Broadcom Corp. v. International Trade Commission

United States Court of Appeals for the Federal Circuit
2007-1164

BROADCOM CORPORATION,

Appellant,

v.

INTERNATIONAL TRADE COMMISSION,

Appellee,

and

QUALCOMM INCORPORATED,

Intervenor.

Robert A. Van Nest, Keker & Van Nest, LLP, of San Francisco, California, argued
for appellant. With him on the brief were Ragesh K. Tangri, Daniel E. Purcell, and
Steven K. Taylor. Of counsel were James M. Dowd, Gregory H. Lantier, and William G.
McElwain, Wilmer Cutler Pickering Hale & Dorr, LLP, of Washington, DC.

Michael Liberman, Attorney, Office of the General Counsel, United States
International Trade Commission, of Washington, DC, argued for appellee. With him on
the brief were James M. Lyons, General Counsel, Andrea C. Casson, Assistant General
Counsel for Litigation, and Clint A. Gerdine, Attorney. Of counsel were Paul Bartkowski,
David B. Fishberg, and James A. Worth, Attorneys.

Stephen B. Kinnaird, Sidley Austin LLP, of Washington, DC, argued for
intervenor. With him on the brief were Carter G. Phillips, Chantel L. Febus, and Robert
A. Parker. Of counsel on the brief were William K. West, Jr., Cecilia H. Gonzalez, and
Juliana M. Cofrancesco, Howrey LLP, of Washington, DC; Karin J. Kramer, Howrey
LLP, of San Francisco, California; Timothy S. Teter and Lori R.E. Ploeger, Cooley
Godward Kronish LLP, of Palo Alto, California; and Stanley J. Panikowski, DLA Piper
US LLP, of San Diego, California.

Appealed from: United States International Trade Commission
 United States Court of Appeals for the Federal Circuit

2007-1164

BROADCOM CORPORATION,

Appellant,

v.

INTERNATIONAL TRADE COMMISSION,

Appellee,

and

QUALCOMM INCORPORATED,

Intervenor.

On appeal from the United States International Trade Commission in
Investigation No. 337-TA-543.

___________________________

DECIDED: September 19, 2008
___________________________

Before RADER, BRYSON, and LINN, Circuit Judges.

BRYSON, Circuit Judge.

This appeal arises out of an investigation by the International Trade Commission

under section 337 of the Tariff Act of 1930, 19 U.S.C. § 1337. Broadcom Corporation

filed a petition with the Commission alleging that Qualcomm Incorporated had imported

chipsets that infringed five of Broadcom’s patents in violation of section 337: U.S.

Patent No. 5,682,379 (the ’379 patent), U.S. Patent No. 6,359,872 (the ’872 patent),
U.S. Patent No. 6,374,311 (the ’311 patent), U.S. Patent No. 6,583,675 (the ’675

patent), and U.S. Patent No. 6,714,983 (the ’983 patent). The administrative law judge

dismissed the claims that were based on the ’379 and ’872 patents after the United

States District Court for the Southern District of California ruled that a forum selection

clause required those patents to be litigated in California.

Following a hearing, the administrative law judge found that Qualcomm had

violated section 337 by inducing infringement of the ’983 patent. Based on that

determination, the Commission ultimately issued an exclusion order barring the

importation of devices containing Qualcomm’s baseband processor chips. After the

President declined review, Qualcomm and a number of handset device manufacturers

and service providers appealed the Commission’s order. Those appeals were

consolidated in Kyocera Wireless Corp. v. International Trade Commission, Nos. 2007-

1493 et seq., which is now pending before this court.

With respect to the ’311 and ’675 patents, however, the administrative law judge

found no violation of section 337, ruling that Qualcomm’s chipsets did not infringe the

claims of those two patents. After the Commission adopted the administrative law

judge’s noninfringement determinations, Broadcom filed this appeal. We affirm the

Commission’s noninfringement determination as to the ’311 patent, but we vacate the

noninfringement determination as to the ’675 patent in part, and we remand for further

proceedings.

I

As a preliminary matter, we address a jurisdictional argument raised by

Qualcomm. Qualcomm asserts that Broadcom’s petition for review was untimely

2007-1164 2
because Broadcom filed its petition for review once the Commission issued its

December 2006 order adopting the administrative law judge’s findings of

noninfringement. In Qualcomm’s view, the Commission’s order did not become final

and appealable until after the President declined review of the Commission’s exclusion

order based on the ’983 patent.

