TechBlog

Antennas serve as transducers between electromagnetic waves traveling in free space and guided electromagnetic signals in circuits. As such, they play a critical role in the performance of wireless communication systems. With the proliferation of mobile wireless services that deliver voice and/or data in smaller and smaller devices, the task to design an antenna for a portable unit that meets not only operational requirements but also aesthetic and packaging restrictions is becoming more and more challenging. As result, engineers rely on a combination of theory, simulation, and experimental investigation to arrive at a design that meets all the demands of a particular application.

Basic Antenna Parameters

The basic parameters of antenna are impedence, mismatch and ohmic efficiency, radiation pattern and polarization, directivity, gain and equivalent isotropically radiated power, and effective height and aperture. In addition, celebrated Friis equation is and equations for the signal to noise ratio (SNR) of an antenna and source-field relationships are also important.For a more detailed treatment of the material pointed out here, the reader is referred to “A HANDBOOK OF ANTENNA IN WIRELESS COMMUNICATION” OF CRC Press by Lal Chand Godara.

Continue reading ‘Future Antennas Will be Flat’ »

From Tesla and Marconi’s electric coils and arcs to the youngster’s model car that speeds or stops at the nudge of the controls, we’ve had a fascination with wireless control and communication.

And with the explosion over the last 25 years of wireless from cell phones to Internet, interest in industrial uses has grown. This could easily afflict anyone from refinery or public works managers to manufacturing techs with equipment monitoring and control needs.

Regardless of the potential, early attempts to adapt wireless technology to industrial applications met with limited success.

Continue reading ‘Industrial Wireless Modems Come of Age’ »

Researchers at Children’s Hospital Boston have developed a new “nanobiotechnology” that enables magnetic control of events at the cellular level. They describe the technology, which could lead to finely-tuned but noninvasive treatments for disease, in the January issue of Nature Nanotechnology.

Don Ingber, MD, PhD, and Robert Mannix, PhD, of Children’s program in Vascular Biology, in collaboration with Mara Prentiss, PhD, a physicist at Harvard University, devised a way to get tiny beads — 30 nanometers (billionths of a meter) in diameter — to bind to receptor molecules on the cell surface. When exposed to a magnetic field, the beads themselves become magnets, and pull together through magnetic attraction. This pull drags the cell’s receptors into large clusters, mimicking what happens when drugs or other molecules bind to them. This clustering, in turn, activates the receptors, triggering a cascade of biochemical signals that influence different cell functions.

The technology could lead to non-invasive ways of controlling drug release or physiologic processes such as heart rhythms and muscle contractions, says Ingber, the study’s senior investigator. More importantly, it represents the first time magnetism has been used to harness specific cellular signaling systems normally used by hormones or other natural molecules.

Continue reading ‘An “Attractive” Man-Machine Interface: Researchers Use Magnetic Fields, Rather Than Drugs, To Control Cellular Signaling’ »