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`UNITED STATES PATENT AND TRADEMARK OFFICE
`______________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`______________________
`
`Intel Corporation
`Petitioner
`
`v.
`
`Qualcomm Incorporated
`Patent Owner
`______________________
`
`Case IPR2018-01154
`Patent 8,698,558
`______________________
`
`PATENT OWNER RESPONSE TO PETITION FOR INTER PARTES
`REVIEW PURSUANT TO 37 C.F.R. § 42.220
`
`
`
`
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`

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`TABLE OF CONTENTS
`INTRODUCTION ........................................................................................... 1 
`THE ’558 PATENT AND ITS PROSECUTION HISTORY ......................... 2 
`A.  Overview of the ’558 Patent .................................................................. 2 
`B. 
`Prosecution History of the ’558 Patent ................................................. 9 
`III.  CLAIM CONSTRUCTION .......................................................................... 10 
`IV.  LEVEL OF ORDINARY SKILL IN THE ART ........................................... 11 
`V.  OVERVIEW OF THE CITED REFERENCES ............................................ 11 
`A.  Overview of Kwak .............................................................................. 11 
`B.  Overview of Choi 2010 ....................................................................... 14 
`VI.  ALL GROUNDS OF THE PETITION SHOULD BE DISMISSED
`BECAUSE INDEPENDENT CLAIM 15 IS NOT ANTICIPATED BY
`KWAK ........................................................................................................... 17 
`Petitioner Improperly Combines Two Different Embodiments
`A. 
`from Kwak ........................................................................................... 17 
`Petitioner Disregards The Express Teachings Of Kwak Showing
`That The Feedforward Path Does Not Increase The Current
`Through The Inductor ......................................................................... 24 
`VII.  GROUND II OF THE PETITION SHOULD BE DISMISSED BECAUSE
`THE POSA WOULD NOT HAVE MODIFIED THE FEEDFORWARD
`PATH IN KWAK TO BE RELIANT ON THE BATTERY SUPPLY
`VOLTAGE .................................................................................................... 33 
`VIII.  GROUND III OF THE PETITION SHOULD BE DISMISSED BECAUSE
`IT IS BASED ON AN UNSUPPORTABLE CLAIM CONSTRUCTION OF
`“BASED ON THE FIRST SUPPLY VOLTAGE OR THE BOOSTED
`SUPPLY VOLTAGE” ................................................................................... 35 
`IX.  GROUND III OF THE PETITION SHOULD BE DISMISSED BECAUSE
`PETITIONER HAS FAILED TO PROVIDE A SUFFICIENT
`MOTIVATION TO COMBINE KWAK AND CHOI 2010 ......................... 41 
`CONCLUSION .............................................................................................. 43 
`
`B. 
`
`I. 
`II. 
`
`X. 
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`-i-
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`Pursuant to the Board’s Decision – Institution of Inter Partes Review (Paper
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`9) (“Institution Decision”), entered February 6, 2019 – Patent Owner Qualcomm,
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`Inc. (“Qualcomm” or “Patent Owner”) submits this Response in opposition to the
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`Petition for Inter Partes Review of U.S. Patent No. 8,698,558 (the “’558 Patent”)
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`filed by Intel Corporation (“Intel” or “Petitioner”).
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`I.
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`INTRODUCTION
`Petitioner raises three grounds against six claims, but all of those challenges
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`hinge on an anticipation ground directed to the only independent claim challenged,
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`claim 15. Petitioner’s anticipation analysis on claim 15 fails because the cited
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`prior art does not disclose a “switcher adding an offset to the input current to
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`generate a larger supply current via the inductor than without the offset,” as recited
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`in the claim. The other challenged claims depend from claim 15, including
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`Grounds II and III directed towards claims 16 and 19, respectively, and thus these
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`Grounds also fail.
