DCT
3:19-cv-14129
Just v. Aerodefense LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Tim Just (California)
- Defendant: Aerodefense LLC (New Jersey)
- Plaintiff’s Counsel: The Law Office Of JASON B. LATTIMORE, ESQ. LLC; Law Offices of Perry R. Clark
- Case Identification: 3:19-cv-14129, D.N.J., 06/21/2019
- Venue Allegations: Venue is based on Defendant being a New Jersey limited liability company with its principal place of business in the state, and allegations that it conducts substantial business and that at least a portion of the alleged infringement occurred in the district.
- Core Dispute: Plaintiff alleges that Defendant’s AirWarden drone detection system infringes a patent related to locating unmanned aerial vehicles (UAVs) by using multiple ground-based directional antennae to receive and process the UAV's radio frequency signals.
- Technical Context: The technology addresses the challenge of detecting and tracking small, commercially available drones, which can pose security threats to sensitive locations such as airports, prisons, and government facilities.
- Key Procedural History: The patent-in-suit, U.S. 10,089,887, was the subject of an ex parte reexamination requested after the complaint was filed. A Reexamination Certificate was issued on December 14, 2020, which amended the asserted independent claim 1. This amendment, which narrowed the claim language related to the use of directional antennae and the method of determining location, introduces the possibility of intervening rights defenses and will be central to the claim construction and infringement analysis.
Case Timeline
| Date | Event |
|---|---|
| 2015-03-06 | '887 Patent Priority Date |
| 2018-10-02 | '887 Patent Issue Date |
| 2019-03-13 | Alleged date Defendant became aware of '887 Patent |
| 2019-06-21 | Complaint Filing Date |
| 2020-01-31 | Reexamination Request Date for '887 Patent |
| 2020-12-14 | Reexamination Certificate Issue Date for '887 Patent |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,089,887 - "Drone Encroachment Avoidance Monitor"
- Patent Identification: U.S. Patent No. 10,089,887, "Drone Encroachment Avoidance Monitor," issued October 2, 2018.
The Invention Explained
- Problem Addressed: The patent describes conventional technologies like RADAR as being potentially unreliable for detecting small UAVs ("micro-UAVs"). It further notes that systems using single non-directional radio antennae cannot resolve the location of a micro-UAV, and even those with multiple non-directional antennae cannot reliably determine its elevation, creating significant security risks for sensitive areas like airports ('887 Patent, col. 2:40-63).
- The Patented Solution: The invention proposes a system using at least two spatially separated "scanning apparatuses," each equipped with one or more directional Radio Frequency (RF) antennae. These apparatuses are configured to receive the downlink RF signals continuously emitted by a target UAV ('887 Patent, Abstract). By determining the bearing and elevation of the signal from the perspective of each apparatus, the system can then process this angular data to triangulate and calculate a precise location of the UAV in three-dimensional space ('887 Patent, col. 3:21-29; Fig. 2).
- Technical Importance: The described technology provides a passive method to detect and locate small drones by homing in on their existing command-and-control signals, offering an alternative to active detection methods like radar that may be less effective against small, low-altitude targets ('887 Patent, col. 3:5-9).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1 of the '887 Patent (Compl. ¶10).
- The language of Claim 1 was amended during reexamination. The essential elements of the amended Claim 1 are:
- scanning a region of airspace with at least a first and a second scanning apparatus, the first comprising a first directional RF antenna and the second comprising a second directional RF antenna, with the apparatuses at different locations;
- receiving radio frequency signals emitted by a UAV at each of the directional RF antennae, where the signal is a downlink frequency from the UAV;
- determining, by comparing the first signal strength and the second signal strength, an angular relationship between the locations of the first and second directional RF antennae and the UAV; and
- processing the angular relationship to determine a first location of the UAV.
III. The Accused Instrumentality
Product Identification
- Defendant's "AirWarden" drone detection system (Compl. ¶10).
Functionality and Market Context
- The complaint alleges that the AirWarden system is designed for detecting and locating unmanned aerial vehicles (Compl. ¶12). It allegedly operates using a "plurality of ground data terminals" equipped with "radio frequency sensors" that are distributed around a facility (Compl. ¶13). The complaint includes a diagram from Defendant's website illustrating a four-sensor deployment around a central facility (Compl. p. 5).
- The system is alleged to function by detecting RF communications between a drone and its controller, specifically tracking common drone communication frequencies such as 2.4/5.8 GHz (Compl. ¶¶13-14).
- According to the complaint, the AirWarden system calculates the drone's location by using "the differences in the radio signal received by each ground data terminal" and "the signal strength and the spatial configuration of the ground data terminals" (Compl. ¶¶15-16).
- The final calculated location of the drone and its controller are then allegedly displayed on a map-based user interface (Compl. ¶18). The complaint provides a screenshot of this interface, showing a detected "Threat" on a satellite map (Compl. p. 6).
