Customized Communications Since 1986


AC Alternate current. AC is used for PSU and most com- mon is 110 or 220-230 Volt.

AGC Automatic Gain Control. Adjust an output level to be same independent of the input level in an amplifier.

Aperture Refers to the diameter of a satellite antenna. As an example a 3-meters antenna has an aperture of 3 meters.

BDC Block Down Converter. Same as LNB without the low noise option, usually this also means that the input has a coaxial connector instead of a waveguide input.

Beacon Satellite signal that are used for large diameter antennas active position tracking.

BUC Block Up Converter. Used for converting L-band to satellite uplink frequencies.

C-band Input frequency range 3.400 – 4.800 GHz. Variat- ed parts of this band used in different product variants. For monitoring of C-band uplink also 5.700 – 7.250 GHz.

dBW Decibel Watt is a unit for the measurement of the strength of a signal expressed in decibels relative to one Watt. Typically used for to express the level of EIRP of a satellite beam or footprint.

DC Direct current. DC is used for power feed to our prod- ucts, 12-24 Volt DC (depending on product range).

DRO Dielectric Resonator Oscillator. Controls the fre- quency of the Local oscillator (LO) in a LNB.

DVB-S2X DVB-S2X is an extension of DVB-S2 satellite digital broadcasting standard. Compared to DVB-S2, efficiency gains up to 51% can be achieved with DVB-S2X. Amongst improvements are:
– Higher Modulation Schemes (64/128/256APSK).
– Smaller Roll-off factors.
– Improved filtering making it possible to have smaller carrier spacing.

EIRP Equivalent Isotropically Radiated Power is the amount of power that a theoretical isotropic antenna (which evenly distributes power in all directions) would emit to produce the peak power density observed in the direction of maximum antenna gain. EIRP can take into account the losses in transmission line and connectors and includes the gain of the antenna. The EIRP is often stated in terms of decibels over a reference power emitted by an isotropic radiator with an equivalent signal strength (dbW).

Footprint The surface on earth covered by a satellite transponder. The centre area of a footprint is called “spot” and in that area also the signal strength has the highest value (dBW).

Frequency Stability Used for the stability of a LO (Local oscillator) and is specified as ppm or +/- kHz or +/- MHz (DRO). General recommendation is to use ± 10% of the Symbol rate.

Gain flatness The maximum gain variation over fre- quency within a frequency band. Note. Also other gain variations exists on a LNB, eg over temperature and part to part spread.

GEO GEO is short term for Geostationary Earth Orbit. Refers to satellite’s orbit at 35,786km above the equator at same speed and direction as the earth rotation on its axis. That make them as “fixed” in the sky.

G/T A figure of merit of an Antenna a Low noise amplifier (LNA) combination expressed in dB. The higher the G/T the better the system.

HTS High Throughput Satellite is a classification for com- munications satellites that provide at least twice, though usually by a factor of 20 or more,[1] the total throughput of a classic FSS satellite for the same amount of allocated orbital spectrum thus significantly reducing cost-per-bit.

IP3 Third Order intercept point. Also named “TOI”. A “high” IP3 value make it possible to receive signals at a “high” level without distortion at the output.

IR Image rejection in dB from input to output for a LNB or BDC. There is always a small portion of unwanted con- version of 2x the output frequency +/- LO frequency de- pending if it’s lower or upper side (see LO section). This value specifies the attenuation of the unwanted signal of the frequency conversion.

Ka-band Input frequency range 17.300 – 22.200 GHz.

Ku-band Input frequency range 10.700 – 12.750 GHz. Low band 10.700 – 11.700 GHz, High band 11.700 – 12.750 GHz.

LEO Low Earth Orbit satellites orbit 160 to 2000km above earth and take approximately 1,5 hours for a full orbit and only cover a portion of the earth surface.

LNA Low Noise Amplifier. Used as a preamplifier be- tween antenna and the earth station receiver. For best performance it shall be located as near the antenna as possible. Always used together with a BDC (Block Down Converter). NOTE. A high performance LNB can replace the LNA-BDC combination for the same or even better performance.

LNB Low Noise Block downconverter. A combination of a LNA (Low noise amplifier) and converter built into one device. “Block” means a limited frequency range is con- verted eg 10.7 GHz – 11.7 GHz. Also named LNC.

