Abstract: A folded microstrip antenna for a flight aggregate or aircraft can be arranged around edges of thin structural parts, such as wings, tail units or control flaps, such that its surface is identical with the structure and folding takes place at the edge of the structure. The antenna is constructed such that its characteristic impedance is much higher at the folding edge than at ends of the structural antenna away from the edge. As a result, an approximately omnidirectional characteristic can be achieved.

Abstract: A GPS conformal adapted for use on a small diameter projectile. The antenna includes a GPS antenna array of six driven elements The antenna also has an antenna cover which includes a parasitic element aligned the six driven elements. The electric field coupling between the parasitic element and the driven elements produces an omnidirectional radiation pattern.

Abstract: A phased array antenna system for an aircraft which allows a beam from the antenna to be scanned down to or below the horizon when the aircraft is traveling at high latitudes. The system comprises a conformal phased array antenna aperture mounted on either a top, port or a starboard side of a fuselage of the aircraft, and at least one feedhorn mounted either in a blade secured to the fuselage or in a leading edge of a horizontal stabilizer of the aircraft. The feedhorn illuminates the conformal antenna aperture and the aperture projects a beam therefrom which can be more easily directed at targets at or below the horizon. The invention allows smaller antenna apertures to be used to scan a beam toward the horizon.

Abstract: A reflector for use under a radome disposed on a mobile platform such as an aircraft for reflecting a portion of the electromagnetic energy radiated by an antenna disposed under the radome such that the reflected portion of energy impinges the radome at an angle normal thereto, thereby reducing or eliminating further reflections of the reflected portion of energy within the radome toward the mobile platform on which the radome is mounted. In one preferred embodiment the radome includes a base portion which is covered with a cover of radar absorbing material (RAM). In another embodiment the radome includes a curved base portion which is adapted to match the curvature of the surface of the mobile platform on which the reflector is mounted.

Abstract: A reflector for use under a radome disposed on a mobile platform such as an aircraft for reflecting a portion of the electromagnetic energy radiated by an antenna disposed under the radome such that the reflected portion of energy impinges the radome at an angle normal thereto, thereby reducing or eliminating further reflections of the reflected portion of energy within the radome toward the mobile platform on which the radome is mounted. In one preferred embodiment the radome includes a base portion which is covered with a cover of radar absorbing material (RAM). In another embodiment the radome includes a curved base portion which is adapted to match the curvature of the surface of the mobile platform on which the reflector is mounted.

Abstract: According to one embodiment of the invention, an end-fire cavity slot antenna array structure includes an upper skin formed from a composite material corresponding to a outer surface of an aircraft wing a lower skin formed from a composite material corresponding to a portion of an inner surface of the aircraft wing and a plurality of proximately positioned electrically conductive elements disposed between the upper and lower skins. Each electrically conductive element is formed from at least one sheet of composite material having an electrically conductive surface, and the sheet of composite material is configured such that the electrically conductive surface defines an inside surface of the electrically conductive element and any outside surfaces of the electrically conductive element that are in contact with an adjacent electrically conductive element.

Abstract: In a system for providing data content to and from a plurality of mobile platforms where each of the mobile platforms transmits a return link having an EIRP to a predetermined location via a satellite-mounted transponder, a method for controlling an EIRP of the aggregate return link emissions of the mobile platforms. The method includes the steps of determining a probability distribution of the EIRP of the return link for each of the mobile platforms; and determining a probability distribution of the EIRP for the aggregate return link emissions using the probability distributions of the EIRP of the return link for each of the mobile platforms; determining an aggregate off-axis EIRP density envelope for a predetermined probability level and the probability distribution of the EIRP for the aggregate return link emissions.

