IPR2018-01154
`U.S. Patent No. 8,698,558
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`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
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`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`Intel Corporation
`Petitioner
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`v.
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`Qualcomm Incorporated
`Patent Owner
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`IPR2018-01154
`U.S. Patent No. 8,698,558
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`PETITIONER’S REPLY
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`IPR2018-01154
`U.S. Patent No. 8,698,558
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`I. 
`II. 
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`2. 
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`TABLE OF CONTENTS
`Introduction ...................................................................................................... 1 
`Claim Construction .......................................................................................... 2 
`A. 
`PO’s Proposed Construction Is Wrong ................................................. 2 
`1. 
`PO’s Proposed Construction Contradicts The Plain Claim
`Language ..................................................................................... 3 
`PO’s Proposed Construction Would Exclude Disclosed
`Embodiments .............................................................................. 6 
`PO’s Remaining Arguments Have No Merit .............................. 8 
`3. 
`III.  Grounds ............................................................................................................ 9 
`A. 
`Claim 15 is anticipated by Kwak .......................................................... 9 
`1. 
`Kwak’s feedforward path increases the inductor current ........... 9 
`(a)  Diagrams in Dr. Kelley’s Declaration Do Not Depict Kwak ............. 11 
`(b)  PO Misinterprets Kwak’s Figure ........................................................ 12 
`(c)  PO’s Argument That Kwak’s Feedforward Path Affects Only The
`Phase Of The Inductor Current Is Wrong .................................................... 18 
`B. 
`Petitioner Has Not Improperly Combined Two Different Kwak
`Embodiments ....................................................................................... 20 
`1. 
`Figure 5 Alone Anticipates Claim 15 ....................................... 20 
`2. 
`Figure 6 Shows A Detailed Implementation of a Figure 5 ....... 23 
`Claim 16 Is Unpatentable .................................................................... 24 
`PO Is Wrong That Petition Fails To Demonstrate a Motivation
`to Combine Kwak with Choi 2010 ...................................................... 25 
`1. 
`PO Misrepresents Petitioner’s Argument ................................. 25 
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`C. 
`D. 
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`i
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`IPR2018-01154
`U.S. Patent No. 8,698,558
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`I.
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`INTRODUCTION
`Patent Owner’s Response (“POR”) confirms that the challenged claims of
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`the ʼ558 patent are invalid. Indeed, the POR’s challenge of Petitioner’s mapping
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`of the limitations to the cited references is based on arguments that Patent Owner’s
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`(“PO”) own expert, Dr. Arthur Kelley, contradicted during cross-examination and
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`on an improper claim construction.
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`First, PO’s arguments that Kwak’s feedforward path does not increase the
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`inductor current is based on diagrams that, as Dr. Kelley admitted in deposition, do
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`not depict Kwak, on a misinterpretation of Kwak’s Figure 11, and on an erroneous
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`assumption that Kwak’s feedforward path affects only the inductor current phase.
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`Second, PO seeks to re-write the claim elements in the guise of claim
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`construction. But its proffered construction contradicts the surrounding claim
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`language, would exclude disclosed embodiments, and is inconsistent with the
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`specification––as Dr. Kelley admitted in deposition. See Ex. 1229 [Kelley
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`Transcript], 35:15-36:1; 37:5-16; 37:20-38:11; 133:4-135:9; see also EPOS Techs.
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`Ltd. v. Pegasus Techs. Ltd., 766 F.3d 1338, 1347 (Fed. Cir. 2014) (rejecting
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`construction “because it reads out preferred embodiments”); see also Dow Chem.
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`Co. v. Sumitomo Chem. Co., 257 F.3d 1364, 1378 (“a claim construction that
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`excludes a preferred embodiment is ‘rarely, if ever, correct.’”).
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`Third, PO’s critique that modifying Kwak to add Choi 2010’s boost
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`converter “would not be possible without undue experimentation” (POR, 42) is
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`wrong. PO does not dispute the benefits identified by Petitioner with regard to the
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`motivation to combine Kwak and Choi 2010 (Petition, 63-67). See, POR, 41-43.
