Ex Parte Shiah

Board of Patent Appeals and Interferences

Oct 24, 2007

10631841 (B.P.A.I. Oct. 24, 2007)

UNITED STATES PATENT AND TRADEMARK OFFICE

__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte CHUN SHIAH
__________

Appeal 2007-1647
Application 10/631,841
Technology Center 2800
__________

Decided: October 24, 2007
_________

Before JOSEPH L. DIXON, MAHSHID D. SAADAT, and
ST. JOHN COURTENAY III, Administrative Patent Judges.

COURTENAY, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134(a) from the
Examiner’s rejection of claims 1-42. We have jurisdiction under 35 U.S.C.
§ 6(b). We REVERSE.
Appeal 2007-1647
Application 10/631,841

THE INVENTION
The disclosed invention relates generally to an interface circuit, and
more particularly, to a low jitter input buffer (Specification 1).
Independent claim 1 is illustrative:
1. An input buffer receiver comprising:

a buffer input portion for receiving an input signal, said
buffer input portion comprising a bias node;

a large capacitor coupled between the bias node and a
lower supply voltage for providing a coupling ratio between a
capacitance value of said large capacitor and a capacitance
value of a parasitic capacitor coupled between said bias
node and a ground reference point is approximately equal to
a unity value such that a biasing voltage at said biasing node
follows said lower supply voltage to minimize effects of a
ground noise signal between the lower supply voltage and
the ground reference point; and

a buffer output portion in communication with the buffer
input portion for producing an output signal.

THE REFERENCES
Applicant’s Admitted Prior Art (AAPA), see Fig. 1, labeled “FIG. 1 ─ Prior
Art,” see also pages 61-62, paragraphs 0014-0016.

Rapp US 6,373,328 B2 Apr. 16, 2002

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THE REJECTIONS
Claims 1-42 stand rejected under 35 U.S.C. § 112, first paragraph, for
failing to comply with the written description requirement.1
Claims 1-42 stand rejected under 35 U.S.C. § 112, second paragraph,
as being indefinite for failing to particularly point out and distinctly claim
the subject matter which applicant regards as the invention.
Claims 1-42 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over the teachings of AAPA in view of Rapp.
Rather than repeat the arguments of Appellant or the Examiner, we
make reference to the Brief and the Answer for the respective details thereof.

ANALYSIS
35 U.S.C. § 112, first paragraph
We consider first the Examiner’s rejection of claims 1-42 as failing to
comply with the written description requirement under 35 U.S.C. § 112, first
paragraph. Specifically, the Examiner concludes that the following claim
language is unsupported by the original Specification, filed July 31, 2003
(Answer 4 and 8):

1 We note that the Examiner also objected, under 35 U.S.C. § 132(a), to the
amendments filed on Jan. 14, 2005 and June 9, 2005 because the
amendments allegedly introduce new matter into the disclosure (Answer 3).
Appellant asks us to review the Examiner’s objection to the amendment (Br.
12-14). However, this is a petitionable, rather than appealable, matter, and
we express no opinion as to its propriety. See 37 C.F.R. § 1.181.

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Application 10/631,841

a coupling ratio between a capacitance value of said large
capacitor and a capacitance value of a parasitic capacitor
coupled between said bias node and a ground reference point is
approximately equal to a unity value such that a biasing voltage
at said biasing node follows said lower supply voltage to
minimize effects of a ground noise signal between the lower
supply voltage and the ground reference point.

(Independent claims 1, 12, 23, and 33).

The Appellant disagrees. Appellant contends that the concept of a
coupling ratio is not new in the art. Appellant asserts that the coupling ratio
of the instant invention approaches a maximum value of unity (1) as the
magnitude of the capacitance of the large capacitor (CHC) increases relative
to the capacitance of the parasitic capacitor (Cp). Thus, Appellant contends
that an artisan would clearly recognize a large coupling value as any value
that approached unity (1) (Br. 16).
The Examiner agrees with Appellant that the coupling ratio is easily
derived as CR = CHC/(CHC + CP) (Answer 8, ¶3). The Examiner further
agrees that “it is clear that if the large capacitor CHC is much larger than the
parasitic capacitor Cp then the coupling ratio CR will [approach] 1.” (Id.)
Nevertheless, the Examiner finds the original Specification (including the
claims) failed to describe the coupling ratio of CR = CHC/(CHC + CP) as
approximately a unity value (1), i.e., where the value of the large capacitor
CHC is much larger than the value of parasitic capacitor Cp, such that the
coupling ratio CR approaches one (Id.).

