Abstract: A communication network includes multiple mini-hub terminals for transmitting and receiving information from multiple remote terminals. Some of the multiple mini-hub terminals, and some of the multiple remote terminals are capable of wireless communication respectively with each other through satellite communication means. A co-located terminal is hard wire connected with at least some of the mini-hub terminals. At least some of the terminals includes a flat antenna comprising a ground plane and a substrate forming at least one in flat array antenna mounted relative to the ground plane. The flat array antenna has multiple spaced dipoles formed on the substrate to constitute the array, and a transmission line formed on the substrate connecting the spaced dipoles. The transmission line is for connection with a link to a terminal with which communication is to be affected by signals through the antenna. A mobile antenna has beam steering lenses for forcing the signal.

Abstract: A communication network comprises multiple mini-hub terminals for transmitting and receiving information from multiple remote terminals. Some of the multiple mini-hub terminals, and some of the multiple remote terminals are capable of wireless communication respectively with each other through satellite communication means. A co-located terminal is hard wire connected with at least some of the mini-hub terminals. At least some of the terminals includes a flat antenna comprising a ground plane and a substrate forming at least one in flat array antenna mounted relative to the ground plane. The flat array antenna has multiple spaced dipoles formed on the substrate to constitute the array, and a transmission line formed on the substrate connecting the spaced dipoles. The transmission line is for connection with a link to a terminal with which communication is to be affected by signals through the antenna. A mobile antenna has beam steering lenses for forcing the signal.

Abstract: A flush mounting, cavity-backed, dual orthogonal slot antenna in which improved radiation pattern characteristics are obtained by making the spiral slot pattern elliptical in the aperture plane. A cavity (11) and a flanged aperture plate (11a) are shown in which one slot pair (12 and 13) is orthogonal with respect to another slot pair (14 and 15) within the aperture plate (11a). Coaxial split-tube baluns (12a and 14a) are used to drive the junctions between corresponding slot pairs. Optional cavity dielectric (18) is provided and a drive coupling arrangement includes a four port comparator hybrid (30) having .ltoreq. and .DELTA. ports (17 and 16) respectively, for alternate excitation to produce a single lobe or a double lobe pattern with null. Switching apparatus is provided to connect a common terminal (26) to either of the ports (17 or 16).

Abstract: A flush-mounted antenna assembly (10) including a generally rectangular, conductive, box structure (11) open along one face to form a cavity. Within the cavity a pair of mutually orthogonal dielectric plane surfaces (13) (14) in an "egg crate" arrangement are mounted normal to the plane of the open face, each diagonally within the cavity. Each dielectric plane supports a pair of printed circuit dipoles typically (16) each fed from the opposite side of the dielectric plane by a printed "cone-shaped" feed line trace (15) which also serves as an impedance matching device (19) and functions as a balun connected from an unbalanced strip line external feed (24 and 26).The open face of the conductive cavity can be flush mounted with a randome thereover, the assembly thereby being flush with the skin of a aircraft or space vehicle.

Abstract: Disclosed is a coaxial antenna array for communicating circularly polarized electromagnetic radiation. A pair of open ended antenna cavities is coaxially constructed and operates by excitation of linear radiation elements arranged within each of the cavities. A pair of crossed-dipole radiation devices are centered within the inner cavity and operated by means of a phase-shifting network circuit to transmit as well as receive circularly polarized radiation. Four monopole radiation devices are symmetrically arranged to operate in the outer cavity in phase quadrature by means of the phase-shifting network circuit to also both transmit and receive circularly polarized electromagnetic radiation. Combined operation of the two antenna cavities with a 180.degree. phase differential between the fields related to the two antenna cavities provides a broad beam, relatively wide frequency bandwidth communication capability.