An analytical model which predicts the attenuation of ultrawide-band (UWB) signals as they traverse various inhomogeneous tissues is presented. The model provides a computationally efficient method of determining the frequency-dependent losses encountered by electromagnetic radio frequency (RF) signals used to communicate with biomedical implants. Classic transmission line theory is employed to...

The technique used to spot information in Magnetic Resonance Imaging (MRI) uses electromagnetic fields. Even minor perturbations of these magnetic fields can disturb the imaging process and may render clinical images inaccurate or useless. Modelling and numerical simulation of the effects of static field inhomogeneities are now well established. Less attention has been paid to mathematical mode...

Atom-based radio-frequency (rf) electromagnetic field sensing using atomic Rydberg states is a promising technique that has recently attracted significant interest. Its unique advantages, such as extraordinary bandwidth, self-calibration, and all-dielectric sensors, are tangible improvement over antenna-based methods in applications test measurement development of broad-bandwidth receivers. Her...

Magnetic resonance imaging (MRI) has become an important diagnostic tool with an ongoing dynamic development towards application of increasing static magnetic flux densities and consequently, exposures to electromagnetic fields (EMF) of increasing radio frequencies (RF). This raises particular concern metallic implants could lead to excess tissue heating and consequently, to thermal tissue dama...

PIN diodes are commonly used to design reconfigurable antennas owing their sufficient isolation, lower cost, and ease of fabrication. This study aims explore the effect biasing conditions a diode radio frequency (RF) switch on frequency-reconfigurable antenna. approach investigates contribution forward current reversed biased voltage shift in operating band, impedance matching, radiation effici...

The possible risks of radio-frequency electromagnetic fields for the human body is a growing concern for our society. We have previously shown that weak pulsed microwaves give rise to a significant leakage of albumin through the blood-brain barrier. In this study we investigated whether a pathologic leakage across the blood-brain barrier might be combined with damage to the neurons. Three group...

Visually-assisted optical indoor wireless local area network (LAN) is promising not only for high-speed but for offering intuitive user interface. Free-space optical communications (FSOC)(Jahns, 1994) are a key technology to create image-based ultra-fast wireless communication systems of the future. Compared with radio-frequency (RF) electromagnetic waves, the outstanding features of free-space...

[1] Analytical and numerical models of the radio frequency emissions produced by relativistic runaway electron avalanches initiated by cosmic ray extensive air showers are presented. It is found that single-point measurements of the distant electromagnetic fields allow the remote determination of the electrostatic field in the runaway electron avalanche region. For instance, it is possible to u...