Showing papers on "Dielectric resonator antenna published in 1989"

Broadband stacked dielectric resonator antennas

Abstract: The input impedance of stacked cylindrical dielectric resonator antennas is investigated experimentally. The dielectric resonators are made of different materials. The bandwidth of 25% has been observed for a standing wave ratio better than 2.

Microwave plasma treating apparatus

Abstract: A microwave plasma treating apparatus comprising a vacuum vessel, a device for introducing a microwave to the inside of the vacuum vessel by way of a microwave transmission circuit, a device for supplying a starting gas to the inside of the vacuum vessel, a device for evacuating the inside of the vacuum vessel, and a specimen holder for maintaining a specimen substrate to the inside of the vacuum vessel, wherein a cavity resonator integrated with two matching circuits is disposed in the microwave transmission circuit and a magnetic field generator is disposed to the outside of the cavity resonator, and having the following main features: (a) matching facilitated by a plunger for adjusting the axial length of the cavity resonator and cylindrical sling type irises, E-H tuner or three-stub tuner disposed at the portion of the cylindrical cavity resonator where the microwave is introduced, (b) a bell jar disposed within the cavity resonator to excite TM mode and (c) a magnetic field generator disposed to the outside of the cavity resonator to prepare a region of a great magnetic flux density in the discharging space at the inside of the cavity resonator.

High Q coplanar transmission line resonator of YBa2Cu3O7−x on MgO

Abstract: We present the first coplanar waveguide transmission line resonator patterned from a perovskite high Tc superconducting film at 9 GHz. At 77 K the unloaded quality factor Q0 of the resonator patterned from a YBa2Cu3O7−x film on a MgO substrate is 1300, that is, 14 times higher than that of the copper resonator and 17 times higher than that of the gold resonator at the same temperature. At 4.2 K a Q0 factor of 3300 was measured for the YBa2Cu3O7−x /MgO resonator. Simple calculations of the quality factor show that values of 10 000 at 77 K should be possible using better substrates, films, and etching techniques. This resonator could form the basic structure of more complex microwave filter systems operating at liquid‐nitrogen temperatures.

High-power waveguide laser

Abstract: In order to improve an electrically excited, diffusion-cooled highpower laser comprising two wall surfaces slightly spaced from one another and forming an optical waveguide, the width of the wall surfaces being a multiple of the space between them and the surfaces enclosing between them a flow-free discharge chamber, and also comprising an optical resonator having resonator mirrors disposed at both ends of said waveguide, such that his results in a laser beam which can be well focused, it is suggested that the resonator be an optically unstable resonator including a beam path extending lengthwise of a resonator axis and having an expansion transverse to the resonator axis extending as far as at least one exiting laser beam and that the transverse expansion extend transversely to a longitudinal direction of the waveguide and approximately parallel to the wall surfaces.

Half-split dielectric resonator placed on metallic plane for antenna applications

Abstract: A practical dielectric resonator antenna structure has been proposed for use at microwave and millimetre-wave frequencies. The radiator can be designed to have a low radiation Q-factor resulting in a relatively wider bandwidth of operation. The scheme used for feeding the antenna shields the feeding arrangement and the associated circuitry from the radiation zone.

Internally mounted broadband antenna

Abstract: An internally mounted broadband antenna (Figure 5) utilizing two resonators (503, 501 and 505, 501) and a reactive ground feed is disclosed. A nonconductive notch (511) separates a conductive surface (501) into two portions which are coupled to a respective one of each resonator. Each resonator (503, 501 and 505, 501) is a microstrip conductor forming a transmission line with its respective conductive surface portion. Coupling to the antenna is accomplished by connection (519 and 521) across the notch (511).

Optical resonator structures

Abstract: At least one optical resonator having a selected optical processing property is formed upon a substrate. Various property resonators may be stacked upon one another so as to share a common optical axis. A resonator typically has a pair of multilayer dielectric or semiconductor mirrors formed on opposite ends of an optical cavity with the mirrors formed in a plane parallel to the substrate surface. Temperature and mechanical stability superior to current technology is thus achievable in the structure. Additional combinations of mirrors, cavities and gratings may be formed in conjunction with the resonator.

