Abstract: A multi-probe anechoic chamber (MPAC) for beam performance testing of a phased array system, including an active electronically steered array (AESA) system. The MPAC may comprise: an AESA antenna having a plurality of subarrays capable of emitting RF energy; an anechoic chamber having a wall, comprising a plurality of horn antennas for receiving the RF energy; a switch electrically coupled to the horn antennas for selectively coupling of the horn antennas to one or more output channels; various instruments electrically coupled to the output channels for measuring the RF energy; and a processor electrically coupled to the switch and the instruments for controlling the selective coupling of the switch, such that the processor and instruments cooperatively monitor and measure various beam parameters associated with the RF energy.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system. The use of digital local oscillators enable a compact, low power, monolithic architecture.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: A light guide illumination system, which is used in transmitting illumination from a central source to a variety of remote locations, comprises an illumination source, a configuration of transfer lenses disposed around the illumination source, which are each adapted to focus emitted light from the illumination source in a generally outward direction from the illumination source, a plurality of condenser lenses, and at least one light guide. Each of the plurality of transfer lenses are adapted to focus light into a corresponding condenser lens, and the at least one light guide is adapted to receive light from the condenser lenses. The combination of the several elements of the inventive system results in a very efficient transfer of the energy of the light source to the fibers.

Abstract: A light guide illumination system having a metal-halide double-ended illumination source is disclosed. The light guide illumination system includes at least one light guide and two curved reflectors disposed in proximity to the double-ended illumination source. The two curved reflectors are adapted to reflect the emitted light from the double-ended illumination source into the light guide. The light guide illumination system further includes at least one multi-sectored lens adapted to receive light from the light guide, and at least one output light guide. The multi-sectored lens is adapted to receive the reflected light from the light guide and to focus the light into the output light guide.

Abstract: The inventive system, which is used in transmitting illumination from a central source to a variety of remote locations, efficiently couples the light originating from a lamp, or similar source, into a multiplicity of flexible macroscopic fibers. The combination of the several elements of the inventive system results in a very efficient transfer of the energy of the light source to the fibers. Light from the lamp is fed to a ring-shaped configuration of ports, with each port having one or more flexible macroscopic fibers connected thereto.

Abstract: The inventive system, which is used in transmitting illumination from a central source to a variety of remote locations, efficiently couples the light originating from a lamp, or similar source, into a multiplicity of flexible macroscopic fibers. The combination of the several elements of the inventive system results in a very efficient transfer of the energy of the light source to the fibers. Light from the lamp is fed to a spherical configuration of ports, with each port having one or more flexible macroscopic fibers connected thereto.

Abstract: The inventive system, which is used in transmitting illumination from a central source to a variety of remote locations, efficiently couples the light originating from a lamp, or similar source, into a multiplicity of flexible macroscopic light guides. The combination of the several elements of the inventive system results in a very efficient transfer of the energy of the light source to the light guides. Light from the lamp is fed to four or more ports, with each port having one or more flexible macroscopic light guides connected thereto.

Abstract: An optical power summing apparatus that allows a multiplicity of optical signals to be combined with minimal signal transmission loss. A single photodiode simultaneously receives all of the input signals to perform a summation of signal powers. Alternative embodiments of the apparatus use either a tightly packed bundle of etched optical fibers or a converging arrangement of optical waveguides on a dielectric substrate to focus the optical signals onto the base region of a single photodiode.

Abstract: A fiber-optic bandpass filter comprising a resonant cavity formed in an optical waveguide is coupled to a fiber-optic bus which carries a large number of frequency multiplexed channels. The fiber-optic bandpass filter is selected to be one-half the modulation wavelength of the desired center frequency within a range of frequencies carried on the same transmission. The creation of a resonant cavity at the desired center frequency provides a filter which reduces the intensity of signals at surrounding frequencies so that an overall reduced output power is provided, resulting in less cross-talk between a large number of frequency multiplexed signals which, unfiltered, would all have equal power. The filter is broad enough that many adjacent channels are not significantly attenuated. The optical waveguide of which the filter is formed may be in the form of an optical fiber segment or a planar waveguide.