Qualcomm’s argument lacks merit in light of our decision in Allied Corp. v. United

States International Trade Commission, 782 F.2d 982 (Fed. Cir. 1986). In Allied, the

Commission found one of three asserted patents to be valid and infringed. For the

other two patents, the respondent succeeded in proving invalidity as a defense to

infringement. The Commission adopted the invalidity determinations on July 6, 1984,

and Allied sought to appeal those determinations to this court. Allied did not file its

petition for review until February 13, 1985, however. We dismissed Allied’s petition as

untimely because it was filed more than 60 days after the Commission adopted the

invalidity determinations. The Commission’s adoption of the invalidity determinations

was final, we held, because there was “no provision for Presidential review, or for other

administrative proceedings, following a determination that does not lead to an exclusion

order.” Id. at 984. In this case, similarly, once the Commission adopted the

administrative law judge’s noninfringement determination, there was no further

opportunity for review of that decision other than by way of review in this court.

Broadcom therefore did not prematurely file its petition for review once the Commission

issued its order.

Qualcomm makes the additional argument that this court lacks jurisdiction to

hear Broadcom’s appeal with respect to the ’311 patent. Qualcomm asserts that even if

2007-1164 3
Broadcom were to succeed in its appeal, the Commission would nevertheless lack

statutory authority to provide relief because the ’311 patent claims a network while

Qualcomm merely imports a component of the network. Qualcomm therefore argues

that any decision of this court with respect to the ’311 patent would be merely advisory.

We believe Qualcomm’s argument is better viewed as an alternative argument in

support of the Commission’s determination that Qualcomm did not violate section 337

by importing an article that infringes the ’311 patent. This court has jurisdiction to

review decisions of the Commission as to whether particular conduct violates section

337, see 19 U.S.C. § 1337(c), and thus we would have jurisdiction to review a ruling

that Qualcomm’s conduct did not violate section 337 despite infringing the ’311 patent.

In any event, however, the Commission based its decision that no section 337 violation

occurred on its determination that Qualcomm did not infringe the ’311 patent, a

determination that we plainly have jurisdiction to review.

II

A

The ’311 patent covers a communication network. One aspect of the disclosed

network is the ability for terminal nodes (e.g., handsets) and network access points to

synchronize their operation in order to allow the terminal nodes to operate in a power-

saving state. See ’311 patent, col. 15, ll. 44-54. According to the written description, a

terminal node may enter a “Sleep State” in which it can power down. Id. If a terminal

node is “Sleeping,” the network access point will temporarily store messages addressed

to the Sleeping node for delivery at a later time. Id. At synchronized intervals, the

network access point will transmit a “Hello” message, and Sleeping terminal nodes will

2007-1164 4
wake up in order to receive the transmission. Id. Any messages that have been stored

by the network access point will be transmitted to the terminal node after the Hello

message is sent. Id.

Broadcom asserted infringement of claims 1 and 16 and their dependent claims.

Claim 1 of the ’311 patent recites:

A communication network supporting wireless communication of
messages, said communication network comprising:

a first terminal node having a wireless receiver operable in a normal state;

a second terminal node having a wireless receiver operable in a power-
saving state;

an access point that attempts to immediately deliver messages destined
for the first terminal node;

the access point attempts to deliver messages destined for the second
terminal node by transmitting at predetermined intervals beacons that
identify that a message awaits delivery;

the second terminal node synchronizes operation of its wireless receiver
to receive the beacons from the access point; and

the second terminal node determines from the received beacons that it
has a message awaiting delivery and directs further operation of its
wireless receiver to receive the message.

Claim 16 of the ’311 patent similarly recites:

A communication network supporting wireless communication of
messages, said communication network comprising:

a first terminal node operating in a first state;

a second terminal node operating in a second state in which attempts are
made to minimize power consumption by the wireless receiver[;]

a bridging node having a wireless transceiver to support wireless
communication to the first and second terminal nodes;

the bridging node attempts to deliver messages destined for the second
terminal node by transmitting at predetermined intervals beacons that
identify a message awaiting delivery;

2007-1164 5
 the second terminal node synchronizing operation of its wireless receiver
to receive the beacons from the bridging node and determining from
the received beacons that it has a message awaiting delivery and
responding to an awaiting message by directing further operation of its
wireless receiver to receive the message; and

the bridging node delivering messages to the first terminal node without
requiring the first terminal node to determine from the beacons that it
has messages awaiting delivery.

