Title :
Microwave low-noise GaAs HBTs
Author :
Dodo, H. ; Amamiya, Y. ; Niwa, T. ; Mamada, M. ; Tanaka, S. ; Shimawaki, H.
Author_Institution :
Optoelectron. & High Frequency Device Res. Labs., NEC Corp., Ibaraki, Japan
Abstract :
In this paper we present our approach to improving microwave noise performance of HBTs. A minimum noise figure of 0.83 dB was obtained at 2 GHz by using an emitter guardring structure which improves the DC current gain particularly at low current densities. We also fabricated HBTs with regrown extrinsic base layers and InGaAs graded base layers which drastically reduce base contact resistance and base transit time, respectively. It is shown that this type of HBTs not only improve the noise-figure at X-band or Ku-band but also make the noise impedance matching easier.
Keywords :
III-V semiconductors; aluminium compounds; contact resistance; current density; gallium arsenide; heterojunction bipolar transistors; impedance matching; microwave bipolar transistors; semiconductor device noise; 0.83 dB; 2 GHz; AlGaAs-GaAs; DC current gain; GaAs HBT; InGaAs; InGaAs graded base layers; Ku-band; X-band; base contact resistance reduction; base transit time reduction; emitter guardring structure; microwave low-noise HBTs; microwave noise performance; minimum noise figure; noise impedance matching; regrown extrinsic base layers; Circuit noise; Equations; Frequency; Gallium arsenide; Heterojunction bipolar transistors; Impedance matching; Linearity; Low-frequency noise; Microwave devices; Noise figure;
Conference_Titel :
Microwave Symposium Digest, 1998 IEEE MTT-S International
Conference_Location :
Baltimore, MD, USA
Print_ISBN :
0-7803-4471-5
DOI :
10.1109/MWSYM.1998.705086
