8.5-11.0 GHz GaAs Power Amplifier
Flange, 10 pin
August 2007 - Rev 21-Aug-07
P1006-FA
App Note [1] Biasing - This device is biased with Vd(1,2,3) = 8.0V and 4.0 A (pin 6,10). The drain current is controlled by the gate bias
with a typical value of Vg = -0.6V (pin 1). It is recommended to use active biasing to keep the currents constant as the RF power and
temperature vary; this gives the most reproducible results. The recommended power-up sequence is described below:
1. Apply -2.0 V to Vg
2. Apply +8.0 V to Vd(1,2,3)
3. Adjust Vg to achieve nominal drain current
4. Apply RF power
5. Re-adjust Vg to maintain nominal drain current.
Depending on the supply voltage available and the power dissipation constraints, the bias circuit may be a single transistor or a low
power operational amplifier, with a low value resistor in series with the drain supply used to sense the current. The gate of the pHEMT
is controlled to maintain correct drain current and thus drain voltage.
MTTF
MTTF is calculated from accelerated life-time data of single devices and assumes an isothermal back-plate.
XP1006-FA, MTTF with RF Power Applied
1.0E+06
100% DC duty cycle
1.0E+05
50% DC duty cycle
1.0E+04
30% DC duty cycle
1.0E+03
10% DC duty cycle
1.0E+02
1.0E+01
1.0E+00
1.0E-01
20
30
40
50
60
70
80
90
100 110 120
Backplate Temperature (C)
XP1006-FA, MTTF without RF Power
1.0E+05
1.0E+04
1.0E+03
1.0E+02
1.0E+01
1.0E+00
1.0E-01
1.0E-02
100% DC duty cycle
50% DC duty cycle
30% DC duty cycle
10% DC duty cycle
20
30
40
50
60
70
80
90
100 110 120
Backplate Temperature (C)
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Characteristic Data and Specifications are subject to change without notice. ©2007 Mimix Broadband, Inc.