Abstract

This paper presents the low frequency noise of double lieterojunction bipolar transistor (DHBTs) based on GalnP/GaAs/GalnP system. From static measurements, we can observe that both surface recombination along the emitter finger and bulk recombination in the extrinsic base region exist in these structure. S parameters measurements show very interesting microwave capabilities with cut-off frequency and maximum oscillation larger than 30 GHz. Concerning the noise properties, the results indicate that both 1/f and generation-recombination are present in DHBT. Both the input noise current and input noise voltage is inversely proportional to the emitter length. The inspection of the correlation between the noise generators reveals that the resistive parts of the device play a role on the overall noise component. Further, we have shown that the noise source at the output is not negligeable. Finally, a comparative noise study between emitter-up and collector-up DHBTs indicate that the noise current source is lower for co[lector-up DHBT than for emitter-up one related to a lower surface recombination rate.