High-linearity, low DC power monolithic GaAs HBT broadband amplifiers to 11 GHz

Two broadband monolithic amplifiers based on GaAs heterojunction bipolar transistors (HBT) have been developed covering the 0.05-11-GHz frequency band. The hybrid designs reported by B.L. Nelson et al. (1989 IEEE GaAs IC Symp. Digest, Oct. 1989, p.79-82) have been successfully implemented with monolithic microwave IC (MMIC) technology. These amplifiers are the first reported balanced and distributed MMIC HBT amplifiers and represent a significant improvement over MESFET and HEMT approaches in high-linearity, low-DC-power performance for communication and electronic warfare applications. A 5-11-GHz MMIC balanced amplifier designed for high linearity produces +33-dBm third-order output intercept point (IP3) with 7.5-dB associated gain and less than 160-mW DC-power consumption. A 0.05-9-GHz distributed amplifier designed for low DC power and high gain consumes less than 50-mW and provides 6-10-dB gain at nominal bias. Device fabrication and characteristics are described.<>