DCT

7:26-cv-00231

Acoustic Array Tech LLC v. Apple Inc

Log In
Key Events
Amended Complaint
complaint Intelligence

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 7:26-cv-00231, W.D. Tex., 09/10/2026
  • Venue Allegations: Plaintiff alleges venue is proper in the Western District of Texas because Apple maintains regular and established places of business in the district, including corporate campuses and retail stores in Austin, and has committed acts of infringement there.
  • Core Dispute: Plaintiff alleges that Defendant’s smart products, including iPhones, iPads, and HomePods, infringe a patent related to MEMS-based acoustic microphone arrays used for beamforming.
  • Technical Context: The technology involves using arrays of miniature microphones and signal processing to directionally focus on sound sources, a technique critical for effective voice command recognition in modern consumer electronics.
  • Key Procedural History: The complaint alleges that the patent-in-suit, U.S. Patent No. 7,092,539, is co-owned with NASA. Plaintiff states that it engaged in pre-suit licensing discussions with Apple, which began with notice from NASA around January 2020. Plaintiff further alleges providing Apple with a notice letter in January 2022 and infringement claim charts in March 2022. The patent was assigned to Plaintiff by the University of Florida Research Foundation in November 2024. The patent expired in June 2024 after a 939-day term adjustment.

Case Timeline

Date Event
2000-11-28 ’539 Patent Priority Date
2006-08-15 ’539 Patent Issue Date
2019-09-10 Earliest alleged infringing product launch (iPhone 11)
2020-01-06 Alleged date of NASA notice to Apple during licensing discussions
2022-01-14 Plaintiff sends notice letter to Apple
2022-03-08 Plaintiff provides infringement claim charts to Apple
2024-06-24 ’539 Patent Expiration Date
2024-11-11 University of Florida Research Foundation assigns patent rights to Plaintiff
2026-09-10 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,092,539 - "MEMS based acoustic array"

  • Patent Identification: U.S. Patent No. 7,092,539, titled “MEMS based acoustic array,” issued on August 15, 2006 (the “’539 Patent”).

The Invention Explained

  • Problem Addressed: The patent’s background section describes the difficulty of measuring and localizing aeroacoustic noise sources, such as those from aircraft, using traditional microphone systems in environments like wind tunnels (ʼ539 Patent, col. 1:26-45). These systems suffer from poor signal-to-noise ratios, and scaling them up to larger, more effective arrays is limited by high costs, complex data handling, and lack of mobility (ʼ539 Patent, col. 2:5-12).
  • The Patented Solution: The invention proposes a modular and cost-effective acoustic array built on a printed circuit board (PCB). The PCB holds multiple packages, each containing a microelectromechanical systems (MEMS) microphone (ʼ539 Patent, abstract). A signal processor on the board implements a technique known as beamforming, which selectively weights and delays the signals from each microphone to create a directionally sensitive response (ʼ539 Patent, col. 7:56-61). This process enhances the desired signal while rejecting background noise, allowing for precise sound source localization (ʼ539 Patent, col. 8:5-9).
  • Technical Importance: This approach enabled the creation of a "high-speed, cost effective, modular, array measurement system" that could provide near real-time output, a significant advantage over prior art systems that required extensive post-processing Compl. ¶25 '539 Patent, col. 2:13-16

Key Claims at a Glance

  • The complaint’s infringement allegations focus on independent claim 1 Compl. ¶36
  • The essential elements of Claim 1 are:
    • A printed circuit board (PCB) array responsive to aeroacoustic waves.
    • The PCB has a first surface and an opposing second surface.
    • A plurality of sockets are distributed over the first surface of the PCB.
    • A plurality of microphone packages are received in the sockets, with each package containing at least one MEMS-style microphone that includes a semiconductor substrate, a cavity, a diaphragm, and a vent channel in fluid communication with the cavity and surrounding atmosphere.
    • At least one signal processor on the PCB is coupled to the microphone packages, "beamforming" the received signals and outputting a combined signal.
  • The complaint alleges infringement of "one or more claims" but its detailed analysis is limited to Claim 1 Compl. ¶36

III. The Accused Instrumentality

Product Identification

  • The complaint identifies a wide range of Apple products, including the iPhone 11 through 17 series, various iPad models, the HomePod (2nd generation), and the HomePod mini (collectively, the "Accused Products") Compl. ¶3

Functionality and Market Context

  • The Accused Products are described as "smart" devices that utilize voice control Compl. ¶3 The complaint alleges these products implement directional acoustic arrays with multiple microphones to perform beamforming (Compl. ¶¶2-3). This functionality is allegedly used for features such as "far-field Siri" voice recognition and "sound recognition for smoke and carbon monoxide alarm sounds," which allow the devices to locate and process sounds from a distance, even in noisy environments Compl. ¶42 The complaint uses the HomePod Mini as an exemplary accused product for its detailed infringement analysis Compl. ¶33 A screenshot from Apple's website is included to show the "Four-microphone design for far-field Siri" Compl. p. 18