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`Petitioner’s anticipation analysis relies on combining the teachings of two
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`different embodiments from the cited reference Kwak. These embodiments,
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`illustrated in Figures 5 and 6 of Kwak, however, include different circuit
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`components that fundamentally alter the function of the embodiments. Contrary to
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`established Federal Circuit precedent, Petitioner makes no attempt to explain how
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`a person of ordinary skill in the art (“POSA”) would at once envisage the claimed
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`1
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`arrangement or combination of the different embodiments. Accordingly, Petitioner
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`fails to meet its burden of proof.
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`Moreover, Petitioner mathematically erred in its analysis attempting to prove
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`that Kwak discloses a “switcher adding an offset to the input current to generate a
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`larger supply current via the inductor than without the offset,” as required by claim
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`15. When summing two alternating current (“AC”) signals, Petitioner failed to
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`account for the phase alignment of the AC signals. Petitioner’s conclusion rests on
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`the faulty premise that only the magnitude of the AC signals need be considered to
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`determine whether the supply current via the inductor is increased. This is wrong.
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`Compounding its error, Petitioner completely disregards the test results
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`presented in Figure 11 of Kwak, which show that the disclosed system does not
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`“generate a larger supply current via the inductor than without the offset,” as claim
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`15 requires. Figure 11 instead demonstrates that Kwak’s results are attributable to
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`aligning the phases of AC signals, not by increasing the magnitude of the supply
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`current via the inductor. For at least these reasons, the Board should confirm the
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`validity of claims 15-20 of the ’558 Patent.
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`II. THE ’558 PATENT AND ITS PROSECUTION HISTORY
`A. Overview of the ’558 Patent
`The ’558 Patent describes and claims inventions directed to managing the
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`power associated with transmitting radio frequency (“RF”) signals from a mobile
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`2
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`device. Ex. 1201 at 1:5-31. The ’558 Patent teaches improvements over known
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`power management schemes by employing a novel form of “envelope tracking.”
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`Id. at Title; 3:57-60. The ’558 Patent’s power management scheme achieves
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`substantial power savings in mobile device transmitters, thereby extending a
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`device’s battery life. Id. at 3:46-48.
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`In wireless communication systems, mobile devices communicate by
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`transmitting encoded data signals. Ex. 1201 at 1:11-17. Before transmitting
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`through a communications channel, such encoded data signals are first conditioned
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`to generate RF output signals. Id. Such conditioning typically includes an
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`amplification step performed by a power amplifier (a “PA”) that provides a high
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`transmit power. Id. at 1:21-26. A desirable characteristic of mobile device power
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`amplifiers is an ability to provide high transmit power with high power-added
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`efficiency (“PAE”) and good performance even when the device’s battery is low.
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`Id.
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`Before the priority date of the ’558 Patent, typical PAs in a mobile device
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`were supplied with a constant power supply voltage, regardless of the PA’s output
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`power. The ’558 Patent illustrates this in Figure 2A, below with annotation:
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`3
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`Figure 2A illustrates using a battery voltage (Vbat) to supply PA 210, which
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`provides an RFout signal as an amplified version of RFin. Ex. 1201 at 4:1-3.
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`RFout has a time-varying envelope illustrated by plot 250, which is juxtaposed
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`with voltage Vbat 260. Vbat remains higher than the largest amplitude of RFout’s
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`envelope in order to prevent clipping of RFout by PA 210. Id. at 4:2-7. A
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`drawback to this scheme is that the difference between the battery voltage and the
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`envelope of the RFout signal (shaded red) represents wasted power. Id. at 4:7-9.
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`As wasted power is undesirable, especially where power is limited by
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`battery life, the ’558 Patent employs “envelope tracking” in order to better manage
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`power consumption by using only an amount of power that is needed for a
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`particular signal. A PA employing envelope tracking is illustrated in Figure 2C,
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`with annotations, below:
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`4
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`By employing envelope tracking to produce a PA power supply Vpa,
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`represented in plot 280, the “supply voltage closely tracks the envelope [250] of
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`the RFout signal over time.” Ex. 1201 at 4:21-27. This maximizes PA efficiency
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`by minimizing the difference between Vpa and RFout over time, which results in
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`less wasted power. Id. at 4:27-32.
