Showing papers on "Dielectric resonator antenna published in 2004"

Dielectric-resonator array antenna system

Abstract: A dielectric resonator element array (DRA) antenna system that is small, compact, has high gain in the direction of intended communication, minimized interference in unintended directions of communication and a wide bandwidth. The antenna system comprises a ground plane, a feed structure, a beam shaping and steering controller, a mounting apparatus, an array of dielectric resonator elements and a radome that is close to or in contact with the array. The mounting apparatus preferably is configured so as not to appreciably increase the size of the system when mounted. The controller receives and processes information relating to one or more of object latitude, longitude, attitude, direction of travel, intended direction of communication and unintended directions of communication. The controller processes this information and determines excitation phase for the array elements.

Dielectric antenna with increasing cross-section

Abstract: A solid dielectric resonator antenna comprises a block of solid dielectric material 14, 40, mounted on a generally planar substrate 12, 42. The solid dielectric material has a dielectric constant in the range from 10-90. The cross-sectional area of the block of solid dielectric material in a plane parallel to the plane of the substrate increases, either linearly or in a stepwise manner, with increasing distance from the substrate. The block of solid dielectric material 14, 40 may be a single body or it may be made up differently-sized individual blocks or discs. The antenna may form part of an array of similar antennae (fig. 5).

Antenna for mobile communication terminals

Abstract: An antenna comprising: a first substantially planar ground plate; a first substantially planar resonator positioned in a plane substantially parallel to the first ground plate; a second substantially planar ground plate positioned in a plane substantially parallel to the first ground plate; two or more connectors for electrically connecting the second ground plate to ground; and one or more connectors for electrically connecting the first resonator to the second ground plate; wherein the first resonator and the second ground plate are connected to at least one of receiver means and transmitter means by antenna feeding means

RFID devices having self-compensating antennas and conductive shields

Abstract: A radio frequency identification (RFID) tag includes an antenna configuration coupled to an RFID chip, such as in an RFID strap. The antenna configuration is mounted on one face (major surface) of a dielectric material, and includes compensation elements to compensate at least to some extent for various types of dielectric material upon which the antenna configuration may be mounted. In addition, a conductive structure, such as a ground plane or other layer of conductive material, may be placed on a second major surface of the dielectric layer, on an opposite side of the dielectric layer from the antenna structure.

Hybrid dielectric resonator antennas with radiating slot for dual-frequency operation

Abstract: To achieve dual-frequency operation, a new design concept that utilizes a hybrid structure that includes a dielectric resonator antenna (DRA) and a slot radiating resonator was investigated experimentally. The proposed structure consists of a DRA, a circular slot and an eccentric ring slot on a co-plane ground plane. This arrangement can be described as two cascaded resonant circuits that resonate at two different frequencies. One is from the DRA and the other from the ring slot. Based on the proposed design concept, a number of phototypes have been successfully designed, fabricated and tested. The measured results have demonstrated the validity of the proposed design.

Film bulk acoustic resonator and film bulk acoustic resonator circuit

Abstract: In a film bulk acoustic resonator, a multi-layered member is placed on a substrate. The multi-layered member has: a common electrode; a piezoelectric layer formed on the common electrode; a first electrode which is formed on the piezoelectric layer, and which is used for a resonator; a second electrode which surrounds the edge of the first electrode with forming a gap therebetween, and which is used for a spurious suppressing element; a first wiring through which an electric power is supplied to the first electrode; and a second wiring through which an electric power is supplied to the second electrode. In the film bulk acoustic resonator, the piezoelectric layer includes a ferroelectric film, and a polarization state of the ferroelectric film corresponding to the resonator is different from a polarization state of the ferroelectric film corresponding to the spurious suppressing element.

Wideband flipped staired pyramid dielectric resonator antennas

Abstract: A wideband aperture coupled flipped staired pyramid shaped DRA is presented. An impedance bandwidth of 62% (S/sub 11/<-10 dB) is measured. The proposed DRA has a stable broadside radiation pattern across the matching band, with an average gain of 6.5 dBi. Simulation results obtained from Fidelity give good agreement with measured results.

