A 5-bit, 87-fs Step, Constant-Slope, Charge-Sharing-Based Encoding Digital-to-Time Converter in 130nm CMOS

Background & Objective: In this paper, a modified pseudo domino configuration has been proposed to improve the leakage power consumption and Power Delay Product (PDP) of dynamic logic using Carbon Nanotube MOSFETs (CN-MOSFETs). The simulations for proposed and published domino circuits are verified by using Synopsys HSPICE simulator with 32nm CN-MOSFET technology which is provided by Stanford. Methods: The simulation results of the proposed technique are validated for improvement of wide fan-in domino OR gate as a benchmark circuit at 500 MHz clock frequency. Results: The proposed configuration is suitable for cascading of the high performance wide fan-in circuits without any charge sharing. Conclusion: The performance analysis of 8-input OR gate demonstrate that the proposed circuit provides lower static and dynamic power consumption up to 62 and 40% respectively, and PDP improvement is 60% as compared to standard domino circuit.

Download Full-text

Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors

Sensors ◽

10.3390/s21093260 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3260

Author(s):

Kjell A. L. Koch-Mehrin ◽

Sarah L. Bugby ◽

John E. Lees ◽

Matthew C. Veale ◽

Matthew D. Wilson

Keyword(s):

Carrier Transport ◽

Hole Transport ◽

Uniform Electric Field ◽

Photon Flux ◽

High Flux ◽

Charge Sharing ◽

Cdte Detector ◽

Charge Loss ◽

Cdznte Detectors ◽

Detector Model

Cadmium zinc telluride (CdZnTe) detectors are known to suffer from polarization effects under high photon flux due to poor hole transport in the crystal material. This has led to the development of a high-flux capable CdZnTe material (HF-CdZnTe). Detectors with the HF-CdZnTe material have shown promising results at mitigating the onset of the polarization phenomenon, likely linked to improved crystal quality and hole carrier transport. Better hole transport will have an impact on charge collection, particularly in pixelated detector designs and thick sensors (>1 mm). In this paper, the presence of charge sharing and the magnitude of charge loss were calculated for a 2 mm thick pixelated HF-CdZnTe detector with 250 μm pixel pitch and 25 μm pixel gaps, bonded to the STFC HEXITEC ASIC. Results are compared with a CdTe detector as a reference point and supported with simulations from a Monte-Carlo detector model. Charge sharing events showed minimal charge loss in the HF-CdZnTe, resulting in a spectral resolution of 1.63 ± 0.08 keV Full Width at Half Maximum (FWHM) for bipixel charge sharing events at 59.5 keV. Depth of interaction effects were shown to influence charge loss in shared events. The performance is discussed in relation to the improved hole transport of HF-CdZnTe and comparison with simulated results provided evidence of a uniform electric field.

Download Full-text

Sea Topography of the Ionian and Adriatic Seas Using Repeated GNSS Measurements

Water ◽

10.3390/w13060812 ◽

2021 ◽

Vol 13 (6) ◽

pp. 812

Author(s):

Sotiris Lycourghiotis

Keyword(s):

Satellite System ◽

Geoid Model ◽

Sea Surface Topography ◽

Mean Sea Surface ◽

The Mean ◽

A New Technique ◽

Gnss Measurements ◽

Global Navigation Satellite ◽

Constant Slope ◽

Ionian And Adriatic Seas

The mean sea surface topography of the Ionian and Adriatic Seas has been determined. This was based on six-months of Global Navigation Satellite System (GNSS) measurements which were performed on the Ionian Queen (a ship). The measurements were analyzed following a double-path methodology based on differential GNSS (D-GNSS) and precise point positioning (PPP) analysis. Numerical filtering techniques, multi-parametric accuracy analysis and a new technique for removing the meteorological tide factors were also used. Results were compared with the EGM96 geoid model. The calculated differences ranged between 0 and 48 cm. The error of the results was estimated to fall within 3.31 cm. The 3D image of the marine topography in the region shows a nearly constant slope of 4 cm/km in the N–S direction. Thus, the effectiveness of the approach “repeated GNSS measurements on the same route of a ship” developed in the context of “GNSS methods on floating means” has been demonstrated. The application of this approach using systematic multi-track recordings on conventional liner ships is very promising, as it may open possibilities for widespread use of the methodology across the world.

Download Full-text

A 1T2C FeCAP-Based In-Situ Bitwise X(N)OR Logic Operation with Two-Step Write-Back Circuit for Accelerating Compute-In-Memory

Micromachines ◽

10.3390/mi12040385 ◽

2021 ◽

Vol 12 (4) ◽

pp. 385

Author(s):

Qiao Wang ◽

Donglin Zhang ◽

Yulin Zhao ◽

Chao Liu ◽

Qiao Hu ◽

...

Keyword(s):

Nonvolatile Memory ◽

High Reliability ◽

Charge Sharing ◽

Operation Speed ◽

Sharing Function ◽

Logic Operations ◽

A Charge ◽

Process Compatibility ◽

Ferroelectric Capacitors

Ferroelectric capacitors (FeCAPs) with high process compatibility, high reliability, ultra-low programming current and fast operation speed are promising candidates to traditional volatile and nonvolatile memory. In addition, they have great potential in the fields of storage, computing, and memory logic. Nevertheless, effective methods to realize logic and memory in FeCAP devices are still lacking. This study proposes a 1T2C FeCAP-based in situ bitwise X(N)OR logic based on a charge-sharing function. First, using the 1T2C structure and a two-step write-back circuit, the nondestructive reading is realized with less complexity than the previous work. Second, a method of two-line activation is used during the operation of X(N)OR. The verification results show that the speed, area and power consumption of the proposed 1T2C FeCAP-based bitwise logic operations are significantly improved.

Download Full-text

Modeling an Aquifer: Numerical Solution to the Groundwater Flow Equation

Mathematical Problems in Engineering ◽

10.1155/2019/1613726 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

V. Vázquez-Báez ◽

A. Rubio-Arellano ◽

D. García-Toral ◽

I. Rodríguez Mora

Keyword(s):

Stationary Flow ◽

Flow Equation ◽

Computational Tool ◽

Groundwater Dynamics ◽

Isotropic Media ◽

Groundwater Flow Equation ◽

The Finite Difference Method ◽

Anisotropic Soil ◽

Constant Slope

We present a model of groundwater dynamics under stationary flow and, governed by Darcy’s law of water motion through porous media, we apply it to study a 2D aquifer with water table of constant slope comprised of a homogeneous and isotropic media; the more realistic case of an homogeneous anisotropic soil is also considered. Taking into account some geophysical parameters we develop a computational routine, in the Finite Difference Method, which solves the resulting elliptic partial equation, both in a homogeneous isotropic and in a homogeneous anisotropic media. After calibration of the numerical model, this routine is used to begin a study of the Ayamonte-Huelva aquifer in Spain, a modest analysis of the system is given, and we compute the average discharge vector as well as its root mean square as a first predictive approximation of the flux in this system, providing us a signal of the location of best exploitation; long term goal is to develop a complete computational tool for the analysis of groundwater dynamics.

Download Full-text