Showing papers on "Dielectric resonator antenna published in 1998"

Recent advances in dielectric-resonator antenna technology

Abstract: This paper features some of the advances in dielectric-resonator antenna technology at the Communications Research Centre. Several novel elements are presented that offer significant enhancements to parameters such as impedance bandwidth, circular-polarization bandwidth, gain, or coupling to various feed structures. Several linear and planar arrays are also presented, to illustrate the performance of dielectric-resonator antenna elements in the array environment.

Semiconductor micro-resonator device

Abstract: An optical, semiconductor micro-resonator device includes a microcavity resonator (12) and a pair of adjacent waveguides (14, 16). The microactivity resonator has a curved diameter of approximately 56000*lambda.lg/n.res or less where lambda.lg is the longest operating wavelength of light and n.res is the propagating refractive index. Light propagating in the first waveguide (14) with a wavelength on resonance with the microcavity resonator is coupled to the second waveguide (16) for output therefrom. Light propagating in the first waveguide (14) with a wavelength that is off resoance with the microcavity resonator continues to propagate in the first waveguide (14) for output therefrom.

Method and system for detecting material using piezoelectric resonators

Abstract: A method and system for detecting material bound on a surface of a piezoelectric resonator (20) introduces a signal of a constant frequency through the sensing resonator and detects a change in the insertion phase shift of the resonator (20) as a result of the binding of the material being detected on the surface of the resonator (20). Environmental effects on the measurement are effectively canceled by the use of a reference resonator driven by the same input signal (21). A multiple-port sensing device is provided which includes thin-film sensing and reference resonators monolithically formed on a substrate.

Moisture and density sensor

Abstract: A microwave resonator for connection to an instrument for measuring the density and/or moisture profile in the longitudinal direction of a sample, which microwave resonator has a through-hole (3) at right angles to its area extent, which through-hole (3) is bounded by metallic walls (4) extending in the longitudinal direction, distinguishes itself in that the interior (1) of the resonator is essentially flat, with a thickness which is considerably less than the lateral dimensions at right angles to it, and in that the resonator is filled with a dielectric.

Oven-heated crystal resonator and oscillator assembly

Abstract: A crystal resonator assembly is described wherein a piezo-electric resonator (14) is mounted over a heat conducting substrate (28) and one or more heat generating elements (40) are located on the substrate. The heating elements provide heat both by conduction and radiation and by virtue of the use of a heat conducting substrate enable a uniform and efficient heating of the crystal resonator to a desired oven temperature.

Dielectric combline resonators and filters

Abstract: The dielectric combline resonator combines the merits of the metallic combline and dielectric loaded resonator. By replacing the inner conductor of the conventional combline resonator by a high E, dielectric rod, higher unloaded Q can be expected. Resonant frequency, unloaded Q, and coupling coefficient of the resonator are obtained by a rigorous mode-matching method. An eight-pole elliptic-function dielectric combline resonator filter was designed and tested. Measured frequency responses verify the theory.

A vibrating structure gyroscope

Abstract: A vibrating structure gyroscope has a vibratory resonator having a substantially ring or hoop-like shape structure, an electromagnetic drive for causing the resonator to vibrate, a support structure including a plurality of flexible support beams for supporting the resonator whilst allowing it to vibrate and an electromagnetic sensor for sensing movement of the resonator. The support beams and resonator are made from silicon and the electromagnetic drive and sensor include metal tracks which extend externally along each support beam onto and along respective segments of an outer substantially planar surface of the ring-like resonator. The resonator is substantially planar and means is produced a magnetic field substantially perpendicular to the plane of the resonator.

