Abstract: Techniques are disclosed that can be used to increase the dynamic range of a microchannel plate (MCP) device, thereby eliminating the need for conventional techniques such as gating. In one example embodiment, an MCP device is provided that includes a plurality of channels, each channel for amplifying a photoelectron input to the channel and for producing an electron cloud at its output. The device further includes one or more charging switches associated with each channel for allowing charging current to flow so as to charge that channel in response to producing an electron cloud. In some such example cases, the plurality of channels and the one or more switches are implemented in silicon, and the one or more charging switches turn on only in the presence of the electron cloud produced at the corresponding channel output.

Abstract: Techniques are disclosed that can be used to interface a microchannel plate (MCP) with readout circuitry. The techniques can be employed, for instance, with MCP based devices used in a numerous sensing/detection applications, and are particularly suitable for applications where it is desirable to interface an MCP having a relatively large active area to a readout circuit having a relatively smaller active area. The interface effectively decouples anode geometry from ROIC geometry and may also be configured with flexible anode pad geometry, which allows for compensation of optical blur variations as well as a very high fill factor. The interface can be made using standard semiconductor materials and photolithography techniques, and can be configured with thermal expansion qualities that closely track or otherwise match that of the readout circuitry.

Abstract: The elements of a phased array antenna are driven by different frequencies, rather than the same frequency, to realize a scanning beam. The scan rate of the beam may be set arbitrarily high according to the frequencies used to drive the phased array, without expensive phase modulators. In particular, each successive element of the phased array antenna is driven with a frequency that is offset from the frequency used to drive the previous element in direct proportion to the spacing between antenna elements. Thus, for a straight line implementation of a phased array antenna with an antenna spacing offset of ?/2, the frequency offset between adjacent antenna elements is constant. For implementations of phased array antennas with another linear or a non-linear spatial relationship between antenna elements, the frequency offset between adjacent antenna elements is determined based on a linear or non-linear spatial relationship of the antenna.

Abstract: Techniques are disclosed that allow for resource allocation during situations requiring co-existence in cognitive radios. Even under situations of bandwidth scarcity, the techniques allow various users to be guaranteed quality of service (QoS) by proper distribution and allocation of resources. The techniques allow wireless communication systems to operate in a normal mode and a co-existence mode. In the co-existence mode of operation, sub-frame creation, sharing and zone formation schemes are implemented that enable the existing underlying frame structure to remain intact and inter-operable with the legacy systems and at the same time, provide a guaranteed QoS. The zones effectively create partitions in space, time and frequency, which result in interference avoidance and allow various users in neighboring cells to communicate on the same frequencies.

Abstract: Techniques for generating terahertz (THz) radiation are provided in which each nonlinear crystal in an array of such crystals is coupled to one or more corresponding waveguides such that any THz radiation generated in any single crystal is coupled into that crystal's THz waveguide structure. After the THz radiation is generated in the crystals and coupled into the waveguides, the individual THz signals may be coherently combined to form a single THz signal (non-coherent configurations are provided as well). Crystal-waveguide arrays embodying the techniques can be used to implement efficient, robust, and compact THz sources suitable for applications such as security screening, medical imaging, quality control and process monitoring in manufacturing operations, and package and container inspection.

Abstract: A nanostructure and method for assembly thereof are disclosed. An exemplary nanostructure includes a photocatalytic nanoparticle; a first tier of metal nanoparticles, each metal nanoparticle of the first tier being linked about the photocatalytic nanoparticle; and a second tier of metal nanoparticles, each metal nanoparticle of the second tier being linked to one of the metal nanoparticles of the first tier and located a distance from the photocatalytic nanoparticle greater than a distance between a metal nanoparticle of the first tier and the photocatalytic nanoparticle.

Abstract: A threat detection system and method protects an object of interest (such as, but not limited to, manned and unmanned aircrafts, vehicles, vessels, and buildings) from potential weapons (such as, but not limited to, a missile, an aircraft, a vehicle, a vessel, or the like). The threat detection system transmits a hi-powered, extremely short-pulsed non-directional laser signal. Because the pulse time of the laser signal is so short (a few tenths of a nanosecond), the laser signal is substantially only reflected off optics that are pointed or aimed at the object to be protected. The reflected laser signals are received by the threat detection system and are then compared with the transmitted laser signals to determined the direction, speed, distance and potentially identity of the potential weapon. Because the threat detection system is not based on movement alone, it is capable of detecting a potential weapon while in flight or prior to launch.

Abstract: One embodiment is a system for processing a complex ambiguity function (CAF) comprising creating a CAF surface from incoming data and a model vector, wherein the CAF surface has at least one feature, processing for a peak value, establishing a sub-window about the peak, wherein the peak is within the sub-window, and flattening the peak.

