Appeal No. 96-1203
Application 08/298,721
The form of claim 1 recites a complementary hetero-
junction amplifier in which the P-channel transistor and the
N-channel transistor have approximately equal transconductances
and approximately equal input impedances. It would seem that any
such amplifier having these equal transconductances and equal
input impedances would necessarily have gate widths and lengths
that satisfy the language of claim 1. A key feature, however, is
that the input impedances of the N-channel and the P-channel
transistors are approximately equal. As noted above, Redfern
only teaches equating transconductances in the P-channel and N-
channel transistors of an inverter.
The examiner’s assertion that the invention of claim 1
would have resulted from an obvious design choice of parameters
as suggested by Redfern simply is not supported by the evidence
on this record. We are not inclined to dispense with the
requirement that the examiner present factual support for
contested positions on inherency or design choice. Since there
is no suggestion that the input impedance between the N-channel
and P-channel transistors should be made approximately equal, we
do not sustain the rejection of representative claim 1. Since
all the claims stand or fall together, we do not sustain the
rejection of any of claims 1-12.
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