HIGHLIGHTED-Microwave-Communications.pdf

Calculate the cutoff frequency a 35 ghz b 15 ghz c 75

Info icon This preview shows pages 25–27. Sign up to view the full content.

View Full Document Right Arrow Icon
Calculate the cutoff frequency a) 3.5 GHz b) 15 GHz c) 7.5 GHz d) 4 GHz 281. The main difference between the operation of transmission liners and waveguides is that a) the latter is not distributed, like transmission lines b) the former can use stubs and quarter-wave transformers, unlike the latter c) transmission lines use the principal mode of propagation, and therefore do not suffer from low-frequency cut-off d) terms such as impedance matching and standing-wave ratio cannot be applied to waveguides 282. The useful power of the transmitter that is contained in the radiated pulses is termed as ______. a) rms power b) rated power c) peak power d) average power 283. In radars, echoes that are produced when the reflected beam is strong enough to make a second trip a) double range echoes b) double frequencies echoes c) second return echoes d) second time around echoes 284. Indicate the false statement. Compared with equivalent transmission lines, 3 GHz waveguides a) are less lossy b) can carry higher powers c) are less bulky d) have lower attenuation 285. The range beyond which targets appear as second return echoes is called a) maximum range b) maximum unambiguous range c) maximum usable range d) any of these 286. When a particular mode is excited in a waveguide, there appears an extra electric component, in the direction of propagation. The resulting mode is a) transverse electric b) transverse magnetic c) longitudinal d) transverse-electromagnetic 287. In radars, echoes that arrive after the transmission of the next pulse are called _____. a) second return echoes b) second time around echoes c) multiple time around echoes d) any of these 288. When electromagnetic waves are reflected at an angle from a wall, their wavelength along the wall is a) the same as the free space
Image of page 25

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
b) the same as the wavelength perpendicular to the wall c) shortened because of the Doppler effect d) greater than in the actual direction of propagation 289. A radar mile is equivalent to a) 2000 mi b) 2000 m c) 2000 yd d) 2000 km 290. As a result of reflections from a plane conducting wall, electromagnetic waves acquire an apparent velocity of light in space a) velocity of propagation b) normal velocity c) group velocity d) phase velocity 291. In radars, the time between pulses is called ______. a) rest time b) duration time c) delay time d) propagation time 292. Indicate the false statement. When the free- space wavelength of a signal equals the cutoff wavelength of the guide a) the group velocity of the signal becomes zero b) the phase velocity of the signal becomes infinite c) the characteristic impedance of the guide becomes infinite d) the wavelength within the waveguide becomes infinite 293. In radars, the duration of the pulse is a) duty cycle b) pulse width c) pulse amplitude d) pulse cycle 294. A signal propagated in a waveguide has a full wave electric intensity change between two further
Image of page 26
Image of page 27
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern