AP602
High Dynamic Range 4W 28V HBT Amplifier
Application Circuit PC Board Layout
Baseplate Configuration
PCB Material: 0.0147” Rogers Ultralam 2000, single layer, 1 oz Cu,
ε
r
= 2.45, Microstrip line details: width = .042”, spacing = .050”
Notes:
1. Please note that for reliable operation, the evaluation board will have to be mounted to a much larger
heat sink during operation and in laboratory environments to dissipate the power consumed by the
device. The use of a convection fan is also recommended in laboratory environments.
2. The area around the module underneath the PCB should not contain any soldermask in order to
maintain good RF grounding.
3. For proper and safe operation in the laboratory, the power-on sequencing is recommended.
Evaluation Board Bias Procedure
Following bias procedure is recommended to ensure proper functionality of AP602 in a laboratory environment. The sequencing is not
required in the final system application.
Bias.
Vcc
Vbias
Vpd
Voltage (V)
+28
+5
+5
Turn-on Sequence:
1.
2.
3.
4.
5.
1.
2.
3.
4.
Notes:
1.
2.
3.
Attach input and output loads onto the evaluation board.
Turn on power supply Vcc = +28V.
Turn on power supply Vbias = +5V. At this point, the only current drawn by the device is leakage current (< 25µA).
Turn on power supply Vpd = +5V. Power supply Vcc should now be drawing typical Icq = 80 mA.
Turn on RF power.
Turn off RF power.
Turn off power supply Vpd = +5V.
Turn off power supply Vbias = +5V.
Turn off power supply Vcc = +28V.
Icq can be adjusted with the resistor R2 from the Vpd (+5V) supply and the PIN_VPD (pin14) of the amplifier. Increasing R2
results in a lower Icq. Icq should not be increased above 160mA.
Vpd is used as a reference for the internal active bias circuitry. It can be used to turn on/off the amplifier. Ipd depends on the Icq
quiescent current setting. Ipd can be up to 4mA at a quiescent current setting of 160mA.
Vbias should be maintained fixed at +5V. Ibias will change based on RF input power level. It can be up to 4mA on the AP602.
Turn-off Sequence:
Ipd vs Icq
4
Ibias (mA)
Ibias vs Output Power
4
3
2
1
0
Ipd (mA)
3
2
1
0
0
40
80
120
160
200
Icq Setting (mA)
22
24
26
28
30
32
Output Average Power (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 3 of 11 May 2007 ver 1
WJCI [ WJ COMMUNICATION. INC. ]
