Up converter (satellite transmission)
An upconverter (English upconverter or also block upconverter or BUC ) is in communications technology that part of the transmission chain (transmission device) that transmits the signal emitted by the modulator , which in satellite technology is usually at 70 or 140 MHz (or also in the L- Tape ) is converted to the final transmission frequency.
This can e.g. B. the Ku band (12-18 GHz). The signal chain then looks like this:
Video signal (SDI) → encoder (ASI) → multiplexer (DVB-ASI) → modulator (70 MHz) → up converter (e.g. 14.3 GHz) → high power amplifier (HPA) → antenna
Up -converters are to be regarded as the counterpart to the low-noise signal converter (LNB from English Low Noise Block Converter ). Like the latter, they have a corresponding oscillator (LO from English Local Oscillator ), onto which the frequency signal is then mixed.
In addition to being used in signal feed (satellite signal feed or SNG), an up-converter is used to implement an uplink of images and data or bi-directional internet access via satellite . In Europe this may be used. a. SES Broadband for the Astra2Connect service (the up-converter and LNB are combined in one housing as a so-called interactive LNB with the marketing name: iLNB and use the Ku-band) and Eutelsat for the tooway Internet access service , which uses KA-SAT in the eponymous Ka-band is carried out. (With the latter, a Ka-band LNB and a Ka-band up-converter are mechanically coupled to a common feed horn by means of a flange).
Professional boost converters generate the oscillator clock as a multiple of a reference clock that is supplied externally. The signal-to-noise ratio is specified as a function of the frequency accuracy (in: Hz steps). Corresponding end-user solutions (e.g. in satellite modems) do not allow any settings here (due to approval and to protect against incorrect configuration), so, like most LNBs, are fixed in production.
