Heart rate and other cardiac function monitoring is conventionally performed in a healthcare setting utilizing devices such as EKGs and finger pulse oximeters. While effective, this requires physical contact with the patient and a doctor visit, making continuous or long-term monitoring difficult. Microwave radars have been used extensively for...

Background Reflective surfaces, including metasurfaces and reflectarray antennas, are comprised of several subwavelength (< λ/2) passive reflective elements and can steer the reflection of an incident electromagnetic wave in arbitrary directions. Typically, reflective surfaces use one or multiple single-pull-single-through (SPST) switches...

Semiconductor lasers able to emit over the full visible color spectrum have a wide range of practical applications such as solid-state lighting, full-color displays, visible color communications, and multi-color fluorescence sensing. To the human eye, light with a mixture of four monochromatic lasers is visually equivalent to a white illuminant. Current...

Current portable and wearable devices use fingerprint analysis for secure authentication. The fingerprint pattern systems analyze only the surface morphology of the fingerprint, making it easy for hackers to spoof and bypass authentication. RF signals can collect tissue information beyond the surface of the finger and can provide increased security...