Bill Schweber, Freelance Journalist Profile

Articles

Bias Tee: Understanding Its Function in RF Design

4 days ago | eeworldonline.com | Bill Schweber

A conceptually simple passive component is used to combine or split DC and RF signals; however, its implementation has many subtleties. The RF world, operating at hundreds of megahertz and into the gigahertz range, is known for having many unusual components. Some are unique to that higher-frequency world, while others appear at lower frequencies but with different component sizes and physical construction.
2N3904 Transistor: Still Alive and Kicking After 60 Years

1 week ago | ednasia.com | Bill Schweber

Article By : Bill Schweber Here's why design engineers still prefer these tried-and-tested devices to reduce risk, cost, and sourcing hassles. A friend recently sent me an email noting that the classic 2N3904 bipolar transistor was now 60 years old. Since its “birth” was before I got involved with basic electronics, that callout was interesting but didn’t evoke any nostalgic memories on my end.
RF directional couplers shrink in size, not performance: part 2

1 week ago | eeworldonline.com | Bill Schweber

This essential measurement accessory for microwaves has morphed from waveguides down to tiny surface-mount components. Part 1 examines the need for and basic principles of directional couplers and explores some of the construction techniques and implementations. Figure 1 shows the basic arrangement of a single directional coupler. Two parallel transmission lines, each one-quarter wavelength long, correspond to the center frequency of operation.
Evanescence Approach Dramatically Improves Solid-Surface Heat Transfer

1 week ago | eetimes.com | Bill Schweber

Where electronics engineers discover the latest toolsThe design site for hardware software, and firmware engineers eeweb.com Circuit simulation made easy partsim.com Brings you all the tools to tackle projects big and small - combining real-world components with online collaboration schematics.com Hardware design made easy pcbweb.com A free online environment where users can create, edit, and share electrical schematics, or convert between popular file formats like Eagle, Altium, and OrCAD....
RF Directional Couplers: Essential for Engineers

1 week ago | eeworldonline.com | Bill Schweber

This essential measurement accessory for microwaves has morphed from waveguides down to tiny surface-mount components. Engineers who work with circuits typically use a multimeter as their primary test and measurement tool to check voltages and currents. They may also need to assess power with a separate instrument, but this is often secondary.
Tiny Preamplifier Targets Low-Side Current Sensing

1 week ago | electronicdesign.com | Bill Schweber

What you'll learn: Why low-side current sensing is still widely used. Why a precision preamplifier is critical to low-side current-sensing performance. Sensing current flow through a load or from a source is a common, widely needed circuit function.
Why is the 2N3904 transistor still up after 60 years?

2 weeks ago | edn.com | Bill Schweber

In the ever-dynamic and fast-moving world of semiconductors, why do some old transistors like 2N3904 keep on going for decades? Bill Schweber takes a closer look at this remarkable premise while analyzing why design engineers still prefer these tried-and-tested devices to reduce risk, cost, and sourcing hassles. Read the full story at EDN’s sister publication, Planet Analog. Related Content
2N3904: Why use a 60-year-old transistor?

2 weeks ago | planetanalog.com | Bill Schweber

A friend recently sent me an email noting that the classic 2N3904 bipolar transistor was now 60 years old. Since its “birth” was before I got involved with basic electronics, that callout was interesting but didn’t evoke any nostalgic memories on my end. My friend also noted that the 2N3904 transistor was still available as a newly manufactured device (Figure 1).
Wearable bioelectronic skin patches are a busy research area: part 3

2 weeks ago | eeworldonline.com | Bill Schweber

Biomedical skin patches integrating multiple sensing, power, and reporting disciplines are receiving significant R&D effort. This final part concludes with an exposition of three more wearable biometric patches, a technology receiving considerable research attention for many obvious and not-so-obvious reasons. Employing a somewhat different approach, a group at the California Institute of Technology (Caltech) has developed a multimodal sensor that targets assessing an individual’s stress levels.
Do you use low-side current sensing?

2 weeks ago | edn.com | Bill Schweber

Sensing of current going to a load is a critical and often mandatory requirement in many designs. While there are many contact and non-contact ways to accomplish this sensing, such as using Hall-effect devices, current transformers (for AC only, of course), Rogowski coils, fluxgate sensors, among others, the in-line resistor is among the most popular due to its small size, low cost, and overall convenience.