Common-mode Noise Suppression Research Articles

Common-mode intensity noise suppression scheme in phase demodulation of 3×3 coupler based on ellipse fitting algorithm

Addressing the issue of light source intensity noise in the phase demodulation scheme of the 3×3 coupler, this paper proposes a common mode intensity noise suppression scheme for differential signals based on the Ellipse Fitting Algorithm (EFA). This scheme employs the EFA to correct the direct current (DC) components of the three interference signals output by the 3×3 coupler. One of the interference signals is selected as a self-reference signal, and the other two interference signals are then subtracted the self-reference signal to obtain differential signals. This effectively eliminates the common-mode intensity noise in the DC components of the interference signals before demodulation, preventing noise from being aliased into the demodulation results. Then, the EFA and ATAN are applied to the two differential signals for signal demodulation. Experimental results show that, compared with the EFA demodulation scheme, the noise floor of the system is reduced by an average of 18 dB, with a maximum reduction of 26 dB to 1.58 μrad/√Hz at 50 kHz, and the total harmonic distortion (THD) is less than 1%.

Design and Fabrication of a novel wideband common mode noise suppression filter using fuzzy interpolation method

This article proposes two new wideband common-mode noise suppression filters based on a defected ground structure. The first design uses the Butterworth equivalent circuit achieving a fractional bandwidth of 117 %. At first, the resonators are arranged next to each other and the equivalent circuit is extracted. Also, samples with different dimensions of resonators are prepared by electromagnetic simulation analysis, and the fuzzy interpolation method is used for estimating the circuit behavior. The ADS software is used to optimize the values of the variables to achieve the desired bandwidth in the schematic environment. This paper utilizes the Taguchi method to strike a balance between various parameters in the filter design, aiming to minimize errors during the fabrication process. Then, the new values estimated with the fuzzy interpolation method are verified by electromagnetic simulation. The fractional bandwidth of the filter increases to 124 %, and noise can be suppressed by more than 10 dB at the center frequency of 21.45 GHz in the range from 8.1 to 34.8 GHz, with a loss of less than 3 dB in the differential lines. A new equivalent circuit is proposed using the first-order Chebyshev model. It is observed that the electromagnetic simulations and circuit modeling have good agreement with the measurements. Moreover, the eye pattern with a speed rate of 21.45 Gb/s is proposed for USB 3.2 and HDMI 2.0 applications.

Design of Ultracompact Gate Driver Integrated With Current Sensor and Commutation Path for a 211-kW Three-Level SiC Aircraft Propulsion Inverter

The aviation industry is increasingly interested in high-efficiency and high-density electric propulsion systems enabled by high-power Silicon Carbide (SiC) modules. However, designing a high-power SiC-based multi-level inverter for aircraft faces several challenges, including high loop inductance, bulky current sensors, high-bandwidth sampling of device current, partial discharge (PD) at high altitudes, and shorter short-circuit withstanding time of SiC MOSFETs. To address these challenges, this paper proposes an ultra-compact multi-functional gate driver that integrates the driving circuit, Rogowski coil current sensor (RCCS), and commutation path for a 211-kW SiC-based three-level (3-L) propulsion inverter. The optimized commutation path and RCCS provide multiple functions, including suppressing overshoot voltage, ultra-fast short-circuit protection, and ac load current sampling. The gate driver’s electric-field can be controlled by PCB-based shielding and shaping to eliminate the PD at high altitudes, thereby improving power density and reducing insulation risk. The paper presents the design methodology of the multi-functional ultra-compact gate-driver and the board-level to system-level common-mode (CM) noise modeling and suppression. The performance of the gate driver is verified on a 211-kW 3-L altitude-ready SiC propulsion inverter system, achieving a power density of 19.5 kW/kg and 7.1 kW/L.

A Compact Broadband Common-Mode Suppression Filter That Integrates Series-Mushroom into Defected Corrugated Reference Plane Structures.

