Federal Circuit: we've had this conversation; ipse dixit declarations don't cut it

Updated: Aug 12

TQ Delta, LLC, Appellant


Cisco Systems, Inc., Dish Network LLC, Comcast Cable Communications,

LLC, Cox Communications, Inc., Time Warner Cable Enterprises LLC,

Verizon Services Corp., Arris Group, Inc., Appellees



Decided: November 22, 2019

Case Summary

As the Federal Circuit explained in its 2006 Dystar decision, whether a

patent claim is invalid as obvious under 35 U.S.C. § 103 is a question of law

based on several underlying factual determinations, including: (a) whether

an artisan of ordinary skill would have been motivated to combine two or

more prior art references to achieve the claimed invention; and (b) whether

that ordinary artisan would have had a reasonable expectation of

successfully creating the invention. The courts require a motivation to

combine references because “inventions in most, if not all, instances rely on

building blocks long since uncovered, and claimed discoveries almost of

necessity will be combinations of what, in some sense, is already known.”

KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 418-19 (2007).

In Inter Partes Review proceedings, the PTAB’s decisions on obviousness

are often based on expert testimony; and to be upheld on appeal, a Board

decision finding a patent claim invalid as obvious must be supported by

substantial evidence. In this IPR appeal, a split panel of the Federal Circuit

held that Board factfinding based on conclusory expert testimony is never

sufficient to support an obviousness determination on substantial evidence


The Court’s opinion begins by describing an earlier district court judgment

of invalidity; this judgment was based on expert testimony stating that two

prior art references “could have been” combined to arrive at a claimed

invention. The Federal Circuit reversed, because although the expert testified

that the prior art references could have been combined to create the claimed

invention, she provided no evidence that an artisan of ordinary skill would

have been motivated to do so; instead, her testimony improperly relied on

the patent’s teachings as a roadmap to combine disparate teachings in the

prior art.

In a separate case, a district court held certain claims invalid as obvious after

an expert testified that the problem addressed in the claims was known in the

art, and further testified (without any factual basis) that components of the

claims were “modular” and could be easily interchanged with similar

components that were disclosed in six different prior art references. In its

decision reversing the lower court’s ruling, the Federal Circuit noted that the

expert’s testimony was “fraught with hindsight bias,” that he “fail[ed] to

explain why a person of ordinary skill in the art would have combined

elements from specific references in the way the claimed invention does,”

and that “[k]nowledge of a problem and motivation to solve it are entirely

different from motivation to combine particular references.”

In TQ Delta v. Cisco (the subject of this case summary), TQ Delta’s

related patents (9,014,243 and 8,718,158) disclose improvements to

multicarrier radio transmitters—that is, radio transmitters that

simultaneously transmit information over multiple radio channels. The

patents explain that the amount of power transmitted over any single radio

carrier varies over time and depends on the data being transmitted; and if the

carriers transmit the same (or similar data) simultaneously, the total amount

of power required by all of the channels will occasionally be more than the

transmitter can handle without transmission errors. The patents solve this

problem by scrambling the phases of the various radio carriers to spread out

(in time) the power peaks of the various radio carriers; this reduces a

transmission characteristic called the peak to average power ratio (PAR).

In its arguments before the PTAB, Cisco said that a combination of two

prior art references (patents 6,144,696 to Shively and 6,625,219 Stopler)

rendered TQ Delta’s patent claims invalid as obvious. Shively is directed

generally to multicarrier radio systems, but it does not disclose techniques to

reduce a transmitter’s peak to average power ratio. Stopler includes a twosentence

discussion of phase scrambling, but it contains no disclosure of

PAR reduction or multicarrier transmission.

Cisco’s expert testified that an artisan of ordinary skill at the time of the

invention would have been motivated to apply the phase randomization

technique disclosed in the Stopler reference to reduce the peak to average

power ratio of the multicarrier radio system disclosed in Shively, and that

the combination would have been “a relatively simple and obvious solution.”

However, Cisco’s expert provided no factual support for any of this

testimony, and the Federal Circuit wasn’t buying it. As they put it,

“Untethered to any supporting evidence, much less any contemporaneous

evidence, [Cisco’s expert’s] ipse dixit declaration ‘fail[s] to provide any

meaningful explanation for why one of ordinary skill in the art would be

motivated to combine these references at the time of this invention.’ It also

‘fails to explain why a person of ordinary skill in the art would have

combined elements from specific references in the way the claimed

invention does.’” (Citations omitted).

The Federal Circuit concluded by saying that without this evidentiary

support, the statements of Cisco’s expert fail “to resist the temptation to read

into the prior art the teachings of the invention in issue” (citing the Supreme

Court’s 1966 Graham case), and that the only support for his assertions were

found in TQ Delta’s patents; in other words, Cisco’s expert used TQ Delta’s

patents as a roadmap to piece together the otherwise unrelated teachings of

Shively and Stopler. Therefore, the expert’s “conclusory statements and

unspecific expert testimony” were inadequate to support the Board’s

factfinding regarding motivation to combine, and the Federal Circuit

reversed the PTAB’s obviousness determination.

Judge Hughes dissented without opinion.

2019.11 TQ DELTA v Cisco case summary
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