All satellites are vulnerable to a wide variety of EMC and environmental effects, from launch to deployment. Of particular concern is the effects of Coronal Mass Ejection (CME) events. These are caused by sun activities that result in waves of cosmic rays and particles and electromagnetic energy. Significant CME events occur in sync with the “11 Year Sunspot Cycle” which, … [Read more...]
Guide to Real-Time Spectrum Analyzers: Types
Introduction The spectrum analyzer is the one “go-to” tool for every RF, microwave, and EMC/EMI engineer. In recent years, a new acquisition technology has developed, based on FFT capture and digital signal processing – the real-time (RT) spectrum analyzer. This series of articles will review the basics of conventional swept versus real-time spectrum analyzers and highlight … [Read more...]
How to Specify Board-Level Shielding
The Purpose of Board Level Shields Board level shields (BLS) are generally small metallic shielded boxes mounted directly to PC board ground return layers. There are three primary purposes of board level shields: Isolation of sensitive circuitry from other noisy circuits on the board Trapping the emissions from noisy circuits on a board from propagating to the outside … [Read more...]
Filter Installation Issues Pt. 2: The Synergy of Filtering and Shielding
This article is part 2 of a three-part Filter Installation Issues series. Read Part 1: Input and Output Conductors here. Some mains filter manufacturers only design and specify their filters to provide attenuation over the frequency range of the conducted emissions tests (typically up to 30MHz for commercial and industrial products), to keep costs low. Unfortunately, if … [Read more...]
Space Weather – Predicting EMC Effects of Solar Storms
When we think about weather, we know what it is. We feel it, worry about it, and talk about the heat, the moisture, the wind. Weather is dynamic, though mostly predictable because we can measure its conditions. We also know that the atmosphere involves large scale electrical activity. Cloud masses move above and below each other, generating enormous static-electricity … [Read more...]
Simultaneous Operations (SIMOPS) of Radio Systems Due to Antenna to Antenna Coupling on an Aircraft
Although specifically dealing with aircraft systems, the methods described in this article are applicable for other platforms where a number of antennas are in close proximity. The number of antennas in use and in close proximity on mission specific aircraft are as many as 22 on a small search and rescue aircraft. ANALYSIS METHODS The methods of coupling analysis include … [Read more...]
Use of Ferrite-Loaded Absorber to Reduce Wireless Self-Interference
Self-generated EMI from DC-DC converters, as well as digital and video processing, has long plagued designers of wireless and IoT devices, especially since physical sizes have trended smaller. The broadband harmonic content often extends up through 1.5 GHz, which includes most wireless protocols, cellular LTE and GPS/GNSS bands. One new mitigation technique I’ve been trying … [Read more...]
5 Ways to Eliminate Ground Loops — Part 2
As we discussed in Part 1, Ground Loops, while often not obvious, can be a significant source of frustration for system operators and integrators. This phenomenon manifests as unwanted electrical noise – audible hums in speakers, jitter on screens, noisy measurements, and bad measurement data – and it can even lead to unexpected communications loss and equipment … [Read more...]
Demystifying the Math of EMC
As we progress through the fold of technological developments, be it in commercial products, military advancements, automotive electronics, or any of the other industries where electromagnetic devices are developed, EMI will be present and EMC testing will be required. For those technical personnel who are walking into a laboratory for the first time, learning EMC because … [Read more...]
Filter Installation Issues: Input and Output Conductors
Real-life filter performance is totally dependant on how they are installed, especially on the impedance of the RF Reference and the impedance of the method used to electrically bond the filter to its RF Reference. Not only should these impedances be much lower than that of the shunt capacitors in the filters, they should also allow the internal and external CM surface currents … [Read more...]
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