Belden Inc. v. BERK-TEK LLC, Cross-Appellant 2014-1575, -1576 Appeals from the United States Patent

United States Court of Appeals
for the Federal Circuit
______________________
BELDEN INC.,
Appellant
v.
BERK-TEK LLC,
Cross-Appellant
______________________
2014-1575, -1576
______________________
Appeals from the United States Patent and Trade-
mark Office, Patent Trial and Appeal Board in No.
IPR2013-00057.
______________________
Decided: November 5, 2015
______________________
MATTHEW B. L OWRIE, Foley & Lardner LLP, Boston,
MA, argued for appellant. Also represented by MATTHEW
AMBROS , AARON W. M OORE.
J AMES S. BLANK, Kaye Scholer LLP, New York, NY,
argued for cross-appellant. Also represented by BENJAMIN
C. HSING, D AVID S OOFIAN; G REGORY C. ANTRIM , J OSEPH
SOFER, Sofer & Haroun, LLP, New York, NY.
F RANCES L YNCH , Office of the Solicitor, United States
Patent and Trademark Office, Alexandria, VA, argued for
intervenor Michelle K. Lee. Also represented by N ATHAN

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BELDEN INC. v. BERK- TEK LLC 2
K. K ELLEY , T HOMAS W. K RAUSE, ROBERT J. MCMANUS ,
SCOTT WEIDENFELLER .
______________________
Before N EWMAN, D YK, and T ARANTO, Circuit Judges.
T ARANTO, Circuit Judge.
Belden Inc. owns U.S. Patent No. 6,074,503, which
discloses and claims a method for making a communica-
tions cable. On a petition for inter partes review under 35
U.S.C. § 311 et seq. filed by the predecessor of Berk-Tek
LLC, the Patent and Trademark Office’s Patent Trial and
Appeal Board instituted a review and later reached a
mixed decision: it rejected claims 1–4 of the ’503 patent
for obviousness, while confirming claims 5 and 6. We now
affirm the rejection of claims 1–4 and reverse the uphold-
ing of claims 5 and 6. We also reject Belden’s contention
that the Board denied it procedural rights in the review.
BACKGROUND
Belden and Berk-Tek compete in making and selling
telecommunications cable and cabling systems. The ’503
patent, issued on June 13, 2000, discloses a method of
making a cable by passing a core and conducting wires
through one or more dies, bunching the wires into grooves
on the core, twisting the bunch to close the cable, and
jacketing the entire assembly. These figures show an
assembly described as containing three dies (403, 411,
413) and a cross-section of a resulting cable (200):

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BELDEN INC. v. BERK- TEK LLC 4
’503 patent, col. 6, lines 4–17.
Belden groups claim 4 with claim 1 for analysis.
Claim 4, dependent on claim 1, adds an “extrusion” re-
quirement: during the passing step, “extruding the core so
that the surface features thereof align with the plurality
of transmission media.” Id., col. 6, lines 28–31.
Belden groups claims 2 and 3 for analysis. Claim 2
requires, “before passing the transmission media and the
core through the first die, passing the transmission media
and the core through a third die which generally centers
the core relative to the plurality of transmission media.”
Id., col. 6, lines 18–22 (emphases added). That is, claim 2
calls for the large die (“third”) that is upstream of the
small die (“first”) shown in the left figure above—the
“second” being the tube-shaped structure shown there.
Claim 3, dependent on claim 2, claims for the third die
what claim 4 claims for the first: it requires “extruding
the core at a center position relative to the plurality of
transmission media” when the core and media pass
through the third die. Id., col. 6, lines 23–27.
Belden groups claims 5 and 6 for analysis. Claim 5,
dependent on claim 1, requires that the transmission
media be “twisted pairs of insulated conductors.” ’503
patent reexamination certificate, col. 2, lines 7–9 (empha-
sis added). Claim 6, dependent on claim 5, requires four
such pairs. Id., col. 2, lines 10–12.
On November 19, 2012, Berk-Tek’s predecessor,
Nexans, Inc., petitioned for inter partes review of all
claims of the ’503 patent under 35 U.S.C. § 311. The
petition—actually, the corrected petition filed nine days
later, making changes not material here—asserts antici-
pation and obviousness based on seven prior-art refer-

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BELDEN INC. v. BERK- TEK LLC 5
ences.1 On April 16, 2013, the Board, as delegee of the
PTO Director, instituted a review of all claims under
§ 314(a), finding a “reasonable likelihood” that the meth-
ods of all six claims were unpatentable. Nexans, Inc. v.
Belden Technologies Inc., IPR2013-57, 2013 WL 8595538
(PTAB Apr. 16, 2013).
The Board found likely obviousness of the methods of
claims 1 and 4 based on Japanese Patent No. 19910 (JP
’910). It found likely obviousness of the methods of claims
2 and 3 based on JP ’910 together with either U.S. Patent
No. 4,393,582 (US ’582) or Japanese Patent No. 76694 (JP
’694). And it found likely obviousness of the methods of
claims 5 and 6 based on JP ’910 together with Canadian
Patent No. 2,058,046 (CA ’046).2
The central reference, JP ’910, describes a method of
making a communication cable, illustrated below. The
method entails extruding a core (thread-like object 1)
through heated rollers (2a–2c) to form four grooves in the
core, located at corners of a square when viewed in cross-
section. The core and four conducting wires (4a–4d) are
fed through a die (wire-splitting board 5), the wires placed
1 The versions of 35 U.S.C. §§ 102 (anticipation)
and 103 (obviousness) that apply here are those preceding
the changes made by the America Invents Act, given the
effective filing dates of the claims of the ’503 patent. See
Leahy-Smith America Invents Act, Pub. L. No. 112–29,
125 Stat. 284, 293 (2011).
2 The Board also found likely anticipation of claims
1 and 2 by US ’582, but in its final written decision, it
rejected anticipation, so we do not elaborate on the initial
likely-anticipation finding.