Article comprising a micro-machined filter

Abstract: An article comprising a micro-machined filter advantageously comprises a micro-machined resonator, a drive circuit and a detection circuit, at least a portion of which are circuits are disposed on the resonator within a magnetic field. In operation, an input signal is delivered to the drive circuit. The resonator is excited to movement by the Lorentz force that is generated as signal current varies. Due to the resonator's movement, a voltage is induced in the detection circuit, which moves with the resonator. Using well-known micro-machining techniques, a resonator can be made that has mechanical resonance frequencies extending into the GHz regime. Under proper conditions, such resonances advantageously exhibit very high Q-values, so that the resonator shows a significant physical response (e.g., movement) over a very narrow range of excitation frequency. When the frequency of the input signal matches such a frequency (i.e., the resonant frequency), the device generates a voltage having such a frequency.

Planar resonator sensor for moisture measurements

Abstract: In the paper a model of microwave planar resonator sensor has been presented. The structure of resonator sensor is described. A dielectric material is placed above microstrip ring resonator. As a consequence, the parameters of resonator: resonance frequency, quality factor, and resonance transmission change in relation to the permittivity of the material. The first results of measurements are presented. The sensor may be used for nondestructive measurements of the moisture content of dielectric materials like grain or sand.

Annular slot-coupled dielectric resonator antenna

Abstract: An annular slot-coupled dielectric resonator antenna is investigated experimentally. As compared with the previous rectangular-slot version, the new configuration offers a much wider bandwidth of 18%. The return loss, radiation patterns, and antenna gain of the configuration have been measured and are discussed.

Low cost packaging for thin-film resonators and thin-film resonator-based filters

Abstract: An acoustic reflector (48) is applied over a thin-film piezoelectric resonator (41, 61) which is supported on a semiconductor or semiconductor-compatible substrate (42, 62) of a microelectronic device (40, 60), enabling an encapsulant (49) to be applied over the reflector-covered resonator without acoustically damping the resonator. In one embodiment, alternating high and low acoustic impedance layers (51, 53 . . . 55) of one-quarter wavelength thicknesses constructively reflect the resonating wavelength to make an encapsulant in the form of an inexpensive plastic molding compound appear as a "clamping" surface to a resonator (41) peripherally supported over an opening (43) on a silicon substrate (42). In another embodiment, an encapsulant- and reflector-covered resonator (61) is mechanically supported above a second reflector (68) which eliminates the need for peripheral support, making substrate (68) also appear as a clamping surface. The invention enables low cost plastic packaging of resonators and associated circuitry on a single monolithic structure. A radio frequency transceiver front-end application is given as an exemplary implementation.

Two-dimensional cylindrical dielectric resonator antenna array

Abstract: A square 2 × 2 subarray and infinite phased array of aperture-coupled cylindrical dielectric resonator antennas is investigated experimentally. The return loss, radiation pattern, and antenna gain are studied and compared with those of the single element antenna, and the waveguide simulator is used to measure the return loss of the element in an infinite array environment

Track-changing utilizing phase response of resonators

Abstract: A device and method of track changing an optical signal beam in response to the frequency selective phase characteristics of a resonator. The resonator is side-coupled to a single optical beam and only affects that beam's phase, without disturbing its amplitude to any significant degree. For all resonator and input beam configurations, the phase-shift at a resonant frequency is always π, thus the relative switching characteristics are similar regardless of the exact configuration. Track changing is accomplished through interferometry. The signal, after having interacted with the resonator, is made to interfere with a reference beam. The reference beam is created by dividing an input signal into two paths, one which interacts with the resonator, the other which serves as the reference. In an alternative embodiment, the device acts as a mode converter. The resonator converts an even system-mode to an odd system-mode (or vise versa). At the output of the device is an interference filter, or mode filter, which redirects the signal according to the phase response of the resonator.

Triple mode dielectric resonator hybrid reflection filters

Abstract: A new class of dielectric resonator filter is described. These devices use the triply degenerate TE/sub 11/spl delta// mode in a cubic dielectric resonator. A simple theory is used to show the similarity between this mode and the TE/sub 10/spl delta// mode in a cylindrical resonator. The cubic resonator is used in a hybrid reflection mode filter where the even and odd subnetworks of a bandpass filter are connected to two ports of a 3 dB quadrature hybrid. The transmission response through the other two ports is then the reflection coefficient of the bandpass filter. The design approach only requires the realisation of simple one port ladder networks and is ideal for realising complex filters using triple mode resonators. A design example is presented for a degree 6 elliptic function bandstop filter operating in the 850 MHz cellular radio band. A threefold size reduction is achieved when compared to single mode filters with similar electrical performance.

