Showing papers on "Dielectric resonator antenna published in 1983"

The resonant cylindrical dielectric cavity antenna

Abstract: An experimental investigation of the radiation and circuit properties of a resonant cylindrical dielectric cavity antenna has been undertaken. The radiation patterns and input impedance have been measured for structures of various geometrical aspect ratios, dielectric constants, and sizes of coaxial feed probes. A simple theory utilizing the magnetic wall boundary condition is shown to correlate well with measured results for radiation patterns and resonant frequencies.

Rectangular dielectric resonator antenna

Abstract: An antenna which consists of a resonant rectangular parallelepiped dielectric on top of a ground plane is described. Calculated radiation patterns and measured impedances are presented, and the effects of feed probe length variations are discussed.

Double tuned, coupled microstrip antenna

Abstract: A first antenna for radiating a signal at a predetermined frequency employing at least one 1/4 wavelength microstrip resonator positioned below a metal 1/4 wavelength radiator. A circularly polarized antenna including a 1/2 wavelength radiator electromagnetically coupled to a 1/4 wavelength resonator is further disclosed.

Coupling Coefficient Between Microstrip Line and Dielectric Resonator

Abstract: A formula of the coupling coefficient between a dielectric resonator and a microstrip line is derived from an analysis of the transmission characteristics of the microstrip line coupled to the dielectric resonator. A practical method of calculation is developed using Fourier analysis. The calculated values show good agreement with the experimental values.

Hermetically sealed oscillator with dielectric resonator tuned through dielectric window by adjusting screw

Abstract: Microwave dielectric resonator apparatus which, for example, may be a microwave oscillator frequency stabilized by a dielectric resonator or may be a microwave filter whose critical frequency is determined by a dielectric resonator, has the dielectric resonator environmentally protected in a hermetic chamber. As the hermetic integrity of the chamber would be destroyed by having a tuning slug therein at the end of a screw threaded into a tapped hole through a chamber wall for rotation by a screwdriver outside the chamber, the tuning slug is instead located within a non-hermetic chamber at the end of a screw threaded into a tapped hole through a wall of the non-hermetic chamber serving also as an outer wall of a housing enclosing both chambers. The chambers have an interface which is transparent to microwave fields and proximate the dielectric resonator and tuning slug. The interface preserves the hermetic integrity of the hermetic chamber and transmits part of the microwave field developed by the dielectric resonator, when it resonates, to the non-hermetic chamber to be variously interfered with by the tuning slug as the slug is moved by rotation of the screw into different positional relationships of interference with the transmitted field part. As known per se, such interference alters the distribution and amount of microwave energy stored in the resonating dielectric resonator, and thereby alters the microwave frequency at which the dielectric resonator resonates. By using a puck of barium titanate as the dielectric resonator, a resonant frequency of 12 gigahertz is typically obtainable with a range of stable adjustment thereabout in the vicinity of 20 megahertz.

Optical resonators with Gaussian reflectivity mirrors: misalignment sensitivity.

Abstract: An analytical solution to the problem of the misaligned optical resonator with a Gaussian reflectivity mirror is presented. It is shown that the fundamental mode of such a resonator remains a Gaussian beam which propagates along a tilted axis in the misalignment plane. The exact analytical solution yields simple expressions that characterize the misalignment sensitivity of the resonator by giving the beam-steering angle and the loss variations.

Nonradiative dielectric waveguide circuit components

Abstract: The nonradiative dielectric waveguide (NRD-guide) is a newly proposed dielectric waveguide which can substantially suppress radiation at curved sections and discontinuities and is applicable to great advantage for millimeter wave integrated circuits. Basic circuit components such as transitions between a metal waveguide and an NRD-guide, matched terminations, a ring resonator and a bandpass filter were fabricated with polystyrene material and tested successfully at 50 GHz. Measurements showed that each component worked as expected without suffering from undesirable radiation and interferences at all.

