Abstract: An antenna includes a plurality of waveguide antenna elements arranged in a first array configured to operate with a first polarization. The antenna also includes a plurality of waveguide output ports arranged in a second array configured to operate with a second polarization. The second polarization is different from the first polarization. The antenna further includes a polarization-modification layer with channels defined therein. The polarization-modification layer is disposed between the waveguide antenna elements and the waveguide output ports. The channels are oriented at a first angle with respect to the waveguide antenna elements and at a second angle with respect to the waveguide output ports. The channels are configured to receive input electromagnetic waves having the first polarization and transmit output electromagnetic waves having a first intermediate polarization.

Abstract: A device is provided that includes a first platform having a first side, and a second platform having a second side positioned within a predetermined distance to the first side. The device also includes an actuator configured to cause a relative rotation between the first platform and the second platform such that the first side of the first platform remains within the predetermined distance to the second side of the second platform. The device also includes a probe mounted to the first platform, and a plurality of probes mounted to the second platform. The device also includes a signal conditioner coupled to the plurality of probes. The signal conditioner may select one of the plurality of probes based on an orientation of the first platform relative to the second platform. The signal conditioner may then to use the selected probe for wireless communication with the probe on the first platform.

Abstract: An antenna includes a plurality of waveguide antenna elements arranged in a first array configured to operate with a first polarization. The antenna also includes a plurality of waveguide output ports arranged in a second array configured to operate with a second polarization. The second polarization is different from the first polarization. The antenna further includes a polarization-modification layer with channels defined therein. The polarization-modification layer is disposed between the waveguide antenna elements and the waveguide output ports. The channels are oriented at a first angle with respect to the waveguide antenna elements and at a second angle with respect to the waveguide output ports. The channels are configured to receive input electromagnetic waves having the first polarization and transmit output electromagnetic waves having a first intermediate polarization.

Abstract: An access control system includes a mesh network of nodes for tracking and authenticating users throughout a building. The nodes include wireless interfaces. The user devices send user information to the nodes, which send the user information to a verification and tracking system, which returns authentication status information. As the user moves throughout the building, the nodes calculate the proximity between the particular node and the user device and compare the calculated proximity information to that of nearby nodes. The user information and authentication status information is then handed off to the node determined to be closest to the user device and, in the case of door nodes connected to door controllers, is used to grant access to restricted areas of the building. Door nodes are equipped with directional antennas with an adjustable antenna assembly including two or more probes to eliminate dead zones around the door nodes.

Abstract: A rotary coupling includes a first waveguide, a second waveguide that is coaxial with the first waveguide and supported for rotation relative to the first waveguide, and a collar. The collar is connected to one of the first and second waveguides and extends circumferentially about an end of the other of the first and second waveguides to reduce attenuation of electromagnetic radiation conveyed between the first waveguide and the second waveguide.

Abstract: Aspects of the subject disclosure may include, for example, a transmission medium that includes a dielectric core comprising a plurality of rigid dielectric members configured to propagate guided electromagnetic waves. A dielectric cladding is disposed on at least a portion of an outer surface of the first dielectric core. Other embodiments are disclosed.

Abstract: A device is provided that includes a first platform having a first side, and a second platform having a second side positioned within a predetermined distance to the first side. The device also includes an actuator configured to cause a relative rotation between the first platform and the second platform such that the first side of the first platform remains within the predetermined distance to the second side of the second platform. The device also includes a probe mounted to the first platform, and a plurality of probes mounted to the second platform. The device also includes a signal conditioner coupled to the plurality of probes. The signal conditioner may select one of the plurality of probes based on an orientation of the first platform relative to the second platform. The signal conditioner may then to use the selected probe for wireless communication with the probe on the first platform.

Abstract: The current invention, by using a plurality of conductive fiber brush bundles and a coaxial line to transfer RF signal(s) between relatively rotatable objects, creates easy-maintenance, long duration a RF rotary joint with soft contacting rotational interfaces. It consists of a stationary shield conductor assembly, a stationary core conductor assembly, a rotational shield conductor assembly with a tapered round head, a rotational core conductor assembly with a tapered round head, and rotational and stationary insulating assemblies with a central bore. Both stationary and rotational shield conductor assemblies having a conductive fiber brush bundle, which further containing a plurality of hair-thin conductive filaments to form a symmetrical flexible tube.

