Specifications and information are subject to change without notice.

WJ Communications, Inc

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Page 6 of 9 June 2005

AH312 / ECP200G

2 Watt, High Linearity InGaP HBT Amplifier

Product Information

Application Note: Reduced Bias Configurations

The AH312 / ECP200 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 AH312 /

ECP200 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.

AH312-PCB2140 Performance Data

R1

(ohms)

Icq

(mA)

Pdiss

(W)

P1dB

(dBm)

OIP3

(dBm)

15

800

4.0

+33.3

+51.4

22

700

3.5

+33.3

+50.9

43

600

3.0

+33.1

+50.9

62

500

2.5

+33.0

+50.7

110

400

2.0

+32.9

+47.3

2.14GHz Gain vs. Output Power

8.2

8.6

9

9.4

9.8

10.2

18

20

22

24

26

28

30

32

34

Output Power (dBm)

Idq=800mA 'Class A'

Idq=700mA

Idq=600mA

Idq=500mA

Idq=400mA

2.14GHz OIP3 vs. Output Power per Tone

35

40

45

50

55

10

12

14

16

18

20

22

24

Power Out per Tone (dBm)

Idq=800mA 'Class A'

Idq=700mA

Idq=600mA

Idq=500mA

Idq=400mA

W-CDMA ACLR vs. Output Channel Power

3GPP W-CDMA, Test Model 1 + 64 DPCH, ±5 MHz offset

-65

-60

-55

-50

-45

-40

-35

14

16

18

20

22

24

26

W-CDMA Channel Power Out (dBm)

Idq=800mA 'Class A'

Idq=700mA

Idq=600mA

Idq=500mA

Idq=400mA

CW PAE vs. Output Power

1

10

100

18

20

22

24

26

28

30

32

CW Tone Power Out (dBm)

Idq=800mA 'Class A'

Idq=700mA

Idq=600mA

Idq=500mA

Idq=400mA