Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Please note that all times are shown in the time zone of the conference. The current conference time is: 29th June 2025, 08:03:29am CEST
Attenuation of Common-Mode Currents: Skin Effect and Proximity Effect Optimized Absorptive Low-Pass Filter Layer
Matthias Hampe, Mario Potschatski, Sean-Patrik Cretti
Ostfalia University of Applied Sciences, Germany
The attenuation of common-mode (CM) currents, insofar as their generation itself cannot be avoided, is one of the most fundamental tasks in Electromagnetic Compatibility (EMC). Particularly, CM currents can lead to considerable radiated and conducted emissions. Here, the use of magnetic cores has proven to be effective. However, established EMC measures usually have disadvantages in terms of costs, space, weight as well as practical implementability. As a potentially superior alternative, a new type of absorptive low-pass CM filter layer is investigated in this work. Extensive 3D full-wave simulations of a simple multi-conductor arrangement are being performed in order to optimize the CM surface resistance based on the skin as well as proximity effect, without unduly affecting the differential mode (DM). The initial results are promising. A patent is currently pending.
Analysis and Circuit Modeling of Mode Conversion in Non-Ideal EMI Filters
The performance of electromagnetic interference (EMI) filters is often degraded due to mode conversion, which can arise from imbalance due to the non-idealities of the filters themselves. To quantify and address this issue, this paper presents circuit models of EMI filters in the modal domain, including parasitics. The analysis is therefore developed entirely in the modal domain, where mode conversion contributions are represented by induced controlled sources. The models not only illustrate how small imbalances lead to unwanted common mode and differential mode noise, but also provide a physical interpretation for mode conversion at circuit level. The accuracy of the models is validated by comparison with traditional analysis in the SPICE solver. Finally, a statistical analysis is conducted to assess the impact of tolerances of real filter components on mode conversion.
A Tunable Decoupling Network for Common-Mode Noise Reduction in High-Speed Connectors
Chih-Yu Fang1, Bin-Chyi Tseng2, Jackson Yen2, Tzong-Lin Wu1
This paper introduces a tunable decoupling network (DN) designed to mitigate radio frequency interference (RFI) from high-speed connectors. The DN incorporates two different couplers, a phase shifter, and an attenuator to suppress common-mode (CM) noise that may interfere with nearby antennas. Signal flow graph analysis was employed to derive the design equations for achieving CM noise cancellation. A practical implementation of the DN demonstrates its effectiveness, and the measurement results of the DN show 14 dB of CM noise suppression at 2.5 GHz. While a USB Type-A connector is used as demonstration in this paper, the principle of this DN is broadly applicable to various connector types.
Electrically Tunable Capacitor for EMC Band-Stop Filters
Timo van Rossen1, Ivan Struzhko1, Tom Hartman1, Frank Leferink1,2
1University of Twente, Netherlands, The; 2Thales Nederland, Netherlands, The
Band-stop filters are sometimes used to replace bulky low-pass filters in specific applications, particularly with frequencies up to 150 kHz. The use of a tunable capacitor could greatly improve the performance of such band-stop filters, by tuning its resonant frequency. Tunable capacitors are widely utilized in radio-communication systems but are therefore designed specifically for high-frequency and low-power applications. However, the use of these specific components for EMC applications below 150 kHz is not possible since it focuses on low-frequency and high-power systems. Multilayer ceramic capacitors could be well suited for such applications because they can provide high capacitance values, high voltage ratings, and exhibit significant reduction in capacitance when a DC bias voltage is applied. This generally unwanted capacitor property will be explored in this study for its potency to influence the resonance frequency of a tunable band-stop filter. The capacitors showed a reduction in capacitance of up to 70 % using a bias voltage ranging from 0 V to 40 V. This reduction in capacitance allowed the band-stop filter to achieve a resonance frequency ranging from 87 kHz to 134 kHz with attenuation from 17 dB to 23 dB.
An Automated Tool for Modelling Impedance for SPICE (ATMIS) with Focus on DC-Bias Dependent Behavioural Passive Component Modelling
Andree Scambor1,2, Christoph Maier1,2, Michael Fuchs3
1Christian Doppler Laboratory for Technology Guided Electronic Component Design and Characterisation; 2Institute of Microwave and Photonic Engineering, Graz University of Technology; 3edventure Studios GmbH
This work deals with behavioural model generation for current or voltage dependent (DC-biased) passive components, namely inductors and capacitors. Key difficulties for DC-biased model generation are highlighted and a suitable model topology is selected. Also, an automated modelling tool has been developed to generate DC-bias dependent models from measurement data for SPICE-style simulators. Difficulties in the process of automated model generation are highlighted and solutions are proposed. Finally, an application case is presented, utilizing a DC-bias dependent inductor model in a simple time domain switching simulation.
