Dell Products Inc.

Dell & Products L.p.

Tejinder Singh

Navjot Kaur Khaira

Morris Repeta

Davi V Q Rodrigues

Raja Neogi

Raafat Rezk Mansour

Mehran Golcheshmeh

Kan Wang

The technology described herein is directed towards monitoring and maintaining path integrity of a wireless communications path between authorized entities, in which a reconfigurable intelligent surface is part of the signal path between a base station and a user equipment. In one example, an eavesdropping entity intercepts signals to and/or from a base station and user equipment via a reconfigurable intelligent surface. The change in the path integrity from the redirected signals can be detected, e.g., via actual angle of arrival and/or signal strength data that does not match expected angle of arrival and/or expected signal strength; measured versus expected time-of-flight can be used to validate the path. The reconfigurable intelligent surface includes a reconfigurable delay detection network can change capacitance/phase to delay subsequently communicated signals and mitigate the attack. In one implementation, generative adversarial network models are used in the monitoring and correction of the signal path.

Full path integrity correction in a reconfigurable intelligent surface based on compromised path detection

The technology described herein is directed towards a reconfigurable intelligent surface (RIS) that harvests RF energy from incoming signals. In one implementation, there are two types of RIS elements (unit cells), one type engineered to capture and wirelessly harvest energy from incoming electromagnetic waves, while the other type redirects the incoming signals towards a predetermined direction. The harvested energy is combined and converted to DC power using a harvesting circuit. In one implementation, a dual-mode energy harvesting circuit employs a higher power rectifier sub-circuit and a lower power rectifier subcircuit, with a multiport circulator and switch that self-actuates to use one or the other rectifier subcircuit based on the combined RF input power captured by the energy harvesting elements. A multiple battery approach is described, in which one battery is charging based on the converted DC power, another, previously-charged battery is powering the reconfigurable intelligent surface components.

Self-powered autonomous reconfigurable intelligent surfaces using wide radio frequency power range harvesting circuit

The technology described herein is directed towards phase-change material-based (e.g., chalcogenide) radio frequency components that can be used in unit cells of a reconfigurable intelligent surface. A multi-state tunable capacitive element for reconfigurable operation is described, in which phase-change material operates as a switching element to controllably vary capacitance of each unit cell. The multi-state tunable capacitive element can be made of multiple subcircuits in which capacitors of various values can be selectively switched in or out to vary the capacitance of the multi-state tunable capacitive element, resulting in a phase change of a unit cell with respect to reflecting or refracting an electromagnetic wave. By arranging the subcircuits with capacitors of different values, and actuating each one in or out of the overall capacitive element, an analog-like variable capacitor is provided to provide more granular phase shift control of cells of a reconfigurable intelligent surface.

Precise multi-state tuning for changing resistance states of reconfigurable intelligent surface utilizing advanced materials

The technology described herein is directed towards a capacitor with a modified design (relative to standard capacitors), in which a first conductor is coupled to a second conductor via a distributed array of conducting interconnects through a dielectric that separates the conductors. The array of interconnects can be geometrically distributed. The array of conducting interconnects, not present in standard capacitors, results in capacitors with larger self-resonant frequency, e.g., having a substantially stable capacitance over a range of high radio frequencies, e.g., from one gigahertz to twenty gigahertz. This further provides an improved quality factor. The improvements resulting from the array of interconnects, facilitates more optimal surface current density. The modified capacitor provides benefits in various circuits, e.g., in a tuning element as part of an impedance matching network, in a millimeter wave frequency phase shifter for antenna elements, and so on.

Capacitor with array of interconnects for improved self-resonant frequency and quality factor

The technology described herein is directed towards a multiband unit cell that is part of a reflective surface that can reflect different specific frequencies of impinging electromagnetic waves. The unit cells can have different phase profiles to facilitate beam steering and/or beam splitting functionality, independently for each specific frequency. The multiband unit cell can be a dual-band unit cell based on a straightforward unit-cell design, e.g., using diagonally arranged ring resonators as sub-cells of a supercell. Alternative design variations are also described to accommodate multi-frequency (greater than two frequency) applications. In one example implementation, the metasurface is constructed as a low-profile dual-band reflective surface with beam-steering and/or beam-splitting capabilities, e.g., utilizing only a single unit cell metal layer above a substrate. This enables precise control and manipulation of an antenna's radiation pattern, providing enhanced coverage for both frequency bands while keeping the fabrication/manufacturing costs relatively low.

