Although often associated with power amplifiers, E-pHEMT devices
are also quite capable of supporting the design of efficient
low-noise amplifiers. Low-noise amplifiers (LNAs) for high-
frequency applications have been based on GaAs metal-epitaxial-
semiconductor field-effect-transistor (MESFET) and depletion-
mode pseudomorphic-high-electron-mobility-transistor (pHEMT)
technologies for some time. Semiconductor technologies such as
GaAs heterojunction-bipolar-transistor (HBT) and the newer
enhancement-mode pHEMT (E-pHEMT) technologies have been used
primarily for power-amplifier (PA) applications. Still, the many
outstanding characteristics of E-pHEMT devices also make them
suitable for use in high-frequency LNAs capable of wide
frequency coverage, including a 100-to-500-MHz LNA which will be
revealed here. For PAs, the performance of E-pHEMT technology
offers many well-suited characteristics, including: - Saturated
drain-source current(Idss) of less than 10 µA at room
temperature. - Drain current (Id) of approx