1. The audio power of the human voice is concentrated at about 300Hz. Antennas of the appropriate size for this frequency are impracticable large, so that to send voice by radio the voice signal must be used to modulate a higher (carrier) frequency for which the natural antenna size is smaller.
a. What is the length of an antenna one-half wavelength long for sending radio at 300Hz?
b. An alternative is to use a modulation scheme, as described in Chapter 5, for transmitting the voice signal by modulating a carrier frequency, so that the bandwidth of the signal is a narrow band centered on the carrier frequency. Suppose we would like a half-wave antenna to have a length of 1 meter. What carrier frequency would we use?
2. You are communicating between two satellites. The transmission obeys the free space law. The signal is too weak. Your vendor offers you two options. The vendor can use a higher frequency that is twice the current frequency or can double the effective area of both of the antennas. Which will offer you more received power or will both offer the same imporevement, all other factors remaining equal? How much imprevement in the received power do you obtain from the best option?
PS.
Ah~ There're 6 more assignments beside them.
Moreover floor plan for Design Class and 3 reports for cultural studies.
The midterm examination is drawing near.
we MUST stay up all night every day. No time for being in the bed.
My brain grew dim with use.
a. What is the length of an antenna one-half wavelength long for sending radio at 300Hz?
b. An alternative is to use a modulation scheme, as described in Chapter 5, for transmitting the voice signal by modulating a carrier frequency, so that the bandwidth of the signal is a narrow band centered on the carrier frequency. Suppose we would like a half-wave antenna to have a length of 1 meter. What carrier frequency would we use?
2. You are communicating between two satellites. The transmission obeys the free space law. The signal is too weak. Your vendor offers you two options. The vendor can use a higher frequency that is twice the current frequency or can double the effective area of both of the antennas. Which will offer you more received power or will both offer the same imporevement, all other factors remaining equal? How much imprevement in the received power do you obtain from the best option?
PS.
Ah~ There're 6 more assignments beside them.
Moreover floor plan for Design Class and 3 reports for cultural studies.
The midterm examination is drawing near.
we MUST stay up all night every day. No time for being in the bed.
My brain grew dim with use.