Resonator pressure transducer

Abstract: A quartz resonator pressure transducer includes a generally disc-shaped resonator section, a housing surrounding the resonator section and joined to the perimeter thereof, with the walls of the housing extending in opposite directions generally normal to the plane of the resonator section. Selected portions of the sidewalls are made thinner than the remaining sidewall portions so that when the housing is immersed in a fluid, a non-uniform stress will be produced in the resonator section. The housing and resonator section are formed so that the frequency of vibration of the resonator section is substantially independent of temperature and relatively independent of temperature transients.

Dielectric coaxial resonator

Abstract: PURPOSE: To reduce the material cost and assembling cost and also to improve the assembling work performance and the reliability in use by forming a capacitor electrode on an open end face of a conductor so as to mount directly a resonator unit body to a printed board or the like. CONSTITUTION: A resonator A is a two-stage form resonator where resonator units 1a, 1b of the same specifications are coupled magnetically. In the 1st resonator unit 1a, a circular through-hole 3a is formed to the center of a rectangular parallelopiped block form dielectrid 2a made of a ceramic or the like, an inner conductor 4a is formed to the circumference of the hole and an outer conductor 5 is formed to the outer surface of the dielectric as film, an electrode 6 short-circuiting electrically the outer conductor 5 and the inner conductor 4a is formed to one end face of the dielectric 2a so as to form a short-circuit end face 7 and the other end face is set to an open end face 8 respectively and a capacitor electrode 9a is formed to the open end face 8. The capacitor electrode 9a is an electrode where a device connecting side electrode 11a of a convexed from having a connecting terminal in matching with one side of the open end face 8 and a projected electrode 12a connected electrically to the inner conductor 4 are arranged oppositely at a prescribed interval and a required coupling capacitance is ensured between both the electrodes 11a and 12a. COPYRIGHT: (C)1985,JPO&Japio

On the design of a re-entrant square cavity as resonator for low-frequency ESR spectroscopy

Abstract: The construction and the design equations of a microwave resonator which can be used as sample cavity in a low-frequency ESR spectrometer are described. The resonator, which has the form of a re-entrant square cavity, has a Q factor of the order of 1000 and a maximum filling factor of 0.25. The resonant frequency can be conveniently evaluated using a very simple equivalent circuit which can be adapted to any shape of resonator. Four prototypes have been built and a good match has been found between the experimental values of the resonant frequencies and the theoretical ones. This agreement has been found to be particularly good for low values of the gap thickness.

Miniaturized Coaxial Resonator Partially Loaded with High-Dielectric-Constant Microwave Ceramics

Abstract: A partially dielectric-filled stepped impedance resonator (PDSIR) is introduced as a class of a miniaturized coaxial resonator. The length of this resonator is less than that of a fully dielectric-filled quarter-wavelength resonator. The conditions for obtaining resonance with a high dielectric constant of epsilon/sub r/ =35 or 85, sensitivity analysis, and temperature drift of the resonant frequency, are described. The spurious response, in which the characteristics are better than for a conventional quarter-wavelength resonator, is also analyzed.

Novel Techniques for Electronic Tuning of Dielectric Resonators

Abstract: Two techniques for electronically tuning the TE01 mode resonant frequency of a dielectric resonator are presented and compared. A compact tunable dielectric resonator assembly is described which offers greater than .75% tuning range and an unloaded Q maintained at above 1000, features which are most desirable where low noise frequency agile sources are required.

On the design of a split ring resonator for ESR spectroscopy between 1 and 4 GHz

Abstract: The construction and the design equations of a resonator for low frequency ESR spectroscopy are described. The resonator consists of a thin wall split ring which can be designed for a particular frequency by careful choice of the ring inductance and the gap capacitance. The design equations have been obtained on the basis of a very simple equivalent circuit which takes into account the resonator parameters and the coupling of the resonator with the microwave bridge. Prototypes have been built for frequencies between 1 and 4 GHz but resonators for lower or higher frequencies can be easily constructed. At a frequency of 2.1 GHz, a power level of 10 mW and using an aqueous sample a sensitivity of 8*1011 spins/Gauss has been obtained. This sensitivity compares favourably with that of an X band spectrometer in the case of aqueous samples.