This paper proposes a common-mode noise suppression filter scheme for use in the servers and computer systems of high-speed buses such as SATA Express, HDMI 2.0, USB 3.2, and PCI Express 5.0. The filter uses a novel series-mushroom-defected corrugated reference plane (SMDCRP) structure. The measured results are similar to the full-wave simulation results. In the frequency domain, the measured insertion loss of the SMDCRP structure filter in differential mode (DM) can be kept below -4.838 dB from DC to 32 GHz and can maintain signal integrity characteristics. The common-mode (CM) suppression performance can suppress more than -10 dB from 8.81 GHz to 32.65 GHz. Fractional bandwidth can be increased to 115%, and CM noise can be ameliorated by 55.2%. In the time domain, using eye diagram verification, the filter shows complete differential signal transmission capability and supports a transmission rate of 32 Gb/s for high-speed buses. The SMDCRP structure filter reduces the electromagnetic interference (EMI) problem and meets the quality requirements for the controllers and sensors used in the server and computer systems of high-speed buses.

A Compact Bandwidth and Frequency-Range Reconfigurable CM Filter Using Varactor-Loaded Dual-Slot-Based Defected Ground Structure

A reconfigurable common-mode (CM) filter with a wide tunable bandwidth and frequency-range is proposed in this article. The filter adopts four compact dual-slot-based defected ground structure (DGS) cells to achieve a wide suppression of CM noise. To simplify the design, only one varactor and one dc-blocking capacitance are loaded on one DGS cell directly, which retains the original structure of the DGS cell. A wide continuously adjustable frequency range and bandwidth can be achieved when different voltages are applied to different varactors. A dynamic equivalent circuit model is built to explain the filter's working principle, which is helpful to obtain the filtering characteristics under different varactor parameters quickly and accurately. In order to verify the feasibility of the scheme, a DGS-based filter with an area of 19 mm × 9.2 mm is implemented under the microstrip line. The simulated results show the filter can achieve a continuously tunable CM suppression of frequency range from 1.9 to 7.3 GHz, and a tunable bandwidth using different voltage supplies. Good agreement between full-wave simulation and measured results is observed.

A Novel Wideband Common-Mode Noise Suppression Filter That Combines Mushroom and Defected Corrugated Reference Plane Structures

A novel wideband common-mode (CM) suppression filter is proposed for high-speed transmission. The filter is embedded in 3 10 mm × 10 mm layers of a printed circuit board (PCB) that combines a mushroom structure and a defected corrugated reference plane structure (MDCRP). Using the novel MDCRP structure generates more resonance frequencies in the CM current return path. This generates a wider CM noise suppression performance. We used a simulation method to obtain the best geometric parameters for the MDCRP structure. The experimental results proved that the full-wave simulation results were consistent with the actual measurement results. This novel filter shows good signal integrity according to actual measurements, and the insertion loss can be kept to less than −2.306 dB from DC to 21 GHz in differential mode (DM). The CM noise can be suppressed by over −10 dB from 5.09 GHz to 20.62 GHz. The fractional bandwidth is 120.8%, and the CM noise improves by 64.5%. An eye diagram proves that the filter can support a 20 Gb/s transmission rate with complete differential signal transmission capability. The MDCRP structure filter can support HDMI 2.0, PCI Express 4.0, USB 3.2, and SATA Express. Therefore, the filter meets current computer and server system products’ design needs.

A Compact Sixth-Order Common-Mode Noise Suppression Filter Based on 3-D Integration Technology

Based on three-dimensional (3-D) integration technology, a compact sixth-order common-mode noise suppression filter is proposed according to delay line theory. As the important parts of the filter, the on-chip inductors are established by through-silicon vias (TSVs) and the capacitors are realized by double layer interdigital structure. Compared with other relative literatures, the proposed filter has a minimized size of 0.29×0.32 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (0.0203 × 0.0224 λg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ). And it can suppress the common-mode noise more than 10 dB from 3.8 to 8.6 GHz or more than 20 dB from 4.45 to 7.85 GHz. Meanwhile, the differential signal insertion loss is kept less than 3dB.

Dual-comb fiber laser for stable frequency distribution.

A passive dual-comb laser can generate two optical frequency combs with different repetition frequencies. These repetition differences have high relative stability and mutual coherence through passive common-mode noise suppression without complex tight phase locking from a single-laser cavity. The comb-based frequency distribution requires the dual-comb laser to have a high repetition frequency difference. This paper presents a high repetition frequency difference bidirectional dual-comb fiber laser based on an all-polarization-maintaining cavity configuration and a semiconductor saturable absorption mirror with single polarization output. The proposed comb laser has a standard deviation of 69 Hz and an Allan deviation of 1.17 × 10-7 at τ = 1 s under different repetition frequencies of 12.815 MHz. Moreover, a transmission experiment has been conducted. Owing to the passive common-mode noise rejection capability of dual-comb laser, after passing an 84 km fiber link, the frequency stability of the repetition frequency difference signal is improved by two orders of magnitude than the repetition frequency signal at the receiver side.

