This paper describes AlGaAs/InGaAs and AlGaAs/GaAs Heterojunction Bipolar Transistor (HBT) technologies applicable to power amplifiers for microwave and millimeter-wave frequencies. The performance of the power amplifier is characterized using power added efficiency, which is the function of maximum available gain cutoff frequency (fmax), and collector efficiency. HBT device structure having p+/p regrown extrinsic base, compositionally graded intrinsic base, and hetero guard ring composed of depleted AlGaAs, are shown as technologies to improve fmax. Novel class F matching circuit including harmonic trapping are also shown as a technology to increase collector efficiency. RF power performances of 25.6 dBm (365 mW) saturation power and 23% power added efficiency were obtained at 25.2 GHz.
|Title of host publication||NEC Research and Development|
|Number of pages||8|
|Publication status||Published - 1995 Jan 1|
ASJC Scopus subject areas
- Electrical and Electronic Engineering