AH215
The Communications Edge
TM
Product Information
1 Watt, High Linearity InGaP HBT Amplifier
Application Note: Reduced Bias Configurations
The AH215 can be configured to be operated with lower bias current by varying the bias-adjust resistor – R1. The
recommended circuit configurations shown previously in this datasheet have the device operating in Class A operation.
Lowering the current has little effect on the gain, OIP3, and P1dB performance of the device, but will slightly lower the
ACLR/ACPR performance of the device as shown below. An example of the measured data below represents the AH215
measured and configured for 2.14 GHz applications. It is expected that variation of the bias current for other frequency
applications will produce similar performance results.
AH215-S8PCB2140 Performance Data
R1
(ohms)
51
68
100
130
180
Icq
(mA)
450
400
350
300
250
Pdiss
(W)
2.25
2.00
1.75
1.50
1.25
P1dB
(dBm)
+31.0
+30.9
+30.8
+30.6
+30.5
OIP3
(dBm)
+47.1
+46.4
+46.4
+45.5
+43.6
2.14GHz Gain vs. Output Power
11.5
11
2.14GHz OIP3 vs. Output Power per Tone
50
45
10
9.5
9
8.5
16
OIP3 (dBm)
Gain (dB)
10.5
Idq=450mA 'Class A'
Idq=400mA
Idq=350mA
Idq=300mA
Idq=250mA
40
Idq=450mA 'Class A'
Idq=400mA
35
Idq=350mA
Idq=300mA
Idq=250mA
30
18
20
22
24
26
28
30
32
10
12
14
16
18
20
22
24
Output Power (dBm)
W-CDMA ACLR vs. Output Channel Power
3GPP W-CDMA, Test Model 1 + 64 DPCH, ±5 MHz offset
Power Out per Tone (dBm)
CW PAE vs. Output Power
100
Idq=450mA 'Class A'
Idq=400mA
Idq=350mA
-35
Idq=450mA 'Class A'
-40
Idq=400mA
PAE (%)
Idq=350mA
ACLR (dBc)
-45
-50
-55
-60
-65
12
Idq=300mA
Idq=250mA
Idq=300mA
Idq=250mA
10
1
14
16
18
20
22
24
16
18
20
22
24
26
28
30
32
W-CDMA Channel Power Out (dBm)
CW Tone Power Out (dBm)
Specifications and information are subject to change without notice.
WJ Communications, Inc
•
Phone 1-800-WJ1-4401
•
FAX: 408-577-6621
•
e-mail: sales@wj.com
•
Web site: www.wj.com
Page 6 of 7 September 2005
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