Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. v. Sirius XM Radio Inc.

CourtDistrict Court, D. Delaware
DecidedMarch 24, 2026
Docket1:17-cv-00184
StatusUnknown

This text of Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. v. Sirius XM Radio Inc. (Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. v. Sirius XM Radio Inc.) is published on Counsel Stack Legal Research, covering District Court, D. Delaware primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. v. Sirius XM Radio Inc., (D. Del. 2026).

Opinion

IN THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF DELAWARE

FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V., 1:17CV184

Plaintiff, MEMORANDUM & ORDER vs.

SIRIUS XM RADIO INC.,

Defendant.

This matter is before the Court after a November 4, 2025, bench trial. This is a patent dispute involving several patents covering satellite radio technology.1 The Court previously entered summary judgment in favor of Defendant, Sirius XM Radio Inc. (“SXM”), because Plaintiff’s, Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. (“Fraunhofer”), infringement claims were barred by equitable estoppel. See D.I. 816. Specifically, Fraunhofer figuratively sat on its hands for years while SXM used its patented technology. On appeal, the Federal Circuit agreed summary judgment was appropriate on two elements of the equitable estoppel defense: (1) Fraunhofer’s conduct was misleading and (2) SXM was prejudiced by Fraunhofer’s misleading conduct. Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V. v. Sirius XM Radio Inc., 138 F.4th 1373, 1378–80, 1382–83 (Fed. Cir. 2025). But the panel concluded there was a dispute of material fact concerning SXM’s reliance. Id. at 1380– 82. On remand, the Court took the Federal Circuit’s roadmap, bifurcated the issue of equitable estoppel, and scheduled a bench trial on the reliance element.

1 U.S. Patents 6,314,289, 6,931,084, 6,993,084, and 7,061,997. I. BACKGROUND The following background is taken from this Court’s prior order, D.I. 836: This is a patent dispute in the world of satellite radio. Fraunhofer, a German company, developed various inventions related to multicarrier modulation technology. Fraunhofer, 138 F.4th at 1376. SXM used this technology in its commercial satellite radio product. Id.

SXM—through its predecessor in interest XM—began using Fraunhofer’s technology in the late 1990s. Id. Through a series of mergers, bankruptcies, and licensing agreements, SXM continues to use that technology today. Id. at 1376–77.

SXM’s use of Fraunhofer’s technology was not preordained. Back in 2008, SXM faced a branching path between two radio systems that required different hardware: a high band system that used Fraunhofer’s technology and a low band system that did not. Id. at 1377. In part, believing it had a license to use the patented technology, SXM opted for the high band system and abandoned the low band system over the next few years. Id.

According to Fraunhofer, SXM got it wrong. Without getting into unnecessary detail, Fraunhofer believes SXM’s sublicense was terminated in 2010 bankruptcy proceedings. Id. Basically, Fraunhofer believes SXM has been infringing its patents since at least 2010. Id.

Fraunhofer did not raise this issue with SXM in 2010. Id. Instead, it waited five years to spring its infringement theory on SXM. Id. After negotiations failed, it sued in federal court. After some procedural twists and turns, the parties moved for summary judgment. The Court entered summary judgment in favor of SXM on its equitable estoppel theory. Id. Specifically, it concluded there was no dispute of material fact that: “(1) [Fraunhofer] engage[d] in misleading conduct that” led SXM “to reasonably infer that [Fraunhofer] [did] not intend to assert its patent against” SXM; (2) SXM “relie[d] on that conduct; and (3) as a result of that reliance, [SXM] would be materially prejudiced if [Fraunhofer] [was] allowed to proceed with its infringement action.” See Id. (quoting Ferring B.V. v. Allergan, Inc., 980 F.3d 841, 853 (Fed. Cir. 2020)) (elements of equitable estoppel).

On appeal, the Federal Circuit reversed but did not disclaim the Court’s analysis wholesale. It “agree[d] with the district court's conclusion that Fraunhofer's more-than-five-year silence in asserting infringement, in light of its clear knowledge of that infringement, rose to the level misleading conduct.” Fraunhofer, 138 F.4th at 1380. And, “should SXM be able to establish at trial that it relied on Fraunhofer's misleading conduct in connection with its decision to migrate to the accused high-band system as opposed to the non-infringing low-band alternative, then it has adequately established that it was prejudiced by that silence.” Id. at 1382–83. But, citing other business reasons for migrating to high band, the panel concluded there was a fact dispute about whether SXM relied on Fraunhofer’s misleading conduct—precluding summary judgment. Id. at 1381. Basically, “[t]here may have been sufficient circumstantial evidence to permit a factfinder to find reliance but the existing record does not compel such a finding.” Id. at 1381–82.

The Federal Circuit denied the parties’ en banc petitions, issued its mandate, and now this case is back with the Court. The Court has exclusive jurisdiction over this dispute under 28 U.S.C. § 1338.

Id. at 1–3.

On November 4, 2025, the Court held a bench trial to determine whether SXM relied on Fraunhofer’s misleading silence for purposes of equitable estoppel. The following constitutes the Court’s findings of fact and conclusions of law pursuant to Fed. R. Civ. P. 52(a). II. FINDINGS OF FACT A. The Parties Fraunhofer is a non-profit research organization existing under the laws of the Federal Republic of Germany. D.I. 860 at 4, ¶ 1. Fraunhofer has developed and patented various inventions relating to multicarrier modulation (“MCM”) technology. That technology is used for Digital Audio Radio Service (“DARS”), otherwise known as satellite radio. D.I. 860 at 5, ¶ 13; Fraunhofer, 138 F.4th at 1376. SXM is a limited liability company organized and existing under the laws of Delaware with its principal place of business at 1221 Avenue of the Americas, New York, New York 10020. D.I. 860 at 4, ¶ 2; Fraunhofer, 138 F.4th at 1376. SXM is a satellite radio provider in the United States that broadcasts hundreds of channels as part of its satellite radio service, sells and supplies satellite radio receivers directly to consumers,

and works with automobile manufacturers and others involved in the automobile manufacturing process to have satellite radio receivers installed in new vehicles. D.I. 860 at 5–6, ¶ 14; Fraunhofer, 138 F.4th at 1376. B. Witnesses a. Paul Krayeski Mr. Krayeski is the Vice President of the Innovation Center Development Team at SXM. D.I. 904 at 18. He has worked at SXM and its predecessor XM for about 20 years. Id. Mr. Krayeski is “responsible for the development of the receiver technology which ranges from the embedded chipset development as well as libraries.” Id. He also heads

a team in charge of “OEM module designs and production test systems.” Id. Mr. Krayeski was involved in “negotiating any agreements that relate to receiver technology that we [SXM] need to license.” Id. As a result, Mr. Krayeski was involved in negotiating several agreements with Fraunhofer (and others) from the time he joined XM in 2005. Id. at 30–31. Mr. Krayeski also was “extensively involved” in discussions about which satellite radio broadcast system SXM would migrate to after the 2008 merger of Sirius and XM: XM’s high-band system or Sirius’s low-band system. Id. at 19. He “was the main management contact for the [legacy] XM system” and worked with his counterpart on the Sirius side. Id. at 20. They “built technical organizations together to conduct a very exhaustive analysis of the two technologies to try to determine if there was a technology advantage of one system versus the other.” Id.

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Bluebook (online)
Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. v. Sirius XM Radio Inc., Counsel Stack Legal Research, https://law.counselstack.com/opinion/fraunhofer-gesellschaft-zur-forderung-der-angewandten-forschung-ev-v-ded-2026.