Dielectric resonator tuner and mechanical mounting system

Abstract: A combined mounting and tuning structure for a dielectric resonator comprised of a stack of a dielectric resonator body, a resilient body of dielectric material and an electrical tuning conductor. A fastening means preferably in the form of a dielectric screw threadedly engaged in a base wall of an enclosure and by turning the fastening means, the tuning conductor is brought closer to the resonator, and the resonant frequency of the resonator is thereby adjusted while also providing a clamping force on the stack so as to maintain its position relative to the base wall. The dielectric resonator tuner of the invention is shown in oscillator and filter circuit embodiments.

Frequency-adjustable coaxial dielectric resonator and filter using the same

Abstract: A coaxial dielectric resonator for VHF and/or UHF band comprising a generally cylindrical dielectric having inner surface and outer surface. The inner and outer surfaces of the dielectric are respectively covered by outer and inner conductors and these conductors are connected at one end of the dielectric. An adjusting screw for adjusting resonance frequency is provided at the other end of the dielectric which is covered by a lid while holding a gap between the adjusting screw and the lid. A microwave filter using a plurality of the coaxial dielectric resonator is further described.

Ring shaped dielectric resonator with adjustable tuning screw extending upwardly into ring opening

Abstract: A ring shaped dielectric resonator tuned by inserting a bolt from below the resonator into an opening of the resonator. The bolt causes the dielectric constant of the opening to change. The change in the dielectric constant changes the electric field which in turn changes the magnetic field of the resonator.

MIC Dual mode ring resonator filter

Abstract: An electromagnetic filter assembly comprises a transmission line electromagnetically coupled to a dual mode resonator having a means for differentially tuning the two modes. The filter may be incorporated in a microwave integrated circuit, and the tuning means may be a movable dielectric slab asymmetrically disposed on the resonator.

Scattering Matrix Description of Microwave Resonators

Abstract: In this paper an analysis of the scattering matrix coefficients (reflectance and transmittances) of the microwave resonators is presented. Two general cases of resonator couplings are considered. One of them is a multiport with one port terminated by the resonator, the other is a resonator coupled, in various ways, to a number of transmission lines. The effect of external circuits on the Q and resonant frequency of the resonator has also been examined. Fundamental parameters for the commonly used microwave resonator couplings are shown in Table L

Vibratory digital temperature sensor

Abstract: A temperature sensor is formed by mounting a force-sensitive resonator on a resilient or non-resilient base structure, preferably in an enclosure such that thermally induced expansions or contractions of the base structure apply a stress to the resonator. The resonant frequency of the resonator is measured to provide an indication of the temperature of the base structure and resonator.

Microwave oscillator with TM01δ dielectric resonator

Abstract: A microwave oscillator with TM01δ dielectric resonator is disclosed. The oscillator operates with a TM01δ mode as contrasted with prior art techniques of TE01δ mode. This provides for an improved tuning range in excess of 10% of the operating frequency.

Dielectric resonator and method for adjusting resonance frequency of dielectric resonator

Abstract: PURPOSE:To adjust easily and accurately a resonance frequency by providing an electrode for capacitance adjustment formed with many metallic pieces in mesh form to an open end side of a dielectric resonator so as to control the area of the electrode. CONSTITUTION:The electrode 35 for capacitance adjustment made of many metallic pieces divided minutely is provided to an upper face (open end side) 34 of the dielectric resonator 31 consisting of one dielectric and the electrode 35 is connected to a metallic rod (inner conductor) 36. In cutting the resonator into halves and viewing them from the X direction, a dielectric 53 is found between the electrode 52 and a side face 54, and when the electrode 52 and the side face 54 are approached together, the capacitance 55 formed by them is increased and the resonance frequency of the resonator is decreased. Thus, when B (1, 1) and B (1, n) are cut off from the metallic pieces divided minutely of the electrode, it is found that the resonance frequency is increased most. The resonance frequency is adjusted easily and accurately by controlling the area of the electrode in this way.

Polarisation-maintaining single-mode-fibre resonator

Abstract: A polarisation-maintaining fibre resonator has been set up. A finesse of 9 and a free spectral range (FSR) of 559 MHz are measured by feeding the resonator by a semiconductor laser.

