Wednesday, June 12, 2019

How Wireless RF and Microwaves Affect the World Around You

NuWaves Engineering, June 12, 2019


Radio wave applications have come a long way since it was first theorized by James Clark Maxwell in his 1873 work “A Treatise on Electricity and Magnetism”, where he laid out mathematical theories showing the potential applications of radio technology. Only fifteen years later, German Physicist Heinrich Hertz became the first person to produce, transmit, and receive electromagnetic waves. At the time, Hertz considered his discoveries to have no practical use, going as far as to say “It’s of no use whatsoever”. One hundred and thirty-one years later, we now know the profound advancement RF and Microwave designs have made across the globe; including some ways you might not have even thought about.

Today nearly all people are interconnected wirelessly, and this evolution has transformed nearly all aspects of our lives. Learning, teaching, communicating, entertainment, healthcare – every industry has been sculpted around wireless RF technologies. Today, all of human knowledge and history rests in the palm of our hands, transmitted via an internet connection from a satellite orbiting one hundred miles above our heads. The depth doesn’t stop there though – each individual satellite must communicate with one another as well as the main controller on the ground. None of this would be possible without the usage of radio wave technologies. Not all uses of wireless RF devices are as grand, though. Conservationists in Africa use radio telemetry to track endangered species in their vast habitats. Hospitals utilize wireless RF to track hundreds of patients’ vital signs at once to allow for faster reaction times when it’s most needed.

Our world has forever been shaped by the pioneering into radio frequencies of the scientists, inventors, and engineers that came before us.

...more

Tuesday, October 23, 2018

The Health and Economical Benefits of Solid-State Cooking

MACOM, October 23, 2018

RFE Diagram.PNGThe ability to generate and amplify RF signals is nothing new – but solid-state RF energy has enormous potential beyond data transmission applications. As companies like MACOM and collaborative organizations such as the RF Energy Alliance (RFEA) continue to pioneer and develop this technology, enabling greater efficiency and control than previously possible with conventional technologies, the full potential of this technology for mass-market applications is beginning to take form.

Microwave cooking is one application that is already being radically transformed with solid-state RF energy, enabling healthier eating and broad economical benefits. Solid-state RF energy transistors generate hyper-accurate, controlled energy fields that are extremely responsive to the controller, resulting in optimal and precise use and distribution of RF energy. This offers benefits unavailable via alternate solutions, including lower-voltage drive, high efficiency, semiconductor-type reliability, a smaller form factor and a solid-state electronics footprint. Perhaps the most compelling benefit is the power-agility and hyper-precision enabled by this technology, yielding even energy distribution, unprecedented process control range and fast adaption to changing load conditions, not to mention a lifespan of more than 10 years.

...more

Thursday, September 13, 2018

Giving voice to the elderly

XMOS, September 13, 2018

Voice-enabled technologies will transform the health and happiness of the elderly.

The UN predicts a 56% rise in the number of people aged 60 years or over, taking us from over 900 million in 2015 to nearly 1.5 billion in 2030.The world’s population is changing. Our demographic is aging. And this could well be the defining issue of our time. An aging population creates a burden on health systems and individual households. Family members, clinicians, and assisted care providers will need a new generation of technology platforms to help them stay informed, coordinated, and most importantly, connected.

The social care system is facing a mountain of challenges and it can’t cope with a sustained upswing in the number of senior people and adults living with chronic illnesses.

Whether living at home or in an assisted facility, help may come from an unexpected source – technology. Speech recognition and voice-enabled devices make technology accessible to all. There’s no need to tap a keyboard or figure out how to work the remote control, you simply talk to the device from across the room. A voice-controlled device can empower a formerly ‘dis-empowered’ user. It can ease pressure on caregivers, becoming a companion and digital assistant. Of course it’s not a replacement for human interaction, but rather a meaningful addition.

...more

Monday, April 9, 2018

Common Mode Overview and Reduction Guide

MTE, April 9, 2018

Understanding the creation, effects, and how to reduce common mode over voltage.

What is Common Mode?

To start off, common mode is bad. Common mode voltage is created by Variable Frequency Drives (VFDs) that serve as a way of controlling the speed of AC motors by varying the frequency of the power source using pulse width modulation (PWM). This is done by switching the transistors, IGBTs, or thyristors, on and off continuously.

The continuous generation of power pulses from VFDs prevents a smooth sinewave from being produced, which at any point is at a sum of zero (see Fig.1). Instead, the waveforms produced result in a sum at any point that is not always zero (see Fig.2). The result is damaging common mode over voltage, which can cause devastating effects to your equipment.

Destructive Effects of Common Mode Over Voltage

Common mode problems occur outside of the VFD, which is why they are difficult to diagnose.  The effects of common mode over voltage are extremely problematic for everyday operations. These problems negatively effect your bottom line, creating the need to replace equipment, increase repair costs, and can result in the loss of production.

...more

Monday, April 3, 2017

Mitigating Phase Noise from Vibration in Air Traffic Control and EW Radar Systems

Trak Microwave, April 3, 2017

Radio Detection and Ranging (RADAR or radar) systems used for air traffic control, targeting, military surveillance and electronic warfare (EW) rely on extremely precise time-domain to frequency-domain conversions. This conversion is either performed with high quality dedicated RF/Microwave hardware, or a blend of digital and RF hardware. This is especially true in the case of modern and complex pulse compression and digitally modulated radar. All radar systems are sensitive to phase noise, but the sensitivity to phase noise is a limiting factor in doppler and pulse compression radar.

One view of phase noise is that of a measure of the spectral purity of a signal, and can be produced by internal effects and external effects. Internal effects are generally in the form of impurities or non-idealities in oscillator circuits and resonators. The most common external effect is that of phase noise due to vibration by certain components and circuits which convert mechanical vibration to phase noise. These components and circuits are considered piezoelectric, and ironically they are usually the resonators, oscillators, and filters which most define the source signal’s frequency and spectral purity in a non-vibrational environment. For radar systems operating in very high vibration environments, the vibration-induced phase noise can be orders of magnitude greater than the static phase noise. Therefore, it is vital to understand the impact that the radar system’s operating environment plays in generating phase noise, and how to mitigate its effects.

There really is no such thing as a radar system operating in a static environment. Even benign environments, such as an office building or a radar installation in a secure facility with mild outdoor weather can experience mechanical and acoustic vibrations responsible for phase noise. Moreover, depending upon the severity, type, and frequency of vibrations, different phase noise producing effects can occur, within an assembly, and around its interconnect.

Essentially, any type of disturbance or perturbation that induces frequency or phase fluctuations produces phase noise. It is important to note, that like the various forms of amplitude noise, phase noise can have distinct narrowband, harmonic, or broadband components. From the highly sensitive crystal oscillator components, to even ruggedized external transmission lines, cables, and connectors, vibrations can produce several forms of noise and phase noise simultaneously.

...more