Abstract: A fairing for use with a phased array antenna for attenuating the transverse magnetic (TM) electric field radiated by the antenna, to thereby reduce the possibility of interference with other transceivers operating in the area of the antenna but which are not the intended recipients of a signal transmitted by the antenna. The fairing is adapted to be secured to an outer surface of a fuselage of an aircraft and to support the phased array antenna thereon. The fairing includes a plurality of concentrically arranged channels that serve to capture and ground the TM electric field as it propagates along the plane of the fairing away from the phased array antenna. Advantageously, the phased array antenna is mounted on the fairing so that the fairing also acts as a heat sink to help cool the antenna. In one preferred form the fairing is made from aluminum.

Abstract: A munition article (11) is to be provided with an antenna (18) which, by virtue of a characteristic which is uniform all around, permits interference-free reception of items of satellite navigation information, even if in the manner of an artillery projectile (12) it is fired with spin along an elongate ballistic trajectory, so that a tail antenna with a spherical characteristic does not allow the expectation of good reception factors in relation to navigation satellites which are as high as possible above the horizon.

Abstract: The present invention relates to an atmospheric discharge protection arrangement in an antenna (10) arranged in communication with a hull of an aircraft (11), the antenna comprising a housing, consisting of at least a first side (14), a second side (15), a third side (16a) and a fourth side (16b), at least one of the third and fourth sides being at least transparent for electromagnetic waves. The protection arrangement is an internal protection arrangement comprising the first side (14) electrically coupled to the second side (15) through at least one antenna element (24), the first and second sides consisting of a conductive material, and that the second side being connected to hull of the aircraft (11).

Abstract: A testing apparatus for testing mobile telephones includes an antenna coupler, a holder and a testing device. The antenna coupler includes a printed circuit board upon one side of which is formed a slot antenna operative in a first frequency range and a dipole antenna operative in a second frequency range. The holder secures a mobile telephone under test in proximity to the antenna coupler. A coupler formed on a second side of the printed circuit board selectively supplies signals received by one of the antenna elements to the testing device. The testing device measures transmission and reception characteristics of the mobile telephone under test, including transmission phase error, frequency error, power and spectrum, and bit error rate.

Abstract: A Yagi antenna array is specifically designed for insertion in a thin wing leading edge radome. Tubular elements for driver, director components are inserted within the structural web of the radome and critical dimensions of antenna components, relative to wavelength, help achieve superior performance in the compact package.

Abstract: A compliant RF feed system (10) that provides impedance matching for VHF/AM, VHF/FM, UHF and L-band frequencies. The feed system (70) includes a feed post (14) electrically connected to an antenna element (18) at one end and a matching circuit package (22) at an opposite end, where the feed post (14) extends across a non-conductive gap (16) between the antenna element (18) and a conductive aircraft component (20). The matching package (22) includes a compressible bellows (38) mounted in the package (22), where the feed post (14) contacts the bellows (38) in a compression engagement to provide an electrical connection between the feed post (14) and a RF matching circuit (24) in the matching package (22). An impedance transformer (40) is provided in the matching package (22) to match the impedance of the bellows (38) to the matching circuit (24). The bellows (38) allows the electrical connection between the antenna element (18) and the aircraft component (20) to accommodate vibrations during aircraft operation.

Abstract: An aircraft mounted antenna system comprising a plurality of linear blade antenna arrays mounted on an upper portion of an aircraft fuselage. The blade arrays are symmetrically placed on the fuselage about a plane vertically bisecting the upper portion of the fuselage. The placement of the blade arrays is such that large scanning angle gain losses are minimized as the blade arrays on one side of the fuselage hand off the satellite tracking, acquisition, and communication to the blade arrays on the other side of the fuselage as the scanning angle increases.

Abstract: A multifunction antenna feed structure (30) that acts as a feed for a multibandwidth antenna system (22) used in connection with a modern tactical aircraft. The feed structure (30) includes a first feed (32) and a second feed (34) electrically connected to first and second feed points on an antenna element (24) at a location where the first feed (32) is impedance matched to the VHF/FM and UHF frequency bands and the second feed (34) is impedance matched to the VHF/AM frequency band. The first and second feeds (32, 34) are positioned within a flared notch (28) between the antenna element (24) and a conductive aircraft structural component (26). The feeds (32, 34) can take on different geometrical configurations, such as cylindrical feeds, cone feeds or taper feeds. The feeds are (32, 34) electrically isolated from conductive aircraft component (26) and are electrically connected to a matching network (70, 80).

