Ex Parte Knoblinger et al

Patent Trial and Appeal Board

Dec 10, 2014

12543637 (P.T.A.B. Dec. 10, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE
THE PATENT TRIAL AND APPEAL BOARD
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Ex parte GERHARD KNOBLINGER,1, 2
Marc Tiebout, and Franz Kuttner
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Appeal 2013-009183
Application 12/543,637
Technology Center 2800
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Before JEFFREY T. SMITH, BEVERLY A. FRANKLIN, and
MARK NAGUMO, Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

DECISION ON APPEAL
Gerhard Knoblinger, Marc Tiebout, and Franz Kuttner (“Infineon”)
timely appeal under 35 U.S.C. § 134(a) from the final rejection3 of
claims 1-3, 5, 7–9, and 11, which are all of the pending claims. We have
jurisdiction under 35 U.S.C. § 6. We affirm.

1 The real party in interest is listed as Infineon Technologies AG
(“Infineon”). (Appeal Brief, filed 11 March 2013 (“Br.”), 3.)
2 The present appeal is decided concurrently with appeal 2013-001061 in
copending application 12/543,629, which was filed on the same date as this
application, and which appears to share a substantively identical disclosure.
3 Office action mailed 1 June 2012 (“Final Rejection”; cited as “FR”).
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OPINION
A. Introduction4
The subject matter on appeal relates to digital controlled oscillators
(“DCO”) having drain extended MOS (“DeMOS”) transistors as active
devices. Such DCOs are said to have significantly improved phase noise
compared to prior art DCOs. (Spec. 4 [0014].) An embodiment of the
invention is illustrated in Figure 3, reproduced infra.

{Fig. 3 is said to show a digital controlled oscillator circuit}
DCO 3005 comprises an LC tank circuit 302, a cross coupled pair
circuit 304, and bias circuit 306 (Spec. 7 [0022]), which produces a

4 Application 12/543,637, DeMOS DCO, filed 19 August 2009. We refer to
the “’637 Specification,” which we cite as “Spec.”
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differential oscillating signal produced between output terminals OUTn and
OUTp (id. at 7 [0023]).
LC tank circuit 302 is coupled to supply voltage Vdd, and comprises
inductors 308 and 310 and plural digital variable capacitors
(“varactors”) 312 and 314. (Id.) Cross-coupled circuit 304 comprises drain-
extended MOS transistors (“DeMOS”) 316 and 318, the gate of one being
coupled to the drain of the other via AC-coupling capacitors 320 and 322.
(Id. at 7–8 [0024].) AC-coupling capacitors 320 and 322 are said to help
prevent a high voltage that may be present on the respective drains of
DeMOS transistors 316 and 318 from affecting the gates of transistors 318
and 316, respectively. (Id. at 9 [0027].) The presence of the DeMOS
transistors is said to “allow for a greater voltage swing on the drain as
compared to the voltage swing on the gate,” which in turn is said to improve
significantly the phase noise characteristics of the output. (Id. at. 9 [0027].)
Claim 1 is representative of the dispositive issues and reads:
A circuit arrangement, comprising:
a digitally controlled oscillator (DCO) circuit having
at least one active device,
wherein the at least one active device is a drain
extended (DeMOS) MOS transistor;
an LC tank coupled to the DeMOS transistors,
the LC tank including a set of digital varactors; and
an individual DeMOS transistor coupled to
each digital varactor in the set of digital varactors,

5 Throughout this Opinion, for clarity, labels in Figures are presented in
bold font, regardless of their presentation in the original document.
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wherein each gate associated with the DeMOS transistors
has an AC coupling capacitor coupled thereto via a first
capacitor terminal, and
each of the AC coupling capacitors is further coupled to
at least one of the digital varactors via a second capacitor
terminal of a respective one of the AC coupling capacitors.
(Claims App., Br. 12; some indentation, paragraphing, and emphasis added.)
The Examiner maintains the following ground of rejection:6, 7
Claims 1–3, 5, 7–9, and 11 stand rejected under
35 U.S.C. § 103(a) in view of the combined teachings of Amano8
and Schneider.9
B. Discussion
Findings of fact throughout this Opinion are supported by a
preponderance of the evidence of record.
Initially, we find that Infineon presents arguments for the patentability
based on the requirement, common to both independent claims 1 and 8, that
the circuit comprise drain extended (DeMOS) MOS transistors. All claims
therefore stand or fall with claim 1.

