Abstract: An apparatus includes a stacked patch radiator having (i) a lower patch and (ii) an upper patch located above and separated from the lower patch. The upper patch includes first and second conductive patches that are separated from one another. The apparatus also includes a heating circuit integrated in the stacked patch radiator. At least a portion of the heating circuit is positioned between the first and second conductive patches of the upper patch. The stacked patch radiator can be configured to radiate at a specified frequency band and can have a thickness that is less than one tenth of wavelengths within the specified frequency band. The upper patch can include conductive vias electrically connecting the conductive patches. The conductive patches and the conductive vias can form an isolation cage configured to reduce a signal loss associated with a presence of at least the portion of the heating circuit between the conductive patches.

Abstract: A feed assembly for that operates at different frequency bands (e.g., low, mid and high frequency bands) is provided herein. The feed assembly includes a feed horn common to low, mid and high frequency bands, a coaxial polarizer to launch signals in the low band frequency band, a coaxial orthomode transducer (OMT) to launch signals in the low band frequency band and supports the mid and high frequency bands, and a polyrod disposed in a center conductor of the feed assembly, the polyrod common to the mid and high frequency bands. The feed assembly includes a tri-band feed assembly having different portions to support signals in the low frequency band and signals in the mid and high frequency bands.

Abstract: A radar system uses a rotating antenna array having rows that display dispersive properties while feeding multiple radiating elements. In some embodiments, the radiating elements are dual polarized. In at least one embodiment, beam spoiling may be used to generate an unfocused transmit beam that covers an entire elevation range of interest. Digital beam forming may be used during a receive mode to achieve a stack of narrow-width receive beams in elevation. Frequency scanning may also be used to achieve stacked beams in azimuth.

Abstract: An apparatus includes a stacked patch radiator having (i) a lower patch and (ii) an upper patch located above and separated from the lower patch. The upper patch includes first and second conductive patches that are separated from one another. The apparatus also includes a heating circuit integrated in the stacked patch radiator. At least a portion of the heating circuit is positioned between the first and second conductive patches of the upper patch. The stacked patch radiator can be configured to radiate at a specified frequency band and can have a thickness that is less than one tenth of wavelengths within the specified frequency band. The upper patch can include conductive vias electrically connecting the conductive patches. The conductive patches and the conductive vias can form an isolation cage configured to reduce a signal loss associated with a presence of at least the portion of the heating circuit between the conductive patches.

Abstract: A feed assembly for that operates at different frequency bands (e.g., low, mid and high frequency bands) is provided herein. The feed assembly includes a feed horn common to low, mid and high frequency bands, a coaxial polarizer to launch signals in the low band frequency band, a coaxial orthomode transducer (OMT) to launch signals in the low band frequency band and supports the mid and high frequency bands, and a polyrod disposed in a center conductor of the feed assembly, the polyrod common to the mid and high frequency bands. The feed assembly includes a tri-band feed assembly having different portions to support signals in the low frequency band and signals in the mid and high frequency bands.

Abstract: An antenna comprising a reflector have a center-fed shaped axially displaced elliptical (ADE) configuration with either an elliptical aperture or a truncated elliptical aperture is described.

Abstract: Methods and apparatus for a phase array radar system having a fragmented array. In one embodiment, subarrays forming a generally rectangular shape are disposed on the surface of a truncated cone or a dome so that gaps are formed between adjacent segments of subarrays or between every adjacent subarrays.

Abstract: A radar system uses a rotating antenna array having rows that display dispersive properties while feeding multiple radiating elements. In some embodiments, the radiating elements are dual polarized. In at least one embodiment, beam spoiling may be used to generate an unfocused transmit beam that covers an entire elevation range of interest. Digital beam forming may be used during a receive mode to achieve a stack of narrow-width receive beams in elevation. Frequency scanning may also be used to achieve stacked beams in azimuth.

