Niek Moonen

Unexpected poor performance of presumed high-quality power line filter, and how it improved

A 20 A, 440 V three phase power line filter for a radar transmitter, designed using the best components available and following the correct rules for filter design, showed unexpected poor common mode attenuation levels at frequencies above, already, a few megahertz. Component self-parasitic, as well as mutual component parasitic effects were not the main cause of the poor performance. A redesign using additional capacitors at the input, as well as improving the ground plane, resulted in improvement, but the dominant cause appeared to be the impedance between the ground plane and the reference plane.

Enhanced circuit simulation using mutual coupling parameters obtained via 3D field extraction

Predicting high frequency behavior of systems with equivalent circuit simulations that are including component self-parasitic effects are not sufficiently accurate anymore. Mutual coupling, which is highly dependent on component/traces placement and orientation, has to be included in circuit models. Predicting the impact can be performed using 3D electromagnetic field simulations, but these are complex and time consuming. This paper suggest extracting the mutual coupling parameters from a parametric 3D model. The lumped elements, which represent the mutual coupling via the electromagnetic field, are back-annotated in the equivalent circuit model. Then circuit simulations can be performed very fast and the impact of the mutual coupling can be determined.

Harmonic cancellation in a novel multilevel converter topology for the future smart grid

Increased switching speed of semiconductors are reducing losses, but increasing emissions. EMC compliance becomes increasingly difficult in power electronics. A reactive attitude is unwanted, often due to the possible increased costs of solutions. Converter topologies that can inherently reduce emissions are preferred This paper demonstrates that harmonic cancellation is possible in a novel topology for DC/DC converter applications referred to as the Multi-frequency, Multi-level Modular converter (M3C). The emission spectrum dependency on control parameters is investigated numerically, while measurements on a M3C demonstrator are implemented to verify the occurrence of harmonic cancellation.

Validation of a Fully Anechoic Chamber

This paper describes a technique to characterize the performance of a Fully Anechoic Chamber (FAC) from 500 MHz to 3 GHz based on S-Parameter analysis with antennas and a Vector Network Analyzer (VNA. The measurements have been performed by placing one antenna inside the chamber and performing S11 reflection analyses in the frequency domain. Via Inverse Fast Fourier Transformation (IFFT) the reflections in the time domain have been analyzed. Also, experiments where S21 transmission loss is measured by putting 2 antennas at different locations have been performed. One antenna is omnidirectional while the other is directional and measurements have been performed in the frequency domain using the VNA. The results are transformed to time domain using the IFFT and time gating is applied to identify the direct and reflected signals, resulting in the so-called site-Voltage Standing Wave Ratio (sVSWR). This sVSWR method enables the analysis of the reflected wave, or imperfection of the chamber. The measurement results show that the chamber has good performance.