IV. Analysis of Infringement Allegations
- ’887 Patent Infringement Allegations
| Claim Element (from Amended Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| scanning a region of airspace with at least a first and a second scanning apparatus... comprising a first directional Radio Frequency (RF) antenna... [and] a second directional RF antenna... having different locations | The AirWarden system uses a "plurality of ground data terminals" with "radio frequency sensors located around a facility." | ¶13 | col. 4:48-51 |
| receiving radio frequency signals emitted by a UAV at each of the... directional RF antennae, wherein: a frequency... is a downlink frequency of the UAV, and the UAV is a source of the... signals | The AirWarden system "receives... signals associated with an unmanned aerial vehicle by tracking across a broad range of standard channels used for drone communications, including... 2.4/5.8 GHz." | ¶14 | col. 4:11-19 |
| determining, by comparing the first signal strength and the second signal strength, an angular relationship between the locations of the... RF antennae and the UAV | The system "uses the differences in the radio signal received by each ground data terminal to calculate the location" and "using the signal strength... generates data indicating a spatial relationship." | ¶15, ¶16 | col. 6:55-65 |
| processing the angular relationship... to determine a first location of the UAV | "As a result of the processing of the RF signals by the AirWarden system, the location of both the unmanned aerial vehicle and its controller are displayed on the user interface." | ¶18 | col. 7:45-53 |
- Identified Points of Contention:
- Scope Questions: A central issue will be whether the accused "radio frequency sensors" meet the amended claim's requirement of a "directional... antenna." The complaint does not explicitly allege the sensors use directional antennae. Because the patent specification contrasts the invention with systems using "non-directional antennae" (col. 2:53-56), the interpretation of "directional" and the factual nature of the accused hardware will likely be a primary point of dispute.
- Technical Questions: Amended Claim 1 recites a two-step process: (1) "determining... an angular relationship" by comparing signal strengths, and then (2) "processing" that relationship to find a location. The complaint alleges the AirWarden system "uses the differences in the radio signal... to calculate the location" (Compl. ¶15). The court may need to resolve whether the accused system performs the specific two-step method claimed or uses a different, more integrated computational method (e.g., multilateration) that does not first determine a discrete "angular relationship" as an intermediate step.
V. Key Claim Terms for Construction
The Term: "directional... antenna"
Context and Importance: This term is a critical limitation added during reexamination to distinguish the invention from prior art. The infringement analysis for the entire system depends on whether the accused "sensors" employ antennae that fall within the scope of this term.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent does not provide a formal definition. A party could argue the term encompasses any antenna that is not perfectly omni-directional. The specification's discussion of using an "array of adjacently placed directional antennae... to increase beamwidth" ('887 Patent, col. 4:48-51) may suggest that the precise characteristics of the directionality can vary.
- Evidence for a Narrower Interpretation: The specification repeatedly contrasts the invention with "non-directional antennae" ('887 Patent, col. 2:53-63) and describes embodiments where antennae rotate to "sweep for micro-UAVs and collect bearing and elevation data" ('887 Patent, col. 3:12-14). This may support an interpretation that "directional" implies an antenna with a focused beam used to determine a specific angle of arrival, rather than one with merely uneven gain.
The Term: "angular relationship"
Context and Importance: The claim requires the determination of an "angular relationship" as a specific step before the final location is processed. Whether the accused system calculates such an intermediate value is a key question for infringement.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The original claim language in the patent states the "angular relationship compris[es] a bearing and an elevation of the UAV relative to the scanning apparatuses" ('887 Patent, col. 11:21-24). This could be argued to cover any data set representing bearing and elevation, however derived.
- Evidence for a Narrower Interpretation: The detailed description links the "angular relationship" to a specific process of finding a "peak 5.8 GHz signal strength in the polar and azimuthal planes," yielding discrete angle values (θ₁ and φ₁) for each apparatus ('887 Patent, col. 6:55-65). A party could argue the term is limited to this method of determining specific angles of arrival from each sensor independently before triangulation.
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement, stating that Defendant "installed and assisted with its customers' direct infringement of the ‘887 patent by using the AirWarden system" (Compl. ¶11). This allegation points to affirmative acts intended to cause infringement by end-users.
- Willful Infringement: Willfulness is alleged based on Defendant having "knowledge of the ‘887 patent... at least as early as March 13, 2019" (Compl. ¶11). The complaint seeks enhanced damages for what it characterizes as "egregious conduct" (Compl., Prayer for Relief ¶C).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of technical evidence and claim scope: does the accused AirWarden system's "radio frequency sensor" technology constitute a "directional... antenna" within the meaning of the amended claims? The outcome may depend on whether discovery reveals the sensors to have focused-beam characteristics or if they operate in a manner more akin to omni-directional antennae.
- A second key question will be one of infringement methodology: does the accused system's algorithm for calculating a drone's location perform the discrete two-step process recited in amended Claim 1—first determining an "angular relationship" by comparing signal strengths, and then processing that data—or does it employ a different computational approach that sidesteps this claimed method?
- Finally, a significant legal issue will be the impact of the post-filing claim amendments. The court will likely have to address the doctrine of intervening rights, which could shield the Defendant from damages for any conduct occurring before the reexamination certificate issued if the amended claims are not "substantially identical" to the original claims.