AH225
1W High Linearity InGaP HBT Amplifier
Reduced Bias Configurations Application Note
The AH225 can be configured to be operated with lower bias current by varying the Vpd resistor-R1 as highlighted on the
schematic below. Lowering the current has little effect on the gain, OIP3, and P1dB performance of the device, but will
slightly lower the ACLR performance of the device as shown below. It is expected that variation of the bias current for other
frequency applications will produce similar performance results. The data below represents data taken from the AH225-
S8PCB1960 with data taken at 1960 MHz.
R1 (ꢀ) Icq (mA) Gain (dB) Pdiss (W) P1dB (dBm) OIP3 (dBm)1 Pout (dBm)2
56.2
82
500
400
300
200
100
15.6
15.4
15.2
14.8
14
2.5
2
+30.9
+30.9
+30.9
+31.1
+31.4
+48.7
+48.7
+48.5
+43.5
+37.7
+21.4
+21.6
+21.4
+19.9
+15
120
200
403
1.5
1
0.5
Notes:
1. OIP3 is measured with two tones at output power of 19 dBm / tone separated by 1 MHz spacing.
2. ACLR Test set-up: 3GPP WCDMA, TM1+64 DPCH, +5 MHz offset, PAR = 10.2 dB at 0.01% Prob. Pout (Channel power) at -50 dBc
ACLR is shown in the table above.
OIP3 vs. Pout / Tone vs. Bias Current
ACLR vs. Pout vs. Bias Current
3GPPWCDMA,TM1+64DPCH,±5 MHz Offset,1960 MHz
P1dB vs. Current
1960 MHz, 1 MHz spacing
-30
-35
-40
-45
-50
-55
-60
55
50
45
40
35
30
33
32
31
30
29
28
T=+25°C
T=+25°C
T=+25°C
100mA
200mA
300mA
400mA
500mA
100mA
200mA
300mA
400mA
500mA
17
19
21
23
25
19
20
21
22
23
24
25
100
200
300
400
500
Pout (dBm)
Pout / Tone (dBm)
Current (mA)
Data Sheet: Rev F 05/17/12
© 2012 TriQuint Semiconductor, Inc.
Disclaimer: Subject to change without notice
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