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BELDEN INC. v. BERK- TEK LLC 6
into the grooves on the core, and the assembly bunched,
stranded, and jacketed to form a cable.3
F IG. 1 (JP ’910)
F IG. 4 (JP ’910)
JP ’694 and US ’582 also describe methods of making
a cable or cable core, illustrated below. JP ’694 teaches
passing a group of wires and shielding tape through a
first die (plate 31), then a second die (plate 32), and
finally a set of shaping tubes that wrap the shielding tape
around the wires. JP ’694, col. 4, lines 7–28. US ’582
similarly teaches making a cable core, in which a metallic
tape and two groups of wires are fed through a first die
(plate 67) and a second die (plate 71). ’582 patent, col. 5,
lines 1–33.
3 JP ’910 describes “S-Z” stranding, which involves
alternately twisting in one direction, then the other. The
name reflects the difference in the resulting helices
viewed from outside: “S” has a diagonal from northwest to
southeast, “Z” from southwest to northeast.

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BELDEN INC. v. BERK- TEK LLC 7
F IG. 1 (JP ’694)
F IG. 1 (US ’582)
CA ’046 describes a telecommunications cable contain-
ing twisted pairs of conducting wires, separated by a
spacer to minimize cross talk. The patent illustrates
different spacers separating four twisted pairs of wires.
CA ’046, col. 3, line 36 to col. 4, line 37.
F IG. 2 (CA ’046) F IG 3. (CA ’046)
Among the Board’s preliminary determinations in its
Institution Decision are the following. (We discuss only

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BELDEN INC. v. BERK- TEK LLC 8
claims 1, 2, and 5, there being no separate arguments for
claims 4, 3, and 6.) As to claim 1, the Board determined
that “JP ’910 articulates a special need to have the wires
aligned at precise locations on the core during stranding
after passing through wire-splitting board 5” and, based
on that need, “one with ordinary skill in the art would
have known that the passage of core 1 through wire-
splitting board 5 preferably should be made such that
twisting of the core causing misalignment of the wires
would be prevented.” Nexans, 2013 WL 8595538 at *14.
As to claim 2, the Board found that “each of [US] ’582 and
JP ’694 discloses the concept of an additional die which
centers, in a general manner, the core relative to the
plurality of transmission media,” id., and that “[i]nserting
an additional die upstream of wire-splitting board 5 of the
assembly of JP ’910 involves merely a predictable use of a
prior art element disclosed in each of [US] ’582 and JP
’694, to achieve the same advantage[ou]s result.” Id. at
*15. As to claim 5, the Board determined that CA ’046
discloses that “a telecommunication cable is constructed
normally with one or more core units each of which is
conventionally a twisted pair of conductors,” id. at *17,
and that, because “JP ’910 is directed to a method of
manufacturing insulated communication cables,” a skilled
artisan “would have understood that the method of JP
’910 is applicable for use in manufacturing a telecommu-
nications cable” and “would have known to apply the
teaching in CA ’046, about a conductor unit’s being made
conventionally of a twisted pair of conductors, to each
conductor unit 4a, 4b, 4c, and 4d, in JP ’910.” Id. at *18.
The review having been instituted, Belden submitted
its Patent Owner Response on June 24, 2013, attaching a
declaration from its expert, William T. Clark, who is a
named inventor on the ’503 patent and many other ca-
bling patents. Berk-Tek submitted its Reply on August
26, 2013, attaching a declaration from its expert, Les

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BELDEN INC. v. BERK- TEK LLC 9
Baxter. Berk-Tek had attached no declaration to its
Petition.
Belden orally opposed receipt of Mr. Baxter’s declara-
tion with the Reply, arguing that it had no opportunity to
respond. On September 10, 2013, the Board noted that its
regulations permitted Belden to cross-examine Mr. Bax-
ter, see 37 C.F.R. § 42.51(b)(1)(ii), and that Belden could
move to file non-argumentative observations (up to five
pages) calling the Board’s attention to relevant aspects of
the cross-examination. The Board also “cautioned” Berk-
Tek that, if its Reply “includes material it should have
submitted together with its Petition, the Board may
decline the entirety of the Reply,” and the Board gave
Belden “two days to consider whether to file a Revised
Reply”—only to remove material, not add any. J.A. 876;
see Office Patent Trial Practice Guide, 77 Fed. Reg.
48,756, 48,767 (Aug. 14, 2012) (Reply material is limited
to responsive matter; whole Reply may be rejected if any
part is improper).
On September 12, 2013, Berk-Tek submitted a revised
Reply. On October 17, 2013, after taking Mr. Baxter’s
deposition, Belden filed a motion for observations on what
Mr. Baxter had said. The same day, Belden moved to
exclude Mr. Baxter’s declaration and accompanying
exhibits, arguing that portions of Mr. Baxter’s declaration
were not responsive to Mr. Clark’s declaration and that
Mr. Baxter’s declaration contained arguments and evi-
dence necessary for the prima facie case of obviousness.
Berk-Tek opposed the motion, and Belden replied.
On the merits, Belden focused its argument as to
claim 1 on the prevention-of-twisting element. It argued
that JP ’910 does not suggest configuring board 5 to
prevent twisting, that board 5 would not have been able
to grip the core in JP ’910, at least not without producing
friction that would have deformed the core, and that any
tension placed on the core during the cable-making pro-

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BELDEN INC. v. BERK- TEK LLC 10
cess would already have been relieved in JP ’910 by its
(alternating-direction) stranding step. As to claim 2,
Belden argued that JP ’910 did not suggest adding a third
die to its method, Berk-Tek had submitted no evidence
showing a reason to combine the third die of US ’582 or
JP ’694 with the JP ’910 method, and that a skilled arti-
san would have viewed adding a third die to JP ’910 as
only increasing stress without any apparent benefit. As
to claim 5, Belden argued that JP ’910 teaches away from
making a cable with individually insulated twisted pairs,
particularly because using insulated conductors would
render JP ’910’s jacketing step redundant and “would
destroy the circular shape of JP ’910’s ‘quad’ wire.” J.A.
586.
Berk-Tek, in its Reply, countered Belden’s arguments.
As to claim 1, Berk-Tek argued that JP ’910’s requirement
that each conducting wire fall into its corresponding
groove on the core made it imperative to prevent twisting
of the core, that there was no reason to doubt board 5’s
ability to grip the core, and that a skilled artisan would
choose an appropriate polymer, and use cooling after
extrusion, to avoid friction-caused deformation of the core.
As to claim 2, Berk-Tek reiterated the need to prevent
twisting and argued that using extra dies to align and
alleviate stress in cable manufacturing is routine. As to
claim 5, Berk-Tek argued that a skilled artisan, making
any cable by joining transmission media with a separator
and stranding the group, as in CA ’046, would have been
motivated to use a die to align the separator and media
and prevent back twisting, as taught by JP ’910.
The Board agreed with Berk-Tek as to claims 1–4 and
with Belden as to claims 5–6. Berk-Tek, LLC v. Belden
Inc., IPR2013-57, 2014 WL 1253012 (PTAB Mar. 18,
2014) (Final Written Decision). As to claim 1: The Board
concluded that, “by teaching alignment of the grooves and
the conductors at board 5, JP ’910 suggests using board 5
to prevent twisting motion of core 1. That is, a person of

