2006-08-17 19:06:32 · 3 answers · asked by mann 1 in Education & Reference ➔ Higher Education (University +)
Caught you, the uplink freq is always greater than the down link frequency!
Basically, its to do with the dish size- the uplink is a narrow beam, focussed only on the satellite itself! the higher the frequency, the higher the gain for the same dish size!
The same or another dish is also required to downlink from the satellite to ground, mostly in a dispersed manner. A smaller dish will disperse the beam as required at the satellite end!
On the ground side, at the transmit end, massive dish antennas are used just to pump sufficient effective power towards the satellite, while equally massive dish antennas are required for catching communications signals, while the average downlink broadcast for the TV sector is small enough, since the satellite pumps power in the TV bands, to make reception easy!
Higher uplink bandwidths will need higher frequencies, if the downlinks contain separate information. ON board a satellite, power is one of the most critical things, and the communications frequency has a lot to do with that!
2006-08-17 19:37:02 · answer #1 · answered by logikal 2 · 0⤊ 0⤋
On the ground your pumping, well thats the wrong word, but simular effect because your going up thru an atmosphere from a greater atmosphere. Your sine waves are shorter to start.
2006-08-17 19:19:58 · answer #2 · answered by Marcus R. 6 · 0⤊ 0⤋
Large towers, small houses.
Cancer
2006-08-17 19:10:57 · answer #3 · answered by halsru 2 · 0⤊ 0⤋