Generation‐recombination noise analysis in heavily doped p‐type GaAs transmission line models

Low-frequency noise measurements are performed on heavily doped p-type GaAs transmission line models. Excess noise exhibits 1/f noise and generation-recombination (GR) noise components. A study of the GR components vs device geometry shows the spectral densities due to contact resistances to be negligible. Thus the noise sources due to the volume resistances are predominant, and have to be located in the bulk layer or in the space-charge region of the devices. These two possibilities concerning the location of the GR noise sources are investigated. For both cases, expressions for the variance and the relaxation time associated to fluctuations in the charge carriers are given. The comparison between the experimental data with the theoretical results shows that the GR noise sources are located in all probability in the space-charge region

Generation‐recombination noise in submicron semiconductor layers: Influence of the edge

In highly doped thin semiconductor layers one often observes generation-recombination (g-r) noise with a broadened Lorentzian-like spectrum. In a theoretical analysis we have shown that such a spectrum can be ascribed to g-r processes between conduction band and monoenergetic traps in the edge of the layers

Generation‐recombination noise in submicron semiconductor layers: Influence of the edge

In highly doped thin semiconductor layers one often observes generation-recombination (g-r) noise with a broadened Lorentzian-like spectrum. In a theoretical analysis we have shown that such a spectrum can be ascribed to g-r processes between conduction band and monoenergetic traps in the edge of the layers

Effects of CW interferences on a 5 GHz monolithic VCO

International audienceThe paper presented here is part of the electromagnetic susceptibility studies conducted on active circuits. An electromagnetic interference (EMI) is injected on an integrated voltage controlled oscillator (VCO). We describe the different effects observed on its operation mode when the circuit is subject to an EMI or high frequency signal. Three operating modes are observed. Some of them are confronted with Razavi's theory. Others highlight new phenomena in function of the aggression power

On the effect of amplitude modulated EMI injected on a PLL active filter

International audienceIn this paper, the effect of an Electromagnetic Interference (EMI) modulated in amplitude on an Operational Amplifier (Op. Amp.), first as a standalone circuit and then integrated in a microwave Phase-Locked Loop (PLL) is studied. In both cases, the EMI is injected through a magnetic near field probe. First, a CW sinusoidal EMI is injected on the input tracks of the Op. Amp. alone in order to determine resonance frequencies. Then, these resonance frequencies are used as carriers to inject amplitude modulated EMI. Then, the Op. Amp. is integrated into a PLL. The susceptibility of the PLL when an EMI modulated in amplitude is injected on the Op. Amp. is carried out. Parameters of the modulated signal leading to the most sensitive perturbation effects are presented

Generation‐recombination noise analysis in heavily doped p‐type GaAs transmission line models

Low-frequency noise measurements are performed on heavily doped p-type GaAs transmission line models. Excess noise exhibits 1/f noise and generation-recombination (GR) noise components. A study of the GR components vs device geometry shows the spectral densities due to contact resistances to be negligible. Thus the noise sources due to the volume resistances are predominant, and have to be located in the bulk layer or in the space-charge region of the devices. These two possibilities concerning the location of the GR noise sources are investigated. For both cases, expressions for the variance and the relaxation time associated to fluctuations in the charge carriers are given. The comparison between the experimental data with the theoretical results shows that the GR noise sources are located in all probability in the space-charge region

Comparison of noise between passivated and unpassivated AlGaAs/GaAs and GaInP/GaAs HBTs

A comparison of AlGaAs/GaAs and GaInP/GaAs heterojunction bipolar transistors (HBTs) of similar geometry is presented. First-order measurements show the importance of recombination currents in AlGaAs/GaAs transistors. Passivation improves the d.c. performance of GaInP/GaAs devices only. Low-frequency noise measurements are then performed. Spectra show 1/f noise and g - r components. White noise is never reached. An analysis of each excess noise component is performed versus bias current. The 1/f noise level and bias dependence is quite similar in all transistors. Generation - recombination noise component levels are more important in AlGaAs/GaAs HBTs. This is attributed to characteristic traps. For both types of HBT no appreciable influence from the passivation is observed and noise sources are found to be located principally in the emitter - base junction