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`Instead, PO argues that each of Kwak and Choi 2010 includes controllers that the
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`other disparages. This is irrelevant, however. As Dr. Kelley admitted, adding a
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`boost converter in a modulator powered by a battery supply was within the skill of
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`a person of ordinary skill in the art (“POSA”). Ex. 1229, 152:21-153:4; 283:16-
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`284:1.
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`For these reasons, as set forth more fully below, PO’s arguments should be
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`rejected and the challenged claims found unpatentable.
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`II. CLAIM CONSTRUCTION
`A.
`PO’s Proposed Construction Is Wrong
`PO contends that the term “the envelope amplifier operates based on the first
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`supply voltage or the boosted supply voltage” should be construed such that “the
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`envelope amplifier must be able to operate, selectively, based on either the first
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`supply voltage or the boosted supply voltage (referred to herein as a ‘selective
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`boost’).” (POR, 11, 35.) According to Patent Owner, an amplifier that received
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`only the first voltage or only the boosted voltage would not meet this limitation.
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`This proposed construction is far from the broadest reasonable construction of
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`“or,” is contrary to the plain meaning, and excludes disclosed embodiments. It
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`should be rejected.
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`1. PO’s Proposed Construction Contradicts The Plain Claim
`Language
`Claim 19 recites an “envelope amplifier” that “operates based on the first
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`supply voltage or the boosted supply voltage.” Ex. 1201, 14:25-27. As Dr. Kelley
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`conceded, the term “or” is a conjunction that identifies two alternatives: this “or”
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`that. (Ex. 1229, 130:10-18 (“Q. I’m asking at the Schoolhouse Rock level, or is a
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`conjunction that joins two alternatives, correct? A. Well, if we’re going to import
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`Schoolhouse Rock into the deposition, in that context, yes, it is.”).) Under its plain
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`meaning, the requirement for an amplifier that operates based on “the first supply
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`voltage or the boosted supply voltage” is met by an amplifier that operates based
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`on either alternative alone. (Id. at 130:19-131:2 (“Q.…If I said I would like coffee
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`or tea, you could give me tea and that would meet my requirement, right? A. In
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`that hypothetical abstract outside the bounds of the ’558, sure.”). PO has identified
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`no sound basis to deviate from that broad plain meaning. Ex. 1228, ¶5.
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`To the contrary, PO concedes that the common meaning of “or” in patent
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`claims is to recite alternatives. See, POR, 39 (“The use of ‘or’ is sometimes an
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`acceptable mechanism for claiming alternatives such that only one of the
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`limitations need be found in the prior art to support anticipation.”) And that is
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`exactly how Hon. Dana M. Sabraw construed “or” in the related district court
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`litigation on the ’558 patent. (Ex. 1227 [Claim Constr. Order] at 5-6 (holding the
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`limitation “a source receiving the boosted supply voltage or the first supply
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`voltage” in claim 6 does not require “selective boost”).) Indeed, Dr. Kelley
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`admitted PO’s proffered construction contradicts Judge Sabraw:
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`Q. And just to be clear, you’re giving an opinion that is contrary to
`Judge Sabraw’s claim construction, right?
`I understand what the Judge did. And I’ve reached a different
`conclusion.
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`A.
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`Ex. 1229, 147:10-151. But if “or” covers either alternative alone under the Phillips
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`standard that Judge Sabraw used, it is certainly at least that broad under the
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`broadest reasonable construction rule applicable here. Facebook, Inc. v.
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`Pragmatus AV, LLC, 582 Fed. Appx. 864, 869 (“The broadest reasonable
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`interpretation of a claim term may be the same as or broader than the construction
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`of a term under the Phillips standard. But it cannot be narrower.”) An envelope
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`amplifier that operates based on either one of the recited alternatives – e.g., the
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`“boosted supply voltage” alone – would thus meet the claim.
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`Moreover, other claims demonstrate that PO knew how to recite “selective
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`boost” when it wanted – using language different from claim 19. Independent
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` Objections omitted in transcript quotations.