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`Implementing a PA supply with envelope tracking in a mobile device poses
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`unique challenges, because operating a mobile device with a low battery voltage is
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`often desirable (e.g., to reduce power consumption, extend battery life, etc.). Id. at
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`3:46-56. At times, a PA may need to operate with a higher voltage than a battery is
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`providing, in which case a boost converter may be employed at the expense of
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`increased cost and power consumption. Id.
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`To address these issues, the ’558 Patent discloses an efficient design for
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`envelope tracking that employs a “switcher” and an “envelope amplifier” together
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`with a boost converter, as illustrated in Figure 3, with annotations below:
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`5
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`Figure 3 illustrates an exemplary switcher 160a with envelope amplifier
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`170a operating cooperatively to create a supply current Ipa as the sum of Iind from
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`the switcher and Ienv from the envelope amplifier. Ex. 1201 at 4:34-38.
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`A switcher (e.g., 160a), “has high efficiency” and may deliver “a majority of
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`the supply current for [PA] 130” in current Iind, which contains DC and low
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`frequency components. Id. at 3:14-17; 6:19-20. An envelope amplifier (e.g.,
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`170a), on the other hand, operates as a linear stage and has high bandwidth. Id. at
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`6:20-22. In the combination the switcher reduces the output current of the
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`envelope amplifier thereby improving overall efficiency, while the envelope
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`amplifier provides the high frequency components in current Ienv. Id. at 3:21-25;
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`6:22-24. In this way, the overall efficiency increases by drawing the majority of
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`6
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`current from the high efficiency switcher, and only relying on the envelope
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`amplifier for the high frequency components.
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`In order to further increase the efficiency of the system, embodiments of a
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`switcher are designed to implement an offset to the input current (e.g., Isen in
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`Figure 3 above) “in order to generate a larger supply current via the inductor than
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`without the offset.” Ex. 1201 at 13:24-26; see also id. at 10:1-18. This offset is
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`intended to address an inefficiency arising in switchers where a reduced supply
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`voltage (e.g., a reduced Vbat) leads to a reduced supply current causing an inductor
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`to charge more slowly. Id. at 6:52-61. Within the context of the disclosed
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`apparatus, this has the practical effect of reducing Iind, resulting in the less
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`efficient envelope amplifier 170a providing more of the Ipa current. Id.
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`Thus, the ’558 Patent discloses an improved switcher, exemplified in Figure
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`5 (the relevant portion of which is copied below), incorporating a summer (e.g.,
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`summer 328) that is operative to sum the input of a sensed current (e.g., Isen) with
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`an offset current (e.g., Offset). Id. at 6:62-7:4. By providing a current as the sum
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`of the offset current and the sensed current, the switcher is “turned On for a longer
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`period and can provide a larger Iind current … [thus, the] offset provided to
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`summer 328 determines the amount by which the Iind current is increased by
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`switcher 160b [(below)] relative to the Iind current provided by switcher 160a in
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`Fig. 3 [(above)].” Id. at 7:10-18. This offset current ameliorates “the drop in
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`7
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`efficiency … by increasing the Iind current from the switcher.” Id. at 6:60-61;
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`7:19-21; 7:44-49; Abstract.
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`
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`The ’558 Patent also discloses embodiments improving the efficiency of the
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`envelope amplifier. Envelope amplifier 170a predominantly relies on Vbat for
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`power while drawing upon Vboost (which “boosts” or increases the battery voltage
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`to a higher voltage at the expense of cost and power consumption) on demand
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`when, e.g., the magnitude of the envelope signal exceeds a threshold. Id. at 3:19-
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`21; 3:52-67; 5:31-36; 6:1-4. In this way, the linear stage envelope amplifier only
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`draws on the boosted voltage when needed. Thus, in embodiments of the ’558
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`Patent, efficiency is increased by only relying on a boost converter with respect to
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`the envelope amplifier, and because the switcher provides power most of the time,
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`any efficiency drag from a boost converter is limited to “the time in which the
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`8
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`envelope amplifier 170 provides power.” Id. at 8:17-23. Efficiency, then, is
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`further increased because the envelope amplifier itself relies on the boost converter
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`dynamically, i.e., “only when needed for large amplitude envelope.” Id. at 6:28-33.
