Showing papers on "Dielectric resonator antenna published in 1991"

Coplanar waveguide excitation of dielectric resonator antennas

Abstract: The circuit and radiation properties of a cylindrical dielectric resonator antenna excited by a coplanar waveguide feed are investigated. The coupling between the feed and the radiator was measured as a function of the position, dielectric constant, and height of the cylinder. The radiation patterns and resonant frequencies were also measured. These measured results are found to be in good agreement with theoretical calculations. >

Measurement of dielectric constant using a microstrip ring resonator

Abstract: An approach for measuring the permittivity of dielectric materials by means of a microstrip ring resonator is presented. The method is used in conjunction with the variational calculation of the line capacitance of a multilayer microstriplike transmission line to compute the effective permittivity and hence the resonant frequency of the ring. The results are compared with measurements made in X-band waveguide cavity-by-cavity perturbation techniques and tend to confirm that microstrip resonators can be used for dielectric measurements. However, for materials having a large dielectric constant, comparative results seem to diverge rapidly. >

Built-in chip transponder with antenna coil

Abstract: An antenna circuit to be used in conjunction with a chip transponder such that the antenna circuit serves for both the reception of interrogative signals intended for the transponder as well as for response signals that are to be transmitted by the transponder. The antenna circuit has at least one magnetic circuit of high µ material, and is formed of ceramic core means, that have been built into a depression in a thick-walled surface intended to receive the chip transponder. This thick-walled surface may be of metal. The ceramic core means comprise at least a ceramic core resonator (2) and half a ceramic core (3) that functions as an antenna with its open side facing outward. In one aspect, the ceramic core resonator and the half ceramic core antenna are coupled by means of one or more secondary coils of the closed ceramic core, which also form the coils of the half ceramic core antenna. In another aspect, the secondary coil forms a resonating circuit with at least one capacitive element in series. In yet another aspect, the ceramic core resonator and the half ceramic core antenna are formed by one and the same half ceramic core, which may be closed in part by a magnetic covering disk. In yet another aspect, the resonator may consist of a half ceramic core which is placed against the back of the half ceramic core antenna.

A finesse-enhanced Er-doped-fiber ring resonator

Abstract: A two-coupler-type Er-doped-fiber ring resonator that compensates for the round-trip optical loss by optical amplification is proposed. Also proposed is a mode-filtered heterodyne method for resonant-linewidth measurements which does not demand narrow-linewidth light sources, but uses the beat noise between two uncorrelated lights filtered by the resonator passband. With this method, a finesse >or=500 and a resonant linewidth >

Laser system and method

Abstract: A laser system uses a nonlinear ring resonator to produce Type-II nonlinear second harmonic generated light. The reflective surfaces of the resonator are all symmetrical with respect to the crystal axes. This allows orthogonally polarized light to be resonated along the same beampath in the resonator without experiencing bireflection.

Input impedance of hemispherical dielectric resonator antenna

Abstract: A coaxially fed hemispherical dielectric resonator antenna is investigated theoretically. The input impedance of the lowest order TE 111 mode that radiates efficiently in the broadside direction is calculated using the reaction formula. The result is compared with experimental data available in the literature. The erects of the probe length, feed position and dielectric constant on the input impedance are studied

Tunable helical resonator

Abstract: The invention relates to a helix resonator used in particular in filters operating at radio frequency. In instances in which conventional procedures based on adjusting the resonance frequency are not sufficient for tuning the resonator, the procedure of the invention can be used in which the resonator is tuned by adjusting the distance of the ground plane (the wall of the resonator cover (1)) from a leg (4) of the resonator or a lead (3), usually a micro strip, with which the resonator has been connected to an external circuit or to another resonator.

High temperature superconductor support structures for dielectric resonator

Abstract: The invention is directed to a superconducting microwave resonator, to holding devices for those resonators, and to their methods of manufacture. The superconducting microwave resonator employs at least two superconducting films on substrates positioned on a dielectric. The holding devices include a variety of configurations, such as, a spring loaded device. The superconducting microwave resonators have Q values of as high as microwave resonators formed of Nb, but operate at much higher temperature.