Abstract: To provide a millimeter waveband filter which can vary a resonance frequency in a wider band without causing deterioration of resonance characteristics due to leakage of electromagnetic waves. In a millimeter waveband filter 20, a first waveguides 22 and a second waveguide 24 are relatively moved to vary the interval between the electric wave half mirrors 30A and 30B, and the resonance frequency of a resonator formed between the mirrors varies to selectively transmit resonance frequency components. A groove 60 which has a length p along a longitudinal direction of the transmission line corresponding to a ¼ wavelength of electromagnetic waves to be a leakage prevention target is provided on the outside of the second waveguide 24 facing the inside of the first waveguide 22, thereby preventing leakage of electromagnetic waves from the gap between the first waveguide 22 and the second waveguide 24.

Abstract: A device is provided that includes a first platform having a first side, and a second platform having a second side positioned within a predetermined distance to the first side. The device also includes an actuator configured to cause a relative rotation between the first platform and the second platform such that the first side of the first platform remains within the predetermined distance to the second side of the second platform. The device also includes a probe mounted to the first platform, and a plurality of probes mounted to the second platform. The device also includes a signal conditioner coupled to the plurality of probes. The signal conditioner may select one of the plurality of probes based on an orientation of the first platform relative to the second platform. The signal conditioner may then to use the selected probe for wireless communication with the probe on the first platform.

Abstract: In a millimeter waveband filter, electric wave half mirrors are provided in transmission lines of a first waveguide configured to allow electromagnetic waves in a predetermined frequency range of a millimeter waveband to propagate in a TE10 mode and a second waveguide connected to the first waveguide in a state where one end of the second waveguide is inserted into the first waveguide, and the waveguides are relatively moved to vary the interval between the electric wave half mirrors, thereby changing a resonance frequency. The first waveguide is a square waveguide, and the second waveguide is a ridge waveguide in which the outside thereof is a rectangular shape at a predetermined interval with respect to the inside of the first waveguide and a sectional shape of a transmission line has a central portion having a height smaller than both side portions.

Abstract: A waveguide polarization rotator is provided as unitary body with a first bore; a diametral first septum of the unitary body extending between sidewalls of the first bore. The first septum is twisted between a first end of the first septum and a second end of the first septum. The waveguide polarization rotator may be further provided in a matrix configuration with a plurality of second bores each with a diametral second septum of the unitary body extending between sidewalls of the second bores; a longitudinal axis of the first bore and each of the second bores parallel to one another. The waveguide polarization rotator may be manufactured via injection molding, casting or the like.

Abstract: A waveguide rotary joint includes a first waveguide portion for receiving a microwave signal, a second waveguide portion for outputting the received microwave signal, and a conductive pin including a first end and a second end distal from the first end, the first end arranged in and RF coupled to the first waveguide, and the second end arranged in and RF coupled to the second waveguide, and a choke cavity is arranged between the first waveguide portion and the second waveguide portion. The first waveguide and the second waveguide are rotatable relative to each other about a longitudinal axis of the conductive pin.

Abstract: The present invention relates to a rotary joint for joining two waveguides for guiding electromagnetic waves, comprising a first portion adapted to receive a first waveguide, a second portion adapted to receive a second waveguide, and a third portion adapted for polarization rotation and arranged between the first portion and the second portion. The rotary joint is configured such that two portions selected from the group comprising the first portion, the second portion and the third portion are rotatable between at least two different angular positions around a central axis. Further, the rotary joint being configured to switch between a jointed state, in which the portions contact each other for electrical connection, and a non-jointed state. The present invention also relates to a method of operating such a rotary joint and a computer program and a computer readable non-transitory medium for implementing such a method.

Abstract: Certain embodiments of the invention may include systems and methods for providing a translating telemetry stationary antenna. According to an example embodiment of the invention, a method is provided for automatically aligning a stationary antenna with a corresponding rotor antenna. The method provides for mounting a stationary antenna with respect to a rotor antenna associated with a rotor. The method includes mounting a stationary antenna to an inner circumference of a support frame, mounting a plurality of radial air bearings to the support frame for maintaining radial alignment of the stationary antenna with respect to the rotor antenna, and mounting a plurality of axial air bearings to the support frame for maintaining axial alignment of the stationary antenna with respect to the rotor antenna.

Abstract: A dual mode rotary joint as described herein can be utilized in an electromagnetic communication system such as a radar system. The dual mode rotary joint can be used to rotatably couple an antenna architecture to its mounting structure. One embodiment of the dual mode joint includes a waveguide configured to propagate radio frequency (RF) signals, and endcaps coupled to the ends of the waveguide. Each endcap is reflective for RF signals and transmissive for optical signals.

