Abstract: The fast switching multifunction antenna of the present invention is a variable length antenna that may be switched to provide the equivalent function of a broadband antenna. The variable length antenna quasi-continuously transmits or receives signals at a plurality of frequencies by changing the effective length of the antenna using a variety of switching mechanisms. The present invention may comprise a plurality of antenna segments, a plurality of selectively actuable switches for interconnecting the antenna segments, and a switching mechanism operably coupled to the plurality of selectively actuable switches for switching them at a switching rate that is greater than twice the highest frequency to be transmitted or received. The switching rate will be fast enough to allow the antenna to sample the highest frequency and all of the required lower frequencies within the desired frequency range without the loss of information at any frequency.

Abstract: A method for making transmission measurements in a dual-chambered anechoic chamber used in conjunction with spatial averaging. At selected transmitter antenna positions, measurement are taken at different frequencies. For each transmitter position, a measurement is made with the test device positioned between the apertures, and another without the test device. When all desired measurements have been made, the measurement data are spatially averaged; i.e., the measurements are scaled, summed, and averaged, providing more accurate transmission measurements.

Abstract: An electrically adjustable spectrometer uses collimated, P-polarized light made incident on a surface of an optically transparent liquid crystal input material. The material transmits the light to a boundary surface between the input material and an output optically transparent material. The input material is preferably highly dispersive, making Snell component values at the boundary surface markedly different for different wavelengths. The output material is preferably of low dispersion and high birefringence. Only one wavelength at the boundary surface has a Snell component value tangent to its corresponding index surface in the output section. Within this section, the ray vector for this wavelength is parallel to the boundary surface. Because optical energy propagates in the ray vector direction, only the narrow range of wavelengths having ray vectors substantially parallel to the boundary surface reach an output of the device.

Abstract: A nondestructive acoustic emission testing system using electromagnetic excitation, comprises: a) an electromagnetic wave generator for generating electromagnetic waves that stimulate a test sample to generate acoustic energy; b) an acoustic energy sensor for detecting the acoustic energy and generating a first output signal that represents the acoustic energy; and c) a data processor for comparing the output signal with a reference and for generating a second output signal that represents a characteristic of the test sample.

Abstract: An ultra-broadband antenna incorporated into an electrically nonconductive garment, with radiation absorber material to mitigate radiation hazard. The antenna includes first and second RF elements attached to the garment so that a gap exists between them, where the RF elements each form a band when the garment is worn by a wearer. RF and ground feeds are electrically connected to the first and second RF elements, respectively. A shorting strap electrically connected between the first and second RF elements on the anterior side of the garment generally opposite the feeds helps match the antenna impedance to an external signal source. Radiation absorber material disposed over the gap between the first and second RF elements and in a pocket in the region of the RF feed limits the wearer's exposure to electromagnetic field to acceptable levels.

Abstract: A dual-chambered anechoic chamber used in conjunction with spatial averaging for making transmission measurements of electromagnetic devices. The anechoic chamber includes a first tapered chamber with a first aperture, a second tapered chamber with a second aperture opposed to the first aperture, an alignment apparatus for aligning the two chambers and, if necessary, for positioning a test device between the apertures, and a positioning mechanism for mounting and determining the position of a transmitter antenna. A receiver antenna in the second chamber receives test signals transmitted from the transmitter antenna. At selected transmitter antenna positions, measurements are taken at different frequencies. For each transmitter position, a measurement is made with the test device positioned between the apertures, and another without the test device. When all desired measurements have been made, the measurement data are spatially averaged; i.e.

Abstract: An integrated optical waveguide sensor system includes: an optical waveguide having a monolithic and roughened metallic layer on which a self-assembled monolayer is formed; an optical energy source for generating an optical excitation signal; and a spectrometer for detecting spectra of optical energy emitted from the optical waveguide. The waveguide facilitates multiple SERS responses resulting from interactions between the optical excitation signal and an analyte of interest that may be present on the surface of the self-assembled monolayer. Thus, the sensor system provides a sensor for detecting organic contaminants with a sensitivity of ppm and even ppb in some cases.

Abstract: An accelerometer is based upon the monolithic integration of a Fabry-Perot interferometer and a p+n silicon photosensor. Transmission of light through a Fabry-Perot interferometer cavity is exponentially sensitive to small displacements in a movable mirror due to an applied accelerating force. The photosensor converts this displacement into an electrical signal as well as provides for additional amplification. Because the interferometer and photosensor are monolithically integrated on a silicon substrate, the combination is compact and has minimal parasitic elements, thereby reducing the accelerometer's noise level and increasing its signal-to-noise ratio (SNR).

Abstract: A method of predicting impending coastal seismic activity by using ocean-based acoustic sensors. Acoustic sensors are used to sense and record low frequency acoustic events, including primary and tertiary waves. Characteristics that may be sensed and recorded include frequency, amplitude, and duration of the acoustic events. More specifically, the occurrence of T-waves over a selected time period are sensed and recorded. A decrease in the rate of the occurrence of T-waves during a portion of the selected time period is an indication of impending seismic activity.

Abstract: A method for fabricating complementary vertical bipolar junction transistors of silicon-on-sapphire in fewer steps than required for true complimentary vertical bipolar junction transistors is disclosed. Initially a thin layer of silicon is grown on a sapphire substrate. The silicon is improved using double solid phase epitaxy. The silicon is then patterned and implanted with P+-type and N+-type dopants. Subsequently a micrometer scale N-type layer is grown that acts as the intrinsic base for both an PNP transistor and as the collector for an NPN transistor. The extrinsic base for the NPN is then formed and the emitter, collector and ohmic contact regions are next selectively masked and implanted. Conductive metal is then formed between protecting oxide to complete the complementary vertical bipolar junction transistors.

