Abstract: A single-switch-per-bit topology for reconfigurable reflective surfaces (RRSs) is provided. Novel multi-bit unit-cell configurations are presented for radio-frequency (RF) RRSs with improved radiation efficiency and compact designs. Embodiments described herein realize a multi-bit RRS using an antenna array with multiple integrated switches at the ports of every antenna element (e.g., one at each port, providing one control bit per switch). By manipulating the states of the switches, the impinging waves on the surface are modulated, leading to beamforming in the desired direction. Some embodiments utilize a single switch-per-bit topology integrating single-pole-single-throw (SPST) switches (e.g., PIN diodes) into the unit-cell design, achieving up to 4 bits of phase quantization with only 4 switches. The exhibited radiation efficiency of the multi-bit RRS is significantly improved compared to lower bit configurations.

Abstract: Terahertz wave plethysmography provides a new principle of radar-based vital sign detection. This disclosure presents new applications at terahertz (THz) frequency band for non-contact cardiac sensing. For the first time, cardiac pulse information is shown to be simultaneously extracted based on two established principles using unique THz waves. A novel concept of Terahertz-Wave-Plethysmography (TPG) is introduced, which detects blood volume changes in the upper dermis tissue layer by measuring the reflectance of THz waves, similar to the existing remote photoplethysmography (rPPG) principle. A detailed analysis of pulse measurement using THz is provided. The TPG principle is justified by scientific deduction and carefully designed experimental demonstrations. Additionally, pulse measurements from various peripheral body regions of interest (ROIs), including palm, inner elbow, temple, fingertip, and forehead, are demonstrated using a novel ultra-wideband (UWB) THz sensing system.

Abstract: A single-switch-per-bit topology for reconfigurable reflective surfaces (RRSs) is provided. Novel multi-bit unit-cell configurations are presented for radio-frequency (RF) RRSs with improved radiation efficiency and compact designs. Embodiments described herein realize a multi-bit RRS using an antenna array with multiple integrated switches at the ports of every antenna element (e.g., one at each port, providing one control bit per switch). By manipulating the states of the switches, the impinging waves on the surface are modulated, leading to beamforming in the desired direction. Some embodiments utilize a single switch-per-bit topology integrating single-pole-single-throw (SPST) switches (e.g., PIN diodes) into the unit-cell design, achieving up to 4 bits of phase quantization with only 4 switches. The exhibited radiation efficiency of the multi-bit RRS is significantly improved compared to lower bit configurations.

Abstract: Mapping and localization using image processing of wireless signals is provided. Embodiments of the present disclosure provide a novel approach for high accuracy mapping of an environment around an antenna (or antenna array) coupled to a radio frequency (RF) transceiver through image processing of RF signals. The image processing includes constructing a map of line-of-sight (LOS) and non-line-of-sight (NLOS) objects in the environment by distinguishing NLOS objects and correctly projecting their positions relative to the LOS objects. In some examples, a three-dimensional (3D) image of the environment around the antenna (or antenna array) is produced. Aspects disclosed herein can further provide simultaneous localization and mapping (SLAM) for a wireless device.

Abstract: Methods, apparatuses, systems, and implementations of an ultra-compact RF (30 GHz-10 THz) imaging sensor topology that provides a new insight into the human skin are disclosed. The skin tissue is the largest organ in the body—both in weight and surface area—and stores valuable information that can revolutionize security biometrics and mobile health monitoring. The proposed compact sensor enables, for the first time, portable and wearable devices to perform superior biometric authentication compared to current fingerprint methods. Additionally, these devices could probe into the skin to monitor vital signs in real-time and enable mobile health monitoring.

Abstract: Mapping and localization using image processing of wireless signals is provided. Embodiments of the present disclosure provide a novel approach for high accuracy mapping of an environment around an antenna (or antenna array) coupled to a radio frequency (RF) transceiver through image processing of RF signals. The image processing includes constructing a map of line-of-sight (LOS) and non-line-of-sight (NLOS) objects in the environment by distinguishing NLOS objects and correctly projecting their positions relative to the LOS objects. In some examples, a three-dimensional (3D) image of the environment around the antenna (or antenna array) is produced. Aspects disclosed herein can further provide simultaneous localization and mapping (SLAM) for a wireless device.

Abstract: Methods, apparatuses, systems, and implementations of an ultra-compact RF (30 GHz-10 THz) imaging sensor topology that provides a new insight into the human skin are disclosed. The skin tissue is the largest organ in the body—both in weight and surface area—and stores valuable information that can revolutionize security biometrics and mobile health monitoring. The proposed compact sensor enables, for the first time, portable and wearable devices to perform superior biometric authentication compared to current fingerprint methods. Additionally, these devices could probe into the skin to monitor vital signs in real-time and enable mobile health monitoring.

Abstract: A test fixture for characterizing a device-under-test (DUT) includes first and second planar antennas and a planar waveguide arranged to guide terahertz (THz) and/or millimeter wave (mmW) radiation between the first and second planar antennas. The planar waveguide is further configured to couple THz and/or mmW radiation guided between the first and second planar antennas with the DUT. A beam forming apparatus is arranged to transmit a probe THz and/or mmW radiation beam to the first planar antenna of the test fixture. An electronic analyzer is configured to wirelessly receive a THz and/or mmW signal emitted by the second planar antenna responsive to transmission of the probe THz and/or mmW radiation beam to the first planar antenna. The planar antennas may be asymmetrical beam-tilted slot antennas.

Abstract: A test fixture for characterizing a device-under-test (DUT) includes first and second planar antennas and a planar waveguide arranged to guide terahertz (THz) and/or millimeter wave (mmW) radiation between the first and second planar antennas. The planar waveguide is further configured to couple THz and/or mmW radiation guided between the first and second planar antennas with the DUT. A beam forming apparatus is arranged to transmit a probe THz and/or mmW radiation beam to the first planar antenna of the test fixture. An electronic analyzer is configured to wirelessly receive a THz and/or mmW signal emitted by the second planar antenna responsive to transmission of the probe THz and/or mmW radiation beam to the first planar antenna. The planar antennas may be asymmetrical beam-tilted slot antennas.