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`claim 6 and dependent claim 7 provide one such example. Much like claim 19,
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`claim 6 recites “a source receiving the boosted supply voltage or the first supply
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`voltage….” Claims 6 is therefore met using only one of the boosted or first supply
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`voltage. Indeed, as noted above, Judge Sabraw found that this claim does not
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`require “selective boost.” (Ex. 1227, 5-6.) By contrast, dependent claim 7 adds
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`the limitation “wherein the supply generator is operative to generate the second
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`supply voltage based on the envelope signal and either the boosted supply voltage
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`or the first supply voltage.” If claim 6 already required “selective boost,” then
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`claim 7 would add nothing. But consistent with claim differentiation doctrine,
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`claim 7’s additional language “and either” has meaning. For that reason, claim 7
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`could not be read to require only one of the boosted or first supply voltage. It is
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`therefore that additional language appearing in claim 7 (which does not appear in
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`either claim 6 or 19) that adds a requirement for the amplifier to be able to select
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`between “either” the boosted voltage “or” the first supply voltage. Because claim
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`19 (like claim 6) lacks this “and either” language, it has no such requirement.
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`Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005) (“a dependent claim
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`that adds a particular limitation gives rise to a presumption that the limitation…is
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`not present in the independent claim.”)
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`2. PO’s Proposed Construction Would Exclude Disclosed
`Embodiments
`PO’s construction should also be rejected, because it improperly excludes
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`disclosed embodiments. EPOS, 766 F.3d at 1347; Dow, 257 F.3d, at 1378.
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`Specifically, the ’558 specification (starting at 8:24) teaches “another design
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`of supporting operation with a lower battery voltage[.]” (Ex. 1201, 8:24-25.) In
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`this embodiment, “the entire envelope tracker is operated based on the Vboost
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`voltage from boost converter 180” alone (i.e., solely based on “boosted supply
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`voltage”), without ever operating based on battery voltage (i.e., never based on
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`“first supply voltage”). (Id., 8:25-26.) As Dr. Kelley admitted in deposition when
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`asked about claim 13, which recites language similar to claim 19, PO’s
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`construction would exclude this embodiment:
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`Q.
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`If you’re right that the selective boost and the or means I have
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`to be able to use either boost or first, then under that
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`circumstance, claim [6] and 13 would not cover the
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`embodiment at column 8, line 24 that uses Vboost alone. Is
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`that fair?
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`A.
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`I think that’s fair.
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`(Ex. 1229, 134:12-18.) Because PO’s proposed construction would exclude
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`this disclosed embodiment, it should be rejected. EPOS, 766 F.3d, 1347;
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`Dow, 257 F.3d, 1378.
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`PO’s argument is also an improper attempt to limit claim 19 solely to one
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`disclosed embodiment (to the exclusion of others). For example, PO contends that
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`column 1, lines 42-50 discloses a form of “selective boost.” Whether the
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`specification here means what PO says is debatable. But what is beyond dispute is
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`that column 1 discloses merely “one design” as an “example” that in no way limits
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`the claims:
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`In one design, the envelope amplifier may further receive the first
`supply voltage and may generate the second supply voltage based on
`either the first supply voltage or the boosted supply voltage. For
`example, the envelope amplifier may generate the second supply
`voltage (i) based on the boosted supply voltage if the envelope signal
`exceeds a first threshold and/or if the first supply voltage is below a
`second threshold or (ii) based on the first supply voltage otherwise.
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`(Ex. 1201, 1:42-50. (emphasis added).) PO’s citation to 8:55-62 is similarly
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`misplaced. (Id., 8:55-62 (“In one design….For example,…”).) As the Federal
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`Circuit has admonished, confining claims to one disclosed embodiment is the
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`“cardinal sin” of claim construction. Phillips, 415 F.3d, 1320 (“although the
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`specification often describes very specific embodiments of the invention, we have
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`repeatedly warned against confining the claims to those embodiments.”); see also
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`Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875 (Fed. Cir. 2004)
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`(“a particular embodiment appearing in the written description may not be read
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`U.S. Patent No. 8,698,558
`into a claim”); E-Pass Techs., Inc. v. 3Com Corp., 343 F.3d 1364, 1369 (Fed. Cir.
