Abstract: An electrical amplifier unit which removably attaches to a gas mask and includes a microphone for detecting voice sounds emitted by the wearer of the gas mask, circuitry for amplifying the detecting sound, and a loudspeaker for emitting the amplified sounds externally of the mask. The associated components are contained within a housing that attaches sealably to the outlet port of a gas mask. The amplifier unit is quickly and easily attachable to commercially available gas masks without additional hardware and does not affect the structural and functional integrity of the host mask.

Abstract: A high-gain digitally tuned antenna system comprises a modified swept-back fractal (MSBF) radiator element, with the fractal preferably being a Sierpinski carpet fractal based on a parallelogram. A digital tuning circuit coupled to the radiator comprises an array of inductors which can be selectively connected to form a network which tunes the antenna system to a selected tuning frequency. The system is preferably arranged to selectively connect the inductors in series such that the combined inductances substantially cancel the capacitance of the radiator at a selected tuning frequency. The antenna system is preferably arranged to operate over the 30-88 MHz, 108-174 MHz, and 225-600 MHz bands, with a radiator height of 15? or less.

Abstract: An electrical amplifier unit which removably attaches to a gas mask and includes a microphone for detecting voice sounds emitted by the wearer of the gas mask, circuitry for amplifying the detecting sound, and a loudspeaker for emitting the amplified sounds externally of the mask. The associated components are contained within a housing that attaches sealably to the outlet port of a gas mask. The amplifier unit is quickly and easily attachable to commercially available gas masks without additional hardware and does not affect the structural and functional integrity of the host mask.

Abstract: Antenna system embodiments are illustrated that include a planar, top-loaded dipole antenna and a planar elliptical dipole antenna arranged substantially coplanar and within the top-loaded dipole antenna. These antenna structures facilitate their combination with tuning coil chains, baluns and impedance matching circuits to operate over multiple frequency bands. System embodiments exhibit high gain and selectivity and may be digitally tuned over wide frequency bands (e.g., 30-600 MHz). The embodiments may be digitally tuned to support operational modes such as frequency hopping to thereby realize a secure communication system. Because these embodiments are configured to operate in the absence of a ground plane, they are especially suited for mounting on various portions of an aircraft's structure. For example, they may be configured as winglets and situated far out on wingtips to thus free the remainder of an aircraft's structure for other operational systems.

Abstract: An acoustic transducer array element includes a plurality of individual or transducer assemblies or “drivers” which are combined in a closely spaced geometry to form the array element. The respective transducer assemblies within each array element are acoustically coupled with each other. The invention utilizes such mutual coupling between the closely spaced transducers assemblies to provide improved acoustic performance.

Abstract: Antenna embodiments are illustrated that are particularly suited for use in aircraft navigation, identification and collision avoidance systems. An exemplary antenna embodiment operates about a center wavelength and in association with a ground plane and comprises first and second grounded, shortened, and top loaded monopoles. These monopoles are spaced apart above a ground plane and each of them includes a feed post, a shorted post, and a top load wherein the shorted post is spaced from the feed post, is coupled to the ground plane, and has a length less than one fourth of the center wavelength. In addition, the top load is coupled to the feed post and the shorted post and is configured along orthogonal minor and major axes of the top load to have a width along the minor axis and a length along the major axis that exceeds the width.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; and at least one amplifier associated with each optical receiver. The interrogator also includes, alternatively, a driver/modulator for the optical source providing on/off pulses; an analog integrator following the at least one amplifier; or a mechanism compensating for masking of one sensor fiber optic grating by another.

Abstract: A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.

Abstract: A sensor apparatus combines an optical sensor in which acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output, coupled to a high speed interferometric interrogator, through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator.

Abstract: An interrogator for a plurality of sensor fiber optic gratings. The interrogator includes a broadband optical source; at least one beam splitter directing output of the optical source to the sensor fiber optic gratings; at least one linear filter for converting changes in peak reflection wavelength to changes in intensity; at least one optical receiver; at least one amplifier associated with each optical receiver; and an active closed-loop circuit following the at least one amplifier to provide bias voltage stabilization.

Abstract: Compact top-loaded, fractal monopole antenna system embodiments are provided for multi-band airborne operation over ultrabroadband ranges (e.g., 30 to 2000 MHz). These multi-band embodiments are self-contained, aerodynamic and compact (e.g., blade height less than 9.5 inches) and are power efficient with a low return loss (e.g., less than ?7 dB). System embodiments include a set of impedance-matching circuits configured to substantially match an antenna impedance to a predetermined system impedance over a set of predetermined frequency bands. In an embodiment, at least one impedance-matching circuit includes a chain of selectable air-core inductors which are novelly arranged to improve radiation efficiency and prevent damage to support substrates. In an embodiment, a lowest-frequency one of the impedance-matching circuits is configured to process signals having a maximum wavelength ?max wherein a fractal member is configured with a length that does not exceed ?max/40.