Broadcom’s theory of infringement was that Qualcomm manufactures chipsets

that are used in wireless handsets on third-generation wireless networks that use a

wireless communication standard developed and promoted by Qualcomm (“the EV-DO

standard”). The EV-DO standard ensures compatibility between terminals (e.g.,

handsets) and networks by defining a series of “Connection Layer Protocols.” The

protocols pertinent to this case are the “Connected State Protocol” and the “Idle State

Protocol.” The Connected State Protocol describes the interaction of the network with a

terminal while the terminal is in active use, such as when the terminal is sending or

receiving a voice or data transmission. The Idle State Protocol describes the interaction

of the network with a terminal after a period of inactivity. In the Idle State Protocol, the

network and terminal may cycle through two states: a “Monitor State” in which the

terminal monitors a “Control Channel,” and a “Sleep State,” which the terminal may

enter if it detects no messages on the Control Channel.

According to Broadcom, EV-DO compliant networks necessarily infringe claims 1

and 16 of the ’311 patent because the EV-DO standard’s Idle State Protocol requires

networks to implement power-saving features. Broadcom therefore asserted direct

infringement based on Qualcomm’s use of its chipsets in handsets on its own test

network in the United States. Broadcom also argued that Qualcomm induced

infringement of the asserted claims based on Qualcomm’s promotion of the EV-DO

2007-1164 6
standard. The administrative law judge rejected Broadcom’s assertion of direct

infringement, finding that Broadcom’s evidence was insufficient to prove that

Qualcomm’s handsets operated in a “power-saving state” at any point during the testing

process. With respect to Broadcom’s claim of induced infringement, the administrative

law judge agreed with Broadcom that third-party EV-DO networks directly infringed

claim 1. The administrative law judge nevertheless rejected Broadcom’s theory of

induced infringement, finding that the EV-DO standard does not require handsets used

on EV-DO compliant networks to operate in a power-saving state. The administrative

law judge therefore found that Qualcomm lacked the requisite level of intent to induce

infringement of the claims of the ’311 patent.

B

Broadcom’s primary argument on appeal is that EV-DO compliant networks

necessarily infringe the claims of the ’311 patent and therefore the administrative law

judge’s conclusions with respect to direct and induced infringement are both incorrect.

Broadcom asserts that under the EV-DO standard, networks must implement the Idle

State Protocol’s Sleep State and that the Sleep State involves powering down a

handset’s wireless receiver. Qualcomm and the Commission respond that handsets

implementing the Sleep State are not required to power down their wireless receivers

while in the Sleep State. Qualcomm further argues that the EV-DO standard does not

require handsets even to enter the Sleep State because the standard allows for

handsets to operate in a “continuous operation” mode in which the handset continuously

monitors the channel from which it receives messages.

2007-1164 7
 The administrative law judge relied on the first argument pressed by Qualcomm

and the Commission, and we affirm on that basis. The EV-DO standard provides that a

terminal in the Sleep State “may shut down part of its subsystems to conserve power”

and that the terminal “may shut down processing resources to reduce power

consumption.” The EV-DO specification makes clear that the use of the word “may”

instead of “shall” indicates that a certain feature is not required by the standard.

According to the EV-DO specification,

“Shall” and “shall not” identify requirements to be followed strictly to
conform to the standard and from which no deviation is permitted. . . .
“May” and “need not” indicate a course of action permissible within the
limits of the standard.

Based on the language of the EV-DO specification, Mr. Grob, one of Qualcomm’s

experts, testified that handsets are not required to conserve battery power in the Sleep

State and that whether a handset powers down the wireless receiver depends on

whether the handset’s vendor decides to implement that feature. In response to that

testimony, Broadcom relies only on general testimony regarding the operation of

handsets under the EV-DO standard. Although portions of the testimony Broadcom

cites include statements that handsets power down their wireless receivers in the Sleep

State, Broadcom cites no evidence to suggest that terminals must do so in order to be

compatible with EV-DO networks.

Moreover, we agree with Qualcomm that the EV-DO standard does not require

handsets to implement the Sleep State. Broadcom cites four passages from the EV-DO

specification to support its contention that the Sleep State is a mandatory feature.

Those passages, however, do not support Broadcom’s position. The first three

passages on which Broadcom relies describe the requirements of the network, not the

2007-1164 8
handsets. For instance, the EV-DO specification states that the “[a]ccess network shall

transition from the Sleep State if the access terminal did not advertise a suspend period

that is current.” The corresponding requirement for handsets operating on the network

provides that the “access terminal may transition to the Sleep State if . . . [the] [a]ccess

terminal has not advertised a suspend period that is current.” And although the fourth

passage on which Broadcom relies actually describes the requirements for handsets,

that passage does not support Broadcom’s position because it describes requirements

for handsets that have entered the Sleep State, stating that “the access terminal shall

transition from the Sleep State to the Monitor State in time to send and receive,

respectively, the synchronous capsule.” Qualcomm, on the other hand, points out that

the EV-DO specification explicitly provides that handsets do not need to enter the Sleep

State, where the specification states that an access terminal may operate in a

continuous operation mode “in which the access terminal continuously monitors the

Control Channel.”

