The disclosure concerns wireless communication systems, including antenna systems and related methods, which are each directed to utilizing one or more multi-mode antennas for the purpose of varying a radiation pattern characteristic thereof to enhance network security and communication link between an access point and one or more client devices on a network.

Mechanisms for wireless directional transmission systems are proposed. In a first novel aspect, a mechanism for reference signal provisioning and channel information reporting is proposed. Two sets of measurement pilots are introduced for initial access and control signaling. In a second novel aspect, a beamwidth adaptation mechanism is proposed to deal with occasional channel variation without requiring constantly high overhead due to measurement pilot transmission. In a third novel aspect, a mechanism for backhaul link to activate/deactivate efficiently is proposed. New states of activated state and deactivated state are introduced.

A method for suppressing a spurious signal in a payload signal supplied by a receiving antenna of a payload of a satellite. The satellite also includes an array of measurement antennas supplying measurement signals. The measurement signals are combined with the payload signal. Reference weighting coefficients for weighting the measurement signals are determined as a function of the combined signals. A reference beam is formed by combining the measurement signals weighted based on the reference weighting coefficients. Anti jamming weighting coefficients for weighting the payload signal and the reference beam are determined. An anti jammed beam is formed by combining the payload signal and the reference beam weighed based on the corresponding anti jamming weighting coefficients.

A radar apparatus includes: a transmission unit including a plurality of transmission antennas which are arranged at a predetermined transmission antenna interval, and configured to radiate a transmission signal using the plurality of transmission antennas; a reception unit including a plurality of reception antennas which are arranged at a predetermined reception antenna interval, and configured to receive a reception signal when the transmission signal is reflected by an object, through the plurality of reception antennas; and a signal processing unit configured to detect the object based on the reception signal received by the reception unit.

A smart passive RFID reader includes an RFID reader, a microcontroller providing a means for increasing the probability of detecting correct passive RFID tags and decreasing the probability of detecting incorrect passive RFID tags, and antennas connected to the RFID reader, wherein adjacent antennas have orthogonal polarization and the antennas each have a pivoting axis, whereby rotating the antennas about their pivoting axes causes a change in the overlap of the antenna beam radiation patterns and thereby provides a means for adaptive beamforming in order to improve tag reading.

Described embodiments provide sidelobe cancellation for Simultaneous Transmit and Receive systems. The sidelobe cancellation system includes an array having a primary aperture and an auxiliary array. The auxiliary array includes a plurality of antenna elements disposed adjacent to at least one side of the primary aperture. Each element of the auxiliary array is coupled to a variable attenuator, a variable phase shifter or a variable true time delay unit. A controller tunes the auxiliary array to cancel sidelobes of the primary aperture by adaptively selecting an attenuation value of the variable attenuator, a phase shift value of the variable phase shifter and a time delay value of the variable true time delay unit for each element of the auxiliary array. The auxiliary array operates as an adaptive finite-impulse response (FIR) filter with each antenna element of the auxiliary array operating as an adaptive tap of the adaptive FIR filter.

Systems and methods are provided for determining a direction of a signal received at an antenna array. An antenna array includes a plurality of antenna elements, including a reference element. A signal combiner element is configured to combine weighted signals from a subset of the plurality of antenna elements to provide a composite output. An adaptive processing component is configured to determine an optimal set of weights for the subset of the plurality of antenna elements. An angle of arrival search component is configured to find a direction of minimum gain given the optimal set of weights.

In one embodiment, a networking device comprises a first plurality of antenna means, a second plurality of antenna means, and means for controlling the first and second pluralities of antenna means to direct a communication towards a neighbor node of the device.

A smart passive RFID reader includes an RFID reader module, a microcontroller providing a means for increasing the probability of detecting correct passive RFID tags and decreasing the probability of detecting incorrect passive RFID tags, and antennas connected to the RFID reader module, wherein adjacent antennas have orthogonal polarization and the antennas each have a pivoting axis, whereby rotating the antennas about their pivoting axes causes a change in the overlap of the antenna beam radiation patterns and thereby provides a means for adaptive beamforming in order to improve tag reading.

Disclosed is an array antenna comprising a plurality of array elements. The plurality of array elements are formed as a coupler including a central element and peripheral elements configured to surround the central element; each of the central element and the peripheral elements is formed as a waveguide; and the peripheral elements are excited in higher-order modes using coupling slots to form a beam pattern through an electric field distribution of the central element and the peripheral elements.