Abstract: A terahertz full-duplex co-local oscillator solid-state front-end transmitting circuit is disclosed, which belongs to the technical field of terahertz communication. The overall structure of the solid-state front-end transmitting circuit adopts a new system, wherein the circuit comprises two branches that are parallel and driven by a local oscillator source. A branched waveguide directional coupler is configured to output two driving signals provided by the same local oscillator source respectively to two branch circuits with required powers. Two transmission signals generated from the two branches are combined into one signal for transmission through an orthogonal mode coupled duplexer, so as to fulfill the construction of a full-duplex co-local oscillator solid-state front-end transmission circuit.

Abstract: A millimeter-wave reflective structure configured to reflect incident millimeter waves includes: a transparent substrate defining unit cells in the form of a matrix, the transparent substrate having an upper surface; and conductive patterns arranged in the unit cells on the transparent substrate, each of the conductive patterns having a hollow rectangular shape.

Abstract: This disclosure provides a reactor system that includes a microwave source configured to generate a microwave energy, one or more energy sources configured to generate a thermal energy and a field-enhancing waveguide (FEWG) coupled to the microwave source. The FEWG includes a field-enhancing zone having a cross-sectional area that decreases along a length of the FEWG. The field-enhancing zone includes a supply gas inlet configured to receive a supply gas, a reaction zone configured to generate a plasma in response to excitation of the supply gas by the microwave energy, a process inlet configured to inject a raw material into the reaction zone, and an afterglow region configured to combine the plasma and the raw material in response to the thermal energy. An outlet outputs a plurality of carbon-inclusive particles resulting from the combination of the plasma and the raw material. Electrodes can be positioned proximate to the reaction zone.

Abstract: A test system includes a radio frequency (RF) shielded chamber and an antenna array in the RF shielded chamber. The antenna array includes groups of antenna elements and power combiners. Each group of antenna elements is matched to a matching group of antenna elements by virtue of being coupled to a respective power combiner for both the group and the matching group. The antenna array is configured, by virtue of spacing apart the antenna elements by at least half of a wavelength of a test signal for testing a wireless device in the RF chamber, so that power delivered to output ports of the antenna array is substantially uniform regardless of where the wireless device is placed within the RF chamber.

Abstract: The disclosed exemplary apparatuses, systems and methods provide at least two realizations of synchronized antenna probe arrays. These antenna probe arrays may be used to generate and receive RF signals in a compact anechoic chamber for over the air antenna testing, or other applications such as far-field antenna test chambers. A compact anechoic chamber for over-the-air antenna testing may include at least: a chamber housing; an interchangeable irradiating test panel, integral to the chamber; a plurality of absorbing material at least partially lining an interior of the chamber and capable of directing the irradiating; at least one moveable cart suitable for moving and removing the antenna from the chamber; at least one panel interface for interconnecting the antenna and equipment for the testing, wherein a response of the antenna to the irradiating is communicated through the panel interface to the testing equipment; and at least one switch matrix for multiplexed switching of ones of signals of the testing.

Abstract: A radar level gauge having a wave guiding structure arranged to guide a measurement signal towards the surface and to return the reflected signal, and an electromagnetic wave transducer arranged to emit the measurement signal into the wave guiding structure as electromagnetic waves. The electromagnetic wave transducer has a plurality of radiating elements arranged in N?1 concentric feeder rings, where a radius of each feeder ring coincides with a radial zero of an electrical field of the H0N-mode, and feeding circuitry connected to feed the measurement signals from the transceiver circuitry to the radiating elements, thereby causing the electromagnetic wave transducer to excite electromagnetic waves in the H01-mode. With this choice of feeder ring radii, the H0N mode will not be excited.

Abstract: A filter is provided with a multilayer board incorporating a resonator formed by two ground plates opposed to each other and conductive side walls connected to the ground plates; two signal vias provided through the resonator; and two terminals connected to the signal vias to receive a pair of signals. The resonator has a first face of symmetry vertical to the ground plates. The signal vias are disposed symmetrically with respect to the first face of symmetry on a distance from the first face of symmetry.