Even though the EV-DO standard does not require handsets to operate in a

power-saving state, Broadcom also argues that the administrative law judge should

have nevertheless made a finding of intent to induce infringement based on

Qualcomm’s promotion of the EV-DO standard’s optional features. The Commission

and Qualcomm, however, assert that Broadcom never presented that argument to the

administrative law judge. In response, Broadcom does not point to anything in the

record to show that it made that inducement argument to the administrative law judge.

Broadcom therefore may not rely on that argument on appeal.

2007-1164 9
 C

Broadcom also argues that the administrative law judge erred by not directly

addressing infringement of claim 16. That argument is without merit. When addressing

Broadcom’s assertion of direct infringement, the administrative law judge explicitly

stated that Broadcom failed to introduce “evidence that Qualcomm’s test networks

contain . . . ‘a second terminal node operating in a second state in which attempts are

made to minimize power consumption by the wireless receiver,’ as recited in

independent claim 16.” With regard to Broadcom’s claim of induced infringement, the

administrative law judge found that Broadcom provided “insufficient proof to show that

Qualcomm intended to induce infringement of the particular asserted claims.”

Broadcom challenges that conclusion with respect to claim 16 by arguing that, even if

EV-DO compliant networks do not necessarily infringe claim 1, they nevertheless must

infringe claim 16. Broadcom argues that, even if handsets are not required to power

down their wireless receivers in the Sleep State, they will nevertheless “minimize power

consumption by the wireless receiver” simply by not being in the Monitor State. As

noted earlier, however, handsets are not required by the EV-DO standard to enter the

Sleep State, but instead may operate in a continuous operation mode in which they

remain continuously in the Monitor State. In any event, Broadcom waived its argument

regarding claim 16 by not raising it before the Commission in its petition for review of

the administrative law judge’s decision. See Finnigan Corp. v. Int’l Trade Comm’n, 180

F.3d 1354, 1362 (Fed. Cir. 1999) (“A party seeking review in this court of a

determination by the Commission must ‘specifically assert’ the error made by the ALJ in

its petition for review to the Commission.”).

2007-1164 10
 D

Finally, Broadcom asserts that the administrative law judge erred by requiring

Broadcom to prove actual use of a handset in a power-saving state, rather than only

requiring Broadcom to show that Qualcomm used handsets containing chipsets capable

of being used in a power-saving state. The Commission and Qualcomm respond that

Broadcom waived that argument. The Commission asserts that Broadcom waived the

argument by not raising it before the administrative law judge, while Qualcomm asserts

that Broadcom waived the argument by failing to raise the argument in its petition for

review to the Commission. As to the merits, the Commission and Qualcomm present

different arguments. The Commission argues that the administrative law judge did not

in fact require Broadcom to show that Qualcomm actually used its handsets in a power-

saving state. Qualcomm, however, argues that proof of infringement of the asserted

claims requires proof of actual operation of a handset in a power-saving state.

First, we agree with Broadcom that the administrative law judge required proof

that Qualcomm’s handsets were actually operated in a power-saving state, but we

agree with the Commission that Broadcom failed to raise that issue before the

administrative law judge. Qualcomm and Broadcom presented to the administrative law

judge different constructions of the claim term “a second terminal node having a

wireless receiver operable in a power-saving state.” Qualcomm argued that, to meet

that claim limitation, the second terminal node must always operate in the power-saving

state—i.e., that the power-saving state must be an immutable mode of operation.

Broadcom argued that the claim “requires only that the ‘wireless receiver’ must be

capable of being turned off.” The Commission’s staff sided with Broadcom, asserting

2007-1164 11
that “the claim only requires that at a given time there are at least two terminals—one

with its receiver powered up and one with its receiver in the power-saving state.”

Broadcom quoted that passage in its post-trial reply brief and stated that the staff had

“correctly articulated” the requirement for proof of the “second terminal node” limitation.

