MMIC AN700

INTRODUCTION
This application note describes the use and handling of AMCOM's BM MMIC power
amplifiers. The amplifiers are housed in a 10-pin low cost surface mountable, ceramic
package. The MMIC can be handled by standard pick and place equipment.
ELECTRICAL SCHEMATIC
Figure 1 shows the detailed schematic and pin assignment of AMCOM's BM MMIC
power amplifiers. External DC decoupling and filtering components are added to
ensure stability of the amplifier and to prevent any possible spurious signal due to
noisy supplies. A good ground is required for maintaining stability. The following table describes the pin
assignment of the amplifier:
BM PIN ASSIGNMENT
Pin Signal Description
1, 2, 10 Vds Positive Drain
Voltage
3 RF in RF power input
4, 9 Ground RF and DC Ground
5, 6, 7 Vgs Negative gate
Voltage
8 RF out RF power output
BIAS CONSIDERATIONS
Drain bias
The amplifier is designed to operate within specifications when biased with drain voltage/current as specified in
datasheet. If the MMIC is mounted on a ridged heat sink (see Figure 4A), it can be biased at a higher Vds (about
1-2 V higher). In all cases the absolute maximum rating for voltage, current, or power dissipation must not be
exceed. The DC drain current can be controlled by the negative gate voltage. If the MMIC is biased with a current
and/or voltage less than Idq then the gain and P1dB will be reduced.
Gate bias
As with all GaAs amplifiers, it is important to ensure that the gate bias is present before applying the drain voltage.
Without gate control, the drain current will rise to a level that is potentially destructive to the MMIC; therefore, it is