Samsung Electronics Co Ltd v. NuCurrent Inc

1. Case Identification

• Patent #: 9,941,729
• Filed: June 19, 2019
• Petitioner(s): Samsung Electronics Co., Ltd.
• Patent Owner(s): Nucurrent, Inc.
• Challenged Claims: 1-9, 11-19, 21, and 23-26

2. Patent Overview

• Title: Multi-Mode Antenna
• Brief Description: The ’729 patent relates to a wireless power antenna with a compact design comprising multiple inductor coils electrically connected in series. This single-coil structure is intended to enable tuning for multiple antenna frequencies, improving on prior art multi-coil antennas that had a larger footprint.

3. Grounds for Unpatentability

Ground 1: Claims 1, 5-8, 12-14, 16-18, 21, and 23 are obvious over Riehl.

• Prior Art Relied Upon: Riehl (Application # 2014/0035383).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Riehl discloses all features of the challenged claims. Riehl teaches a dual-mode wireless power receiver with two inductor coils (L2 and L3) connected in series on a printed circuit board (PCB) in a concentric, planar arrangement. Petitioner mapped Riehl’s inner and outer coils to the claimed "first coil" and "second coil," respectively. The ability to operate at two distinct frequencies (a low-frequency mode around 100 kHz and a high-frequency mode at 6.78 MHz) was argued to satisfy the claim requirement for different resonant frequencies. Petitioner contended that the limitation requiring the gap between the two coils (the "third gap") to be larger than the gaps between the turns within each coil (the "first" and "second" gaps) is inherently suggested by Riehl's figures and would have been obvious to a person of ordinary skill in the art (POSITA) to minimize mutual inductance, a known design consideration.
  • Motivation to Combine (for §103 grounds): This ground is based on a single reference. However, for the gap-size limitation, Petitioner asserted a POSITA would be motivated to ensure the coils behave as individual inductors rather than a transformer by increasing the spacing between them, which was a known technique for a predictable result.
  • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success in implementing the gap sizing, as it involved applying a well-understood principle to achieve the predictable outcome of reduced mutual inductance.

Ground 2: Claims 3, 4, 9, 14, and 26 are obvious over Riehl in view of Riehl IEEE.

• Prior Art Relied Upon: Riehl (Application # 2014/0035383) and Riehl IEEE (an IEEE publication from March 2015).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed claims requiring features not explicitly detailed in Riehl, such as a conductive wire comprising "two or more filars electrically connected in parallel" (claim 3). Petitioner argued that Riehl IEEE, a publication by the same lead inventor as the Riehl application, expressly discloses using a multi-conducting-layer coil with parallel traces for the outer coil of a similar dual-mode receiver. This technique was used to increase the coil's quality factor (Q), a desirable characteristic for efficient power transfer.
  • Motivation to Combine (for §103 grounds): A POSITA implementing Riehl's dual-mode receiver would combine its teachings with Riehl IEEE. Both references address the same technical problem, share an inventor, and describe similar dual-mode systems. Riehl IEEE provides an explicit, advantageous modification (parallel filars for high Q) that directly improves the base system disclosed in Riehl.
  • Expectation of Success (for §103 grounds): There would be a high expectation of success, as this combination represents the application of a known improvement technique from a nearly identical system to achieve the well-understood and predictable benefit of an increased Q-factor.

Ground 3: Claims 1, 2, 5-8, 12-14, 16-19, 21, 23, and 25 are obvious over Riehl in view of Yu.

• Prior Art Relied Upon: Riehl (Application # 2014/0035383) and Yu (Korean Application # 10-2013-0045307).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground presented an alternative basis for the obviousness of claim 1 and its dependents, focusing on the gap-spacing limitation. Petitioner argued that to the extent Riehl alone was found not to teach that the gap between the coils is greater than the gaps between the turns, the combination with Yu rendered it obvious. Yu explicitly discloses a concentric two-coil antenna for wireless charging where the gap between the inner and outer coils is 3.0 mm, while the gaps between the turns within the coils are much smaller (0.1 mm and 0.2 mm). Yu also discloses a gap range of 2.0 mm to 9.0 mm between coils, which overlaps the range recited in claim 19.
  • Motivation to Combine (for §103 grounds): A POSITA would combine the references to solve the known problem of mutual interference between concentric coils in Riehl. Yu teaches that its specific gapping strategy serves to "prevent loss of performance due to mutual interference." This provides an express reason to modify Riehl's design by applying Yu's dimensional teachings to achieve the predictable result of improved coil independence and performance.
  • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success in applying Yu's clear dimensional teachings to Riehl's similar concentric coil structure to predictably reduce mutual inductance.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Riehl with Kanno (Application # 2011/0241437) to teach a variable wire width, with Sung (Application # 2012/0274148) to teach a flexible polyimide substrate, and with Kazuya (JP Publication No. 2013-93429) to teach specific inductance ranges. Further grounds combined Riehl and Yu with Riehl IEEE, Kanno, Sung, or Kazuya.

4. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-9, 11-19, 21, and 23-26 of the ’729 patent as unpatentable.