Abstract: Methods and apparatus for a multilayer millimeter-wave window according to various aspects of the present invention operate in conjunction with a multilayer window that is substantially transparent to a passing millimeter-wave. The window may include multiple perforations in a thermally conductive element to be disposed in the path of the passing wave. A dielectric is positioned between each thermally conductive element and acts as a seal between wave source and an ambient environment. The window may also be configured to conform to a contoured surface or structure.

Abstract: A modular solid-state MMW power source based on a topology of the lens array amplifier provides both the flexibility to scale output power and effective thermal management. The modular power source includes a single submodule that uses one or more power dividers and one or more solid-state amplification stages to divide and amplify an RF input signal into R amplified RF signals. The submodule is mounted (suitably in the X-Y plane) on the surface of a heat sink, suitably coupled to a cold backplane, to remove heat. R 1:N low loss power dividers route the amplified RF signals to R*N radiating elements. Each of the 1:N power dividers suitably reside in the X-Z plane and are stacked in the Y direction to provide a planar output of the R*N radiating elements in the Y-Z plane. Placement of the amplifier chips on the single submodule decouples the number of amplifier chips, hence output power, from the number of radiating elements.

Abstract: An exemplary apparatus providing an antenna for radiating electromagnetic energy is disclosed as having: a first dielectric substrate having opposite first and second surfaces, a patch of conducting material disposed on the first surface, a ground plane of conducting material disposed of the second surface, at least three input means coupled to a plurality of microstrip feed lines wherein the microstrip feed lines have an aspect ratio suitably configured to maximize antenna bandwidth. Disclosed features and specifications may be variously controlled, adapted or otherwise optionally modified to improve and/or modify the performance characteristics of the antenna. Exemplary embodiments of the present invention generally provide an antenna for providing wideband power combining and wideband radiation functions.

Abstract: A foldable reflect array may include a plurality of geometrically-flat reflect antennas. Each of the reflect antennas may include a respective plurality of antenna elements to receive and retransmit an incident wavefront, and each of the plurality of reflect antennas may be foldably coupled to at least one other of the plurality of reflect antennas.

Abstract: A modular solid-state MMW power source based on a topology of the lens array amplifier provides both the flexibility to scale output power and effective thermal management. The modular power source includes a single submodule that uses one or more power dividers and one or more solid-state amplification stages to divide and amplify an RF input signal into R amplified RF signals. The submodule is mounted (suitably in the X-Y plane) on the surface of a heat sink, suitably coupled to a cold backplane, to remove heat. R 1:N low loss power dividers route the amplified RF signals to R*N radiating elements. Each of the 1:N power dividers suitably reside in the X-Z plane and are stacked in the Y direction to provide a planar output of the R*N radiating elements in the Y-Z plane. Placement of the amplifier chips on the single submodule decouples the number of amplifier chips, hence output power, from the number of radiating elements.

Abstract: There is disclosed an apparatus to test an antenna. A transmitter generates a test signal radiated by the antenna under test. A near field scanner includes a field sampling probe to capture electromagnetic energy radiated by an antenna under test. An x-y positioning system including x and y positioning motors moves the field sampling probe over a measurement surface disposed proximate to the antenna under test. A quasi-optical beam transport system couples at least a portion of the captured electromagnetic energy from the field sampling probe to a scanner output port. A receiver is coupled to the scanner output port.

Abstract: Methods and apparatus for a multilayer millimeter-wave window according to various aspects of the present invention operate in conjunction with a multilayer window that is substantially transparent to a passing millimeter-wave. The window may include multiple perforations in a thermally conductive element to be disposed in the path of the passing wave. A dielectric is positioned between each thermally conductive element and acts as a seal between wave source and an ambient environment. The window may also be configured to conform to a contoured surface or structure.

