Abstract: A flat panel antenna used at a wall in a through-the-wall CW radar application is spaced from the wall by a half wavelength to eliminate the effects of energy reflected by the wall back to the antenna. In one embodiment, a ½-wavelength dielectric absorbing material insert is placed adjacent the flat panel antenna, which allows the flat panel antenna to be pressed against the wall for antenna stabilization, with the index of refraction of the material desirably being 3.

Abstract: An air-based vertical launch system is described by means of which ballistic missile defense can be achieved effectively from a large aircraft. A method for ensuring safe missile egress is proposed. A method for ensuring that the missile strikes the ballistic missile payload section is also proposed. Together, the air basing method employing vertical (or near-vertical) launch and semi-active laser guidance yield an affordable and operationally effective missile defense against both tactical and long-range ballistic missiles. The affordability of missile defense is enhanced by the ability of an aircraft equipped with a vertical launcher to simultaneously carry out several defensive and offensive missions and to provide other capabilities such as satellite launch at other times.

Abstract: A broadband transmission line impedance transformer performs impedance transformation with improved frequency response and efficiency across a wide operational bandwidth. In particular, the bandwidth of a transmission line 2:1 impedance transformer may be significantly increased by adding an additional compensating capacitor as an internal component between interconnected transmission lines. This capacitor effectively improves low frequency response for a given length of transmission lines and decreases mismatch in an entire frequency range. The overall bandwidth ratio increases at least twice and mismatch decreases.

Abstract: A monolithically integrated light-activated thyristor in an n-p-n-p-n-p sequence consists of a four-layered thyristor structure and an embedded back-biased PN junction structure as a turn-off switching diode. The turn-off switching diode is formed through structured doping processes and/or depositions on a single semiconductor wafer so that it is integrated monolithically without any external device or semiconductor materials. The thyristor can be switching on and off optically by two discrete light beams illuminated on separated openings of electrodes on the top surface of a semiconductor body. The carrier injection of the turning on process is achieved by illuminating the bulk of the thyristor with a high level light through the first aperture over the cathode to create high density charge carriers serving as the gate current injection and to electrically short the emitter and drift layer.

Abstract: Member nodes of a wireless point-to-multipoint (PMP) network may participate in mobile ad hoc (MANET) or mesh communications with other nodes on the same channels used by the network for PMP communications. A PMP network base station node transmits a downlink signal defining a downlink map for scheduling first time periods for transmitting messages to subscriber station nodes, and an uplink map for scheduling second time periods allowing a subscriber station node to transmit messages to the base station node in a scheduled second time period. A MANET/mesh zone is allocated in either or both the downlink and the uplink maps, each zone operating to reserve one or more time slots and channels in which the base station and other nodes may communicate using a MANET/mesh protocol, thus avoiding interference with communications that are being conducted between the base and the subscriber station nodes under the PMP protocol.

Abstract: A process for preparing trinitrotoluene (TNT) in which toluene is treated with nitric acid having a concentration of about 90% to about 99%, and preferably about 98% to about 99%, by weight at a temperature of less than about 60° C., and preferably less than 30° C., to produce high purity dinitrotoluene. The resulting dinitrotoluene is then treated with nitric acid having a concentration of about 98% to about 99% by weight and trifluoromethane sulfuric acid to produce high purity TNT.

Abstract: What is provided is the use of an array of E-field sensors to detect the closest approach of incoming projectiles and to determine through time difference of arrival the bearing of the incoming projectile, thus to identify the bearing of the source of the projectile. dE/dT processing of the individual outputs of the E-field sensors indicates by the zero crossing the peak of the E-field disturbance and thus the instance of time of the closest approach of the projectiles to a sensor.

Abstract: Kalman gain is used to calculate range accuracy for a passive angle-of-arrival determining systems, most notably for short-baseline interferometry, in which Kalman gain after arriving at a minimum proceeds to within a predetermined fraction or percent of zero gain, at which time the range estimate accuracy is known.

Abstract: Systems including both distributed and centralized architectures for providing multiple levels of security using “virtual” switches. Ports and channels are assigned the same time slots on a TDMA bus only when they have matching security levels.

Abstract: A Thulium laser (15) is used to directly drive a ZnGeP2 optical parametric oscillator (30) with a nominal 2 ?m output to generate the 3-5 micron wavelengths. In one embodiment, the ZGP OPO is configured as a linear resonator and in another embodiment the ZGP OPO is configured as a ring resonator. The ring resonator prevents optical feedback to the Thulium laser (15) and eliminates the need for an optical isolator (24). Moreover, the Thulium laser pump (15) is implemented as a Tm:YAlO3 laser in which YAlO is the host for the Thulium YAlO is particularly beneficial as it is a mechanically hard optical material allowing high thermal loading without fracture as well as natural birefringence that can minimize thermal birefringence losses. A longer wavelength transition at 1.99 microns is selected to minimize nonlinear crystal loss. More particularly, a high power, high efficiency Tm:YAlO3 laser repetitively Q-switched at 10 kHz is used to drive a ZnGeP2 OPO.

