Showing papers on "Dielectric resonator antenna published in 2002"

Conical dielectric resonator antennas for wide-band applications

Abstract: Wideband dielectric resonator antennas are designed by shaping the dielectric materials. New dielectric resonator antennas of conical shape are experimentally examined and some results are verified numerically. Four different cone shapes are considered. The excitation is considered to be a coaxial probe displaced from the cone axis. Two configurations show wideband performance. The split cone achieved about 50% impedance bandwidth. The radiation patterns are computed within the band to examine the effect of the different modes excited on the radiation patterns.

An electromagnetic bandgap resonator antenna

Abstract: This paper introduces a new explanation of the electromagnetic bandgap (EBG) material properties using the study of the EBG structures in the frequency domain and reciprocal space. Once the behavior of such a material is understood, the properties of the EBG are used in order to make an EBG antenna. The antenna is realized with dielectric EBG rods. Its directivity is increased compared to a simple patch antenna. Such a device allows us to obtain a high gain with a very thin structure.

Dielectric resonator antenna with mutually orthogonal feeds

Abstract: A multi-polarisation dielectric resonator antenna (1) having three mutually orthogonal feeds (5a, 5b, 5c) displaying C3v point group symmetry is disclosed. The antenna (1) may be operated so as to determine the polarisation of any incoming signal, since the three feeds (5a, 5b, 5c) have polarisations at 120 degrees to each other. Furthermore, a plurality of multi-polarisation dielectric resonator antennas (1) may be formed into a composite dielectric resonator antenna with beamsteering, direction finding and polarisation detection capability over a full 4π steradians.

Coplanar-waveguide-fed slot-coupled rectangular dielectric resonator antenna

Abstract: A novel coupling scheme to a rectangular dielectric resonator antenna is proposed and investigated. In particular, coupling to the resonator is achieved through a narrow slot at the end of a coplanar waveguide (CPW). The objectives of this design are to maximize the coupling, match the dielectric resonator to the CPW feed line, achieve resonance at the desired frequency, obtain linear polarization with low cross polarization components, and minimize back radiation without using a back conductor. An approximate and quick design approach is given followed by more accurate design and analysis using commercial software. The antenna was fabricated and tested. Measurements match well with simulation results.

A tunable ferroelectric resonator arrangement

Abstract: The present invention relates to a tunable resonating arrangement comprising a resonator apparatus (10), input/output coupling (4) means for coupling electromagnetic energy into/out of the resonator apparatus, and a tuning device (3) for application of a biasing voltage/electric field to the resonator apparatus. The resonator apparatus comprises a first resonator (1) and a second resonator (2). Said first resonator is non-tunable and said second resonator is tunable and comprises a ferroelectric substrate (21). Said first and second resonators are separated by a ground plane (13) which is common for said first and second resonators, and coupling means (5) are provided for providing coupling between said first and second resonators. For tuning of the resonator apparatus, the biasing voltage/electric field is applied to the second resonator (2).

A compact-size microstrip spiral resonator and its application to microwave oscillator

Abstract: This letter presents a compact size microstrip spiral resonator and its application to a low phase noise oscillator. This resonator has stopband characteristics to be used in the series feedback oscillator topology. The whole circuit area of the proposed resonator is within 1/10 wavelength, which results in the reduction of the circuit area and cost. A 10-GHz oscillator incorporated with this resonator was designed, fabricated and measured. It shows low phase noise performance of -95.4-dBc/Hz at 100 kHz offset.

Radio frequency filter, radio frequency circuit, antenna duplexer and radio terminal

Abstract: A radio frequency filter that can be miniaturized is provided. The radio frequency filter has a ladder-type resonator filter, a first terminal, a second terminal, a serial capacitance, a parallel capacitance, a serial inductance, and a parallel inductance. In the ladder-type resonator filter, a plurality of first surface acoustic wave resonators or first film bulk acoustic resonators are connected in a ladder circuit configuration. The serial inductance and the parallel capacitance are connected between the ladder-type resonator filter and the first terminal. The serial capacitance and the parallel inductance are connected between the ladder-type resonator filter and the second terminal.

Mechanical resonator device having phenomena-dependent electrical stiffness

Abstract: A mechanical resonator device (10) which has a phenomena-dependent electrical stiffness is provided. The phenomena may be temperature or acceleration, for example. The device includes a substrate (16) and a resonator (14) supported above the substrate by supports. The device further includes an electrode (12) supported above the substrate (16) adjacent the resonator by supports (18) to obtain an electrode-to-resonator gap wherein electrical stiffness generated across the gap is phenomena-dependent to take instability of resonant frequency of the device caused by the phenomena into consideration.