The administrative law judge therefore held that “a second terminal node having a

wireless receiver operable in a power-saving state” required that “at some point in time,

the second terminal node [is] in a ‘power-saving’ state.” Based on Broadcom’s

statement in its post-trial reply brief, we conclude that Broadcom did not adequately

present to the administrative law judge the argument it now presents on appeal—that no

proof of actual use was required. Broadcom has therefore waived that argument by

failing to preserve it in the proceedings before the administrative law judge. See Corus

Staal BV v. United States, 502 F.3d 1370, 1378 n.4 (Fed. Cir. 2007); Hazani v. Int’l

Trade Comm’n, 126 F.3d 1473, 1476-77 (Fed. Cir. 1997).

Second, we agree with Qualcomm that Broadcom waived its argument by not

raising it before the Commission in its petition for review. In response to Qualcomm’s

argument, Broadcom cites two passages from its petition for review. The first passage

is a general description of the patents involved in the investigation. The second

passage relates to an argument that it is not the “terminal node” but the “wireless

receiver” that must be operable in a “power-saving state.” Broadcom also relies on a

third passage that does not appear in its petition for review, but rather appears in its

response to Qualcomm’s petition for review. A review of those passages, however,

shows that Broadcom did not specifically assert, in its petition for review, the claim of

2007-1164 12
error that it now seeks to raise in this court. Broadcom’s argument is therefore barred

by the failure to raise it before the Commission. See Finnigan, 180 F.3d at 1362.

Qualcomm raises two additional grounds for affirming the Commission’s

determination: that the administrative law judge should have adopted its claim

construction of “beacons” as used in claims 1 and 16, and that the ’311 patent is invalid.

We do not address those arguments because we affirm the Commission’s

determination on the basis of the administrative law judge’s noninfringement findings.

See Solomon Techs. v. Int’l Trade Comm’n, 524 F.3d 1310, 1319-20 (Fed. Cir. 2008)

(“If we uphold the Commission’s order . . . we are not required to address every

possible ground on which the Commission’s order might be sustained.”).

III

A

We now turn to the Commission’s determination that there was no section 337

violation with respect to the ’675 patent. The ’675 patent relates to circuits for

transmitting and receiving radiofrequency (“RF”) signals. Devices that transmit or

receive RF signals process information from those signals at a much lower frequency

than the frequency of the RF signal itself. The lower frequency signal is commonly

known as a “baseband signal.” Transmitting an RF signal therefore requires converting

the baseband signal to a higher frequency. That step is performed by a mixer, or

modulator, which combines the baseband signal with an oscillator signal that is tuned to

the desired output frequency. ’675 patent, col. 1, ll. 13-15.

RF transmitters commonly use a circuit called a phase lock loop (“PLL”), pictured

below, to generate the oscillator signal. ’675 patent, col. 1, ll. 23-27.

2007-1164 13
A PLL is a feedback loop that uses a voltage controlled oscillator (“VCO”) to generate

the oscillator signal from an input reference signal. The VCO contains a circuit known

as an LC circuit that contains multiple fixed capacitors in parallel with an inductor and a

varactor diode (i.e., a variable capacitor). The LC circuit therefore has a resonant

frequency that depends on the capacitance of the fixed capacitors and on the

capacitance of the varactor diode. The resonant frequency—which sets the frequency

of the oscillator signal—can be tuned in two ways. Switching in or switching out the

fixed capacitors provides a means for coarse tuning the frequency, while varying the

voltage across the varactor diode provides a means for fine tuning the frequency. Id.,

col. 1, ll. 43-58.

For fine tuning the frequency of the oscillator signal, the voltage across the

varactor diode is adjusted by comparing the input reference signal to the oscillator

signal, which ideally has a frequency that is a multiple of the frequency of the input

reference signal. To compare the signals, the oscillator signal is passed through a

frequency divider. The frequency divided oscillator signal and the input reference signal

are both provided as inputs to a phase detector. If the two signals are in phase, no

adjustment to the voltage across the varactor diode is necessary. If the two signals are

out of phase, the phase detector sends an error signal to a charge pump, which

2007-1164 14
increases or decreases the voltage across the varactor diode in order to “shift” the

frequency of the oscillator signal. ’675 patent, col. 6, ll. 1-23.

In VCOs that use varactor diodes, adjusting the voltage across the varactor diode

to achieve the desired change in the frequency of the oscillator signal can be

problematic. That is because the “VCO gain” is not constant. VCO gain is defined as

the amount by which the frequency of the oscillator signal shifts divided by the change

in the voltage across the varactor diode. VCO gain is not constant because a given

voltage applied to the varactor diode will cause a different frequency shift in the

oscillator signal for each combination of fixed capacitors that is switched in to the LC

circuit. ’675 patent, col. 1, ll. 59-64.