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`In light of these unique benefits provided by a switcher and an envelope
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`amplifier, the overall system efficiency can be optimized if the two suppliers of
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`energy are operated in tandem such that (1) the switcher, which is more efficient,
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`provides a majority of energy to the PA; and (2) the envelope amplifier, which is
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`less efficient but can more quickly adjust its output, provides only the fast-
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`changing (i.e., high frequency) portion of the energy to the PA. Embodiments of
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`the ’558 Patent increase efficiency by introducing an offset in the switcher in order
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`to increase the Iind current, thereby reducing the apparatus’ reliance on the less
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`efficient envelope amplifier (id. at 6:52-61); by configuring the envelope amplifier
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`to rely on the boost converter dynamically and only when necessary (id. at 6:28-
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`33); or by doing both.
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`B.
`Prosecution History of the ’558 Patent
`The ’558 Patent issued from U.S. Application No. 13/167,659, filed June 6,
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`2011. Ex. 1202 at 38. A first Office Action issued on November 23, 2012,
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`rejecting each original independent claim, including original claim 20, as
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`anticipated by Kim et al., entitled “High Efficiency and Wideband Envelope
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`Tracking Power Amplifier with Sweet Spot Tracking.” Ex. 1202 at 59-61; Ex.
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`9
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`1213 at Title. The Examiner provided a detailed examination of original claims
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`20-21, 24-26 in view of Kim, including claim 20, which issued as independent
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`claim 15. Ex. 1202 at 61-63. The Office found original claims 22 and 23
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`allowable over Kim if rewritten in independent form. Ex. 1202 at 79-82. To
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`overcome the rejections of claim 20, the Applicant cancelled claim 20 and rewrote
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`claim 22 in independent form by incorporating the subject matter of original
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`independent claim 20. Ex. 1202 at 84-85.
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`In a subsequent Final Office Action dated May 10, 2013, the Office
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`indicated that original claim 20 as amended recited allowable subject matter over
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`the prior art of record. Id. at 134. Thereafter, the Applicant and the Office
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`addressed unrelated claims before a Notice of Allowance was issued on Feb. 13,
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`2014; original claim 22 issued as claim 15, and original dependent claims 21, 23-
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`26 issued as claims 16-20. Id. at 185; 207.
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`III. CLAIM CONSTRUCTION
`Patent Owner does not believe that the terms “current sense amplifier” and
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`“envelope signal” need to be construed. To the extent the Board determines that
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`they should be construed, Patent Owner does not contest the Board’s previous
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`finding that “current sense amplifier” means “amplifier that produces a voltage
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`from a current,” and “envelope signal” means “signal indicative of the upper bound
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`of the output RF signal.” Paper 3 at 7-8.
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`10
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`Claim 19 recites “wherein the envelope amplifier operates based on the first
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`supply voltage or the boosted supply voltage.” The only reasonable interpretation
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`of this claim element, properly read within the context of the claim as a whole, is
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`that the envelope amplifier must be able to operate, selectively, based on either the
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`first supply voltage or the boosted supply voltage (referred to herein as a “selective
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`boost”). See Ex. 2002 at ¶¶48-56. Patent Owner presents its full claim
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`construction argument for “based on the first supply voltage or the boosted supply
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`voltage” below at Section VIII.
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`IV. LEVEL OF ORDINARY SKILL IN THE ART
`As the Board previously stated, the POSA for the ’558 Patent would have
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`had a Master’s degree in electrical engineering, computer engineering, or computer
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`science, and would also have had at least two years of relevant experience, or a
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`Bachelor’s degree in one of those fields and four years of relevant experience.
