Download Radar Systems: Fundamentals and Applications - Exam Questions and Answers and more Exams Electrical Engineering in PDF only on Docsity!
ATT VERIFIED EXAM TEST
what antenna do you use to determine the bearing of an object in a radar system? - ✔ ✔ narrow horizontal beam width a truncated parabolic antenna is normally used in a _____________ - ✔ ✔ radar microwave systems what does adding a reflector to a horn antenna do? - ✔ ✔ increases power and directivity what is the physical handling and installation of a waveguide called? - ✔ ✔ pluming a wave guide is a system that is capable of guiding ___________ - ✔ ✔ electromagnetic energy how is electromagnetic energy produced? - ✔ ✔ current flowing through a conductor the width of the waveguide is the ____ dimension - ✔ ✔ "a" the height of the waveguide is the ____ dimension - ✔ ✔ "b" what does the "a" dimension of a waveguide determine? - ✔ ✔ the frequency range that the waveguide can handle what does the "b" dimension of a waveguide determine? - ✔ ✔ the power handling capacity of the waveguide what are the two basic types of energy transmission? - ✔ ✔ pulse and continuous wave (cw)
modulation insures that the transmitter operates the correct _____ and ______ - ✔ ✔ pulse repetition frequency and pulse width what is prf? - ✔ ✔ pulse repetition frequency what is pw? - ✔ ✔ pulse width what losses are associated with transmission lines? - ✔ ✔ resistive, capacitive, and inductance what loss is due to resistance, especially in long lines? - ✔ ✔ copper loss what loss is due to the high frequency current flowing near the outer surface of the conductor? - ✔ ✔ skin effect what loss is due to the capacitance formed between transmission lines?
- ✔ ✔ dielectric loss leakage what loss is due to the portion of electrical energy lost to the atmosphere? - ✔ ✔ radiation loss what loss is due to the expanding and collapsing of magnetic fields? - ✔ ✔ induction loss characteristic ___________ is distributed inductance and capacitance of the line - ✔ ✔ impedance what is the most commonly used reference level in the decibel measurement system for radar? - ✔ ✔ 1 miliwatt what happens to the frequency of a cw radar rf if it reflects of an outbound object? - ✔ ✔ decreases
when is the element in the telltale oil filter changed? - ✔ ✔ just before the red element indicator reaches the red line which system provides the initial source of cooling water? - ✔ ✔ primary system what system transfers the heat load from the electric equipment? - ✔ ✔ secondary system why are some equipment enclosures hermatically sealed? - ✔ ✔ moisture what is the least efficient type of equipment cooling? - ✔ ✔ convection what are the two major categories of ecm? - ✔ ✔ denial and deception what are the sub categories of ecm? - ✔ ✔ active/passive deception & active/passive denial what is active ecm also referred to as? - ✔ ✔ jamming what does cw mean? - ✔ ✔ continuous wave what ecm transmits constant amplitude, constant frequency, and unmodulated jamming signal to change the signal-to-noise ratio of a radar receiver? - ✔ ✔ cw jammer what jammer generates rf noise in a particular band or frequency channel to change the signal-to-noise ratio of a radar receiver? - ✔ ✔ spot noise what is eccm? - ✔ ✔ electronic counter-counter measures
what method is used to combat ecm? - ✔ ✔ eccm what are the characteristics of an antenna? - ✔ ✔ efficiency, directivity, and reciprocity how is an antennas power gain measured? - ✔ ✔ reference antenna what is the ability of an antenna to direct most of its power in a concentrated area? - ✔ ✔ directivity what kind of antennas radiate or recieve in all directions? - ✔ ✔ omnidirectional what is the ability of an antenna to act as either a transmitter or reciever? - ✔ ✔ reciprocity what is the doppler shift of a stationary object? - ✔ ✔ none two objects at the same range must be seperated by at least _____ beam width to be separately distinguishable by the radar system - ✔ ✔ one what does the rate at which a modulator tuns on and off determine? - ✔ ✔ prf what does the rf energy reflected from an object provide to the radar system? - ✔ ✔ bearing, range, elevation, and velocity what does radar stand for? - ✔ ✔ radio detection and ranging what are fiber optic systems capable of transmitting? - ✔ ✔ digital and analog signals
what kind of loss is due to an imperfection of the core-cladding boundary? - ✔ ✔ microbend what do you need to transfer a large amount of information at a higher bit rate with more noise per cable? - ✔ ✔ wider bandwidth what kind of optical fiber allows only one light path? - ✔ ✔ single what kind of optical fiber is made of several converting layers of material? - ✔ ✔ multimode graded index what are the characteristics of optical power? - ✔ ✔ wavelength, specteral width, numerical aperature, response time, and output power what are the characteristics of an optical detector? - ✔ ✔ responsivity, response time, numerical aperature, quantum efficiency, and dark current what happens to the resistance of a photocell when the applied intensity decreases? - ✔ ✔ increases what section is responisble for converting light energy to an electrical output signal? - ✔ ✔ reciever section what is the name of the central core for a fiber optic cable? - ✔ ✔ waveguide what section carries the light signal to the receiver section? - ✔ ✔ transmission section (cable) what is the most commonly used optical light source for a fiber optic? - ✔ ✔ led
what light source provides a condensed beam with a narrow spectral range? - ✔ ✔ laser what section is responsible for taking electrical input signals and converting them to light energy? - ✔ ✔ transmitter section what is light composed of? - ✔ ✔ photons