To solve that problem, a “gain compensation circuit” can be added to a PLL. A

gain compensation circuit provides a “reference pump current” to the charge pump. The

magnitude of that current is calculated based on the particular set of fixed capacitors in

the LC circuit that is switched in. As a result, the charge pump adjusts the voltage it

applies across the varactor diode to compensate for the amount of VCO gain caused by

the fixed capacitor set that is switched in. ’675 patent, col. 2, ll. 11-34. As shown in

Figure 4 of the ’675 patent, an ideal gain compensation circuit cancels out the VCO gain

so that the overall gain is constant:

2007-1164 15
Line 402 represents the VCO gain, which varies with the capacitance of the LC circuit.

Line 404 indicates gain compensation resulting from reference pump current applied to

the charge pump by the gain compensation circuit. The result, indicated by line 406, is

effectively constant VCO gain. ’675 patent, col. 8, ll. 16-30.

The invention of the ’675 patent is a gain compensation circuit. The circuit

generates the reference pump current from groups of unit current sources. The unit

current sources are in parallel and generate current that is equal in magnitude to a

“reference scale current.” Each group of unit current sources corresponds to a fixed

capacitor in the VCO. If a certain fixed capacitor is switched in to the VCO during

operation of the PLL, the gain compensation circuit switches in the corresponding group

of unit current sources, and the reference charge pump current is generated by

summing together the currents from each unit current source. The result is that the

magnitude of the reference charge pump current depends on which fixed capacitors of

the VCO are switched in. ’675 patent, col. 2, ll. 38-56.

2007-1164 16
 The patent further discloses using a current scaler to set the reference scale

current in order to allow the PLL to be used in different operating environments. For

instance, it may be desirable to set the reference scale current to operate with different

input reference frequencies. ’675 patent, col. 9, ll. 16-22. The patent therefore

describes using a current scaler to set the reference scale current based on a “PLL

control signal,” a signal that represents certain PLL characteristics such as input

reference frequency, loop bandwidth, or a damping factor. Id., col. 9, ll. 16-18. One

embodiment of a current scaler disclosed in the patent uses “weighted” current sources

whose individual weights are based on the PLL control signal. The currents from the

weighted current sources are summed together to generate the reference scale current.

Id., col. 11, line 63, to col. 12, line 18.

Claim 33 of the ’675 patent recites:

A gain compensator circuit that determines a reference pump current for a
charge pump in a phase lock loop (PLL), comprising

a plurality of unit current sources that are arranged into at least one group,
said group responsive to a capacitor control signal and generating a
portion of the reference pump current when said group is activated,
wherein said capacitor control signal also controls a corresponding
fixed capacitor of a voltage controlled oscillator (VCO) in the PLL; and

a current mirror including one or more weighted current sources that
generate a reference scale current responsive to a PLL control signal,
the PLL control signal representative of one or more characteristics of
the PLL,

each of said unit current sources generating a unit current proportional to
said reference scale current, said unit currents summed together to
form the reference pump current.

Broadcom accused eight of Qualcomm’s chips of infringing claim 33 and claim

35, a dependent claim of claim 33. Five of the chips are transmitter chips, which

upconvert baseband signals to RF signals. The remaining three chips are transceiver

2007-1164 17
chips, which downconvert RF signals to baseband signals in addition to performing the

function of the transmitter chips. Each of the chips has a PLL that includes a gain

compensation circuit. The gain compensation circuits are divided into two planes, an

upper plane and a lower plane. Each plane is composed of transistors that form a

current mirror—a circuit that replicates an input current.

The lower plane in Qualcomm’s chips has a fixed current of 50 µA on the input

side of the current mirror. The output side of the current mirror contains a series of

groups of transistors in parallel that can replicate the 50 µA input current. The groups of

transistors on the output side of the current mirror are turned on or off by a “CT signal.”

The CT signal is the signal used by the PLL’s VCO for coarse frequency tuning. It

therefore indicates which capacitors in the VCO are switched in. In the gain

compensation circuit, the CT signal turns on each group of transistors that corresponds

to a capacitor that is switched in to the VCO. The transistors that are turned on

replicate the 50 µA current, while those that are turned off generate no current. It is

undisputed that the lower plane in Qualcomm’s chips satisfies the first limitation of claim

33. The transistors are “unit current sources,” and they are turned on or off by the CT

signal, which is a “capacitor control signal.”

