Sound is an analog or linear phenomenon. Traditional audio amplifiers such as Class A and Class AB operate the amplifying transistors in the linear mode. Class A and AB amplifiers can provide clean sound, but are inefficient, like linear power supplies. Class D amplifiers are similar to switched-mode power supplies and use various pulse modulation […]
FAQ
The microstrip antenna, Part 2: Implementation
The microstrip antenna is a convenient, planar, easy-to-fabricate antenna with some attractive attributes and features, as well as some distinct limitations. Part 1 of this FAQ was a brief review of antennas and introduced to microstrip antenna design. This part continues that exploration along with related issues. Q: What’s the difference, if any, between a […]
End-to-end automation is the next leap forward for DFT
by Jay Jahangiri, Product Manager for Mentor, a Siemens Business, Tessent product family The increase in IC design size and complexity adds a number of new challenges to the design flow, including design-for-test (DFT). One of the most successful changes in design-for-test (DFT) flows in recent years has been the deployment of hierarchical DFT. For […]
What is signal attenuation?
Many use the term “attenuation” without completely understanding it. The term is used in several areas, including medical, audio, and even attenuation terminology associated with brewing beer. Generally speaking, attenuation means “lessening” the thing that’s being attenuated. For example, sunglasses attenuate the sunlight reaching your eyes. Attenuating an electrical signal can mean that the act […]
Integrating absolute encoders – An overview of SPI, RS-485, and SSI protocols
Opportunities for electrically-propelled autonomous mobility and advanced automation continue to multiply in the quest for greater industrial productivity, smarter living, and increased energy efficiency. Encoders can play a large part in these applications as motors require precisely tracked position and motion. However, with multiple encoder types and communication protocols on the market, what are the […]
Vacuum tubes we still (have to) use: The traveling wave tube, Part 1
The previous parts of this article explored the photomultiplier tube (Part 1 and Part 2), which is based on a simple, fairly clear physics principle, although building a high-performance PMT is an art and requires various skills, of course. This part looks at a microwave/mm-wave amplifier called the traveling wave tube (TWT – often pronounced […]
Vacuum tubes we still (have to) use: The traveling wave tube, Part 2
We live in a world of solid-state active devices that have made most vacuum tubes obsolete, but a few types remain as they are still indispensable. The previous part of this article introduced the traveling wave tube and its basic operation, along with some attributes. This part delves into some related issues. Q: What’s the […]
Vacuum tubes we still (have to) use: The photomultiplier tube, Part 2
We live in a world of solid-state active devices that have made most vacuum tubes obsolete, but a few types remain as they are still indispensable. Part 1 of this article explained the basics of the photomultiplier tube. This part looks into other PMT characteristics. Q: Are there solid-state functional equivalents to the PMT? A: […]
Vacuum tubes we still (have to) use: The photomultiplier tube, Part 1
Maybe we can’t live with them, but we can’t live without them, at least not yet: the photomultiplier tube and the traveling wave tube are two vacuum electron-tube devices that are still viable and needed in our solid-state world.) It’s widely accepted conventional wisdom that almost “everything” has gone solid state and that vacuum tubes […]
What are the applications and measurements of S-parameters? Part 2
Part 1 of this FAQ was a basic introduction to the context and concept of S-parameters. Part 2 looks at their measurement, application, and relationship to the time domain. Q: How do you actually measure S-parameters? A: In general, except for approximate measurements, you cannot use a spectrum analyzer alone for this frequency-domain test. Instead, […]