Q enhanced dielectric resonator circuit

Abstract: A Q enhanced dielectric resonator circuit includes a metal enclosure having interior walls defining a chamber. Secured to at least two interior walls is a dielectric substrate. Flatly mounted to at least one side of the dielectric substrate is a substrate stripline. A dielectric resonator is secured to the dielectric substrate at a selected distance from the substrate stripline. The dielectric substrate is positioned a sufficient distance from a ground plane such that the magnetic field lines of the dielectric resonator do not significantly interact with the ground plane. The dielectric resonator is also positioned such that there is substantial coupling of the magnetic field lines of the dielectric resonator with the magnetic field lines of the substrate stripline.

Dielectric ring-gap resonator for application in MMIC's

Abstract: A novel dielectric resonator-the dielectric ring-gap resonator- is introduced and analyzed. The resonant frequency and unloaded Q factor of the fundamental quasi-TE/sub 011/ mode have been calculated by a numerical field analysis and an appropriate equivalent circuit. The characteristics of the fundamental quasi-TE/sub 011/ mode in the dielectric ring-gap resonator have been experimentally investigated. New coupling techniques to couple the dielectric ring-gap resonator to, e.g., a microstrip line on a thin substrate, using the electric fringing field near the gap edges have been experimentally investigated. >

Coaxial resonator with distributed tuning capacity

Abstract: This resonator includes one external conductor (20) and one central conductor (10), both conductors having a symmetry of revolution around a given axis (A). The tuning capacitor is fully distributed along the axis of the resonator and includes at least two cylindrical armatures (80, 82, 84) nested into each other and having as an axis the axis (A) of the resonator, one of the two armatures (82) constituting one of the two conductors of the resonator.

Apparatus and method for easily adjusting the resonant frequency of a dielectric TEM resonator

Abstract: A dielectric TEM resonator, whose resonant frequency is adjustable in both directions after being incorporated in a circuit, is disclosed. A first dielectric TEM resonator comprises a metal member disposed near an open end of a resonator body and coupled to an inner or outer conductor of the resonator body. The resonant frequency is adjusted by adjusting a distance between the open end and the metal member. A dielectric material of a second dielectric TEM resonator is partially exposed, and a dielectric board for mounting the resonator body is also exposed in a corresponding part to the exposed part of the dielectric material. The exposed part of the dielectric board is partially covered with a metal plate. The resonant frequency is adjusted by adjusting the covered area.

HTSC inverted and conventional geometry microstrip resonator for UHF frequencies

Abstract: HTSC (high-temperature superconductor) planar resonators may be used to replace voluminous normal conductivity high-Q resonators by miniaturized ones at UHF frequencies (0.3-3 GHz). Therefore an inverted microstrip resonator has been investigated. Both electrodes of the resonator are made of epitaxial films of YBa/sub 2/Cu/sub 3/O/sub 7- delta /, and one of them is structured into a meander-type stripline. The distance between stripline and ground plane is held by a 50- mu m-thick spacer foil which also carries the resonator feeding lines in conventional microstrip design. The small distance between both electrodes ensures that only a small amount of electrical energy is located in the LaAlO/sub 3/ substrates and that the effective dielectric loss factor is low. At 77 K and at a resonant frequency of 700 MHz the measured unloaded Q was 2800. During improving the structuring process and reoptimizing the resonator design, the unloaded Q of the conventional geometry microstrip resonator has been increased to Q/sub 0/=25000. The use of the inverted microstrip resonator design will improve the Q values beyond that.

System for tuning high-frequency dielectric resonators and resonators obtained in this manner

Abstract: In a system for tuning a high-frequency dielectric resonator pair, resonating in the mode TEo1 in frequency bands e.g. from 400 MHz to 20 GHz, preferably from 900 to 4000 MHz, a male dielectric resonator DM, having an external diameter d penetrates into a female dielectric resonator DF, having an external diameter D and a height H; for getting the variations e.g. from 4 to 5% of the tuning frequency within the band from 925 to 970 MHz, the ratio d/D is included between 0.4 and 0.8 and the axial coupling or penetration p/H is included between 0.3 and 0.7 where h is the part of DM engaged axially in DF.

A spectacles-shaped optical fibre ring resonator with two couplers

Abstract: A theoretical study of a novel spectacles-shaped optical fibre ring resonator with double couplers has been carried out. The circulating, transmitted and reflected output fields and intensities have been computed and presented as graphs. The characteristics, advantages and possible applications of this ring resonator are discussed.

