Abstract :
The influence of Al content on the RF noise characteristics of Al xGa1-xAs/GaAs heterojunction bipolar transistors (HBT´s) is presented. It is shown that the minimum noise figure (Fmin) at 2 GHz is reduced by increasing the Al mole fraction (x). This observed improvement in noise figure is directly correlated to the differences in dc current gain. The lowest measured Fmin(2 GHz) of HBT´s with emitter dimensions 2×(3.5×30) μm2, were 1.3, 1.61, and 2.1 dB for x=0.35, 0.30, and 0.25 devices, respectively at Ic=3 mA. The measured results were found to agree well with calculated values over a wide range of collector currents
Keywords :
III-V semiconductors; UHF bipolar transistors; aluminium compounds; gallium arsenide; heterojunction bipolar transistors; semiconductor device noise; 1.3 to 2.1 dB; 2 GHz; Al composition; AlGaAs-GaAs; AlGaAs/GaAs heterojunction bipolar transistors; DC current gain; RF noise; minimum noise figure; Artificial intelligence; Bipolar transistors; Current measurement; Gallium arsenide; Heterojunction bipolar transistors; Instruments; Noise figure; Passivation; Radio frequency; Thermal resistance;
