An HBT noise model valid up to transit frequency

The numerical properties of a deterministic Boltzmann equation solver based on a spherical harmonics expansion of the distribution function are analyzed and improved. A fully coupled discretization scheme of the Boltzmann and Poisson equations is proposed, where stable equations are obtained based on the H-transformation. It is explicitly shown that the resultant Jacobian matrix for the zeroth order component has property M for a first order expansion, which improves the stability even of higher order expansions. The detailed dependence of the free-streaming operator and the scattering operator on the electrostatic potential is exactly considered in the Newton-Raphson scheme. Therefore, convergence enhancement is achieved compared with previous Gummel-type approaches. This scheme is readily applicable to small-signal and noise analysis. As numerical examples, simulation results are shown for a silicon n + nn + structure including a magnetic field, an SOI NMOSFET and a SiGe HBT.

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“…29. The electron noise current transit time, τ n , which is given by [72,73] S elec I B I C = 2qI C (e jωτ n − 1),…”

Section: Sige Hbtmentioning

confidence: 99%

A fully coupled scheme for a Boltzmann-Poisson equation solver based on a spherical harmonics expansion

Hong

Jungemann

2009

J Comput Electron

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“…The CRT curves, however, are shifted in voltage due to the change of breakdown voltage with temperature (Buzhan 2001). (3) Preamplifier-the improvement in electronics noise over this small temperature range can be assumed to be negligible (Rudolph et al 1999).…”

Section: Summary and Discussionmentioning

confidence: 99%

Optimizing timing performance of silicon photomultiplier based scintillation detectors

Yeom

Vinke

Levin

2012

2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC)

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Precise timing resolution is crucial for applications requiring photon time-of-flight (ToF) information such as ToF positron emission tomography (PET). Silicon photomultipliers (SiPM) for PET, with their high output capacitance, are known to require custom preamplifiers to optimize timing performance. In this paper, we describe simple alternative front-end electronics based on a commercial low-noise RF preamplifier and methods that have been implemented to achieve excellent timing resolution. Two radiation detectors with L(Y)SO scintillators coupled to Hamamatsu SiPMs (MPPC S10362-33-050C) and front-end electronics based on an RF amplifier (MAR-3SM+), typically used for wireless applications that require minimal additional circuitry, have been fabricated. These detectors were used to detect annihilation photons from a Ge-68 source and the output signals were subsequently digitized by a high speed oscilloscope for offline processing. A coincident resolving time (CRT) of 147 ± 3 ps FWHM and 186 ± 3 ps FWHM with 3 × 3 × 5 mm 3 and with 3 × 3 × 20 mm 3 LYSO crystal elements were measured, respectively. With smaller 2 × 2 × 3 mm 3 LSO crystals, a CRT of 125 ± 2 ps FWHM was achieved with slight improvement to 121 ± 3 ps at a lower temperature (15°C). Finally, with the 20 mm length crystals, a degradation of timing resolution was observed for annihilation photon interactions that occur close to the photosensor compared to shallow depth-of-interaction (DOI). We conclude that commercial RF amplifiers optimized for noise, besides their ease of use, can produce excellent timing resolution comparable to best reported values acquired with custom readout electronics. On the other hand, as timing performance degrades with increasing photon DOI, a head-on detector configuration will produce better CRT than a side-irradiated setup for longer crystals.

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“…It is for this reason that in practice, noise sources are often described independently from Y-parameters using dedicated modeling equations involving the use of dedicated parameters. One popular model is the transport model [17,18]. That model, however, is not sufficiently accurate.…”

Section: Noise Sources Of the Intrinsic Transistormentioning

confidence: 99%

“…Using the proposed models, we compare noise sources and noise parameters for the extended van Vliet model with and without the input NQS effect. Using the proposed NQS model, we extend the popular transport noise model [17,18] by using two noise related delay times to reproduce the extended van Vliet model, so that noise can be accurately modeled in lack of accurate NQS Y-parameters. This is highly desired in practice, as inaccurate noise source, rather than inaccurate Y-parameters, is the main reason for the poor noise accuracy of current noise models, as we will show below.…”

Section: Introductionmentioning

confidence: 99%

Modeling the input non-quasi-static effect in small signal equivalent circuit based on charge partitioning for bipolar transistors and its impact on RF noise modeling

Xia

Niu

2010

Solid-State Electronics

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An HBT noise model valid up to transit frequency

Cited by 68 publications

References 10 publications

A fully coupled scheme for a Boltzmann-Poisson equation solver based on a spherical harmonics expansion

A fully coupled scheme for a Boltzmann-Poisson equation solver based on a spherical harmonics expansion

Optimizing timing performance of silicon photomultiplier based scintillation detectors

Modeling the input non-quasi-static effect in small signal equivalent circuit based on charge partitioning for bipolar transistors and its impact on RF noise modeling

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