For communication satellites the range is much higher than that of communication relay. Communication Satellite can cover up to several thousands of kilometers.
For communication relay, the uplink and the downlink frequency is the same. But for communication satellites the uplink and the downlink frequencies are different in order to avoid interference.
Different frequency bands used in satellite communication are
Ultra high frequency band (UHF).
420-450 MHz
Also known as 70 centimeters (cm). This is the lowest frequency amateur UHF band. Groundwave coverage is quite limited compared to 2 meters due to high absorption. Satellite, EME and terrestrial DXing are popular on this band. Fast scan TV has also found a home on 430 MHz. Lots of FM activity between 440-450 MHz. Lots of machines are linked to 2 meters! The longest Element of a beam for this band is about 12 to 13 inches on the low end!
902-928 MHz
Not much activity on this band so far due to a lack of suitable equipment.
Also this is a shared band with other services.
1200-1300 MHz
1.2 GHz is a HUGE band with lots of room for experimenters. EME and satellite are popular up here and in some parts of the US there are very active FM repeaters. Antennas are VERY small! Not a lot of terrestrial DXing but during contests there is some activity. Antennas for small signal work are quite impressive with lots of elements on short booms. Dishes are practical on this band.
C-Band:
All C-Band downlink frequencies will fall between a minimum of 3.4 Ghz and a maximum of 4.8 Ghz
X-Band:
x- band ranges from 8 to 12 GHz.
Ku-Band:
All Ku-Band downlink frequencies will fall between a minimum of 10.7 Ghz and a maximum of 12.75 Ghz
Ka-Band:
Ka band ranges from 26.5 to 40 GHz
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