Abstract: The present invention relates to a vehicle mountable satellite antenna as defined in the claims which is operable while the vehicle is in motion. The satellite antenna of the present invention can be installed on top of (or embedded into) the roof of a vehicle. The antenna is capable of providing high gain and a narrow antenna beam for aiming at a satellite direction and enabling broadband communication to vehicle. The present invention provides a vehicle mounted satellite antenna which has low axial ratio, high efficiency and has low grating lobes gain. The vehicle mounted satellite antenna of the present invention provides two simultaneous polarization states. In one embodiment, an inverted L-shaped waveguide has a first wall extending vertically downward from a top surface. The top surface can include a ridge portion. The top surface includes a plurality of radiating elements for forming a radiating surface.

Abstract: A multi-core DSP device includes a shared program memory to eliminate redundancy and thereby reduce the size and power consumption of the DSP device. Because each of the program cores typically executes the same software program, memory requirements may be reduced by having multiple processor cores share only a single copy of the software. Accordingly, a program memory couples to each of the processor cores by a corresponding instruction bus. Preferably the program memory services two or more instruction requests in each clock cycle. Data is preferably stored in separate memory arrays local to the processor core subsystems and accessible by the processor cores via a dedicated data bus. In one specific implementation, the program memory includes a wrapper that can perform one memory access in the first half of each clock cycle and a second memory access in the second half of each clock cycle.

Abstract: A multi-core DSP device includes a shared program memory to eliminate redundancy and thereby reduce the size and power consumption of the DSP device. Because each of the program cores typically executes the same software program, memory requirements may be reduced by having multiple processor cores share only a single copy of the software. Accordingly, a program memory couples to each of the processor cores by a corresponding instruction bus. Preferably the program memory services two or more instruction requests in each clock cycle. Data is preferably stored in separate memory arrays local to the processor core subsystems and accessible by the processor cores via a dedicated data bus. In one specific implementation, the program memory includes a wrapper that can perform one memory access in the first half of each clock cycle and a second memory access in the second half of each clock cycle.

Abstract: A shunt coupled array of slots in a waveguide broadwall, wherein the slots are defined by a punch operation which leaves a tab connected at one side of the slot. The slot side to which the tabs are connected is alternated. The tabs extend downwardly into the waveguide and provide a means for exciting the slots without requiring the longitudinal slots to be alternatively offset. Thus, the invention provides a method of fabrication which permits elimination of the slot offsets, while at the same time is lower in cost than conventional methods of creating slot openings arrays. Higher antenna gain results from a given aperture when slot offsets are eliminated and the slots are truly located along straight lines in rows and columns.

Abstract: A constant gain sector beam array is obtained by applying equal amplitude, equal phase excitations to a sector array characterized by a curved array geometry. In a simple form, the curve is the arc of a portion of a circle. The radiation pattern can be further enhanced by using a more complex curvature geometry, and by minor adjustments to the amplitudes in the slots. Other forms of shaped beams, such as a cosecant squared antenna pattern, may be obtained by appropriately shaping the curvature geometry.

Abstract: A triplex microwave reflector which includes a primary reflector and a pair of dichroic surfaces disposed between the primary reflector and the focal point of the primary reflector. Each of the dichroic surfaces reflects a specific band of microwave signal frequencies and transmits the others. Microwave signals reflected by one of the dichroic surfaces are focused at a front virtual focal point and microwave signals reflected by the other dichroic surfaces are focussed at a back virtual focal point. Microwave signals transmitted by both the front and back dichroic surfaces are focussed at the primary focal point.

Abstract: An EHF array antenna backplate that integrates thermal cooling structure and signal processing structure together into one unified structure. In one embodiment, forced air is employed to conduct heat from active modules; while in another embodiment, embedded heat pipes are employed. The array backplate is made by using four layers. The layers are: a high density multichip interconnect board, a metal matrix composite motherboard, an integrated waveguide/cavity/cooling structure, and a metal matrix composite baseplate. Each module uses solder bumps to connect to the high density multichip interconnect board where DC power and control logic signal distribution takes place. The modules are soldered in four locations to the metal matrix composite motherboard through openings in the high density multichip interconnect board. EHF signals are coupled to the modules from a resonant cavity via probes that protrude through the high density multichip interconnect board.

Abstract: An array antenna (20) that avoids the generation of grating lobes or second order beams is formed of a two-dimensional array of radiating elements (40) disposed in parallel rows (22) and parallel columns (24), each of the radiating elements being formed as slotted apertures within a top broad wall (28) of a waveguide (26). The width of the broad wall is many times greater than the height of a sidewall (32, 34) of the waveguide, the waveguide having a rectangular cross section. A wave launcher (46) connected to a first end of the waveguide launches a higher-order mode of electromagnetic wave wherein the order of the mode is equal to the number of columns of the radiating elements. A set of vanes (48, 48A) upstanding from a bottom wall (30) of the waveguide extend partway towards the top wall to provide values of inductance and capacitance which resonate at the resonant frequency to inhibit reflection of the electromagnetic wave from individual ones of the vanes.

Abstract: An antenna (20) is formed of a two-dimensional array of radiating apertures disposed in rows (22) and columns (24), each of the radiating apertures being formed as slots (40) within a top broad wall (28) of a waveguide (26). The width of the broad wall is many times greater than the height of a sidewall (32, 34) of the waveguide, the waveguide having a rectangular cross section. A wave launcher (56) connected to a first end wall (36) of the waveguide launches a higher-order mode of electromagnetic wave wherein the order of the mode is equal to the number of columns of the radiating elements. The top wall (28) has an enlarged thickness of approximately one-eighth free-space wavelength. Each of the slots extends via a passage (46) from an input port (48) at an interior surface (52) of the top broad wall to an output port (50) at an exterior surface (54) of the top broad wall. All of the slot output ports are centered at the locations of maximum intensity of electric field.

Abstract: A flat plate array is provided which permits generation of two independent beams from a single slotted waveguide antenna. The two beams are coincident in space, but are of two different linear polarizations, those polarizations being orthogonal, i.e., at right angles to each other. In the preferred embodiment, a plurality of slots are provided in a flat top plate of a waveguide cavity. The slots are located in rows and columns with a predetermined spacing between pairs of slots positioned in the respective rows and columns. Each beam is associated with its own input/output port and either the rows or columns of slots of the array.