8.0-12.0/16.0-24.0 GHz GaAs MMIC

Active Doubler

Page 4 of 6

App Note [1] Biasing

and Id2=110mA. Separate biasing is recommended if the doubler is to be used at high levels of saturation, where gate rectification

will alter the effective gate control voltage. It is also recommended to use active biasing to keep the currents 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 voltages needed to do this are Vg1=-0.9V and Vg2=-0.3V. 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 -

For individual Stage Bias (Recommended for doubler applications) -- Each DC pad (Vd1, 2 and Vg1, 2) needs to have DC bypass

capacitance (~100-200 pf ) as close to the device as possible. Additional DC bypass capacitance (~0.01 uF) is also recommended.

MTTFTables (TBD)

Bias Conditions: Vd1=Vd2=3.5V, Id1=25 mA, Id2=110 mA

These numbers were calculated based on accelerated life test information and thermal model analysis received from the fabricating foundry.

Backplate

Temperat re

55 deg Celsius

75 deg Celsius

95 deg Celsius

Channel

Temperat re

deg Celsius

deg Celsius

deg Celsius

FITs

E+

E+

E+

MTTF Ho rs

E+

E+

E+

Rth

C/W

C/W

C/W

Mimix Broadband, Inc., 10795 Rockley Rd., Houston, Texas 77099

Tel: 281.988.4600 Fax: 281.988.4615 mimixbroadband.com

Characteristic Data and Specifications are subject to change without notice.

©2007 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.

January 2007 - Rev 17-Jan-07

X1005-BD