Abstract: A structural endcap antenna for a vertical tail of an aircraft. The endcap antenna comprises an outer skin having an inner surface and an antenna element disposed adjacent to the inner surface of the outer skin. The antenna element is in electrical communication with an RF signal source. Disposed adjacent to the antenna element is an inner support structure electrically bonded thereto. The antenna element and the inner support structure are excited by the RF signal source and provide structural support to the endcap antenna.

Abstract: Circuitry for adjusting the resonant frequency of an Yttrium-Iron-Garnet (YIG) filter in the first local oscillator of a receiver carried on a guided missile is shown to include the combination of a crystal oscillator which produces a pilot signal for tuning the YIG filter to a corresponding resonant frequency and a frequency adjusting arrangement for offsetting the resonant frequency of the YIG filter by a predetermined amount.

Abstract: An antenna for utilization in a fuse of an artillery shell or the like. The antenna includes a dielectric disk having upper and lower surfaces, a radiator disposed on the upper surface of the dielectric disk, a ground plane disposed on the lower surface of said dielectric disk, and a plurality of spaced apart apertures radially disposed through the dielectric disk for coupling the radiator to the ground plane.

Abstract: An antenna system structurally integrated into a load-bearing structural member of an aircraft, such as a wing (30), horizontal tail section (36), or vertical tail fin (20) in such a way as to cause practically no added aerodynamic drag and to add minimal weight to the aircraft. The antenna system includes a flared notch (22, 32, 34 or 38) of non-conductive material and an antenna feed (12) that excites conductive portions of the structural member on opposite sides of the notch at a selected feed point (40). The conductive portions of the structural member and other conductive portions of the entire aircraft are excited by signals applied to the antenna feed. As a result, the antenna performance provides high gain omnidirectionally, and supports both vertically and horizontally polarized communication functions over a wide range of VHF and UHF bands.

Abstract: An aircraft antenna system integrated into one or more walls of an equipment pod (12) mounted beneath an aircraft (10). The equipment pod (12) has at least one wall with an antenna notch built into it. The antenna notch is tapered or flared toward a wider opening and is bounded on each side by conductive portions of the same pod wall. Other walls of the pod (12) are made from conductive materials, which are in electrical contact with the aircraft structure. The equipment pod (12) provide multiple antenna structures for use in a variety of aircraft applications. Further, use of multiple pods (12) allows an aircraft to be more easily reconfigured for different missions by removing and replacing the equipment pod.

Abstract: An apparatus and method for exciting an antenna with dual frequency bands which comprises feeding a first channel of the antenna with a first signal in the VHF band such that a first current is established in a first direction resulting in a first polarization, feeding a second channel of the antenna with a second signal such that a second current is established in a second direction resulting in a second polarization, and isolating characteristics of the first channel from characteristics of the second channel and the characteristics of the second channel from the characteristics of the first channel such that both the first channel and the second channel are adapted to transmit and receive energy within the same antenna structure without appreciable coupling between the first channel and the second channel.

Abstract: Apparatus which overcomes the blockage effect of an object in the path of a beam of RF energy, includes a conformal array of parasitic electrical conductor elements having a length of about .lambda./3 and which are selectively located above the surface of the object, also at a height of about .lambda./3. The parasitic conductor elements operate to duct the RF energy of the beam around the object with minimal loss in gain and effect on the beam's radiation pattern.

Abstract: A glide slope antenna for receiving information transmitted from the ground, including elevation guidance for the final approach. The glide slope antenna is integrated with the aft nose wheel well door and utilizes the inherent electrical properties associated with the graphite/epoxy composite door.

