Ex Parte Mohindra

Board of Patent Appeals and Interferences

Jan 31, 2003

08668114 (B.P.A.I. Jan. 31, 2003)

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The opinion in support of the decision being entered
today was not written for publication in a law journal
and is not binding precedent of the Board.
Paper No. 32
UNITED STATES PATENT AND TRADEMARK OFFICE

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

Ex parte RISHI MOHINDRA

Appeal No. 2001-2018
Application No. 08/668,114

ON BRIEF

Before THOMAS, KRASS, and JERRY SMITH, Administrative Patent
Judges.
KRASS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the final rejection of
claims 2 and 8-13.
The invention is directed to a quadrature demodulator.
Independent claim 12 is representative of the embodiment wherein
the quadrature demodulator has a phase shifting network that
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Application No. 08/668,114
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comprises a series arrangement of network elements. Independent
claim 13 is representative of the embodiment wherein the
quadrature demodulator has a phase shifting network that
comprises a parallel arrangement of network elements.
Independent claim 12 is reproduced as follows:
12. A quadrature demodulator for demodulating an
intermediate frequency signal obtained from an angle modulated
radio frequency signal, the quadrature demodulator having a first
branch, a phase shifting network in a quadrature branch, and a
multiplier means, said first branch and said phase shifting
network being coupled to said multiplier means, and wherein said
phase shifting network comprises a series arrangement of a first
resistor and a first capacitor, said series arrangement being
coupled to a first inductor, a junction of the series arrangement
and the first inductor being an output of the phase shifting
network providing a quadrature signal and wherein said junction
is directly connected to an input of said multiplier means,
whereby the first resistor provides a damping such that an
overall quality factor of the phase shifting network is
substantially smaller than a quality factor of the inductor.
The examiner relies on the following references:
Kimyacioglu 4,866,397 Sep. 12, 1989
Worsham, Jr. 5,414,385 May 09, 1995
Nilsson, “Electric Circuits”, Addison-Wesley Publishing
Company, Third Edition (May 1990), pp. 393-394.
Claims 2 and 8-13 stand rejected under 35 U.S.C. 103 as
unpatentable over Worsham in view of Kimyacioglu and Nilsson.
Reference is made to the briefs and answer for the
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Application No. 08/668,114
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respective positions of appellant and the examiner.
OPINION
At the outset, we note that, in accordance with appellant’s
grouping of claims, at page 4 of the principal brief, claims 2, 8
and 10 will stand or fall with claim 12 and claims 9 and 11 will
stand or fall with claim 13.
Taking claim 12, and comparing the elements thereof to
Figure 2 of Worsham, we note that the reference discloses a
demodulator 15 comprising first and second branches with a phase
shifting network 31 in one branch and the phase shifting network
coupled to a multiplier means 32. Worsham also discloses a
capacitor 30 and an inductor 33, wherein the junction of these
elements is connected as the output of the phase shifting network
for providing a quadrature signal to the multiplier.
In fact, Worsham appears to disclose the claimed subject
matter but for the disclosure of a resistor in series with the
capacitor 30 and wherein the resistor provides a damping such
that the overall quality factor of the phase shifting network is
substantially smaller than a quality factor of the inductor.
The examiner recognized this difference and applied
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Application No. 08/668,114
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Kimyacioglu for a teaching of a phase shifter 52 having an RLC
network, though Figure 2 of Kimyacioglu appears to us to depict
two series-connected inductors connected to a capacitor. The
examiner then applies Nilsson for its teaching of equivalent
circuits to somehow provide an incentive for modifying the phase
shifting network of Worsham by providing for a resistor in series
with capacitor 30.
The examiner has failed to provide a convincing rationale as
to what would have led the artisan to modify Worsham to provide
for the claimed subject matter. The examiner’s motivation for
combining the applied references appears to come from appellant’s
own disclosure. Such hindsight gleaned from an applicant’s own
disclosure cannot serve as a basis for combining references
within the meaning of 35 U.S.C. 103.
A review of the examiner’s rationale, as per equivalent
circuits, appears to be more of a mathematical rationale as to
how the instant claimed subject matter may be constructed rather
than a sufficient basis to provide the answer as to why the
artisan would have been led to the instant claimed subject matter
without appellant’s disclosure. In short, we agree with
appellant [bottom of page 9 of the principal brief] that the
examiner has not provided a sufficient basis for replacing the
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Application No. 08/668,114
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phase shift network of Worsham with the simple phase shifting
network of the clock recovery circuit of Kimyacioglu which has
been modified by applying a single network equivalence theorem of
Thevenin. Moreover, the examiner has offered nothing, other than
the fact that it could be done, that would have led the artisan
to interchange the positions of the capacitor and the inductor in
Kimyacioglu’s phase shifter 52, in order to arrive at the claimed
subject matter.
Other than being in a parallel arrangement, the subject
matter of claim 13 is similar to that of claim 12. The other
claims all have similar recitations regarding the relationship
between the resistor and capacitor in the phase shifting network
of a quadrature demodulator. Therefore, our rationale, supra,
applies to these claims.
Accordingly, since the examiner has not provided a prima
facie case of obviousness, we will not sustain the rejection of
claims 2 and 8-13 under 35 U.S.C. 103.
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The examiner’s decision is reversed.
REVERSED
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
)
)
ERROL A. KRASS ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
)
JERRY SMITH )
Administrative Patent Judge )
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Application No. 08/668,114
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