Multimode dielectric resonator antenna of very high permittivity

Abstract: In this paper a design strategy to obtain low loss, small size dielectric antennas, by using very high dielectric constant materials is described. It is shown how by properly selecting the resonator shape and combining different resonant modes it is possible to design dielectric resonator antennas (DRA) with compact size and wide frequency coverage even at the cellular frequencies. Simple formulas are presented to illustrate the design procedure and allow a quick dimensioning of the antenna. Furthermore the paper describes techniques to enhance the response provided by the natural resonance frequencies of DRA, by adding parasitically coupled conducting strips, to enable multi-band operation. Results and examples are reported, showing the effectiveness of the proposed technique.

Broadband complex permittivity measurements of dielectric substrates using a split-cylinder resonator

Abstract: We discuss a theoretical model describing the split-cylinder resonator for non-destructive measurement of a dielectric substrate's relative permittivity and loss tangent. This improved model properly accounts for the fringing electric and magnetic fields in the dielectric substrate. Previously, the split-cylinder resonator has been used for single-frequency permittivity and loss tangent measurements using only the fundamental TE/sub 011/ resonant mode. By including high-order TE/sub 0np/ modes, we demonstrate how to measure the relative permittivity and loss tangent of dielectric substrates over an extended frequency range. We validated the new model by measuring the permittivity and loss tangent of fused-silica substrates from 10 to 50 GHz and comparing with results obtained with circular-cylindrical cavity, a dielectric-post resonator, and several split-post resonators.

Multiband antenna with parasitically-coupled resonators

Abstract: A multiband antenna includes at least two resonators that are driven directly and resonate in different frequency bands and a parasitically coupled resonator that resonates in one of the frequency bands. The coupled resonator is grounded with a conductive trace at one end and is thus not directly fed by the RF feed of the antenna. The coupled resonator increases the efficiency bandwidth near the frequency of operation for the coupled resonator. The antenna is fabricated from a stamped metal that is bent around or overmolded by a spacer layer. A clip formed integrally with the antenna by bending a portion of the ground plane permits attachment to the metal shield of the display of a laptop computer and is thus grounded along its length.

Current noise of a single-electron transistor coupled to a nanomechanical resonator

Abstract: The current noise spectrum of a single-electron transistor (SET) coupled to a nanomechanical resonator is calculated in the classical regime. Correlations between the charge on the SET island and the position of the resonator give rise to a distinctive noise spectrum which can be very different from that of the uncoupled SET. The current noise spectrum of the coupled system contains peaks at both the frequency of the resonator and double the resonator frequency, as well as a strong enhancement of the noise at low frequencies. The heights of the peaks are controlled by the strength of the coupling between the SET and the resonator, the damping of the resonator, and the temperature of the system.

Circularly polarized dielectric resonator antenna excited by a shorted annular slot with a backing cavity

Abstract: Excitation of the circularly polarized dielectric resonator antenna (DRA) using a shorted annular slot is studied in this paper The new method is demonstrated using a hemispherical DRA The exact DRA Green's function is used in the formulation, and the method of moments is employed to solve for the equivalent magnetic current in the slot The input impedance, axial ratio, and field patterns are found Measurements were carried out to verify the calculations, with good results The effects of the radius and shorting width of the slot are investigated, and the design procedure of the CP DRA is discussed

Numerical simulation of an optical resonator for generation of a doughnut-like laser beam

Abstract: A design of an optical resonator for generation of a doughnutlike laser beam in the far field is proposed. The resonator consists of a toric mirror, a flat output coupler, and a w-axicon with a movable center axicon. Two-dimensional vector electric field simulation has shown that any one of the Laguerre–Gaussian modes can be selected by sliding the center axicon. Therefore this resonator is capable of generating doughnut-like laser beams, whose dark spot size can be controlled in real time. This feature of the proposed resonator is advantageous for atom trapping and optical tweezers.

New ring resonator configuration using hybrid photonic crystal and conventional waveguide structures.

Abstract: We propose a new method of realizing ring resonators based on hybrid photonic crystal and conventional waveguide structures. The proposed ring resonator configuration is advantageous compared with general ring resonator structures for its controllability of the quality (Q) factor, free spectral range (FSR), and full width at half maximum (FWHM) over a wide range. We show ring resonator structures based on a single mode waveguide with core and clad refractive indices of 1.5 and 1.465, respectively. A 35µm×50µm ring resonator has a free spectral range (FSR) of 14.1nm and a quality (Q) factor of 595 with high optical efficiency (92.7%). By decreasing the size of the ring resonator to 35µm×35µm, the FSR is increased to 19.8nm. Modifying the splitting ratio of the beam splitters permits the Q factor to be increased to 1600.