Abstract: A radar antenna system, adapted to be supported on an aircraft for surveillance, employs a nonconducting disk radome structured with aerodynamic fairing and otherwise to produce relatively low aerodynamic drag. A plurality of struts are used to secure the disk radome to the aircraft with the disk radome generally extending in a solid horizontal reference plane. A plurality of elongated, relatively low gain radiating elements are supported by a ground-plane box within the disk radome, with the radiating elements distributed across the disk radome and disposed to radiate generally in the vertical direction. An electronic system is supported within the ground-plane box, and it includes respective transmit/receive circuits which send and receive radio frequency signals to and from the radiating elements. Power cables extend through the struts to couple signals between the electronic system in the disk radome and radar system level circuitry located externally of the disk radome.

Abstract: A common aperture, dual mode semi-active laser (SAL) and millimeter wave (MMW) sensor having transreflector configured to allow transmission of SAL energy therethrough, a separator and a fresnel lens configured to pass MMW energy therethrough and to focus SAL energy passing therethrough, the separator being configured to separate SAL energy from MMW energy, and a twist reflector positioned in alignment with the transreflector, configured to rotate the polarization of the MMW energy such that, for received MMW energy, the twist reflector reflects and rotates the received MMW energy toward the transreflector, which reflects it onto a feed and comparator, and for transmitted MMW energy, the transreflector reflects toward the twist reflector, whereupon polarization of the transmitted MMW energy is rotated and reflected therefrom to then pass through the transreflector.

Abstract: The objective of the invention is to compensate for the attenuation, in a direction (X,X), of the radiation from an antenna (5) mounted on a helicopter (1), including elements (12) which disturb the propagation of electromagnetic waves. According to the invention, at least one conducting wire (14) is fixed on the structure (1) of said helicopter, in proximity to said antenna (5), and positioned so that the electromagnetic interaction between said antenna (5) and said conducting wire (14) at least partially compensates for said attenuation of radiation.

Abstract: A flat antenna array includes a screen plate, a conductive aperture plate which overlies the screen plate, and a dielectric sheet which is located between the aperture plate and the screen plate. Apertures in the screen plate define the locations of waveguides. A network of conductors is carried on the dielectric sheet. The conductors include stimulating elements which are aligned with the apertures. Each stimulating element includes first and second probes which have axes which cross each other and constitute a probe pair. A plurality of reflective elements are located above the dielectric sheet at locations which correspond to the apertures. A first output circuit connects together the first probes, a second output circuit connects together the second probes.

Abstract: A radar for an aircraft (1) comprises end-plates (4a, 4b) mounted at the tip's of two pairs of aircraft wings (2a, 2b, 3a, 3b). Each end-plate carries a sideways-looking phased array (6) whose beam is unobstructed by aircraft structure. The array can be made to have a large area, thus producing a narrow beam, steerable over a large solid angle. In one embodiment, the end plates (4a, 4b) incorporate fins (5a, 5b) which replace the aircraft fin to afford lateral stability and control.

Abstract: A frequency-selective surface designed to transmit (allow to pass through) electromagnetic radiation around one or more predetermined transmission frequencies. The frequency-selective surface comprises at least two layers, whereby the outer layer is made up of at least one electromagnetic reflecting layer with a periodic pattern of conductive elements. The periodic pattern of conductive elements is made to have a reflection resonance frequency for electromagnetic radiation which is of the order of three times higher than the desired transmission frequency. The inner layer is placed at a suitable predetermined distance from the outer layer. The inner layer is made up of at least one electromagnetic transmitting layer having a periodic pattern of aperture elements. The periodic pattern of aperture elements is made in order to have a transmission resonance frequency for electromagnetic radiation which is substantially the same as the desired transmission frequency.

Abstract: An antenna system utilizing an electrically conductive portion (16) of an aircraft structure to radiate and receive very-high-frequency (VHF) and ultra-high-frequency (UHF) radio signals over a wide frequency range without the need for an active tuner to accommodate frequency changes. An antenna element (22) is housed in a tail fin endcap section (20) and is positioned and shaped to form an elongated notch (26) between one edge (24) of the element itself and one adjacent edge (18) of an electrically conductive tail fin (16). The notch (26) is uniform over part of its length and is flared to a wider spacing over the remainder of its length. A feed point (30) along the notch (26) is selected for optimum performance. Matching electronics (14) couple the antenna system to a transceiver (15), which can operate either in a VHF/FM band, or in a UHF band, or in a VHF/AM band. The antenna system provides relatively good gain over the frequency range and provides a practically omnidirectional radiation pattern.

