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Frequency-Agile Antennas for Wireless Communications |
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Click here for the complete list of RF Cafe Quizzes. Note: Some material based on books have quoted passages.
Graciously provided by Artech House
1. To which class of antennas do frequency agile antennas (FAAs) belong? a) Federal aviation antennas (FAAs) b) Passive integrated antennas (PIAs) c) Active integrated antennas (AIAs) d) Cross-Influenced Antennas (CIAs) 2. How does antenna gain differ from antenna directivity? a) There is no difference b) Gain only applies to active antennas c) Gain can only be positive whereas directivity can be negative d) Gain accounts for losses as well as directivity 3. What are the two types of tuning used in FAAs? a) Discrete and continuous b) High power and low power c) Manual and automatic d) Electronic and mechanical 4. When did microstrip antennas start coming into common use? a) In the 1920s b) In the 1950s c) In the 1970s d) In the 1990s 5. For which microstrip patch antenna formats does Frequency-Agile Antennas for Wireless Communications provide field equations? a) Rectangular, dipole, circular, and annular (ring) b) Spherical and tesseractical c) Cubical and spherical d) Tesseractical and cubical 6. What type of tuning is typically available for antennas? a) Changing one or more physical dimensions b) Altering material properties c) Switching and/or tunable electronics d) All the above 7. How can the permittivity of ferroelectric substrates be altered? a) By applying a mechanical stress b) By applying an electric field c) By harmonic inversion d) By optical manipulation 8. What methods of mechanical tuning are practical for frequency agile antennas (FAAs)? a) Electrostatic and magnetostatic b) Piezoelectric c) Hydraulic and pneumatic d) All the above 9. What is a major advantage of liquid crystals over ferroelectric substrates? a) Lower bias voltage b) Higher switching frequency c) Higher bandwidth d) Larger physical size 10. What is the most widely used component type for continuous tuning FFAs? a) Schottky diodes b) Photodiodes c) MEMS d) Varactor diodes Need some help? Click here for the answers and explanations. |
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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while typing up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived... All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged. My Hobby Website: AirplanesAndRockets.com
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