6 Examiner’s Answer mailed 9 May 2013 (“Ans.”).
7 A provisional obviousness-type double-patenting rejection iv view of
copending application 12/543,629 has been withdrawn in view of the
terminal disclaimer filed with the Brief (Br. 5). (Ans. 3.)
8 Shinji Amano, Voltage control oscillator . . . , U.S. Patent Application
Publication 2007/0075798 A1 (2007).
9 Jens Schneider and Harald Gossner, Drain-extended field effect transistor,
U.S. Patent Application Publication 2009/0140335 A1 (4 June 2009), based
on an application filed 4 December 2007: now U.S. Patent No. 7,838,940,
assigned to Infineon Technologies AG.
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Briefly, the Examiner finds that Amano describes a voltage controlled
oscillator circuit within the scope of the appealed claims, but for the use of
DeMOS transistors as the cross-coupled transistor pair. In particular, the
Examiner’s finds that Amano describes an LC tank including a set of digital
varactors (4, 5), individual transistor couple to each digital varactor in the set
of varactors, and AC coupling capacitors coupled to the transistors and to at
least one digital varactor. (FR 4, ll. 1–7.) The Examiner finds that
Schneider describes DeMOS transistors as being resistant to electrostatic
discharge, and reasons that it would have been obvious to use DeMOS
transistors in place of the transistors described by Amano.
{Amano Figure 1 is reproduced below}

{Amano Figure 1 illustrates a VCO circuit}
VCO 1a comprises resonance circuit 2, which in turn comprises
inductors 3 and variable capacitors 4 and 5. (Amano 3 [0033]–[0035].)
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Transistors 9 amplify an oscillation signal that is generated by resonance
circuit 2. (Id. at [0040].) Capacitors 15 isolate bases 11 from DC voltage 12
at the collectors 10, while coupling the AC signal. (Id.) A bias voltage is
supplied to the base 11 from bias circuit 16. (Id.)
Infineon does not dispute the Examiner’s findings that all the
limitations required by claims 1 and 8, but for the DeMOS transistors, are
described by Amano. In particular, Infineon does not dispute the
Examiner’s findings regarding the disclosure by Amano of digital
capacitors. In Infineon’s view, however, Amano fails to suggest the use of
transistors other than NMOS and PMOS transistors. (Br., 7, last para.)
Moreover, Infineon argues, “Amano never once mentions a DCO.” (Id.)
Infineon argues further that the Examiner has failed to provide a convincing
line of reasoning why it would have been an obvious matter of design
choice, or why it would have been obvious to try using DeMOS transistors
in Amano’s circuit. (Id. at 8-9.)
These arguments are not persuasive of harmful error. In light of
Amano’s teachings, the circuit designer would have expected, reasonably,
that any type of transistor having appropriate characteristics would have
been suitable for use in the VCO described by Amano. Cf. In re O'Farrell,
853 F.2d 894, 904 (Fed. Cir. 1988) (“For obviousness under §103, all that is
required is a reasonable expectation of success.”). The substitution of an
equivalent functional component for another is a classic instance of an
obvious substitution. Infineon has not directed our attention to any credible
evidence of record that DeMOS transistors were recognized as having
characteristics that would have dissuaded the routineer from using them in
place of the more conventional transistors named by Amano.
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What Amano calls the circuit is of little moment, as the critical
question is whether a person having ordinary skill in the art would have
understood Amano to disclose a circuit within the scope of appealed claim 1.
In the present case, Infineon has not disputed the Examiner’s findings
regarding Amano’s disclosure of digital capacitors. Nor has Infineon
disputed the Examiner’s findings that the components are connected in the
same way as required by the claims. Moreover, Infineon has not directed
our attention to a definition of the term “digital controlled oscillator” in
the ʼ637 Specification or in the extrinsic evidence of record that would
exclude Amano’s circuits as interpreted by the Examiner.10
Infineon’s arguments that the claims are patentable due to the
unexpected ability of the DeMOS transistors to provide a “greater voltage
swing on the drain [that] significantly improves phase noise” (id. at 9,
ll. 11-16) are not persuasive due to the lack of supporting evidence in the
record. The ʼ637 Specification lacks any working examples, and the Brief
and Reply are also devoid of examples and comparisons with the prior art.
In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984) (“[i]t is well settled that
unexpected results must be established by factual evidence. Mere argument
or conclusory statements in the specification does not suffice.”) In this
regard, we note that Amano discloses that phase noise is kept low by
keeping the VCO Kv gain low (Amano 4 [0046]). It is clear that there is
considerable complexity within the scope of the seemingly simple VCO

10 Infineon did not, for example, dispute the Examiner’s finding that, in
Amano Figure 1, the depiction of “switch 6 selectively controlling
capacitors 5 . . . makes the device (VCO of Amano) a DCO” (Ans. 4,
ll. 17-19). See the Reply Brief filed 9 July 2013 (“Reply”).
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circuits covered by the appealed claims. Thus, Infineon’s arguments for
unexpected results are also not reasonably commensurate with the scope of
exclusionary rights sought. In re Harris, 409 F.3d 1339, 1344 (Fed.
Cir. 2005) (evidence of secondary considerations must be “commensurate in
scope with the degree of protection sought by the claimed subject matter.”)
C. Order
We affirm the rejection of claims 1–3, 5, 7–9, and 11.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED

cdc