What is LNB?
The acronym LNB stands for Low Noise Block. This device is installed in front of a satellite dish, which receives a very low signal and amplifies it, changes the signal to lower frequencies and transmits them via cable to the receiver.
The expression Low Noise refers to the quality of the first transistor preamp. Quality varies in units designated as “noise temperature” or “noise figure”. The lower the noise temperature, the better. So, LNB with a noise temperature of 100 K is twice as good as – 200K. C-band LNBs typically have the lowest noise temperature, and Ka-band LNBs have the highest.
The expression Block refers to the transformation of a block of microwave frequencies received from a satellite into lower ones. Satellite broadcasting mainly occurs in the range from 4 to 12 or 21 Hz.
The diagram shows an input wave tube that is connected to a collecting feed or horn. As shown here, there is a vertical pin on the wide side of the wave tube, which extracts signals with vertical polarization as an electric current. Satellite signals first pass through a band-pass filter that passes only ultra-high frequencies. The signals are then amplified using LNA and then transmitted to the mixer.
In the mixer, everything that passes through the filter and amplifier captures the local oscillator and produces a wide range of distorted outgoing signals. This process includes generating the necessary types of signals. As a result, the mixer produces the necessary input signal and the local frequencies of the generator. The second type of signal passes through a filter and is sent through an L-band amplifier and through a cable.
Typically, the outgoing frequency is the input frequency minus the local oscillator frequency. In some cases, the opposite is true. In this case, the output spectrum is inverted.
These are all examples of simple LNBs with one LNA and one LO frequency.
There are more complex LNBs, especially for satellite television, where people want to receive signals of different frequencies or alternative polarization.
They will usually have two opposite LO frequencies, for example, 9.75 GHz and 10.6 GHz, with the possibility of receiving higher frequencies using the 22 kHz tone supplied through the cable. Such LNBs can be used to obtain 10.7 – 11.7 GHz using the lowest LO frequency of 9.75 GHz or 11.7 – 12.75 GHz using the highest LO frequency of 10.6 GHz.
Dual polarized LNB
This type has one cable going to the wave tube – it picks up the vertical polarization. If the incoming wave tube is circular, then it is possible to support two polarizations, and you can place it so that the two input probes are at right angles, then this will allow you to choose two opposite polarizations. Dual polarized LNB can be remotely turned on using different DC voltage. For example, 13 volts is vertical polarization, and 19 volts is horizontal.
If both input probes have their own amplifier, then you actually have two converters in one module that will have two output cables, one for each type of polarization. There are many variations of this design. For example, Quad LNB has 4 outputs for two bands. A similar design is convenient for apartment buildings.
Satellite TV antennas in the Marinek online store
Marinek company offers modern satellite fixed, ship and mobile TV antennas with high-performance LNB, with which you can solve the serious problems of organizing satellite TV broadcasting on a particular mobile or stationary object. Satellite antennas of famous brands are the basis for creating comfort when driving and parking, have the highest quality and are able to create additional value as part of the provision of services and create additional comfort.
Marinek experts offer satellite TV antennas of the most reputed brands:
Intellian, KVH, KNS, Cobham, Raymarine, Glomex, NavCom, Samyung, Viscom.
The product lines of the presented manufacturing companies include satellite TV antennas of various diameters, oriented to various market segments. The company’s specialists will help you choose and buy a satellite TV antenna based on your personal preferences and terms of reference. The following are the most popular models of the most famous brands, the implementation of projects based on which is especially popular among professional clients:
KVH TracVision HD11 (World Wide LNB)
Sea Tel 100 TVHD (Ka / Ku LNB)
RaySat SR 1500 (Linear / Circular LNB)
Intellian i2, i3, i4 (Aut. Ku LNB)
Intellian i6w, i9w (LNB WorldView)
Sea Tel 100 TV (Ku LNB)
KNS SuperTrack S12 (Linear / Circular LNB)
Raymarine 33 STV, 37 STV (LNB 2x)
Raymarine 45 STV, 60 STV (LNB 4x)