Resonator system with a plurality of individual mechanically coupled resonators and method of making same

Abstract: A resonator system wherein a plurality of resonators each including piezoelectric material are suspended relative to a substrate. An edge of each resonator is mechanically coupled to an edge of another resonator and the plurality of resonators expand and contract reaching resonance in response to an applied electric field.

Analysis of Circularly Polarized Dielectric Resonator Antenna Excited by a Spiral Slot

Abstract: The hemispherical dielectric resonator antenna (DRA) excited by a single-arm spiral slot is studied theoretically in this paper. The Green’s function technique is employed to formulate an integral equation for the spiral slot current. The moment method with piecewise sinusoidal (PWS) basis and testing functions is used to convert the integral equation into a matrix equation by using a deltagap exciting source. The input impedance, return loss, axial ratio and radiation pattern are calculated. Numerical results demonstrate that the analysis is efficient.

Spherical Bragg reflector resonators

Abstract: In this paper we introduce the concept of the spherical Bragg reflector (SBR) resonator. The resonator is made from multiple layers of spherical dielectric, loaded within a spherical cavity. The resonator is designed to concentrate the energy within the central region of the resonator and away from the cavity walls to minimize conductor losses. A set of simultaneous equations is derived, which allows the accurate calculation of the dimensions of the layers as well as the frequency. The solution is confirmed using finite-element analysis. A Teflon-free space resonator was constructed to prove the concept. The Teflon SBR was designed at 13.86 GHz and exhibited a Q-factor of 22,000, which agreed well with the design values. This represents a factor of 3.5 enhancement over a resonator limited by the loss-tangent of Teflon. Similarly, SBR resonators constructed with low-loss materials could achieve Q-factors of the order of 300,000.

Film bulk acoustic resonator having supports and manufacturing method therefore

Abstract: A film bulk acoustic resonator (FBAR) has a support structure, a piezoelectric resonator, and a signal line that is electrically connected, e.g., through a via, to the piezoelectric resonator, all on a semiconductor substrate. Support(s) and/or the via mount the piezoelectric resonator at a predetermined distance from the semiconductor substrate, allowing an ideal shape of the resonator to be realized. The signal line may include a patterned inductor. A capacitor can be formed between the via and the signal line. The resonance characteristics can be enhanced since the substrate loss caused by the driving of the resonator can be prevented due to an air gap formed by the predetermined distance. The resonance frequency can be adjusted by altering the pattern of the inductor, the capacitance of the capacitor and/or the thickness of the piezoelectric layer, also allowing Impedance matching to be readily realized.

Dual-mode double-ring resonators for microstrip band-pass-filter applications

Abstract: A novel design of a dual-mode resonator with a double-ring structure for band-pass filter applications is presented in this paper. Conventionally, dual-mode ring resonators are used to obtain band-pass filters. Based on voltage/current couplings, a dual-mode double-ring resonator was recently constructed to improve the responses of the conventional dual-mode ring resonator. In order to obtain a low insertion loss, a wide band and higher rejection, three filters using a dual-mode double-ring resonator are designed for 2.4 GHz ISM band applications.

Filter using multilayer ceramic technology and structure thereof

Abstract: The present invention discloses a filter using multilayer ceramic technology. The filter comprises an input port, an output port, a first lumped resonator and a first step-impedance resonator connected to the input port, a second lumped resonator and a second step-impedance resonator connected to the output port, a coupling capacitor used for the coupling of the first lumped resonator and the first step-impedance resonator to the second lumped resonator and the second step-impedance resonator. The filter according to the present invention can provide the multi-transmission zeros in the stopband to isolate the adjacent channel and suppress the harmonics, and provide the transmission poles in the passband to have lower insertion loss. In addition, a manufacturing method for the filter using multilayer ceramic technology is also disclosed.

Radial bragg ring resonator

Abstract: A resonator structure is presented comprising a closed loop resonator having a distributed Bragg reflector for confining the light within the guiding core. In one embodiment the light is confined from both the internal and the external sides of the device forming a guiding channel (defect) or just by the external side forming a disk resonator. Although the perfectly circular shape is generally preferred, the resonator could be of any closed loop shape such as an ellipse, etc. Although not mentioned explicitly throughout the text, the Bragg reflectors can of any type of distributed reflector such as, for example, a photonic bandgap crystal where the Bragg reflector is constructed by series of holes in a dielectric material. The resonator structure can be used in various applications, such as optical filters, lasers, modulators, spectrum analyzers, wavelockers, interleave filters, and optical add drop multiplexers.

