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An empirical bipolar transistor nonlinear noise model for the large-signal (LS) noise analysis of microwave circuits is described. The model is derived according to the charge-controlled nonlinear noise behavioral modeling approach, and includes non-linearly controlled equivalent noise (EN) generators describing the low-frequency (LF) noise up-conversion encountered in LS RF operation. LS-modulated shot-noise sources and parametric LF noise in parasitic resistors are also taken into account for improved model accuracy. Details for the implementation of the proposed cyclostationary EN generators in the framework of a computer-aided design tool are presented. As an application example, a simplified version of the proposed nonlinear noise model for two GaInP--GaAs HBTs has been formulated and empirically characterized on the basis of both bias-dependent LF noise and phase-noise measurements. Measured and simulated noise performance of a monolithic voltage-controlled oscillator over a set of different operating conditions is shown for the validation of the proposed approach. Index Terms--Cyclostationary noise, low-frequency (LF) noise, low phase noise (LPN), noise up-conversion, nonlinear noise model.

The effects of a microwave tone on the low-frequency noise properties of GaInP/GaAs heterojunction bipolar transistors are investigated both experimentally and through simulations, to ascertain which modulation strategy should be adopted for the low-frequency noise sources when they should face large signal conditions, as in the cases of oscillators and mixers. Experiments revealed that the application of a microwave tone on the base terminal reduces the magnitude of the base current and collector current fluctuation spectra.

An original technique, based on a full noise characterization, to discriminate the low-frequency noise sources in modern sub-micron bipolar devices, is presented. It is demonstrated that the correlation resistance can reveal the presence of excess noise sources located in the extrinsic base region of the transistor.

An experimental design for the direct full low-frequency noise characterization of Si/SiGe heterojunction bipolar transistors is presented. This design is based on current/voltage conversion through transimpedance amplifiers.

Three different electrical stress tests on InP-based high-electron mobility transistors (HEMTs) and their implications concerning reliability are discussed. Hot electron stress, RF overdrive stress and transmission line pulse measurements are investigated to fill a gap in this research area. Until now, reliability assessment of HEMTs has been mainly conducted using high-temperature accelerated stress experiments, while the field of purely electrical stressing has been relatively ignored.

The burn-in effect in microwave GaInP/GaAs heterojunction bipolar transistors for various dc current stresses is studied. Results show that the burn-in effect is caused by reduced surface recombination at the extrinsic base surface around the emitter parameter. Defects at the passivation/semiconductor interface are also associated with the recombination centers and that these centers are passivated by hydrogen atoms released from C-H complexes under stress. In addition, it is shown the reliability and electronic performance of ledge passivation technology is better compared to SiN passivation technology.

A large number of interesting applications have been discovered for three-terminal, gallium arsenide-based pseudo-morphic high electron mobility transistors or PHEMTs. Certain PHEMT devices designed for millimeter-wave, low-noise applications are tested for hot electron degradation, which is demonstrated in the hot electron stress on both the dc and rf characteristics.