IV. Analysis of Infringement Allegations

’539 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A printed circuit board array responsive to aeroacoustic waves, comprising: a. a printed circuit board having a first surface and an opposing second surface; The Apple HomePod Mini contains a "Main Board," which is a printed circuit board (PCB) with first and second opposing surfaces that is responsive to acoustic waves. ¶36; ¶37 col. 18:15-18
b. a plurality of sockets distributed over the first surface of the printed circuit board; The Main Board includes a plurality of sockets on its first surface, as shown in a teardown photograph. A visual from the complaint identifies the location of these sockets. ¶37 col. 18:19-20
c. a plurality of microphone packages, wherein each microphone package is received in a corresponding socket and contains at least one microphone...each of said microphones including a semiconductor substrate, a cavity formed in said substance, a diaphragm covering said cavity, and a vent channel in fluid communication with said cavity and an atmosphere surrounding said array; The sockets receive multiple microphone packages. A complaint visual shows these packages on the board Compl. p. 15 Each package allegedly contains a MEMS microphone with a semiconductor substrate, a cavity, a diaphragm, and a vent channel, as shown in microscopy images. ¶38; ¶39; ¶40 col. 18:21-29
d. at least one signal processor disposed on said circuit board...said processor beamforming signals received from said plurality of microphone packages and outputting a combined signal therefrom. The Main Board includes a signal processor (identified as a Conexant ADC chip) that allegedly performs beamforming on signals from the microphones to enable features like "far-field Siri." Apple's own product specifications confirm a "Four-microphone design for far-field Siri." ¶41; ¶42 col. 18:30-33
  • Identified Points of Contention:
    • Scope Questions: A central question may be the interpretation of the term "aeroacoustic waves." The patent’s background is exclusively focused on aerospace applications, such as measuring noise from aircraft in wind tunnels (ʼ539 Patent, col. 1:26-53). The court will have to determine whether this term should be narrowly construed to its original context or interpreted more broadly to cover any sound wave traveling through air, which would be necessary to read on the Accused Products' function of capturing human speech and other household sounds.
    • Technical Questions: Claim 1(c) requires a "vent channel in fluid communication with said cavity and an atmosphere surrounding said array." The complaint provides teardown and microscopy images purporting to show this structure Compl. ¶¶39-40 The infringement analysis may turn on whether the accused microphone’s structure meets this "fluid communication" limitation and performs the pressure equilibration function described in the patent (ʼ539 Patent, col. 9:31-43).

V. Key Claim Terms for Construction

  • The Term: "aeroacoustic waves"

    • Context and Importance: This term, found in the preamble and claim 1, is critical. A narrow construction tied to the patent's disclosed field of use (aerodynamics) could support a non-infringement argument, as the accused products are not used in that context. A broad construction covering general sound in air would favor the plaintiff's allegations. Practitioners may focus on this term because its construction could be dispositive of the entire case.
    • Intrinsic Evidence for a Broader Interpretation: The patent’s abstract refers more generally to a "combination responsive to an acoustic wave" (ʼ539 Patent, abstract). The specification also explains beamforming in general terms applicable to any acoustic wave, not just those from an aircraft (ʼ539 Patent, col. 7:56-61).
    • Intrinsic Evidence for a Narrower Interpretation: The "Background of the Invention" section is entirely dedicated to the problems of measuring "aircraft noise" and characterizing "aeroacoustic sources" in "wind tunnels" (ʼ539 Patent, col. 1:26-45). The consistent use of "aeroacoustic" in this specific context suggests the inventors may have intended a meaning limited to that technical field.

  • The Term: "beamforming signals"

    • Context and Importance: Claim 1(d) requires the signal processor to perform "beamforming." The complaint equates this with Apple's "far-field Siri" technology Compl. ¶42 The dispute may hinge on whether the specific algorithms used by Apple technically constitute "beamforming" as the term is used and described in the ʼ539 Patent.
    • Intrinsic Evidence for a Broader Interpretation: The patent provides a high-level functional definition, stating that "Beamforming provides the array with a directional response, which is electronically 'steered' in space" (ʼ539 Patent, col. 7:60-61). This definition may be broad enough to encompass the functionality of Apple's far-field voice recognition technology.
    • Intrinsic Evidence for a Narrower Interpretation: The specification provides "delay-and-sum beamforming" as an example of the process (ʼ539 Patent, col. 8:5-9). A defendant could argue that the term should be limited to that specific method or closely related techniques, potentially distinguishing it from more modern and computationally complex methods used in the accused devices.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement under 35 U.S.C. § 271(b), asserting that Apple actively encourages customers to use the infringing features through advertising, product support documentation, and user manuals for voice-controlled functionalities Compl. ¶43
  • Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge of the ʼ539 Patent. The alleged knowledge stems from licensing discussions initiated by NASA around January 6, 2020, a specific notice letter from the Plaintiff on January 14, 2022, and the subsequent provision of infringement claim charts on March 8, 2022 Compl. ¶44 The plaintiff argues that Apple's continued sales despite this knowledge constitute willful infringement, warranting enhanced damages Compl. ¶46

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of definitional scope: can the term "aeroacoustic waves," which is rooted in the patent’s explicit context of aerospace and wind-tunnel testing, be construed to cover the ordinary sound waves, such as human speech, captured by the accused consumer electronic devices?
  • A second central question will be one of technical interpretation: does the signal processing used in Apple’s products for features like "far-field Siri" perform the function of "beamforming" as required by Claim 1, or is there a material difference between Apple's modern algorithms and the "delay-and-sum" methods described in the patent's specification?
  • Finally, the case may present a significant damages question related to willfulness, turning on the evidence of Apple's state of mind following pre-suit communications with both NASA and the Plaintiff regarding the ʼ539 Patent.