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`Paper 9 at 10. Relevant experience “refers to experience with mobile device
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`architecture as well as transmission and power circuitry for radio frequency
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`devices.” Id. Patent Owner does not dispute the Board’s statement of the level of
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`ordinary skill in the art. See also Ex. 2002 at ¶¶43-44.
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`V. OVERVIEW OF THE CITED REFERENCES
`A. Overview of Kwak
`The Kwak reference is an article entitled “A 2W CMOS Hybrid Switching
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`Amplitude Modulator for EDGE Polar Transmitters.” Ex. 1211 at Title. Kwak
`11
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`describes a hybrid switching amplifier with a master-slave architecture consisting
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`of a wideband linear amplifier as a voltage source and a switching amplifier as a
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`current-controlled current source. Ex. 1211 at 2666. Kwak teaches use of a pulse-
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`width modulation (PWM) controller for the switcher in order to mitigate design
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`difficulties. Id. at 2667. This is illustrated in Kwak’s Figure 3(a), below. Id. at
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`2668.
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`
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`Kwak teaches that power consumption of the linear amplifier may be
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`reduced by reducing the output ripple voltage. Id. at 2667. Kwak discloses that
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`one way to reduce the output ripple voltage is by introducing a “feedforward path.”
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`Id. at 2668-2669. According to Kwak, a linear amplifier provides compensation
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`current to prevent output voltage distortions (i.e., at (Vo)) caused by a delay of the
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`12
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`current loop (illustrated in Figure 3(a) above) at high frequencies. Id. at 2668. At
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`higher frequencies, more compensation current is required from the linear
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`amplifier, thus Kwak teaches adding an auxiliary feedforward circuit, allowing the
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`input signal to control the switching amplifier directly. Id. The switching
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`amplifier of Figure 3(a) with a modification to include a feed forward path is
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`illustrated below, in Kwak’s Figure 5. Id.
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`
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`Kwak explains that the feedforward path is introduced in order to “alleviate
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`the burden of the linear amplifier” due to distortions caused by the phase lag of the
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`switching regulator in a high frequency region of operation. Id. Without the
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`feedforward path, as a result of the phase delay, the linear amplifier is required to
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`13
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`provide additional support to maintain (Vo) at intended levels, as illustrated in
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`Kwak’s “[m]easured waveforms” depicted in Figure 11(a). Id. at 2668-69; 2673.
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`The feed forward path, being “faster than the feedback current path formed by
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`sensing the output current of the linear amplifier,” decreases the loop’s phase delay,
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`and thereby reduces the compensation current of the linear amplifier. Id. at 2669.
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`Figsures 11(a) and 11(b) (below) illustrate that the magnitude of the supply current
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`(id) remains the same as the magnitude of the linear amplifier current (ia) is reduced.
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`Id. at 2673. See also Ex. 2002 at ¶¶61-62.
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`
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`B. Overview of Choi 2010
`The Choi 2010 reference is an article entitled “Envelope Tracking Power
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`Amplifier Robust to Battery Depletion.” Ex. 1206 at Title. Choi 2010 describes a
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`“hybrid switching amplifier,” and Figure 2 illustrates how a PA supply modulator
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`topology affects the output power of the PA, as shown below:
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`14
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`Ex. 1206 at 1334.
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`Choi 2010’s objective is to develop an envelope tracking power amplifier
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`that prevents the degradation of output power that results from battery depletion.
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`Ex. 1106 at 1333. To accomplish this objective, Choi 2010 discloses a system that
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`boosts the supply voltage of a linear amplifier to 5V, regardless of the battery
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`voltage variation, by coupling a 5V boost converter to the supply of the linear
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`amplifier as illustrated in Figure 5 below. Id. at 1333. The system in Choi 2010
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`boosts the linear amplifier supply voltage, “while that of the buck converter is still
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`coupled to the battery in the HSA” so that “the supply modulator dynamically
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`regulates the PA with peak voltage of 4.5V.” Id.
