Editing Low-noise block downconverter (section)

==== Universal LNB ("Astra" LNB) ====
[[Image:astra lnb.jpg|thumb|left|120px|[[Astra (satellite)|Astra]]-type LNBF]]

In Europe, as [[SES (company)|SES]] launched more [[Astra (satellite)|Astra]] satellites to the [[Astra 19.2°E|19.2°E]] orbital position in the 1990s, the range of [[downlink]] frequencies used in the [[Fixed satellite services|FSS]] band (10.70–11.70&nbsp;GHz) grew beyond that catered for by the standard LNBs and receivers of the time. Reception of signals from [[Astra 1D]] required an extension of receivers' IF tuning range from 950–1,950&nbsp;MHz to 950–2,150&nbsp;MHz and a change of LNBs' local oscillator frequency from the usual 10&nbsp;GHz to 9.75&nbsp;GHz (so-called ''enhanced'' LNBs).

The launch of [[Astra 1E]] and subsequent satellites saw the first use by Astra of the [[BSS band]] of frequencies (11.70–12.75&nbsp;GHz) for new digital services and required the introduction of an LNB that would receive the whole frequency range 10.70–12.75&nbsp;GHz, the ''universal'' LNB.

A universal LNB has a switchable local oscillator frequency of 9.75/10.60&nbsp;GHz to provide two modes of operation: low band reception (10.70–11.70&nbsp;GHz) and high band reception (11.70–12.75&nbsp;GHz). The local oscillator frequency is switched in response to a 22&nbsp;kHz signal superimposed on the supply voltage from the connected receiver. Along with the supply voltage level used to switch between polarizations, this enables a universal LNB to receive both polarizations (vertical and horizontal) and the full range of frequencies in the satellite {{Ku band}} under the control of the receiver, in four sub-bands:<ref>{{cite web|url=https://pro.ses-astra.com/resources/dealers/dish_inst_broch1.pdf|title=Professional Dish Installation|publisher=ASTRA (GB) Limited|date=March 2005|page=7|url-status=dead|archive-url=https://web.archive.org/web/20110716043156/https://pro.ses-astra.com/resources/dealers/dish_inst_broch1.pdf|archive-date=2011-07-16}}</ref>

Here is an example of a universal LNB used in Europe:
* Noise figure: 0.2&nbsp;dB typical
* Polarization: Linear

{| class="wikitable"
|-
! colspan=2 | Supply
! colspan=2 | Block
! rowspan=2 | Local oscillator <br/>frequency
! rowspan=2 | Intermediate <br/>freq. range
|-
! Voltage
! Tone
! Polarization
! Frequency band
|-
| 13&nbsp;V 
| 0&nbsp;kHz 
| Vertical
| 10.70–11.70&nbsp;GHz, low
| 9.75&nbsp;GHz
| 950–1,950&nbsp;MHz
|-
| 18&nbsp;V 
| 0&nbsp;kHz 
| Horizontal
| 10.70–11.70&nbsp;GHz, low
| 9.75&nbsp;GHz
| 950–1,950&nbsp;MHz
|-
| 13&nbsp;V 
| 22&nbsp;kHz 
| Vertical
| 11.70–12.75&nbsp;GHz, high
| 10.60&nbsp;GHz
| 1,100–2,150&nbsp;MHz
|-
| 18&nbsp;V 
| 22&nbsp;kHz 
| Horizontal
| 11.70–12.75&nbsp;GHz, high
| 10.60&nbsp;GHz
| 1,100–2,150&nbsp;MHz
|}