Abstract: A fixed beam ramp electromagnetic band gap (EBG) antenna including a radiating element and an electromagnetic band gap (EBG) structure both disposed within a ramped cavity. The cavity is designed with the ramp leading to the EBG structure disposed about a base of the cavity. The radiating element can be disposed above the EBG structure and the EBG structure may have a plurality of unit cells. The EBG structure can be provided both, horizontally on the floor of the cavity and vertically along a back wall of the cavity. The use of both horizontal and vertical EBG structures combined with the ramped cavity increases the bandwidth and enhances the beam steering of the antenna system.

Abstract: A fixed beam ramp electromagnetic band gap (EBG) antenna including a radiating element and an electromagnetic band gap (EBG) structure both disposed within a ramped cavity. The cavity is designed with the ramp leading to the EBG structure disposed about a base of the cavity. The radiating element can be disposed above the EBG structure and the EBG structure may have a plurality of unit cells. The EBG structure can be provided both, horizontally on the floor of the cavity and vertically along a back wall of the cavity. The use of both horizontal and vertical EBG structures combined with the ramped cavity increases the bandwidth and enhances the beam steering of the antenna system.

Abstract: An external jet nozzle mixer includes identically formed lobes. The external mixer works with the internal mixer further to mix the engine internal bypass flow with the internal jet engine core flow to level the disparate flow velocities, to reduce the peak velocities from the jet engine core and increase the lower bypass velocities of the engine internal bypass flow, and thereby reduce noise. The internal lobe contours act as lifting flutes, causing mixing of the primary hot and cold flows to mix before exiting the nozzle. The external lobe contours act as venturi chutes, accelerating the cooler ambient secondary air flow. The lobes thus act collectively as an injector to force the cooler ambient secondary flow into the previously mixed primary flow as it exits the nozzle. Also obtained is an increased thrust efficiency and, consequently, decreased fuel consumption and engine emissions.

Abstract: A second stage external jet nozzle mixer (20) includes identically formed lobes which equal in number the lobes of the first stage internal mixer. The external mixer works with the internal mixer, and furthers the mixing of the jet engine internal bypass flow with the internal jet engine core flow. This mixing levels the disparate flow velocities attendant with the jet engine exhaust, reduces the peak velocities from the jet engine core and increases the lower bypass velocities of the jet engine internal bypass flow. The lobes include complex curvatures that greatly enhance mixing of the gases and ambient cooling air, and thereby reduce noise. At the lobe terminus, the lobe dimensional characteristics may be adjusted to thereby adjust the total terminus area to achieve a match to a jet engine to cause that jet engine to run at a determined RPM and noise level. Noise attenuation may also be adjusted by changing lobe dimensions.

Abstract: An external jet nozzle mixer includes identically formed lobes. The external mixer works with the internal mixer further to mix the engine internal bypass flow with the internal jet engine core flow to level the disparate flow velocities, to reduce the peak velocities from the jet engine core and increase the lower bypass velocities of the engine internal bypass flow, and thereby reduce noise. The internal lobe contours act as lifting flutes, causing mixing of the primary hot and cold flows to mix before exiting the nozzle. The external lobe contours act as venturi chutes, accelerating the cooler ambient secondary air flow. The lobes thus act collectively as an injector to force the cooler ambient secondary flow into the previously mixed primary flow as it exits the nozzle. Also obtained is an increased thrust efficiency and a consequently decreased fuel consumption and engine emissions.

Abstract: A second stage external jet nozzle mixer (20) includes identically formed lobes which equal in number the lobes of the first stage internal mixer. The external mixer works with the internal mixer, and furthers the mixing of the jet engine internal bypass flow with the internal jet engine core flow. This mixing levels the disparate flow velocities attendant with the jet engine exhaust, reduces the peak velocities from the jet engine core and increases the lower bypass velocities of the jet engine internal bypass flow. The lobes include complex curvatures that greatly enhance mixing of the gases and ambient cooling air, and thereby reduce noise. At the lobe terminus, the lobe dimensional characteristics may be adjusted to thereby adjust the total terminus area to achieve a match to a jet engine to cause that jet engine to run at a determined RPM and noise level. Noise attenuation may also be adjusted by changing lobe dimensions.