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`2003) (cautioning against “importing limitations”). PO’s blatant attempt to do so
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`here should be rejected.
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`3. PO’s Remaining Arguments Have No Merit
`Finally, PO suggests that Dr. Alyssa Apsel somehow “agreed that it would
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`not make sense to interpret the boosted supply voltage as purely optional in the
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`context of the claims” (POR, 40), because “when asked about a similar ‘based on’
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`limitation in claim 6,” she supposedly “admitted that it makes sense to interpret
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`‘based on’ as requiring a boosted supply voltage to be an available supply
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`voltage.” Id.
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`The language from claim 6 that Dr. Apsel addressed in this testimony recites
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`“generat[ing] a second supply voltage for the power amplifier based on the
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`envelope signal and the boosted supply voltage.” (Ex. 2003 [Apsel Transcript],
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`41:21-23; Ex. 1201, 11:49-51.) This is not similar to claim 19, which plainly
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`recites “or” not “and.”2 (Ex. 1201, claim 19.) By reciting “or,” claim 19 is clear
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` 2
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` It is also different from the relevant part of claim 6 that Judge Sabraw
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`interpreted, which appears at 11:58-59 . (Ex. 1201, 11:41-63.)
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`that either one of the “boosted supply voltage” or “the first supply voltage” is
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`alone sufficient to meet the claim’s requirement. Ex. 1228, ¶12.
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`PO’s proposed construction should thus be rejected.
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`III. GROUNDS
`A. Claim 15 is anticipated by Kwak
`As the petition showed, claim 15 is anticipated by Kwak. Petition, 38-51.
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`PO raises only two arguments for why claim 15 is allegedly not anticipated.
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`First, PO argues that Kwak’s feedforward path does not increase the inductor
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`current. POR, 24-33. Second, PO argues that Petitioner improperly combines two
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`different embodiments of Kwak. POR, 17-24. As explained below, both
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`arguments are incorrect.
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`1. Kwak’s feedforward path increases the inductor current
`Kwak discloses switching amplifiers in Figures 3(a) and 5. Kwak’s Figure 5
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`modifies Figure 3(a) by adding a feedforward path. Ex. 1211, 2668-2669. In both
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`Figures 3(a) and 5, the output current (io) equals the sum of the linear amplifier
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`current (ia) and the inductor current (id), i.e., io= ia+id. Ex. 1211, 2668. PO
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`concedes that use of the feedforward path does not change the output current, io.
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`POR, 27. PO also concedes that it was known in the art that switchers are more
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`efficient than linear amplifiers, and that it was therefore known to be desirable to
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`maximize the inductor current and reduce the linear amplifier current. Ex. 1229,
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`185:19-186:10; Ex. 1228, ¶16.
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`Kwak explains that, in theory “the linear amplifier only delivers the
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`switching ripple current of the switching amplifier because the switching amplifier
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`supplies most of the output current through the relation of io=ia+id =(1+β)‧ia.” Ex.
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`1211, 2666. But as Kwak recognizes, “[i]n reality, however, [] the output current
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`of the switching amplifier (id) is slower and less than the output current (io) because
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`of the finite loop gain β. Thus, the linear amplifier must provide some amount of
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`signal current in addition to the ripple current to compensate for the distortion that
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`results from the phase lag of the switching stage in the high-frequency region.” Id.
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`Kwak thus states that the linear amplifier does not merely provide ripple
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`cancelation current–it also provides “some amount of the signal current.” Ex.
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`1228, ¶17.
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`The purpose of Kwak’s feedforward path (Figure 5) is reducing the signal
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`current from the linear amplifier. See, Ex. 1211, 2668 (“Hence, an auxiliary circuit
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`[feedforward path] is necessary to alleviate the burden of the linear amplifier.”)
