500-6000 MHz
Dual, Ultra Low Noise, High IP3 Amplifier
May 2006 - Rev 24-May-06
CDQ0303-QS
Considerations When Designing for Optimum Noise Figure Using Noise Parameters - For any two-port network, the noise figure gives a
measure of the amount of noise added to a signal transmitted through that network. In this datasheet we have given the NFmin and the
corresponding optimum source resistance values for the device under various bias conditions. NFmin represents the true minimum noise figure
when the device is presented with an impedance matching network that transforms the source impedance typically 50 ohms to that optimum
noise matching impedance reffered to as Gopt. All stability considerations still apply, of course. If the calculated Rollet stability factor (K) is less than
1, then the source and load reflection coefficients must be carefully chosen. For an accurate graphical depiction of the unstable regions, it is best
to draw stability circles.
In practice the impedance that minimizes the noise figure is different from the impedance that minimizes the return loss. Matching techniques
such as inductive feedback will be used to bring the noise match closer to this gain match. An additional inherent danger of this technique is the
increased instability of the design at higher frequencies. As the frequency increases the amount of feedback to the devices source up to an
oscillation level. This issue can be reduced by carefully choosing the input and output matching topology so that the transducer gain is limited at
the frequency of potential oscillation. Design of a high pass / los pass matching network on the input and output is one solution that addresses
this problem. Careful simulation is essential using the wideband s-parameters provided and can only be achieved through careful modeling of all
components utilized in the design, including:
1. Accurate high frequency models for all surface mount components used.
2. Accurate models of the board characteristics including loss tangents and metal thickness.
3. Use of Via holes and via pads instead of perfect grounds where used.
In any case if the reflection coefficient of the chosen matching network is other than Gopt, then the noise figure of the device will be greater than
NFmin. The losses of the matching circuits are also non-zero and it must be considered that the noise figure of the completed amplifier is equal to
the noise figure of the device plus the losses of the matching network preceding the device.
The losses of the matching networks are related to the Q of the components and associated printed circuit board loss. In general larger gate width
devices will typically have a lower Gopt as compared to smaller gate width devices. Matching to higher impedance devices requires very hi-Q
components in order to minimize circuit losses. The main reason for using smaller gate width devices is the trade-off of current consumption and
optimum noise performance. The CDQ0303-QS is a 600um gate width device has a minimum noise figure of 0.08 dB and a Gopt of Mag 0.83, Ang
36.63, making it significantly easier to match than competitive devices. Associated gain Ga is 20.82 dB.
Device Non-Linear Model - Mimix develops its own non-linear model based on its own internal device characterization. The model is verified in
different simulators and compared to the original data from which it was extracted.
Die Model - Gate Width = 600 µm, Optimized for 0.1 GHz to 26.0 GHz
C
Cgs
Cdg
Cds
Gm
Ri
Tau
Rs
Rd
1.04 pF
0.07 pF
0.1 pF
303 mS
2.2 Ohm
0.06 ps
1.28
Rg
Ls
Ld
0.29
0.04 nH
0.1 nH
0.05 nH
5 mil Gold wire (1 mil dia)
5 mil Gold wire (1 mil dia)
3 mil Gold wire (1 mil dia)
0.10 pF
Cpd
PCG
PCD
PLS
PLG
PLD
PCDG
0.08 pF
0.195 pF
0.21 pF
0.085 nH
0.525 nH
0.55 nH
0.005 pF
SRL
WIRE
BG
WIRE
BD
SRL
PCDG
PLG1
PLD
u u u u
u u u u
PSFET
C
PCD
Parker Skellern
W=600
C
PCG
Lg
WIRE
BS
BG
BD
BS
SRL
PLS
1.35
Cpg
The PSFET is a Mimix imple-
mentation of the Parker Skellern
large signal model. The model is
available as an ADS project file
on-line at: www.mimixbroadband.com
Typical Reflow Profiles
Reflow Profile
SnPb
Pb Free
3-4 ºC/sec
Ramp Up Rate
3-4 ºC/sec
Activation Time and Temperature
Time Above Melting Point
Max Peak Temperature
Time Within 5 ºC of Peak
Ramp Down Rate
60-120 sec @ 140-160 ºC
60-150 sec
60-180 sec @ 170-200 ºC
60-150 sec
240 ºC
265 ºC
10-20 sec
10-20 sec
4-6 ºC/sec
4-6 ºC/sec
Page 10 of 14
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. ©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 ]