Abstract: This invention relates to radiofrequency (rf) cavities and couplers that comprise metallic or dielectric rods to provide specified concentration of field patterns for the operating modes in the interaction region, for applications in particle accelerators, pulsed rf power sources, amplifiers, mode converters and power couplers.

Abstract: A microwave applicator for heating loads being a waveguide transition between the rectangular TE10 and TE20 modes comprising a TE10 mode section and a TE20 mode section. The location of the load being inside said TE20 mode section and with its major axis perpendicularly to the major propagation direction of the TE20 mode, close to a shorting wall of said TE20 mode section and also close to the centreline of said propagation direction.

Abstract: A device for manipulating microwave radiation includes a substrate that defines the shape of a surface for reflecting microwave radiation. The device also includes a metal fitting. The fitting conforms to the defined shape, and provides the surface that reflects microwave radiation.

Abstract: A test system having a shielded enclosure and common air interface for testing the transmit and receive functionality of wireless communication devices such as mobile phones. A test system according to the present invention provides improved fault coverage by permitting robust testing of the entire signal path of a wireless device, including the antenna structure. In one embodiment of the invention, an RF-shielded enclosure having a test chamber is provided. The structure of the shielded enclosure blocks ambient RF energy from entering the test chamber and interfering with testing operations. The shielded enclosure may be lined with an RF absorbing material to improve test repeatability. A novel test antenna structure is disposed in the test chamber for wirelessly communicating test signals to a device under test.

Abstract: A microwave filter cavity that exhibits spurious mode suppression. The microwave filter comprises a metal mode suppression tuning stub located in a replaceable iris plate that is used to suppress unwanted transverse magnetic (TM) modes of the filter cavity, The mode suppression stub is disposed normal to an end wall of the cavity. The mode suppression stub perturbs the E-field of transverse magnetic modes, while having negligible effect on desired transverse electric (TE) modes. The addition of the tuning stub has no effect on filter performance determined by transverse electric modes.

Abstract: A multimode dielectric resonator apparatus is configured such that a TM mode and a TE mode are transformed into multiplex modes, coupling between individual resonant modes can be easily made, and a large number of sequentially coupled stages can be obtained with a single dielectric core. In the multimode dielectric resonator apparatus, a dielectric core is configured of a plate-like TM-mode dielectric core portion and a TE-mode dielectric core portion protruding therefrom in the vertical direction, for example in a spherical shape. Five modes, namely a TMx mode, a TMy mode, a TEx mode, a TEy mode, and a TEz mode are used as multiplex modes. In addition, a filter and a duplexer use the multimode dielectric resonator apparatus, and a communication apparatus uses one or both of the filter and the duplexer.

Abstract: An apparatus for dampening standing wave pattern generation in a closed cavity of a microwave oven, includes a fluid table having an enclosure made of a microwave energy transparent material, such as plastic, and a structure, such as top flat platform held in place by the enclosure, for defining a processing surface for placement thereupon of samples to be processed, and a quantity of dielectric fluid contained by the enclosure so as to provide a large flat surface of the dielectric fluid beneath the flat platform and thus below the processing surface. The apparatus also includes mechanisms for recirculating the dielectric fluid to and from the enclosure and for cooling the dielectric fluid to maintain the dielectric fluid within a given narrow range of temperatures.

Abstract: A microwave applicator of microwave reflective material having a closed first end, four side walls and, in a first embodiment, an open second end spaced apart from and facing a ground plate, the ground plate extending in a pair of transverse directions and having a longitudinal direction perpendicular thereto, and in a second embodiment, a closed second end, the applicator forming a cavity containing a desired hybrid mode having a low wave impedance in the longitudinal direction and an absence of an E field component in one of the transverse directions.

Abstract: A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer.

Abstract: A microwave cavity including a pair of opposing clamshell halves, such halves comprised of a metal selected from the group consisting of silver, copper, or a silver-based alloy, wherein the cavity is further characterized as exhibiting a dominant TE.sub.011 mode is provided together with an embodiment wherein the interior concave surfaces of the clamshell halves are coated with a superconductive material. In the case of copper clamshell halves, the microwave cavity has a Q-value of about 1.2.times.10.sup.5 as measured at a temperature of 10K and a frequency of 10 GHz.

