Abstract: Cavity filter with comb-line structure having a steep-flanked flanked pass-band. To obtain this steep flank, rejectors are positioned in the vicinity of the access bars of the filter, orthogonally to the teeth of the comb-line structure. The best results are obtained for the flanks corresponding to the high frequencies of the pass-band, namely with rejectors tuned to frequencies higher than the center frequency of the pass-band.

Abstract: An inductive output tube, e.g., a KLYSTRODE, or a klystron, has a substantially hollow electron beam traversing a resonant cavity excited to the TM.sub.0x0 mode, where x is greater than 1.

Abstract: A cylindrical microwave cavity 12 has a pinched center 28, 30. Two apertures 28, 30, one in the center. of each face of the cylinder 10, provide access for a gas/powder mixture 124 having a dielectric coefficient depending on its density or some other measurement of interest. The faces 20, 22 of the cylinder 10 are much farther apart at the unpinched periphery, which comprises most of the volume of the cavity. The wider spacing allows an antenna 34 to be placed in the cavity 12, and provides a high Q-factor to maximize the sensitivity of the cavity 12. At the same time, certain resonance modes are greatly affected by a change in the dielectric coefficient of the gas/powder mixture 124 in the pinched portion 28, 30. The density of the powder or any other convenient variable may thus be servoed to any desired value. The powder 124 may be blown through the cavity 10, encased in tube 120 affixed to the cavity 12.

Abstract: A radiofrequency resonator for nuclear magnetic resonance imaging and spectroscopy of the human head in which the geometry of the resonator comprises a single end ring connected to a plurality of legs which extend along a cylinder and which are joined in pairs on a hemispherical dome.

Abstract: The invention relates to a resonator shell construction, comprising at least two metallic shell modules (41-44) connected to each other to form a modular shell construction, each module enclosing at least one resonator cavity (42-52). The modules comprise wall portions (41a-41c, 42a-42c, 43a-43c, 44a-44c) projecting from the modules, said wall portions being connected to one or more modules, whereby one or more new resonator cavities (61-68) are formed between the modules.

Abstract: A bandpass microwave filter (32) is constructed by use of a right cylindrical cavity resonator (10) wherein end regions (22, 24) of the resonator are tapered. The tapering is accomplished by replacing end portions of a right cylindrical sidewall with frusto-conic sections (22, 24) of side wall. Each frusto-conic section joins a central cylindrical section (26) of the sidewall with a planar end wall (14, 16). Each of the end walls is provided with a coupling slot (28, 30) having dimensions substantially smaller than a half wavelength of the center resonant frequency of the resonator so as to be a nonresonant slot. The slots in the end walls may be coupled to rectangular waveguides (34, 36) which form input and output ports by which electromagnetic signals are applied to and extracted from the resonator.

Abstract: A tag structure suitable for attachment to an object and for being remotely sensed, includes at least one soft magnetic element mounted for being excited in an inhomogeneous magnetic field. The soft magnetic element includes first and second ends and is clamped at at least one of the first and second ends. Each soft magnetic element responds to the excitation to produce a unique, time-varying magnetic field corresponding to its resonant frequency, when excited. A system incorporating the tag includes an excitation device and a detector for detecting the mechanical vibrations of the soft magnetic element.

Abstract: A distributed impedance circuit MR coil design comprised of a transmission line tunable cavity resonator which is well suited for but not limited to use at high frequencies and for large volumes such as in high field (e.g. 4.1 tesla) clinical MR applications. The distributed circuit transmission line resonator is designed for high frequency, large conductive volume applications where conventional lumped element coil designs fail. A resonant coaxial cavity is variably tuned to the Larmor frequency of interest by tunable transmission line elements. The resonator is effective for large head and body sized volumes, high efficiencies, and broad tuning ranges to frequencies of 500 MHz. The B.sub.1 homogeneity of the resonator is a function of the electromagnetic properties of the load itself. Maxwell's equations for the fully time-dependent B.sub.1 field predicts "coil" homogeneity with finite-element models of anatomic structure.

Abstract: A radiofrequency resonator for nuclear magnetic resonance imaging and spectroscopy of the human head in which the geometry of the resonator comprises a single end ring connected to a plurality of legs which extend along a cylinder and which are joined in pairs on a hemispherical dome.

Abstract: A method of generating high-power microwaves from a compact source is disclosed by which a transmission line cavity resonator is charged to a high voltage and an electrical switch in the resonator is closed very quickly to produce subnanosecond current risetime and a resultant high-power microwave pulse. Structure to accomplish the method is also disclosed.

