In a satellite dish, as sometimes used to receive internet signals transmitted via satellite, the signal transmitted by a satellite transponder is reflected by and propagated through a circular or rectangular tube, which is part of the feedhorn. This tube, like all waveguides, has dimensions based on the wavelength of the signal. Its purpose is […]
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Hot topic: How to measure plasma in a fusion reactor
The International Thermonuclear Experimental Reactor (ITER) tokamak is an experimental machine designed to harness the energy of fusion. ITER will be the world’s largest tokamak, with a plasma radius of 6.2 m and a plasma volume of 840 m³. The heart of a tokamak is its doughnut-shaped vacuum chamber. Here, under the influence of extreme […]
Visualizing phase relationships in capacitors
The ideal capacitor consists of two conductive plates separated by a thin dielectric layer that separates and insulates the two plates from each other so they have no direct or resistive electrical connection. When voltage is applied across the plates, they store the electrical charge. The capacitor may take many forms. If the plates are […]
Op-amps and their most important parameters
The operational amplifier (op-amp) has been one of the most successful integrated circuits. A type of differential amplifier with high gain, the differential inputs and single output enable this small, inexpensive IC to use negative feedback in a wide variety of applications, in which its gain (hundreds of thousands of times higher than the difference […]
How to measure current and energy use accurately
General-purpose test equipment can have trouble measuring small currents, particularly if they only happen briefly. New specialized instruments go a long way toward solving this problem. Matt Liberty | Jetperch LLC The direct measurement of current is difficult. It’s usually impractical to count individual electrons, so the two primary techniques for measuring current actually measure […]
Remote Communication with USBTMC
Simple connections employing USB can replace more expensive GPIB setups in test instrumentation. Aaron Fernando, B&K Precision Corp. Engineers from a variety of industries use USB and USBTMC (USB Test & Measurement Class) to remotely control test and measurement instruments from a host computer. It is useful to compare USBTMC to the widely used GPIB […]
Testing LVDS devices at the margins with an AWG
Advanced arbitrary waveform generators have simplified the testing associated with communications over low-voltage differential signaling lines. Chris Loberg | Tektronix First introduced in 1994, low-voltage differential signaling (LVDS) has gone on to become widely used in products such as LCD panels, automotive infotainment systems, industrial cameras and machine vision, notebook and tablet computers, communications systems, […]
What’s new in USB Power Delivery 3.0
A new version of the USB spec puts additional demands on testing regimes that wring out power-handling options. David Maliniak | Teledyne LeCroy Since its official debut in 1996, the Universal Serial Bus (USB) protocol has seen numerous revisions spanning three generations of the standard, with USB 4.0 waiting in the wings for later in […]
Test instruments that aid PCB repair tasks
Basic tools such as DMMs and oscilloscopes may be the only test gear needed for small printed circuit board repairs, but it pays to know when automated systems would be a better choice. Alan Lowne | Saelig Co. Inc. PCBs are more complicated to repair today than even a few years ago. Manufacturing mistakes and […]
What you should know about Wi-Fi 6 and the 6-GHz band
While there are still interference issues to be resolved, new specifications for Wi-Fi in the 6-GHz band will bring instantly better wireless performance. Eve Danel | LitePoint Wi-Fi technology turns 20 this year, and it has proven to be successful beyond the wildest expectations. The recent announcement by the FCC to consider allowing 1,200 MHz […]