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`Use of the feedforward path reduces the burden on the linear amplifier (i.e.,
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`decreases ia) . According to Kwak’s equation (io=ia+id), the only way that total
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`current (io) can remain constant when linear amplifier current (ia) is decreased is if
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`the inductor current (id) increases. Indeed, that is the point of Kwak’s feedforward
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`path––to reduce the burden on the linear amplifier (i.e., reduce ia) by increasing the
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`inductor current (i.e., increase id). Ex. 1228, ¶18.
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`PO cannot escape from this clear interpretation of Kwak. Consequently, PO
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`relies on misleading diagrams in its expert declarations, flawed visual inspection of
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`Kwak’s Figure 11, and mischaracterization of Kwak’s equation 4. Ex. 1228, ¶19.
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`(a) Diagrams in Dr. Kelley’s Declaration Do Not Depict
`Kwak
`In his declaration, Dr. Kelley presents several graphs to support his
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`argument that decreasing the linear amplifier current (ia) does not increase the
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`inductor current (id). Ex. 2002, ¶¶77-80; POR, 28-29. At his deposition, however,
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`Dr. Kelley conceded that those graphs do not represent Kwak and instead merely
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`represent mathematical addition of sine waves. Ex. 1228, ¶20.
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`Q. So the assumption that the amplitude, the peak to peak
`amplitude of Id equals Io, Kwak at Page 2673 bottom of the left
`column says that it is not correct, right?
`A
`Again, my waveforms are an illustration of how to do
`math with sine waves. They are not meant to directly reproduce
`Figure 11 of Kwak.”
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`Ex. 1229, 232:19-233:5. Ex. 1228, ¶20.
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`Because Dr. Kelley admits that his graphs do not represent Kwak, this
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`argument from PO is entitled to no weight.
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`11
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`(b) PO Misinterprets Kwak’s Figure
`PO argues that “a comparison between Figures 11(a) and 11(b) reveals that
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`the feedforward path causes a phase shift in supply current (id) [], but no increased
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`magnitude [].” POR, 25. Specifically, PO argues that even though the addition of
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`the feedforward path in Figure 11(b) results in a decrease in the linear amplifier
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`current, Figure 11(b) does not show any increase in the inductor current. See, id.,
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`32. PO is wrong. In particular, this argument is based solely on a visual inspection
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`of Figures 11(a) and (b). But those figures are not properly scaled to show changes
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`in the inductor current, as Dr. Kelley conceded. Ex. 1229, 204:1-205:3. Ex. 1228,
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`¶22.
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`First, Kwak’s Figure 11 uses different scales to represent the linear
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`amplifier current, ia, and the inductor current, id. That is, Figure 11 uses a step-size
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`of 200mA for the linear amplifier current, ia, but uses a step-size of 500mA for the
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`switcher current, id. These scales are highlighted in Kwak’s Figure 11. Ex. 1228,
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`¶23.
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`IPR2018-01154
`U.S. Patent No. 8,698,558
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`Ex. 2011, Fig. 11
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`Therefore, in Figure 11, a change of one division for the inductor current, id
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`(i.e., a change from one dashed horizontal line to the next) represents a change that
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`is 250% greater than a change of one division for the linear amplifier current, ia.
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`Because of these different step sizes, it is much easier to see small changes in the
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`linear amplifier current, ia, than it is to see the same small change in the inductor
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`current, id. Dr. Kelley admitted this. “Certainly at this particular resolution you
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`wouldn’t see a 1 percent change.” Ex. 1229, 205:1-3. See also, id., 204:1-205:3.
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`Ex. 1228, ¶24.
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`Second, any decrease in the linear amplifier current, ia, caused by Kwak’s
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`feedforward path is balanced by an identical increase in the inductor current, id.
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`This is so because, as PO concedes, use of the feedforward path does not change
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`the output current, io. POR, 27. Therefore, because io=ia+id, and because io
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`remains unchanged, if ia decreases, id must increase by the identical amount.
