QUESTION 17 What is correct regarding an ideal isotropic antenna? a. An ideal is
ID: 3905602 • Letter: Q
Question
QUESTION 17 What is correct regarding an ideal isotropic antenna? a. An ideal isotropic antenna is a highly efficient antenna used extensively in today's communication systems b. An ideal isotropic antenna is a specialized antenna used to direct EM signal energy towards a specific direction c An ideal isotropic antenna is a theoretical antenna that does not exist in practice, but is useful in explaining power density and unguided EM signal attenuation d. None of the above are correct statements QUESTION 18 Select the correct statement(s) regarding optical signals a. Optical signals are immune from radio frequency interference (RFI) b. Optical signal operate in the THz frequency range, which can support high data throughput. o c. Optical signals cannot be collected using RF antennas. d. All are correct statementsExplanation / Answer
17. An ideal isotropic antenna is an ideal antenna that doesnot exist practically and radiates its power uniformly in all directions. It used as a reference antenna for the antenna gain.
The antenna gain is often specified in dBi, or decibels over isotropic. This is the power in the strongest direction divided by the power that would be transmitted by an isotropic antenna emitting the same total power.
Thus the correct option is
c.An ideal isotropic antenna is a theoritical antenna that does not exist in practice, but is useful in explaining power density and unguided EM signal attenuation.
18. Optical signals use light waves(electromagnetic frequency) for transmission on signals whereas radio frequency is used in wireless communication through radio waves. They have different frequency range and hence optical signals are immune to RFI and also optical signals cannot be detected by RF antennas. Thus the correct answer is:
b. Optical signals operate in the THz frequency range which can support high data throughput