Volkswagen Group Of America Inc v. Arigna Technology Ltd

1. Case Identification

• Case #: IPR2021-01263
• Patent #: 7,397,318
• Filed: July 16, 2021
• Petitioner(s): Volkswagen Group of America, Inc.
• Patent Owner(s): Arigna Technology Limited
• Challenged Claims: 1-2

2. Patent Overview

• Title: Voltage-Controlled Oscillator
• Brief Description: The ’318 patent discloses a voltage-controlled oscillator (VCO) designed to correct for variations in oscillation frequency caused by temperature changes. The technology involves a temperature compensation circuit that shifts the voltage range applied across a variable-capacitance element to stabilize the oscillator's output frequency.

3. Grounds for Unpatentability

Ground 1: Claim 1 is obvious over Kubo in view of Webb.

• Prior Art Relied Upon: Kubo (Patent 4,751,475) and Webb (Patent 3,325,749).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kubo, which the ’318 patent acknowledges is analogous to the "conventional art," disclosed nearly all elements of claim 1, including the core VCO, bias circuits, and a temperature compensation circuit using a transistor. Petitioner asserted, however, that Kubo failed to teach a transistor with a grounded collector and a negative voltage supply. Webb allegedly supplied these missing elements by disclosing a temperature-compensating voltage regulator circuit that explicitly used a transistor with a grounded collector and was powered by a negative (-24V) voltage source.
  • Motivation to Combine: A POSITA would combine Webb's circuit configuration with Kubo's VCO to improve temperature stability, a known problem in the art. Applying Webb's teachings would allow for shifting the voltage level down, increasing the reverse bias across Kubo's variable-capacitance element, and thereby compensating for negative temperature coefficients in a predictable manner.
  • Expectation of Success: Petitioner contended the combination involved the simple substitution of known elements for their intended purpose. Webb's disclosure that its teachings are applicable to circuits with either positive or negative power supplies would have provided a POSITA with a clear expectation that incorporating its negative-supply, grounded-collector design into Kubo would function as expected.

Ground 2: Claim 1 is obvious over Kubo in view of Cubert.

• Prior Art Relied Upon: Kubo (Patent 4,751,475) and Cubert (Patent 3,654,486).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented Cubert as an alternative to Webb for teaching the missing elements in Kubo. Petitioner argued Cubert disclosed a transistor feedback circuit where the transistor’s collector was connected to ground via a resistor and its emitter was connected to a negative voltage source (-VEE). This directly taught the grounded-collector and negative-supply configuration that claim 1 adds to the conventional art of Kubo.
  • Motivation to Combine: The motivation was identical to Ground 1: improving the temperature stability of the VCO. Cubert's circuit provided a well-understood method for biasing a transistor that would predictably increase the reverse bias on the variable-capacitance diode in Kubo's circuit. Cubert further suggested that switching between positive and negative supply voltages is a routine modification that does not alter the circuit's fundamental operation.
  • Expectation of Success: Petitioner argued that modifying Kubo based on Cubert's teachings was a predictable design choice. This modification directly addressed the only allegedly novel feature the ’318 patent claimed over the admitted conventional art, and Cubert demonstrated the feasibility and straightforwardness of such a design.

Ground 3: Claim 2 is obvious over Kubo in view of Suganuma.

• Prior Art Relied Upon: Kubo (Patent 4,751,475) and Suganuma (Patent 4,195,274).
• Core Argument for this Ground:
  • Prior Art Mapping: Claim 2 adds limitations requiring the temperature compensation circuit to include a diode and a fourth resistor, forming a voltage divider. Petitioner argued that while Kubo provided the foundational VCO and transistor-based compensation circuit, Suganuma taught these additional elements. Suganuma, which described its own circuit as "prior art," disclosed a temperature compensation circuit for a varactor diode that used a diode (D3) in series with a voltage divider (resistors R1 and R2) to achieve a temperature-dependent voltage shift.
  • Motivation to Combine: A POSITA would combine Suganuma's conventional temperature compensation technique with Kubo's circuit to achieve the same goal: compensating for frequency variations in a VCO. A POSITA would have recognized Suganuma’s diode and voltage divider as a known, effective module for level-shifting and temperature compensation that could be readily integrated into Kubo's design.
  • Expectation of Success: The combination of two conventional circuits for their intended and known purposes would have yielded a predictable result. Petitioner asserted that both references addressed the same problem, and integrating Suganuma's diode-based voltage divider into Kubo's circuit would predictably enhance temperature compensation by adjusting the voltage range applied to the variable-capacitance element.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under Fintiv, asserting that the inter partes review (IPR) was filed diligently before invalidity contentions were due in a parallel district court case, minimizing resource overlap. Petitioner further stipulated not to pursue in court any ground on which IPR is instituted.
• Petitioner also argued against denial under 35 U.S.C. §325(d), contending that the asserted combinations and secondary references (Webb, Cubert, Suganuma) were never considered during the original prosecution. While Kubo was cited in an Information Disclosure Statement, it was not the basis for a rejection, and the petition presented new arguments and combinations targeting the specific features identified by the examiner for allowance.

5. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1 and 2 of Patent 7,397,318 as unpatentable under 35 U.S.C. §103.