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BELDEN INC. v. BERK- TEK LLC 11
ordinary skill in the art would have recognized that
preventing twisting motion of core 1 in relation to board 5
would maintain alignment between” the grooves and
conductors “in accordance with the teaching of JP ’910.”
Id. at *13. As to claim 2: The Board concluded that US
’582 and JP ’694 each teach “the benefit of a third die,”
stating that adding a third die to JP ’910 would have
“involve[d] merely a predictable use of a prior art element
. . . to perform the same function it was known to perform
and to yield no more than one of ordinary skill would
expect from such use.” Id. at *19–20. As to claim 5: The
Board determined that “JP ’910 cannot be understood
reasonably as teaching or suggesting a method of manu-
facturing all types of twisted cables having a separator,”
in particular “conventional twisted cable . . . that includes
twisted pairs of individually-insulated conductors.” Id. at
*23 (emphasis added). The Board faulted Berk-Tek for
giving no “apparent reason to combine the known ele-
ments of JP ’910 and CA ’046.” Id.
The Board also denied Belden’s motion to exclude. It
concluded that Mr. Baxter’s declaration “fairly re-
spond[ed] to Mr. Clark’s declaration” and was unneces-
sary for Berk-Tek to establish a prima facie case of
obviousness. Id. at *26.
Belden appeals the cancellation of claims 1–4 and the
denial of its motion to exclude. Berk-Tek appeals the
upholding of claims 5 and 6. Both appeals are authorized
by 35 U.S.C. § 319. We have jurisdiction under 28 U.S.C.
§ 1295(a)(4)(A).
D ISCUSSION
We begin with a review of the substantive challenges
to the Board’s determinations on the evidence and argu-
ments presented to and considered by it. We then review
Belden’s procedural challenge to the Board’s decision to
allow Berk-Tek’s Reply evidence.

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BELDEN INC. v. BERK- TEK LLC 12
A
Whether a claimed invention would have been obvious
is a question of law, based on factual determinations
regarding the scope and content of the prior art, differ-
ences between the prior art and the claims at issue, the
level of ordinary skill in the pertinent art, the motivations
to modify or combine prior art, and any objective indicia of
non-obviousness. Randall Mfg. v. Rea, 733 F.3d 1355,
1362 (Fed. Cir. 2013). We review the Board’s compliance
with the governing legal standards de novo and its under-
lying factual determinations for substantial evidence. Id.
1
In challenging the cancellation of claim 1 for obvious-
ness, Belden argues that JP ’910 does not teach making
cables, but only transmission lines (a component of a
cable), and it disputes the Board’s finding of a motivation
to use board 5 in JP ’910 to prevent the twisting of core 1.
See ’503 patent, col. 1, lines 4–8. Neither argument has
merit.
The Board found that “[t]he purpose of the invention
of JP ’910 ‘is to provide a method of manufacturing plastic
insulated communication cable.’ ” Berk-Tek, 2014 WL
1253012, at *11 (quoting JP ’910 at ¶ 3); see Nexans, 2013
WL 8595538, at *12 (“JP ’910 discloses an assembly for
manufacturing insulated communication cables.”). That
finding is supported by substantial evidence. The title of
JP ’910 is: “A method of manufacturing plastic insulated
communication cables.” JP ’910 at ¶ 1. JP ’910 claims
“[a] method of manufacturing plastic insulated cables.”
Id. at ¶ 2. The patent further explains: “The present
invention relates to a method of manufacturing plastic
insulated communication cables.” Id. at ¶ 3. Belden
argues that, despite those descriptions, JP ’910 teaches
only the making of quads, which themselves are not
cables but mere components of cables. But the claims of
the ’503 patent do not so limit the meaning of “cable” to a

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BELDEN INC. v. BERK- TEK LLC 13
category that excludes quads, and Belden does not dispute
that it never argued for a construction of “cable” before
the Board. Thus, Belden’s argument that JP ’910 does not
describe a method of making communication cables fails.
The Board also found that, by teaching the need for
alignment of the conductors and core at board 5, JP ’910
suggested using board 5 to prevent the twisting of core 1.
Although the Board twice stated that “board 5 could have
been used to prevent twisting of core 1 by one with ordi-
nary skill in the art exercising ordinary creativity,” Berk-
Tek, 2014 WL 1253012, at *13, *17 (emphasis added), it
did not stop there—and properly so, because obviousness
concerns whether a skilled artisan not only could have
made but would have been motivated to make the combi-
nations or modifications of prior art to arrive at the
claimed invention. See InTouch Technologies, Inc. v. VGO
Communications, Inc., 751 F.3d 1327, 1352 (Fed. Cir.
2014). The Board found that “[v]iewed as a whole, JP ’910
does teach the importance of avoiding any misplacement
of the conductors in relation to the core,” Berk-Tek, 2014
WL 1253012, at *14; “[a] person with ordinary skill in the
art would have recognized that such alignment of the
grooves on core 1 with the fixed positions of the conduc-
tors on board 5 cannot be maintained if core 1 twists in
relation to board 5,” id. at *13; and “[t]herefore, by teach-
ing alignment of the grooves and the conductors at board
5, JP ’910 suggests using board 5 to prevent twisting
motion of core 1,” id. And the Board reiterated its earlier
finding in its Institution Decision: “ ‘Given that JP ’910
articulates a special need to have the wires aligned at
precise locations on the core during stranding after pass-
ing through wire-splitting board 5, one with ordinary skill
in the art would have known that the passage of core 1
through wire-splitting board 5 preferably should be made
such that twisting of the core causing misalignment of the
wires would be prevented.’ ” Id. at *14 (emphasis added).
In support of those affirmative findings, the Board re-