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`15
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`Thus, Choi 2010 teaches that this system always boosts the battery voltage
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`to 5V, regardless of battery voltage fluctuation in order to provide a stable supply
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`voltage to the RF PA. Id. at 1334. Choi 2010 recognizes that this continuous
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`voltage boost degrades efficiency of the supply, but accepts this degradation as an
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`acceptable compromise to achieve a stable supply voltage for the RF PA. Id. at
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`1335 (“the efficiency degradation by the additional boost converter is not serious
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`because the load current provided by the linear amplifier is about 30% of the
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`overall load current”).
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`It is notable that four of the six authors of Choi 2010 were also authors of
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`the Kim paper that was distinguished during the prosecution of the ’558 Patent,
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`and Choi 2010 was also considered by the Examiner during prosecution. Ex. 1213
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`at 255; Ex. 1206 at 1332; Ex. 1201 at Cover.
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`16
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`VI. ALL GROUNDS OF THE PETITION SHOULD BE DISMISSED
`BECAUSE INDEPENDENT CLAIM 15 IS NOT ANTICIPATED
`BY KWAK
`The Petition includes only a single ground for independent claim 15, arguing
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`
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`that the claim is anticipated by Kwak. The remaining challenged claims each
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`depend from claim 15. Because Petitioner fails to establish anticipation of claim
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`15, each of the grounds fail, and validity of the challenged claims should be
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`confirmed.
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`A.
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`Petitioner Improperly Combines Two Different
`Embodiments from Kwak
`Independent claim 15 requires “a switcher operative to sense an input
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`current and generate the switching signal to charge and discharge the inductor to
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`provide the supply current, the switcher adding an offset to the input current to
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`generate a larger supply current via the inductor than without the offset.”
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`Petitioner relies on the hybrid switching amplifier shown in Figure 5 of Kwak as
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`allegedly disclosing the bulk of this claim element, but then relies on Kwak’s
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`Figure 6 for the claim requirement of “the switcher adding an offset to the input
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`current.” See Paper 3 at 42-49. To this end, Petitioner states that Figure 6 of
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`Kwak “is a detailed implementation of the type of circuit show in Figure 5.” Id. at
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`44. Kwak, however, describes Figures 5 and 6 as different embodiments, and
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`Petitioner has failed to provide any rationale for combining these different
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`embodiments to support a finding of anticipation under 35 U.S.C. § 102. Microsoft
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`17
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`Corp. v. Biscotti, Inc., 878 F.3d 1052, 1069 (Fed. Cir. 2017) (crediting the Board’s
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`explanation that “anticipation is not proven by multiple, distinct teachings that the
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`artisan might somehow combine to achieve the claimed invention.”) (citations
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`omitted).
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`In Biscotti, the Federal Circuit made clear that in order to anticipate a claim
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`“a prior art reference must disclose all elements of the claim within the four
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`corners of the document, and it must disclose those elements arranged as in the
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`claims.” “If [the reference] does not expressly spell out all the limitations arranged
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`or combined as in the claim,” it can only anticipate “if a person of skill in the art,
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`reading the reference, would at once envisage the claimed arrangement or
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`combination.” Id. (citations omitted). The petitioner in Biscotti relied on a
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`combination of two statements that referred to separate embodiments, but the
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`Board determined that while the two statements could disclose the “interface” at
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`issue, Petitioner had failed to put forth evidence showing that the statements
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`necessarily disclosed the claimed interface. Id. at 1065. The Federal Circuit
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`affirmed the Board’s holding and criticized “bare-bones allegations” in inter partes
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`review petitions that fail to provide information on how a POSA would understand
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`that separate embodiments anticipate a claim. Id. at 1074.
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`Petitioner similarly fails to provide any explanation of how separate
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`embodiments in the cited Kwak reference would allegedly be understood by a
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`18
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`POSA to anticipate claim 15. Petitioner relies on Figure 5 of Kwak throughout its
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`anticipation analysis of claim 15. A copy of Figure 5 (as highlighted by Petitioner)
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`is set forth below.