Abstract: The present invention relates to a rotary joint for joining two waveguides for guiding electromagnetic waves, comprising a first portion adapted to receive a first waveguide, a second portion adapted to receive a second waveguide, and a third portion adapted for polarization rotation and arranged between the first portion and the second portion. The rotary joint is configured such that two portions selected from the group comprising the first portion, the second portion and the third portion are rotatable between at least two different angular positions around a central axis. Further, the rotary joint being configured to switch between a jointed state, in which the portions contact each other for electrical connection, and a non-jointed state. The present invention also relates to a method of operating such a rotary joint and a computer program and a computer readable non-transitory medium for implementing such a method.

Abstract: A waveguide in semiconductor integrated circuit is disclosed, the waveguide comprises a horizontal first metal plate, a horizontal second metal plate above the first metal plate, separated by an insulation material, and a plurality of metal vias positioned in two parallel lines, running vertically through the insulation material in contacts with both the first and second metal plates, wherein the first and second metal plates and the plurality of metal vias form a metal enclosure in a cross-sectional view that can serve as a waveguide.

Abstract: A mode transducer for converting an electromagnetic wave between TE1,0 and TM0,1 modes. A rectangular waveguide guides the wave while in TE1,0 mode and a circular waveguide guides the wave while in TM0,1 mode. The rectangular waveguide and the circular waveguide are joined by a chamber to form a right angle structure. The chamber particularly includes offset walls distended away from proximal portions of the rectangular waveguide to convert the electromagnetic wave between modes. Two of the mode transducers rotatably coupled with a suitable rotation mechanism may be used as a rotary waveguide joint.

Abstract: An array transmits a wide-band electric signal between at least two components disposed for rotation relative to each other. The components are provided with coupling surfaces that are maintained at a largely constant distance from each other via the rotary movement. The space between the coupling surfaces is predominantly filled with a dielectric material.

Abstract: The present invention aims at providing a rotary joint which is of a thin type and has broad band characteristics and which is low in loss and is excellent in power resistance as well. In order to attain the object, the rotary joint includes: first and second polarizers each having a common side terminal connected to a waveguide portion, and two branch side terminals through which two polarized waves orthogonal to each other inputted through the common side terminal are separately taken out; and the waveguide portion which has a rotatable connection portion, one end of which is connected to the common side terminal of the first polarizer and the other end of which is connected to the common side terminal of the second polarizer.

Abstract: A device for non-contact transmission of electrical signals or energy between two parts mobile relative to each other comprising electromagnetic near-field coupler elements on the two parts, wherein the coupler elements on at least one part form a cascade circuit terminated in a manner substantially free from reflection, and each coupler element is an independent resonance system having a resonance frequency higher than a highest frequency of wide-band signals to be transmitted. An alternatively structured device in which each coupler element on one part includes an element that resonates independently and has a resonance frequency approximately equal to the frequency of signals or energy to be transmitted including developments in which the coupler elements operate on differential signals, or analyzer means determine the spacing between the two parts, or at least one part comprises symmetrical lines for supplying differential energy signals to two coupler elements.

Abstract: The present invention aims at providing a rotary joint which is of a thin type and has broad band characteristics and which is low in loss and is excellent in power resistance as well. In order to attain the object, the rotary joint includes: first and second polarizers each having a common side terminal connected to a waveguide portion, and two branch side terminals through which two polarized waves orthogonal to each other inputted through the common side terminal are separately taken out; and the waveguide portion which has a rotatable connection portion, one end of which is connected to the common side terminal of the first polarizer and the other end of which is connected to the common side terminal of the second polarizer.

Abstract: An optical microwave package eliminates launching electrical modes into a microwave strip-line by forming a moat in a housing portion of the package to suppress microwave resonant energy. The moat can be filled with a conductive material to further suppress package resonances. Additionally, the bottom of a substrate positioned within the housing is isolated from any conductive metal to further suppress microwave resonant energy.

Abstract: A feed assembly waveguide interface (10) between an antenna (12) coupled onto an upright post (14) and an outdoor radio (16), comprising a feed tube (18) connected at a first end (20) to a sub-reflector (22) and a second end (24) having a waveguide output (26). A structure (28) is for affixing the feed tube (18) internally within the antenna (12), so that the second end (24) will extend outwardly from a rear wall (30) of the antenna (12). An assembly (32) for spring loading the feed tube (18) on the affixing structure (28) will allow the second end (24) to be forced outwardly away from the rear wall (30) of the antenna (12). When the outdoor radio (16) is mounted to the rear wall (30) of the antenna (12), a positive interface connection will be made between the outdoor radio (16) and the antenna (12), thus making a solid mechanical connection between the outdoor radio (16) and the antenna (12), as well as a proper electrical and environmental seal.