Tunable superconductor resonator

Abstract: A tunable superconductor resonator including a superconductor resonator coil and a variable capacitance portion. The superconductor resonator is adjustable to a first resonant frequency and a second resonant frequency. A variable capacitance portion is electrically coupled to the superconductor resonator coil to vary electrical capacitance between a first capacitance and a second capacitance. The variable capacitance portion providing the first capacitance adjusts the superconductor resonator to its first resonant frequency. The variable capacitance portion providing the second capacitance adjusts the superconductor resonator to its second resonant frequency. Different aspects of the tunable superconductor resonator can be tuned using dynamic tuning and/or static tuning techniques.

Isolated resonator gyroscope

Abstract: The present invention discloses a resonator gyroscope comprising a resonator including two bodies (102, 104), each with a center of mass and transverse inertia symmetry about an axis that are substantially coincident and each supported by one or more elastic elements (108) and wherein the bodies together forming two differential rocking modes of vibration transverse to the axis with substantially equal frequencies and wherein the two bodies transfer substantially no net momentum to the baseplate (106) when the resonator is excited. The gyroscope further includes a baseplate (106) affixed to the resonator by the one or more elastic elements (108) and sense and drive elements each affixed to the resonator and baseplate.

Steerable-beam multiple-feed dielectric resonator antenna

Abstract: A radiating antenna capable of generating or receiving radiation using a plurality of feeds and a dielectric resonator is disclosed. The purpose of using multiple feeds with a single dielectric resonator antenna is to produce several beams each having a ‘boresight’ (that is, a direction of maximum radiation on transmit, or a direction of maximum sensitivity on receive) in a different direction. Several such beams may be excited simultaneously to form a new beam in any arbitrary direction. The new beam may be incrementally or continuously steerable and may be steered through a complete 360 degree circle. The invention may be combined with an internal or external monopole antenna so as to cancel out the antenna backlobe or otherwise resolve the front/back ambiguity that arises with this type of dielectric resonance antenna. When receiving radio signals, electronic processing of such multiple beams may be used to find the direction of those signals thus forming the basis of a radio direction finding device. Further, by forming a transmitting beam or resolving a receiving beam in the direction of the incoming radio signal, a ‘smart’ or ‘intelligent’ antenna may be constructed. The excitation of several beams together can, in some combinations, produce a system with a significantly greater bandwidth than a beam formed by exciting a single probe or aperture. The dielectric resonator is mounted on a ground plane, is preferably substantially cylindrical, and is fed, for example, by a number of internal probes or external ground plane apertures. An internal or external monopole antenna may be added to improve performance.

Dielectric filter, antenna duplexer

Abstract: A dielectric filter includes resonator electrodes, an inter-stage coupling capacitor electrode, and an input/output coupling capacitor electrode on dielectric substrates, respectively. The resonator electrodes are electro-magnetically coupled to each other to form a tri-plate structure, are made of a metallic foil embedded in a resonator dielectric substrate. Another dielectric filter includes an upper shield electrode dielectric substrate, an inter-stage coupling capacitor dielectric substrate, a resonator dielectric substrate, and an input/output coupling capacitor dielectric substrate which are made of a composite dielectric material including a high-dielectric-constant material and a low-dielectric-constant material. The above described arrangement provides the dielectric filter with an improved Q factor of a resonator, a low loss, and a high attenuation.

A small dielectric resonator antenna

Abstract: By covering a cylindrical dielectric resonator antenna with a metallic cap, the resonant frequency of the antenna can be reduced by 30.6%. The result finds applications in designing small antennas for wireless communication systems.

Wideband disc‐ring dielectric resonator antenna

Abstract: A dielectric resonator excited by a coaxial probe and designed for an omni-directional pattern is considered. Combining two dielectric resonators of different dielectric material with each other enhances bandwidth. The effect of antenna parameters such as dielectric constant and probe length are investigated. The analysis is performed numerically, using the method of moments and verified by the FDTD method. The agreement between the two methods is excellent. A 45% bandwidth is achieved with this structure. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 425–428, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10628

Tetrahedron and triangular dielectric resonator antenna with wideband performance

Abstract: Dielectric resonator antennas are found to be an efficient radiator. In the search for dielectric resonators with wideband performance, different DRA shapes have been investigated. It is found that some geometries have a wider bandwidth or better polarization characteristics than others. We consider the truncated tetrahedron geometry. Three different configurations are considered. The first is with the wide base of the truncated tetrahedron attached to the ground plane and the second is with the narrow base attached to the ground plane. The third case is the triangular cylinder as a special case of the truncated tetrahedron. Different excitation mechanisms can be used to excite the DRA. We use coaxial probe excitation.

