Data Sheet

HMC8410

Rev. A | Page 13 of 17

THEORY OF OPERATION

The HMC8410 is a gallium arsenide (GaAs), monolithic

microwave integrated circuit (MMIC), pseudomorphic (pHEMT),

low noise wideband amplifier.

The cascode amplifier uses a fundamental cell of two field effect

transistors (FETs) in series, source to drain. The basic schematic

for the cascode cell is shown in Figure 37, which forms a low

noise amplifier operating from 0.01 GHz to 10 GHz with

excellent noise figure performance.

RFOUT

RFIN

Figure 37. Basic Schematic for the Cascode Cell

The HMC8410 has single-ended input and output ports whose

impedances are nominally equal to 50 Ω over the 0.01 GHz to

10 GHz frequency range. Consequently, it can directly insert

into a 50 Ω system with no required impedance matching

circuitry, which also means that multiple HMC8410 amplifiers

can be cascaded back to back without the need for external

matching circuitry.

The input and output impedances are sufficiently stable vs.

variations in temperature and supply voltage that no impedance

matching compensation is required.

Note that it is critical to supply very low inductance ground

connections to the ground pins as well as to the backside

exposed paddle to ensure stable operation.

To achieve optimal performance from the HMC8410 and prevent

damage to the device, do not exceed the absolute maximum

ratings.