One aspect of the work-at-home/stay-at-home environment of the past year has been an increased emphasis on podcasts, online meetings, and online video events. That’s why there’s more interest in microphone technology among those interested in producing a higher-quality experience. Here’s a short run-down on microphones and how they are typically measured and quantified. A microphone […]
FAQ
What is second-generation beamforming and digital beamforming?
Beamforming is an established technology for cellular communications and other applications (see the previous article on “What is beamforming?”). Beamforming was initially developed based on various analog signal chain techniques and processes. In general, beamforming combines antenna array elements to direct signals at controlled angles to maximize signal reception at specific receivers. Analog beamforming can […]
Selecting dc-link capacitors for inverters
One key factor: Determining the nuances of how capacitors handle expected ripple currents. Sam G. Parler, Jr., P.E. Cornell Dubilier Examine a dc link capacitor’s ac ripple current and you’ll realize it arises from two main contributors: the incoming current from the energy source and the current drawn by the inverter. Of course, capacitors cannot […]
What is beamforming?
Beamforming is used in various applications, including sensor arrays, radar, biomedicine, WiFi, and wireless communications. It is an active approach that combines antenna array elements to direct signals at specific angles and create constructive interference. In contrast, other signals are subjected to destructive interference to maximize signal transmission and/or reception. Beamforming can improve the spatial […]
What is a “Joule Thief” dc/dc converter?
In some applications, it can be useful to drain almost all of the energy of a single cell battery, well below the voltage where the battery is usually considered fully discharged or “dead.” That’s when a Joule Thief dc/dc converter can be attractive. The name implies that the dc/dc converter is stealing Joules of energy […]
What is precoding and what are the benefits?
Precoding involves preprocessing of the transmit signal in an RF system. As described below, precoding uses channel state information at the transmitter to improve performance and increase spectral efficiency. It is used to implement the superposition of multiple beams, including several different data streams of information for spatial multiplexing. Precoding is the transmitter signal processing […]
Maximizing the performance of SiC through gate drive techniques
New gate drivers simplify the task of deploying silicon-carbide FETs to shrink the size and boost the efficiency of power inverters. Charlie Ice Silicon Labs The electric vehicle revolution is upon us. Automotive companies search desperately for a technological edge, investors see EV companies as more valuable than traditional automakers, and governments press ahead with […]
Fundamentals of fast chargers for phones and notebook PCs
Overlapping protocols and competing standards have created a confusing landscape for USB chargers. Here are the important differences and similarities of most interest to designers. Masashi Nogawa, Staff Systems Engineer Qorvo The first standard for charging via USB connections allowed power delivery at a 7.5-W maximum. Recently the USB standard jumped up to support 100 […]
No zapping! How to design safe and reliable wireless charging systems
Smart use of protection components can help give consumers a trouble-free charge. Todd Phillips Littelfuse Inc. The convenience that wireless charging systems provide has made them increasingly popular for use with consumer goods and appliances. But the development of wireless charging devices creates a number of challenges for designers. Most wireless applications are characterized by […]
How to boost output hold-up time in power supplies
Many supplies have outputs that don’t stay up long enough in the event of a power loss. Here are some ways to remedy the problem. TDK-Lambda Americas An ac-dc power supply’s input voltage can be interrupted during circumstances such as a brown out condition or a brief power failure. When this happens, the dc output […]