Abstract: A system may include a substrate and an array of unit cells for a multi-cell antenna printed on the substrate. Each unit cell may include a first trace having an outer perimeter that forms a cross shape and an inner perimeter that encloses an area within the first trace. Each unit cell may further include a second trace having an outer perimeter that is completely enclosed by and does not contact the inner perimeter of the first trace. Each unit cell may also include a varactor electrically connecting the first trace to the second trace. A method may include receiving an electromagnetic signal at the array of unit cells and controlling a capacitance of the varactor of each unit cell to result in one or more directed beams.

Abstract: A system may include a meta-surface including multiple unit cells arranged along the meta-surface. Structural parameters of each unit cell may vary along the meta-surface. The system may further include at least a first active feed unit directed toward the meta-surface to generate a first beam. The first active feed unit may be configured to move relative to the meta-surface parallel to a 2-dimensional plane. The first beam is steerable by moving the first active feed unit.

Abstract: A system may include a meta-surface including multiple unit cells arranged along the meta-surface. Structural parameters of each unit cell may vary along the meta-surface. The system may further include at least a first active feed unit directed toward the meta-surface to generate a first beam. The first active feed unit may be configured to move relative to the meta-surface parallel to a 2-dimensional plane. The first beam is steerable by moving the first active feed unit.

Abstract: A system may include a radio frequency chain configured to process a signal. The system may further include a reconfigurable antenna including multiple antenna feeds, each of the antenna feeds associated with a beam direction. The system may also include a beam selection network configured to couple the radio frequency chain to a first antenna feed of the multiple antenna feeds to generate a first beam in a first direction, and simultaneously couple the radio frequency chain to a second antenna feed of the multiple antenna feeds to generate a second beam in a second direction.

Abstract: A system may include a radio frequency chain configured to process a signal. The system may further include a reconfigurable antenna including multiple antenna feeds, each of the antenna feeds associated with a beam direction. The system may also include a beam selection network configured to couple the radio frequency chain to a first antenna feed of the multiple antenna feeds to generate a first beam in a first direction, and simultaneously couple the radio frequency chain to a second antenna feed of the multiple antenna feeds to generate a second beam in a second direction.

Abstract: A system may include a radio frequency chain configured to process a signal. The system may further include a reconfigurable antenna including multiple antenna feeds, each of the antenna feeds associated with a beam direction. The system may also include a beam selection network configured to couple the radio frequency chain to a first antenna feed of the multiple antenna feeds to generate a first beam in a first direction, and simultaneously couple the radio frequency chain to a second antenna feed of the multiple antenna feeds to generate a second beam in a second direction.

Abstract: A wireless system, and particularly, a multiple-input multiple-output (MIMO) wireless communication system is disclosed. The wireless system includes a plurality of (re)configurable antennas and a rate-two space coding design for a MIMO system. The MIMO wireless communication system generally includes M (re)configurable antennas configured to independently transmit or broadcast wireless electromagnetic signals having a frequency in the microwave and/or optical ranges, a controller configured to control the (re)configurable antennas, and an encoder configured to encode information onto the wireless electromagnetic signals. The information comprises codewords having N symbols, and the codewords are expressed in an N×M matrix having a non-zero determinant and in which at least one symbol is associated with a coefficient configured to maximize diversity, maximize coding gain and/or reduce channel fading in the MIMO wireless communication system. M and N are each independently an integer of at least 2.

Abstract: An apparatus may include two or more active antenna elements with a corresponding antenna pattern. The apparatus may further include a single radio frequency signal chain communicatively coupled with the two or more active antenna elements. The apparatus may also include multiple passive antenna elements in proximity to the two or more active antenna elements. The multiple passive antenna elements may alter the antenna pattern to form multiple simultaneous beams associated with the two or more active antenna elements.

Abstract: An apparatus may include two or more active antenna elements with a corresponding antenna pattern. The apparatus may further include a single radio frequency signal chain communicatively coupled with the two or more active antenna elements. The apparatus may also include multiple passive antenna elements in proximity to the two or more active antenna elements. The multiple passive antenna elements may alter the antenna pattern to form multiple simultaneous beams associated with the two or more active antenna elements.

Abstract: A wireless system, and particularly, a multiple-input multiple-output (MIMO) wireless communication system is disclosed. The wireless system includes a plurality of (re)configurable antennas and a rate-two space coding design for a MIMO system. The MIMO wireless communication system generally includes M (re)configurable antennas configured to independently transmit or broadcast wireless electromagnetic signals having a frequency in the microwave and/or optical ranges, a controller configured to control the (re)configurable antennas, and an encoder configured to encode information onto the wireless electromagnetic signals. The information comprises codewords having N symbols, and the codewords are expressed in an N×M matrix having a non-zero determinant and in which at least one symbol is associated with a coefficient configured to maximize diversity, maximize coding gain and/or reduce channel fading in the MIMO wireless communication system. M and N are each independently an integer of at least 2.

Abstract: A monitoring system for a valuable item, such as a digital device, has a base unit affixed to the valuable and a remote unit carried by a person responsible for the valuable. Signals are exchanged between the base and remote units. The base continuously monitors for signals from the remote unit and can arm or disarm automatically in response to such signals. When armed, the base communicates with a program running on the valuable to lock peripherals. The base alerts the owner upon movement of the valuable, allowing the owner to screen for false alarms or be notified of an occurring theft attempt. A digital connection between the base and the valuable may be used to encrypt any data stored on the valuable and charge the internal batteries of the security device. A soft switch enables the base to be powered off by the corresponding remote unit.

Abstract: A monitoring system for a valuable item, such as a digital device, has a base unit affixed to the valuable and a remote unit carried by a person responsible for the valuable. Signals are exchanged between the base and remote units. The base continuously monitors for signals from the remote unit and can arm or disarm automatically in response to such signals. When armed, the base communicates with a program running on the valuable to lock peripherals. The base alerts the owner upon movement of the valuable, allowing the owner to screen for false alarms or be notified of an occurring theft attempt. A digital connection between the base and the valuable may be used to encrypt any data stored on the valuable and charge the internal batteries of the security device. A soft switch enables the base to be powered off by the corresponding remote unit.

Abstract: A wireless valuables monitoring device, with proximity sensing and automatic arming and disarming features two way communication between the base unit affixed to the valuable and the remote unit carried by the owner. The base unit continuously monitors the position of the remote unit relative to itself to determine when the owner has left the immediate vicinity of the valuable. The base unit alerts the owner upon disturbance of the protected valuable and allows the user to screen for false alarms and be notified of an occurring theft attempt. A soft power switch enables the base unit to be powered off by the unique remote unit to which it belongs.