ADL9006

Data Sheet

Rev. 0 | Page 12 of 14

THEORY OF OPERATION

The ADL9006 is a GaAs, pHEMT, MMIC low noise amplifier.

The basic architecture of the ADL9006 is that of a single-supply,

biased, cascode distributed amplifier with an integrated RF choke

for the drain. A simplified schematic of this architecture is

shown in Figure 37.

RFIN

RFOUT

TRANSMISSION LINE

TRANSMISSION LINE

Figure 37. Architecture and Simplified Schematic

Though the gate bias voltages of the upper field effect transistors

(FETs) are set internally by a resistive voltage divider tapped off

means of changing the gate bias of the upper FETs. Adjustment

changes the gate bias of the upper FETs, thus affecting gain

changes, depending on the frequency (see Figure 17).