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The amplifier plays a key and often underrated role in satellitecommunications. The evolution of satellite-based communications –the high power satellites and more sophisticated capabilities - hasgiven rise to a new generation of amplifiers. They are smaller, offersuperior intermodulation characteristics, lower power consumption,lower operating costs and longer life. They are also ruggedised andable to withstand extremes of both weather and temperature

The newer Solid State Power Amplifiers (SSPA) technology hasbeen replacing the older Travelling Wave Tube Amplifier (TWTA)vacuum technology for some decades now but one of the few appli-cations that has resisted this change until fairly recently has beensatellite earth station applications. However, TWT amplifiers are stillpopular and the argument seems to be that some amplifiers can dothe job better than others. Therefore users must simply choose theright amplifier for the job.

Type of amplifierHigh Power Amplifiers (HPA) amplify the signal to be transmittedfrom a satellite earth station before it is sent to the satellite and thereare various types of amplifier used to achieve this depending on lin-earity, reliability and cost.

Klystron amplifiers have a high power output and are easy torepair and have a long life of up to eight years. They tend to be largerand heavier and are often used in the military, for example.

TWTAs were invented during the Second World War by RudolfKompfner in a British radar lab. The device uses foot-long vacuumtubes to amplify signals. They amplify signals from a wide range offrequencies and can handle an entire satellite from just one dish.TWTAs are small but can be difficult to repair, are more expensiveand have a shorter life-span of 4-6 years.

Overall, the TWTA basically has more to go wrong. They containa tube and filament and therefore the mean-time-between-failure(MTBF) is higher than that of an SSPA due to its construction.

SSPAs use solid state electronics rather than a tube. They use acombination of quartz-based oscillator clocks and signal mixers toincrease power. Should a component fail within the amplifier thenthe signal would weaken but the amplifier would not lose power com-pletely. Power consumption can be higher but developments in thetechnology have seen companies producing SSPAs that use a greatdeal less power than they originally did. SSPAs were initially believedto be too expensive, too large and heavy and also less reliable thanTWTAs.

The latest innovationsNext generation satellite amplifiers are enabling more sophisticated satellite communications.Amplifier manufacturers are constantly modifying their products to make them smaller, to use lesspower and to operate at lower OPEX. SEA finds out about some of the latest products on themarket.

New colour LCD touch screen user interface.

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They also suffered with heatsink issues that meant that they wereprone to overheating.

WavestreamWavestream has introduced new indoor and outdoor PowerStream400W C-band solid state power amplifiers that are plug and playreplacements for traditional unlinearized 750W TWTA products usedin satellite communications, teleport and satellite newsgathering sys-tems. The new PowerStream 454C-i and 454C-o products comple-ment Wavestream’s 600W C-band product family, and provide a lowerpower, cost effective solid state solution to support applications wherelarger antennas or more powerful satellites are used.

“Wavestream continues to expand its product portfolio to meetthe demand for high power solid state amplifiers that offer integra-tors a convenient, form/fit/function upgrade path to replace ageingTWTA technologies,” stated Cliff Cooke, President and Chief Execu-tive Officer of Wavestream. “Our new PowerStream 400W C-bandproducts provide the power and performance needed to supportbroadcast satellite operations, while creating dramatic cost savingsvia improved efficiency, reduced energy consumption and the elimi-nation of expensive system redesigns and downtime.”

The PowerStream product family incorporates Wavestream’sfield-proven, next generation Spatial Power Advantage technologyto provide high output power and greater efficiency. When used in aredundant configuration, PowerStream products draw less power than750W unlinearised TWT system solutions and require no warm uptime, helping improve reliability and reduce lifecycle maintenancecosts.

The PowerStream 454C-i is a 400W indoor unit suitable for mo-bile and fixed rack-mount satellite communications systems. ThePowerStream 454C-i includes an easy-to-view front panel displayscreen and quick-touch function keys for convenient access to a va-riety of system status data, including power, temperature, fault, andlocal/remote information.