Abstract: A connecting joint for a radio frequency waveguide line comprises a tubular metallic braid wire shield connecting two beam line pipe ends thereby making the inside surface appear as a continuous beam tube. The metallic braid wire is secured within a bellows assembly that allows the connecting joint to expand or contract as is appropriate for changes in ambient conditions or conditions within the waveguide line. The connecting joint is capable of supporting either positive or negative pressure within the joint while the exterior of the joint may vary with ambient conditions.

Abstract: A rectangular waveguide rotary joint that allows limited mechanical rotation of two rectangular waveguides around a common longitudinal axis. The joint comprises a first rectangular waveguide having a first waveguide flange and a second rectangular waveguide having a second waveguide flange, wherein the second waveguide flange is disposed adjacent to the first waveguide flange with an air gap disposed therebetween. An RF choke is formed in the waveguide flanges for reducing RF leakage caused by the air gap, and a low friction spacer system for separating the first and second waveguides to maintain relative alignment of the waveguides during rotation and maintain a substantially constant separation between the waveguides. The waveguide rotary joint provides for a low voltage standing wave ratio (VSWR) and low insertion loss exhibited over a +/-30 degree rotation range.

Abstract: The rotor of the joint includes two rectangular waveguide ports, carrying two separate signals. The stator has two corresponding rectangular waveguide ports. The ports are coupled with a circular waveguide, which comprises two relatively rotatable stub-cylinders, disposed co-axially in-line on the axis of rotation. Signal A is transmitted through the circular waveguide, across the joint, in the TM01 propagation mode, while signal B is transmitted across the joint in the TE01 mode. These circular-symmetrical modes, with mutually orthogonal field distribution, are able to cut cross-talk interference, since the mode transducers of these modes maintain good mutual isolation, even though the signals are present together in the circular waveguide, and at the same or similar frequency. The TM01 mode (signal A) is excited, and received, by means of slots formed in the end wall of the circular waveguide stubs. The port for signal A communicates with the circular waveguide through the two slots.

Abstract: A coaxial-waveguide assemblage is disclosed herein of the invention includes a first coaxial transmission line having a first inner and a first outer conductor. The inventive assemblage further includes a waveguide electromagnetically coupled to the first coaxial transmission line, where an inner surface of the waveguide bounds a signal propagation space. The waveguide is also electromagnetically coupled to a second coaxial transmission having a second inner and a second outer conductor. The inner conductor of the second coaxial transmission line is disposed to rotate about a first vertical axis, thereby enabling the second coaxial transmission line to be connected to a rotating antenna. In a particular implementation the coaxial-waveguide assemblage is disposed within a rotary joint operative to couple electromagnetic energy between first and second signal ports.

Abstract: This microwave link connects a fixed set of electronic equipment to a mobile set of electronic equipment that can be shifted between two extreme positions, at least one of which is an operating position. The link is, for example, one between a radar transceiver and a radar antenna that can be retracted into a silo. It is constituted by a sequence of rigid rectangular waveguide elements hinged at their ends by means of hinges comprising at least one rotating connector formed by two rectangular-window flanges, fitted together and rotational movable with respect to each other. This rotational connector has two operational positions at 180.degree. with respect to each other where it can transmit microwave power and where the rectangular windows of its flanges coincide, and it assumes one of these operational positions when the movable electronic equipment is in the operating position.

Abstract: A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150.degree. C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide.

Abstract: A connecting element for waveguides includes two waveguide sections which are contacted with each other via a bent choke of two sections and mechanically connected so as to allow a longitudinal displacement, tilting and rotation relative to each other. One waveguide section is provided at its circumference with an axial annular groove extending radially outside the axial section of the choke and the second waveguide section is provided with a circumferential collar projecting at least in an axial direction and engaging in the annular groove.

Abstract: A waveguide twist includes at least three waveguide sections which are connected to each other and rotatable about their longitudinal axis usually by a same angle. Each waveguide section with the exception of the first waveguide section and the last waveguide section supports externally a lever which has two axial ends engaging in grooves of adjoining waveguide sections so as to be longitudinally displaceable to allow distribution of the total angle of rotation over the waveguide sections.

