17.0-22.0 GHz GaAs MMIC
Power Amplifier
September 2005 - Rev 01-Sep-05
18MPA0567
App Note [1] Biasing
-
As shown in the Bias Arrangement, bias Vd3=5.0V with Id=450mA. It is also recommended to use active
biasing to keep the current constant as the RF power and temperature vary; this gives the most reproducible results. 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. The typical gate voltage needed to do this is -0.9V. Typically the
gate is protected with Silicon diodes to limit the applied voltage. Also, make sure to sequence the applied voltage to ensure negative
gate bias is available before applying the positive drain supply.
App Note [2] Bias Arrangement
-
Vd3 and Vg3 require DC bypass capacitance (~100-200 pF) as close to the device as possible. Additional DC bypass capacitance
(~0.01 uF) is also recommended.
These numbers were calculated based on accelerated life test information and thermal model analysis received from the fabricating foundry.
Backplate
Temperature
55 deg Celsius
75 deg Celsius
95 deg Celsius
Channel
Temperature
ºC
ºC
ºC
Rth
MTTF Hours
C/W
C/W
C/W
du
E+
E+
E+
Pr
Mimix Broadband, Inc., 10795 Rockley Rd., Houston, Texas 77099
Tel: 281.988.4600 Fax: 281.988.4615 mimixbroadband.com
e-
pr
o
Bias Conditions:
Vd1=5.0V, Id=450 mA
ct
FITs
E+
E+
E+
MTTF Tables
Characteristic Data and Specifications are subject to change without notice.
©2005
Mimix Broadband, Inc.
Export of this item may require appropriate export licensing from the U.S. Government. In purchasing these parts, U.S. Domestic customers accept
their obligation to be compliant with U.S. Export Laws.
io
n
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