Resonance Frequency Tuning of a Double Ring Resonator in GaInAsP/InP: Experiment and Simulation

Abstract: A racetrack shaped double ring resonator (DRR) filter is demonstrated with radii of 200 µm. The double ring resonator contains two -3 dB multimode interference (MMI) couplers for I/O coupling and a -13 dB codirectional coupler in between the rings. A free spectral range of 50 GHz has been realized. A simulation model has been developed to describe the DRR. As fabrication tolerances do not allow the realization of two identical rings with required nm-circumference accuracy in the resonator, a frequency alignment of the resonator is indispensable. The resonance frequency tuning is performed thermally using platinum resistors which have been placed on top of the waveguides in both rings. An on-off ratio increase has been achieved of more than 3 dB, resulting in a total on-off ratio larger than 18 dB. The frequency alignment is inevitable in the case of multiple coupled micro ring resonators.

Perforated dielectric resonator antennas

Abstract: A dielectric resonator antenna (DRA) is formed by perforating a dielectric substrate with a lattice of holes. The performance of several perforated DRA prototypes is compared to a conventional DRA and the results demonstrate better gain and cross-polarisation levels. This technique of fabricating DRAs using perforations is intended for array applications, eliminating the need to position and bond individual elements.

Enhanced bandwidth microstrip patch antennas loaded with high permittivity dielectric resonators

Abstract: A novel technique for the bandwidth enhancement of conventional rectangular microstrip antenna is proposed in this paper. When a high permittivity dielectric resonator of suitable resonant frequency was loaded over the patch, the % bandwidth of the antenna was increased by more than five times without much affecting its gain and radiation performance. A much more improved bandwidth was obtained when the dielectric resonator was placed on the feedline. Experimental study shows a 2:1 VSWR bandwidth of more than 10% and excellent cross polarization performance with increased pass band and radiation coverage almost the same as that of rectangular microstrip antenna. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 327–330, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10597

Thin-film piezoelectric resonator, band-pass filter and method of making thin-film piezoelectric resonator

Abstract: A thin-film piezo-resonator includes a silicon substrate and a resonator assembly. The substrate is formed with a cavity or through-hole which is opened in the upper and the lower surfaces of the substrate. The resonator assembly, disposed at a location corresponding to the cavity, is composed of a first electrode contacting the upper surface of the substrate, a piezoelectric layer formed on the first electrode and a second electrode formed on the piezoelectric layer. The cavity has a side surface extending in a substantially perpendicular direction to the first surface.

Tuneable dielectric resonator

Abstract: A method of tuning a dielectric resonator uses a ferroelectric element to change the dielectric resonator electric field and hence the resonance frequency of the dielectric resonator.

Method of implementing the Kerr effect in an integrated ring resonator (the Kerr Integrated Optical Ring Filter) to achieve All-Optical wavelength switching, as well as all-optical tunable filtering, add-and -drop multiplexing space switching and optical intensity modulation.

Abstract: The present invention relates to an integrated optical ring resonator waveguide surrounded by an upper bus and a lower bus waveguide. A first resonant and intense optical wave is coupled into the upper bus whereas a second resonant optical wave is coupled into the lower bus. These resonant waves propagate from one bus to the other through the resonator in opposite directions. The first wave modulates the core refractive index of the resonator (Kerr effect) and thereby shifts the resonant conditions of the resonator. This results in the amplitude modulation of the second wave at its non-resonant port. Through this process, the optical amplitude modulation pattern of the first wave is transferred to the second wave. Optical wavelength switching is achieved when the waves have different wavelengths. In alternative embodiments and methods of driving the resonator, the resonator can achieve filtered wavelength tuning, add-and-drop multiplexing, space switching and intensity modulation.

Circularly polarised dielectric resonator antenna with metallic strip

Abstract: A new design of circularly polarised slot fed dielectric resonator antenna (DRA) is presented. The dissymmetry of the design enabling circular polarisation relies on a metallic strip printed on top of the resonator. Simulations are compared with measurements for a single antenna as well as a four DRA sequential rotation array.

Filter technique for increasing antenna isolation in portable communication devices

Abstract: Provided is a system and method for reducing the effects of antenna coupling by increasing the isolation between closely mounted antennas on a portable wireless communications device. Increased isolation is achieved by providing a ceramic resonator in the path of each of the antennas. The ceramic resonator placed in the path of a particular antenna reduces the effects of coupling caused by a particular one of the other antennas by rejecting signals associated with the particular antenna.