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BELDEN INC. v. BERK- TEK LLC 14
peatedly cited the Petition. Id. at *13, *14, *15 (relying
on J.A. 146–47).
Those findings suffice to show that claim 1 (and claim
4) must fall, because the findings are supported by sub-
stantial evidence. In the circumstances here, involving a
simple point in a mechanical field and one very close piece
of prior art, the Board was entitled to rely on its own
reading of JP ’910—supported by the Petition’s observa-
tions about it—to find that a skilled artisan would have
understood the importance of aligning the core and con-
ductors and the connection between achieving such
alignment and preventing the core from twisting at the
aligning die. And the Board also had substantial evidence
on which to reject Belden’s contrary arguments.
Mr. Baxter responded to Belden’s suggestion that a
skilled artisan would have had no reason to modify board
5 of JP ’910 to prevent twisting, as required by claim 1 of
Belden’s patent. He stated that JP ’910 and Belden’s
patent address the same problem of aligning conductors
with grooves in a cable’s core; that JP ’910’s touted elimi-
nation of “back-stranding” of wires—imparting a prepara-
tory twist to the wires before cable manufacturing to
compensate for twisting during cabling, JP ’910 at ¶ 3—
made it evident that twisting should be prevented by
another means; and that a skilled artisan would have
seen that the die (board 5 in JP ’910) should be used to
control twisting. Mr. Baxter also plausibly explained why
the S-Z stranding in JP ’910 might increase the need to
prevent twisting at the die, contrary to Belden’s sugges-
tions that the alternating-direction stranding would by
itself so clearly prevent misalignment of the core with the
conducting wires that there was no reason to contemplate
using board 5 to prevent twisting. And in answer to
Belden’s argument about friction-caused deformation of
the core if the die hugged the core to prevent its twisting,
Mr. Baxter stated that a skilled artisan would have
chosen a polymer with the right resistance to heat and a

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BELDEN INC. v. BERK- TEK LLC 15
cooling process after extrusion. The Board thus had an
ample basis for its obviousness determination as to claims
1 and 4.
2
As to claims 2 and 3, Belden does not dispute that
both US ’582 and JP ’694 disclose a third die. See US ’582
Fig. 1; id. Fig. 3; id., col. 5, lines 20–33; JP ’694 Fig. 2; id.,
col. 4, lines 7–12. Belden disputes only the Board’s find-
ing of a reason to combine a third die with the method of
JP ’910.
The Board found that “die 71 in [US ’582] and die 31
in JP ’694 each suggests passing the transmission media
and the core through a third die that generally centers the
core relative to the plurality of transmission media,” Berk-
Tek, 2014 WL 1253012 at *18, and that each patent
“teaches the benefit of a third die,” id. at *19. It also
found that “a person of ordinary skill in the art would
have added a third die, as recited in claim 2, in order to
align further the cable components.” Id. The Board cited
the Petition’s argument to that effect. Id. at *18, *19
(citing J.A. 154).
Significantly, it was only in the context of those find-
ings about why a skilled artisan would have had reason to
add a third die that the Board quoted the Supreme
Court’s reference to a “ predictable variation” in KSR Int’l
Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007). Berk-Tek,
2014 WL 1253012 at *19. The Supreme Court’s passage
does not establish that it suffices for obviousness that a
variation of the prior art would predictably work, but
requires consideration of whether, in light of factors such
as “design incentives and other market forces,” the hypo-
thetical skilled artisan would recognize the potential
benefits and pursue the variation. KSR, 550 U.S. at 417.
In the present case, the Board, in its overall analysis,
made the required full inquiry.

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BELDEN INC. v. BERK- TEK LLC 16
The Board’s findings suffice to show that claim 2 (and
claim 3) must fall, because the findings are supported by
substantial evidence. Here, as with claim 1, the prior art
is close enough and plain enough that, with even an
abbreviated argument in the Petition, the Board could
determine that a skilled artisan would see the benefit of
adding a third die to enhance alignment. And here, as
with claim 1, the Board had sufficient evidence to reject
Belden’s arguments to the contrary.
In response to Belden’s argument that a skilled arti-
san would have no reason to add a third die to JP ’910,
though one is undisputedly shown in US ’582 and JP ’694,
Mr. Baxter explained that a third die upstream from the
first die would have a “benefit” of “ ‘more accurately
aligning the input wires with the rest of the machine with
less or lessened tensions and with better angles, allowing
the supply reels to be located farther from the wire-
splitting board.’ ” Berk-Tek, 2014 WL 1253012, at *19
(quoting J.A. 706). Mr. Baxter also responded to Belden’s
argument that a third die would increase friction and
drag, harming a fragile core. He stated that fragility was
speculative and that an upstream die would be “ ‘looser
fitting.’ ” Id. (quoting J.A. 706). Berk-Tek, citing the
Baxter declaration, argued in its Reply that a third die
was a “ ‘routine’ ” way of improving alignments and less-
ening tensions. Id. (quoting J.A. 897). The Board thus
had an ample basis for its obviousness determination as
to claims 2 and 3.
3
As to claims 5 and 6, Berk-Tek argues that a person of
ordinary skill in the art seeking to manufacture cables
disclosed in CA ’046—with four insulated twisted pairs
and a separator—would have been motivated to use the
method of JP ’910 to solve the alignment issues common
to manufacturing the cables in both prior-art sources.
Even giving the Board the deference it is due under the

