Frits Buesink

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.

Protection Against Common Mode Currents on Cables Exposed to HIRF or NEMP

Above deck, cables on naval ships are exposed to high-intensity radiated fields and nuclear electromagnetic pulse (NEMP) that may cause conducted interference and generate electromagnetic fields that exceed the immunity levels of commercially available equipment above and below deck. Exposed cables, such as open power plugs or lighting cables, are modeled and characterized both as a monopole antenna perpendicular to the deck and as a transmission line, representing a cable close to the deck. The placement of an illuminated cable close to the deck is a good protection measure for long cables at low frequencies, which includes NEMP protection. The coupled pulse from a high-intensity NEMP illumination is not expected to cause damage on electric installations. It is shown that for exposed cable length of maximum 25 cm and not placed in the line of sight of transmitters above 400 MHz, no additional protection measures are needed.

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.

Reliable systems design using current boundaries

Many years ago, I started my career as an electromagnetic compatibility (EMC) educator. The reason to teach EMC were some irregularities at the company where a fresh crew of young engineers had been assigned to design and build modern 4-layer double- euro sized printed circuit boards (PCBs) using fast digital logic, to save cost and time over the expensive complicated 20+ layer, much smaller company specific PCB versions that were built before. Unfortunately, the logic devices had become much faster than their predecessors and the boards did not work! It turned out that many other companies were facing the same problems: cross-talk and transmission line effects on PCBs made the, originally independent, hardware modules interfere with each other. It was difficult to build the increasingly complex hardware. A true Hardware Crisis. A similar thing had happened to software engineering (SE) two decades earlier: the Software Crisis [1]. It had become increasingly difficult to produce software as the programs became larger. One programmer could no longer solve the problem on his own and many programmers had to work together on the task.

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.