Abstract: The invention provides an aero-optical turret assembly that provides high Strehl ratios throughout a wide range of azimuthal look angles. The turret assembly includes a duct extending from aft of the turret to a location aft of an aerodynamic bulge of the turret assembly. During flight, a low pressure zone is formed at the exit end of the duct, aft of the aerodynamic bulge. This low pressure zone causes suction of air from the inlet of the duct, and therefore away from the outer surfaces of the aero-optical turret. By judiciously selecting the shape of the aerodynamic bulge, and the size and location of the inlet end of the duct, substantially all turbulent air can be removed from around the adjacent outer surfaces of the aero-optical turret, thereby removing the source of interference with electromagnetic radiation passing through the window of the turret at azimuthal look angles greater than +60.degree..

Abstract: A fixed body wide field-of-view conformal antenna array suitable for broadband precision direction finding on missile platforms. The array is configured as multiple sub-arrays of spiral antennas that cover particular regions within the desired field-of-view of the entire array. A lower cost, more reliable and more accurate direction finding solution for missile needs is provided, primarily by the elimination of conventional radomes and antenna gimbal structures. The array can be configured to include multi-mode sensors.

Abstract: Disclosed is a combined antenna and helicopter rotor blade. The antenna has one or more electrically non-conductive rotor blades, each having an electrical conductor positioned parallel to the major axis of a respective rotor blade. An electrical connection is provided to connect the antenna to a radio for the reception or transmission of radio waves. Also disclosed is a communications system including apparatus for the transmission or reception of radio waves. Two of the electrical conductors, having angular positions nearer to a predetermined angular position are connected via the electrical connector to the radio. The remaining conductors may either be connected to the body of the helicopter or supplied with a signal out of phase compared to that supplied to the two electrical conductors.

Abstract: Radomes having complexly curved, frequency selective surfaces are made with a high degree of precision to assure part-to-part uniformity in electrical performance using a three-dimensional conformal mask and a precision etch process. The mask has a transparent substrate and a patterned opaque layer on the substrate. We expose photosensitive material overlying a thin film metal layer (generally deposited on a dielectric) through the mask. Metal exposed by patterning the photosensitive material is etched with a CuCl.sub.2 and chloride salt solution, and the remainder of the layer of photosensitive material is removed to complete the patterning.

Abstract: A combination antenna for aircraft and the like capable of transmitting and receiving VHF signals and receiving GPS signals comprising a VHF monopole antenna assembly and a GPS patch antenna assembly located within a common aerodynamically shaped dielectric housing. Separate connectors connect coaxial cables to the two assemblies and assembly elements are provided to suppress cross coupling of signal harmonics and noise from the transmitted VHF signals to enhance isolation of the received signals for the GPS and VHF functions. No adding or separation of the VHF and GPS signal information is required and the low patch antenna profile enables a low and aerodynamically shaped antenna for the beneficial use on small aircraft.

Abstract: Parts having complexly curved, frequency selective surfaces can be manufactured with a high degree of precision using a three-dimensional conformal mask. The mask has a transparent substrate and a patterned opaque layer on the substrate. The layer may be patterned by laser ablation. Alternatively, the patterning of the opaque layer can be accomplished by applying a layer of photosensitive material over the opaque layer and then defining temporary and permanent areas thereof. The temporary areas of the photosensitive layer and the opaque layer are removed sequentially to define the transparent portions of the mask. Parts are made by intimately mating the mask and a part body to which a layer of metal and a layer of photosensitive material have been applied, and exposing the part to radiation through the mask. The exposed part is then chemically developed, the layer of metal is etched, and the remainder of the layer of photosensitive material is removed to complete the patterning of the part body surface.