Abstract: An exemplary apparatus providing an antenna for radiating electromagnetic energy is disclosed as having: a first dielectric substrate having opposite first and second surfaces, a patch of conducting material disposed on the first surface, a ground plane of conducting material disposed of the second surface, at least three input means coupled to a plurality of microstrip feed lines wherein the microstrip feed lines have an aspect ratio suitably configured to maximize antenna bandwidth. Disclosed features and specifications may be variously controlled, adapted or otherwise optionally modified to improve and/or modify the performance characteristics of the antenna. Exemplary embodiments of the present invention generally provide an antenna for providing wideband power combining and wideband radiation functions.

Abstract: A foldable reflect array may include a plurality of geometrically-flat reflect antennas. Each of the reflect antennas may include a respective plurality of antenna elements to receive and retransmit an incident wavefront, and each of the plurality of reflect antennas may be foldably coupled to at least one other of the plurality of reflect antennas.

Abstract: Embodiments of active array antennas are generally described herein. Other embodiments may be described and claimed. In some embodiments, a reflect array antenna includes an array of rectangular monolithic sub-array modules arranged in a non-uniform pattern to leave a plurality of rectangular gaps in the pattern. A DC feed pin located within each gap may provide DC bias current to the sub-array modules. The sub-array modules may be mounted on a heat sink in the non-uniform pattern. The heat sink may have holes aligned with the gaps to allow passage of the DC feed pins. In some embodiments, an array cooling assembly may be coupled to the back of the heat sink to cool the reflect array antenna with a coolant.

Abstract: A system and method for combining and radiating electromagnetic energy. The invention includes a novel antenna comprising a first dielectric substrate having opposite first and second surfaces, a patch of conducting material disposed on the first surface, a ground plane of conducting material disposed on the second surface, and at least three input ports, each input coupled to the patch at a feed point. The feed points are positioned to minimize the total power reflected from each input port. In an illustrative embodiment, the feed points are equally distributed around a circle having the same center as the patch and having a radius chosen to minimize the reflections at each input. In accordance with the novel method of the present invention, the outputs of multiple sources are combined in the antenna itself, by coupling the sources directly to the antenna.

Abstract: An optically transparent dielectric reflector (200) that reflects an incident millimeter-wave beam at a design frequency. The reflector (200) includes layers of different optically transparent dielectric materials. The thickness of the individual layers is chosen so that the transmitted waves cancel almost completely in the forward direction, yielding a high degree of transmission loss and substantial reflection. In the preferred embodiment, the invention is comprised of alternating layers of optical sapphire and air. In the best mode, there are seven sapphire layers, with outer sapphire layers (50) having a nominal thickness of 70.8 mils, inner sapphire layers (52) with a nominal thickness of 30.4 mils, and air layers have a nominal thickness of 32.0 mils Vented metal spacers (54) are used to maintain optimal thickness of air layers.

Abstract: A flat metal plate (20) has a plurality of holes (50) that have a property that changes across the surface of the plate so that the flat plate (20) mimics the behavior of a curved wavefront transformer. The changing property can include a dimension, such as radius or depth, such that the holes (50) near the center of the plate (20) are smaller, for example, than the holes (50) further away from the center of the plate (20). The size of each hole (50) is a function of the local phase change imparted on an electromagnetic wave of a particular wavelength or frequency that hits the hole (50), plus the propagation phase change that occurs in the reflected wave exiting the hole (50) as it travels the distance between the hole (50) and the focal point.

Abstract: An optically transparent dielectric reflector (200) that reflects an incident millimeter-wave beam at a design frequency. The reflector (200) includes layers of different optically transparent dielectric materials. The thickness of the individual layers is chosen so that the transmitted wavbes cancel almost completely in the forward direction, yielding a high degree of transmission loss and substantial reflection. In the preferred embodiment, the invention is comprised of alternating layers of optical sapphire and air. In the best mode, there are seven sapphire layers, with outer sapphire layers (50) having a nominal thickness of 70.8 mils, inner sapphire layers (52) with a nominal thickness of 30.4 mils, and air layers have a nominal thickness of 32.0 mils Vented metal spacers (54) are used to maintain optimal thickness of air layers.