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Application 10/631,841

We begin our analysis by noting that the Court of Appeals for the
Federal Circuit has held that “[t]o fulfill the written description requirement,
the patent specification must describe an invention in sufficient detail that
one skilled in the art can clearly conclude that the inventor invented what is
claimed.” Cordis Corp. v. Medtronic AVE, Inc., 339 F.3d 1352, 1364 (Fed.
Cir. 2003) (citations omitted). Our reviewing court has cautioned, however,
that “[t]he disclosure as originally filed does not . . . have to provide in haec
verba support for the claimed subject matter at issue.” Id. at 1364.
“Although [the applicant] does not have to describe exactly the subject
matter claimed, . . . the description must clearly allow persons of ordinary
skill in the art to recognize that [he or she] invented what is claimed.” In re
Gosteli, 872 F.2d 1008, 1012 (Fed. Cir. 1989) (citations omitted). Put
another way, “the applicant must . . . convey with reasonable clarity to those
skilled in the art that, as of the filing date sought, he or she was in possession
of the invention.” Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 1563-64
(Fed. Cir. 1991) (emphasis in original). The written description, although it
need not include information that is already known and available to the
experienced public, must be in sufficient detail to satisfy the statutory
requirements, employing “[w]ords, structures, figures, diagrams, formulas,
etc., that fully set forth the claimed invention.” Space Systems/Loral, Inc. v.
Lockheed Martin Corp., 405 F.3d 985, 987 (Fed. Cir. 2005) (quoting
Lockwood v. American Airlines, Inc., 107 F.3d 1565, 1572 (Fed. Cir. 1997)).
Finally, “[p]recisely how close the original description must come to comply
with the description requirement of § 112 must be determined on a
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Application 10/631,841

case-by-case basis.” Eiselstein v. Frank, 52 F.3d 1035, 1039 (Fed. Cir.
1995) (citation omitted).
After carefully considering the evidence before us, we will reverse the
Examiner’s rejection of claims 1-42 as failing to comply with the written
description requirement for essentially the same reasons argued by Appellant
in the Brief. In particular, we note the Examiner has acknowledged that the
coupling ratio is easily derived as CR = CHC/(CHC + CP) (See Answer 8, ¶3).
The Examiner has further acknowledged that “it is clear that if the large
capacitor CHC is much larger than the parasitic capacitor Cp then the
coupling ratio CR will [approach] 1.” (Id.). We note that Appellant need not
include information in the disclosure that is already known and available to
the experienced public. See Space Systems/Loral, Inc. v. Lockheed Martin
Corp., 405 F.3d at 987. Therefore, we conclude that Appellant has provided
sufficient detail in the Specification to satisfy the statutory requirements and
convey with reasonable clarity to those skilled in the art that the inventors
were in possession of the invention at the time of filing.

35 U.S.C. § 112, second paragraph
We consider next the Examiner’s rejection of claims 1-42 as being
indefinite under 35 U.S.C. § 112, second paragraph, for failing to
particularly point out and distinctly claim the subject matter which Appellant
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regards as the invention. Specifically, the Examiner concludes that the
following claim language is misdescriptive of the disclosure2 (Answer 5):
a coupling ratio between a capacitance value of said large
capacitor and a capacitance value of a parasitic capacitor
coupled between said bias node and a ground reference point is
approximately equal to a unity value . . . ”

(independent claims 1, 12, 23, and 33).

In particular, the Examiner asserts that the coupling ratio, as claimed,
is merely determined by dividing the capacitance value of the large capacitor
by the smaller capacitance value of the parasitic capacitor. Thus, the
Examiner finds the claim language is misdescriptive of the Specification
(i.e., indefinite) because it appears to conform to a coupling ratio where CR
= CHC/CP instead of CR = CHC/(CHC + CP) (Answer 9).
The Appellant disagrees. Appellant rebuts the Examiner’s finding
with extrinsic evidence 3 that shows the coupling ratio is not the ratio of the
capacitance values between the very large capacitor and the parasitic
capacitor, as argued by the Examiner (See e.g., “Silicon Processing for the
VLSI Era,” page 625, formula ( 8 - 3)). As applied to the instant invention,