Polarization-multiplexed, single-cavity dual-comb fiber laser based on a birefringent crystal and a saturable absorber.

We introduce a calcium carbonate birefringent crystal into an Er-fiber laser mode-locked by a saturable absorber, where dual-comb ultrashort pulses with orthogonal polarization have been obtained. The two ultrashort pulse trains from the laser exhibit polarization contrast ratios of 30 dB and 20 dB, indicating that the dual-comb mode-locking is due to the polarization-multiplexing mechanism. The dual-comb ultrashort pulses have central wavelengths of 1564.41 nm and 1564.51 nm, and pulse durations of 825 fs and 805 fs respectively. The optical spectra and pulse durations of the asynchronous ultrashort pulses are nearly identical, so that the output of the laser could be directly used for dual-comb applications. Besides, the repetition-rate difference of the two mode-locked pulses is 673 Hz, while its drift is only 0.093 Hz within 2 hours' time. The low drift of the repetition-rate difference manifests the single-cavity dual-comb Er-fiber laser has a high stability and high common-mode noise suppression. At last, we have tested the dual-comb fiber laser in a ranging experiment, where clear interferogram signal can be observed. The experimental results prove that this single-cavity dual-comb Er-fiber laser based on the birefringent crystal and saturable absorber can be a potential source for spectroscopy, optical imaging, absolute distance measurement and other dual-comb applications.

A coherent-averaged dual-comb spectrometer based on environment-shared fiber lasers and digital error correction

Dual-comb spectroscopy (DCS) has been an emerging spectrometric technique with high resolution, high sensitivity, broad spectral range and fast acquisition speed. However, it is hard to achieve high long-term stability and high mutual coherence with low system complexity, which hinders the widespread usage in field-deployed applications. In this paper, we demonstrate a simplified free-running dual-comb spectrometer with long-term stability and mode-resolved resolution. Two free-running mode-locked fiber lasers are environment-shared to achieve effective common-mode noise suppression, which enables long-term aliasing-free dual-comb interferograms (IGMs). Post-proposing error correction algorithm is then utilized to recover full mutual coherence and realize coherent averaging. As a result, the transmittance spectra of H13CN and C2H2 gases with high resolution and high signal-to-noise ratio (SNR) can be measured. To the best knowledge of us, this is the first demonstration of coherent-averaged DCS based on environment-shared free-running fiber lasers, which is promising for promoting the dual-comb spectrometer out of the laboratory and realizing field-deployed applications.

Smooth Bend Structures Using Hybrid Compensation for Common-Mode Noise Reduction

The proposed smooth bend structure was implemented with a 150-degree bend to reduce the asymmetrical part of the differential bend and thus prevent mode conversion loss and common-mode noise. The smooth bend structure maintained the differential signal integrity. In addition, we proposed several hybrid compensation methods to enhance common-mode noise suppression and concluded that a smooth bend using the “L-C-L” compensation method offered the best performance. The frequency-domain analysis, from direct current (DC) to 6 GHz, was suppressed below 17.3 dB for the differential to common-mode conversion loss (Scd21) and maintained a differential insertion loss (Sdd21) above 2.18 dB. Furthermore, the 150-degree bend, using the “L-C-L” compensation method, reduced common-mode noise by 48.9% compared with a 150-degree bend structure in the time-domain analysis. The significant advantage of the proposed structure is that it can be easily fabricated using the printed circuit board (PCB) manufacturing process, reducing costs. The measurement results of the proposed design showed good consistency with the simulations. The proposed hybrid compensation structure successfully reduced the undesirable effects caused by asymmetry; as a result, mode conversion suppression was improved, and common-mode noise was reduced.