Abstract: A quasi-optical component for microwave radiation comprises a quasi-optical element (16a) which radiates incident microwave radiation along a major axis (19) and which has a characteristic transverse dimension (D) which is smaller than 50-times one wavelength. It is distinguished by the fact that a cooled absorption device (17) is provided which is arranged closely in front of the quasi-optical element (16a) in such a manner that at least one high-power secondary peak (20) of the diffraction due to the characteristic transverse dimension is destroyed.

Abstract: A dielectric resonator comprising a dielectric unit which is constructed by piling a plurality of plate-shaped dielectrics one on the other under pressure or adhering dielectrics to each other, so as to prevent an electric field in a resonance mode other than the dominant mode from passing through the faces thereof adhered to each other or brought in contact with each other under pressure, whereby the occurrence of a spurious response can be suppressed.

Abstract: An accelerating cavity having one or more iris structures mounted therein for strongly damping unwanted frequencies that are generated in the cavity by bunches of particles in a particle beam that is accelerated through the cavity during its operation. Each of the iris structures is characterized by containing a plurality of radial slots therein that extend from the central aperture through the iris member to the perimeter thereof. The outer end of each of the radial slots includes an enlarged portion that is effective to prevent undesired frequencies from being reflected back into the center aperture of the iris member. Waveguide means connect the outer ends of the radial slots to frequency damping means or to a dump or dumps.

Abstract: A gyrotron interaction resonator 29 operating in a TE.sub.n1 cavity mode has an array of longitudinal slots 32 in the conductive wall 30. The slots 32 are spaced to couple to the unwanted TE.sub.n1 modes and to other modes of differing n and not to the desired mode. Wave-absorptive material 34 spaced from the inner cavity wall 28 and coupled to slots 32 absorbs the unwanted modes.

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 microwave band pass filter for filtering electromagnetic signals has a set of cavities arranged serially, with a block of dielectric material filling each cavity to define regions of each cavity which are loaded with dielectric material and regions which are free of the dielectric material. Each cavity may be viewed as a resonator for a fundamental mode of progagation of an electromagnetic wave while each block can be viewed as a resonator for higher-order modes of propagation of electromagnetic power. The cavities are separated by walls having slots aligned with the free regions of the cavities for coupling power from the fundamental mode while minimizing interaction with power of the higher-order modes. The filter enables the construction of an enlarged passband while inhibiting the presence of the spurious higher-order modes in a stop band bordering the passband.

Abstract: A synchrotron-type accelerator of the invention has a torus-shaped beam duct and an acceleration section inserted in the beam duct. The acceleraton section has an accelerating cavity communicating with the interior of the beam duct. An RF electric field is applied to the interior of the accelerating cavity. A damping antenna such as a loop antenna is arranged in the accelerating cavity. The damping antenna is supported to be movable in a direction with proper angle to the axis of the accelerating cavity and is connected to a linear drive unit arranged outside the acceleration section. The linear drive unit moves the damping antenna in a direction with proper angle to the axis of the accelerating cavity, so that an insertion amount of the damping antenna with respect to the accelerating cavity is varied.

Abstract: A resonator in which the input and output transducers are positioned to couple strongly into a resonant mode of interest. Signal drains are included to drain energy out of spurious resonant modes. In a magnetostatic wave resonator, the signal drains are preferably grooves in the surface of the ferrimagnetic film forming the resonator cavity.

Abstract: A microwave oscillator (11) stabilized by a dielectric resonator (12) constituted by a housing (13) accommodating the dielectric resonator circuit and haing a fixing surface (14) and by a support (15) having an outer surface (16) on which the housing (13) is secured. The interface between the housing (13) and the support (15) has space-defining means (17,18,19) such that the housing (13) is subjected to flexural strain when fixed by its fixing surface (14) on the other surface (16) of the support (15).

Abstract: A device for guiding an electron beam from an electron gun to a microwave resonator in a microwave source operating according to the gyrotron principle, including a beam duct for guiding the electron beam, wherein the beam duct encloses the electron beam and has an electrically highly conductive surface area. For damping unwanted wave modes inside the beam duct, a plurality of damping openings are provided in the surface area of the beam duct. The characteristic aperture size (a) of the damping openings is larger than the wavelength of the modes to be damped. A particularly simple implementation employs wire mesh with an appropriate mesh size used as the material for the surface area of the beam duct.

