Award Data

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THE PROPOSED PROGRAM IS A FEASIBILITY STUDY AND SYSTEM DESIGN FOR AN INNOVATIVE POWER-AMPLIFIER SYSTEM FOR THE ADAPTIVE-JAMMER APPLICATION. THIS SYSTEM OPERATES OVER THE ENTIRE HF AND VHF RANGE (3 - 300 MHZ), PRODUCES SIGNALS WITH VARIOUS TYPES OF MODULATION, AND CAN CONCENTRATE ALL OF ITS POWER ON A SINGLE TARGET OR DIVIDE ITS POWER AMONG SEVERAL TARGETS. ITS POWER AMPLIFIERS CAN BE OPERATED IN C ...

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OPERATION OF A JAMMER TRANSMITTER FROM A SMALL PLATFORM (RPV OR JEEP) NECESSITATES THE USE OF ELECTRICALLY SHORT ANTENNAS SUCH AS SHORT WHIPS AND SMALL LOOPS. THE CONVENTIONAL APPROACH USES A POWER AMPLIFIER DESIGNED FOR A 50-OHM LOAD AND AN ANTENNA TUNER THAT MATCHES THE ANTENNA-INPUT IMPEDANCE TO OHMS. HOWEVER, THE RAPID FREQUENCY CHANGES REQUIRED BY JAMMERS PRECLUDE THE USE OF ANTENNA TUNING. T ...

MODERN HF/VHF JAMMERS EMPLOY POWER COMBINERS AND MULTIPLE POWER-AMPLIFIER (PA) MODULES TO ACHIEVE A HIGH POWER OUTPUT, CANCELLATION OF HARMONICS, AND GRADUAL DEGRADATION OF PERFORMANCE DUE TO MODULE FAILURE. POWER COMBINERS CAN BE A SIGNIFICANT SOURCE OF POWER LOSS BECAUSE OF RESISTIVE LOSSES, MISMATCH (AMPLITUDE/ PHASE) OF PA OUTPUTS, AND PA INEFFICIENCY DUE TO NONNOMINAL LOAD. CURRENTAND VOLTAGE ...

The RF transmitter/locator (TL) concept presented in this proposal enables the location and recovery of a canister such as a nose cone, artillery shell, buoy, or instrument package. The system operates over a distance of 5 mi on the surface and several hundred feet through soil, sand, or fresh water. The RF TL is battery-powered, small in size, highly shock resistant, and it consumes a minimum amo ...

Inside Out vs Outside In! It seems reasonable to hypothesize that the pilot of an air vehicle will feel more in harmony with the actions of his vehicle when he is at the relative "origin" of the coordinate frame of reference of that vehicle ... and will respond more quickly and with greater accuracy, precision, and efficiency. Experience teaches that this occurs for a piot when utilizing an "insid ...

The cost and limited lifespan of strain gages for stress and vibration surveys has driven researchers to find alternate means of investigating airfoil stress and vibration. Systems based on optical sensors have been reported in the literature since the mid 1960's. These systems have been limited to test cell use and relatively complex, thus preventing their widespread application. One recently d ...

Turboshaft engines are subject to various transient modes, necessitating a compressor with very high surge margin. Therefore, many devices were proposed in the past, and some of them including a recent one with a vaneless cavity by Allied Signal Engines, demonstrated impressive surge margin enhancement. However, there ahs been no detailed investigations on understanding the flow mechanism leading ...

Low cost compact diffusers are needed for small gas turbine compressor stages to economically minimize centrifugal compressor overall diameter yet permit high efficiency and wide operating range. The proposer has performed over 130 different detailed tests (on more than 40 different stage configurations) with various conventional and novel diffusers (vaneless, low solidity airfoil, channel, tande ...