The AMB System’s EMI Analysis of Backup Helium Circulator for HTR-10GT

2013 ◽  
Author(s):  
Yan Zhou ◽  
JingJing Zhao ◽  
Ni Mo ◽  
Zhe Sun ◽  
SuYuan Yu
Keyword(s):  
Power Amplifier ◽  
Theoretical Basis ◽  
Current Source ◽  
Voltage Source ◽  
Differential Mode ◽  
Common Mode ◽  
Turn On ◽  
Conducted Emission ◽  
The Common ◽  
Amb System

With the application in HTR-10GT, the reliability and stability of the AMB system should be studied deeply. Especially EMI analysis on the switch power amplifier is needed to be done, since which one is the main interference source for AMB during the switch turn-on and turn-off. Based on it, a simplified and improved modeling method is listed by dividing the nonlinear transition into several stages, and the models of the voltage source and current source are built in the form of the piece-wise linear way. The conducted emission on the differential mode noise and the common mode is shown by simulation. The result could provide the theoretical basis on the designing the grounding, filter and isolation for the AMB system.

Tunable balanced to balanced filtering power divider with high common-mode suppression

Frequenz ◽  
2020 ◽  
Vol 74 (7-8) ◽  
pp. 263-270
Author(s):  
Cao Zeng ◽  
Xue Han Hu ◽  
Feng Wei ◽  
Xiao Wei Shi
Keyword(s):  
Return Loss ◽  
High Selectivity ◽  
Power Divider ◽  
Center Frequency ◽  
Differential Mode ◽  
Common Mode ◽  
Mode Suppression ◽  
The Common ◽  
Equal Power ◽  
Good Agreement

AbstractIn this paper, a tunable balanced-to-balanced in-phase filtering power divider (FPD) is designed, which can realize a two-way equal power division with high selectivity and isolation. A differential-mode (DM) passband with a steep filtering performance is realized by applying microstrip stub-loaded resonators (SLRs). Meanwhile, six varactors are loaded to the SLRs to achieve the center frequency (CF) and bandwidth adjustment, respectively. U-type microstrip lines integrated with stepped impedance slotline resonators are utilized as the differential feedlines, which suppress the common-mode (CM) intrinsically, making the DM responses independent of the CM ones. A tuning center frequency from 3.2 to 3.75 GHz and a fractional bandwidth (12.1–17.6%) with more than 10 dB return loss and less than 2.3 dB insertion loss can be achieved by changing the voltage across the varactors. A good agreement between the simulated and measured results is observed. To the best of authors' knowledge, the proposed balanced-to-balanced tunable FPD is first ever reported.

scholarly journals Bandwidth and Common Mode Optimization for Current and Voltage Sources in Bioimpedance Spectroscopy

2021 ◽  
Vol 12 (1) ◽  
pp. 135-146
Author(s):  
Tobias Menden ◽  
Jascha Matuszczyk ◽  
Steffen Leonhardt ◽  
Marian Walter
Keyword(s):  
Patient Safety ◽  
Current Source ◽  
The Body ◽  
Voltage Source ◽  
Bioimpedance Spectroscopy ◽  
Laboratory Measurements ◽  
Output Impedance ◽  
Frequency Range ◽  
Common Mode ◽  
High Bandwidth

Abstract Bioimpedance measurements use current or voltage sources to inject an excitation signal into the body. These sources require a high bandwidth, typically from 1 kHz to 1 MHz. Besides a low common mode, current limitation is necessary for patient safety. In this paper, we compare a symmetric enhanced Howland current source (EHCS) and a symmetric voltage source (VS) based on a non-inverting amplifier between 1 kHz and 1 MHz. A common mode reduction circuit has been implemented in both sources. The bandwidth of each source was optimized in simulations and achieved a stable output impedance over the whole frequency range. In laboratory measurements, the output impedance of the EHCS had its -3 dB point at 400 kHz. In contrast, the VS reached the +3 dB point at 600 kHz. On average over the observed frequency range, the active common mode compensation achieved a common mode rejection of -57.7 dB and -71.8 dB for the EHCS and VS, respectively. Our modifications to classical EHCS and VS circuits achieved a low common mode signal between 1 kHz and 1 MHz without the addition of complex circuitry, like general impedance converters. As a conclusion we found VSs to be superior to EHCSs for bioimpedance spectroscopy due to the higher bandwidth performance. However, this only applies if the injected current of the VS can be measured.

