Question

1.

We are looking to make a radio transmitter using a Phone (with a speaker connected), a 9V battery, a function generator delivering a voltage v (t), a metal rod and an integrated circuit called voltage multiplier.

a) What are the functions of the different components of this transmitter?

b) Propose a schema for this issuer. It will be assumed that the Phone is similar to a function generator delivering a voltage u(t) corresponding to the voltage collected at the speakers of the phone. (6 points)

c) Given that v(t) is a signal with a 200 kHz frequency if we want to pick up the signal broadcast by our transmitter using a radio, on which position, FM, SW, MW or LW, should be put the switch of this radio?

Answer 1

a) The functions of the radio transmitter used here is to detect the function generator harmonics, the voltage multiplier circuit is used to step up the 9v used.The metal rod is for accurate setup like in radio or may work as antenna in the transmitter circuit.c) If we want to pick up the signal broadcast by our transmitter using radio,the switch of the radio should be in FM position.