The information provided herein is believed to be reliable at press time. Stanford Microdevices assumes no responsibility for inaccuracies or omissions. Stanford Microdevices assumes no

responsibility for the use of this information, and all such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or

licenses to any of the circuits described herein are implied or granted to any third party. Stanford Microdevices does not authorize or warrant any Stanford Microdevices product for use in

life-support devices and/or systems.

Copyright 2000 Stanford Microdevices, Inc. All worldwide rights reserved.

1

http://www.stanfordmicro.com

Phone: (800) SMI-MMIC

522 Almanor Ave., Sunnyvale, CA 94085

EAN-101535 Rev A

DESIGN APPLICATION NOTE --- AN022

SGA-9289 Amplifier Application Circuits

Abstract

Stanford Microdevices’ SGA-9289 is a high

performance SiGe amplifier designed for operation

from DC to 3500 MHz. The amplifier is manufactured

using the latest Silicon Germanium Heterostructure

Bipolar Transistor (SiGe HBT) process. The process

process makes the SGA-9289 a very cost-effective

solution for applications requiring high linearity at

moderate biasing levels. This application note

illustrates several application circuits for key frequency

bands in the 800-2500 MHz spectrum.

Introduction

The application circuits were designed to achieve the

maintaining flat gain and reasonable return losses.

Special consideration was given to insure amplifier

stability at low frequencies where the device exhibits

high gain. These designs were created to illustrate the

general performance capabilities of the device under

CW conditions. Users may wish to modify these

designs to achieve optimum performance under

specific input conditions and system requirements.

The circuits contain only surface mountable devices

and were designed with automated manufacturing

requirements in mind. All recommended components

are standard values available from multiple

manufacturers. The components specified in the bill of

materials (BOM) have known parasitics, which in some

cases are critical to the circuit’s performance.

Deviating from the recommended BOM may result in a

performance shift due to varying parasitics – primarily

in the inductors and capacitors.

Biasing Techniques

These SiGe HBT amplifiers exhibit a “soft” breakdown

that under large signal conditions the source and load

impedances presented to the device don’t result in

excessive collector currents near breakdown. Small

SGA-9289

Silicon Germanium HBT Amplifier

Product Features

• DC-3500 MHz Operation

• High Output IP3, +41.5 dBm Typical at 1.96 GHz

• 11.0 dB Gain Typical at 1.96 GHz

• 28.6 dBm P1dB Typical at 1.96 GHz

• Cost Effective

Applications

• Wireless Infrastructure Driver Amplifiers

• CATV Amplifiers

• Wireless Data, WLL Amplifiers

r

e

t

e

m

a

r

a

Pl

o

b

m

y

Se

u

l

a

Vt

i

n

U

t

n

e

r

r

u

C

e

s

a

BI

B

0

2A

m

t

n

e

r

r

u

C

r

o

t

c

e

ll

o

CI

C

0

0

4A

m

e

g

a

t

l

o

V

r

e

t

t

i

m

E

-

r

o

t

c

e

ll

o

CV

O

E

C

0

.

7V

e

g

a

t

l

o

V

e

s

a

B

-

r

o

t

c

e

ll

o

CV

O

B

C

8

1V

e

g

a

t

l

o

V

e

s

a

B

-

r

e

t

t

i

m

EV

O

B

E

8

.

4V

e

r

u

t

a

r

e

p

m

e

T

g

n

i

t

a

r

e

p

OT

P

O

5

8

+

o

t

0

4

-C

e

g

n

a

R

e

r

u

t

a

r

e

p

m

e

T

e

g

a

r

o

t

ST

r

o

t

s

0

5

1

+

o

t

0

4

-C

e

r

u

t

a

r

e

p

m

e

T

n

o

i

t

c

n

u

J

g

n

i

t

a

r

e

p

OT

J

0

5

1

+C

Absolute Maximum Ratings