A low-noise
block converter (LNB, for low-noise
block, or sometimes LNC, for low-noise
converter) is used in communications satellite
(usually broadcast
satellite
) reception. The LNB is usually fixed on or in the satellite
dish, for the reasons outlined below.
Universal LNB
A universal LNB
can receive both polarizations and the full range of frequencies in the satellite
Ku or C band
. Some models can receive both polarizations simultaneously through two different connectors, and others are switch able or fully adjustable in their polarization
.
Here is an example of Universal LNB
specifications:
- LO: 9.75 / 10.6 GHz.
- Freq: 10.7–12.75 GHz.
- NF: 0.7 dB.
- Polarization
: Linear
Standard North America Ku-band LNB
By covering a smaller frequency
range a LNB with a better noise
figure can be produced. Pay TV operators can also supply a single fixed polarization
LNBF to save a small amount of expense.
Here is an example of a Standard Linear LNB:
- Local oscillator: 10.75 GHz
- Frequency
: 11.7-12.2 GHz
- Noise
Figure: 0.5 dB
- Polarization
: Linear
North America DBS
LNB
Here is an example of an LNB used for DBS
:
- Local oscillator: 11.25 GHz
- Frequency
: 12.2-12.7 GHz
- Noise
figure: 0.7 dB
- Polarization
: Circular
C-band LNB
Here is an example of a North American C-band LNB:
- Local oscillator: 5.15 GHz
- Frequency
: 3.6-4.2 GHz
- Noise
figure: ranges from 15 to 100 kelvins (uses Kelvin ratings as opposed to dB rating).
- Polarization
: Linear
Dual/Quad LNB's
Two or Four LNB's in one unit to enable use of multiple receivers on one Dish.
Monobloc LNB's
a unit consisting of two LNB's designed to receive satellites spaced close together. For example in parts of Europe Monoblocs designed to receive the Hotbird (13E) and Astra 1 (19E) satellites are popular because they enable reception of both satellites on a single dish without requiring an expensive and noisy rotator.
