Data Sheet

ADL8140

THEORY OF OPERATION

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Rev. 0 | 14 of 18

The ADL8140 is a gallium arsenide (GaAs), monolithic microwave

integrated circuit (MMIC), pseudomorphic high electron mobility

transistor (pHEMT), LNA with an integrated bias inductor and AC-

coupling capacitors. A simplified schematic is shown in Figure 49.

To set the drain bias current, connect an external resistor between

the RBIAS and VDD pins.

The ADL8140 has AC-coupled, single-ended input and output ports

with impedances that are nominally equal to 50 Ω over the 10 GHz

to 18 GHz frequency range. No external matching components are

required. While the RF output path is AC-coupled, there is a DC

path to ground on the RFOUT side of the AC-coupling capacitor.

Figure 49. Simplified Schematic