XP1043-QH_10 Datasheet, PDF (5/7 Pages) Mimix Broadband – 12.0-16.0 GHz Power Amplifier

12.0-16.0 GHz Power Amplifier
QFN, 4x4mm
February 2010 - Rev 13-Feb-10
P1043-QH
App Note [1] Biasing - As shown in the Pin Designations table, the device is operated under the nominal bias conditions of VD1,2,3 at 7.0V with
100, 200, 400mA respectively. The device can also be safely biased to a maximum of 9 V and 1.4 A to provide greater than 2 Watts of saturated RF
power. It is recommended to use active bias to keep the currents constant in order to maintain the best performance over temperature. Under
heavy RF saturation the device will tend to self bias and pull the desired 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. The typical
gate voltage needed to do this is -1.0V. Make sure to sequence the applied voltage to ensure negative gate bias is available before applying the
positive drain supply.
App Note [2] Board Layout - As shown in the board layout, it is recommended to provide 100pF decoupling caps as close to the bias pins as
possible, with additional 10µF decoupling caps.
App Note [3] Power Detector - As shown in the schematic below, the power detector is implemented by providing +5V bias and measuring the
difference in output voltage with standard op-amp in a differential mode configuration.
Bias Circuit
From Bias
Circuit
R
-5V
To Gate
The output impedance of the bias circuit’s gate output should be
small. When in saturation, the gates of the XP1043-QH can draw
several mA which may cause adverse affects in a gate circuit with
high output impedance. It is recommended that an Emitter
Follower circuit be used (shown above), which follows the bias
circuit’s gate output. This will result in a high-input impedance,
low-output impedance buffer between the gate output of the
bias circuit and the gate input of the XP1043-QH.
Emitter Follower placed between the
(gate) output of the bias circuit MMIC gate
Mimix Broadband, Inc., 10795 Rockley Rd., Houston, Texas 77099
Tel: [phone] Fax: [phone] mimixbroadband.com
Page 5 of 7
Characteristic Data and Specifications are subject to change without notice. ©2010 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.