Abstract: An optical modulating device capable of use as a light valve, display, or optical filter, which uses variation in incident angle to exploit color-selective absorption at a metal-dielectric interface by surface plasmons. The device includes a dielectric layer, at least one metallic layer through which electromagnetic radiation may be transmitted or reflected, and incident and exit layers which are both optically transmissive. A beam steering mechanism controls the incident angle of the electromagnetic radiation. In one embodiment, an external beam steering mechanism is used to set the incident light angle onto the filter. In another embodiment, the filter is formed as an integral part of, for example, a cantilever. The incident light angle is then controlled by the angle of the filter cantilever.

Abstract: A camera controller incorporates a microcontroller for carrying out all controller functions. The microcontroller is operably coupled to a reprogrammable memory in which operating commands for the specific camera being used are stored. Thus the microcontroller can be configured to work with a great number of different cameras and command sets, based upon the specific camera being used. A memory that can be used for this purpose is an electrically erasable read only memory that, by using a programmable logic array and random access memory, can be reprogrammed in-place. The microcontroller is operably connected to a camera's “on/off”, zoom and focus functions so that these may be controlled via the controller. Also controlled by the invention is the automatic iris feature of a digital camera.

Abstract: The invention is designed to employ one or a multitude of sensors designed to allow operational monitoring of any of a variety of electromagnetic radiating tubes. Monitoring is conducted to detect a degradation in performance which can be used as a factor in deciding whether tube replacement is justified. Contrary to some past approaches that focused on averaged tube outputs, the invention is designed to examine individual tube pulses.

Abstract: An all solid-state light valve and tunable filter that uses color-selective absorption at a metal-dielectric interface by surface plasmons. The solid-state surface plasmon light valve and tunable filter comprises a substrate, a bottom electrode, a solid-state electro-optic material, and a top electrode through which electromagnetic radiation may pass through and whose optical properties may be modified by suitable modulation of an electrical bias, i.e., an applied voltage between the top and bottom electrodes. The bottom electrode must be specifically fabricated using a refractory metal to allow the formation of the solid-state electro-optic material.

Abstract: An ultra-broadband antenna is incorporated into an electrically nonconductive garment. The antenna includes first and second RF elements attached to the garment so that a gap exists between them, where the RF elements each form a band when the garment is worn by a wearer. RF and ground feeds are electrically connected to the first and second RF elements, respectively. A shorting strap electrically connected between the first and second RF elements on the anterior side of the garment generally opposite the feeds helps match the antenna impedance to an external signal source. A gap between the RF elements provides a voltage difference between the RF elements when the antenna is energized. Electrically conductive straps are electrically connected between the anterior and dorsal regions of the first RF element that extend over the shoulder region of the garment.

Abstract: A system for alternately directing optical energy through multiple optical modulation channels includes an optical switch having first and second optical output ports for alternately directing an optical signal at full input power out of first and second optical output ports; a first optical modulation channel for modulating the output signal received from the first optical output port; and a second optical modulation channel for modulating the output signal received from the second output port. The optical switch includes a Pockels cell and a birefringent mirror. The Pockels cell transforms a first polarization state of the optical signal into a second polarization state in response to receiving an input signal. The birefringent mirror allows the optical signal to propagate along a first axis when the optical signal has a first polarization state, and directs the optical signal along a second axis when the optical signal has a second polarization state.

Abstract: A microelectromechanical gas concentrator is fabricated for extracting a gaseous component from a gas mixture. The gas concentrator consists of an adsorbent member that alternatively moves between two regions on a single substrate. When the adsorbent member is in the first region, it is allowed to adsorb the gaseous component. When the adsorbent member moves to the second region, it is exposed to radiant energy, causing it to desorb the gaseous component. As the adsorbent member moves alternatively between regions, the gaseous component is adsorbed by the adsorbent member in the first region and desorbed in the second region, resulting in a pumping action that concentrates the gaseous component from one region to the other.

Abstract: An integrated circuit multiplexer comprises a waveguide having an interior cavity, first RF input port, and a first and second output ports; a dielectric structure positioned in the cavity; an RF input feed attached to the dielectric structure that extends through the RF input port; a first RF output feed attached to the dielectric structure that extends through the first RF output port; a second RF output feed attached to the dielectric structure that extends through the second RF output port; a first resonator pair mounted to the dielectric structure between the RF input feed and the first RF output feed, and electrically connected to the waveguide; and a second resonator pair mounted to the dielectric structure between the RF input feed and the second RF output feed, and electrically connected to the waveguide so that the first and second resonator pairs are generally coplanar.

Abstract: A three dimensional display provides a true 3-D display of an image defined by luminous voxels within a virtually transparent volume. The voxels may be generated by illuminating a virtually transparent fluorescent gas or dye with beams of excitation energy that cause the gas or dye to emit light at voxels where the energy beams intersect. The voxels may be refreshed in a manner to create either fixed or animated images.

Abstract: A sonar system that includes a new comb-like waveform constructed by modulating the tines of a comb spectrum according to a set of Hermite functions defining a Hermite Function Space (HFS), and a processing method that reduces the sidelobes of the ambiguity function associated with the normally-processed HFS comb waveform. Noise-limited performance remains high, because the waveform is designed to be power-efficient; range ambiguity is superior to the highly-rated sinusoidal frequency-modulation (SFM) waveform; and reverberation-limited performance is equal to or better than that offered by any other waveform designed for this purpose. The full Doppler sensitivity normally associated with pulsed CW can be realized by the application to HFS signals of the constrained, regularized deconvolution method of this invention.