The PowerStream 454C-o is an outdoor 400W C-band amplifierthat can be mounted close to the antenna to significantly reducewaveguide loss. The PowerStream 454C-o is ruggedized to with-stand harsh environments, and can be easily controlled from a re-dundancy controller or an operator’s computer, providing conven-ient, indoor desktop access to power, temperature and status infor-mation.

Optional 1:1 redundancy kits are available to insure uninterrupted,reliable transmissions and accommodate a variety of customermounting and power level requirements. For indoor data centres,customers can easily install Wavestream’s redundancy kit into anexisting cabinet or rack configuration without the need for additionalspace or system redesign.

AdvantechAdvantech Wireless has received significant orders for its new 900

Watt and the 1,600 Watt Ku-band Outdoor Solid State Modular Am-plifier System known as the ‘Summit’ series. The company believesthe Summit series to be the highest power and most reliable amplifi-ers made with solid state technology.

The Summit lines of SSPA are designed for satellite up-link ap-plications in ground station terminals. The system is expandible upto 16-modules. Full remote monitor and control capability of the sys-tem is achieved via serial or Ethernet interface.

The outdoor system is fully modular and can provide output powerof up to 3,500W in C-band, 2,800W in X-band and 1,600W in Ku-band. The design of the Summit line is based on Advantech Wire-less’ tradition of high power high linearity and high efficiency line ofproducts. The Summit systems present distinct advantages over highpower TWTA systems in terms of reliability, cost, maintainability andease of operation. The Summit range is completely modular and fea-tures hot swappable elements, remote monitor and control capabil-ity via RS485 or Ethernet ports, input and output, sample monitorports, gain adjustment (local or remote), fully weather resistant, tem-perature gain compensation, automatic over-temperature shutdownand automatic high reflected power shutdown.

“Our Summit series SSPA product line is clearly the market leaderin power, performance and reliability”, said David Gelerman,Advantech Wireless CEO. “We are the only company in the worldmanufacturing this high power, modular SSPA with built-in redun-dancy. We are the first to market with this amazing technology be-cause of our tradition of investing 20 percent of our revenues intoresearch and development. Advantech Wireless will always be thenumber one source for all satellite communications needs.”

MCLMCL´s MT3400 and MT4400 Outdoor TWT Amplifiers have alreadybeen described as reliable, rugged, and economical solutions forsatellite uplink applications but now they are also energy efficient.The MT3400 is available with a 400W linear TWT, drawing 1,100Watts as opposed to 1,500 Watts, while the MT4400 offers a 750Wlinear TWT, drawing 2,000 Watts versus 2,400 Watts. These new TWToptions are only offered in Ku-band at this time. Both of these state-of-the-art amplifiers are available for C-, X-, Ku-, and DBS-band ap-plications and include such features as rugged construction for ex-treme environments, software communications configuration for bothremote and computer interfaces, continuous attenuator adjustmentshown in dB, auto power control and status, and much more. TheMT3400 and MT4400 can also be customised to include optionssuch as an internal L-band block upconverter, an internal lineariser,Ethernet interface, option at 60°C, or a hand-held or remote control-

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ler. Redundancy can be achieved through 1:1, 1:2, or phase com-bined systems.

Comtech EF DataComtech’s HPOD series of High-Power Outdoor SSPAs provide acost-effective, more linear replacement for TWT amplifiers in satcomterminals. Featuring field replaceable power supplies and redundantsystem control, the high-power units were built with the user in mind.The units utilise low loss combining technique and MCP-based tem-perature versus gain compensation. The phase-combined systemsallow the outputs of two amplifiers to be summed together for evenhigher power. And, with the unique approach to L-band frequencyconversion, the optional “Smart BUC” functionality eliminates DC and10 MHz from the input coax. Providing more value than competitivesolutions, the base units include temperature compensation, sam-ple ports, power monitor, field-replaceable power factor correctedsupply and full remote monitor and control capabilities.