Abstract: Methods and apparatus for combining radar signals of a two-dimensional primary radar covering a surveillance area and a passive adjunct radar to provide three-dimensional data for targets and weather. In exemplary embodiments, high beam and low beam data from the primary radar and elevation data from the adjunct radar can be used to mitigate interference from clutter, such as wind farms.

Abstract: An antenna comprising a reflector have a center-fed shaped axially displaced elliptical (ADE) configuration with either an elliptical aperture or a truncated elliptical aperture is described.

Abstract: A conformal hybrid elctro-optical/radio frequency (EO/RF) aperture including an optical phased array (OPA) in a center portion of the aperture, and a variable inclination continuous transverse stub (VICTS) RF antenna surrounding the OPA using a plurality of continuous transverse stub (CTS) subarrays.

Abstract: An integrated radio frequency (RF)/optical window includes an RF radome portion provided from a composite material substantially transparent to RF energy disposed about an optical window configured for use with an optical phased array.

Abstract: Methods and apparatus for a phase array radar system having a fragmented array. In one embodiment, subarrays forming a generally rectangular shape are disposed on the surface of a truncated cone or a dome so that gaps are formed between adjacent segments of subarrays or between every adjacent subarrays.

Abstract: Methods and apparatus for a feed assembly for a reflector antenna including an aperture common to low, mid, and high frequency bands, a polyrod design to launch signals in the mid and high frequency bands, a horn to launch signals in the low frequency band, a co-located phase center for launching signals in the low, mid, and high frequency bands, and a low-band monopulse array located on a surface about the aperture to track a satellite.

Abstract: A conformal hybrid elctro-optical/radio frequency (EO/RF) aperture including an optical phased array (OPA) in a center portion of the aperture, and a variable inclination continuous transverse stub (VICTS) RF antenna surrounding the OPA using a plurality of continuous transverse stub (CTS) subarrays.

Abstract: An array antenna is provided that operates at high-band and low-band, comprising a first array of high-band radiators and a second array of low-band radiators, each respective low-band radiator disposed so as to be interleaved between the high-band radiators so as to share an aperture with the high-band radiators. Each low-band radiator comprises a coaxial section, a dielectric section, a waveguide, and a planar section. The dielectric section is formed of a continuous piece of dielectric material and includes a hollow opening formed perpendicular to the coaxial section, and a plurality of step transitions, wherein at least one of the step transitions is disposed within and partially fills the waveguide operably coupled to the planar section. The planar section is oriented to the portion of high-band radiators such that the output of the respective low-band radiator is disposed between and within the spacing between adjacent high-band-radiators.

Abstract: An integrated radio frequency (RF)/optical window includes an RF radome portion provided from a composite material substantially transparent to RF energy disposed about an optical window configured for use with an optical phased array.

Abstract: Methods and apparatus for a feed assembly for a reflector antenna including an aperture common to low, mid, and high frequency bands, a polyrod design to launch signals in the mid and high frequency bands, a horn to launch signals in the low frequency band, a co-located phase center for launching signals in the low, mid, and high frequency bands, and a low-band monopulse array located on a surface about the aperture to track a satellite.

Abstract: An array antenna is provided that operates at high-band and low-band, comprising a first array of high-band radiators and a second array of low-band radiators, each respective low-band radiator disposed so as to be interleaved between the high-band radiators so as to share an aperture with the high-band radiators. Each low-band radiator comprises a coaxial section, a dielectric section, a waveguide, and a planar section. The dielectric section is formed of a continuous piece of dielectric material and includes a hollow opening formed perpendicular to the coaxial section, and a plurality of step transitions, wherein at least one of the step transitions is disposed within and partially fills the waveguide operably coupled to the planar section. The planar section is oriented to the portion of high-band radiators such that the output of the respective low-band radiator is disposed between and within the spacing between adjacent high-band-radiators.

Abstract: An extendable spar buoy sea-based communication system includes a spar buoy having a retracted configuration deployable from an underwater vessel and an extended configuration after deployment, and a communication subsystem mounted to the top of the spar buoy and supported thereby.