Inoperable Patent Claims: Satius v Samsung

Published 10 October 20266 minute read

Can a patent claim be perfectly clear and still invalid? On 1 October 2026 the Federal Circuit said yes. In Satius v Samsung, a claim to sending "electric or electromagnetic signals over air" covered one alternative that cannot work. The court held the claim clear, but not enabled.

The ruling matters to anyone drafting claims with alternatives joined by "or". This article explains the decision and compares inoperable embodiments in the United States, India, Europe and the United Kingdom.

Key points

In Satius Holding, LLC v Samsung Electronics Co., No. 2025-1446, the Federal Circuit held that a claim covering an impossible embodiment is not indefinite for that reason alone. Chief Judge Moore wrote for a panel with Judges Lourie and Hughes. The court decided the appeal on 1 October 2026.
The claims covered transmitting "electric or electromagnetic signals over air". Both sides accepted that transmitting electric signals over air is impossible.
The court still affirmed invalidity of claims 1, 11 and 18. The impossible alternative made the claims not enabled under 35 U.S.C. 112(a).
The ruling separates two questions. Clarity asks whether the scope is certain. Enablement asks whether everything inside that scope can be made and used.
India and Europe reach a similar result through sufficiency, support and, in India, section 3(a). Drafters should remove alternatives that cannot work before filing.

The patent and the dispute

Satius owned US Patent No. 6,711,385. It describes a coupler that matches the impedance of a wireless transmitter and receiver to the characteristic impedance of air. Claim 1 recites "a communications apparatus for transmitting electric or electromagnetic signals over air". Claims 11 and 18 depend from it.

Satius sued Samsung in the District of Delaware in 2018. The case was stayed during reexamination, in which the Patent Office rejected claim 1 and upheld claims 11 and 18. When the case resumed, the district court held all three claims indefinite. Its reason was that one claimed alternative, sending electric signals over air, is scientifically impossible.

The district court also doubted that the full scope of claim 1 could be enabled. It treated that defence as waived and did not decide it.

Impossible does not mean indefinite

The Federal Circuit began with claim construction. It read the claim to mean sending signals over air in electric form. It rejected Satius's reading that the signal could be converted before it left the device. In the court's words, transmitting signals over the air is not the same as transmitting signals to the air. The court also refused to redraft the claim to make it work.

It then applied the test in Nautilus v Biosig. A claim is indefinite if it fails to tell skilled persons the scope of the invention with reasonable certainty. The claim is read with the specification and prosecution history. The court said indefiniteness is not the same as impossibility. There is no rule that a claim covering inoperable embodiments is indefinite.

Here everyone understood what the claim covered. The impossible wording appeared in the claims and in the description. That distinguished Synchronoss v Dropbox, where the claims made no sense and the specification showed the inventor did not regard them as the invention.

Why the claims still failed

The court then decided enablement itself. The issue had been briefed, the facts were undisputed and a remand would serve no purpose.

The specification must enable the full scope of the invention as defined by the claims. That is the rule from Amgen v Sanofi (2023). The court held that this standard cannot be met when a claim expressly adds inoperable alternatives to its scope. It relied on earlier cases such as Liebel-Flarsheim and EMI Group.

Claim 1 covered both electric and electromagnetic transmission. The electric branch could not work at all. Quoting Amgen, the court said the more one claims, the more one must enable. The claims fell short. The court affirmed the judgment of invalidity on this ground.

What the ruling does not decide

It does not hold that every claim with an impossible feature is invalid. The result rests on an express alternative that the parties agreed could not work.
It does not rely on section 101 or the utility requirement. The court decided the case under section 112 alone, treating inoperability as an enablement question rather than a clarity question.
It does not change the Nautilus test. A claim must still be clear on its own terms. Clarity simply does not answer whether the claim works.

This sits alongside the full scope enablement theme in our note on Teva v Lilly and method of treatment claims. In both cases the claim scope, not the best example, decides the outcome.

India: sufficiency, fair basis and section 3(a)

An Indian examiner or court has several tools for the same problem. Section 3(a) of the Patents Act, 1970 excludes an invention that is frivolous or claims anything obviously contrary to well established natural laws. A claim to sending electric signals through air may draw that objection at the outset.

Section 10(4) requires the complete specification to describe the invention fully and particularly. Section 10(5) requires the claims to be clear and succinct and fairly based on the matter disclosed. After grant, section 64(1) allows revocation on several grounds. These include an invention that is not useful, an insufficient description, and a claim that is not clearly defined or not fairly based on the disclosure.

Indian practice often raises clarity, support and sufficiency together in one objection. Satius is a reminder to answer each one separately. Showing that the scope is clear will not cure a branch of the claim that cannot work.

Europe and the United Kingdom

At the EPO, clarity and support fall under Article 84 EPC. Sufficiency falls under Article 83. The EPO Guidelines deal with this in Part F, Chapter III, section 3. An invention that works contrary to established physical laws, such as a perpetual motion machine, is insufficiently disclosed. A claim may also fail Article 83 if it covers a range of embodiments that cannot be carried out.

The EPO allows some tolerance. Isolated non working embodiments do not always defeat a claim if the skilled person can recognise and avoid them. An express alternative that can never work is different. The usual remedy is amendment to delete it, provided the application as filed supports the narrower claim.

The UK applies a similar principle. In Regeneron v Kymab [2020] UKSC 27, the Supreme Court addressed claims to a range of products. The specification must enable the skilled person to make substantially all of them. A claim that reaches products the skilled person cannot make is insufficient.

Practical steps for applicants and patentees

Read each "or" in an independent claim as a separate claim. Ask whether every alternative can actually be made and used.
Remove alternatives that are only theoretically possible before filing. Keep them, if at all, in the description as context.
Prosecute the same family consistently in India, the US and at the EPO. An amendment made for one office should not leave an inoperable branch in another.
In litigation, test opposing claims for inoperable alternatives. Raise enablement early, so the point is not lost as waived.
For foreign applicants filing in India, address section 3(a) and fair basis in the first response, not only clarity.

For help aligning claims across offices, see our international patent support and guide to patent filing in India for foreign applicants.

Frequently asked questions

Is a patent claim indefinite if part of it is impossible?

Not for that reason alone in the US. In Satius v Samsung, the Federal Circuit held that impossibility and indefiniteness are different questions. A claim can be clear about its scope and still be invalid because part of that scope cannot work.

Can a patent claim cover embodiments that do not work?

It is risky. In the US, the specification must enable the full scope of the claim. The Federal Circuit held this cannot be met where a claim expressly includes inoperable alternatives. Europe and India apply similar sufficiency and support rules.

What is the difference between enablement and indefiniteness?

Indefiniteness asks whether a skilled person can tell with reasonable certainty what the claim covers. Enablement asks whether the patent teaches how to make and use everything the claim covers. A claim can pass the first test and fail the second.

Inoperable patent claims: clear but not enabled in Satius v Samsung