Push-push oscillator using a transmission line resonator and differential output

Abstract: A push-push oscillator comprises: a resonator having a transmission line and a capacitance connected to the transmission line in parallel; an oscillator for producing two outputs having an antiphase relation therebetween in response to the resonator; and a differential signal producing circuit for producing a differential signal in accordance with difference between these two outputs. These outputs can be obtained from the resonator. The transmission lines comprise strip line or microstrip line which is curved to form an open loop. The transmission line may be made of a dielectric material and is curved to form an open loop whose both ends are connected to a capacitance. The resonator may further comprise two second transmission lines, each provided to an end of the transmission line, these two second transmission lines facing each other with a given distance therebetween, the distance and length of the second transmission lines being determined such that necessary capacitance is provided. Impedance of each portion of the resonator is determined to miniaturize the resonator. The differential signal producing circuit comprises a balanced to unbalanced converting circuit.

Multi-pole split ring resonator bandpass filter

Abstract: A multipole bandpass filter (40) comprises a first microstrip split-ring resonator (12), having at least a first edge and a second edge, the first edge having a gap (20) therein, and an input. The bandpass filter (40) also comprises a second microstrip split-ring resonator (14), having at least a first edge and a second edge, the second edge of the second microstrip split-ring resonator comprising a gap (26) therein and a balanced output (30, 32). The bandpass filter also includes at least one straight line quasi-combline resonator (22), disposed between the first microstrip split-ring resonator, and the second microstrip split-ring resonator.

Voltage controlled oscillator having a resonator

Abstract: A voltage controlled oscillator having a resonator wherein a substrate is made up of a plurality of dielectric layers; an inductor functioning conductive film and grounding electrode films are each formed at a boundary surface of one of the dielectric layers; the earth electrode films are arranged, in the direction in which the dielectric layers are laminated, at both sides of the conductor functioning conductive film; the inductor functioning conductive film and the grounding electrode films constitute the resonator; and electric lands are formed on the surface of the substrate so that other components of the oscillator are mounted on the surface of the substrate.

Low-loss dielectric resonator having a lattice structure with a resonant defect

Abstract: A dielectric resonator comprising a resonant defect structure disposed in a lattice structure formed of a plurality of multi-dimensional periodically arranged dielectric elements confines electromagnetic energy within a frequency band in the photonic band gap. The frequency band of the confined electromagnetic energy is tunable. The unique structure of the dielectric resonator leads to reduced power dissipation losses when used in microwave and millimeter wave components. Accordingly, the dielectric resonator BACKGROUND This invention was made with government support under Contract Number N00014-86-K-0158 awarded by the Department of the Navy and Contract Number DAAL-03-86-K-0002 awarded by the Department of the Army. The government has certain rights in the invention.

Resonator for hermetic rotary compressor.

Abstract: A resonator of a hermetic rotary compressor in which noise is reduced to a maximum extent by effectively absorbing high frequency pressure components inside a cylinder of the compressor. The resonator comprises a resonator space of bi-level configuration disposed between a bearing flange and a matching cylinder face surface. This resonator space communicates with a discharge part defined in the compressor through an entrance channel which has a tapered surface to form a narrow inlet and a wide outlet. With this construction, the resonator effectively reduces the high frequency component out of gas pulsation generated in the cylinder.

Thermoacoustic sound generator

Abstract: A submersible acoustic generator for projection of sound waves into a bodyf water comprises a tubular resonator, open at its lower end and closed at its upper end, and having a multiple-plate thermoacoustic stack located near the upper end between a pair of heat exchangers which set up a temperature gradient in the stack. The upper heat exchanger is heated by a chemical fuel, and the lower heat exchanger is cooled by the surrounding water. The resonator is gas-filled, and the wavelength of the oscillations produced is approximately twice the length of the resonator. A portion of the resonator tube can be surrounded by a coaxial tube which serves as an impedance matching stub. The stack plates can be made anisotropic by means of embedded copper wires. In alternative versions of the apparatus, the resonator can have two stacks, one near the open end and the other near the closed end, and the temperature gradient in the stack can be established cryogenically.

Apparatus for the production of a regular microwave field

Abstract: The invention relates to an apparatus for the production of a regular microwave field over a comparatively great area. This apparatus has a cavity resonator into which microwaves are put. Electromagnetic energy is coupled by special couplers, inductively or capacitively, out of the standing waves forming in the cavity resonator into a chamber in which preferably a plasma is contained.