Abstract: An optical modulator for generating an amplitude modulated optical signal. A signal generator generates an optical signal that is optically coupled to a tunable filter which shares a common optical axis with the signal generator. The tunable filter wavelength response varies in response to an electrical input control signal thereby providing an output amplitude modulated optical signal. An optical isolator is located between and shares a common optical axis with the signal generator and the tunable filter. The optical isolator is for preventing optical signals originating at the filter, traveling toward the signal generator, from impinging on the signal generator.

Abstract: An array of optical RF bandpass filters which is fabricated from planar waveguides on a single substrate. The array of filters receives an input of frequency multiplexed optical signals and separates the intensity modulated optical signal of the desired frequency from signals at other frequencies. Each bandpass filter comprises a resonant cavity formed from a segment of a planar optical waveguide with mirrors deposited at each end. By using ultra high purity CVD techniques common in the optical fiber industry, material absorption is dramatically reduced. Much thicker waveguides are grown than those conventionally fabricated, allowing the use of refractive index differences between waveguide and cladding which are much smaller than those normally used in planar waveguides. To enable the fabrication of a monolithic array of filters having differing center frequencies, the substrate is cut at an angle so that resonant cavities of different lengths are formed.

Abstract: A fiber optic power coupling device such as a power summer, power divider or star coupler comprises a segment of multimode optical fiber having an input mirror at one end and an output mirror at the opposite end. One or more inputs at the input end of the fiber segment direct an equivalent number of input, intensity modulated light signals into the fiber and one or more outputs at the output end direct a corresponding number of output signals out of the fiber. Where there is one input and a plurality of outputs, the device acts as a power divider. Where there are a plurality of inputs and one output, the device acts as a power summer. Where there are a plurality of inputs and a plurality of outputs, the device acts as a star coupler.

Abstract: A multiple pole optical bandpass filter comprises at least two input filter elements each having an input at one end and an output at the opposite end, and an output filter element having at least two inputs at one end coupled to the respective outputs of the input filter elements, and an output at the opposite end. Each of the filter elements comprises a segment of multimode optical fiber of predetermined length having mirrors at its opposite input and output ends. An intensity modulated light signal is provided at one of the input filter element inputs, while the same signal shifted by 180 degrees is provided at the other input filter element input.

Abstract: A system and method for detecting the positioning of an object wherein a driver generates an optical signal and intensity modulates the optical signal at a rate corresponding to the sum of N different frequencies. A transducer, responsive to relative physical positioning of the object, receives the intensity modulated optical signal and extracts a portion of the intensity modulated optical signal corresponding in intensity to selected ones of the N frequencies. A decoder, responsive to the extracted portion of the intensity modulated optical signal, generates a position signal according to the selected ones of the N frequencies in the extracted portion. The position signal is indicative of the relative positioning of the object with respect to the transducer.

Abstract: A fiber optic data bus that includes a multiplexer means for generating a plurality of optical signals and for intensity modulating each of the optical signals in response to a respective one of a plurality of input RF signals each at a different RF carrier frequency to provide a plurality of intensity modulated optical signals. A signal collection means combines the plurality of intensity modulated optical signals into a combined optical signal. A conducting means conducts the combined optical signal to a signal distribution means which distributes the combined optical signal to each of a plurality of output ports. A demultiplexer means extracts from a portion of one of the distributed combined optical signals an output RF signal substantially identical to a predetermined one of the plurality of RF input signals.

Abstract: A spectrum analyzer subsystem for analyzing the frequency content of an RF signal including an optical source means responsive to an RF signal for generating a plurality of intensity modulated optical signals and a filter means responsive to each one of the intensity modulated optical signals for providing a plurality of output optical signals each corresponding to a respective one of the intensity modulated optical signals. Each output optical signal corresponds in intensity to the frequency content of an RF signal within a different predetermined frequency bandwidth. Detector means, which is responsive to each output optical signal converts each output optical signal into a corresponding electrical signal.

Abstract: An optical RF bandpass filter employing a noncoherent optical carrier. The filter consists of a section of multimode optical fiber having a length equal to half the modulation wavelength with mirrors deposited at each end of the fiber. The fiber section functions as a resonant cavity for the intensity modulated light which is directed into the fiber and which exits at one end through one of the partially reflecting mirrors.