Abstract: Signal antennae are mounted on the casing wall between forward nose and r tail ends of an aerospace launched vehicle for radio communication through a radiation conducting sheath of plasma formed thereon by atmospheric ionization during descent of the vehicle along a non-gliding reentry path. The reentry path is maintained by vehicle guidance at a steep angle in response to data transmitted to the antennae through the radiation conducting sheath having a plasma content minimized by cooling which is thereby maintained in complete surrounding relation to the vehicle and modulated to enhance data transmission during the entire duration of vehicle descent.

Abstract: Internal conformal antenna arrays are mounted in aircraft aerosurface and fuselage primary and secondary load carrying structures. These radar transmitting structures are dual role structures capable of efficiently transmitting and receiving radio frequency energy, and efficiently carrying and transmitting aerodynamic loads. The internal conformal antenna arrays are mounted in the leading and trailing edges of the wings, in the empennage, and behind the outer shell of the fuselage. In order to achieve radar transmitting structures capable of transmitting radio frequency energy and meeting primary aerodynamic load carrying requirements, ceramic, quartz, or silicone-carbide fiber-reinforced organic matrix composites are combined with advanced structures technology.

Abstract: Parts having complexly curved, frequency selective surfaces can be manufactured with a high degree of precision using a three-dimensional conformal mask. The mask has a transparent substrate and a patterned opaque layer on the substrate. The layer may be patterned by laser ablation. Alternatively, the patterning of the opaque layer can be accomplished by applying a layer of photosensitive material over the opaque layer and then defining temporary and permanent areas thereof. The temporary areas of the photosensitive layer and the opaque layer are removed sequentially to define the transparent portions of the mask. Parts are made by intimately mating the mask and a part body to which a layer of metal and a layer of photosensitive material have been applied, and exposing the part to radiation through the mask. The exposed part is then chemically developed, the layer of metal is etched, and the remainder of the layer of photosensitive material is removed to complete the patterning of the part body surface.

Abstract: A fiber optic transmitter/receiver module used for controlling multi-axis beam steering of each individual radiating element in a phased array antenna and which is an integral part of a reconfigurable fiber optic corporate feed concept. In the receive mode of operation an incoming signal is captured, amplified and converted into the light domain by means of optical heterodyning. The relative phase and amplitude of the signal would be controlled by optically adjusting the amplitude and phase of a local oscillator. The local oscillator is sent to each fiber optic transmitter/receiver module. In the transmit mode of operation a signal for transmission which is in the light domain is down converted into the electromagnetic domain using optical mixing techniques. Once again, the relative phase and amplitude of the transmission signal would be controlled by the local oscillator.

Abstract: A surface conforming sense antenna is integrated with the surface skin of an aircraft by removing a rectangular looped strip of a metallized exterior composite surface skin. The remaining interior metallized portion isolated from the exterior metallized section forms an antenna sense element. The inner metallized portion is connected to an ADF radio receiver to function as a sense antenna in conjunction with a loop antenna. The gap between the metallized inner portion of the exterior metallized section allows lightning energy to be discharged thereacross. The modification does not impose a weight penalty or a wind drag penalty and does not degrade lightning protection for the composite aircraft.

Abstract: A compact high frequency multi-turn loop antenna is provided for use on a conductive structure such as the airframe of an airborne vehicle. The antenna employs a plurality of interconnected conductive loops which are magnetically coupled to a conductive structure. One end of the conductive loops is coupled via tuning and impedance matching circuits to a transceiver for transmitting and receiving signals therefrom. The other end of the conductive loops is coupled to ground. When transmitting a signal, the transceiver excites a current on the conductor which induces a magnetic field that excites the conductive structure. Upon receiving a signal, the conductive structure is excited which in turn generates a magnetic field through the plurality of loops and induces a current on the conductor. The antenna may advantageously be mounted within a conductive cavity structure which in turn is connected to the conductive structure.

