When transmitting and receiving electromagnetic signals, there is a need to match the frequencies and the phases of both a received signal and a locally generated signal. In terms of signal to noise ratio (SNR), the alignment of the phases gives the best results for retrieving any data that is modulated on the received signal. Better SNR yields higher...

5G wireless systems are designed to meet the increasing demand for high data rates but face challenges like signal obstruction, poor penetration, high propagation loss, and inadequate scattering. Active relays have emerged as a solution to these issues by re-routing signals to avoid obstructions, ensuring uninterrupted 5G service. However, in dense...

Modern day aircrafts rely on a plethora of communications and navigation systems to enable secure and reliable flight operations. These systems are designed in isolation and physically separated to prevent interference between services. These choices lead to stove-pipe designs that lack backward compatibility. As a direct consequence, exteriors of...

Detecting angle of arrival (AoA) of electromagnetic (EM) signals is a priority for many civil and military applications including navigation, surveillance, and communication systems. The antenna structures typically used for this purpose are required to conform to nearly arbitrary surfaces including robots, cars, aerial vehicles, and missiles. As...

Many navigation systems rely on detecting the angle of arrival (AoA) of waves to determine desired coordinates. For example, a variety of radar systems deploy AoA detection to deliver desired information about the surrounding area or target of interest. Modern radio environments rely on adaptive beamforming techniques to direct electromagnetic waves...

Wireless underground sensing networks (WUSNs) aim to provide real-time remote sensing of soil properties and monitoring of underground activities. Most subterranean animals have already mastered the use of vibrations for underground communication, localization of prey, and detection of predators. Humans, on the other hand, have yet to develop communication...

Orthogonal time frequency space (OTFS) modulation has the potential to enable robust communications in highly mobile scenarios. This is due to multiplexing information-bearing data into nearly-constant channels in the delay-Doppler domain instead of the time-frequency domain, which makes communication more resilient to fast changes in the channel....

Radar systems transmit electromagnetic waves through the air and the objects in the aperture reflect the signal. The reflected signal is captured by the radar to find the position, angle, and velocity of each object. Millimeter-wave (mmWave) radar is a subclass of radar systems that uses millimeter waves to operate. The main advantage of mmWave radars...

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...

Vehicle positioning systems assist operators in travel and operation of air and ground vehicles. For example, aircraft positioning systems assist operators in critical tasks such as landing and takeoff, particularly in low-visibility conditions. Aircraft positioning systems are also key components of remotely controlled tasks such as drone operation....