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BELDEN INC. v. BERK- TEK LLC 17
substantial-evidence standard of review of factual find-
ings, we agree that the record requires the finding Berk-
Tek urges. The Board’s contrary finding rests on legal
errors.
There is no meaningful dispute here, and the Board
did not deny, that the two pieces of prior art in combina-
tion teach or suggest the methods of claims 5 and 6. The
dispute concerns motivation to combine. The Petition and
the Institution Decision reveal the two related ways in
which that issue was presented and considered: whether a
skilled artisan would substitute the twisted pairs of CA
’046 into the method of JP ’910; alternatively, whether a
skilled artisan making the cable of CA ’046 would look to
the JP ’910 method to make it. The brief discussion in the
Petition suggests both views of the matter. J.A. 148–49
(“CA ’046 . . . in view of . . . JP ’910 . . . invalidates claims
3 through 5”); J.A. 155 (“JP ’910 uses single conductors
(4a-4d), but it is known to likewise use twisted pairs with
a cross shaped separator—see for example CA ’046”). The
Board’s Institution Decision does so as well: “[O]ne with
ordinary skill in the art would have understood that the
method of JP ’910 is applicable for use in manufacturing a
telecommunications cable. Accordingly, one with ordinary
skill in the art would have known to apply the teaching in
CA ’046, about a conductor unit’s being made convention-
ally of a twisted pair of conductors, to each conductor unit
4a, 4b, 4c, and 4d, in JP ’910.” Nexans, 2013 WL 8595538,
at *18.
As the Board found, it is “undisputed that CA ’046
discloses ‘a helically twisted cable.’ ” Berk-Tek, 2014 WL
1253012, at *24. There is no dispute that the twisted
pairs in CA ’046 need to fit into the notches of (i.e., be
aligned with) the separator, as shown in the two figures
from CA ’046 reproduced above, for the resulting cable to
be made. And the Board correctly recognized in its dis-
cussion of claims 1 and 2 that JP ’910 clearly teaches the
importance of aligning conductors with a separator (core),

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BELDEN INC. v. BERK- TEK LLC 18
and suggests doing so with a die to prevent twisting of the
separator, before they are all bunched together for twist-
ing in a stranding device. That evidence points clearly
toward a motivation of a skilled artisan to arrive at the
methods of claims 5 and 6 based on JP ’910 and CA ’046,
as the Board reasoned in its preliminary determination in
the Institution Decision.
None of the Board’s reasons for concluding otherwise
in its Final Written Decision withstands scrutiny through
the lens of governing law. The Board’s first reason was
that JP ’910 shows only conductors that are not individu-
ally insulated, so that “one of ordinary skill, tasked to
produce the conventional twisted cable of CA ’046, would
not have been motivated by the teachings of JP ’910
simply to substitute twisted pairs of insulated conductors
for the bare metal conductors in the method of JP ’910.”
Berk-Tek, 2014 WL 1253012, at *23 (emphasis in origi-
nal). But JP ’910 plainly discloses the need to align the
conducting wires with the core and how to do so, as the
Board recognized in its analysis of claims 1 and 4, id. at
*13–14. The alignment problem and solution do not
depend on whether the wires are insulated. The Board’s
disregard of the insulation-independent alignment teach-
ing of JP ’910 violates the principle that “[a] reference
must be considered for everything it teaches by way of
technology and is not limited to the particular invention it
is describing and attempting to protect.” EWP Corp. v.
Reliance Universal Inc., 755 F.2d 898, 907 (Fed. Cir. 1985)
(emphases in original); see In re Applied Materials, Inc.,
692 F.3d 1289, 1298 (Fed. Cir. 2012).
The Board next reasoned that “Berk-Tek ha[d] not
explained why a person of ordinary skill in the art would
have had sufficient reason to use the S-Z stranding step of
JP ’910 to manufacture the helically-twisted cable of CA
’046,” stating that “the S-Z stranding step of JP ’910 is
inconsistent with production of a helically-twisted cable.”
Berk-Tek, 2014 WL 1253012, at *24. That reasoning

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BELDEN INC. v. BERK- TEK LLC 19
makes the same mistake we have just noted regarding the
Board’s reliance on the lack of insulation of the individual
conductors in JP ’910: it disregards the evident independ-
ent force of JP ’910’s teaching of the alignment problem
and solution. The Board did not find, and could not
reasonably find, that the significance to claims 5 and 6 of
JP ’910’s alignment teaching is dependent on the particu-
lar method of stranding described in JP ’910, any more
than it is dependent on insulation of individual wires.
The claims of Belden’s patent call simply for “twisting”
the assembly, without restrictions on the particular kind
of twisting. And Belden’s expert, Mr. Clark, did not rely
on the S-Z stranding method of JP ’910 in urging the
validity of claims 5 and 6.
The Board, returning to its focus on insulation of in-
dividual conductors, further reasoned: “Berk-Tek also has
not explained why a person of ordinary skill in the art
would have had sufficient reason to use the final jacket-
ing/extrusion step of JP ’910, which serves to insulate
electrically the bare-metal conductors of JP ’910, to manu-
facture a cable comprising twisted pairs of individually-
insulated conductors that do not require additional elec-
trical insulation.” Id. The Board found no answer to
Belden’s statement that the final jacketing step, if the
conductors themselves were insulated, would be “ ‘redun-
dant.’ ” Id. But that logic misconstrues the claim lan-
guage and overlooks on-point evidence.
The claim language concerning the final jacketing
step does not require that the jacket be insulating at all.
And it is clear from the Belden patent and at least
CA ’046 that the jacketing step serves a function not
dependent on adding insulation. The evident function is
to hold the assembly together to form a cable, and hold its
components in place, whether or not the component
conductors are insulated. Thus, Belden’s patent itself
declares that “[c]onventional designs of data grade tele-
communications cables for installation in plenum cham-

