Background
Raytheon Technologies (formerly United Technologies Corporation) owned a patent directed to a gas turbine engine with a fan drive gear system for high-bypass-ratio turbofan engines. The patent claimed specific parameters for power density and engine performance that represent advances in fuel efficiency. General Electric petitioned for inter partes review, arguing that the claims were obvious in view of a prior art reference called Knip.
The Knip reference was a NASA technical memorandum that described an aspirational design for an advanced turbofan engine with extremely aggressive performance targets. The problem was that the Knip reference acknowledged that achieving those targets would require composite materials that did not actually exist at the time — the reference explicitly stated that certain critical structural components required materials with properties beyond what any known composite could provide.
Raytheon submitted unrebutted expert testimony establishing that the Knip reference could not enable a skilled artisan to build the described engine because the required materials were hypothetical, not real. The PTAB nonetheless found the claims obvious over Knip. Raytheon appealed.
The Court’s Holding
The Federal Circuit reversed. The court held that a prior art reference that itself relies on materials or technologies that did not exist and could not be made by a skilled artisan cannot serve as an enabling disclosure for purposes of an obviousness analysis. Obviousness requires that a skilled artisan would have been motivated to combine teachings in the prior art and would have had a reasonable expectation of success. When the prior art reference relies on nonexistent materials to achieve its stated performance metrics, there is no reasonable expectation of success in following the reference’s approach.
The court emphasized that the key question is whether a skilled artisan could have actually built something within the scope of the challenged claims by following the teachings of the prior art, not whether an aspirational design might theoretically be imagined. Because General Electric had provided no evidence rebutting Raytheon’s showing that Knip’s critical structural components required nonexistent composite materials, the PTAB’s obviousness finding was unsupported by substantial evidence. The court reversed and entered judgment in Raytheon’s favor.
Key Takeaways
- A prior art reference that relies on non-existent materials or technologies to achieve the results it discloses cannot render patent claims obvious, because a skilled artisan would not have had a reasonable expectation of success following the reference’s approach.
- Unrebutted expert testimony showing that a prior art reference’s approach was not feasible with known materials or technologies must be credited — the PTAB cannot simply ignore unrebutted evidence of non-enablement.
- Aspirational or forward-looking prior art documents (like NASA technical memoranda forecasting future technology) must be carefully evaluated: they may describe inventions or designs that were not actually achievable at the time and thus cannot supply the reasonable expectation of success required for an obviousness finding.
- IPR petitioners should ensure that the prior art they rely on for obviousness actually enabled the claimed approach at the time of the invention, not just described it in theoretical terms.
Why It Matters
Raytheon v. GE is an important decision for industries — like aerospace, advanced manufacturing, and materials science — where prior art frequently consists of aspirational technical reports, academic papers, or government-funded research describing future goals rather than proven, executable designs. Such documents may describe parameters or configurations that were technologically impossible when written, yet appear on their face to anticipate or render obvious later patents.
The decision confirms that the enabling quality of prior art matters in an obviousness analysis: if a prior art reference could not be practiced by a skilled artisan because it relied on materials or methods that did not exist, it cannot serve as the foundation for an obviousness challenge. This is a meaningful safeguard for patentees whose innovations succeed precisely because they figured out how to make something that prior researchers had only imagined. It also underscores the importance of developing and presenting unrebutted expert evidence on enablement when challenging or defending patent claims in IPR proceedings.