Improved Balance Technique for Common-Mode Noise Suppression of PCB-Based PFC

Symmetry and cancellation techniques are often employed to suppress common-mode (CM) noises in switching power converters. In addition, shielding technique (Fei <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> , 2018) has been demonstrated effectively to suppress CM noises for isolated converter with PCB-based transformer design. However, for nonisolated converters, such as power-factor correction circuits, none of the techniques mentioned above is deemed applicable or justifiable. Recently, the balance technique has been demonstrated effectively to suppress CM noises up to a point where the parasitic ringing between the inductor and its winding capacitor is observed (Wang <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> , 2007), (Yang, 2018). This article presents an improved balance technique in a PCB-based coupled inductor design that compensates the detrimental effect of the interwinding capacitors. In the given example, CM noise suppression is effective in the frequency range of interest up to 30 MHz. A CM noise model is established to substantiate the measurement results.

Dual-Band High Absorbing and Broadband Suppressing Common-Mode Noise Filter

In this article, a common-mode noise filter with a wideband suppressing and dual-band high absorbing common mode filter, which is called absorptive common-mode filter, is proposed. The filter is constructed by a reflective-type common-mode filter, a phase matching, and an absorber. It is composed of three layers with 14.98 mm × 9.585 mm. The broadband common-mode noise suppression can be achieved by positioning multiple transmission zeros. By using dual-band phase matching and an absorber, the dual-band absorption can be realized. The frequencies are in the range of 2.4 to 2.5 GHz and 5.17 to 5.33 GHz, respectively. The positioning of transmission zeros and absorption points at those frequencies leads to a high absorption efficiency. The simulation result shows that the common-mode suppression, which is below −10 dB, is from 2 to 11 GHz. The fractional bandwidth is 138%. The differential-mode signal keeps integrity in the range from DC to 12 GHz. The absorption efficiencies in the two frequency sections are 97% and 96%, respectively. The experiment results show only slight differences from the simulation results.

Common mode noise suppression control for two‐motor drive systems

AbstractThis paper introduces a pulse‐width modulation (PWM) method for a two‐motor drive system that reduces the propagation of conduction noise to the power supply. This two‐motor drive system consists of two motors with two inverters, each of which is connected to a common DC bus. The proposed method suppresses the common mode voltage ideally to zero by shifting the rise and fall times of the output voltage of each inverter. Our experimental results show that the rise and fall times of the output voltage can be synchronized even when the two inverters are driven at different amplitudes and frequencies. We confirm that the proposed method suppresses the propagation of conduction noise to the power supply.

Mechanical sharing dual-comb fiber laser based on an all-polarization-maintaining cavity configuration.

We present a mechanical sharing, dual-comb fiber laser based on an all-polarization-maintaining cavity configuration and a nonlinear amplifying loop mirror mode-locking mechanism. This simple setup yields dual-optical frequency combs with a high level of mutual coherence without active servo control. We realized a high relative stability with a standard deviation of 0.27 Hz and a relative beat note between the dual-frequency combs with a full-width at half-maximum of ∼50Hz. Dual-frequency combs were found to have high relative stability and mutual coherence owing to passive common-mode noise suppression using a mechanical sharing laser cavity. This laser configuration can significantly simplify dual-comb spectroscopy.

An EMI‐Optimized Transformer for De‐Y Flyback Converter with Low Common‐Mode Noise

Y‐capacitors are widely used in flyback converters to suppress common‐mode (CM) noise to comply with the strict electromagnetic interference (EMI) standards. However, Y‐capacitors increase the leakage current between the primary and secondary side, which is not allowed in the applications with high safety requirements. In this paper, the displacement current models of two conventional De‐Y methods are quantitatively established to analyze their limitations for the flyback converter. Then, a hybrid EMI‐optimized transformer is proposed to improve the limitations. The proposed structure can completely balance the CM noise between the primary and secondary sides, making the flyback converter comply with the EMI standard under the conditions of no Y‐capacitor. Compared with the traditional methods, the proposed method has a better capability for CM noise suppression, higher universality and the same cost. Finally, the simulation and experimental results verify that the CM noise of the new transformer structure decreases about 10 dB compared with that of the conventional one. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Balanced dual-band superconducting filter using square ring loaded resonators with ultra-low insertion loss and common-mode noise suppression