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`With reference to the highlighted version of Figure 5 (above), Petitioner
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`alleges that the driver AF (highlighted in orange) supplies an offset current that is
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`added to the sensed signal by the summing circuit ∑ (outlined in brown). See
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`Paper 3 at 43. In an attempt to support this conclusion, Petitioner turns to Figure 6
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`of Kwak, which, as noted above, Petitioner incorrectly refers to as “a detailed
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`implementation of the type of circuit shown in Figure 5.” A copy of Kwak’s
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`Figure 6 (as highlighted by Petitioner) is set forth below.
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`19
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`
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`Petitioner claims that “Figure 6 includes a ‘Summing Circuit + Integrator,’
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`which is the combination of the summing circuit of Figure 5 (∑, outlined in brown)
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`and the integrator AI(s) in Figure 5 (outlined in red),” and that “[t]his ‘Summing
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`Circuit + Integrator’ is shown to add an offset (i.e., the current from the
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`feedforward path, shown by the blue arrow) to an input current (shown by the dark
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`green arrow).” Id. at 45. But Figure 6 is not a “detailed implementation” of Figure
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`5, as Petitioner alleges. Rather, Figure 6 illustrates a hybrid switching amplifier
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`that employs a third-order ripple filter and current feedback not included in Figure
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`5, and replaces the summer and integrator of Figure 5 with a combined “summing
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`circuit and integrator” that has three inputs instead of two and operates in a
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`different manner. Ex. 2002 at ¶¶93-95.
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`20
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`
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`Petitioner places undue weight on Kwak’s statement that “Fig. 6 shows the
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`detailed circuit of the hybrid switching amplifier.” This statement does not refer to
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`Figure 5, but rather refers to “the hybrid switching amplifier” that is the subject of
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`Kwak’s paper. When read in the appropriate context, Kwak specifically
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`distinguishes the embodiment of Figure 6 from the embodiment of Figure 5, as
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`follows:
`
`Fig. 6 shows the detailed circuit of the hybrid switching
`amplifier. In CMOS design, although three voltage
`signals can be added and then integrated as shown in Fig.
`4 and 5, the simultaneous summation and integration of
`the signals at the node Vc, after the conversion of the
`three voltage signals into current ones, is advantageous,
`that is, the sensed output current of the linear amplifier,
`the feedforward current, and the high-frequency current
`through the ripple filter are added together and integrated
`at the node with the inverted polarity of the last one.
`
`Ex. 1211 at 2669 (emphasis added). This passage explains that Figure 6 involves
`
`the summation and integration of three current signals, including a high-frequency
`
`feedback current through the ripple filter. Figure 5, in contrast, illustrates the
`
`summation of only two signals – the outputs from the AF and AS blocks. Figure 5
`
`does not disclose a third input from a feedback path, nor does it disclose “the
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`switcher adding an offset to the input current,” as required by claim 15. Ex. 2002
`
`at ¶95.
`
`
`
`Petitioner’s expert confirmed that Figures 5 and 6 are not the same
`
`embodiment. When asked to describe the different figures, Dr. Apsel testified that
`
`Figure 6 is the circuit that Kwak is proposing in the publication. Dr. Apsel
`
`interprets the preceding figures, including Figures 4 and 5, as “demonstrations of
`
`concepts” that are independently presented “so that it’s easier for the reader to
`
`understand.” Ex. 2003 at 32:3-35. In fact, Dr. Apsel does not even consider
`
`Figures 4 and 5 to be standalone circuits. Id. at 34:16-23. Figure 6 therefore
`
`cannot be a “detailed implementation” of Figure 5 because Figure 6 includes
`
`numerous concepts entirely absent from Figure 5. Figures 5 and 6 of Kwak are
`
`separate embodiments.
`
`
`
`Presenting an anticipation ground based on two different embodiments,
`
`Petitioner was required to show that a POSA “would at once envisage the claimed
`
`arrangement or combination.” Biscotti, 878 F.3d at 1069. But Petitioner does not
`
`even allege that a POSA would have envisaged the combination, let alone explain
`
`why or how. Like the petitioner in Biscotti, here Petitioner’s bare-bones
`
`allegations fail to provide any information on how a POSA would understand that
`
`Kwak’s separate embodiments of Figsures 5 and 6 anticipate claim 15. See id. at
`
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`22
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`

`

`1074. Thus, Petitioner has failed to meet their burden of proof that a POSA would
`
`at once envisage the claimed invention.
