Abstract: Systems and methods for storing post-climacteric fruit are described. The system is scalable for home or commercial use and extends the storage life of fruit sensitive to over-ripening and spoilage because of the emission of ethylene gas. The described systems circulate and remove the ethylene gas, emitted by the fruit, from within an enclosure containing the fruit. Also, the system may store the fruit at an average temperature that extends the storage life of the fruit. The systems accomplish these objectives by thermally cycling the temperature of the air/gas within the enclosure containing the fruit about a desired storage temperature. The change in temperature may cause the air to expand and contract. Mechanisms allow the expanding and contracting air to exchange the gas within the enclosure with the air outside the enclosure, inducing the flushing of the ethylene gas.

Abstract: Systems and methods for storing post-climacteric fruit are described. The system is scalable for home or commercial use and extends the storage life of fruit sensitive to over-ripening and spoilage because of the emission of ethylene gas. The described systems circulate and remove the ethylene gas, emitted by the fruit, from within an enclosure containing the fruit. Also, the system may store the fruit at an average temperature that extends the storage life of the fruit. The systems accomplish these objectives by thermally cycling the temperature of the air/gas within the enclosure containing the fruit about a desired storage temperature. The change in temperature may cause the air to expand and contract. Mechanisms allow the expanding and contracting air to exchange the gas within the enclosure with the air outside the enclosure, inducing the flushing of the ethylene gas.

Abstract: A coaxial polarizer is provided. The coaxial polarizer includes an outer-conductive tube, an inner-conductive tube positioned within and axially aligned with the outer-conductive tube, and two dielectric bars each having a flat-first surface. The inner-conductive tube has two shallow-cavities on opposing portions of an outer surface of the inner-conductive tube. The shallow-cavities each have at least one planar area having a cavity length parallel to a Z axis and a cavity width, including a minimum width, perpendicular to the Z axis and to a radial direction of the inner-conductive tube. The flat-first surface has a dielectric length and width that are parallel and perpendicular to the Z axis, respectively. The dielectric length and dielectric width are less than the cavity length and the minimum width, respectively. The two flat-first surfaces of the respective two dielectric bars contact at least a portion of the respective two planar areas of the two shallow-cavities.

Abstract: In some examples, a device includes a waveguide transition section comprising a first mode suppressor, an attenuation section coupled to the first waveguide transition section via a first adjustable rotation joint, wherein the attenuation section is operable to attenuate the electromagnetic signal, and a first quarter-wave plate section coupled to the attenuation section, wherein the first quarter-wave plate section is operable to introduce a first differential phase shift between a first mode of the electromagnetic signal and a second mode of the electromagnetic signal. The device also includes a second quarter-wave plate section coupled to the first quarter-wave plate section via a second adjustable rotation joint, wherein the second quarter-wave plate section is operable to introduce a second differential phase shift between the second mode of the electromagnetic signal and the first mode of the electromagnetic signal.

Abstract: Turnkey maintenance of a customer's aircraft fleet is managed by a single management service provider (MSP) controlling integrated maintenance and materials services from a central operations site. The MSP converts data received directly from on-board aircraft systems into information it uses to manage maintenance service providers and parts suppliers. The MSP contracts with and manages maintenance, repair and overhaul organizations (MROs) who perform the maintenance on the customers' aircraft at line and base stations. The MSP either remotely manages part inventories at the customer's site, or manages suppliers who deliver the parts to the MROs. Maintenance planning, scheduling and execution information is exchanged between the MSP, MROs, part suppliers and the customers through a shared data communication network controlled by the MSP. The MSP charges the customer for the maintenance services based on a flat rate per unit of aircraft flying time.

Abstract: A compact interfacing device for rotating electro-magnetic fields between an input and output waveguide includes a support bar extending between opposing sides of a frame, the frame encircling an interior space divided by the support bar; and a dipole bar orientated orthogonal to the support bar. When the input waveguide interfaces an input-side of the frame and is arranged so that an extent of an input width of the input waveguide is orientated at first angle with respect to an extent of the dipole-bar length, and when the output waveguide interfaces an output-side of the frame and is arranged so that an extent of an output width of the output waveguide is orientated at a second angle with respect to the extent of the dipole-bar length, an input electric field aligned perpendicular to the extent of the input width is rotated upon propagating through the compact interfacing device.