The SPOD series of High-Power Outdoor (SPOD) C-, X-, andSSPA provide a cost-effective, more reliable replacement for TWTamplifiers in satellite communications terminals. The SPOD deliversits rated power at the 1dB compression point, to the transmitwaveguide flange. A SPOD consists of an SSPA module with theMonitor/Control Processor (MCP), an integrated power supply, anda field replaceable fan assembly. The amplifier features a ComtechEF Data low loss combining technique and MCP-based temperature

The leader in high power SATCOM amplifier productsComtech Xicom Technology has grown to be the world’s leading SATCOM power amplifier supplier, offering the broadest product line inthe industry. For more than 20 years, its focus on customers, innovation and quality has created a tremendous breadth of products anda company renowned for excellence.

Xicom provides rugged, highly efficient and reliable amplifier products for commercial and military broadcast and broadband appli-cations around the world including:

• Travelling Wave Tube Amplifiers (TWTAs);• Klystron Power Amplifiers (KPAs);• Solid-State Power Amplifiers (SSPAs); and• Block Upconverters (BUCs).

This product range encompasses power levels from 8 W to 3 kW, with coverage across the 2 GHz to 45.5 GHz frequency spectrum.Highly regarded for its reliable output power and efficiency, Xicom High Power Amplifiers (HPAs) are used in critical communicationslinks on the ground, in the air and on the sea. They support fixed traditional and direct-to-home broadcast, mobile satellite newsgathering (SNG), transportable and flyaway systems, secure high data-rate communications and broadband access.

Xicom continues to introduce innovative SATCOM amplifier products.

New miniature 50W X-band BUCXicom’s Model XTS-50X1-B1 X-BUC, is the perfect solution for commercial and military users ready to take advantage of new X-bandcapacity on XTAR and Wideband Global SATCOM (WGS) satellites. High power in a compact package enables system integrators tooffer much higher data-rate uplinks with rugged, compact and transportable SATCOM terminals. The X-BUC provides 50 Watts of 1-dBcompressed output power in a self-cooled, feed-mountable package specifically designed to operate in harsh environments and meetthe stringent RF requirements of today’s X-band systems.

The new X-BUC is packed full of performance features including temperature compensation, gain control, harmonic filtering and anoutput isolator. All this comes in a compact outdoor unit weighing 10.5 pounds and measuring only 10.58 inches long x 5.68 inches widex 4.43 inches high. This high performance design provides more than 32 Watts of linear output power as defined for the WGS system,making it the most powerful 10.5-pound X-band unit anywhere.

New rack-mount product line features LCD touch screen control interfaceXicom’s new XTRT series of 19-inch rack-mount TWTs feature a LCD touch screen, which provides an easy-to-use graphical interfacefor monitoring and controlling the power amplifier.

The new touch screen front panel displays the HPA’s operational status including power output and temperature, graphical displaysof parameter trend analysis, and event logs. Local and remote diagnostics can also be easily performed via an Ethernet interface.

With this new display the need for separate external controllers for common architectures is eliminated because it visually presentsand controls waveguide switches and a combiner, providing both cost and space savings. An additional valuable feature is that alloperational data is saved within the amplifier’s non-volatile memory, providing a complete history of the HPA in the event the unit needsservice or repair. The new touch screen front panel controller is available as an option on all Comtech Xicom Technology rack-mountTWTAs.

versus gain compensation. The SPOD SSPAs are equipped withuseful features that other manufacturers offer as options. Included ineach unit’s base price are temperature compensation, sample ports,power monitor, power factor corrected supply and full remote moni-tor and control capabilities, including Ethernet HTTP pages andSNMP.

Steady demand in AsiaDemand for satellite connectivity in the Asian region is presentlyrooted in two applications - cellular backhaul and disaster recovery.These two market sectors will provide a great deal of business forthe industry long into the future and therefore will fuel demand foramplifier technology. They are both important and invaluable to thepeople of Asia due to its vulnerability to disasters such as earth-quakes and also the dispersed nature of the population. The Chi-nese government in particular is accelerating their access to satel-lite technology in order to cope with natural and manmade disasterssuch as the recent Sichuan earthquake In terms of cellular backhaul,satellite is helping mobile service providers to reach those who havenot previously had access to telecommunications and helping themto communicate more easily with the outside world.

As modem and amplifier manufacturers innovate further and in-troduce new and more effective products to the market, it meansthat satellite services can be enjoyed by many more people and thosewho need it most. �