A satellite in geostationary orbit is used to transmit data via electromagnetic radiation. The satellite is at a height of 3.1A????1104km , above the surface of the earth, and we assume it has an isotropic power output of 36.1kW , (although, in practice, satellite antennas transmit signals that are less powerful but more directional).

Imagine that the satellite described in the problem introduction is used to transmit television signals. You have a satellite TV reciever consisting of a circular dish of radius R which focuses the electromagnetic energy incident from the satellite onto a receiver which has a radius of 3.69 x 10^-2 m.

For simplicity, assume that your house is located directly beneath the satellite (i.e. the situation you calculated in the first part), that the dish reflects all of the incident signal onto the receiver, and that there are no losses associated with the reception process. The dish has a curvature, but the radius Rrefers to the projection of the dish into the plane perpendicular to the direction of the incoming signal.

QUESTION

How large does the radius R of the dish have to be to achieve an electric field vector amplitude of 5.7 x10^-4V/m , at the receiver?