Traveling-wave tubes (TWTs) are a type of vacuum tube critical for many high-performance applications, including deep space missions, satellites and electronic warfare. For decades, their ability to efficiently amplify high-frequency signals across wide bandwidths has ensured reliable, long-range communication and radar capabilities.
However, despite their proven performance, TWTs require highly specialized and labor-intensive manufacturing processes due to their complex design and the precision needed for reliable operation: Producing a single unit often requires 12 to 18 months. This manufacturing bottleneck has constrained supply, increased costs and limited broader adoption in both defense and commercial markets.
Supported by Small Business Innovation Research (SBIR) program funding at DARPA, Elve – a deep-tech hardware manufacturing startup – developed a new approach to TWT manufacturing. DARPA’s SBIR programs guide small businesses through a structured three-phase process to advance their innovations: feasibility demonstrations; full-scale research and development; and transition to commercialization. This framework enables them to move from concept to deployment, ensuring significant impact on both national security and commercial markets.
Through its participation in the SBIR program, Elve developed a novel additive manufacturing process called Layered Additive Multi-Material Manufacturing – Digitized (LAM3D). This breakthrough reduces TWT production times from over a year to just a matter of weeks.
A paradigm-shift in TWT production and application
Compared to current methods, the approach developed by Elve during its DARPA program represents a leap forward. The LAM3D process combines additive manufacturing techniques with advanced inspection and alignment features to fabricate TWT circuits with unprecedented speed and precision. This not only shortens production timelines but also reduces costs – enabling rapid prototyping and high-yield manufacturing.
Elve also demonstrated the ability to generate and optimize TWT designs in under two hours – a process that normally requires significant engineering effort and time – across Q-band (33–50 GHz), V-band (40–75 GHz) and E-band (60–90 GHz) frequencies. These frequency bands are critical for advanced communication and radar technologies, requiring precise engineering to operate effectively.
A model for DARPA-supported innovation
As part of its commercialization strategy, Elve participated in DARPA’s Embedded Entrepreneur Initiative (EEI), which connects agency-funded innovators with top-tier business minds to help them with their commercialization efforts. Through EEI, Elve hired an entrepreneur with specialized expertise to help refine its market strategy, conduct in-depth research and engage industry stakeholders. This effort provided critical insights into customer needs and market positioning and ultimately helped Elve expand its customer base. Additionally, Elve raised $15M in Series A funding, enabling the company to open a commercial manufacturing facility.
Building on the success of its DARPA work, Elve has since expanded the capabilities of its LAM3D technology to manufacture circuits at frequencies above 200 GHz, pushing the boundaries of TWT performance to the cutting edge of current RF applications. As future defense and commercial systems demand even higher frequencies to support emerging applications – such as next-generation communications, advanced sensing and energy beaming for sustainable power transfer – Elve’s innovation positions TWT technology to meet these evolving needs.
Elve’s rapid progress exemplifies how DARPA’s integrated approach – pairing SBIR-driven technological innovation with EEI’s commercialization support – fosters transformative solutions from small businesses, from concept to market. Through SBIR investments, DARPA provides critical early-stage funding to drive high-risk, high-reward research and development, enabling companies like Elve to push the boundaries of what’s possible.
Crucially, programs like EEI then help bridge the gap between innovation and market impact by equipping these companies with the strategic business expertise needed to navigate commercialization and scale their solutions.