32.0-45.0 GHz GaAs MMIC
Transmitter
August 2006 - Rev 02-Aug-06
App Note [1] Biasing
- As shown in the bonding diagram, this device is operated by separately biasing Vd1 and Vd2 with Vd(1,2)=4.0V,
U1004
Id1=160mA and Id2=145mA. Additionally, a mixer and doubler bias are also required with Vg3=Vg4=-0.5V. Adjusting Vg3 and Vg4 above or
below this value can adversely affect conversion gain, LO/RF isolation and intercept point performance. 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 voltage needed to do this is -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 Parallel Stage Bias (Recommended for general applications) -- The same as Individual Stage Bias but all the drain or gate pad DC bypass
capacitors (~100-200 pF) can be combined. Additional DC bypass capacitance (~0.01 uF) is also recommended to all DC or combination (if
gate or drains are tied together) of DC bias pads.
For Individual Stage Bias -- Each DC pad (Vd1,2 and Vg1,2,3,4) 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.
MTTF Tables (TBD)
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
deg Celsius
deg Celsius
deg Celsius
Rth
MTTF Hours
FITs
C/W
C/W
C/W
E+
E+
E+
E+
E+
E+
Bias Conditions:
Vd1=Vd2=4.0V, Id1=160 mA, Id2=145 mA
Typical Application
RF OUT
37.0-39.5 GHz
XP1005
XU1004
Coupler
IF In
2 GHz
Mixer
X
Buffer
X2
LO(+2.0dBm)
17.5-18.75 GHz (USB Operation)
19.5-20.75 GHz (LSB Operation)
Mimix Broadband MMIC-based 32.0-45.0 GHz Receiver Block Diagram
(Changing LO and IF frequencies as required allows design to operate as high as 45 GHz)
Mimix Broadband's 32.0-45.0 GHz XU1004 GaAs MMIC Transmitter can be used in saturated radio applications and linear modulation
schemes up to 128 QAM. The receiver can be used in upper and lower sideband applications from 32.0-45.0 GHz.
Mimix Broadband, Inc., 10795 Rockley Rd., Houston, Texas 77099
Tel: 281.988.4600 Fax: 281.988.4615 mimixbroadband.com
Page 4 of 7
Characteristic Data and Specifications are subject to change without notice.
©2006
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.
MIMIX [ MIMIX BROADBAND ]
