Telecommunications electronics materials protected from emanating spurious transmissions (TEMPEST) testing, also called emission security (EMSEC) by the National Security Agency (NSA), is an NSA specification and is defined in the NATO SDIP-27 standard. TEMPEST is designed to deny unauthorized access to information derived from intercepting and analyzing unintended electrical signals, sounds, and vibrations emanating from […]
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Review: Tekbox TBCG4 harmonic comb generator
The Tekbox TBCG4 harmonic comb generator produces a wide range of known frequencies for EMC immunity testing and routine checking of EMC chambers. I’ve used harmonic comb generators for decades in various applications, including antenna measurements, cable resonance measurements, and shielding-effectiveness testing. I also find them useful for checking the daily consistency of test chambers […]
Free and low-cost online EE tools aid in design
Downloadable and online free and low-cost EE tools help engineers design and analyze circuits.
How to calculate and apply an inverse FFT: part 2
In part 1 of this series, we looked at the formula for the inverse discrete Fourier transform and manually calculated the inverse transform for a four-point dataset. Then, we used Excel’s implementation of the inverse fast Fourier transform (IFFT) to verify our work. Could we try something more realistic? Sure. We can take a signal […]
How to calculate and apply an inverse FFT: part 1
The inverse Fourier transform (inverse FFT or iFFT) reverses the operation of the Fourier transform and derives a time-domain representation from a frequency-domain dataset. In early 2024, EE World published a series on the Fourier transform, which can convert a time-domain signal to the frequency domain (Figure 1, red arrow). The process is reversible (Figure […]
How can EMI be weaponized?
Electromagnetic interference (EMI) can be an unwanted and disruptive aspect of electronic system designs. It can also be amplified and weaponized. EMI is being weaponized in purpose-built high-power microwave (HPM) tactical systems that devastate electronics without the side effects of physical destruction. The initial weapons have been deployed, and a roadmap has been outlined for […]
Controlling EMI and improving sustainability
Optimized designs require less electromagnetic interference (EMI) shielding and other materials, improving sustainability. Improved EMI performance extends system life and reduces e-waste, further enhancing sustainability. More sustainable shielding materials are being developed for use when shielding is required. This article reviews the basics of EMI, examines common shielding materials to provide a baseline for comparing […]
Engineers use AI/ML to improve test
Engineers can use AI/ML to reduce test development time, analyze test data from manufacturing, automate visual inspection and calibration, and identify counterfeit components. Here’s how some do it. Testing takes too much time; just ask any engineering or production manager. Shortening test-development time can reduce time to market. Shortening production test time lowers manufacturing costs. […]
How to determine noise figure: part 4
Two incompatible definitions of noise factor can lead to confusion, which you can alleviate by understanding where the differences lie.
How to determine noise figure: part 3
Noise factor and noise figure as defined in an IEEE standard can be derived from a two-port device’s equivalent noise temperature. In part 1 and part 2 of this series we discussed several ways to indicate the noise performance of a device under test (DUT). We first introduced the concept of noise factor based on […]
