HIGHLIGHTED-Microwave-Communications.pdf

A waveguide assembly that lets the radar transmitter

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477. A waveguide assembly that lets the radar transmitter and receiver share an antenna is called a. Translator b. Diplexer c. Flip-flop d. duplexer 478. ________________ is a graph wherein the terrain in which the microwave beam should traverse. a. Topograph b. Radio path profile c. Fresnel graph d. Net path graph 479. The Fresnel zone is the circular zone about the _______ path. a. Reflected b. Direct c. Diffracted d. Refracted 480. The radius in the circular zone is in the first Fresnel zone when the reflected path is _______ longer than the direct path. a. λ/2 b. λ c. λ/4 d. λ/8 481. At __________ of the first Fresnel zone is a condition where there is no gain and no loss. a. 0.5 b. 0.6 c. 0.7 d. 0.8 482. The weakest signal the receiver could accept to be considered satisfactory. a. Threshold b. Fade margin c. RSL d. NPL 483. The frequency band from 8 to 12 GHz is known as the band. a. C b. Ku c. X d. Ka 484. The difference between the Received Signal Level and the FM Improvement Threshold a. System Gain b. Noise Threshold c. Fade Margin d. Reliability 485. A Fade Margin of 28 dB has a reliability of a. 99% b. 99.9% c. 99.99% d. 99.999% 486. Topographical maps are used for microwave communications systems design because _________ are shown, thereby elevations are known. a. Latitudes
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b. Longitudes c. Contour lines d. Scales 487. The dominant mode in a rectangular waveguide. a. TEM b. TE1,1 c. TE1,0 d. TM1,1 488. The velocity of a resultant wave as it travels through the waveguide. a. Speed of light b. Group velocity c. Phase velocity d. Incident velocity 489. The principal mode for a circular waveguide. a. TE1,0 b. TM2,0 c. TE1,1 d. TEM 490. A type of waveguide that reduces the cutoff wavelength, increases bandwidth and allows for a variation of the characteristics impedance. a. Ridge b. Rectangular c. Tee d. Twisted 491. The subscript which indicates the number of λ/2’ s along the waveguide height. a. m b. n c. a d. b 492. The international equivalent of the TE mode a. H b. E c. Z d. TEM 493. The smallest free space wavelength that is just unable to propagate in the waveguide under given conditions. a. Guide b. Phase c. Cut-off d. Group 494. The characteristic wave impedance of a waveguide in the TE mode is _______ that of the TM mode. a. Equal to b. Higher than c. Lower than d. NOTA 495. The following are methods of exciting waveguides except a. Slot coupling b. Antennas c. Flanges d. Direct coupling 496. Higher order mode-waveguides are not used in practice because they have ______ cut-off frequencies. a. Low b. High c. Indeterminate d. Fixed 497. Indicate which of the following cannot be followed by the word “waveguide” a. Elliptical b. Flexible c. Coaxial d. Ridged 498. A piston attenuator is a a. Vane attenuator b. Waveguide below cut-off c. Mode filter d. Flap attenuator
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499. Which of the following waveguide tuning components is not easily adjustable?
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  • Spring '17
  • Jane Smooth
  • d., microwave

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