Abstract: A variable beamsplitter (10) for use with quasi-optical millimeter-wave beams. The beamsplitter (10) consists of a circular metal plate (20) into which a periodic array (30) of rectangular slots is cut. The plate (20) is arranged so that the incident millimeter-wave beam is incident at an angle of 45° relative to the surface of the plate (20). The polarization of the incident beam is parallel to the surface of the plate (20). When the orientation of the plate (20) is such that the electric field is perpendicular to the slots (i.e., the electric field is directed across the narrow dimension of the slots), the plate (20) transmits nearly 100% of the incident power. If the plate is rotated about its axis by 90° (while maintaining a 45° angle between the incident beam and the plate) so that the incident electric field is parallel to the slots, then the plate (20) transmits 0% and reflects nearly 100% of the incident power at an angle of 90° relative to the incident beam.

Abstract: A flat metal plate (20) has a plurality of holes (50) that have a property that changes across the surface of the plate so that the flat plate (20) mimics the behavior of a curved wavefront transformer. The changing property can include a dimension, such as radius or depth, such that the holes (50) near the center of the plate (20) are smaller, for example, than the holes (50) further away from the center of the plate (20). The size of each hole (50) is a function of the local phase change imparted on an electromagnetic wave of a particular wavelength or frequency that hits the hole (50), plus the propagation phase change that occurs in the reflected wave exiting the hole (50) as it travels the distance between the hole (50) and the focal point.

Abstract: A variable beamsplitter (10) for use with quasi-optical millimeter-wave beams. The beamsplitter (10) consists of a circular metal plate (20) into which a periodic array (30) of rectangular slots is cut. The plate (20) is arranged so that the incident millimeter-wave beam is incident at an angle of 45° relative to the surface of the plate (20). The polarization of the incident beam is parallel to the surface of the plate (20). When the orientation of the plate (20) is such that the electric field is perpendicular to the slots (i.e., the electric field is directed across the narrow dimension of the slots), the plate (20) transmits nearly 100% of the incident power. If the plate is rotated about its axis by 90° (while maintaining a 45° angle between the incident beam and the plate) so that the incident electric field is parallel to the slots, then the plate (20) transmits 0% and reflects nearly 100% of the incident power at an angle of 90° relative to the incident beam.

Abstract: A millimeter-wave window is constructed from a high conductivity metal plate. The metallic plate is made transparent over a range of frequencies by perforating it with a periodic array of slots. In one embodiment, the millimeter-wave window is used in a gyrotron as the output window. In such a case, one suitable periodic array of slots comprises an equilateral triangular array of slots for operation at 95 GHz. By proper choice of the hole spacing and diameter, the window can be made transparent at any desired frequency. In addition to being transparent, however, the window must also be vacuum tight, as the pressure inside a gyrotron is on the order of 10−9 torr. The present invention solves this problem by covering the surface of the window with a thin layer of a suitable dielectric material, such as fused quartz.

Abstract: A millimeter-wave window is constructed from a high conductivity metal plate. The metallic plate is made transparent over a range of frequencies by perforating it with a periodic array of slots. In one embodiment, the millimeter-wave window is used in a gyrotron as the output window. In such a case, one suitable periodic array of slots comprises an equilateral triangular array of slots for operation at 95 GHz. By proper choice of the hole spacing and diameter, the window can be made transparent at any desired frequency. In addition to being transparent, however, the window must also be vacuum tight, as the pressure inside a gyrotron is on the order of 10−9 torr. The present invention solves this problem by covering the surface of the window with a thin layer of a suitable dielectric material, such as fused quartz.

Abstract: A high power TM01 mode radio frequency antenna. The inventive antenna comprises a conical horn for receiving an electromagnetic input signal and radiating an output signal in response thereto. An inner window is disposed within the conical horn. An outer window is mounted at an output aperture of the conical horn in alignment with the inner window. The antenna has a gradual taper from a waveguide input to the aperture over a cone angle of 45 degrees. The outer window is mounted at the aperture in concentric alignment with the inner window. For an optimal compact design, the inner and outer windows are of polycarbonate construction.