Resonators for accurate dielectric measurements in conducting liquids

Abstract: The compact, rugged, re-entrant radio-frequency resonator [A. R. H. Goodwin, J. B. Mehl, and M. R. Moldover, Rev Sci. Instrum. 67, 4294 (1996)] was modified for accurate measurements of the zero-frequency dielectric constant (relative electric permittivity) er of moderately conducting liquids such as impure water. The modified resonator has two modes with frequencies near 216/er MHz and 566/er MHz. The results for er at both frequencies were consistent within 0.0002er, verifying that the low-frequency limit had been attained with water samples with conductivities in the range 100–2500 μS/m. The results for water and for the insulating liquid cyclohexane were within 0.0005er of literature values. The present analysis is based on a simplified equivalent circuit that accounts for the loading of the resonator by the external instrumentation. This circuit can easily be generalized for a resonator with three or more modes. The present resonator has a thick gold plating on its interior surfaces. With the plating...

FDTD analysis of probe-fed cylindrical dielectric resonator antenna

Abstract: The finite-difference time-domain (FDTD) method is employed to analyze a probe-fed cylindrical dielectric resonator antenna. Numerical results for the input impedance and radiation patterns of the dielectric resonator (DR) antenna operating in HEM/sub 11/spl delta// mode are presented and compare favorably with measurements. The effects of various parameters on the characteristics of the DR antenna are studied. Fabrication imperfection effects and the cross-polarization characteristics of this type of DR antenna are also investigated for the first time.

Dielectric duplexer with different capacitive coupling between antenna pad and transmitting and receiving sections

Abstract: A compact and highly effective dielectric duplexer comprises a dielectric ceramic block and a plurality of resonators arranged in a direction in the dielectric ceramic block, a half of the resonators constituting a transmitting section T, the remaining half of the resonators constituting a receiving section R, wherein an antenna terminal pad is capacitively coupled to the innermost resonator of the transmitting section T and to the innermost resonator of the receiving section R located adjacent to the innermost resonator to eliminate the use of a wave-dividing resonator, whereby the dielectric ceramic block can be dimensionally reduced in the direction along which resonators are arranged and hence it is adapted to down-sizing. Additionally, the coupling capacitance Ct of the antenna terminal pad and the transmitting section T is made greater than the coupling capacitance Cr of the antenna terminal pad and the receiving section R, whereby a return loss is reduced in both the transmitting section T and the receiving section R to improve the signal transmitting performance and the signal receiving performance of the dielectric duplexer.

Multi-mode dielectric resonance devices, dielectric filter, composite dielectric filter, synthesizer, distributor, and communication equipment

Abstract: A dielectric resonance device comprising small resonators in a plurality of stages, and a multi-mode dielectric resonance device having a high Q0 value. A dielectric core of a nearly rectangular parallelopiped shape that resonates in a plurality of modes such as TM01 delta -x, -y, -z, and TE01 delta -x, -y, -z, is disposed in the central portion of a cavity of a nearly rectangular parallelopiped shape in order to utilize these resonance modes.

Surface acoustic wave filter utilizing a particularly placed spurious component of a parallel resonator

Abstract: A surface acoustic wave filter significantly improves attenuation in the stopband by using a spurious component to improve the filter characteristics. The filter includes a surface acoustic wave substrate and a series resonator having a resonant frequency and an antiresonant frequency. The series resonator is electrically disposed between an input terminal and an output terminal in series so as to define a series arm. The filter also includes at least one parallel resonator having a resonant frequency and an antiresonant frequency which is substantially identical to the resonant frequency of the series resonator. The at least one parallel resonator is electrically disposed between the series arm and a ground terminal so as to define a first parallel arm. The series arm and the parallel arm define a ladder circuit such that the surface acoustic wave filter has a predetermined pass band. The first parallel resonator has a spurious component at a frequency located between the resonant frequency of the first parallel resonator and a low end of the passband of the surface acoustic wave filter or at a frequency located between the antiresonant frequency of the series resonator and a high end of the passband of the surface acoustic wave filter.