Abstract: Multiple RFID integrated circuit microradio chips are located at the feed point of an RFID tag antenna for greater reliability, elimination of testing and to take advantage of coherent microradio operation for increased gain and power, better signal-to-noise ratios, improved range and low bit error rates.

Abstract: An imaging catadioptric spectrometer using a Mangin type lens and pupil lens adjacent to a grating. Electromagnetic radiation received by aperture slits is directed to a reflective portion of a Mangin type lens and redirected to a pupil adjacent a diffraction grating. Diffracted light is transmitted through a refractive portion of the Mangin type lens and through a corrector lens to image the spectral components of electromagnetic radiation onto a detector. The detector may be an enhanced detector utilizing an array of smaller spaced detectors. By balancing the powers of the lens elements, a single optical material may be used. In one embodiment, multiple aperture slits are spaced apart and decentered with respect to the optical axis permitting collection of opposing diffraction orders on two detectors. A wide field of view having a low F number is obtained with an operating wavelength range in the infrared from approximately 7.5 to 13.5 microns.

Abstract: A convenient handheld locator is provided for locating an item in an urban environment in which the locator is programmed to search for and locate specific items, with the detected item being displayed on the locator as to its identity or name, also displaying where the item is relative to the locator, as to position and range.

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: An X-band, crossed dipole turnstile antenna configured to be omni-directional with horizontal polarization is disclosed. It comprises a set of two dipole antennas aligned at right angles to each other attached to a common 50 ohm coaxial feedpoint and fed 90 degrees out-of-phase. The antenna pattern is nearly omnidirectional in the horizontal plane. The antenna can be used generally in microwave communications including Digital Radio Frequency Tags (DRaFTs) communicating with airborne and satellite platforms.

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 method for generating electromagnetic waves in the ELF/ULF comprising the steps of using a ground-based Horizontal Electric Dipole (HED) antenna to send electromagnetic pulses upwardly in the E-region of the ionosphere to form an oscillatory or pulsed electric field; allowing said pulsed electric field to interact with magnetized plasma of the lower ionosphere to generate a pulsed horizontal and vertical current which have associated Horizontal and Vertical Electric Dipole moment; and allowing them to radiate.

Abstract: In a method and apparatus for controlling the deployment of a towline connecting a mooring craft to an ejected object comprising the steps of monitoring velocity to determine when a point for optimum braking has been achieved and then engaging a brake system to retard deployment of the towline, a DC motor augments and controls the brake system. The DC motor further controls the retrieval of the object. A cutter mechanism uses a first blade to grip the towing cable to maintain tension thereon as a second blade cuts the cable. A spring biased boom in combination with spring biased fins on the ejected object rapidly deploys the object from its storage housing. A locking mechanism secures the deployment mechanism in a stable locked position upon the object reaching its fully extended position.

Abstract: In an embodiment, a quantity smoother includes a first stage and a second stage. The first stage is operable to receive a sequence of raw samples of a quantity and to generate from the raw samples intermediate samples of the quantity, the intermediate samples having a reduced level of fluctuation relative to the sequence of raw samples. The second stage is coupled to the first stage and is operable to generate from the intermediate samples resulting samples of the quantity, the resulting samples having a reduced level of fluctuation relative to the sequence of intermediate samples. For example, such a quantity smoother may be part of a target-ranging system on board a fighter jet, and may smooth an error in an estimated target range so that the fighter pilot may more quickly and confidently determine in his head a range window within which the target lies.

Abstract: A system is provided for detecting the passage of vehicles and the classification thereof by weight using geophone outputs and a unique density measurement in which the number of peaks of the geophone signal above a predetermined threshold over a number of time frames indicates the presence of a vehicle, with the number of time frames in which the density exceeds the threshold indicating whether the vehicle is a heavy vehicle such as a tank, or a light vehicle such as a car, with the threshold eliminating both manmade and natural noise, as well as distinguishing seismic vibrations due to personnel and animals. In one embodiment, various thresholds are utilized to detect the onset of vehicle presence and the end of the event.

Abstract: Techniques are disclosed for optical switching and data control, without the interaction of electronic switching speeds. In one example embodiment, a common cavity optical latch is provided that that can hold an optical state for an extended period of time, and the operation of which is controlled optically. Optical phase control allows optical modal switching to be employed between two common optical cavities, using incident optical signals and the way in which the cavities manipulate the phase within them to lock in one or the other configuration, thereby forming an optical latch. The optical latch is implemented in an integrated fashion, such as in a CMOS environment.