Multiband reflective surface with beam steering and beam splitting functionality

A magnetless cryogenic circulator is developed that has three identical resonators in three branches. Each branch connects two ports and each resonator has a capacitor connected across a tunable inductor. A set of tunable inductors modulated with modulation signals that have a relative phase of 0°, 120° and 240° provided through a circuit. A microstrip delay line for providing the modulation signal to the three resonators, wherein the resonators are modulated in time such that the degeneracy of the two inherent counter-rotating modes is lifted, achieving a non-reciprocal signal routing. All capacitors and inductors are monolithically integrated and fabricated using a multi-layer Nb-based process with Nb/AlOx/Nb JJs.

Magnetless cryogenic circulator

The technology described herein is directed towards a calibration procedure for remote estimation of the position and orientation of an intelligent reflective surface. The calibration is based on accurate estimation of the relative distances between each element of an intelligent reflective surface and a transmission-reception point, e.g., radar sensor, wireless access point and/or base station. A multifrequency (e.g., dual-tone) calibration signal is transmitted to selected elements of the intelligent reflective surface, with the returned calibration signals used to determine the distance to each selected element, from which distances to other elements are determined, along with the intelligent reflective surface's orientation. An active backscatter tag that boosts the returned signal improves the distance measurement accuracy. From the data obtained, the phase delays along the path linking a target and any element of the intelligent reflective surface, and the path linking that element and the transmission-reception point can be directly determined.

Calibration procedure for accurate positioning of intelligent reflective surfaces

The technology described herein is directed towards phase-change material-based (e.g., chalcogenide) radio frequency components including for use in unit cells of a reconfigurable intelligent surface. A multi-state tunable capacitive element for reconfigurable operation is described, in which phase-change material operates as a switching element to controllably vary capacitance of each unit cell. The multi-state tunable capacitive element can be made of multiple subcircuits in which capacitors of various values can be selectively switched in or out to vary the capacitance of the tunable capacitive element. Arranging the subcircuits with capacitors of different values, and actuating each one in or out of the overall capacitive element, an analog-like variable capacitor is realized that provides more granular phase shift control of cells of a reconfigurable intelligent surface. When used with a dual split ring resonator capacitor, phase changes of a unit cell are achieved that redirect electromagnetic waves of two different frequencies.

Chalcogenides-based dual-band tuning for changing resistance states of reconfigurable intelligent surfaces of devices

The technology described herein is directed towards a wearable device that includes a passive metasurface of unit cells with a segmented ground plane of electrically separated segments. When the wearable device is worn, e.g., as a ring or wristband that contacts the wearer's skin, the wearer's skin conductivity electrically connects the separated segments to provide a ground plane. With a complete ground plane, the metasurface's unit cells resonate when exposed to a transmitted signal and reflect a distinct signature corresponding to a physical radiation pattern of signals reflected by the activated metasurface. When not worn, the metasurface is deactivated because of the electrically disconnected ground plane segments. Thus, when a transceiver transmits a wireless radio frequency signal towards an activated metasurface, the radiation pattern of the reflected signal is distinct per metasurface, providing a signature of that particular metasurface, which can be used for proximity detection and/or authentication, for example.

Activation and deactivation detection for a passive wearable metasurface using a segmented ground plane

One example method includes receiving inputs (1) specifying a total power amount for the communication system, (2) specifying communication system operational parameters, and (3) specifying a number of elements implemented in the IRS. Based on the inputs, a portion of the total power amount needed to switch an element of the IRS from a passive element to an active element, an amplification amount of the element, and the SNR of the wireless signal received at the receiver when the first element is an active element are calculated for all combinations of elements of the IRS. Based on the calculations, a number of elements implemented in the IRS are selected to switch from passive elements to active elements that will result in a maximum SNR of the wireless signal received at the receiver.

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Kanata, Canada

Tejinder Singh