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`Because Figure 11 uses different scales, the decrease in linear amplifier current, ia,
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`is more visible than the identical increase in inductor current, id. But Kwak’s
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`equation confirms that inductor current id must increase. Ex. 1228, ¶25.
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`Third, a POSA would have understood that Kwak’s inductor current, id, was
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`much larger than the linear amplifier current, ia, and indeed this is what Figure 11
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`shows. This is so because, as PO concedes, switchers are more efficient than linear
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`amplifiers and it was well-known to maximize contribution of the switcher. For
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`example, the inductor may provide 80% or more of the total current, where the
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`linear amplifier may provide only 20% or less. Therefore, any decrease in the
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`linear amplifier current, ia, caused by Kwak’s feedforward path will be much easier
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`visible in Figure 11 than the corresponding increase in the switcher current, id. For
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`example, sticking with the 80-20% example, suppose the switcher current, id, is
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`80mA and the linear amplifier current, ia, is 20mA without the feedforward path.
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`Suppose further that activating Kwak’s feedforward path decreases the linear
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`amplifier by 2mA. That would be a 10% reduction in linear amplifier current, ia.
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`However, the corresponding 2mA increase in switcher current, id, would be a 2.5%
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`increase, which would be harder to perceive than the 10% decrease in ia. Ex. 1228,
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`¶26.
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`Notwithstanding these differences in the scales, close examination of Figure
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`11 leads to the opposite of PO’s conclusion. PO provides an annotated Figure 11
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`(reproduced below) and argues that “[a]s can be seen by comparing the vertical red
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`lines to the vertical blue lines, the phase lag of (id) is noticeably reduced in Figure
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`11(b) with the feedforward path compared to the phase lag in Figure 11(a) without
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`the feedforward path. Meanwhile, the magnitude of supply current (id) remains the
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`same in both Figures 11(a) and 11(b), as denoted by the horizontal blue lines.”
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`POR, 31 (internal citations omitted.) Ex. 1228, ¶27.
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`POR, 32 (Fig. 11 annotated by PO)
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`PO misrepresents Kwak. PO argues that because the maximum value of
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`inductor current id (indicated by the blue horizontal line) is the same in both
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`figures, the magnitude of the inductor current remains the same. However, as
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`explained below, while the magnitude of the highest peaks in the inductor current,
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`id, are the same in Figures 11(a) and (b), the valleys, or lowest peaks, of id are not.
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`Because the valley of id is lower in Figure 11(b) than it is in Figure 11(a), and
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`because the highest peaks are the same, the peak-to-peak magnitude of the inductor
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`current, id, is larger in Figure 11(b) than in Figure 11(a). Ex. 1228, ¶28.
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`As Kwak explains, the magnitude of the AC component of the current is
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`measured by its peak-to-peak value. Ex. 2011, 2673 (“Without the feedforward
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`path, as shown in Fig. 11(a), the output current of the linear amplifier is
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`approximately 120mAPP. In contrast, as shown in Fig. 11(b), this value is reduced
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`to about half when the feedforward path is used.”) The “PP” subscript in Kwak
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`corresponds to “peak-to-peak.” PO admits “that the magnitude and phase of output
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`(Vo) remain constant with and without the feedforward path.” Accordingly, the
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`minimum value of signal Vo is at the same point in both figures, as Dr. Kelley
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`testified: “Q. But the minimum values of Vo are the same in 11(a) and 11(b), right?
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`A. I understand that they’re the same.” Ex. 1229, 207:9-13. Ex. 1228, ¶29.
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`This is illustrated in the excerpted detail from PO’s illustration below, in
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`which the orange lines identify the valleys of the output voltage, Vo, and the green
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`lines identify the valleys of the inductor current, id. Ex. 1228, ¶30.
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`POR, 32 (Fig. 11, excerpted and annotated)
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`According to PO and Dr. Kelley, the orange horizontal lines are at the same
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`points in Figures 11(a) and 11(b) (The figures are not perfectly aligned in the page.