Abstract: A microwave oscillator having very low phase noise characteristics has a reflection oscillator circuit coupled to a right-circular cylindrical resonant cavity designed to operate in the TE.sub.011 mode. The resonator length L and inner diameter D are restricted to a range of values such that (D/L).sup.2 is less than 2.5 but greater than 1.7. To suppress the TM.sub.111 resonant modes in the resonator, two techniques are employed. A single tuning post is disposed on either resonator end plate at a point where the TM.sub.111 electric field Z-component is a maximum. The post length is adjustably fixed to maximize the output microwave power at the cavity output port. Each end plate also has a continuous gap separating each plate from the housing to suppress electric field currents of the TM.sub.111 mode flowing on the inner surface of the resonator.

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 ferromagnetic resonator employing a disk of ferrimagnetic material is disclosed. The ferromagnetic resonator comprises a disk of ferrimagnetic material such as yttrium iron garnet (YIG) and a magnet applying D.C. magnetic field perpendicularly to a surface of the disk, and microstrip line applying RF magnetic field to the disk. The disk of ferrimagnetic material is processed to have a groove at a predetermined position on one surface of the disk, or to have a predetermined area in a central portion of the disk with a thickness smaller than that of peripheral portion of the disk, so that spurious response caused by magnetostatic mode other than the uniform mode is suppressed.

Abstract: A radio frequency resonant cavity having a fundamental resonant frequency and characterized by being free of spurious modes. A plurality of spaced electrically conductive bars are arranged in a generally cylindrical array within the cavity to define a chamber between the bars and an outer solid cylindrically shaped wall of the cavity. A first and second plurality of mode perturbing rods are mounted in two groups at determined random locations to extend radially and axially into the cavity thereby to perturb spurious modes and cause their fields to extend through passageways between the bars and into the chamber. At least one body of lossy material is disposed within the chamber to damp all spurious modes that do extend into the chamber thereby enabling the cavity to operate free of undesired spurious modes.

Abstract: For damping undesired high frequency electromagnetic oscillations on HF technology components, such as coaxial lines, waveguides and resonators, as well as for the use in resonant circuits of VHF amplifiers with high HF power electron tubes, an absorber is proposed, which can be stablely coupled in mode-selective manner, while having a negligible influence on undesired low frequency and/or other electromagnetic oscillations, while having a predetermined high-pass characteristic.Absorber elements are used, which comprise a pocket made from a material having a high electrical conductivity with an opening on one longitudinal side and surrounding a ferritic, dielectric or ohmic absorber rod.For amplifying the absorption effect and for the predetermined setting of the absorption direction, a plurality of these absorber elements can be arranged with a predetermined geometry with respect to the component generating, transporting and/or emitting the HF power.

Abstract: A method for designing low loss cylindrical TE.sub.011 mode resonators which permits selective placement of a transmission null at a frequency near the TE.sub.011 resonance frequency. The frequencies of the TE.sub.211 and TE.sub.311 modes, that are naturally excited in the resonator, are controlled by the angular displacement of the resonator input port and output port and by the relative amplitude of the TE.sub.011 mode compared to the TE.sub.211 and TE.sub.311 modes. Proper placement of the transmission nulls improves the selectivity of the TE.sub.011 resonator, and/or can be used to filter out unwanted noise at the frequency of the transmission null. A lumped constant analog circuit model is presented to assist in design of the resonator.

Abstract: A microwave oven comprising a heating cavity, a controllable frequency microwave power source, a detector for detecting the intensity of the electric field in the cavity and control means for setting the microwave power source at the frequency as determined by the intensity of the electric field. The frequency at which the loaded cavity is energized is selected by the control means to store high power in the cavity. The dimensions of the cavity are selected for generating only the TE.sub.m0p mode at the frequency of the microwave power source which is limited to 915.+-.13 MHz, where 0 is the mode index in the direction of the height of the cavity.

Abstract: In a gyrotron electron tube of the gyro-klystron or gyro-monotron type, having a cavity supporting an electromagnetic mode with circular electric field, spurious resonances can occur in modes having noncircular electric field. These spurious resonances are damped and their frequencies shifted by a circular groove in the cavity parallel to the electric field.

