Aspects of the disclosed technology relate to an active array system that can form and steer a directed beam across its aperture. The disclosed array system utilizes a novel configuration that significantly reduces a number of transmit and receive elements. In some aspects, the disclosed array system can be configured with a modular design, for example, to permit the extension of the transmit/receive array, e.g., to increase/decrease aperture size. In other aspects, the disclosed array system may be configured to dispose the elements of either the first or second group of radiators in a modular fashion.

An RF receiver may include antenna elements to receive RF signals, and electro-optic modulators to generate corresponding upconverted optical signals by mixing an RF signal with an optical carrier beam. The RF receiver may include a transmission array having a first bundle of optical waveguides that receive and transmit upconverted optical signals from their ends. The ends may be arranged in a first pattern. The RF receiver may include an interference space to receive the upconverted optical signals to form a composite beam, and an array of single mode optical fibers that have lenses positioned in a detection plane to receive a portion of the composite beam. The first pattern of the ends generates an RF emitter interference pattern at the detection plane, and the single mode optical fiber lenses have a geometric arrangement that corresponds to the first RF emitter interference pattern.

Disclosed is a technique that can provide one or more countermeasures against spoofers. A beamformer can control an antenna pattern of a CRPA to generate a survey beam. The survey beam is swept across space to determine a characteristic signature based on carrier-to-noise ratios (C/No) for particular space vehicle signals. Matching C/No signatures can be used to identify the existence of spoofers and invoke a countermeasure, such as nulling.

A communication system utilizing reconfigurable antenna systems is described where beam steering and null forming techniques are incorporated to limit the region or volume available for communication with client devices. The communication system described restricts communication to defined or desired area and degrades signal strength coverage outside of a prescribed region. An algorithm is used to control the antenna system to monitor and control antenna system performance across the service area. This antenna system technique is applicable for use in communication systems such as a Local Area Network (LAN), cellular communication network, and Machine to Machine (M2M).

An apparatus and method for beam steering is disclosed. The apparatus comprises: a beam forming signal generator configured to generate a beam forming signal for applying to at least one of amplitude and phase shift circuitry associated with an antenna array to provide a radiation pattern. A determining means is provided that is configured to determine a signal strength of interfering signals received at the antenna array within a user equipment and to determine a dominant interfering ratio indicative of a strength of a strongest interfering signal relative to a strength of other interfering signals. A comparator is provided that is configured to compare the dominant interfering ratio to a predetermined ratio value and where the dominant interfering ratio exceeds the predetermined ratio value to generate a control signal for controlling the beam forming signal generator to generate a radiation pattern comprising a beam and at least one steered null.

Beamformers and beamforming methods are disclosed which involve diagonal loading (regularization). Features may include the automatic determination of the regularization parameter using a linearly constrained minimum power (LCMP) bounded perturbation regularization (BPR) approach.

An apparatus for mitigating element pattern ripple includes an inner cone, an outer cone, at least one driven element, and at least one director. The outer cone is coupled to the inner cone. The at least one driving element is coupled to the outer cone and is configured to produce at least one primary ray. The at least one director is coupled to the outer cone and is configured to direct the at least one primary ray. The inner cone and the outer cone may be concentric. The at least one driven element may include multiple driven elements. The at least one director may include multiple directors. A number of directors may be equal to a number of driven elements.

A system is described where antenna beam steering techniques are implemented to optimize time and frequency channel resources in wireless communication systems where repeaters are used. Beam steering modes of the antenna systems in the repeaters as well as the nodes are optimized to improve system capacity and load balancing. Client devices in a wireless LAN system can be configured to work as repeaters, with the repeaters containing a beam steering capability. The beam steering capability can be implemented in one or multiple nodes and repeaters in the communication system.

Disclosed is a technique that can provide one or more countermeasures against spoofers. A beamformer can control an antenna pattern of a CRPA to generate a survey beam. The survey beam is swept across space to determine a characteristic signature based on carrier-to-noise ratios (C/No) for particular space vehicle signals. Matching C/No signatures can be used to identify the existence of spoofers and invoke a countermeasure, such as nulling.

An RF receiver may include antenna elements to receive RF signals, and electro-optic modulators to generate corresponding upconverted optical signals by mixing an RF signal with an optical carrier beam. The RF receiver may include a transmission array having a first bundle of optical waveguides that receive and transmit upconverted optical signals from their ends. The ends may be arranged in a first pattern. The RF receiver may include an interference space to receive the upconverted optical signals to form a composite beam, and an array of single mode optical fibers that have lenses positioned in a detection plane to receive a portion of the composite beam. The first pattern of the ends generates an RF emitter interference pattern at the detection plane, and the single mode optical fiber lenses have a geometric arrangement that corresponds to the first RF emitter interference pattern.