Abstract: A microwave cavity device having close frequency resonant modes wherein the major portion of the electromagnetic field energy of each mode is localized in a different region of the cavity is presented. The device can comprise one or several inputs, one or several outputs and tuning elements. These, together with the localization of the modes make the device suitable for different applications such as filters, multiplexors, switches. A class of cavities presenting localized modes are disclosed. These cavities are used in embodiments which have the advantage of being relatively simple, compact, with low insertion loss, high quality factor and simple tuning. Such cavities can be coupled in larger structures.

Abstract: A microwave cavity closure structure encloses an upper splitter cavity bounded at its top and bottom by, respectively, a rigid metal plate and a flexible sheet metal dish and (b) a lower combiner cavity bounded at its top and bottom by another such dish and another lower such plate. Each such cavity has a central region occupied by a raised circular boss, and the lower plate bounding the bottom cavity mounts, outward of the central boss, two concentric annular sheet metal rings each having a flat top and peripheral flanges extending from the margins of that top down into annular grooves in the lower plate. One or more rings of dielectric posts are disposed in each cavity radially between the central boss therein and the cavity periphery to vertically space at the ring's location the plate and dish of the cavity by a distance determined by the posts, while concurrently permitting the dish to be flexed in the cavity's central region for cavity tuning purposes.

Abstract: A microwave cavity closure structure encloses an upper splitter cavity bounded at its top and bottom by, respectively, a rigid metal plate and a flexible sheet metal dish and (b) a lower combiner cavity bounded at its top and bottom by another such dish and another lower such plate. Each such cavity has a central region occupied by a raised circular boss, and the lower plate bounding the bottom cavity mounts, outward of the central boss, two concentric annular sheet metal rings each having a flat top and peripheral flanges extending from the margins of that top down into annular grooves in the lower plate. One or more rings of dielectric posts are disposed in each cavity radially between the central boss therein and the cavity periphery to vertically space at the ring's location the plate and dish of the cavity by a distance determined by the posts, while concurrently permitting the dish to be flexed in the cavity's central region for cavity tuning purposes.

Abstract: A resonator mounting apparatus for use in a circuit (10) captively secures and positions a resonator (40) within a resonator cavity (15). The resonator mounting apparatus uses a pedestal (60) attached to the base (12) of the resonator cavity and a web support (50) attached to a cover (30) for the resonator cavity. Both the pedestal and the web support slip fit into corresponding holes in either the base or the cover. The distance between the pedestal and the web support is chosen to secure the resonator therebetween. The pedestal includes a resonator engagement means such as a peg (70) which extends into the resonator cavity to engage a complementary hole (42) in the resonator. Alternately, a circumferential lip (64) extends from the pedestal to engage the resonator. The web support is designed to flex when engaging the resonator. The resonator mounting apparatus is preferably assembled by an automated assembler without the use of glue or epoxy.

Abstract: A resonator is provided for electron spin resonance spectroscopy. The resonator comprises walls defining a cavity. In the cavity, a predetermined oscillation mode of a preselectable frequency, in particular in the Q band, is capable of propagating. The walls are provided with an opening for irradiating a radiation, in particular light rays. The cavity has a cylindrical shape. An oscillation mode of the type TE.sub.01n is excited, with n being greater than one. The opening is configured as an annular slot extending substantially all around the cylindrical jacket, which defines the cavity, in a radial plane at a distance of m L/4 from a radial end wall delimiting the cavity, and m is an odd number and greater than one (FIG. 2).

Abstract: A load for a stripline integrated into a three-plate structure is formed by a resonant cavity filled with absorbent material. The resonant cavity is defined by metallized holes extending through the three plates. The holes are spaced no more than 1/4 wavelength apart and can extend along the length of the stripline to form an opening of the resonant cavity. The structure of the load allows its size to have the same height and width of the stripline.

Abstract: Numerous high frequency signals are combined in a system of cavity band-pass filters. Each filter has a bottle shape so that adjacent filters may be fitted together into a compact system. Bridges connect the adjacent filters.

Abstract: A rectangular microwave resonant cavity applicator comprising two spaced-apart, cavity-containing sections is disclosed for heating a product web. Each section has a planar peripheral lip which faces the other and the sections are spaced apart by a distance "d". The lips have arrays of ferrite segments mounted on their surfaces which serve to limit radiation of microwave energy from the open space between the sections, through which the product web passes.