Abstract: A dual polarization antenna for use on an aircraft, preferably a helicopter or the like, permits practical and reliable high frequency radio communications in a severe non line of sight, nap of the earth flight environment. The antenna comprises both a horizontally polarized component and a vertically polarized component. The horizontally and vertically polarized components are formed of an integral element, which has a bend therein so that the two components have an angular orientation with respect to one another. The horizontally polarized component is oriented in a generally horizontal direction and the vertically polarized component is oriented in a generally vertical direction. Ideally, the horizontally and vertically polarized components are oriented as orthogonally to one another as possible, depending upon the airframe application.

Abstract: A switching device for adjusting the impedance of a self-inductance (3) forming part for example of the radiator of a VHF/UHF antenna for aircraft switchable by short-circuiting a part of the self-inductance. A PIN diode (12) is raised to a blocking or a transmitting voltage in response to control signals which are transmitted thereto by an optical link (8). Preferably the optical signals are transmitted to a hybrid opto-electronic circuit, which renders the PIN diode operative in conjunction with insulated conductors (11, 13) plated on the self-inductance and raised to the desired voltage.

Abstract: A microwave antenna capable of operating at high temperature comprises at least one waveguide opening to the outside through an opening in a covering panel and including a tubular portion integrally formed with the panel, projecting inwards therefrom, and connected to the remainder of the panel around the opening, the panel and the integrated waveguide being made of a refractory composite material capable of ensuring microwave propagation and constituting a structural element capable of being raised to high temperature. The waveguide is filled with a refractory dielectric material such as an alumina-alumina type composite material.

Abstract: A multimode low-profile avionics antenna is disclosed for use in Automatic Direction Finder (ADF) systems. The low profile antenna generates a steerable cardioid radiation pattern having a minimum bandwidth of 30% and an unusual degree of independence from mutual coupling and coupling to ground-plane currents. The antenna includes two resonant cavity-backed slot antennas. The upper cavity, which backs a directional crossed-slot antenna, is the larger of the two cavities. The shallow lower cavity is actually a short-circuited radial transmission line employing a stepped inner radius and band-switching to extend the operating bandwidth to the required 30%. The crossed-slot antenna elements are configured orthogonally and the slot ends are folded over the side of the cylindrical cavity to minimize the resonant cavity diameter for the requisite slot length.

Abstract: A folded broadband antenna provides a symmetrical radiation pattern comparable to corresponding planar antennas (such as a planar spiral). The folded antenna can be integrated into a leading edge radome, eliminating the forward antenna cavity, and thereby, eliminating the internal wall reflections that cause radiation pattern distortion. A broadband antenna (61/62), such as an archimedean spiral, is folded at an apex area (64) that includes a fold-slot (66). The fold-slot enhances flexure, and allows a center-feed balun shielding tube (84) to extend into close proximity to the antenna aperture (61) for increased balun shielding.

Abstract: A structurally-embedded electronics assembly is disclosed and includes an outer skin member which is lightly loaded structurally, a primary load-carrying member positioned inboard from the outer skin member, a core member positioned between the primary load-carrying member and the outer skin member, an intermediate skin member positioned between the outer skin member and the core member and an electronics structure positioned between a predetermined two of the members or intermingled with a predetermined number of the members set forth above which are adjacent each other. In another embodiment, a thermally conductive baseplate member is positioned inboard from the primary load-carrying member. In another embodiment, a vibration damping member is positioned inboard from the primary load-carrying member.

Abstract: An antenna which conforms to the surface of a spacecraft can be a thin slot antenna which can be formed to the shape of the craft in combination with a compact ground plane formed of T-shaped or L-shaped pieces.

Abstract: A supersonic aircraft or missile broad bandwidth antenna is provided. This antenna is constructed into a cavity created in the fuselage or wing of the aircraft and covered with a radome for flush mounting. The cavity comprises side walls and a bottom constructed of electrically conductive materials which are caused to be electrically excited by an antenna element located within the cavity. This antenna element, which is capable of broad bandwidth operation, is either passively or actively tuned. Active tuning is carried out by a logic converter circuit connected to the antenna from a communications transceiver.