LO Local oscillator, controls the input to output frequen- cy conversion ratio in an LNB or a BDC. The LO can be on upper side or lower side of the RF input frequency. If the LO is on the upper side in relation to the input frequency, the output frequency is spectrally inverted.
Formulas: Lower side LO, Input frequency – LO frequency
= Output frequency
Upper side LO, LO frequency – Input frequency = Output frequency

MEO The most common use for satellites in this region is for navigation, communication, and geodetic/space envi- ronment science. The most common altitude is approxi- mately 20,2 km, which yields an orbital period of 12 hours, as used, for example, by the Global Positioning System (GPS). Other satellites in medium Earth orbit include Glonass (with an altitude of 19,1 km and Galileo (with an altitude of 23,222 km) constellations. Communications satellites that cover the North and South Pole are also put in MEO.

Optical wavelength The wavelength (frequency) of the light used in our fiber products, we use ITU standard- ized wavelengths. ITU International Telecommunications Union. Worldwide standardizing organ for telecommuni- cations.

P1dB Also named “oP1dB”. This means the output 1dB compression point of an amplifier.

Phase Noise Value of phase noise is a factor that is very important regarding reception of DVB-S2X and also low symbol rate transponders.

PLL Phase Lock Loop. Are used for improved frequency stability of a Local Oscillator.

ppb Parts Per Billion.

ppm Parts Per Million.

Quadlink A Quadlink system include a Fiber Transmitter and a Fiber Receiver. It transmits and receives all signals using only one fiber cable.

Quattro LNB Output frequencies are divided in to 4 RF outputs. Low band Vertical polarisation, Low band Hori- zontal polarisation, High band Vertical polarisation, High band Horizontal polarisation.

Reference High stability/low noise oscillator. Used for control of PLL LO in a LNB or BDC. It can be oscillator internal or supplied externally depending on the appli- cation. Common frequency is 10MHz. When used with a high stability externally reference, extreme high LNB LO stability can be achieved, down to ±30 ppb (parts per billion).

SMW Swedish Microwave AB. A professional manufactur- er of microwave solutions.

SNG Satellite News Gathering. Electronic news-gathering can involve anything from a lone reporter taking a single professional video camera out to shoot a story, to an en- tire television crew taking a production or satellite truck on-location to conduct a live news report for an outside newscast. The vehicle on which the electronic equipment is fitted is called DSNG (Digital Satellite News Gathering).

SOTM Satcom On The Move, or Satellite communications On The Move, is a phrase used in the context of mo-
bile satellite technology, specifically relation to military ground vehicles. The basic principle behind Satcom On The Move is that a vehicle equipped with a satellite an- tenna is able to establish communication with a satellite and maintain that communication while the vehicle is moving. The orbital periods of MEO satellites range is from about 2 to nearly 24 hours

Sun outage A Sun outage, Sun transit or Sun fade is an interruption in or distortion of geostationary satellite sig- nals caused by interference (noise) from solar radiation. The effect is due to the Sun’s radiation overwhelming the satellite signal.

Symbol rate The Symbol rate variates for different satellite transmissions and are most often within a range of 1 to 45 M/Symbols.

TLT Test Loop Translator. A test loop translator is a type of radio frequency converter or heterodyne, used to translate between uplink and downlink segments (gen- erally in the same band), to allow for ”loop-back” testing and calibration of a satellite ground station without the need to interface with the satellite. The test loop trans- lator is an extremely valuable tool for evaluating the performance of satellite earth stations. It allows the user to carry out analysis, alignment and testing without incur- ring satellite airtime costs and the risk of interfering with other satellite users.

Uplink band Transmit frequencies to satellite. Products for different uplink frequency bands are available. Ask for more information.

VSAT Very small aperture terminal (VSAT) is a two-way satellite ground station with a dish antenna that is smaller than 3 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Data rates range from 4 kbit/s up to 16 Mbit/s. VSATs. are used to transmit narrowband data VSATs. are also used for transportable, on-the-move (uti- lising phased array antennas) or mobile maritime commu- nications.

VSWR Voltage Standing Wave Ratio. Used for measure- ment of RF impedance matching.

WDFL Wideband Dual Fiber output LNB.

WDL Wideband Dual output LNB.

X-band Input frequency range normally 7.25-7.75 GHz, Uplinks and earth observation downlinks shares band 7.75
– 8.5 GHz.

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SMW is a leading manufacturer of professional LNBs for the satellite market. We have helped customer in more than 127 countries.
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