Abstract: A microwave collinear antenna array applicator for in situ or in vivo treatment of tumors and/or other materials by hyperthermia is disclosed. The array consists of a plurality of harmonically related resonant coaxial antenna elements connected electrically in series to provide uniform heating along the entire length of the array. At the distal end of the array, a resistor may be provided at the inner conductor for steering the heating pattern. At the proximal end of the array, an impedance matching dielectric structure is provided to enable maximum power transfer to the array and to minimize stray leakage currents along the outside of the coaxial transmission line. The array may be made longer or shorter without changing frequency and therefore, depth of penetration by simply adding or subtracting half-wave resonant elements or sections of coaxial transmission line. A lossy sleeve member may be provided around the applicator to provide a localized source of heat.

Abstract: A pivotal joint for waveguides provides a low-loss interface between two rigid waveguides at which relative movement can occur. The pivotal joint has two waveguide sections which are terminated in conical surfaces containing concentric chokes to minimize RF energy leakage. A universal gimbal is utilized to position the joints so that the pivotal motion occurs about the apices of the chokes. The advantages of this RF joint include zero bending torque, absence of a fatigue failure mode, low insertion loss and a good impedance match at all angles of operation and over large bandwidths.

Abstract: A waveguide expansion joint for connecting two circular waveguides operating in the TE.sub.01 mode while allowing for waveguide expansion and contraction due to temperature variations. The expansion joint includes first and second rings on the outside surface at one end thereof. When the expansion joint is inserted into a waveguide the rings are proximate to the inside diameter of the waveguide for absorbing undesired propagating modes, for pressurization of the expansion joint, and for coaxially aligning the waveguide and the expansion joint.

Abstract: A pivoting joint connects two rectangular waveguides, connecting transmission-reception equipment on board a satellite to an antenna, which is only opened out when the satellite has been placed in orbit. These waveguides comprise a fixed section and a moving section, pivoting about the longitudinal axis common to the two sections. They issue or open out in facing manner on two parallel planar faces separated by a non-zero distance, but which is very small compared with the wavelength. One of these faces has a quarter-wave trap ensuring the radio seal of the joint. An abutment defines the position in which the two guides are in an extension of one another. When the satellite reaches orbit, antenna is opened out and the joint pivots to this position.

Abstract: An antenna having a rotatable phase center is disclosed. The antenna includes a horn antenna having a phase center and at least one rod-like impedance element located adjacent a wall of the horn antenna near the phase center. The length of the impedance element is selected such that it shifts the phase center from its normal, undisturbed location without substantially affecting the amplitude pattern of the antenna. Means is provided for mechanically rotating the rod-like impedance element around the phase center so as to thereby cause the phase center to also rotate.

Abstract: A rotary waveguide coupling including coupling members which are coaxially rotatable with respect to one another and comprise waveguide sections produced by dividing an annular waveguide in a longitudinal sectional plane. Inputs and outputs of the waveguides to be rotated with respect to one another disposed in the side walls of the waveguide sections.

Abstract: The wide ends of two similar horn structures are juxtaposed and joined by a rotary bearing extending thereabout which permits relative rotational motion between the two horn structures. A field shaping lens may be disposed at the relatively rotatable horn juncture to help insure substantially planar wavefront shapes across the relatively rotatable joint. An annular aperture may also be provided between the relatively rotatable horns and electrically loaded so as to present an approximate short circuit electrical impedance at the intended frequency of operation.

Abstract: Two coupled cavity type, slow-wave circuits are separated, with a drift space section between them. An electron beam and an electromagnetic wave, which do not interact with each other, over a certain length, are in the drift space. A waveguide type non-reflective termination structure has a waveguide axis directed in the same direction as the electron beam and is coupled to the cavity, slow-wave circuits with respect to a high frequency wave disposed in the drift space section. With such a construction, a traveling wave tube is formed with a PPM focusing and with a non-reflective termination structure includes a waveguide member having a through-hole for passing an electron beam and two waveguides formed on the opposite sides of the through-hole. A lossy ceramic member is disposed within one of the two waveguides for a forwardly traveling wave and another lossy ceramic member is disposed in the other waveguide for a backwardly traveling wave.

Abstract: a dielectric waveguide is used as a connecting medium in a rotary joint tsmitting waveguide energy in the 3 mm region. The dielectric waveguide is fastened within a ball bearing race to provide relative motion between the gimballed and stationary waveguide structure. Launch horns are used to enhance transmission through said dielectric waveguide.