Abstract: The simulation of systems generated electromagnetic pulses in a space environment for satellite testing is accomplished by means of a spherical test chamber that is coupled with a pulsed x-ray source. Resonance damping is provided by a spherical resistive resonance suppression grid that is placed within the test chamber and spaced from its inner surface by a distance that effects optimum damping of electromagnetic wave energy at the fundamental chamber standing wave frequency. Electrons generated from surfaces within the chamber are suppressed by a spherical resistive electron backscatter suppression grid disposed between the resonance suppression grid and the chamber inner wall and by coating the inner chamber wall with electron emission suppression material.

Abstract: An efficient higher order mode resonant combiner in which a higher order mode accumulator cavity is adjusted to have the real part of its input characteristic impedance to be so minimized as to be less than the characteristic impedance Z.sub.o of the input circuit. When an active device is matched to this low, minimized value of cavity input impedance a mismatch results between the active device power source and the input to the combiner at undesired higher order modal frequencies. This resultant mismatch at undesired modal resonances obviates the need for mode suppression devices within the cavity which devices as taught in the prior art had detrimental effect of the efficiency of the combiner.

Abstract: A mode filter apparatus for preventing unwanted modes in a multi-moded structure utilizing a radial plurality of resonant slots on the bottom of the filter cavity. The top of the filter cavity includes a variable height center section to provide mode selectivity in cooperation with the resonant slots.

Abstract: The specification describes a dielectric image guide harmonic pumped mixer circuit wherein two dielectric image guide strips of different chosen cross-sectional configurations are mounted on a metallic substrate which forms the image plane for the mixer circuit. These image guide strips have impedance matching tapered ends which extend into a central mixer cavity region on the substrate. A pair of reverse poled mixer diodes are mounted in the central cavity region to receive respectively RF incoming signals from one dielectric image guide and local oscillator signals from the other dielectric image guide. Differential currents generated in the two diodes cause the second harmonic of the local oscillator signal frequency to mix with the incoming RF signal frequency. An intermediate frequency (IF) signal current produced thereby is conductively coupled from the mixer cavity into IF signal processing electronics.

Abstract: A microwave power combiner is shown to consist of a plurality of coaxial diode oscillators disposed on the periphery of a circularly cylindrical cavity operating in the TM.sub.020 mode, such cavity containing mode suppressor means to prevent any mode other than the TM.sub.020 from operating.

Abstract: A conductive body with a cylindrical cavity, designed to resonate at a certain operating frequency in the TE.sub.01 mode, has an input opening at one end and a conductive insert at the opposite end which alters the effective axial length for parasitic waves propagated in the TM.sub.11 mode. The insert may have the form of a smaller cylinder with a closed end beyond that of the main cavity, increasing the effective length, or of a set of radial vanes reducing the effective length. The insert, in either case, may be axially shiftable to tune the cavity to different resonant frequencies.

Abstract: A device for attenuating electromagnetic cavity interference waves, which occur in the vacuum system of a high-frequency electron tube, in particular a transmitting tube, comprising a wave-guide portion coupled to the cavity of the electron tube, which may or may not form a part of the vacuum system of the electron tube, and which wave-guide portion may have a length corresponding approximately to a quarter wave length of the interference waves, and is provided with a high-ohmic resistive coating, the high resistance of which is transformed by the wave-guide portion into a low resistance with respect to the cavity interference waves which are to be attenuated, in the cavity of the electron tube.

Abstract: A device for a resonant microwave cavity which includes a tuning plunger assembly to make the resonant frequency less temperature sensitive. The frequency response of a cavity filter, determined by its resonant frequency, primarily depends on the dimensions of the filter cavity. Since cavity dimensions will vary with changes in ambient temperature, some form of compensation is necessary to stabilize the frequency response. The tuning plunger assembly is comprised of a sandwich of materials having substantially different coefficients of expansion. One of the materials, a potting compound with a high coefficient of thermal expansion, acts as an operator to vary the configuration of the plunger assembly in order to maintain the resonant frequency of the cavity substantially fixed.