Abstract: A waveguide-configuration adapter is provided. The waveguide-configuration adapter includes a horizontal waveguide and a vertical waveguide. The horizontal waveguide includes a first-interface port spanning a first X-Y plane and a first-coupling port spanning a Y-Z plane with a first-coupling-port width parallel to the y axis. The vertical waveguide includes a second-interface port spanning a second X-Y plane and a second-coupling port spanning a third X-Y plane with a second-coupling-port width parallel to the x axis. When an E-field is input at the first/second coupling port in the plane of the first/second coupling port, respectively, and oriented perpendicular to the first/second coupling-port width, respectively, the E-field is output from the second/first coupling port, respectively, in the plane of second/first coupling port, respectively, and oriented perpendicular to the second/first coupling-port width, respectively.

Abstract: In some examples, a device includes a waveguide transition section comprising a first mode suppressor, an attenuation section coupled to the first waveguide transition section via a first adjustable rotation joint, wherein the attenuation section is operable to attenuate the electromagnetic signal, and a first quarter-wave plate section coupled to the attenuation section, wherein the first quarter-wave plate section is operable to introduce a first differential phase shift between a first mode of the electromagnetic signal and a second mode of the electromagnetic signal. The device also includes a second quarter-wave plate section coupled to the first quarter-wave plate section via a second adjustable rotation joint, wherein the second quarter-wave plate section is operable to introduce a second differential phase shift between the second mode of the electromagnetic signal and the first mode of the electromagnetic signal.

Abstract: A compact interfacing device for rotating electro-magnetic fields between an input and output waveguide includes a support bar extending between opposing sides of a frame, the frame encircling an interior space divided by the support bar; and a dipole bar orientated orthogonal to the support bar. When the input waveguide interfaces an input-side of the frame and is arranged so that an extent of an input width of the input waveguide is orientated at first angle with respect to an extent of the dipole-bar length, and when the output waveguide interfaces an output-side of the frame and is arranged so that an extent of an output width of the output waveguide is orientated at a second angle with respect to the extent of the dipole-bar length, an input electric field aligned perpendicular to the extent of the input width is rotated upon propagating through the compact interfacing device.

Abstract: A waveguide-configuration adapter is provided. The waveguide-configuration adapter includes a horizontal waveguide and a vertical waveguide. The horizontal waveguide includes a first-interface port spanning a first X-Y plane and a first-coupling port spanning a Y-Z plane with a first-coupling-port width parallel to the y axis. The vertical waveguide includes a second-interface port spanning a second X-Y plane and a second-coupling port spanning a third X-Y plane with a second-coupling-port width parallel to the x axis. When an E-field is input at the first/second coupling port in the plane of the first/second coupling port, respectively, and oriented perpendicular to the first/second coupling-port width, respectively, the E-field is output from the second/first coupling port, respectively, in the plane of second/first coupling port, respectively, and oriented perpendicular to the second/first coupling-port width, respectively.

Abstract: A balun is a device for coupling together balanced and unbalanced electrical signals. An ultra-wide bandwidth balun can operate in a frequency band of more than 1.5 GHz to 26.5 GHz. The balun can be based upon a resistively loaded choke structure. The loading can be in the form of resistive cards or vanes. The vanes may be aligned with the electric field between the choke and an outer ground to prevent effective short circuits at points where the choke is half wavelength multiples in length. The resistive loading may also suppress higher order modes within the choke structure. The wideband balun can be very small to satisfy the tight space constraints of many modern communication applications. The balun may be fabricated using standard printed circuit board manufacturing techniques which may dramatically reduce production costs.

Abstract: A compact circular waveguide system can connect circular waveguides through a bend while avoiding excessive interaction between the orthogonal modes of the circular waveguides. A compact bend system with circular waveguide input and output can be achieved by providing short quarter wave transformers. The quarter wave transformers can be positioned at the transitions between the circular waveguides and a single-mode quasi-rectangular waveguide segment. Within the single-mode quasi-rectangular waveguide segment, a bend can be formed without concern for mixing of the orthogonal modes of the circular guided wave. The undesired mode of propagation can be substantially reduced or eliminated within the quarter wave transformers with a resistive mode suppressor. The compact system can be machined out of a single block of material from the outside flange faces.