2 Although the terms of a claim may appear to be definite, inconsistency
with the specification disclosure or prior art teachings may make an
otherwise definite claim take on an unreasonable degree of uncertainty. In re
Cohn, 438 F.2d 989, 1000-01, 169 USPQ 95, 98 (CCPA 1971) (“No claim
may be read apart from and independent of the supporting disclosure on
which it is based.”).
3 See “Silicon Processing for the VLSI Era”, Volume II Process Integration,
Wolf, Latice Press, Sunset Beach, CA., 1990, pp: 623-627.
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Appellant contends that the coupling ratio represents the AC coupling of the
biasing voltage VB11 at the bias node b11 to the lower supply voltage VSS
(See Fig. 2).4 Appellant argues that this is essentially a capacitive voltage
divider and where the voltage VB11 at the bias node b11 becomes a function
of the coupling ratio (CR) expressed as CR = CHC/(CHC + CP) (Br. 17-18).
After carefully considering the evidence before us, we conclude that
Appellant’s claims 1-42 are not misdescriptive of the Specification. In
particular, we find that a broad but reasonable interpretation of the claim
language does not preclude a coupling ratio where CR = C /(C + CHC HC P).
Moreover, we find the Examiner’s interpretation here (i.e., that the claim
requires CR = C /CHC P) is inconsistent with the Examiner’s previous
admission that the coupling ratio is easily derived as CR = C /(C + CHC HC P)
(See Answer 8, ¶3). Therefore, we do not agree with the Examiner that the
claims are indefinite. Accordingly, we reverse the Examiner’s rejection of
claims 1-42 under 35 U.S.C. § 112, second paragraph.

35 U.S.C. § 103
Independent Claim 1
We consider next the Examiner’s rejection of independent claim 1 as
being unpatentable over AAPA in view of Rapp.

4 We note that Appellant refers to “bias node b11” in the Brief (Br. 17-18).
We find no “bias node b11” shown in Fig. 2. However, biasing node b11 is
described with respect to Fig. 2 in the Specification on page 62, lines 14, 15,
and 20. We consider this discrepancy as an apparent typographical error in
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In rejecting claims under 35 U.S.C. § 103, it is incumbent upon the
Examiner to establish a factual basis to support the legal conclusion of
obviousness. See In re Fine, 837 F.2d 1071, 1073 (Fed. Cir. 1988). In so
doing, the Examiner must make the factual determinations set forth in
Graham v. John Deere Co., 383 U.S. 1, 17 (1966). “[T]he examiner bears
the initial burden, on review of the prior art or on any other ground, of
presenting a prima facie case of unpatentability.” In re Oetiker, 977 F.2d
1443, 1445 (Fed. Cir. 1992). Furthermore, “‘there must be some articulated
reasoning with some rational underpinning to support the legal conclusion of
obviousness’ . . . [H]owever, the analysis need not seek out precise teachings
directed to the specific subject matter of the challenged claim, for a court
can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ.” KSR Int’l Co. v. Teleflex Inc., 127
S. Ct. 1727, 1741 (2007) (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir.
2006)). To be nonobvious, an improvement must be “more than the
predictable use of prior art elements according to their established
functions.” KSR, 127 S. Ct. at 1740.
Appellant has the burden on appeal to the Board to demonstrate error
in the Examiner’s position. See In re Kahn, 441 F.3d at 985-86 (“On appeal
to the Board, an applicant can overcome a rejection [under § 103] by
showing insufficient evidence of prima facie obviousness or by rebutting the
prima facie case with evidence of secondary indicia of nonobviousness.”)