Determination of dielectric constant and dissipation factor of a printed circuit board material using a microstrip ring resonator structure

Abstract: A microstrip ring resonator structure is used to determine the dielectric constant and dissipation factor of FR-4 type printed circuit board material. The article presents essential information on the microstrip ring resonator measurement method, characteristics of the microstrip line losses, and dielectric constant and dissipation factor calculation techniques. Based on the presented information, the dielectric properties of high loss printed circuit board materials can be determined for a wide frequency band.

Mems type resonator, process for fabricating the same and communication unit

Abstract: A MEMS resonator and a method for manufacturing thereof are provided, in which an adsorption of a beam into a substrate in a wet process when manufacturing a MEMS is prevented and other oscillation modes, which are unnecessary, than a required oscillation mode are not mixed at the time of operation. Further, a communication apparatus including a filter that has the MEMS resonator is provided. The MEMS resonator includes a substrate in which a lower electrode is formed and a beam formed on the substrate, in which at least one support column is provided between the substrate and the beam. As a filter, the communication apparatus includes a filter of the above MEMS resonator.

Hybrid triple-mode ceramic/metallic coaxial filter assembly

Abstract: A hybrid filter assembly is provided having a first ceramic triple-mode mono-block resonator, a second ceramic triple-mode mono-block resonator and at least one metallic resonator coupled to at least one of the first and second mono-block resonators. Each triple-mode mono-block resonator supports three resonant modes and each metallic resonator supports an additional mode, thereby providing a hybrid filter assembly of reduced size having more than six poles.

High gain resonant modulator system and method

Abstract: An optical resonant modulator includes an optical ring resonator and an optical loop that is coupled to the optical ring resonator by two couplers. The optical ring resonator can have a hybrid design in which the ring resonator is formed on an electro-optically passive material and the optical loop is formed on an electro-optically active material. An amplification section can be inserted between the electro-optically passive and the electro-optically active sections. In analog applications, an optical resonator includes a Mach Zehnder interferometer section having an input and an output, with a feedback path coupling the output to the input. Applications of the optical modulator of the invention, and a method for modulating an optical signal also are disclosed.

A tunable split resonator method for nondestructive permittivity characterization

Abstract: The split cylinder resonator method is improved for nondestructive and accurate measurement for low permittivity materials at multiple frequency points. The dielectric constants of flat substrate materials are calculated based on a rigorous mode match analysis of the TE/sub 011/ mode. The loss tangent is also approximately calculated. The dielectric properties of two commercial substrates have been measured at multiple frequencies. The results demonstrate that this technology is capable of accurately characterizing the dielectric properties of flat substrate materials versus frequency in a nondestructive way.

Filter using piezoelectric resonator

Abstract: A series piezoelectric resonator is connected in series between an input terminal and an output terminal. A first electrode of a first parallel piezoelectric resonator is connected to a connection point between the input terminal and the series piezoelectric resonator, and a second electrode of the first parallel piezoelectric resonator is connected to a first terminal of a first inductor. A first electrode of a second parallel piezoelectric resonator is connected to a connection point between the series piezoelectric resonator and the output terminal, and a second electrode of the second parallel piezoelectric resonator is connected to a first terminal of a second inductor. Second terminals of the first and second inductors are grounded. An additional piezoelectric resonator is connected between the second electrode of the first parallel piezoelectric resonator and the second electrode of the second parallel piezoelectric resonator.

Array of perforated dielectric resonator antennas

Abstract: An array of dielectric resonator antenna (DRA) elements is formed by perforating a dielectric substrate with a lattice of holes. The performance of a small prototype array designed at 25 GHz was investigated. Measured results agree with theoretical values based on an array fabricated using conventional DRA. This technique of fabricating DRA using perforations eliminates the need to position and bond individual elements in an array.

Laser diode arrangement with external resonator

Abstract: In a laser diode arrangement for generating single mode tunable laser radiation wherein the laser diode forms a first resonator and has rear and front facets and a second external resonator is coupled to the first resonator, and an optical transmission component and a wavelength selective optical reflection element are arranged in the laser light path from the laser diode for directing part of the laser light into the external resonator and coupling it back into the first resonator, means are provided for changing the coupling quality of the first resonator to the external, second resonator.