Abstract: A compact polarization agile antenna includes a dual-orthogonal loop structure which is excited by a single RF feed (21). The loop structure includes a pair of loops (8, 10), each loop is connected to ground (45) through a complex impedance via a solid state switch (41, 43). Current flows in the loop when the switch (41, 43) is closed. The switches (41, 43) and impedances (47, 49) in each leg are independently controlled. Additionally, the relative phase of the current in each leg can be controlled over a narrow bandwidth via a complex impedance for narrowband circular polarized applications. Using this approach, orthogonal linear, slant, or left-hand and right-hand circular polarizations can be generated.

Abstract: A method of two-source passive ranging comprising the steps of determining the coordinates of a first position and a second position wherein a first soldier or ground vehicle is located at the first position and a second soldier or ground vehicle is located at the second position; determining individual angles between said first and second positions and a radio frequency source; and using individual single-angle accuracy values to estimate the range from the first and second positions to the radio frequency source.

Abstract: In a CW radar system for detecting motion behind a wall (12) involving modulation of the radar transmission, means (34) are provided to interrupt the CW wave when motion is detected and to use the same radar transmitter (30) to transmit a serial digital message to a remote monitoring receiver (34). The encoding can include a receiver wakeup message to turn on the receive only when motion has been detected. In one embodiment, a microprocessor (28) is used to detect when motion exists behind a wall and to provide a tailorable message to modulate the radar's transmitter in the period when the CW signal from the radar is turned off after the motion detector.

Abstract: A high intensity, low frequency underwater transducer for non-lethal deterrence of terrorist swimmers or divers in a body of water. The invention consists of a motor driven flextensional underwater transducer. In one embodiment, the phase of a transducer is sensed, enabling multiple projectors to achieve high acoustic sound pressure levels by beamforming and/or modal constructive interference (e.g. taking advantage of harbor bottom topography and boundaries.).

Abstract: A room temperature operation polycrystalline infrared responsive photodetector, manufactured by a process, comprising the steps of patterning vacuum-deposited material and dry-etching a photonic crystal structure with resonant coupling tuned to long wavelengths.

Abstract: A lightweight broadband blade antenna assembly is incorporated into the surface of an airfoil, such as a structure component of an aircraft, or a separate airfoil (blade antenna) attached thereto. A first metallized area is formed on the airfoil adjacent a leading edge of the airfoil. A second metallized area is formed on trailing edge of the airfoil and is spaced from the first metallized area by a first gap which is configured to provide a capacitive coupling between the first and second metallized areas. A third metallized area is formed on the cap portion of the airfoil and is spaced from the first metallized area by a second gap and is electrically connected in series with the first and second metallized areas. RLC circuits are electrically connected across tuning gaps formed in the third metallized area to provide a broadband response.

Abstract: A method for early detection of faulty antenna arrays comprising the step of treating said detection as a special case of target recognition; wherein targets of interest are all previous examples of defective antenna arrays.

Abstract: A reconfigurable compute engine interconnect fabric includes a reconfigurable interconnect layer (24, FIG. 2) between an application layer (22) and a physical layer (26) which identifies the input and output pins for the engine and their functions.

Abstract: An air-based vertical launch system is described by means of which ballistic missile defense can be achieved effectively from a large aircraft. A method for ensuring safe missile egress is proposed. A method for ensuring that the missile strikes the ballistic missile payload section is also proposed. Together, the air basing method employing vertical (or near-vertical) launch and semi-active laser guidance yield an affordable and operationally effective missile defense against both tactical and long-range ballistic missiles. The affordability of missile defense is enhanced by the ability of an aircraft equipped with a vertical launcher to simultaneously carry out several defensive and offensive missions and to provide other capabilities such as satellite launch at other times.

Abstract: What is provided is a receiver-on-a-chip comprising a monolithic integrated circuit that reduces the receiver to a cigarette-pack-sized assembly mountable directly at an antenna element, with a much-increased operational bandwidth and instantaneous bandwidth, increased dynamic range and with a two-order-of-magnitude decrease in size and weight. Moreover, because of the elimination of all of the I/O drivers and attendant circuitry, power consumption is reduced by two-thirds, whereas the mean time before failure is increased to 10,000 hours due to the robustness of the monolithic integrated circuit and use of fiber optics.