Abstract: Modular resonant cavities particularly for use in applications associated with high frequency electromagnetic energy each comprise a shell defining an aperture formed therethrough, and either end plates and/or divider closure plates, each having stepped-down regions for interfitting at perimeter ends of adjacent shells so as to form a resonant cavity. The modular resonant cavities include support rods passing through the corner regions of each closure plate. Fastening means at each end of the rods mechanically secure the modular resonant cavities together.

Abstract: A combiner arrangement in a radio base station including a number of waveguide cavity resonators operating as channel filters in known manner. According to the invention, each resonator is divided into two substantially equal cavity resonsator parts. One base station transmitter is connected to one of the resonator parts and another transmitter is connected to the other resonator part. The decoupling of a resonator consists of two clamp-like elements situated in the center of the resonator. The coaxial connection to the antenna consists of coaxial pieces between the resonators and all the resonators are connected in series to the antenna.

Abstract: A filter having a dielectric resonator, the filter comprising at least one cylindrical cavity (10) inside which there is a dielectric resonator (11) whose axis of symmetry (.DELTA.) is colinear with the axis of symmetry of the cavity (10), the filter being characterized in that the resonator is held by a system of dished washers (15, 16). Applicable to microwave frequencies.

Abstract: An open resonator comprises two concave spherical reflectors or one spherical and one plane reflectors positioned so as to form a resonant structure and each being provided at an electromagnetic coupling region thereof with a large number of conductor stripes disposed in parallel at a spacing sufficiently small in comparison with the wavelength of an incident electromagnetic wave. The diameter of the circular coupling region can be made very large in comparison with the wavelength. An ultra-high Q value can be obtained with the open resonator with very high excitation efficiency to a resonator mode. The Q value of the open resonator can be varied with the angle between the directions of the conductor stripes of the two reflecting mirrors.

Abstract: The cavity resonator is composed of a closed metallic body transversely subdivided into two parts, housing a small dielectric cylinder, which is held in coaxial position inside the cavity by two small quartz plates provided with a centering indentation. Holes are provided in the lateral surface for tuning screws and an access connector and coupling irises can be cut in the bases.

Abstract: A microwave cavity filter using resonators of superconducting coatings, one-half wavelength long on quartz tubes mounted within the cavity that carry refrigerant to cool the superconductor substantially reduces ohmic losses and permits shrinking the size of conventional cavity filters.

Abstract: A band elimination filter which includes at least one or more TM-mode dielectric resonators each including a ceramic casing with an electrically conductive film formed over its inner surface or outer surface, and a dielectric column disposed in a cavity in the ceramic casing, and an electrode provided on the ceramic casing, out of contact with the electrically conductive film, with transmission lines being connected to the electrode.

Abstract: A microwave resonant cavity for a spectroscopic light source includes a housing having therein a chamber formed by side walls and a cylindrical outer wall. The side walls having aligned openings therethrough which are on the longitudinal axis of the outer wall. A refractory tube which is adapted to contain a gaseous plasma extends through the aligned openings and across the chamber in the housing. The portion of the side walls of the chamber adjacent the openings are closer together than the remaining portions of the side walls so that the chamber has a first portion around the refractory tube which is narrower than a second portion of the chamber around the first portion. A coupling loop is electrically coupled to a side wall of the chamber within the second portion of the chamber and is connector to a coaxial connector which extends through the outer wall of the housing to deliver microwave power to the chamber.

Abstract: A band pass-band reject filter in which the filter housing which comprises the resonant cavity is contained within an annular wall that is supported at each end by an end plate. The filter is connected to an instrument rack or the like by the distal ends of bolts which extend between the end plates and which lie closely along side the annular wall. The end plates are soldered to the annular housing. The bolt heads are soldered to the end plate and their shafts are soldered to the side wall.

Abstract: A filter having a dielectric resonator, the filter comprising at least one cylindrical cavity (10) containing a cylindrical dielectric resonator (11) whose axis of symmetry (.DELTA.) is colinear with the axis of said cavity (10), and the resonator being held in a longitudinally asymmetrical position inside said cavity (10) by a mandrel system which clamps around the cylindrical portion thereof and which includes at least one spoke for fixing it to said cavity while leaving play relative to said cavity.

Abstract: The structures for confining or guiding high frequency electromagnetic radiation have surfaces facing the radiation constructed of high temperature superconducting materials, that is, materials having critical temperatures greater than approximately 35.degree.K. The use of high temperature superconductors removes the constraint of the relatively low energy gaps of conventional, low temperature superconductors which precluded their use at high frequencies. The high temperature superconductors also provide larger thermal margins and more effective cooling. Devices which will benefit from the structures of the invention include microwave cavities, millimeter-wave/far infrared cavities, gyrotron cavities, mode converters, accelerators and free electron lasers, and waveguides.