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BELDEN INC. v. BERK- TEK LLC 20
bers have a low smoke generating jacket material . . .
surrounding a core of twisted conductor pairs, each con-
ductor individually insulated with a[n] . . . insulation
layer.” ’503 patent, col. 2, lines 24–30 (emphases added);
see id., col. 4, lines 22–25; id., col. 2, lines 59–64 (“[T]he
cable includes . . . an outer jacket maintaining the plurali-
ty of data transmission media in position with respect to
the core.”). CA ’046 also teaches this purpose of jacketing
insulated twisted pairs. CA ’046, col. 3, line 16 to col. 4,
line 4 (“[I]n a cable 20, the jacket 12 surrounds four pairs
14 of insulated conductors 16 which are held in controlled
distances apart, as they extend in stranded condition
along the cable, by a spacer means in the form of a central
core member 20.”) (emphasis added).
Finally, the Board made a passing reference to
“Belden’s argument that modifying the cable of JP ’910 to
include twisted pairs would ‘destroy the circular shape of
JP ’910’s “quad” wire.’ ” Berk-Tek, 2014 WL 1253012, at
*24. But nothing in the ’503 patent describes or claims
the circularity of the cable produced by its method. And
neither JP ’910 nor CA ’046 ascribes any significance to
the shape of the cables they disclose. The Board identi-
fied, and we see, no reason that the teaching of JP ’910
about the alignment problem and solution is inapplicable
to making the cables of CA ’046 even if the resulting
cable’s cross-section is not circular.
In short, the record is one-sided on the proper ques-
tion of whether JP ’910 taught a solution to the problem of
aligning cable components that a skilled artisan would
have been motivated to use in making CA ’046’s cables.
The Board erred in determining that Berk-Tek had not
proven the obviousness of the methods of claims 5 and 6
of the ’503 patent by a preponderance of the evidence.
B
Belden challenges the Board’s denial of the motion to
exclude the Baxter declaration that Berk-Tek submitted

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BELDEN INC. v. BERK- TEK LLC 21
with its Reply. It argues that the Board violated a regula-
tion governing evidence submitted with a Reply and two
aspects of the Patent Office Trial Practice Guide, thereby
relying on evidence to which Belden lacked a fair oppor-
tunity to respond. We review the Board’s evidentiary
ruling for abuse of discretion, which may be found if the
Board violated governing law. Chen v. Bouchard, 347
F.3d 1299, 1307 (Fed. Cir. 2003). We reject Belden’s
contentions.
1
Belden asserts that Berk-Tek’s filing of the Baxter
declaration violated 37 C.F.R. § 42.23(b), which states
that “[a] reply may only respond to arguments raised in
the corresponding opposition or patent owner response.”
The Board found no violation, concluding that Mr. Bax-
ter’s declaration “fairly responds to Mr. Clark’s declara-
tion” and is “generally . . . in fair reply to Mr. Clark’s
declaration and/or Belden’s response to the revised peti-
tion.” Berk-Tek, 2014 WL 1253012, at *26. We see no
error in that ruling.
Each of the points that Mr. Baxter made in his decla-
ration responds to a statement made in Mr. Clark’s decla-
ration. Mr. Baxter’s discussion of claims 1 and 4 of
Belden’s patent is representative. After quoting Mr.
Clark’s argument that JP ’910 does not teach a method of
making communication cables, the Baxter declaration
responds with reference to JP ’910 and a supporting
exhibit. J.A. 692. After summarizing Mr. Clark’s argu-
ment about JP ’910’s teaching of a need to control twisting
of the core and the elimination of back twisting, the
Baxter declaration explains what JP ’910 means by “back
stranding” and distinguishes back stranding from the
problem of “back-twisting” addressed by Belden’s patent
and JP ’910. J.A. 692–97. The Baxter declaration then
similarly summarizes and responds to Mr. Clark’s state-
ments regarding S-Z stranding in JP ’910, the utility of

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BELDEN INC. v. BERK- TEK LLC 22
board 5 in preventing twisting of the core, the deformabil-
ity of the core in JP ’910, and the ability of board 5 to grip
the core. J.A. 697–705. The Baxter declaration’s discus-
sion of claims 2, 3, 5, and 6 follows a similar approach.
J.A. 706–09. The Board did not abuse its discretion in
concluding that, as relevant here, Mr. Baxter’s declara-
tion fairly responds only to arguments made in Mr.
Clark’s declaration and Belden’s response.
2
Belden relies on a passage from the Patent Office
Trial Practice Guide that elaborates on the regulation
that limits replies to responsive arguments, excluding
new issues. The passage states that “[e]xamples of indi-
cations that a new issue has been raised in a reply include
new evidence necessary to make out a prima facie case for
the . . . unpatentability of an original . . . claim.” 77 Fed.
Reg. at 48,767. Belden argues that the Baxter declara-
tion, submitted with Berk-Tek’s Reply, was necessary to
make out the prima facie case of obviousness and for that
reason should have been excluded.
Although the Board has recognized that the Guide
merely “provides guidance,” Innolux Corp. v. Semiconduc-
tor Energy Lab. Co., IPR2013-60, 2013 WL 8595541, at *3
(PTAB May 3, 2013), the Board did not reject Belden’s
contention on the ground that the Guide is not a binding
regulation. Rather, the Board rejected Belden’s premise
“that Mr. Baxter’s testimony was necessary for Berk-Tek
to establish a prima facie case.” Berk-Tek, 2014 WL
1253012, at *26. We see no error in that ruling.4
4 The same Guide passage includes, among its
“[e]xamples of indications that a new issue has been
raised in a reply,” “new evidence that could have been
presented in a prior filing.” 77 Fed. Reg. at 48,767. That

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BELDEN INC. v. BERK- TEK LLC 23
Our earlier discussion of the merits of the obviousness
issues shows how the prior art itself, together with the
Petition, sufficed to supply a prima facie case of obvious-
ness—as confirmed by the Institution Decision. For
example, as to claim 1, the Board found that JP ’910 itself
articulates a special need to have the wires aligned with
the grooves on the core after passing through board 5, and
that one with ordinary skill in the art would have known
that board 5 could and preferably should be made to
prevent twisting of the core that would cause misalign-
ment. Berk-Tek, 2014 WL 1253012, at *14–15; Nexans,
2013 WL 8595538, at *14. As to claim 2, the Board found
that both US ’582 and JP ’694 disclose the advantage of
using an additional die to center the core relative to the
transmission media, and that a person of skill in the art
would recognize that the same benefit predictably would
be achieved by using a third die in the method of JP ’910.
Berk-Tek, 2014 WL 1253012, at *18–19; Nexans, 2013 WL
8595538, at *15. Such findings are well supported in the
prior-art documents themselves, as are those which we
have concluded show obviousness of the methods of claims
5 and 6.
To be sure, the Board cited Mr. Baxter’s declaration in
its Final Written Decision—mostly in explaining why it
was rejecting Belden’s arguments, but partly in stating
the affirmative reasons to find the motivation required for
a prima facie case. But such citations do not mean that
the Baxter declaration was “necessary” for the prima facie
case. Evidence admitted in rebuttal to respond to the
patent owner’s criticisms will commonly confirm the
prima facie case. That does not make it necessary to the
prima facie case. And nothing required the Board to write
language—which, read literally, might cover most respon-
sive evidence—is not independently significant here.

