MRF1518T1 Motorola, MRF1518T1 Datasheet - Page 12

• Manufacturer Part Number: MRF1518T1
• Description: The RF MOSFET Line RF POWER FIELD EFFECT TRANSISTOR
• Manufacturer: Motorola

MOUNTING
assumes a majority of the 0.065 x 0.180 source contact on
the back side of the package is in good contact with an
appropriate heat sink. As with all RF power devices, the goal
of the thermal design should be to minimize the temperature
at the back side of the package. Refer to Motorola
Application Note AN4005/D, “Thermal Management and
Mounting Method for the PLD–1.5 RF Power Surface Mount
Package,” and Engineering Bulletin EB209/D, “Mounting
Method for RF Power Leadless Surface Mount Transistor” for
additional information.
AMPLIFIER DESIGN
bipolar transistors are suitable for this device. For examples
see Motorola Application Note AN721, “Impedance Matching
Networks Applied to RF Power Transistors.” Large–signal
MRF1518T1
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The specified maximum thermal resistance of 2 C/W
Impedance matching networks similar to those used with
impedances are provided, and will yield a good first pass
approximation.
unilateral. This coupled with the very high gain of this device
yields a device capable of self oscillation. Stability may be
achieved by techniques such as drain loading, input shunt
resistive loading, or output to input feedback. The RF test
fixture implements a parallel resistor and capacitor in series
with the gate, and has a load line selected for a higher
efficiency, lower gain, and more stable operating region.
provides a useful tool for selection of loading or feedback
circuitry to assure stable operation. See Motorola Application
Note AN215A, “RF Small–Signal Design Using Two–Port
Parameters” for a discussion of two port network theory and
stability.
Since RF power MOSFETs are triode devices, they are not
Two–port stability analysis with this device’s S–parameters
MOTOROLA RF DEVICE DATA