Fig. 2, i.e., bias node “b1” of Fig. 2 should be labeled as bias node “b11.”
Appropriate correction should be made during further prosecution.
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(quoting In re Rouffet, 149 F.3d 1350, 1355 (Fed. Cir. 1998)). Therefore, we
look to Appellant’s Brief to show error in the proffered prima facie case.
Appellant points out that the capacitor in Rapp is connected to a
ground reference point, and thus does not charge couple the biasing node to
the lower supply voltage such that the voltage at the biasing node follows the
lower supply voltage (Br. 19-20). Appellant notes that the circuit of Rapp
provides a comparator circuit that compares the voltage value of a
programming voltage supply VPP at node A of Fig. 5 against the voltage
value of the power supply voltage VDD. Appellant notes that Rapp’s
capacitor helps “to hold the voltage constant at the gate of transistor 86” (See
Rapp, col. 9, ll. 41-42). In particular, Appellant argues that holding the
voltage constant at the transistor gate (as taught by Rapp) does not provide
the coupling of the lower supply voltage to the biasing node as required by
the claims of the instant invention (Br. 20). Appellant further contends that
the Examiner has failed to provide a sufficient basis to show that the
combination of AAPA with Rapp would have been obvious to one skilled in
the art (Id.).
The Examiner disagrees. The Examiner contends that Fig. 5 of Rapp
shows large capacitor (90) coupled between the bias node (i.e., the gate of
transistor 86) and a lower supply voltage of the Fig. 5 circuit, such that when
combined with the AAPA circuit (Fig. 1), then the capacitor 90 in Fig. 5 of
Rapp will be connected between the bias node (b1, Fig. 1 of AAPA) and the
lower supply voltage Vss of input buffer 100 (Figure 1 of AAPA), and thus
the capacitor (90) in the combination/modification will charge couple the
biasing node bl to the lower supply voltage Vss (Answer 10).
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After carefully considering all of the evidence before us, we cannot
affirm the Examiner on this record. We find there is nothing in the record
that indicates the recited “lower supply voltage” and “ground reference
point” have the same voltage potential (Claim 1). Indeed, as is conventional,
“ground” typically refers to a zero-volt reference point in a circuit. Because
the instant invention is directed to reducing or eliminating the adverse
biasing effects of “ground noise” (i.e., Vss noise), such noise clearly
represents a voltage potential between a ground reference point and a lower
supply voltage (Vss).5 In particular, we find the Examiner’s proffered
combination of AAPA and Rapp does not show a large capacitor coupled
between a bias node and a lower supply voltage (i.e., that is not ground).
AAPA has no large capacitor connected between b1 and Vss (Fig. 1). The
Examiner looks to Rapp for the missing capacitor. However, Rapp’s
transistor 90 (functioning as a capacitor)6 is clearly shown in Fig. 5 as being
connected between the gate (bias point) of transistor 86 and a ground
reference point.
Moreover, we find it highly unlikely that transistor 90 (functioning as
a capacitor, see Rapp, col. 9, ll. 40-41) would reasonably possess the level of
capacitance typically associated with a “large capacitor,” as claimed by the
instant invention. Indeed, while a parasitic capacitance is associated with a

5 See Specification, page 62, paragraph 0016: “The ground noise (VSS
noise), as described above, is developed between the lower supply voltage
VSS and the ground reference voltage.”
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Application 10/631,841

MOSFET device, (as represented by Cp in AAPA, Fig. 1), a first parasitic
capacitance (i.e., the parasitic capacitance associated with Rapp’s transistor
90) is not reasonably a “large capacitor” with respect to a second parasitic
capacitance (as represented by Cp in AAPA, Fig. 1). For us to affirm the
Examiner on this point would require speculation on our part.
Because the Examiner has failed to show each element connected or
coupled as recited in the independent claim 1, we need not reach the issue of
motivation to reverse the Examiner’s rejection of claim 1 as being
unpatentable over the teachings of AAPA in view of Rapp. We find
identical language (i.e., “a large capacitor coupled between the bias node
and a lower supply voltage”) recited in each of independent claims 12 and
23, and equivalent language recited in independent claim 33 (i.e., “a large
capacitor between the bias node and the lower supply voltage”). Therefore,
we reverse the Examiner’s rejection of independent claims 12, 23, and 33 as
being unpatentable over the teachings of AAPA in view of Rapp for the
same reasons discussed supra with respect to independent claim 1. Because
we have reversed the Examiner’s rejection of each independent claim on
appeal, we also reverse the Examiner’s rejection of dependent claims 2-11,
13-22, 24-32, and 34-42 as being unpatentable over the teachings of AAPA
in view of Rapp.

6 Rapp discloses at col. 9, lines 39-42: “The source and drain of transistor 90
are connected to ground. Transistor 90 serves as a capacitor, helping to hold
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Application 10/631,841

DECISION
Based on the findings of facts and analysis above, we conclude
Appellant has shown by preponderance of the evidence that the Examiner
erred in rejecting claims 1-42 under 35 U.S.C. § 112, first and second
paragraphs, and also under 35 U.S.C. § 103 for obviousness. Therefore, the
decision of the Examiner rejecting claims 1-42 is reversed.

REVERSED

tdl/gvw

Stephen B. Ackerman
28 Davis Avenue
Poughkeepsie, NY 12603

the voltage constant at the gate of transistor 86 [emphasis added].”
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