Abstract: A feed module is provided for an array antenna. The feed module comprises a multi-layer printed circuit board (PCB) feed structure for coupling signals between connections to transmitters or receivers and connection points for connecting to antenna elements of the array antenna. The multi-layer PCB feed structure comprises a body portion, incorporating coupling components, and a number of line sections for connecting to elements of the array antenna. The planar layers of the multi-layer PCB are arranged to be mounted substantially perpendicular to a planar array of antenna elements of the array antenna when the feed module is integrated therewith.

Abstract: A method of estimating a state of at least one target. The method includes obtaining at least one target measurement from a first sensor, and applying a Gaussian Process technique to a target measurement to obtain an updated target measurement.

Abstract: A circuit board is provided, and a method for manufacturing the same, suitable for use in high frequency circuits, and comprising a planar pattern of transmission line conductors for linking components formed on or within the circuit board, the transmission line conductors being formed within a corresponding pattern of trenches arranged so that the conductors lie beneath a finished surface of the circuit board which is polished flat to permit one or more cover boards to be bonded thereto.