Fiber-coupled short Fabry-Perot resonators

Abstract: An air-gap Fabry-Perot resonator with plane mirrors between closely spaced fiber ends may yield low throughput because of the poor match between the modes of typical single-mode fibers and the resonant mode in the air-gap cavity. The throughput can be improved by confining the resonant mode by a hollow dielectric tube placed inside the resonator. Short fiber-coupled Fabry-Perot resonators with and without an inserted hollow dielectric waveguide and expressions for their transmission losses are derived. It is shown that the throughput of both types of resonator can be improved significantly by using fiber with large mode size to couple to the resonator. The special fiber is then spliced to a conventional single-mode fiber. It is concluded that the resonator with an inserted hollow dielectric waveguide offers increased throughput for resonators with high finesse. >

Measurement and analysis of a microwave oscillator stabilized by a sapphire dielectric ring resonator for ultra-low noise

Abstract: Phase noise measurements are presented for a microwave oscillator whose frequency is stabilized by a whispering-gallery mode sapphire ring resonator with Q of 2*10/sup 5/. Isolation of RF fields by the special nature of the electromagnetic mode allows the very low loss of the sapphire itself to be realized. Several mode families have been identified with fairly good agreement with calculated frequency predictions. Waveguide coupling parameters have been characterized for the principal (lowest frequency) mode family, for n=5 to n=10 full waves around the perimeter. Based on the measurements and on the performance of commercially available phase detectors, the performance for a cooled resonator operating at 77 K with a Q of 3*10/sup 7/ is projected to be -85 dB/Hz at an offset of 1 Hz. This value is 30 dB below that of the best X-band source presently available, a frequency-multiplied quartz crystal oscillator. >

High-Q helical resonator for oscillators and filters in mobile communications systems

Abstract: A high-Q helical resonator is described which is directly coupled and resonant for lengths of approximately λ/2. This resonator is extremely easy to fabricate, and is used to demonstrate high-Q filtering and low-noise oscillator operation as the resonator in state-of-the-art L-band oscillators.

Dielectric stepped impedance resonator

Abstract: A coaxial dielectric resonator for use at high frequency. The outer or inner peripheral surface of a tubular dielectric member is stepped so as to provide a greater suppression of spurious resonance. The dielectric member has a prism-shaped outer configuration so as to provide a high Q value, as well as improved space factor.

Filter having a dielectric resonator

Abstract: A filter having a dielectric resonator, the filter comprising at least one cylindrical cavity (10) containing a cylindrical dielectric resonator (11) whose axis of symmetry (Δ) is colinear with the axis of said cavity (10), and the resonator being held in a longitudinally asymmetrical position inside said cavity (10) by a mandrel system which clamps around the cylindrical portion thereof and which includes at least one spoke for fixing it to said cavity while leaving play relative to said cavity.

Piezo-electrically tuned optical resonator and laser using same

Abstract: An optical resonator, preferably of a solid state laser (11) is tuned by one or more sheets (41, 52) of piezo-electric material bonded to one or more tuning facets of an optically transparent solid state member portion (12) of the resonator. A tuning voltage applied across the piezo-electric sheet (41, 52) tends to change the area of the bonded interface of the sheet (41, 52) to generate a set of tuning forces predominantly in the plane of the surface of the tuning facet. These tuning forces are transmitted through the tuning facet into the solid state portion of the optical resonator to produce a change in its refractive index and dimensional change which tunes the frequency of the optical resonator and the laser using same, if any. In a preferred embodiment, the piezo-electrically tuned optical resonator is an optically pumped ring resonator made of a lasant material such as Nd:YAG for tuning the output frequency of the ring laser (11).

Focal plane array antenna

Abstract: A microstrip focal plane array antenna is disclosed which includes a planar dielectric board 18 having a first surface 22 and second surface 28. A second radiating element 30 is located on the second surface 28 of the dielectric board 18 and a first radiating element 12 is located on the first surface 22 of the dielectric board 18. Energy is coupled to the first radiating element 12 from the second radiating element 30 and is reradiated by the first radiating element 12. In a specific embodiment, the second radiating element 30 is a resonator 30 at one end of a coplanar waveguide, 24, having longitudinal and traverse axes, 32 and 34 respectively. The first radiating element 12 is a microstrip patch 12 of conductive material, having longitudinal and traverse axes, 14 and 16 respectively. The microstrip patch 12 is aligned over the resonator 30 such that electromagnetic energy from the resonator 30 is reradiated as linearly polarized energy by the microstrip patch 12. In an alternative embodiment, the microstrip patch 12 is aligned relative to the resonator 30 such that the longitudinal axis 32 of the microstrip patch 12 is at an angle of 45 degrees with respect to the longitudinal axis 32 of the resonator 30. This orientation, is effective to cause the patch 12 to radiate circularly polarized energy.