Abstract: A waveguide band-pass filter has at least two resonators each consisting of a high-impedance section and a low-impedance section. The resonators are cascade-connected at intervals of .lambda.g/4 in a waveguide.

Abstract: A uniform surface current density is approximated in an RF transmitting/receiving NMR coil by employing a plurality of discrete conductors having a resonantly distributed current. Inductive and capacitive lines provide a sinusoidal current distribution with various resonant modes providing different magnetic field orientations. The distributed current reduces losses. In a second order resonant mode, decoupling of the surface coil from a transmit coil is achieved without a blocking network.

Abstract: A microwave resonating cavity including a hollow cylindrical body shaped in the form of a parallelepiped and consisting of a dielectric material coated by a metallic layer, said dielectric material having a high dielectric constant having a value greater than 30, and wherein said hollow body includes an upper base, a lower base, an external surface and an internal surface, and further includes a non-metallized area defining a metallized coupling line onto the external surface of the said hollow cylinder and wherein said hollow cylinder has an inner diameter ranging between 3 and 5 mm, an outer diameter ranging between 6 and 15 mm and a height ranging between 5 and 10 mm, and further including a metallic cap welded to the upper base of said hollow body, and further including an adjusting screw for fine adjustment of the resonating frequency.

Abstract: Improved apparatus and method are provided for the coherent amplification and injection of radio-frequency (rf) energy into a load cavity using a plurality of amplifier tubes. A plurality of strip line cavities (30, 32, 34, 36, 40, 42, 44) are laterally joined to define a continuous closed cavity (48), with an amplifier tube (50, 52, 54, 56, 58, 60, 62, 64) mounted within each resonant strip cavity. Rf energy is injected into the continuous cavity (48) from a single input (70) for coherent coupling to all of the amplifier tubes for amplification and injection into the load cavity (76).

Abstract: Bulk production of carbon fibers by a spinning process incorporating the exposure of the fibers to a level of electron plasma to achieve the curing to carbonization stage as desired. Fibers are also broken into shorter lengths for particular uses.

Abstract: An oscillator with a dielectric resonator capable of providing a designated output and being suited for mass production comprising an insulating substrate, a strip structure, a dielectric resonator located adjacent to the strip structure, the last two being mounted on the substrate, and an oscillatory transistor connected to one end of the strip structure. The strip structure consists of two spaced strip sections interconnected by an electrically-conductive bridge-shaped connector section having a conductor part, which is located further away from the insulating substrate and closer to the dielectric resonator than the two strip sections.

Abstract: An antenna device for exciting a magnetic high-frequency field and/or for receiving corresponding high-frequency signals in a nuclear spin tomography apparatus contains a tubular antenna part which is designed to largely pass low frequencies, for magnetic gradient fields, consists of electrically highly conductive nonmagnetic material and has means for connecting to an external energy feeding or receiving device. In order to permit a simple design for this antenna device, only the tubular antenna part is provided as a circular waveguide for exciting or receiving the high frequency field. The circular waveguide is provided at least in the region of the cross-sectional plane extending through the center of its axial dimension with a system of coupling elements for coupling in or out the corresponding high-frequency power. In addition, further coupling systems may be provided in at least two cross-sectional planes symmetrical to the central cross-sectional plane.

Abstract: A generator of short electromagnetic waves is provided with a novel form of resonant cavity having improved mode selectivity. The reflecting walls of the cavity correspond to a surface of revolution and the meridian planes include four discrete mirror zones which face each other and are positioned so that the centers of the mirror zones form the vertex of a polygon and the normals to said mirror zones at the centers are bisectors of the angles formed at the vertices of the polygon.

Abstract: A bandpass filter has a plurality of cascade cavities that operate in a dual-mode and are mounted in a planar relationship to one another. Each cavity contains a dielectric resonator and resonates at its resonant frequency in two HE.sub.11.delta. modes. An iris is located between adjacent cavities and contains an aperture that can independently control inter-cavity coupling. The dielectric resonator is cylindrical in shape and an adjustable metallic plunger is located in a wall of each cavity so that the cavity can be tuned over a relatively broad range. The filter has good mechanical and thermal stability as well as being extremely flexible in the arrangement of cavities.

Abstract: A dielectric resonance apparatus for resonating in a TM mode such as TM 110 or the like. The apparatus includes a case having therein at least two TM-mode dielectric resonators, these resonators being oriented in the case so that their magnetic fields intersect each other. The apparatus also comprises means for coupling the magnetic fields. The TM-mode dielectric resonators may be integrally or separately formed. Each adjacent pair of resonators may be magnetically interconnected by an irregularly shaped portion of the case, such as a depressed portion or a projecting portion, for influencing the respective magnetic fields of each resonator by a selected degree, such that different respective degrees of influence are obtained with respect to the even and odd modes to be produced by the two resonators.

