Case Study
Major European Teleport — GaN SSPA Fleet Modernisation for Broadcast Uplink
How Celestia TTI’s GaN solid state power amplifiers replaced an ageing TWTA fleet, delivering higher efficiency, lower operating costs, and uninterrupted 24/7 broadcast uplink operations.
The Challenge
A leading European satellite teleport operator serving major broadcast networks across the continent faced a critical infrastructure challenge. Their fleet of travelling wave tube amplifiers (TWTAs), the backbone of Ku-band uplink operations for over a decade, was approaching end of life. The ageing TWTAs presented multiple operational risks: increasing failure rates requiring costly tube replacements (each TWT costing EUR 15,000–25,000 with 12–16 week lead times), degrading linearity affecting signal quality for modern DVB-S2X waveforms, and electricity consumption that represented the single largest operational expenditure at the facility.
The teleport operated 24 uplink chains serving DTH (Direct-to-Home) television platforms, contribution feeds for live sports and news, and occasional-use capacity for outside broadcast vehicles. Any uplink interruption — even momentary — would affect millions of viewers across multiple countries. The replacement solution had to deliver seamless transition with zero on-air disruption during the migration period.
Additionally, the operator’s roadmap included expansion into High Throughput Satellite (HTS) services requiring operation across multiple narrowband carriers with stringent linearity requirements — a capability that the existing TWTA fleet could not economically support without significant back-off penalties.
Why Celestia TTI
Celestia TTI was selected following a competitive evaluation against three other SSPA manufacturers and the option of TWTA fleet replacement. The key differentiators that secured the contract were:
- ▸ GaN Technology Leadership: Celestia TTI’s GaN SSPA platform delivers 750 W saturated output power in Ku-band from a single unit — the highest power density available in solid state, eliminating the need for combining multiple lower-power amplifiers.
- ▸ Broadcast-Proven Reliability: Over 2,000 SSPAs deployed at teleport facilities worldwide with documented MTBF exceeding 100,000 hours — ten times the typical TWTA tube lifetime.
- ▸ Graceful Degradation: GaN SSPA architecture with internal module redundancy ensures that a single device failure results in only a minor power reduction rather than complete uplink loss, unlike TWTA technology where tube failure is catastrophic.
- ▸ DVB-S2X Optimisation: Factory-configurable linearisation achieving <-45 dBc IMD3 performance, enabling operation with modern waveforms at significantly reduced output back-off compared to TWTAs.
The Solution
Celestia TTI delivered a turnkey SSPA fleet replacement programme, comprising 28 high-power GaN SSPAs across Ku-band and DBS-band frequencies, complete with monitoring and control infrastructure, redundancy switching, and on-site commissioning support.
High-Power Ku-Band GaN SSPAs
The core of the deployment consisted of Celestia TTI’s flagship Ku-band SSPA units delivering 750 W saturated output power across 13.75–14.5 GHz. The GaN power amplifier modules utilise a corporate combining architecture with hot-swappable power modules, enabling field maintenance without removing the unit from service. Each SSPA includes integrated upconversion from L-band IF, eliminating external upconverter units and reducing the overall RF chain complexity.
DBS-Band Extensions
For the DTH uplink chains operating in the DBS frequency allocation (17.3–18.1 GHz), Celestia TTI provided dedicated DBS-band SSPAs rated at 500 W. These units share the same mechanical footprint and monitoring interface as the Ku-band models, simplifying spare parts inventory and operator training.
1+1 Redundancy with Automatic Switchover
Critical broadcast uplink chains were configured in 1+1 redundant pairs with Celestia TTI’s automatic changeover system. The switchover latency of less than 50 milliseconds — well within the error correction capability of DVB-S2X receivers — ensures that no viewer-perceptible disruption occurs during a failover event. The system continuously monitors output power, reflected power, temperature, and current draw, triggering automatic switchover on any parameter exceedance.
Centralised Monitoring & Control
All 28 SSPAs were integrated into the teleport’s existing monitoring infrastructure via SNMP v3 and serial interfaces. Celestia TTI provided a customised monitoring dashboard enabling operators to view real-time status, historical performance trends, and predictive maintenance alerts for the entire SSPA fleet from a single screen.
Results & Impact
Energy Cost Savings
The GaN SSPAs achieved 35% wall-plug efficiency compared to the TWTAs’ 18–22%, reducing annual electricity consumption by over 180 MWh. Combined with elimination of tube cooling requirements, total energy-related OPEX decreased by 60%, delivering payback on the capital investment within 30 months.
Uplink Availability
Over 18 months of operation, the SSPA fleet achieved 99.99% aggregate uplink availability — exceeding the 99.95% SLA commitment. Zero unplanned broadcast interruptions were recorded, compared to an average of 4.2 TWTA-related outage events per year under the previous architecture.
Signal Quality
The superior linearity of GaN SSPAs enabled the operator to transition from DVB-S2 to DVB-S2X modulation on multiple carriers, achieving 15–20% bandwidth efficiency gains. This freed up transponder capacity equivalent to approximately EUR 800,000 annually in lease savings.
Maintenance Simplification
Elimination of TWT tube replacements (previously 8–12 per year at EUR 15,000–25,000 each) and the hot-swappable module architecture reduced annual maintenance costs by over 75%. The SSPA fleet requires no scheduled maintenance beyond annual filter cleaning.
Technical Specifications Summary
| Parameter | Ku-Band SSPA | DBS-Band SSPA |
|---|---|---|
| Frequency Range | 13.75–14.5 GHz | 17.3–18.1 GHz |
| Saturated Output Power | 750 W | 500 W |
| Efficiency | 35% | 32% |
| IMD3 | <-45 dBc | <-43 dBc |
| Gain Flatness | ±0.75 dB | ±0.75 dB |
| Redundancy | 1+1 with <50 ms switchover | |
| MTBF | >100,000 hours | |
Related Celestia TTI Solutions
SSPA & BUC Portfolio
Complete range of GaN and GaAs solid state power amplifiers from C-band to Ka-band.
Ku-Band SSPAs
High-power Ku-band GaN SSPAs for broadcast uplink, VSAT, and SNG applications.
Broadcast Solutions
Turnkey RF solutions for satellite teleports, DTH, contribution, and SNG operations.
Planning a TWTA-to-SSPA Migration?
Celestia TTI provides complete fleet replacement programmes with zero on-air disruption, including site survey, installation, commissioning, and training.