Modern zero-drift amplifiers provide the extremely low drift and noise performance needed for processing many optical biological, and physical-world signals near 0 Hz. In our world of ever-faster, wider-bandwidth signals and systems operating at higher and higher frequencies, it may seem that signals in the very-low-frequency range — down towards zero hertz (0 Hz) — […]
Minimizing electrical noise to improve medical-ultrasound images, Part 3
Low-noise circuitry is critical to image quality of medical ultrasound, an indispensable diagnostic tool. Efficiency versus noise It may seem that if there is a tradeoff between power-supply noise versus potential efficiency, the need for ultralow noise in the ultrasound application should prevail. After all, a few more tens of milliwatts of dissipation should not […]
Minimizing electrical noise to improve medical-ultrasound images, Part 2
Low-noise circuitry is critical to image quality of medical ultrasound; an indispensable diagnostic tool. Despite the conceptual simplicity of the underlying principle, a complete, high-end ultrasound imaging system is a complicated device (Figure 1). The ultimate performance of the system is largely determined by the transducer and analog front end (AFE), while post-processing of the […]
Minimizing electrical noise to improve medical-ultrasound images, Part 1
Low-noise circuitry is critical to the image quality of medical ultrasound, an indispensable diagnostic tool. Ultrasound technology, a widely used non-invasive tool in medical diagnostics and other applications, has shifted from static to dynamic images and from black-and-white to color Doppler images. These important enhancements are largely due to the introduction of digital ultrasound technology […]
When reality intrudes on component models and equivalent circuits
Determining the utility of an equivalent-circuit model versus construction reality is often a difficult challenge. Using simplified, first-order approximations in models and equivalent circuits is a normal part of engineering life. Without them, we would get mired in the details and harsh reality of the components and their characteristics. We would never be able to […]
What are digital twins, and where are they on the “hype cycle”?: part 2
Digital twins are getting lots of deserved attention, but are they the cure-all for whatever simulation issues you have? Although digital twins are undoubtedly valuable tools along with basic simulation, modeling, HITL, and others, the associated all-good/no drawbacks promotion concerns me. When a tool, product, or other development gets a lot of “pumping up” to […]
What are digital twins, and where are they on the “hype cycle”?: part 1
Digital twins are getting lots of deserved attention, but are they the cure-all for whatever simulation issues you have? Lately, I’m seeing what are called “digital twins” cited everywhere. What is a digital twin? In addition to having that very catchy name, it is a highly advanced model of the system which can be used […]
Confused about RF-band letter designations? That’s not surprising!
Frequency bands within the electromagnetic spectrum have multiple, sometimes confusing, overlapping designations. Electronics engineers must deal with the electromagnetic spectrum as a routine part of their wired and wireless projects. This spectrum of interest ranges from relatively low frequencies in the kilohertz (kHz) range (or perhaps lower) into the tens and even hundreds of gigahertz […]
The why, where, and how of automatic gain control, Part 3
There are many ways to implement the automatic gain control function, which is critical to proper performance of many wireless and other links. The previous parts looked at the AGC in the context of its broadest application of wireless links. This part looks at some other aspects of AGCs. Q: What other applications use AGCs? […]
The why, where, and how of automatic gain control, Part 2
There are many ways to implement the automatic gain control function, critical to proper performance of many wireless and other links. The previous section discussed the context and need for AGC. This section will look at the different ways in which the AGC function is implements, and some of the parameters associated with the AGC […]
