LNB stands for low-noise block down converter, is the receiving device mounted on satellite dishes used for satellite TV reception, which collects the radio waves from the dish. Also called a low-noise block, LNC (for low-noise converter), or even LND (for low-noise down converter), the device is sometimes wrongly called an LNA (low-noise amplifier).
The LNB is a combination of low-noise amplifier, frequency mixer, local oscillator and IF amplifier. It receives the microwave signal from the satellite collected by the dish, amplifies it, and downconverts the block of frequencies to a lower block of intermediate frequencies (IF). This downconversion allows the signal to be carried to the indoor satellite TV receiver using relatively cheap coaxial cable; if the signal remained at its original microwave frequency it would require an expensive and impractical waveguide line.
Input Frequency | 3.4 to 4.2Ghz |
L.O. Frequency | 5150MHz(±500 MHz@25℃) |
Output Frequency | 950-1750MHz |
L.O. Leakage Input Port | 45dBm |
L.O. Stability | ±1.5MHz(-40℃to+70℃) |
Noise Figure | <17°K typ |
Conversion Gain | >65dB typ |
Gain Flatness | ±1 dBm(max) |
Intput VSWR | 2.5:1(max) |
Output VSWR | 2.0:1(max) |
Output Connector | F-female Connector |
Output Impedance | 75Ω |
Cross Polar Isolation | 20dB(min) |
Image Rejection | 45 dB (min) |
Phase Noise | -75dBc/Hz@10kHz(max) |
Supply Voltage | 1)11.5-14.0v(Vertical Polarization) , 2)16.0-19.0v(Horizontal Polarization) |
Operating Temperature | -40℃to+70℃ |
Storage Temperature | -40℃to+80℃ |
Relative Humidity | 0%-95% |