Filter using film bulk acoustic resonator and transmission/reception switch

Abstract: A transmission band filter (110) having a series of elements (111, 113, 115) each composed of a film bulk acoustic resonator and grounded shunt elements (112, 114) is connected between a transmission port (102) and an antenna port (106). A reception band filter (130) having a series of elements (131, 133, 135) each composed of a film bulk acoustic resonator and grounded shunt elements (132, 134, 136) is connected between a reception port (104) and the antenna port (106). A film bulk acoustic resonator (150) for adjustment is connected between the antenna port (106) and the ground. The resonance frequency of the adjusting film bulk acoustic resonator (150) lies between the upper limit frequency of the transmission frequency pass band of the transmission band filter (110) and the lower limit frequency of the reception frequency pass band of the reception band filter (130). Therefore a transmission/reception switch such that the switch can be a monolithic element, the breakdown power is good, the size is small, and the cost is low is provided.

Thin-film micro-machine type resonator, thin-film micro- machine type resonator gyroscope, navigation system and automobile using the resonator gyroscope

Abstract: PROBLEM TO BE SOLVED: To provide a thin-film micro-machine type resonator which is improved in driving efficiency, a thin-film micro-machine type resonator gyroscope which is improved in detection sensitivity with respect to impressed angular velocities by improving its driving efficiency, and a navigation system and an automobile using the resonator gyroscope. SOLUTION: The thin-film micro-machine type resonator comprises a tuning fork having arms 2 and 3 and a base section 4 connecting the arms 2 and 3 to each other, first and second electrodes 10, 12, 11, 13 respectively and separately provided on the insides and outsides of center lines drawn on the principal surfaces 5 of the arms 2 and 3, and first and second piezoelectric thin films 14, 16, 15, and 17 respectively provided on the electrodes 10, 12, 11, and 13. The resonator also comprises third and fourth electrodes 18, 20, 19, and 21 respectively provided on the thin films 14, 16, 15, and 17. COPYRIGHT: (C)2003,JPO

A reduced-size silicon micromachined high-Q resonator at 5.7 GHz

Abstract: This paper depicts the progress toward a novel high-quality-factor miniaturized resonator operating in the 5.6-5.8-GHz range. The design of the resonator is based on a micromachined cavity loaded with a high dielectric-constant material. Energy is coupled into the cavity from input and output microstrip lines via slots. Quality factors up to 640 are demonstrated on silicon planar structures with a volume of 177 mm/sup 3/. Further size reduction yields a volume of 24.5 mm/sup 3/ and quality factors ranging from 152 to 197, while keeping the resonator integration ability. Bonding techniques and the dielectric loss of the loading material are proven to be the limiting factors in achieving higher quality factors.

Circularly polarized slot-coupled dielectric resonator antenna with a parasitic patch

Abstract: The circularly polarized slot-coupled cylindrical dielectric resonator antenna with a parasitic patch is investigated experimentally. The return loss, axial ratio, radiation pattern, and antenna gain of the antenna are studied and the effects of varying the parasitic patch are discussed.

Bandwidth enhancement of a monopole using dielectric resonator antenna loading

Abstract: A broadband monopole is investigated. The bandwidth enhancement is achieved by loading a monopole with a dielectric resonator antenna (DRA) operating in a TM 01δ mode to maintain a desirable omnidirectional radiation pattern. Preliminary results validate the design concept.

Reduced size capacitive defect EBG resonators

Abstract: The concept of a capacitive defect in a periodic lattice is examined. An eigenvalue analysis has been performed to determine the resonant frequency of a capacitive section that forms a defect in an otherwise periodic lattice of metallic vias. This concept presented herein addresses one of the major concerns in a defect mode resonator scheme: the overall size of the structure. Theoretically by loading the cavity with a capacitive load, a size reduction up to a full order of magnitude can be achieved depending on the height of the capacitive post. Furthermore the Q remains relatively the same even with a substantial size reduction. However as a practical issue, the sensitivity of the resonant frequency limits the achievable reduction for a given set of fabrication tolerances. The sensitivity of the resonator frequency and the resonant quality factor of a capacitive defect resonator has been the focus of this study. In the evanescent defect EBG resonator presented herein, the second order resonance is not an integer multiple of the dominant resonant frequency thus resulting in a very clean spectrum. As an example of an application for this EBG resonator, multiple capacitive defects in a metallo-dielectric EBG substrate have been coupled to form a reduced size multipole filter.