Modified waveguide model (MWGM) for rectangular dielectric resonator antenna (DRA)

Abstract: Based on the concept of effective dimensions, a modification to the conventional waveguide model (CWGM), usually used to predict the resonant frequency of rectangular DRA, is introduced. Compared with the experimental results, it is found that this newly introduced MWGM yields more accurate results for the resonant frequency than the CWGM. Accuracy of the results is also checked by comparison with numerically calculated values using a TLM-based commercial software. It is also found that the MWGM not only yields accurate values, but also results in considerable computation time savings. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 158–160, 1998.

Amorphous magnetostrictive alloy and an electronic article surveillance system employing same

Abstract: A resonator for use in a marker in a magnetomechanical electronic article surveillance system is composed of an amorphous magnetostrictive alloy containing iron, cobalt, nickel, silicon and boron in quantities for giving the resonator a quality Q which is between about 100 and 600. The amorphous magnetostrictive alloy is annealed in a transverse magnetic field for giving it a B-H loop which is linear up to about 8 Oe and an anisotropy field strength of at least 10 Oe. The resonator is incorporated in a marker in combination with a bias element which produces a bias field, and when the resonator is excited to resonate by a signal emitted by the transmitter in the surveillance system, it produces a signal at a mechanical resonant frequency which can be detected by the receiver of the detection system. The receiver is operated so as to look for the signal from the resonator at the resonant frequency in a first detection window which begins at approximately 0.4 ms after excitation of the resonator, and in a second detection window which begins at approximately 6 ms after excitation of the resonator. Due to the resonator having a quality Q in the above range, the signal produced by the resonator in the first window has a high amplitude in the first detection window which is no more than 15 dB below its amplitude immediately after excitation, but drops to a level in the second detection window which is at least approximately 15 dB below its level in the first detection window. The signal from the resonator can thus be reliaby detected as well as distinguished from spurious signals.

Tunable and matchable resonator coil assembly for ion implanter linear accelerator

Abstract: A resonator circuit capable of resonating at a predetermined frequency is provided. The resonator circuit comprises a fixed position coil inductor ( 62 ) having a longitudinal axis ( 92 ) and a capacitor ( 88, 82 ) electrically connected in parallel with each other to form a resonator ( 60 ), so that respective first and second ends of the inductor and the capacitor are electrically coupled together at a high-voltage end ( 64 ) and a low-voltage end ( 66 ) of the resonator ( 60 ). A radio frequency (RF) input coupling ( 70 ) is coupled directly to the inductor ( 62 ) at the low-voltage end ( 66 ) of the resonator. A high-voltage electrode ( 72 ) is coupled to the high-voltage end ( 64 ) of the resonator. A first resonator tuning mechanism is provided for varying the inductance of the inductor, comprising a plunger ( 90 ) movable within the coil of the inductor ( 62 ) along the longitudinal axis ( 92 ). A second resonator tuning mechanism is provided for varying the capacitance of the capacitor ( 88, 82 ). The first tuning mechanism provides fine tuning of the resonator by means of varying the inductance of the inductor ( 62 ), and the second tuning mechanism provides coarse or initial tuning of the resonator by means of varying the capacitance of the capacitor ( 88, 82 ).