Microwave oscillator in which the dielectric resonator is hermetically sealed

Abstract: A microwave oscillator which has a dielectric resonator which has properties which are dependent on the atmospheric humidity and which should be sealed in a hermetically air tight container to eliminate variations in its characteristics. The dielectric resonator is mounted in a hermetically sealed air tight cavity inside a metal housing in which the electrical circuit is mounted and is arranged at a position relative to coupling elements on a film printed circuit board which has a metallized surface on one side thereof.

Unloaded Q's of axially asymmetric modes of dielectric resonators

Abstract: A method for calculating the unloaded Q of hybrid modes in a dielectric loaded resonator is described. The method is applied to a 33 GHz resonator on a GaAs substrate. The contribution of the losses in each of the resonator's elements is computed separately. It is shown that the hybrid modes can have substantially higher Q's than the TE modes. This result is particularly significant for millimeter waves. >

X-band monolithic tunable resonator/filter

Abstract: The experimental results of a GaAs MM1C varactor-tuned resonator are reported. Planar Schottky diodes are used in punch-through mode to allow large voltage swing operation. The resonator can be tuned over the frequency range 8.6– 9.75 GHz with ±0.2dB insertion loss flatness. It could find applications in oscillators and filters in radar systems.

Combiner arrangement in a radio base station

Abstract: A combiner arrangement in a radio base station including a number of waveguide cavity resonators operating as channel filters in known manner. According to the invention, each resonator is divided into two substantially equal cavity resonsator parts. One base station transmitter is connected to one of the resonator parts and another transmitter is connected to the other resonator part. The decoupling of a resonator consists of two clamp-like elements situated in the center of the resonator. The coaxial connection to the antenna consists of coaxial pieces between the resonators and all the resonators are connected in series to the antenna.

Monolithic quartz resonator accelerometer

Abstract: A monolithic quartz resonator accelerometer including a monolithic quartz sensing structure with a frame, a proof mass support structure within the frame, and a resonator structure interconnecting the frame and the support structure. Further included are a proof mass fixed to the support structure, and electrodes on the resonator structure for driving the resonator at a vibration frequency which varies as a function of the acceleration of the proof mass.

Waveguide laser system

Abstract: In order to improve an electrically excited, diffusion-cooled laser system comprising two wall surfaces slightly spaced from one another and forming an optical waveguide, the width of the wall surfaces being a multiple of the space between them and the surfaces enclosing between them a flow-free discharge chamber, and also comprising an optically unstable resonator having a resonator beam path travelling through at least part of the discharge chamber and extending lengthwise of a resonator axis as well as having an expansion transverse to the resonator axis extending as far as at least one laser beam exiting from the resonator, this transverse expansion extending transversely to a longitudinal direction of said waveguide and approximately parallel to said wall surfaces, such that the waveguide can be constructed with as large a surface area as possible without losing the beam quality of the beam exiting the waveguide, it is suggested that the resonator be followed by a laser amplifier, the amplifier beam path thereof travelling through an additional part of said discharge chamber.

Band-stop filter

Abstract: A band-stop filter comprises a plurality of resonator units each comprised of an end-shorted coaxial resonator and a variable condenser connected in series therewith, a printed circuit board combining said resonator units in a multistage having thru-holes adjacent a bushing which isolates the inner conductor of the end-shorted coaxial resonator from the printed circuit board. A thru-hole conductor is provided in the thru-hole, and an adjusting screw having a radius is a little larger than the thru-hole. The adjusting screw can have both the proper torque and the electrical connection. The inner conductor surface of the resonator operates electrically as a stator and the adjusting screw operates as a rotor.

4GHz Band Band-Pass Filter using an Orthogonal Array Coupling TM110 Dual Mode Dielectric Resonator

Abstract: A novel TM110 dual mode resonator using a monoblock ceramic was developed. The coupling principle of the resonator is explained by even and odd mode, and the design procedure is expressed. The trial 4GHz band band-pass filter is 12×12×30mm in the size, and shows 0.2dB in the insertion loss for the bandwidth of 500MHz and 0.35MHz in the temperature stability.