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BELDEN INC. v. BERK- TEK LLC 24
its opinion to separate the material offered by Berk-Tek
at different stages of the proceeding.
No rule requires a Petition to be accompanied by any
declaration, let alone one from an expert guiding the
Board as to how it should read prior art. What the Board
can find without an expert depends on the prior art in-
volved in a particular case. Even in court, we have said,
“expert testimony is not required when the references and
the invention are easily understandable.” Wyers v. Master
Lock Co., 616 F.3d 1231, 1242 (Fed. Cir. 2010). And
Board members, because of expertise, may more often find
it easier to understand and soundly explain the teachings
and suggestions of prior art without expert assistance. In
the present case, which is all we address, we conclude
that the Baxter declaration was not necessary for the
prima facie case of obviousness.
3
Belden cites the Patent Trial Guide’s statement that
“[t]he Board will not attempt to sort proper from improper
portions of the reply.” 77 Fed. Reg. at 48,767. It argues
on that basis that the Board had to exclude Berk-Tek’s
entire Reply and supporting material if any portion was
improper. But Belden has identified no part of the Reply
and supporting declaration that is improper and material
to the Board’s ruling. Nothing in the Guide requires
wholesale exclusion in such circumstances. More general-
ly, the Guide cannot fairly be read to do more than put
the public on notice that the Board may, in its discretion,
refuse to consider a Reply if any part is improper. Here,
the Board warned Berk-Tek and gave it an opportunity to
truncate its Reply and supporting submissions to elimi-
nate any improper material. We see no error in that
reasonable course of action.

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BELDEN INC. v. BERK- TEK LLC 25
4
Belden’s broadest contention is that the Board im-
properly relied on new evidence to which Belden had no
opportunity to respond. But Belden provides no argument
on this score that is independent of its specific allegations
of error. We have rejected those allegations, upholding
the Board’s rulings that the Baxter evidence was legiti-
mately responsive to Belden’s arguments and not needed
for a prima facie case of obviousness. In these circum-
stances, and without any other identification of error,
Belden has not established that it was denied its proce-
dural rights.
A patent owner in Belden’s position is undoubtedly
entitled to notice of and a fair opportunity to meet the
grounds of rejection. “The indispensable ingredients of
due process are notice and an opportunity to be heard by
a disinterested decision-maker.” Abbott Labs. v. Cordis
Corp., 710 F.3d 1318, 1328 (Fed. Cir. 2013). And for a
formal adjudication like the one at issue here, the Admin-
istrative Procedure Act requires the PTO to “timely
inform[]” a patent owner of “the matters of fact and law
asserted” in an inter partes review of its patent, 5 U.S.C.
§ 554(b)(3), to give “all interested parties opportunity for
. . . the submission and consideration of facts [and] argu-
ments . . . [and] hearing and decision on notice,” § 554(c),
and to permit a party “to submit rebuttal evidence, and to
conduct such cross-examination as may be required for a
full and true disclosure of the facts,” § 556(d). See Bow-
man Transp., Inc. v. Arkansas-Best Freight Sys., Inc., 419
U.S. 281, 288 n.4 (1974); Pension Benefit Guaranty Corp.
v. LTV Corp., 496 U.S. 633, 655 (1990). Section 554(b)(3)
has been applied to mean that “an agency may not change
theories in midstream without giving respondents rea-
sonable notice of the change” and “the opportunity to
present argument under the new theory.” Rodale Press,
Inc. v. FTC, 407 F.2d 1252, 1256–57 (D.C. Cir. 1968). In a
related PTO setting, this court has determined whether

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BELDEN INC. v. BERK- TEK LLC 26
the Board relied on a “new ground of rejection” by asking
“whether applicants have had fair opportunity to react to
the thrust of the rejection.” In re Biedermann, 733 F.3d
329, 337 (Fed. Cir. 2013) (internal quotation marks and
citation omitted).
But the rules and practices of the Board generally
protect against loss of patent rights without the required
notice and opportunity to respond. If there are deficien-
cies in Board rules and practices, none has been estab-
lished as relevant to this case. Nor has Belden identified
a deficiency in the application of Board rules and practic-
es to this case.
The statute provides for inter partes review proceed-
ings to begin with a petition from the challenger. 35
U.S.C. §§ 311, 312(a). The patent owner has the right to
file a preliminary response to argue against the institu-
tion of review. § 313. If a review is instituted, based on a
finding of a reasonable likelihood that the claims do not
meet statutory requirements, the patent owner has the
right to file a post-institution response to defend the
claims. § 316(a)(8). The petitioner also has a right to file
at least one set of written comments. § 316(a)(13). And
both parties have a right to an oral hearing. § 316(a)(10).
The PTO Director has implemented those provisions
through regulations under § 316(a). The regulations
provide for the two patent-owner filings, one before and
one after institution. 37 C.F.R. §§ 42.107(a), 42.120(a).
And they allow the petitioner to reply to the patent own-
er’s post-institution response, but declare that the “reply
may only respond to arguments raised in the correspond-
ing opposition or patent owner response.” § 42.23(b).
Under § 42.51(b)(1)(ii), moreover, a party may cross-
examine an affiant who has submitted testimony pre-
pared for the review. Under § 42.51(b)(2)(i), a party also
may move for additional discovery. In addition, a party
may move to exclude evidence, whether as improper