Abstract: A compact circular waveguide system can connect circular waveguides through a bend while avoiding excessive interaction between the orthogonal modes of the circular waveguides. A compact bend system with circular waveguide input and output can be achieved by providing short quarter wave transformers. The quarter wave transformers can be positioned at the transitions between the circular waveguides and a single-mode quasi-rectangular waveguide segment. Within the single-mode quasi-rectangular waveguide segment, a bend can be formed without concern for mixing of the orthogonal modes of the circular guided wave. The undesired mode of propagation can be substantially reduced or eliminated within the quarter wave transformers with a resistive mode suppressor. The compact system can be machined out of a single block of material from the outside flange faces.

Abstract: A balun is a device for coupling together balanced and unbalanced electrical signals. An ultra-wide bandwidth balun can operate in a frequency band of more than 1.5 GHz to 26.5 GHz. The balun can be based upon a resistively loaded choke structure. The loading can be in the form of resistive cards or vanes. The vanes may be aligned with the electric field between the choke and an outer ground to prevent effective short circuits at points where the choke is half wavelength multiples in length. The resistive loading may also suppress higher order modes within the choke structure. The wideband balun can be very small to satisfy the tight space constraints of many modern communication applications. The balun may be fabricated using standard printed circuit board manufacturing techniques which may dramatically reduce production costs.

Abstract: The antenna includes an antenna body, comprising a conductive material, having a cavity surrounded by intersecting wall segments. The wall segments include a rear plate and a face plate having a planar array of longitudinal slots, and both plates are positioned in spaced-apart parallel planes. The antenna further includes a center wall, centrally placed between the face plate and the rear plate, to form within the cavity a parallel pair of waveguide channels. The center bar has a center bar opening extending longitudinally along a portion of the center bar, thereby separating the center bar portion into first and second center bar segments. A guidance hole is aligned with an edge of the center bar and extends through the first center bar segment and at least a portion of the second center bar segment. A probe distributes radio frequency (RF) energy in substantially equal phase and amplitude to the waveguide channels via the center bar opening.

Abstract: An antenna comprising a waveguide component and a probe assembly, coupled to the antenna assembly, for distributing radio frequency (RF) energy to slots positioned on at least one of the broad walls of the waveguide component. The probe assembly can be positioned at the approximate center point of the waveguide component to present a desired impedance to the waveguide cavity and to distribute RF energy of substantially equal amplitude and phase to each section of the waveguide cavity. The probe assembly includes a post, connected to one or both of the rear and front walls, and a probe pin. The post, which is typically positioned within the center of the waveguide cavity, comprises (1) a post cavity located within and extending along at least a portion of the post, and (2) a post slot having an opening located along the post and traversing the post cavity.

Abstract: Impedance matching between a waveguide circulator and its input/output ports is achieved by properly dimensioning a gap formed between a ferrite circulator element inside the waveguide circulator and at least a portion of the input/output port aperture itself. Typically, the I/O port aperture has at least a portion which is of lesser height dimension than the internal waveguide circulator cavity. Ridge waveguide or ridge-to-rectangular waveguide adaptor blocks, or the like, may emanate from such input/output circulator apertures.

Abstract: A conductive waveguide structure has a central cavity of full height and input/output ports of a second reduced height emanating therefrom. A smaller ferrite circulator element is centrally disposed within the cavity and has outer extremities spaced from the inner edges of the reduced height input/output ports by a predetermined gap dimension "G" which is chosen to achieve an appropriate impedance match between the impedance of the ferrite element and the higher impedance of the wavguide without the necessity for the usual quarter-wave dielectric impedance matching transformer sections.

Abstract: A compact adaptor is provided for making transition from ridged waveguide to rectangular waveguide while simultaneously imparting spatial reorientation of associated electric and magnetic fields. The adaptor is especially useful for feeding a phased array of radiating slots (or other structures) where adjacent radiating structures are preferably spaced from one another on the order of a half wavelength and fed with the magnetic field vectors oriented parallel to such inter-element array spacing dimensions. In the exemplary embodiment, a transition from double-ridged waveguide to rectangular waveguide is effected through an electrically short (e.g., 1/8th to 1/4th wavelength) non-resonant cavity using oppositely tapered continuations of the ridged waveguide walls (acting as a TEM parallel transmission line) to opposing walls of a rectangular waveguide port which is spatially oriented transverse to the ridged waveguide.