Dielectric block filter with included shielded transmission line inductors

Abstract: In those monolithic ceramic filters that require resonator stages formed within a block of dielectric material to be electrically coupled together through discrete components, namely wires (44 and 46), a substantial space savings as well as improved electrical and mechanical performance can be realized by mounting the wires (44 and 46) within de-coupling cavities (36 and 40) when such de-coupling cavities are available and properly positioned with respect to the other resonator elements in the filter.

Novel large mode volume resonator

Abstract: A resonator in which the dominant mode-shaping effect is diffraction from an undersized aperture is reported. The result is a large mode volume and a near diffraction-limited Gaussian output beam. The alignment sensitivity is similar to that of a positive branch unstable resonator, although the mirror configuration can vary over a large range in either the geometrically stable or unstable regimes. A pulsed Nd:YAG laser using this resonator was built and characterized in the free-running, Q-switching, and mode-locking regimes, and as a regenerative amplifier. >

Dielectric resonator and a filter using same

Abstract: A dielectric resonator (38) with a dielectric block (30). The block has a plurality of resonance apertures (32) and coupling-prevention aperture (34) between the adjacent resonance apertures within the block. The block is entirely coated with a conductive film except a limited portion around the one end of the resonance apertures.

Numerical studies of resonators with on-axis holes in mirrors for FEL application

Abstract: An optical resonator with holes on-axis for applications in a FEL oscillator was recently proposed by Pantell et al. [Nucl. Instr. and Meth. A296 (1990) 638]. These authors presented an analytical approach based on approximating the field inside the resonator by a truncated expansion in Gauss-Laguerre modes. We perform further investigation of this configuration by using a Fox and Li type code which was recently applied to the analysis of a laser resonator with internal circular aperture. This numerical approach allows us to check the range of validity of Pantell's solutions, the parameters for which they constitute the lowest-loss mode and to map the transverse profile of the mode at different planes inside the resonator.

An investigation of the travelling wave dielectric resonator for applications to electron spin resonance experiments

Abstract: A travelling wave dielectric disc resonator has been investigated and used the detection of ESR signals of small samples, in the frequency range 18 to 26.5 GHz. A spectrometer having the sensitivity of 5*1010 spins 10-4T-1 at room temperature featuring an all-dielectric probe head is presented. Preliminary results and a discussion on the possible developments of the new technique are given.

Quartz crystal oscillators with direct resonator heating

Abstract: The authors describe a novel low-power, ovenized oscillator with the crystal heated directly by means of a thin-film resistive heater deposited on its surface. The only significant path for heat loss is through the resonator mounting ribbons and posts, and these, being long and thin, have quite high thermal resistance. Pulse duration modulation controls resonator heating current. Phase noise, Allan variance, and aging all appear unaffected by direct resonator heating. Frequency-temperature stability better than +or-2.5*10/sup -8/ from 0 to 70 degrees C has been achieved using a third overtone 10.230-MHz SC-cut resonator with room-temperature power consumption of about 300 mW. Theoretical analysis shows substantial heating power reduction is possible by introducing additional thermal resistance in the form of a glass ring as part of the resonator mounting structure. >

High-frequency band-pass filter having multiple resonators for providing high pass-band attenuation

Abstract: A high-frequency band-pass filter has an input resonator, a middle resonator and an output resonator which are coupled in parallel. The input resonator and the output resonator are capacitively shortened quarter-wave line resonators. To improve the attenuation characteristics, the middle resonator is designed as a capacitively shortened half-wave resonator. The input resonator extends along a first part of the length of the middle resonator. The output resonator extends along a second part of the length of the middle resonator.

Computer-controlled system for surface resistance measurements of HT/sub c/ superconducting films

Abstract: A measurement system capable of determining the microwave surface resistance of high-temperature superconducting films is described. The measurement is based on evaluating the resonant curve of a circular cylindrical waveguide transmission resonator. The cylindrical wall, and the top plane of the resonator are made of copper. The test sample is the ground plane of the resonator. The surface resistance of the test sample can be directly evaluated from the quality factor of the resonator when the surface resistance of copper is used as a reference. The computer-controlled measurement system consists of a backward-wave oscillator, the cylindrical resonator, a spectrum analyzer for the detection of power and frequency, and a refrigerator for cooling the resonator and the test sample. Several measurements have been made. Surface resistances of different thin-film samples have been determined. The lowest values measured so far approximate 25 m Omega at 66.8 GHz and 77 K. >