A SPICE Sub-Circuit Model for Backward Diode

2019 ◽  
Author(s):  
Wei Wu ◽  
Fengxia Wang ◽  
Andy G. Lozowski
Keyword(s):  
Communication Systems ◽  
Measurement Data ◽  
Differential Resistance ◽  
Negative Resistance ◽  
Tunnel Diode ◽  
Unknown Parameters ◽  
Ultra Low Power ◽  
Spice Model ◽  
Numerical Instabilities ◽  
Computation Analysis

Abstract Backward diode and tunnel diode were formerly used in communication systems and now considered obsolete. Recently, because of their ultra-low threshold voltage at reverse bias condition, the backward diode is used as a rectifier diode for ultra-low power energy harvester. Unfortunately, there are few models available for SPICE simulation or any other computation analysis. The challenge of modeling backward diode and tunnel diode is their negative differential resistance (NDR) and result in a high probability of having numerical instabilities. This paper will first investigate several available mathematical models such as the polynomial model and Ray’s Empirical model, then, a less complex SPICE model based on discrete components sub-circuit will be proposed. All the unknown parameters of this proposed model are optimized based on measurement data using the Levenberg-Marquardt (LM) algorithm. This discrete SPICE model can be easily modified to model other elements with similar negative resistance behavior.

scholarly journals Ultra-Low Power CMOS Readout for Resonant MEMS Strain Sensors

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 973
Author(s):  
Marco Crescentini ◽  
Cinzia Tamburini ◽  
Luca Belsito ◽  
Aldo Romani ◽  
Alberto Roncaglia ◽  
...  
Keyword(s):  
Low Power ◽  
Power Supply ◽  
First Generation ◽  
Negative Resistance ◽  
Low Noise ◽  
Strain Sensors ◽  
Current Conveyors ◽  
Ultra Low Power ◽  
Active Elements ◽  
Low Power Cmos

This paper presents an ultra-low power, silicon-integrated readout for resonant MEMS strain sensors. The analogue readout implements a negative-resistance amplifier based on first-generation current conveyors (CCI) that, thanks to the reduced number of active elements, targets both low-power and low-noise. A prototype of the circuit was implemented in a 0.18-µm technology occupying less than 0.4 mm2 and consuming only 9 µA from the 1.8-V power supply. The prototype was earliest tested by connecting it to a resonant MEMS strain resonator.

scholarly journals A low complexity digital frequency calibration with high jitter immunity for ultra-low-power oscillators

2019 ◽  
Vol 17 ◽  
pp. 145-150
Author(s):  
Markus Scholl ◽  
Ralf Wunderlich ◽  
Stefan Heinen
Keyword(s):  
Low Power ◽  
Communication Systems ◽  
Calibration Method ◽  
Low Complexity ◽  
Frequency Stability ◽  
Wireless Communication Systems ◽  
Ultra Low Power ◽  
Wireless Transceiver ◽  
Digital Frequency ◽  
Frequency Calibration

Abstract. This paper presents a highly efficient digital frequency calibration method for ultra-low-power oscillators in wireless communication systems. This calibration method locks the ultra-low-power oscillator's output frequency to the reference clock of the wireless transceiver during its send- and receive-state to achieve frequency stability over process variation and temperature drifts. The introduced calibration scheme offers high jitter immunity and short locking periods overcoming frequency calibration errors for typical ultra-low-power oscillator's by utilizing non-linear segmented feedback levels. In measurements the proposed calibration method improves the frequency stability of an ultra-low-power 32 kHz oscillator from 53 to 10 ppm ∘C−1 over a wide temperature range for temperature drifts of less than 1 ∘C s−1 with an estimated power consumption of 185 nW while coping with relocking periods of 7 ms.

scholarly journals Dynamic torque calibration by means of model parameter identification

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (2) ◽  
pp. 39 ◽  
Author(s):  
Leonard Klaus ◽  
Barbora Arendacká ◽  
Michael Kobusch ◽  
Thomas Bruns
Keyword(s):  
Frequency Response ◽  
Dynamic Behaviour ◽  
Measurement Data ◽  
Model Parameters ◽  
Dynamic Calibration ◽  
Extended Model ◽  
Unknown Parameters ◽  
Measuring Device ◽  
Torque Transducer ◽  
Least Squares Approach

For the dynamic calibration of torque transducers, a model of the transducer and an extended model of the mounted transducer including the measuring device have been developed. The dynamic behaviour of a torque transducer under test is going to be described by its model parameters. This paper describes the models with these known and unknown parameters and how the calibration measurements are going to be carried out. The principle for the identification of the transducer's model parameters from measurement data is described using a least squares approach. The influence of a variation of the transducer's parameters on the frequency response of the expanded model is analysed.

