Commercial satellite makers could help themselves and the space industry at large by collaborating on standardized technical requirements for Ka-band traveling wave tubes (TWTs), which owing to their complexity have become a pacing item on satellite broadband projects.
Currently, Ka-band TWTs must be tailored to the individual designs of the leading satellite makers, and because demand is relatively low they typically are made to order rather than available off the shelf — suppliers wait until a satellite maker wins a Ka-band contract before initiating a production run. Building a Ka-band TWT is a complicated, hands-on endeavor that takes about a year. When demand spikes, production lines can get backed up, and satellites fall behind schedule as a result.
The two main builders of Ka-band TWTs, L-3 Communications Electron Technologies of the United States and Thales Electron Devices of Germany, have been struggling of late to keep up with demand as more and more satellite operators place bets on this portion of the frequency spectrum, which is far less crowded than the C- or Ku-bands. L-3 and Thales could invest in new production capacity, but that would mean placing their own bet on a market about which some of the world’s biggest satellite operators still have doubts.
It’s tempting to say fortune favors the bold and challenge Thales and L-3 to take the risk. But that’s asking a lot in the current economic environment, especially since one prominent operator,, seems to have gotten off to a slow start with its TooWay Ka-band service.
There might be an easier way. According to L-3 and Thales, production bottlenecks could be avoided if the same basic Ka-band TWT design were compatible with multiple satellite brands. This would give the companies more flexibility to adjust TWT production flows according to the pace of various Ka-band projects under development, and perhaps even to stockpile some of the components. Standardization also would lower the cost of these components, savings that would be passed along to the customers in a competitive environment.
This would of course require the leading satellite makers to collaboratively tweak their designs to accommodate standardized Ka-band TWTs, something that may or may not be as simple as the component makers suggest. Certainly any such changes would come at a cost, and manufacturers would have to weigh that against the likely long-term benefits. There also is bound to be some sensitivity about sharing proprietary design information with competitors.
According to the TWT makers, satellite makers seem to get it and have made some progress toward accommodating standardized Ka-band TWTs. But they also expressed frustration at the slow pace of change.
Satellite makers should make a concerted effort to speed things along. Two U.S. companies, ViaSat and Hughes Network Systems, are sufficiently bullish on the domestic satellite broadband market to have invested in new high-throughput satellites costing hundreds of millions of dollars. Ka-band projects are springing up in other parts of the world, such as Australia. Moreover, as congestion grows in the traditional satellite broadcasting frequencies, companies and governments are bound to turn to the relatively underutilized Ka-band for new services.
Ka-band has some shortcomings compared with the C- and Ku-bands, such as greater sensitivity to heavy rainfall, and latency issues with geostationary-orbiting satellites in general make them less attractive than terrestrial links for broadband applications. In other words, the fledgling Ka-band services industry already has enough obstacles to wide-scale adoption. Delays incurred because certain components have to be uniquely tailored to a specific satellite platform design — a phenomenon more commonly associated with government-funded programs — should not have to be among them. If eliminating those delays helps the Ka-band market take off like many think it should, everybody benefits, from the operators down throughout their supplier chains.