Abstract: This invention concerns a slow-wave circuit which is electrically equivalent to the well-known folded-waveguide or coupled-cavity circuit with staggered coupling slots. The central portion of the circuit is a metallic ladder. The ladder rungs are wide and flat to form the equivalent of flat cavities. The rungs have axially aligned holes thru their centers for beam passage. A pair of coupling ladders are joined to opposite sides of the central ladder. They have apertures or recesses spaced at twice the pitch of the central ladder; the recesses are aligned to provide a coupling duct between each pair of adjacent cavities, and cavity-closing walls at the ends of the pair. The coupling recesses in the two coupling ladders are staggered by the cavity pitch so that the coupling ducts are on alternating sides of the cavities.

Abstract: A TE.sub.01 circular mode waveguide expansion joint, tapered transition dce in which the expansion joint includes a linear tapered section, the greatest diameter of which does not exceed the cutoff diameter for the TE.sub.02 spurious mode. A second taper of the cosine or other suitable type minimizes TE.sub.02 mode generation as the guide diameter increases past the TE.sub.02 cutoff value. The expansion, transition device simultaneously performs the functions of expansion section and waveguide diameter transition for the TE.sub.01 circular mode while minimizing spurious mode generation.

Abstract: This specification discloses a polarization network for selectively converting between linear and circular polarization. The network includes a twistable waveguide having a generally rectangular cross section. Coupled to the twistable rectangular waveguide is a transducer waveguide which acts as an interface between the rectangular waveguide and circular waveguide. A polarizer having a generally circular cross section is coupled to the transducer waveguide and can convert transmitted electromagnetic waves between linear and circular polarization. A coupling means permits relative rotation between the transducer waveguide and the polarizer and selective securing at any of three rotational positions. A first position permits a linearly polarized signal to pass through the polarizer remaining linearly polarized. A second position converts between a linearly polarized signal and a right hand circularly polarized signal.

Abstract: A junction for connecting together two waveguides whose major transverse axes are inclined to one another, composed of elements connecting the frontal faces of the waveguides in such a manner that their major axes are adjustably inclined to one another, flanges covering the nonoverlapping frontal faces of the two waveguides, and reactance components disposed at the point of discontinuity produced by the angular offset between the waveguides for compensating for such discontinuity over a broad frequency band.

Abstract: An I type (straight) double ridge waveguide rotary joint is provided by connecting input and output sections of double ridge waveguide, oriented along a common axis, to opposite ends of a coaxial line rotary joint that is on the same axis. The input and output sections each connect to the coaxial line rotary joint by a transformer that connects one ridge to the center conductor of the adjacent coaxial line and the other ridge to the outer conductor of the coaxial line, the connections being made in several transitions to avoid an abrupt change of impedance in progressing along the axis through the transformer.

Abstract: A transmission path between a source of microwaves, such as a radar transceiver, and a load rectilinearly movable with reference thereto, such as an aerial mounted on a retractable mast of a submarine periscope, comprises two relatively movable parallel waveguides respectively connected to a pair of coaxial ancillary guide portions with mating extremities which are separated from each other in one relative position and are interfitted in another relative position of the source and the load. The male guide portion is externally grooved to form microwave chokes whose effect is enhanced by a peripheral layer of energy-absorbent coating disposed beyond these chokes as seen from the female guide portion. The main waveguides may be coaxial with the interfitting guide portions or may extend parallel thereto and be connected to them by respective elbows.

Abstract: The expansion joint includes a first component and a second component which have the same inside dimensions as the wave guide and are free to move longitudinally with respect to each other, the first component having exclusively a wave guide structure, the second component including a trap positioned at least partially between said components and outside the first component, the electric length of said trap being equal to half the wavelength of the central frequency transmitted by the wave guide, said components being separated longitudinally at the trap by a distance which varies when the length of the wave guide varies. The trap can be folded to reduce its bulk.Application to long wave guides.

Abstract: An expansion joint for connecting sections of waveguide includes a plurality of spacer discs mounted on a plurality of guide rods. The guide rods are rigidly affixed to a termination member. Washer type springs are employed between the individual spacer discs on the guide rods for controlling increases and decreases in the space between the discs and, hence, compensating for contraction and expansion, respectively, of the waveguide sections while maintaining a uniform electrical path through the joint. Additional spacer discs having various thicknesses are also employed to allow for a predetermined maximum initial length adjustment within a prescribed tolerance.