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
has a V
BCEO
=8V and an f
T
=25 GHz. The SiGe HBT
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
optimum combination of P
1dB
and OIP
3
while
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
effect (V
BCEO
=7.5V minimum) which allows for large
signal operation at V
CE
=5V. The user should insure
that under large signal conditions the source and load
impedances presented to the device don’t result in
excessive collector currents near breakdown. Small
signal operation with V
CE
<7V is acceptable.
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
Absolute Maximum Ratings
Parameter
Base Current
Collector Current
Collector - Emitter Voltage
Collector - Base Voltage
Emitter - Base Voltage
Operating Temperature
Storage Temperature Range
Operating Junction Temperature
Symbol
I
B
I
C
V
C EO
V
C BO
V
EBO
T
OP
T
stor
T
J
Value
20
400
7.0
18
4.8
-40 to +85
-40 to +150
+150
Unit
mA
mA
V
V
V
C
C
C
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.
522 Almanor Ave., Sunnyvale, CA 94085
Phone: (800) SMI-MMIC
1
http://www.stanfordmicro.com
EAN-101535 Rev A
STANFORD [ STANFORD MICRODEVICES ]