Fully Differential Class-AB OTA with Improved CMRR

2017 ◽  
Vol 26 (11) ◽  
pp. 1750169 ◽  
Author(s):  
Francesco Centurelli ◽  
Pietro Monsurrò ◽  
Gaetano Parisi ◽  
Pasquale Tommasino ◽  
Alessandro Trifiletti
Keyword(s):  
Cmos Technology ◽  
Current Mirror ◽  
Differential Mode ◽  
Common Mode ◽  
Common Mode Rejection Ratio ◽  
Class Ab ◽  
Fully Differential ◽  
Rejection Ratio ◽  
Mode Behavior ◽  
The Common

This paper presents a fully differential class-AB current mirror OTA that improves the common-mode behavior of a topology that presents very good differential-mode performance but poor common-mode rejection ratio (CMRR). The proposed solution requires a low-current auxiliary circuit driven by the input signal, to compensate the effect of the common-mode input component. Simulations in 40-nm CMOS technology show a net reduction of common-mode gain of more than 90[Formula: see text]dB without affecting the differential-mode behavior; a sample-and-hold amplifier exploiting the proposed amplifier has also been simulated.

scholarly journals A Comprehensive Double-Vector Approach to Alleviate Common-Mode Voltage in Three-Phase Voltage-Source Inverters with a Predictive Control Algorithm

Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 872 ◽  
Author(s):  
Eun-Su Jun ◽  
So-young Park ◽  
Sangshin Kwak
Keyword(s):  
Predictive Control ◽  
Sampling Period ◽  
Voltage Source ◽  
Small Current ◽  
Common Mode ◽  
Voltage Source Inverters ◽  
Common Mode Voltage ◽  
The Common ◽  
Current Ripples ◽  
Vector Approach

In this paper, a comprehensive double-vector approach is proposed to alleviate the common-mode voltage of voltage-source inverters based on a model predictive control scheme. Only six active vectors are selected to alleviate the common-mode voltage. Furthermore, one sampling period must be split to apply two non-zero vectors, which can generate currents with small current ripples and errors, despite not using zero vectors. The developed algorithm regards in full all 36 possible cases combined by two non-zero active vectors when selecting two vectors and splitting them into one sampling period. Thus, an optimal future set of two non-zero active vectors and optimal durations of two non-zero active vectors to produce the smallest current errors between the real currents and the reference in future load current trajectories were selected from 36 entire sets. This was done to minimize the cost function defined at the time when it varies from the first vector to the second vector and at the next sampling instant. Thus, the proposed algorithm can control the output currents with a fast transient response and reduce output-current ripples and errors, as well as alleviate the common-mode voltage to ± V d c / 6 .

Common mode interference reduction in seismic recording

Geophysics ◽  
1982 ◽  
Vol 47 (12) ◽  
pp. 1672-1680 ◽  
Author(s):  
Miles A. Smither ◽  
Arnold Pater
Keyword(s):  
Poor Quality ◽  
Seismic Signals ◽  
Recording Instrument ◽  
Differential Mode ◽  
Notch Filters ◽  
Common Mode ◽  
Interference Reduction ◽  
Seismic Recording ◽  
The Common ◽  
Mode Interference

In spite of the prevalence of high common mode rejection ratio (CMRR) input amplifiers, notch filters are routinely used in seismic recording operations to reduce common mode induced interference. An electrical model of the recording environment which predicts the degradation in system CMRR caused by cable imperfections such as imbalance and leakage is described in this paper. System CMRRs as low as 20 dB can be caused by poor quality cables. A new method of controlling common mode interference has been developed which has none of the disadvantages of notch filters. The method minimizes the correlation between the common mode and differential mode signals at the recording instrument. This process has no effect on the desired seismic signals, has minimal effect on the system noise, and typically results in a system CMRR in excess of 100 dB.

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