ADInstruments S7200 Operation Manual page 105

AD INSTRUMENTS
About LNB local oscillator
C band LNB single local oscillator use 5150MHz and 5750MHz. IRD receives signal
frequency range is 950~2150MHz, and C band full bandwidth about 500MHz, only
about half of the 950~2150MHz. Some new products provide two sets of circuits
to respectively handle horizontal polarization and vertical polarization signals.
Two local oscillator frequency respectively set up to 5150MHz and 5750MHz.
After signal mixing, the horizontal polarization and vertical polarization
respectively output 950~1450MHz (5150 – 4200 = 950, 5150 – 3700 = 1450) and
1550~2050MHz (5750 – 4200 = 1550, 5750 – 3700 = 2050), two signals in the IRD
receive frequency range.
The Ku band satellite signal downlink frequency range from 10.7GHz to 12.75GHz,
the bandwidth about 2.05GHz, about 4 times C band bandwidth. Use one local
oscillator frequency to receive full bandwith signal is difficult on Ku band. So
divided the 2.05GHz bandwidth into several frequency bands, and every
frequency band use different local oscillator frequency. Often used local oscillator
frequency are 9.75GHz, 10.6GHz, 10.75GHz, 11.25GHz, 11.3GHz, etc. The follow
table give the every type local oscillator frequency and corresponding receive
frequency and IF range.
Different LO Ku band LNB receive signal and output IF frequency range
LO(GHz) Receive Signal frequency range (GHz)
9.75
10
10.6
10.75
11.25
11.3
S7200 TV Signal Analyzer Operation Manual
10.7~11.9
10.95~12.15
11.55~12.75
11.7~12.75
12.2~12.75
12.25~12.75
LNB output IF Range (GHz)
950~2150
950~2150
950~2150
950~2000
950~1500
950~1450
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