HIGHLIGHTED-Microwave-Communications.pdf

Neighboring stations c shorten waveguide length d

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neighboring stations C. Shorten waveguide length D. Easy to install 130. What is the cut-off frequency of a waveguide?

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A. The highest frequency the waveguide operates B. The lowest frequency the waveguide operates C. The same as the operating frequency D. The only frequency the waveguide operates. 131. When the clearance above the obstruction is equal to the radii of even fresnel zones at the point of reflection. The RSL is A. Increased B. Decreased C. Constant D. Above threshold 132. What is the wavelength of a wave in a waveguide? A. Greater than in free space B. Depends only on the waveguide dimensions and the free-space wavelength C. Inversely proportional to the phase velocity D. Inversely proportional to the group velocity 133. The CCIR hypothetical reference circuit covering a distance of 25000 km consists of a total of how many hops? A. 5 B. 10 C. 24 D. 54 134. Water causes more attenuation particularly on what frequency? A. 20 GHz B. 63 GHz C. 183 GHz D. 202 GHz 135. At what frequency does oxygen cause excessive attenuation? A. 60 GHz B. 50 GHz C. 40 GHz D. 30 GHz 136. Which of the following is an atmospheric attenuation? A. Attenuation due to water vapor and oxygen B. Attenuation due to mist and fog C. Attenuation due to other gases D. Attenuation due to rain. 137. A microwave system operating at the 6 GHz band is carrying 600 voice channels. What is the noise loading power in dBmO? A. 12.78 B. 26.78 C. 27.78 D. 10.25 138. _________ is a microwave link between the down-town terminal and another out of town terminal. A. STL B. Uplink C. Downlink D. Terrestrial 139. Attenuator is used in the traveling wave tube to A. Prevent oscillation B. Increase gain C. Prevent saturation D. All of these 140. Is a method of diversity reception applied to reflective path to reduce fading. A. Frequency diversity B. Space diversity C. Polarization diversity D. Wavelength diversity 141. What is the effective earth’s radius used in communications design? A. 4000 miles B. K x 4000 miles C. 5000 miles D. K x 5280 miles
142. IF bandwidth of a radar system is inversely proportional to A. Pulse width B. Pulse interval C. Peak transmit power D. All of these 143. EADI stands for A. Electronic Air Data Indicator B. Electronic Altitude and Distance Indicator C. Electronic Altitude and Director Indicator D. Electronic Air and Distance Indicator 144. Which aircraft navigational system determines the time to station (TTS) or time to go (TTG)? A. ADF B. DME C. Timer D. ATC 145. What frequency does a radio altimeter operate? A. 33500 kHz B. 43000 kHz C. 33500 MHz D. 43500 MHz 146. What inflight system allows passengers to make telephone calls, send faxes, and computer data shop and play computer games, etc.?

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• Spring '17
• Jane Smooth
• d., microwave

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