In this paper, a multi-mode square ring loaded resonator (SRLR) comprising a full-wavelength ring resonator and six open stubs is introduced. The resonant characteristics are discussed and analyzed using differential-mode (DM) and common-mode (CM) equivalent circuits. Compared to the conventional design, the proposed SRLR involves two advantageous modifications for high-order balanced structure. First, two pairs of open stubs on the four corners of the ring resonator provide more flexible control of the internal coupling between two SRLR units under DM excitation. In addition, the shorted H-shaped resonator is compact, which makes proposed structure suitable for high-order filter design with desired operating frequency and bandwidth. Second, one pair of open stubs is added to the ring resonator along the horizontally symmetric plane. We found that the proposed SRLR provides more design freedom for CM noise suppression without extra components or defected ground structure. In addition, the proposed SRLR topology structure is folded to avoid large circuit occupation. Based on our analyses, a fourth-order balanced dual-band bandpass filter was designed with two passbands operating at 2.2 GHz and 3.5 GHz with corresponding in-band insertion loss of 0.1 dB and 0.12 dB, respectively. The filter was fabricated using high-temperature superconductor (HTS) YBCO thin films on an MgO substrate. Good agreement between simulated and measured frequency responses was observed, which verifies the proposed structure and design method.

Compact closed‐loop resonator filters with wide spurious free band and extended common‐mode noise suppression

A theoretical analysis is presented for miniaturised filters with an extended stopband and extended common-mode (CM) rejection, using loaded closed-loop resonators. A numerical method is presented to solve the equations extracted from the ideal transmission line model. Selection of critical resonator parameters to minimise filter area while simultaneously maximising the differential-mode (DM) stopband or the CM noise suppression is explored. The trade-off between size, stopband and CM rejection is presented and used to design three filters at 1 GHz, which are designed to verify the proposed concept. First, a differential second-order filter with an extended DM stopband ( dB) up to and extended CM noise suppression ( dB) up to 6.42 is realised to show the parameter trade-offs. Then optimal resonators are used to develop a compact singled-ended filter () with an extended stopband ( dB) up to and the smallest size. Lastly, a second order filter with an optimal extended CM rejection ( dB) up to is presented. Measured results are presented. All three filters stand out compared to other works by exhibiting the smallest footprint relative to the operating frequency.

Методи боротьби з кондуктивною завадоемісією у зворотноходових перетворювачах

Pulsed power supplies of various topologies (return running, forward running, half-bridge and full-bridge converters) generate high-frequency common-mode noise through their high-frequency mode of pulse-width modulation. Electrical and electronic equipment is known to comply with electromagnetic compatibility standards such as CISPR, IEC, EN, FCC. If necessary, to reduce the converter mass, the pulse-width modulation frequency will increase. As a result, the electromagnetic noise of the power source also becomes larger. Therefore, electromagnetic compatibility problems become one of the most difficult to design power supplies.The article presents methods for reducing conducted noise emission, namely the suppression of common-mode noise in switching power supplies. In particular, schematic methods and methods with constructive changes, physical harmonics compensation methods (interleaving), and methods based on special control methods are presented. The structural and compensation approach allows achieving significant results in reducing the level of common-mode noise. The structural approach includes grounding and shielding. The compensation approach includes three methods: the first is the method of mutual compensation of noise sources; the second is the method of quasicompensation of noise sources; the third is the method of active compensation. The conducted simulation confirmed the decrease in the emission of higher harmonics of the input current in the power network.

Tunable balanced liquid crystal phase shifter based on spoof surface plasmon polaritons with common-mode suppression

ABSTRACT In this paper, a novel design approach for microwave tunable balanced phase shifters with the common-mode (CM) suppression is proposed based on the liquid crystal (LC) technology. The proposed tunable balanced liquid crystal phase shifter (LCPS) is designed by the LC-based microstrip differential line with periodical T-shaped stubs, which supports the spoof surface plasmon polaritons (SSPP) mode. Thanks to the slow-wave characteristic induced by the SSPP mode, both tunable phase shifts and figure of merit (FoM) of the balanced LCPS are effectively enhanced. In addition, the defected ground structure based on slotted dumbbell-shaped resonators is also employed in this design and the CM suppression is integrated into tunable balanced phase shifters for the first time. Finally, the corresponding prototype is fabricated and tested to verify the above theoretical analysis. The measured results demonstrate that this proposed tunable balanced LCPS can simultaneously achieve tunable phase shifts with FoM of more than 12.4°/dB and the CM noise suppression of more than 17 dB attenuation from 2.5 to 5.5 GHz.