IF AMPLIFIERS
The output of the mixer is an IF signal, at a fairly low level. Since this signal is of a specific
bandwidth only, it can be easily amplified, significantly. An LNB often includes atleast 2 stages of
IF amplification. This amplified signal is then filtered and fed to the output via a DC blocking
capacitor. The capacitor allows the signal to pass through but steers the power coming from the
satellite receiver, to the LNB power supply.
UNIVERSAL LNB
KU Band LNBs today effectively split the KU band into 2 frequency segments and utilise separate
local oscillators for each of these frequency segments. As an example, the COLORADO Universal
LNB receives satellite transmissions from 10.7 GHz to 12.75 GHz. For the lower frequency band,
the local oscillator operates at 9.75 GHz. For the upper frequency band, the local oscillator
operates at 10.6 GHz, or sometimes 10.75 GHz.
The necessary Local Oscillator is activated by send the LNB a burst of 22 KHz signals, from the
satellite receiver. When the Satellite receiver is told by the user to tune into a Satellite Channel
between 11.7 GHz to 12.75 GHz, the 10.6 GHz local oscillator is activated with a burst of 22 KHz
signals.
The absence of the tone burst, activates the 9.75 GHz local oscillator.