Abstract: In a Y circulator, the ferrite body is so dimensioned that at the operating frequency, not the dominant mode, but two higher order modes are excited having their frequencies close to each other.

Abstract: A cavity resonator serves to generate magnetic dipole transitions in a sample, for instance for carrying out electron spin resonance measurements. The natural frequency of the cavity resonator (10) is influenced by a reduction in length of the E flux lines. To this end, conductive areas (20) are arranged at the points where the E flux lines are encountered. This results in an increase of the space factor, related to an unchanged specimen volume, and thus in an improvement of the measuring sensitivity.

Abstract: A dielectric resonator device which includes dielectric resonators constituted by a rectangular cavity shield casing and a composite dielectric structure formed by three dielectric members intersecting at right angles with each other to be combined into one unit and disposed in the rectangular cavity shield casing to provide three resonances by TM.sub.110 modes or modified modes thereof which are utilized by the dielectric resonators, and an external coupling device for coupling the dielectric resonators with external circuits.

Abstract: The invention provides a self-focusing cavity for accelerating charged particles, intended to form the first or only cavity of a linear accelerating structure; this structure accelerating a charged particle beam along an axis merging with a longitudinal axis of this structure. The cavity of the invention comprises an input wall sloping with respect to said longitudinal axis so as to form a surface of revolution providing a charged particle focusing effect.

Abstract: A box-shaped metal microwave oscillator is provided having two pairs of substantially parallel, confronting inner surfaces, the second pair perpendicular to the first pair to define an oscillator cavity. The forward end of the cavity is walled off with a slotted wall to permit only a portion of the oscillator energy to be emitted. The spacing of certain of the walls and the location of the oscillator components to the wall is described.

Abstract: The process consists of preshaping the elements of the cavity prior to their assembly, covering the preshaped elements with at least one good electricity-conducting metal coating, positioning the different elements to form the cavity and then fixing all the elements to one another by melting and then cooling the deposited metal covering said cavity elements.

Abstract: A cavity resonator coupling-type power distributor/power combiner includes a first cavity resonator operatively resonating with a cylindrical T.sub.O,n,O mode, and a plurality of second cavity resonators arranged on the periphery of the first cavity resonator and extending radially and symmetrically with respect to the first cavity resonator. The second cavity resonators each have the same shape and size so that magnetic-field coupling is established between the first cavity resonator and each of the second cavity resonators, for distributing or combining microwave power in a microwave amplifier.

Abstract: A microwave dielectric resonator, e.g. for use in a microwave filter or oscillator, is provided with a tough low loss mount. The mount comprises a polymeric support layer 4, which is provided with an aperture 3 beyond which the resonator extends. About the first polymer layer 4 are a pair of polymeric retaining layers 2, 2'. These three polymer layers may be heat bonded together to secure the resonator. Interlayers 5 may be used between the three polymer layers 4, 2, 2' in order to effect a bond.

Abstract: The device comprises a cavity, a resonator placed within the cavity and a support plate for fixing the position of the resonator within the cavity. Recesses are formed in the cavity and the resonator at the point at which they are in contact with the support plate. The support plate is of thermocompressible material. The cavity comprises at least two parts and one of these parts is in contact with the support plate; in order to mount the resonator within the cavity this latter part is assembled with the support plate, the resonator, mechanical locking members and a piston so that the support plate is thus completely surrounded. The assembly is heated to the temperature chosen for thermocompression, whereupon the support plate is compressed by means of the piston. The thermocompressible material then fills the recesses and ensures rigid positioning of the resonator after cooling.

Abstract: A mm wavelength power combiner comprising an open resonator comprising a r of confronting concave reflectors which can be either spherical or parabolic. The resonator dimensions are many times the wavelength of the energy sources to be combined. A plurality of mm wave energy sources are applied to the resonator in such a way that the great majority of the energy bounces back and forth between the reflectors near the axis thereof in the fundamental or Gaussian mode. The design minimizes multimoding and diffraction losses.

Abstract: A distributed inductive reactance is coupled to a terminating impedance at the interface of a combiner probe with a resonant cavity. The distributed reactance is implemented by a metal insert having a cavity interface and having a coupling portion, which is coaxial with a cylindrical dielectric and with a cylindrical cavity in an end of the terminating impedance.