which technique uses two different antennas to reduce traffic on the same frequency?

Antenna sizes are proportional to wavelength of EM wave. So higher frequency implies shorter wavelength . So size of antenna on satellite would be compact. Also the frequency used should have energy such that it’s not absorbed in any layers of atmosphere (energy should be lower than bandgap of material).

Satellites communicate by using radio waves to send signals to the antennas on the Earth. The antennas then capture those signals and process the information coming from those signals.

Satellite communication is an example of the broadcast mode of communication.

Digital modulation techniques are used in the satellite communication system, because.

Mobile phones communicate to a mobile cell tower using radio waves, towers communicate with satellites using microwaves. Microwaves are used as they can pass through the atmosphere . This signal can be sent to a satellite and used to communicate around the world (more than one satellite is required for this).