Abstract: A hybrid coupler for dividing an input electrical signal to produce first and second output electrical signals which are substantially out of phase, the hybrid coupler including an input port for receiving the input electrical signal, and an input line for coupling the input electrical signal to a slotline. The hybrid coupler further includes an output line for coupling the first and second output electrical signals to a first output port and a second output port, respectively. The output line has a junction with the slotline. The hybrid coupler further includes a co-planar waveguide electrically connected to said output line and having a first end and an opposing second end, and defining, at the second end, a sum port configured to divert common mode signals received at said first and second output ports to said second end. The slotline transitions into the first end of the co-planar waveguide.

Abstract: A hybrid coupler (20) for dividing an input electrical signal to produce first and second output electrical signals which are substantially out of phase, the hybrid coupler including: a first port comprising an input port (12) for receiving the input electrical signal; an input line (14) for coupling the input electrical signal to a slotline (18); and an output line (24) for coupling the first and second output electrical signals to, respectively, second and third ports comprising, respectively, a first output port (26) and a second output port (28), the output line (24) having a junction with the slotline (18); wherein the slotline (18) couples the input electrical signal to the junction, and the junction acts as a divider to produce the first and second electrical signals; wherein the hybrid coupler further comprises: an input section including said input line (14) and an output section including said output line (24), and wherein the slotline (18) is terminated at the output section by an output open ci

Abstract: According to the invention there is provided a dipole antenna array including at least one dipole antenna sub-array, wherein the dipole antenna sub-array includes a plurality of co-planar antenna units, each antenna unit including a pair of dipole radiating elements and a balun having an output line for providing output electrical signals to the pair of dipole radiating elements.

Abstract: According to the invention there is provided a balun including: a slotline which is coupled to an input line and an output line, in which at least a portion of the slotline is sandwiched between a first and a second layer of dielectric material.

Abstract: There is disclosed a balun for dividing an input electrical signal to produce first and second output electrical signals which are substantially out of phase, the balun including: an input port for receiving the input electrical signal; an input line for coupling the input electrical signal to a slotline; and an output line for coupling the first and second output electrical signals to, respectively a first output port and a second output port, the output line having a junction with the slotline; wherein the slotline couples the input electrical signal to the junction, and the junction acts as a divider to produce the first and second electrical signals; in which at least one of the input line, slotline and output line has a width and a length wherein the width varies over the length.

Abstract: According to the invention there is provided a dipole antenna array including at least one dipole antenna sub-array, wherein the dipole antenna sub-array includes a plurality of co-planar antenna units, each antenna unit including a pair of dipole radiating elements and a balun having an output line for providing output electrical signals to the pair of dipole radiating elements.

Abstract: A radar or other microwave antenna comprises at least one antenna element, a feed structure for the element extending to the antenna element substantially normally thereto through a dielectric substrate, and characterized in that the dielectric substrate is anisotropic whereby to reduce unwanted common-mode currents in the feed structure. The anisotropy may be provided by elongate conductive elements distributed through the dielectric substrate and aligned with their longitudinal axes parallel to the feed structure.

Abstract: There is disclosed a balun for dividing an input electrical signal to produce first and second output electrical signals which are substantially out of phase, the balun including: an input port for receiving the input electrical signal; an input line for coupling the input electrical signal to a slotline; and an output line for coupling the first and second output electrical signals to, respectively a first output port and a second output port, the output line having a junction with the slotline; wherein the slotline couples the input electrical signal to the junction, and the junction acts as a divider to produce the first and second electrical signals; in which at least one of the input line, slotline and output line has a width and a length wherein the width varies over the length.

Abstract: According to the invention there is provided a balun including: a slotline which is coupled to an input line and an output line, in which at least a portion of the slotline is sandwiched between a first and a second layer of dielectric material.

Abstract: An antenna assembly is disclosed which includes a layered structure having a planar array of antenna elements; and a feed arrangement perpendicular to the antenna elements; the layered structure further having layers over the planar array of antenna elements with holes provided therethrough to allow the feed arrangement to be connected to contacts for the antenna elements. The layered structure may include vias provided such that heat may be applied remotely to the contacts.

Abstract: A power divider/combiner comprising a plurality of transmission lines, each transmission line being in the form of a separate longitudinal component (e.g. a length of coaxial cable), wherein the longitudinal components are arranged such that they are substantially parallel to each other, and such that a side of each longitudinal component is contiguous with a side of at least one other longitudinal component. Each of the transmission lines may be of substantially the same length. The length of a transmission lines may be substantially equal to a quarter of the wavelength of an input signal for the power divider/combiner.

Abstract: A radar or other microwave antenna comprises at least one antenna element, a feed structure for the element extending to the antenna element substantially normally thereto through a dielectric substrate, and characterised in that the dielectric substrate is anisotropic whereby to reduce unwanted common-mode currents in the feed structure. The anisotropy may be provided by elongate conductive elements distributed through the dielectric substrate and aligned with their longitudinal axes parallel to the feed structure.

Abstract: A dipole array assembly, is disclosed which includes a plurality of poles arranged in a two-dimensional array to provide a plurality of dipoles, each pole being shaped such that adjacent edges of neighbouring poles that are from respective neighbouring dipoles are relatively long and relatively close to each other compared to the dimensions of the poles, thereby increasing coupling between different dipoles. A feed arrangement is provided in a plane that is at an angle to the plane of the dipoles wherein one or more baluns are integrated in the feed arrangement. Dual polarised operation can be performed independently between the two polarisations.

Abstract: An antenna assembly is disclosed which includes a layered structure having a planar array of antenna elements; and a feed arrangement perpendicular to the antenna elements; the layered structure further having layers over the planar array of antenna elements with holes provided therethrough to allow the feed arrangement to be connected to contacts for the antenna elements. The layered structure may include vias provided such that heat may be applied remotely to the contacts.

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: Phased array antennas, in particular highly coupled arrays of dipoles having a vertical electrical feed structure. A phased array antenna including a plurality of antenna elements and a plurality of electrical feed structures, wherein each feed structure serves an antenna element and each electrical feed structure is at least partially substantially surrounded by a ferrite element.

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.