A low-noise 2-21 GHz monolithic distributed amplifier utilizing 0.35-micrometer-gate-length HEMT devices has achieved 12±0.5 dB of gain. This represents the highest gain reported for a distributed amplifier using single FET gain cells. A record low noise figure of 3 dB was achieved midband (4-12 GHz). The circuit design utilizes five HEMT transistors Of varying width with gates fabricated by E-beam lithography. The same amplifier fabricated with 0.35- \i m-gate-length MESFET's in place of the HEMT devices resulted in 9.5 ±0.5 dB of gain across the 2-20 GHz band. This record performance level for a MESFET distributed amplifier is used to determine that the use of HEMT devices rather than the small gate lengths is primarily responsible for the HEMT amplifier performance.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering