Advances in Reverb and Anechoic Chamber Measurements: Half-Day Technical Workshop with Standards Updates and Live Demo

Metrology Aspects of Reverberation Chambers: Theory, Uses, Open Questions, and Current Research

By Ramiro Serra, Associate Professor, EMC Laboratory, Eindhoven University of Technology, The Netherlands

Abstract
Reverberation chambers (RC) are laboratory-controlled electromagnetic environments which can generate statistically uniform fields with known and predictable probability density functions. They are widely used for different electromagnetic compatibility measurements, antenna efficiency estimation, over-the-air tests for wireless systems, and electrical characterization of materials, among other uses and applications. What are the basic principles of operation of RCs? How do you model and predict the distribution of the fields in a RC? How is measurement uncertainty determined in RCs? This extended presentation will provide some basic though fundamental answers to these questions and, hopefully, also trigger a renewed interest for these intriguing and useful chambers.

High-Frequency Emission Considerations for EMC

By Teun van den Biggelaar, Chief Technology Officer, ANTENNEX, Eindhoven, The Netherlands

Abstract
There is a trend for applications (e.g., automotive radar, wireless interconnect, PtMP communication) requiring large bandwidths that can only be found in the millimeter-wave (30-300 GHz) regime. This forces the EMC community to come up with standards and methods that accurately can determine unwanted emissions in an efficient manner. Since the wavelengths gets shorter, but the formfactor of the devices under test more or less stays the same, the emitted radiation can be highly directive. This requires a small angular stepsize, leading to an extreme increase in measurement time as frequency increases. In this presentation, a two-stepped measurement approach will be discussed that focusses on measuring unwanted emissions in a short time span, without sacrificing accuracy.

CISPR and ANSC C63® Overview on Site Validation Measurements from 18 GHz to 40 GHz - Latest Advances in EMC Test Site Evaluation Using Advanced Antenna Measurement Techniques

By Zhong Chen, Chief Engineer, ETS-Lindgren, Cedar Park, Texas, USA

Abstract
This presentation introduces a novel approach for EMC chamber validation beyond 18 GHz, currently under consideration in ANSI C63 and CISPR standards. By integrating Cylindrical Mode Filtered Site Voltage Standing Wave Ratio (CMF SVSWR) with Compressed Sensing (CS), we address inherent challenges in traditional SVSWR methods, such as inconsistency and slow data acquisition. CMF SVSWR utilizes circular path measurements and mode domain post-processing to discern antenna and chamber reflections, crucial for comprehensive VSWR analysis. Compressed Sensing, a data-driven machine learning technique, exploits signal sparsity to reconstruct data from fewer randomly sampled measurement points, thereby reducing test times and eliminating the need for precise turntable positioning.

Cylindrical Mode Filtered SVSWR Demonstration

Following the workshop presentations, Mr. Zhong Chen will conduct a LIVE demonstration in the Kiwa EMC Anechoic test chamber.

Demonstration Abstract
The Cylindrical Mode Filtered SVSWR (CMF SVSWR) is measured by placing the transmit antenna (typically a low gain omni-directional antenna) at the edge of the turntable and performing a single cut vector pattern measurement.  The vector S21 as a function of turntable angle at each frequency is transformed to the spectrum domain, where a filter can be applied to mathematically remove the chamber effects.  The SVSWR is derived by comparing the original pattern in the chamber to the “clean” filtered pattern.  This CMF SVSWR provides a more comprehensive evaluation of the EMC chamber quiet zone and can be readily measured without any special positioning fixtures.  The demonstration will show an entire measurement process including the post processing which can be performed in real time.  This new measurement technique is under consideration for the new draft standard ANSI C63.25.3 under development by the ANSC C63® committee for EMC test sites from 18 GHz to 40 GHz.

NOTE: There is no cost to attend this meeting and all IEEE members and guests are welcome!  However, you MUST register in advance in order to secure seating and lunch.