Surface emitting semiconductor laser and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To avoid deteriorating the element by a means such that at least a part has a protrudent resonator and opening at the top face of the resonator and an embedded metal layer of a specified melting point or less is formed to closely contact a top electrode continuously formed along the resonator and an insulation film surface. SOLUTION: A main heating source for the surface emitting semiconductor laser having a protrudent resonator structure is the Joule heat of the resistance of an n-type semiconductor multilayer reflection layer 106 or a contact resistance of a p-type contact layer 107 and top electrode 110. These heat sources exist mainly at a resonator protrusion 108. By embedding the resonator protrusion 108 in a good thermal-conductivity embedding layer 112, the embedding layer 112 acts as a heat sink to accelerate the heat radiation of the resonator protrusion 108, thereby lowering the temp. of the resonator and thus the deterioration of the element can be avoided. To closely imbed the resonator protrusion 108, the heat treating temp. is set so as not to exceed 400°C. COPYRIGHT: (C)1999,JPO

Four‐element planar arrays employing probe‐fed cylindrical dielectric resonator antennas

Abstract: Three four-element planar arrays, with the radiating elements being cylindrical dielectric resonator antennas excited by probes at the HE11δ mode, are reported. The first array produces broadside radiation, whereas the other two provide maximum radiation at elevation angles of ∼35–40°. The resonant frequency, radiation pattern, gain, unloaded Q-factor, and impedance bandwidth of each array configuration are reported, and the experimental results are compared with the theoretical values. Results indicated that the gains of the three configurations were greater than the gain of the single element by factors of 4, 3, and 2, respectively. For all configurations, the impedance bandwidth was increased by ∼30° with respect to that of the single antenna. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 18: 315–319, 1998.

High Q tunable LC resonator operating at cryogenic temperature

Abstract: We present a step-motor based cryogenic tuning device for a high Q electrical resonator The resonator can be tuned in the 145–175 Hz frequency range Tuning is achieved by moving a superconducting core inside the 3 H superconducting coil of the resonator The resonator intrinsic quality factor of 18×106 is found to be unaffected by the superconducting core and by the drive system The noise of the resonator has been measured to be thermal The device has been developed to improve sensitivity and bandwidth performance of cryogenic resonant gravitational wave detectors equipped with resonant capacitance transducers

Vibratory rotation sensor with multiplex electronics

Abstract: The invention is a vibratory rotation sensor comprising a resonator and a resonator housing and a method for controlling and reading out the sensor utilizing multiplex electronics. The resonator is a rotationally-symmetric thin-walled object that can be made to vibrate in a plurality of standing-wave modes. One or more electrodes are attached to a surface of the resonator and connect to a single output port The housing has a plurality of attached electrodes in close proximity to the resonator electrodes. The method for controlling and reading out the vibratory rotation sensor includes applying driving voltages to the housing electrodes and determining the parameters of the standing waves by performing operations on the resonator signal that emerges from the resonator output port. A driving voltage may include either an excitation voltage or a forcing voltage or both. An excitation voltage has essentially no effect on the resonator dynamics but carries information pertaining to the standing-wave parameters when it arrives at the resonator output port. A forcing voltage causes forces to be applied to the resonator and thereby affects the dynamics of the resonator and the standing-wave parameters. The driving voltages applied to the housing electrodes are brought together into a single resonator signal as a result of being transmitted through the housing-electrode-resonator-electrode capacitances to the resonator output port. In order to extract the standing-wave parameters, the excitation and forcing voltages are designed to be separable by appropriate operations performed on the resonator signal.

Resonant frequency and quality factors of a silver-coated /spl lambda//4 dielectric waveguide resonator

Abstract: In this paper, resonant frequency, radiation loss, conductor loss, and dielectric loss of a silver-coated /spl lambda//4 dielectric waveguide resonator are investigated. Leakage of the electromagnetic field from the open-end face of the resonator is the only source of radiation, which also affects the resonant frequency. New theoretical expressions are devised to calculate resonant frequency, conductor quality (Q) factor, dielectric Q factor, and radiation Q factor. Effective conductivity of the silver-coated resonator is estimated from experimental unloaded Q factor. The theoretical analysis is validated by the experimental result and the data obtained using the finite-difference time-domain (FDTD) technique. Finally, we have designed and fabricated a dual-mode bandpass filter using this resonator.