data. The channel bandwidth is 36 MHz. The maximum channel capacity is
Last Answer : 288 Mbps
Description : An FDM hierarchy which is formed by frequency – division multiplexing 10 super groups together for a combined capacity of 600 voice band message channels.
Last Answer : Mastergroup
Description : A theory that establishes the minimum sampling rate that can be used for a given PCM systems.
Last Answer : Nyquist sampling theorem
Description : A theory that establishes the minimum sampling rate that can be used for a given PCM systems
Description : What distinguishes digital radio systems from conventional analog communications system?
Last Answer : the nature of the modulating signal
Description : In communication systems the frequency range used for voice is:
Last Answer : 300 Hz to 3800 Hz
Description : The most common method used for sampling voice signals in PCM systems.
Last Answer : flat top sampling
Description : FDM telephone systems accommodate many channels by:
Last Answer : Using multiple levels of multiplexing
Description : means to prove the identity of the entity that tries to access the system's resources.
Last Answer : Entity authentication
Description : Emphasizing low-level signals and compressing higher level signals is called:
Last Answer : companding
Description : Low-Earth-orbit (LEO) satellites have _____ orbits.
Last Answer : polar
Description : What is the spectrum range of U600 mastergroup? A. 60 – 108 kHz B. 564 – 3084 kHz C. 312 – 552 kHz D. 60 -2788 kHz
Last Answer : B. 564 – 3084 kHz
Description : A special type of transmission line that consist of conducting metallic tube through which high frequency electromagnetic energy is propagated
Last Answer : waveguide
Description : Which type of fiber-optic cable is the most widely used?
Last Answer : multimode step-index
Description : Which type of fiber-optic cable has the least modal dispersion?
Last Answer : single-mode step index
Description : With which emission type is the capture effect more pronounced?
Last Answer : FM
Description : Type of bend that occurs as a result of differences in thermal contraction rates between the core and the cladding material.
Last Answer : Microbending
Description : Type of PCM which is designed to take advantage of the sample-to-sample redundancies in the typical speech waveform
Last Answer : Differential PCM
Description : ____ is a virtual-circuit wide-area network that was designed in response to demands for a new type of WAN in the late 1980s and early 1990s.
Last Answer : . Frame Relay
Description : The magnetic field of an antenna is perpendicular to the earth. The antenna’s polarization ___
Last Answer : is horizontal
Description : It is the ratio of the power density radiated in a particular direction to the power density radiated to the same point by a reference antenna, assuming both antennas are radiating the same amount of power
Last Answer : directive gain
Description : The property of interchangeability for the transmitting and receiving operations is known as ____
Last Answer : reciprocity
Description : The fields surrounding the antenna do not collapse their energy back into the antenna but rather radiate it out in space
Last Answer : radiation field
Description : It is the ratio of the radiated to the reflected energy:
Last Answer : Radiation efficiency
Description : It is the resistance that, if it replaced the antenna, would dissipate exactly the same amount of power that the antenna radiates
Last Answer : . Radiation resistance
Description : Plots of field strength or power density with respect to the value at a reference point.
Last Answer : relative radiation pattern
Description : The radiation pattern plotted in terms of electric field strength or power density
Last Answer : absolute radiation pattern
Description : The line bisecting the major lobe, or pointing from the center of the antenna in the direction of maximum radiation is called _____
Last Answer : line of shoot
Description : If energy is applied at the geometrical center of antenna, the antenna is said to be ___
Last Answer : center-fed
Description : The radiation pattern of collinear and a broadside antenna is __
Last Answer : bidirectional
Description : Hertz antenna are predominantly used with frequencies above
Last Answer : 2MHz
Description : The point on the antenna where the transmission line is connected is called _____
Last Answer : feedpoint
Description : The discone antenna is
Last Answer : useful as a UHF receiving antenna
Description : It is the same with directive gain except that the total power fed to the antenna is used and the antenna efficiency is taken into account.
Last Answer : power gain
Description : ____ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer.
Last Answer : UDP
Description : ______ are special-interest groups that quickly test, evaluate, and standardize new technologies
Last Answer : Forums
Description : _______ refers to the structure or format of the data, meaning the order in which they are presented.
Last Answer : Semantics
Description : ________ defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation.
Last Answer : syntax
Description : The effect of a large magnitude of the numerical aperture.
Last Answer : The amount of external light the fiber will accept is greater
Description : It is the figure of merit used to measure the magnitude of the acceptance angle.
Last Answer : numerical aperture
Description : It is a result of photons of light that are absorbed by the atoms of the glass core molecule
Last Answer : infrared absorption
Description : It is caused by valence electrons in the silica material from which the fiber are manufactured.
Last Answer : ultraviolet absorption
Description : It is analogous to power dissipation to copper cables, impurities in the fiber absorb the light and covert it to heaT
Last Answer : absorption loss
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber.
Last Answer : Acceptance cone half-angle
Description : Laser light is very bright because it is:
Last Answer : coherent
Description : The process of moving from one energy level to another is called __
Last Answer : Absorption