After you read and made yourself familiar with the following topics, please answer /discuss the following 15 questions. Your answers should have detailed explanations. Topics: Antenna characteristics, Reflectors, Satellite orbits, Application of geostationary satellites, Isotropic radiation, Half-wave dipole, radiation resistance, radiation pattern, far field region, gain and diversity, directivity, folded dipole, monopole dipole, ground plane antenna, loop antennas, discone antenna.
1) What 2 signals does a GPS (Global positioning system) transmit?2) What does GEO stand for?
3) All else being equal, larger receiving antennas receive a stronger signal than smaller antennas. Why is that?4) Why is the antenna height important for line-of-sight propagation?5) Why is the antenna height important in mobile communication, even when the distances involved are much less than the distance to the horizon?6) What is an LEO satellite and how far from Earth?7) Explain geostationary satellite propagation time.8) Is it faster to send a signal by fiber optics across the town compared with sending a RF wave through a satellite with the speed of light?9) There is a geostationary satellite about 35,000 Km above the Earth’s surface between city-A and city-B. How long does it take for a signal from city-A gets to city-B? The speed of light is 300,000 Km / sec.10) There is a geostationary satellite about 45,000 Km above the Earth’s surface between city-A and city-B. A person in city-A will ask a question from another person in city-B. How long does it take for the person in city-A to hear an answer from city-B. The speed of light is 300,000 Km / sec.11) What is the relationship between the number of communication satellites at lower and higher altitudes?12) With a half-wave dipole antenna (? / 2), we want to receive an 80-MHz signal. Find the length of the dipole when ( ? = c / f ).13) The Earth is considered as an antenna a good conductor. Can you explain the effect of ground reflection if a transmitter is connected between the ground and the antenna?14) The Earth is considered as an antenna a good conductor. If a transmitter is connected between the ground and the antenna with physical length of ? / 4, what is the electrical length of the antenna?15) Explain what an electrical antenna does.