The output of the lower plane is the sum of the currents generated by the

transistors that are turned on. That output current flows to the input of the gain

compensation circuit’s upper plane. Qualcomm’s chips have two different designs for

the upper plane. The RFT6150 chip has a current mirror in the upper plane in which the

sole input is the output from the lower plane. The output side of the current mirror has

groups of transistors in parallel that can replicate the input current from the lower plane.

2007-1164 18
The transistors are turned on or off by a REF signal. The output of the second mirror—

the reference pump current—is the sum of the currents of the transistors that are turned

on by the REF signal. As implemented by Qualcomm’s chips, the REF signal does not

change during operation. The chips’ designer, Mr. Dunworth, testified that he originally

intended for the REF value to be used as “the expected value of the course tuning

code” and that it “would change with the VCO frequency.” But instead, the REF value

“is always hard coded to one value which is fixed as a constant value in the binary

source code provided by Qualcomm and that users of that code [do] not have access

to.”

In the other seven accused chips, the current from the lower plane is used

differently. The current from the lower plane is divided among groups of transistors in

parallel. Four of the groups of transistors are turned on or off by the REF value. The

fifth group of transistors provides the input current to a current mirror. On the output

side of the current mirror, a set of transistors replicates the input current, generating the

reference pump current, which flows to the charge pump.

The administrative law judge found that none of Qualcomm’s chips infringe claim

33. For the RFT6150 chip, the administrative law judge found no infringement because

the REF value did not qualify as a “PLL control signal.” Based on the testimony of Dr.

Milor, one of Broadcom’s experts, that a “control signal” must be “changeable,” the

administrative law judge ruled that REF value was not a control signal because it is hard

coded so that “consumers cannot change [it].” For the remaining seven chips, the

administrative law judge found no infringement on the ground that the transistors in the

lower plane did not satisfy the “weighted current sources” limitation, because the

2007-1164 19
transistors act as a current divider rather than as current sources. Broadcom

challenges both of those conclusions.

B

Broadcom argues that the administrative law judge’s finding of noninfringement

for the RFT6150 chip was based on a misunderstanding of Dr. Milor’s testimony.

Broadcom asserts that, according to Dr. Milor’s testimony, a control signal is

“changeable” if it is implemented in software, even if the control signal has a hard coded

value. The Commission argues that the administrative law judge’s conclusion is correct

because the REF value is not “changeable” if users of the binary code distributed by

Qualcomm cannot change the coded REF value. Qualcomm supports the Commission,

arguing that the REF value would have to change during actual operation of the PLL in

order for the REF value to be a “PLL control signal.” We agree with Broadcom that Dr.

Milor’s testimony does not support the administrative law judge’s finding.

The administrative law judge’s construction of “PLL control signal” contained no

requirement that a customer be able to change the value of the control signal. Rather,

the administrative law judge construed “PLL control signal” to mean “a control signal

representative of some characteristic of the PLL.” When applying that definition to

Qualcomm’s RFT6150 chip, however, the administrative law judge began by analyzing

whether the REF value was a “control signal.” The administrative law judge then

adopted Dr. Milor’s statement that a control signal “has got to be changeable” as a

definition for the phrase “control signal.” The administrative law judge therefore found

that the REF value was not a control signal because it could not be changed by

Qualcomm’s customers and because Qualcomm did not intend for its customers to

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change the value. That conclusion, however, is not supported by Dr. Milor’s testimony.

In fact, Dr. Milor testified that the REF value is a “PLL control signal” because it has a

value in Qualcomm’s software that could be changed by Qualcomm’s programmers.

She stated that a control signal must be “changeable” to distinguish a signal that is

hardwired into a circuit from a signal that is coded by software. Nowhere does Dr.

Milor’s testimony indicate that, in her view, a control signal is “changeable” only if

Qualcomm’s customers can change its coded value. Dr. Milor’s view was that the REF

value is “changeable” because the value that is hard coded into Qualcomm’s software

can be changed by Qualcomm. Therefore, if the administrative law judge adopted Dr.

Milor’s definition of “control signal,” the opposite conclusion was warranted. The

testimony of Mr. Dunworth, relied on by the administrative law judge and by the

Commission and Qualcomm on appeal, does not change the result under Dr. Milor’s

definition. Mr. Dunworth’s testimony that the REF value is hard coded in software by

Qualcomm’s programmers simply confirms that the REF value could be changed by

Qualcomm.