scholarly journals Link Quality Assessment Algorithm for Heterogeneous Self-organizing Maritime Communications Network

2018 ◽  
Vol 2 ◽  
pp. 32-40
Author(s):  
Krzysztof Bronk ◽  
Adam Lipka ◽  
Rafał Niski
Keyword(s):  
Quality Assessment ◽  
Cellular Networks ◽  
Communication Systems ◽  
Measurement Data ◽  
Link Quality ◽  
Radio Link ◽  
Radio Communication ◽  
Communications Network ◽  
Link Quality Indicator ◽  
Sea Area

The article introduces a method of performing a radio link quality assessment based on the Link Quality Indicator (LQI) which will be calculated for every system that is available. The method presented has been developed during the netBaltic project completed in Poland and generally applies to the so-called maritime zone A, i.e. the sea area where ships are still within the range of shore-based radio communication systems, particularly 3G/LTE cellular networks. The algorithm was developed based on the results of measurements obtained during two separate campaigns. That measurement data served as a basis for the method’s initial assumptions and was utilized during the method’s verification.

A passive SPICE model for rectennas

2018 ◽  
Vol 37 (6) ◽  
pp. 1905-1917
Author(s):  
Polyanna Mara Pereira ◽  
Felipe Campelo ◽  
Takuya Mori ◽  
Hajime Igarashi ◽  
Ricardo Adriano
Keyword(s):  
Computational Cost ◽  
Rational Functions ◽  
Negative Real Part ◽  
Negative Resistance ◽  
Voltage Source ◽  
Numerical Instability ◽  
Content Type ◽  
Electric Circuits ◽  
Spice Model ◽  
Full Wave

Purpose This paper aims to present a SPICE model to represent antennas in receiving mode. The model can be used to evaluate the performance of the antenna when it is coupled to several different nonlinear electric circuits. The proposed methodology is particularly suitable for rectenna applications, as it allows the analysis of different configurations for a rectenna more efficiently than using full-wave analysis simulators coupled directly to each rectifier circuit. Design/methodology/approach The model presented uses reciprocity theory to calculate the ideal voltage source of the Thevenin-equivalent circuit for an antenna. Vector fitting is then used to approximate the model to rational functions that can be converted to Resistor, Inductor and Capacitor circuits. Additional components are added to the circuit to prevent numerical instability. Findings Two rectennas are used to illustrate the performance of the proposed model, one based on a 2.45-GHz rectangular patch antenna and another based on a planar spiral antenna. The second antenna has impedance with positive and negative real parts along the frequency range, which could lead to numerical instabilities. The proposed method is shown to be stable while working with these negative resistance values, which may appear during circuit parameterization. Research limitations/implications The equivalent SPICE circuit model for the antenna makes it easy to simulate nonlinear circuits connected to the antenna and perform transient analyses. The computational cost of antenna analysis is reduced, being more computationally efficient than methods that involve full-wave simulation. This characteristic makes it an interesting approach for working with rectennas, or any application where the time constant of the circuit is much longer than the period of the incident wave. Originality/value For most antenna applications, the numerical stability of the circuit can be achieved using passive enforcement. However, depending on the phase response of the antenna, the impedance that represents its far-field characteristic may present a negative real part, in which case, passive enforcement will fail. In this paper, the problem of numerical instability is solved by introducing an offset resistance and a current-controlled voltage source to the model.

scholarly journals DSP-based Mitigation of RF Front-end Non-linearity in Cognitive Wideband Receivers

Frequenz ◽  
2012 ◽  
Vol 66 (9-10) ◽  
Author(s):  
Michael Grimm ◽  
Rajesh K. Sharma ◽  
Matthias A. Hein ◽  
Reiner S. Thomä
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Communication Systems ◽  
Measurement Data ◽  
Digital Signal ◽  
Software Defined Radios ◽  
Front End ◽  
Non Linear ◽  
Rf Performance ◽  
Processing Techniques

AbstractSoftware defined radios are increasingly used in modern communication systems, especially in cognitive radio. Since this technology has been commercially available, more and more practical deployments are emerging and its challenges and realistic limitations are being revealed. One of the main problems is the RF performance of the front-end over a wide bandwidth.This paper presents an analysis and mitigation of RF impairments in wideband front-ends for software defined radios, focussing on non-linear distortions in the receiver. We discuss the effects of non-linear distortions upon spectrum sensing in cognitive radio and analyse the performance of a typical wideband software-defined receiver. Digital signal processing techniques are used to alleviate non-linear distortions in the baseband signal. A feed-forward mitigation algorithm with an adaptive filter is implemented and applied to real measurement data. The results obtained show that distortions can be suppressed significantly and thus increasing the reliability of spectrum sensing.

Sign in / Sign up

Export Citation Format

Share Document