Abstract: A substrate is provided with a multiplicity of electrically conductive elements, and the elements are interconnected to form an antenna structure for desired application. Either the antenna pattern itself may be altered according to the invention, or one or more feed points may be changed, or all of the above. As such, the electrically conductive elements may be interconnected to change the directionality of the antenna pattern, the gain, the frequency response, or other operational characteristics. The electrically conductive elements may be arranged in the form of an inchoate antenna pattern or regular array. Switches at key points of the structure enable the pattern to be changed dynamically. Such switching may be carried out in real time in accordance with transmissions/reception characteristics, or in advance using simulations associated with the switched elements.

Abstract: A substrate is provided with a multiplicity of electrically conductive elements, and the elements are interconnected to form an antenna structure for desired application. Either the antenna pattern itself may be altered according to the invention, or one or more feed points may be changed, or all of the above. As such, the electrically conductive elements may be interconnected to change the directionality of the antenna pattern, the gain, the frequency response, or other operational characteristics. The electrically conductive elements may be arranged in the form of an inchoate antenna pattern or regular array. Switches at key points of the structure enable the pattern to be changed dynamically. Such switching may be carried out in real time in accordance with transmissions/reception characteristics, or in advance using simulations associated with the switched elements.

Abstract: The relative movement of a receiver and transmitter in a communications system is used to advantage by electronically synthesizing a larger apparent antenna aperture, thereby increasing signal-to-noise ratio. The approach may be used regardless of whether the transmitter is fixed and the user or vehicle is moving, or the user or vehicle is fixed and the transmitter is moving. According to the method, the apparent angle between the receiver and transmitter is determined relative to the direction of movement and used to produce time-delayed replicas of the received signaling stream which are coherently added to synthesize the increased apparent receiver antenna aperture. Since only the receiver is modified according to the invention, existing transmitters and infrastructures can be used without modification. Although some data buffering is required, only a few number of beams need to be synthesized, in contrast to more complex military SAR configurations.

Abstract: An approach to antenna design optimizes gain, beam pattern, polarization response, and other qualities through self-replicating patterns based upon iterative transformations and candidate geometric shapes. In the preferred embodiment Hausdorff structures are used to realize &lgr;n-arbitrary different radiation patterns, including patterns optimized for multiple frequencies. The most preferred approach applies a sequence of different Hutchinson operators to different geometric subsets, thereby achieving patterns which are not only arbitrary in terms of wavelength/frequency, but also permit variable radiation patterns and variable polarization other desirable criteria. In addition to the use of variable scaling, geometric patterns, and the like, multiple structures may be placed within the same spatial footprint to permit reception over more bands.

Abstract: An antenna pattern disposed on a three-dimensional object is used to optimize gain, beam pattern, polarization response, or other qualities despite or independently of physical orientation. In the preferred embodiment a fractal array is used on a polyhedron, though non-fractal and other self-replicating antenna patterns may be generated through the use of additional transformations and candidate geometric shapes to achieve patterns which are not only arbitrary in terms of wavelength/frequency, but also permit variable radiation patterns and variable polarization other desirable criteria. In addition to the use of variable scaling, geometric patterns, and the like, multiple structures may be placed within the same spatial footprint to permit reception over more bands. As an alternative to a fixed pattern with switches used to swap elements or change feed points, a reconfigurable multi-dimensional array may be used having an active area optimized to maximize reception for a desired frequency and/or direction.

Abstract: Broadly, this invention resides in apparatus and methods involving a set of soundfield nulling algorithms providing a localized decrease in sound intensity. Among the benefits of the approach, is that there is little, if any, affect on other important positions such as power or spectral content, insofar as energy is directed to unimportant areas. In the preferred embodiment, two separate algorithms are used, depending upon the frequency range of the acoustic signal. For lower frequencies (for example, less than 300 Hz), the algorithm is based on Cepstral techniques and overtly uses the fact that in an enclosed area, the predominant acoustic influence is in the form of standing waves. At higher frequencies, however, (i.e., 300 Hz and above), the sound is due to free-space propagation. Consequently, single free-space algorithms that are applied across the spectrum have great difficulty in providing useful sound nulls without distortion.