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`Fig. 11(b) is slightly higher). POR, 31; Ex. 2002, ¶87. In the illustration above,
`
`the distance between the orange and green lines is smaller in Figure 11(b) than in
`
`Figure 11(a). That is, the distance between the valleys of the output voltage, Vo,
`
`and the inductor current, id, is bigger in Figure 11(a) than Figure 11(b). Indeed, Dr.
`
`Kelley admitted that the inductor current id valley (green) is closer to the Vo valley
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`(orange) in Figure 11(b) than it is in 11(a), thereby conceding that the peak-to-peak
`
`distance in Figure 11(b) has increased:
`
`Q. …Is it true, yes or no, that the vertical distance between
`the lowest point of Vo and the lowest point of Id in (a) is greater than
`the vertical distance between the lowest point of Vo and the lowest
`point of Id in (b)?
`A. Yes. That’s what produces the current Ia.
`
`Ex. 1229, 217:12-19.3 This confirms that the peak-to-peak value of current id has
`
`increased in Fig. 11(b), because the valley, or lowest peak, of id (green line) has
`
`decreased, while the highest peak remained the same. Ex. 1228, ¶31.
`
`Accordingly, even PO’s illustration confirms that Kwak’s feedforward path
`
`increases the inductor current. Ex. 1228, ¶32.
`
`(c)
`
`PO’s Argument That Kwak’s Feedforward Path
`Affects Only The Phase Of The Inductor Current Is
`Wrong
`PO argues that Kwak’s feedforward path changes the phase of the inductor
`
`current, but not its magnitude. POR, 29. As explained below, PO is mistaken.
`
`
`
` 3
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` In redirect, when asked about the peak-to-peak magnitude of inductor current id,
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`Dr. Kelley contradicted himself by arguing there is no change in the peak-to-peak
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`magnitude.
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`U.S. Patent No. 8,698,558
`In Kwak’s Figures 3(a) and 5, the output current, io, equals the sum of the
`
`linear amplifier current, ia, and the inductor current, id. Ex. 1211, 2668-2669.
`
`Kwak’s equation 4 shows this and further shows that the inductor current, id, has
`
`two components: (1) the sensed current from current sensor AS, “ASꞏiaꞏC,” and (2)
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`the offset current, “AFꞏvinꞏC,” from the feedforward path AF, where “C=AIꞏAM
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`ꞏ(1/(ZL+sL)).” Id., 2669. Therefore, the output current depends on the linear
`
`amplifier current (ia), the sensed current (ASꞏia), and the offset current (AFꞏvin). Ex.
`
`1228, ¶34.
`
`As PO concedes, use of the feedforward path does not change the output
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`current, io. POR, 27. As Kwak states explicitly, use of the feedforward path
`
`decreases the linear amplifier current, ia. Ex. 1211, 2668-69. Decreasing the linear
`
`amplifier current, ia, decreases the first component of the inductor current: ASꞏiaꞏC.
`
`Therefore, maintaining the same output current requires increasing the second
`
`component of the inductor current: AFꞏvinꞏC. The increase in this component
`
`offsets the decrease in the linear amplifier current, ia. Said more simply, because
`
`io=ia+id, and because io remains constant, any decrease in ia must be offset by an
`
`increase in id. Ex. 1228, ¶35.
`
`In his analysis, Dr. Kelley, assumed that the magnitude of the inductor
`
`current, id, remains constant. Ex. 2002, ¶77. But by doing so he assumed the
`
`conclusion he was trying to prove. Ex. 1228, ¶36.
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`IPR2018-01154
`U.S. Patent No. 8,698,558
`In any case, Dr. Kelley repeatedly admitted that neither Kwak nor a POSA
`
`would require inductor current to remain constant. See Ex. 1229, 252:3-4 (“A. The
`
`switcher is trying to provide most of the current Io by way of Id.”); see also id.,
`
`184:11-185:4; 185:19-186:10; 195:9-15; 196:7-18. For example, Dr. Kelley
`
`testified that a POSA would try to increase the inductor current to the extent
`
`possible:
`
`Q. And a person of ordinary skill would understand that it
`would be desirable from an efficiency standpoint to have the switcher
`produce as much energy as possible, right?