Abstract: An external jet nozzle mixer (20) includes identically formed lobes (48), equal in number those of the internal mixer (42). External mixer (20) works with internal mixer (42), further to mix the engine internal bypass flow with the internal jet engine core flow, to level the disparate exhaust flow velocities, to reduce the peak velocities from the jet engine core and increase the lower bypass velocities of the engine internal bypass flow, and thereby to reduce noise. The internal lobe contours act as lifting flutes, causing mixing of the primary hot and cold flows before exiting the nozzle. The external lobe contours act as venturi chutes, accelerating the cooler ambient air secondary flow. The lobes thus act collectively as an injector to force the cooler ambient secondary flow into the previously mixed primary flow as it exits the nozzle. Also obtained is an increased thrust efficiency and a consequently decreased fuel consumption and engine emissions.

Abstract: A second stage external jet nozzle mixer (20) includes identically formed lobes which equal in number the lobes of the first stage internal mixer. The external mixer works with the internal mixer, and furthers the mixing of the jet engine internal bypass flow with the internal jet engine core flow. This mixing levels the disparate flow velocities attendant with the jet engine exhaust, reduces the peak velocities from the jet engine core and increases the lower bypass velocities of the jet engine internal bypass flow. The lobes include complex curvatures that greatly enhance mixing of the gases and ambient cooling air, and thereby reduce noise. At the lobe terminus, the lobe dimensional characteristics may be adjusted to thereby adjust the total terminus area to achieve a match to a jet engine to cause that jet engine to run at a determined RPM and noise level. Noise attenuation may also be adjusted by changing lobe dimensions.

Abstract: A dual-polarization common aperture antenna having fully populated common aperture dual polarized arrays. The inventive antenna includes a first and second arrays of radiating slots disposed in a faceplate. The second array is generally orthogonal and therefor cross-polarized relative to the first array. The first array is waveguide fed and the second array is stripline fed. In the illustrative implementation, the first array and the second array share a common aperture. The common aperture is fully populated and each array uses the aperture in its entirety. The first and second arrays of slots are arranged for four-way symmetry. Each slot in the first array is a vertically oriented, iris-excited shunt slot fed by a rectangular waveguide and centered on a broad wall thereof. The second array is a standing wave array in which each slot is an air cavity backed slot fed by an inverted micro-stripline offset from a center thereof.

Abstract: A dual-polarization common aperture antenna having fully populated common aperture dual polarized arrays. The inventive antenna includes a first and second arrays of radiating slots disposed in a faceplate. The second array is generally orthogonal and therefor cross-polarized relative to the first array. The first array is waveguide fed and the second array is stripline fed. In the illustrative implementation, the first array and the second array share a common aperture. The common aperture is fully populated and each array uses the aperture in its entirety. The first and second arrays of slots are arranged for four-way symmetry. Each slot in the first array is a vertically oriented, iris-excited shunt slot fed by a rectangular waveguide and centered on a broad wall thereof. The second array is a standing wave array in which each slot is an air cavity backed slot fed by an inverted micro-stripline offset from a center thereof.

Abstract: A second stage external jet nozzle mixer (20) includes identically formed lobes (48), which equal in number the lobes of the first stage internal mixer (42). The external mixer works with the internal mixer, and furthers the mixing of the jet engine internal bypass flow with the internal jet engine core flow. This mixing levels the disparate flow velocities attendant with the jet engine exhaust, reduces the peak velocities from the jet engine core and increases the lower bypass velocities of the jet engine internal bypass flow. Because noise is a function of jet exhaust velocity to the 7th power, and because peak velocities from the core flow are reduced, the jet noise is thereby reduced. In addition, the lobes of the external jet nozzle mixer are designed to entrain external air into the jet engine internal flow. This additional entrainment of external air further reduces the overall jet velocity, and further decreases noise. Implementation is effected by external lobe design.

Abstract: A cascade thrust reverser for use with a mixer/ejector noise suppressor has a set of internal blocker doors controllably moveable between a stowed position, where engine exhaust passes through and out the tailpipe, and a deployed position, where engine exhaust is blocked and redirected out a pair of cascades or louvers. External cascade doors cover the cascades from the outside during flight, but are moved aft, exposing the cascades, when the blocker doors are deployed subsequent landing. In a preferred embodiment, the cascade doors and the blocker doors are interconnected through a pair of actuation mechanisms, whereby movement of the cascade doors is sequenced to the motion of the blocker doors. The blocker doors and the cascade doors are shaped to provide a clean aerodynamic profile when stowed, so that the noise suppressor functions optimally. The actuation mechanisms also preferably include lock mechanisms for only allowing the thrust reversers to be deployed just subsequent landing.