Three dimensional finite element method applied to dielectric resonator devices

Abstract: The three-dimensional finite-element method is used to evaluate the electromagnetic and electrical parameters of a TE/sub 01 delta / cylindrical dielectric resonator (DR) housed in a parallelepiped metallic enclosure. The case of free oscillation is investigated. Numerical results concerning resonant frequencies, field vectors, and coefficients of coupling between two adjacent DRs are presented. >

A tunable, temperature compensated hybrid mode dielectric resonator

Abstract: A thermal and electromagnetic model of a tunable hybrid mode dielectric double resonator is introduced and analyzed by the mode-matching technique. The temperature sensitivity of the structure is shown as a function of the spacing between the double resonators as well as the other resonator parameters. A simple optimization procedure is described, that enables the design of the resonator to have both wide tunability range and good thermal stability of its resonant frequency. The choice of the optimum parameters is based on parametric analysis, which reveals depicts all the relevant sensitivities to the designer. Experimental verification of the analytical result has been verified experimentally. >

Investigations on EM field coupling in dielectric resonator

Abstract: A structure consisting of a dielectric resonator (DR) placed on a substrate with a spacer in between is considered. The axisymmetric mode of coupling is considered. The theoretical expressions for the resonance fields are derived. The coefficient of coupling between the DR and the microstrip line is numerically evaluated for the limiting case where the height of the spacer goes to zero and with the assumption that the fields in the free space region outside the body of the DR and at the top of the substrate is negligibly small. The numerical results show excellent agreement with the experimental results. The effects of the substrate thickness on the coupling coefficient are also examined. >

Monolithic dielectric filters in integrated waveguide technology

Abstract: We propose here a method to design monolithic dielectric filters (MDF) for achieving new levels of performance. The filter consists of a high-permittivity dielectric slab placed in a waveguide below cutoff loaded with low-permittivity dielectric slabs. These filters are miniature, highly selective, with low losses and small level parasitic resonances. A new approach is based on the equivalent circuits used to model the waveguide dielectric resonator of the monolithic filter. This model shows how the resonance frequency and coupling coefficient can be applied to synthesize a prescribed passband having Chebyshev or maximally flat characteristics. Experimental results are presented in S- and X-band showing good agreement with the theory.

Microwave channelizer based on coupled YIG resonators

Abstract: A coupled YIG resonator device for filtering a wide band microwave signal to provide a comparatively narrow output passband. The device has an enhanced bandwidth and improved out-of-band rejection relative to a single resonator configuration. The coupled resonator device includes a plurality of YIG films sharing a common non-magnetic substrate arranged in a plane and having a gap separating adjacent films. A dielectric layer has a first surface in contact with the YIG films and a second surface where a metallic ground plane is deposited. A magnetic biasing field is applied to the plurality of YIG films such that each forms a resonator having a resonance frequency. Adjacent resonators are magnetically coupled to each other by rf linkage across the gap therebetween. The magnetic coupling causes the respective resonance frequencies of the respective resonators to move apart relative to respective resonance frequencies occurring when no coupling is present, thereby enhancing the bandwidth and improving the out-of-hand rejection of the coupled resonator circuit. The center frequency of respective resonator circuits may be tuned by prescribing differing dimensions of the respective resonator circuits and applying a uniform magnetic biasing field. A microwave channelizer is comprised of a plurality of the aforementioned coupled YIG resonators integrated into one device. The channelizer separates microwave signals of different frequencies into individual output channels.

Some applications of microwave ceramic ring resonator in laboratory measurements

Abstract: We discussed application of a pillbox and open ring short circuited dielectric resonators. A confining of the magnetic field of TE011 mode in the empty region of ring resonator enabled us to employ the resonator as EPR cavity. Experimental results are shown.

Low noise microwave signal generation: resonator/oscillator comparisons

Abstract: The author compares existing and projected microwave signal spectral performance obtainable using various types of acoustic and non-acoustic high-Q resonators. Included is a discussion of recent progress in resonator technology such as improvements in conventional dielectric resonator and quartz crystal resonator performance, development of composite UHF resonators such as the high-overtone bulk acoustic resonator (HBAR) exhibiting tenfold increase in Q and decrease in vibration and sensitivity (compared to quartz), and superconducting cavity-type resonators exhibiting ultrahigh Q directly at microwave frequency. It is concluded that the generation of low-noise microwave signals depends, to a large extent, on resonator performance parameters including Q, short-term frequency stability, drive level, operating frequency, and are quite process-variable and consideration of device yield is important. Selection of optimum resonator technology (or multiple technologies) must be tailored to specific signal spectral performance requirements. >