Abstract: A fiber optic interrogator includes a broadband optical source, at least one beam splitter directing output of the optical source to an array of fiber optic gratings, at least one linear transmission or reflection filter, at least one optical receiver and at least one amplifier associated with each receiver. In one aspect of the invention, a linear transmission filter is used to convert the change in center wavelength of a grating reflectivity spectrum to a change in intensity, which is proportional to the change in the grating central wavelength. In another aspect of the invention, a pair of opposite-sloped linear transmission filters are utilized to normalize the received and filtered reflections with respect to total optical power. In another aspect of the invention, the optical source is pulsed, and return pulses from each fiber optic grating to be measured are sampled by the interrogator at different times.

Abstract: A fiber optic interrogator includes a broadband optical source, at least one beam splitter directing output of the optical source to an array of fiber optic gratings, at least one linear transmission or reflection filter, at least one optical receiver and at least one amplifier associated with each receiver. In one aspect of the invention, a pair of opposite-sloped linear transmission filters are utilized to normalize the received and filtered reflections with respect to total optical power.

Abstract: A billing system for determining package transportation charges. The billing system includes a reader to read a package identifier associated with said package and the reader generates a package identifier signal and transmits the same to a microprocessor. The billing system also includes a package sizer having a plurality of non-contact optical sensors located along each of an x, y and z axis, where each optical sensor is in a known position. The sensors are oriented relative to the conveyor so that packages passing over the sensors are detected by the sensors and produce a signal correlated to said package size. Also provided is a microprocessor to receive and correlate said package size and identifier signals, and to determine an appropriate shipping charge based upon the same. A weigh scale may also be incorporated into the system. A method of determining a transportation charge is also comprehended, which includes a self-diagnostic initialization procedure.

Abstract: Antenna system embodiments are shown which are especially suited for mounting on aircraft and for operation across widely-spaced frequency bands. Embodiments include blade members positioned in a ring arrangement and tuning circuits that are each coupled between a respective pair of the blade members and configured to successively remove blade members from operation as the operational frequency increases.

Abstract: A billing system for determining package transportation charges. The billing system includes a reader to read a package identifier associated with said package and the reader generates a package identifier signal and transmits the same to a microprocessor. The billing system also includes a package sizer having a plurality of non-contact optical sensors located along each of an x, y and z axis, where each optical sensor is in a known position. The sensors are oriented relative to the conveyor so that packages passing over the sensors are detected by the sensors and produce a signal correlated to said package size. Also provided is a microprocessor to receive and correlate said package size and identifier signals, and to determine an appropriate shipping charge based upon the same. A weigh scale may also be incorporated into the system. A method of determining a transportation charge is also comprehended, which includes a selfdiagnostic initialization procedure.

Abstract: A billing system for determining package transportation charges. The billing system includes a reader to read a package identifier associated with said package and the reader generates a package identifier signal and transmits the same to a microprocessor. The billing system also includes a package sizer having a plurality of non-contact optical sensors located along each of an x, y and z axis, where each optical sensor is in a known position. The sensors are oriented relative to the conveyor so that packages passing over the sensors are detected by the sensors and produce a signal correlated to said package size. Also provided is a microprocessor to receive and correlate said package size and identifier signals, and to determine an appropriate shipping charge based upon the same. A weigh scale may also be incorporated into the system. A method of determining a transportation charge is also comprehended, which includes a self-diagnostic initialization procedure.

Abstract: A package measurement apparatus comprising three measurement devices, one for each dimension. Each measurement device comprises a plurality of signal receptor modules. Each module comprises a row of signal receptor, and a signal energy source. In a first calibration step, the outputs of each receptor are standardized to reference maximums and minimums. In a second calibration step, calibration sets of receptor outputs are created and recorded. During measurement, a measurement set of receptor outputs is obtained and matched with a calibration set of receptor outputs to determine the dimension of an object.

Abstract: An acoustic transducer array element includes a plurality of individual or transducer assemblies or “drivers” which are combined in a closely spaced geometry to form the array element. The respective transducer assemblies within each array element are acoustically coupled with each other. The invention utilizes such mutual coupling between the closely spaced transducers assemblies to provide improved acoustic performance.

Abstract: A package measurement apparatus comprising three measurement devices, one for each dimension. Each measurement device comprises a plurality of signal receptor modules. Each module comprises a row of signal receptor, and a signal energy source. In a first calibration step, the outputs of each receptor are standardized to reference maximums and minimums. In a second calibration step, calibration sets of receptor outputs are created and recorded. During measurement, a measurement set of receptor outputs is obtained and matched with a calibration set of receptor outputs to determine the dimension of an object.