`
`
`
`Petitioner proposes only that independent claim 15 is anticipated by Kwak
`
`under 35 U.S.C. § 102. Therefore, whether claim 15 is somehow obvious over the
`
`combination of Figures 5 and 6 is not relevant to the grounds set forth in the
`
`Petition. Nonetheless, even if an obviousness ground were properly before the
`
`Board for claim 15, Petitioner completely fails to address Kwak’s distinction
`
`between the embodiments of Figures 5 and 6 and thus fails to provide any rationale
`
`as to why the POSA would combine these different embodiments. A patent may
`
`be found obvious in view of a single reference, only “if it would have been obvious
`
`to modify that reference to arrive at the patented invention.” Arendi S.A.R.L. v.
`
`Apple Inc., 832 F.3d 1355, 1361 (Fed. Cir. 2016). In Arendi, the Federal Circuit
`
`explained that it is Petitioner’s burden “to provide more than a mere scintilla of
`
`evidence” that common sense would have “evidently and indisputably” supplied
`
`the utility of the alleged modification. Id. at 1365. Here, Petitioner fails to allege
`
`anything, common sense or otherwise, that would motivate a POSA to modify
`
`Kwak’s Figure 5 embodiment with Kwak’s Figure 6 embodiment (or vice versa).
`
`Therefore, even if the obviousness of claim 15 in view of Kwak were properly
`
`before this Board (which it is not), a finding of obviousness cannot be supported by
`
`the Petition.
`
`
`
`23
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`

`

`
`
`For at least these additional reasons, Petitioner has failed to establish that
`
`Kwak anticipates independent claim 15. Because all grounds set forth in the
`
`Petition rely on the anticipation allegations against claim 15, the Board should
`
`confirm the validity of all challenged claims.
`
`B.
`
`Petitioner Disregards The Express Teachings Of
`Kwak Showing That The Feedforward Path Does Not
`Increase The Current Through The Inductor
`As explained above, Petitioner fails to explain how a POSA would at once
`
`envisage the claimed arrangement or combination of Figures 5 and 6 of Kwak. But
`
`even if the Board were to find otherwise, Kwak presents oscilloscope testing
`
`results conclusively showing that its feedforward path does not cause any change
`
`in the magnitude of the supply current (id) through the inductor. Figure 11(a)
`
`(annotated below) illustrates measured waveforms of (id) and (Vo) “without the
`
`feedforward path,” and Figure 11(b) (annotated below) illustrates the same
`
`waveforms “with the feedforward path.” Ex. 1211 at 2673.
`
`
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`24
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`

`

`
`
`
`
`As explained in more detail below, a comparison between Figures 11(a) and
`
`11(b) reveals that the feedforward path causes a phase shift in supply current (id)
`
`(demonstrated by the vertical blue line shifting left), but no increased magnitude
`
`(demonstrated by the horizontal blue line). Thus, Kwak fails to disclose the claim
`
`15 limitation “the switcher adding an offset to the input current to generate a
`
`larger supply current via the inductor than without the offset.”
`
`Kwak sets out to solve a problem with conventional hybrid switching
`
`amplifiers. In an ideal hybrid switching amplifier, the output current of the
`
`switcher supplies most or all of the overall circuit’s output current, and the linear
`
`amplifier supplies little to no current. Ex. 1211 at 2666; 2669. “In reality,
`
`however, as shown in Fig. 2(b), the output current of the switching amplifier (id) is
`
`
`
`25
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`

`

`slower and less than the output current (io) because of the finite loop gain β. Thus,
`
`the linear amplifier must provide some amount of signal current in addition to the
`
`ripple current [output current of the switching amplifier (id)] to comp