Amplifier performance of dual emitter HBT for MMIC power amplifier applications

A new emitter/base finger structure of InGaP/GaAs HBT has been designed as a unit cell for multi-finger integration, and evaluated the gain performance compared with the conventional emitter/base structure. We have designed a unit cell composed of 2 emitter fingers with 1 base finger (1B2E, dual emitter) and evaluated the performance compared with the conventional structure: the unit cell composed of 1 emitter finger and 2 base fingers (2B1E). 1B2E has several advantages compared to 2B1E: 2 times of collector current density, thermal stability, and high power gain.