Moreover, the written description of the patent does not suggest that users of a

device using a radiofrequency transmitter must be able to change control signals in the

PLL. Indeed, an example of the ’675 patent indicates why it would be useful to have a

hard coded value for a PLL control signal. If a designer had to adjust a PLL to work with

a reference signal having twice the frequency of the original reference signal, the

designer might need to replace the frequency divider. But if the reference scale current

is controlled by a PLL control signal, the designer could simply adjust the coded value

for the PLL control signal in order to divide the reference scale current by two. See ’675

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patent, col. 12, ll. 34-50. That example shows that using a PLL control signal to adjust

the reference scale current can provide a benefit to the designer of a PLL, even if the

value for the PLL control signal remains the same after the PLL’s final design is

completed.

In addition, we reject Qualcomm’s argument that the administrative law judge’s

noninfringement finding should be affirmed on the basis that a “PLL control signal” must

change during actual operation of the circuit. The administrative law judge never

construed the phrase in that manner; in any event, Qualcomm’s claim construction is

contrary to the most reasonable interpretation of the claims of the ’675 patent. Claim

37, which depends from claim 33, recites a gain compensator circuit in which the

reference pump current is “responsive to variations in said one or more characteristics

of the PLL.” Qualcomm’s argument that the PLL control signal must change during

operation to reflect changes in a characteristic of the PLL would make claim 37

redundant, a consequence that renders the argument suspect. See nCube Corp. v.

SeaChange Int’l, Inc., 436 F.3d 1317, 1321-22 (Fed. Cir. 2006).

Broadcom further argues that the record supports the conclusion that the REF

value is a PLL control signal, asserting that the REF value is “representative of some

characteristic of the PLL,” as the administrative law judge’s construction requires. The

administrative law judge, however, did not reach that question. We therefore remand

the case for the Commission to determine whether the REF value meets that limitation

and, if so, whether Qualcomm’s RFT6150 chip satisfies the other limitations of claim 33.

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 C

With respect to the remaining seven chips, we hold that the administrative law

judge’s noninfringement determination is supported by substantial evidence. Broadcom

first argues that the administrative law judge’s analysis of the “weighted current

sources” limitation was erroneous because he did not determine whether the individual

transistors were “weighted current sources,” but instead looked at the entire plane

containing the identified transistors. That argument is without merit. The administrative

law judge found that “the weight of the evidence indicates that, with respect to each

accused product except the RFT6150, the highlighted transistors . . . are not current

sources, and therefore, also cannot be ‘weighted current sources’ as required by the

claim.” Although the administrative law judge relied on Mr. Gutierrez’s testimony that

the upper plane “does not . . . control the magnitude of the current that flows through it,

and, therefore, it is not a current source, but rather a current splitter,” other portions of

Mr. Gutierrez’s testimony make clear that he viewed the individual transistors as

branches of a current divider and not as current sources.

Turning to whether the transistors in the upper plane could be considered

“current sources,” the administrative law judge identified two types of current sources

based on testimony from Dr. Milor: independent and dependent current sources.

Independent current sources produce a current of fixed magnitude. It is undisputed that

the transistors at issue are not independent current sources. Dependent current

sources, on the other hand, “generate[] a current as a function of another voltage or

current.” The magnitude of the currents passing through the upper plane transistors

depends on two factors: the REF value and the magnitude of the current flowing out of

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the lower plane. That is, the current flowing from the lower plane is divided into the

groups of transistors that are turned on by the REF value. Mr. Gutierrez therefore

testified that transistors in the upper plane “are not acting as current sources,” but

rather, they “are acting as the termination of the currents in the bottom.” Although Dr.

Milor testified that the transistors could be considered dependent current sources, she

agreed that the current flowing through those transistors would have no effect on the

current in the lower plane. That is, the transistors in the lower plane are the current

sources that determine the magnitude of the current flowing through the upper plane.

The administrative law judge therefore reasonably concluded that the individual

transistors do not generate current but instead act as branches of a current divider.

Accordingly, we affirm the finding of noninfringement of the ’675 patent with respect to

the seven chips other than the RFT6150 chip.

IV

In sum, we affirm the Commission’s determination that Qualcomm’s chipsets do

not infringe the ’311 patent. We vacate in part the Commission’s determination with

respect to the ’675 patent and remand for the Commission to determine whether the

REF value of RFT6150 circuit is “representative of some characteristic of the PLL” and

whether the RFT6150 meets the remaining limitations of claims 33 and 35 of the ’675

patent. With respect to the ’675 patent as applied to the remaining chips, we affirm the

Commission’s determination of noninfringement.

Each party shall bear its own costs for this appeal.

AFFIRMED IN PART, VACATED IN PART, and REMANDED.

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