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BELDEN INC. v. BERK- TEK LLC 27
under the response-only regulation, under the Trial
Practice Guide’s advice, or on other grounds. § 42.64(c).
The Guide itself provides that, “[i]n the event that cross-
examination occurs after a party has filed its last sub-
stantive paper on an issue, . . . [t]he Board may authorize
the filing of observations” on that cross-examination,
though the observations are to be brief and non-
argumentative. 77 Fed. Reg. at 48,767–68. And for most
regulations governing inter partes review—i.e., those
promulgated under parts 1, 41, and 42 of title 37 of the
Code of Federal Regulations—“[t]he Board may waive or
suspend a requirement . . . and may place conditions on
the waiver or suspension.” 37 C.F.R. § 42.5(b).
Finally, although no rule provides patent owners the
right to file surreplies to a petitioner’s Reply, the Board
has allowed such surreplies in inter partes reviews. See,
e.g., Sensio, Inc. v. Select Brands, Inc., IPR2013-580, 2015
WL 1009189, at *1, *4–7 (PTAB Feb. 9, 2015); Zodiac Pool
Sys., Inc. v. Aqua Prods., Inc., IPR2013-159, 2014 WL
4244016, at *1, *22 (PTAB Aug. 22, 2014); ABB, Inc. v.
ROY-G-BIV Corp., IPR2013-63, 2014 WL 2112556, at *4
(PTAB May 16, 2014). In doing so, the Board has followed
a tradition that pre-dates the America Invents Act. In
proceedings on applications and in interferences, the
Board (or its predecessor) has long granted permission to
file surreplies despite the absence of any regulation
providing for such filings.5
5 For interferences, see, e.g., Tseng v. Doroodian,
Interference No. 104,482, 2002 WL 390537 at *28 (BPAI
2002); Flanders v. Moorman, Interference No. 103,891,
2001 WL 35825814, at *2–4 (BPAI Sept. 26, 2001). For
applications, see, e.g., Ex parte Jang, Appeal No. 2011-
7826, 2012 WL 3186809, at *4 (BPAI July 31, 2012); Ex
parte Wyss, Appeal No. 2011-5375, 2012 WL 3142233, at

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BELDEN INC. v. BERK- TEK LLC 28
Thus, if the petitioner submits a new expert declara-
tion with its Reply, the patent owner can respond in
multiple ways. It can cross-examine the expert and move
to file observations on the cross-examination. It can move
to exclude the declaration. It can dispute the substance of
the declaration at oral hearing before the Board. It can
move for permission to submit a surreply responding to
the declaration’s contents. And it can request that the
Board waive or suspend a regulation that the patent
owner believes impairs its opportunity to respond to the
declaration. The options are not mutually exclusive.
In the foregoing respects, the Board’s rules and prac-
tices establish standards bearing similarities to those
often applied in district-court litigation. See Victor Gold,
28 Fed. Prac. & Proc. Evid. § 6164 (2d ed. 2015). The
tribunal has broad discretion to regulate the presentation
of evidence under Fed. R. Evid. 611(a). Rebuttal evidence
is supposed to be limited to that which is responsive to
the adversary’s evidence: “the traditional principle [is]
that evidence offered to rebut must accomplish the func-
tion of rebuttal; ‘to explain, repel, counteract, or disprove
*1 n.1, *3 (BPAI July 31, 2012); Ex parte Zajchowski,
Appeal No. 2010-6962, 2012 WL 2992507, at *2 (BPAI
July 13, 2012); Ex parte Selvin, Appeal No. 2009-13065,
2010 WL 2070576, at *2 n.8, *3 (BPAI May 21, 2010); Ex
parte Domb, Appeal No. 2008-3664, 2010 WL 2030469, at
*8–10, *12 (BPAI May 20, 2010); Ex parte Frippiat, Ap-
peal No. 2009-10881, 2010 WL 1725736, at *2, *5 (BPAI
Apr. 26, 2010); Ex parte Kringelum, Appeal No. 2008-
3378, 2008 WL 3272056, at *7 (BPAI Aug. 7, 2008); Ex
parte Schultz, Appeal No. 2008-3731, 2008 WL 2856377,
at *6, *9–10 (BPAI July 24, 2008); Ex parte Wells, Appeal
No. 2005-2607, 2005 WL 4779434, at *1 n.2 (BPAI Sept.
23, 2005); Ex parte Yoshida, Appeal No. 1997-61, 1999
WL 33134885, at *1 (BPAI Oct. 18, 1999).

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BELDEN INC. v. BERK- TEK LLC 29
the evidence of the adverse party.’ ” Gold, supra (quoting
United States v. Luschen, 614 F.2d 1164, 1170 (8th Cir.
1980)). Where new enough matter is allowed on rebuttal,
surrebuttal may be allowed, but a proffer of specifics may
be required to justify the additional round of evidentiary
submissions. Gold, supra; Hall v. General Motors Corp.,
647 F.2d 175, 181 (D.C. Cir. 1980); United States v. Sad-
ler, 488 F.2d 434, 435 (5th Cir. 1974). Those standards
are widely employed to provide the required procedural
fairness through careful case-specific application.
Here, the Board held Berk-Tek to the response-only
standard for evidence submitted with a Reply and even
held itself to ensuring that the prima facie case did not
depend on that evidence. It provided for Belden’s cross-
examination of Mr. Baxter and for submission of non-
argumentative observations on that cross-examination. It
accepted Belden’s detailed motion to exclude (and its
reply after Berk-Tek’s response). It provided Belden with
a meaningful opportunity to respond to the propriety of
Mr. Baxter’s evidence submitted with Berk-Tek’s Reply,
in that it granted every request Belden made for consid-
eration of the issue. Belden did not seek to file a surreply,
to file additional observations on its cross-examination, to
make arguments in those observations, or to have the
Board waive any other regulations that it believed pre-
vented it from adequately responding to Mr. Baxter’s
declaration. With no Board denial of concrete, focused
requests before us, we are not prepared to find that
Belden was denied a meaningful opportunity to respond
to the grounds of rejection, and we find no basis for dis-
turbing the Board’s denial of Belden’s motion to exclude.
CONCLUSION
For the foregoing reasons, we affirm the Board’s
determinations that claims 1–4 of the ’503 patent would
have been obvious, reverse the Board’s determination that

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BELDEN INC. v. BERK- TEK LLC 30
claims 5 and 6 would not have been obvious, and affirm
the Board’s denial of Belden’s motion to exclude.
No costs.
AFFIRMED IN PART AND REVERSED IN PART

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