scholarly journals Isomorphic Circuits of Independent Amplitude Tunable Voltage-Mode Bandpass Filters and Quadrature Sinusoidal Oscillators

2021 ◽  
Vol 11 (16) ◽  
pp. 7431
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen ◽  
Yitsen Ku ◽  
Wei-Yuan Chen

This paper presents isomorphic circuits of voltage-mode (VM) non-inverting bandpass filters (NBPFs) and VM quadrature sinusoidal oscillators (QSOs) with independent amplitude control functionality. The proposed VM NBPFs and VM QSOs exhibit low-output impedance and independent amplitude control, which are important for easily cascading the VM operation and independent control of the amplitude gain. The proposed isomorphic circuits employ three LT1228 commercial integrated circuits (ICs), two grounded capacitors, two grounded resistors and one floating resistor. The use of grounded capacitors is beneficial for the implementation of the IC. Both NBPFs have a high-input impedance and have a wide range of independent amplitude tunable passband gain without affecting the quality factor (Q) and center frequency (fo). The Q and fo parameters of the proposed NBPFs are orthogonal tunability. By feeding back each input signal to the output response of the NBPF, two VM fully uncoupled QSOs are also proposed. The proposed VM fully uncoupled QSOs have two quadrature sinusoidal waveforms with two low-output impedances and one independent amplitude tunable sinusoidal waveform. The frequency of oscillation (FO) and the condition of oscillation (CO) are fully uncoupled and controlled electronically. The performances of the proposed isomorphic circuits have been tested with a ±5 volt power supply and are demonstrated by experimental measurements which confirm the theoretical assumptions.

2010 ◽  
Vol 19 (05) ◽  
pp. 1069-1076 ◽  
Author(s):  
ABHIRUP LAHIRI

A number of sinusoidal oscillators using current differencing buffered amplifiers (CDBAs) have been reported in the literature. However, only three of them are canonic quadrature oscillators (i.e., requiring two capacitors). The aim of this letter is to present additional realizations of single/dual-resistance-controlled quadrature oscillators using CDBAs. Four voltage-mode quadrature oscillators are proposed, which provide the following advantageous features: (i) use of reduced and canonic component count, viz. two CDBAs, three/four resistors and two capacitors, (ii) all passive components are grounded or virtually grounded, which is favorable from integration point of view and (iii) independent and non-interactive resistor control of the condition of oscillation (CO) and the frequency of oscillation (FO). Simulation results verifying the workability of the proposed circuits have been included.


2019 ◽  
Vol 29 (04) ◽  
pp. 2050052
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen

This paper presents two new voltage-mode sinusoidal oscillators based on voltage differencing inverting buffered amplifier (VDIBA). The first proposed circuit exhibits independent and electronic control of oscillation condition by using the bias current of the VDIBA. The proposed configuration contains only single VDIBA, two grounded capacitors and two resistors, which are the least number of active components and the minimum number of passive components necessary for realizing voltage-mode oscillator topology. The second proposed circuit exhibits independent and electronic control on the condition of oscillation without affecting the oscillation frequency by adjusting the separate bias currents of the VDIBAs. The proposed configuration contains two VDIBAs, two grounded capacitors and one resistor, which can provide four quadrature voltage outputs simultaneously. Both proposed circuits enjoy only two grounded capacitors, which are suitable for monolithic integration. HSpice simulations and experimental results are included to confirm the theoretical analysis.


Author(s):  
E.D. Wolf

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.


Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.


Author(s):  
Richard C. Jaeger ◽  
Jun Chen ◽  
Jeffrey C. Suhling ◽  
Leonid Fursin

Stress sensors have shown potential to provide “health monitoring” of a wide range of issues related to packaging of integrated circuits, and silicon carbide offers the advantage of much higher temperature sensor operation with application in packaged high-voltage, high-power SiC devices as well as both automotive and aerospace systems, geothermal plants, and deep well drilling, to name a few. This paper discusses the theory and uniaxial calibration of resistive stress sensors on 4H silicon carbide (4H-SiC) and provides new theoretical descriptions for four-element resistor rosettes and van der Pauw (VDP) stress sensors. The results delineate the similarities and differences relative to those on (100) silicon: resistors on the silicon face of 4H-SiC respond to only four of the six components of the stress state; a four-element rosette design exists for measuring the in-plane stress components; two stress quantities can be measured in a temperature compensated manner. In contrast to silicon, only one combined coefficient is required for temperature compensated stress measurements. Calibration results from a single VDP device can be used to calculate the basic lateral and transverse piezoresistance coefficients for 4H-SiC material. Experimental results are presented for lateral and transverse piezoresistive coefficients for van der Pauw structures and p- and n-type resistors. The VDP devices exhibit the expected 3.16 times higher stress sensitivity than standard resistor rosettes.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3746 ◽  
Author(s):  
Antonio Lazaro ◽  
Ramon Villarino ◽  
David Girbau

In this article, an overview of recent advances in the field of battery-less near-field communication (NFC) sensors is provided, along with a brief comparison of other short-range radio-frequency identification (RFID) technologies. After reviewing power transfer using NFC, recommendations are made for the practical design of NFC-based tags and NFC readers. A list of commercial NFC integrated circuits with energy-harvesting capabilities is also provided. Finally, a survey of the state of the art in NFC-based sensors is presented, which demonstrates that a wide range of sensors (both chemical and physical) can be used with this technology. Particular interest arose in wearable sensors and cold-chain traceability applications. The availability of low-cost devices and the incorporation of NFC readers into most current mobile phones make NFC technology key to the development of green Internet of Things (IoT) applications.


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2044
Author(s):  
Stanislaw Czapp

In many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in low-voltage power systems is commonly performed with the use of residual current devices (RCDs). In the presence of harmonics, the RCDs may have a tripping current significantly different from that provided for the nominal sinusoidal waveform. Thus, in some cases, protection against electric shock may not be effective. The aim of this paper is to present the result of a wide-range laboratory test of the sensitivity of A-type RCDs in the presence of harmonics. This test has shown that the behavior of RCDs in the presence of harmonics can be varied, including the cases in which the RCD does not react to the distorted earth fault current, as well as cases in which the sensitivity of the RCD is increased. The properties of the main elements of RCDs, including the current sensor, for high-frequency current components are discussed as well.


2019 ◽  
Vol 9 (15) ◽  
pp. 2987
Author(s):  
Moritz Baier ◽  
Axel Schoenau ◽  
Francisco M. Soares ◽  
Martin Schell

Photonic integrated circuits (PICs) play a key role in a wide range of applications. Very often, the performance of PICs depends strongly on the state of polarization of light. Classically, this is regarded as undesirable, but more and more applications emerge that make explicit use of polarization dependence. In either case, the characterization of the polarization properties of a PIC can be a nontrivial task. We present a way of characterizing PICs in terms of their full Müller matrix, yielding a complete picture of their polarization properties. The approach is demonstrated by carrying out measurements of fabricated PICs.


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