`A.
`I think it would be better phrased the switcher provides
`as much current as possible.
`
`Ex. 1229, 245:15-21. Ex. 1228, ¶¶37-40.
`
`B.
`
`Petitioner Has Not Improperly Combined Two Different Kwak
`Embodiments
`PO alleges that “Petitioner relies on the hybrid switching amplifier shown in
`
`Figure 5 of Kwak as allegedly disclosing the bulk of this claim element, but then
`
`relies on Kwak’s Figure 6 for the claim requirement of ‘the switcher adding an
`
`offset to the input current.’” POR, 17.
`
`1. Figure 5 Alone Anticipates Claim 15
`In its attempt to create (non-existent) distance between Kwak and claim 15,
`
`PO misrepresents Petitioner’s arguments. Specifically, PO is wrong that Petitioner
`
`relies on Figure 6 for “the switcher adding an offset to the input current” limitation.
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`U.S. Patent No. 8,698,558
`Petitioner presented arguments that independently show how Kwak’s Figure 5 and
`
`the relevant disclosure teach this limitation. Ex. 1228, ¶42.
`
`For example, the Petition states “[a]s shown in Figure 5 [] Kwak discloses
`
`the internal structure of the supply generator, including the miscellaneous claim
`
`elements that the Examiner found were missing from the prior art during
`
`prosecution (operational amplifier, driver, and PMOS and NMOS transistors).”
`
`Petition, 31; Ex. 1228, ¶43.
`
`In the grounds section (pp. 42-49), the Petition provides an annotated Figure
`
`5 (p. 42) and, referring to the “switcher” limitation, states: “Kwak discloses this
`
`limitation. Kwak discloses a switcher (highlighted in yellow):”
`
`
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`U.S. Patent No. 8,698,558
`Ex. 1211 at 2668 (“Fig. 5. Hybrid switching amplifier with the feedforward path.”)
`
`Petition, 42; Ex. 1228, ¶44.
`
`The Petition then continues: “The switcher adds an offset to the input
`
`current, which will ultimately generate a larger supply current via the inductor
`
`than without the offset,” (Petition, 43) and points explicitly to the feed forward
`
`path of Fig. 5. See, Id.:
`
`Kwak discloses that the driver AF (highlighted in orange) supplies
`an increase in current—i.e., an offset current—in a “feed forward”
`path. Ex. 1211 at 2668 (“If we add a feedforward path, like the one
`shown in Fig. 5, the input signal can directly control the switching
`amplifier. Such a path is faster than the feedback current path formed
`by sensing the output current of the linear amplifier.”); id. at 2668-69
`(“the gain of the feedforward path AF(s)”).
`
`The Petition then explains where in Fig. 5, Kwak’s switcher adds the offset
`
`to the input current. See, Petition, 43:
`
`The offset current is added to the sensed signal by the summing
`circuit (Σ, outlined in brown), and the summing circuit’s output is
`sent to an integrator AI(s) (the left) triangle outlined in red, labeled
`with the integral sign ∫).
`
`The Petition also explains that “Figure 5 shows how the added offset
`
`current increases the supply current provided via the inductor.” Petition, 45.
`
`Therefore, the Petition explains that Figure 5 of Kwak alone anticipates
`
`claim 15. Because PO is simply wrong that Petitioner relies on Kwak’s Figure 6
`
`for this claim requirement, its argument should be rejected. Ex. 1228, ¶48.
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`2. Figure 6 Shows A Detailed Implementation of a Figure 5
`In any case, PO is also wrong that “Kwak [] describes Figures 5 and 6 as
`
`different embodiments.” POR, 17. PO argues that “Figure 6 illustrates a hybrid
`
`switching amplifier that employs a third-order ripple filter and current feedback not
`
`included in Figure 5, and replaces the summer and integrator of Figure 5 with a
`
`combined ‘summing circuit and integrator’ that has three inputs instead of two and
`
`operates in a different manner.” Ex. 1228, ¶49.