As the orbit increases in radius, the angular velocity reduces, until it is coincident with the Earth's at a radius of 36000Km . Geostationary satellites providing global coverage For intercontinental communication, satellite radio links become a commercially attractive proposition. Space communication showed phenomenal growth in the 1970s, and will continue to grow for some years to come. The growth has been so rapid that there is now danger of overcrowding the geostationary orbit. The heavy usage of intercontinental traffic makes the satellite commercially attractive.
Satellites can cover large areas of the Earth.
This is particularly useful for sparsely populated areas. Over-crowding of available bandwidths due to low antenna gains. The high investment cost and insurance cost associated with significant probability of failure. High atmospheric losses above 30GHz limit carrier frequencies. A microwave antenna has two functions.