Abstract: The relative movement of a receiver and transmitter in a communications system is used to advantage by electronically synthesizing a larger apparent antenna aperture, thereby increasing signal-to-noise ratio. The approach may be used regardless of whether the transmitter is fixed and the user or vehicle is moving, or the user or vehicle is fixed and the transmitter is moving. According to the method, the apparent angle between the receiver and transmitter is determined relative to the direction of movement and used to produce time-delayed replicas of the received signaling stream which are coherently added to synthesize the increased apparent receiver antenna aperture. Since only the receiver is modified according to the invention, existing transmitters and infrastructures can be used without modification. Significant cost potentials can be realized via economy of scale, due to relatively simple FFT processing.

Abstract: An antenna pattern disposed on a three-dimensional object is used to optimize gain, beam pattern, polarization response, or other qualities despite or independently of physical orientation. In the preferred embodiment a fractal array is used on a polyhedron, though non-fractal and other self-replicating antenna patterns may be generated through the use of additional transformations and candidate geometric shapes to achieve patterns which are not only arbitrary in terms of wavelength/frequency, but also permit variable radiation patterns and variable polarization other desirable criteria. In addition to the use of variable scaling, geometric patterns, and the like, multiple structures may be placed within the same spatial footprint to permit reception over more bands. As an alternative to a fixed pattern with switches used to swap elements or change feed points, a reconfigurable multi-dimensional array may be used having an active area optimized to maximize reception for a desired frequency and/or direction.

Abstract: An approach to antenna design optimizes gain, beam pattern, polarization response, and other qualities through self-replicating patterns based upon iterative transformations and candidate geometric shapes. In the preferred embodiment Hausdorff structures are used to realize &lgr;n-arbitrary different radiation patterns, including patterns optimized for multiple frequencies. The most preferred approach applies a sequence of different Hutchinson operators to different geometric subsets, thereby achieving patterns which are not only arbitrary in terms of wavelength/frequency, but also permit variable radiation patterns and variable polarization other desirable criteria. In addition to the use of variable scaling, geometric patterns, and the like, multiple structures may be placed within the same spatial footprint to permit reception over more bands.

Abstract: A cam follower having a clamp disposed on at least one end thereof. The follower includes two opposing sidewalls interconnected by a lower pallet. A roller is rotatably mounted to and disposed between the sidewalls via needled or journal bearings or other rotatable connection known in the art. A clamp is disposed about an end of the follower to induce compression force in the pallet and possibly act as the valve guide walls. The clamp increases the stiffness of the follower and induces compressive stress in the pallet area thereby increasing fatigue life. The clamp could also increase the length of the valve guide walls for better stability during engine assembly.

Abstract: A roller finger follower (RFF) wherein the shaft of the roller bearing is restrained in the follower finger by the overhead cam. Ends of the shaft are positioned in place in the follower finger by notches formed in the side walls of the follower finger. The notches restrain the shaft from axial movement. The cam in position over the RFF keeps the shaft nested in the notches. Further restraining means are disclosed to keep the shaft loosely nested in the notches in the follower finger before the cam is installed in position.

Abstract: A valve actuation assembly for an internal combustion engine is disclosed in which a rotatable rocker arm assembly is actuated by an engine driven camshaft to move a poppet valve reciprocably. The rocker arm assembly includes a hydraulic lash adjuster for disposition between the rocker arm and the valve stem. The lash adjuster includes an actuator at one end having an axially extending neck which terminates in an enlarged head. The enlarged head engages a foot assembly which includes a disk having a socket in which the head is positioned. A retainer ring is disposed in the socket and includes a wall portion which operates to establish an interference fit with the socket so as to fix the ring in the socket and a radially inwardly extending flange member which operates to define an opening through which the actuator neck extends but having a diameter less than that of the enlarged head portion of the actuator to thereby prevent removal of the head from the socket.

Abstract: A valve actuation assembly for an internal combustion engine is disclosed in which a rotatable rocker arm assembly is actuated by an engine driven camshaft to move a poppet valve reciprocably. The rocker arm assembly includes a hydraulic lash adjuster for disposition between the rocker arm and the valve stem. The lash adjuster includes an actuator at one end having an axially extending neck which terminates in an enlarged head. The enlarged head engages a foot assembly which includes a disk having a socket in which the head is positioned. Retention of the foot member to the enlarged head is through an interference between the perimeter of the enlarged head portion and the socket opening which is defined by a radially inwardly extending flange.