Give a reason to show that microwaves are better carrier of signals for long range transmission than radio waves.
Answers
Microwave transmissions
Wireless technology uses microwaves and radio waves to transmit information. Advantages are:
we can receive phone calls and email 24 hours a day
no wiring is needed to connect laptops to the Internet, or for mobile phones or radio
communication with wireless technology is portable and convenient.
Microwaves can be used to transmit signals over large distances if there are no obstacles between to reflect or absorb the beam. Another way to say this is that the transmitter and receiver are in line of sight (one can be seen from the other). This is why the transmitters are positioned high up, often on tall microwave masts. They cannot be spaced so far apart that, for example, hills or the curvature of the Earth stop the beam.
Microwaves are used to send signals to and from satellites. The satellites can relay signals around the Earth. Microwaves are used because they pass through the atmosphere and through the ionosphere. The signals may be for television programmes, telephone conversations, or monitoring the Earth (for example, weather forecasting).
When microwaves are transmitted from a dish the wavelength must be small compared to the dish diameter to reduce diffraction – the spreading out of the beam. The dish is made of metal because metal reflects microwaves well.