An investigation on electromagnetic fields and properties of the loop-gap resonator, a lumped mode microwave resonant structure

Abstract: Loop-gap resonators are newly developed microwave resonant structures with a field configuration that is intermediate between lumped and distributed. Typical characteristic dimensions are of the order of 1/10 of the resonant wavelength, and typical Q's are of the order of 1600-2000 in the frequency range of 1-4 GHz. Data are presented for Q's and frequencies for a series of resonators of various dimensions and compared with theory. Various coupling and frequency tuning techniques are discussed, and results of experiments are reported. Results of preliminary application of the stictire in microwave filters and oscillators are presented. Loop-gap resonators provide a useful design alternative, it is concluded, to dielectric and surface acoustic-wave resonators at low microwave frequencies.

Injection-locked unstable laser

Abstract: A laser system for producing a laser beam in an unstable resonator whose spatial and temporal characteristics conform with those of a laser beam from a stable resonator The laser system includes three reflectors, an optical switch and a laser gain medium positioned within an optical propagation path extending between the optical switch and the third reflector The optical switch selectably exposes either the first or the second reflector to the aforesaid propagation path, the first and second reflectors being designed to form, in combination with the third reflector, a stable and an unstable resonator, respectively In operation, the optical switch initially is set so as to include the first reflector in the laser resonator, thereby forming a stable resonator which produces a beam of laser light A short time thereafter, the optical switch changes states so as to substitute the second reflector for the first, thereby forming an unstable resonator The light from the stable resonator serves as "seed radiation" for the unstable resonator, so that the unstable resonator produces a light beam having the same spatial and temporal characteristics as the light from the stable resonator The system permits the use of a single laser gain medium for both resonators, and it overcomes the need for holes or other surface discontinuities in the resonator reflectors which can degrade the quality of the laser's output beam

Computation of the resonant frequency of a dielectric resonator by a differential method

Abstract: A differential method to compute, with high accuracy, the resonant frequency of a dielectric body with an axis of revolution and placed between two conducting plates is described. The propagation equations, projected on a Fourier basis, are integrated by the Adams-Moulton predictor-corrector algorithm and matched to the modified Bessel expansion of the field. Numerical results obtained for the cylinder shape are compared with those obtained by a modal theory, exhibiting an accuracy better than 10−4. Results for a dielectric sphere are given as another application.

Surface acoustic wave mode conversion resonator

Abstract: It is well known that a ZnO‐on‐Si structure supports two distinct surface waves, called the Rayleigh and the Sezawa modes, if the ZnO layer is sufficiently thick. Herein we report a unique surface wave resonator that operates by efficiently converting between the two modes at the resonant frequency. The mode conversion resonator promises enhanced out‐of‐band signal rejection since input and output coupling is effected through different modes.

'Tunnel' Locking Stimulated Raman Radiation Components in an Optical Resonator

Abstract: Stimulated Raman radiation is considered in an optical resonator excited by an external light beam. It is assumed that the resonator is filled with a dispersive (condensed) medium for a length of the medium (along the resonator axis) close to several ‘tunnel’ lengths. A Raman-active medium is assumed to fill part of the resonator length along the resonator axis. Numerical calculations are presented of tunnel locking stimulated Raman radiation components. The shape of light pulses is calculated, and the band of locking Stokes components is derived. The feasibility of generating a light pulse of duration 3 × 10-14 −4 × 10-15 s in a frequency region close to the point ∂2 n eff / ∂ω2 = 0, located usually in the infrared spectral region (n eff is the effective refractive index of the substance inside the resonator) is discussed. Also discussed is the feasibility of correcting the refractive index dispersion and generating femtosecond light pulses in the visible spectral region.

Microwave oscillator and single balanced mixer for satellite television receiver

Abstract: A microwave oscillator and a combination microwave oscillator/single balanced mixer for a satellite television receiver includes a cylindrical dielectric resonator located on one side of a ground plane formed by a conductive foil on a substrate with microstrip transmission lines formed by foil patterns on the opposite side of said substrate. A gallium arsenide FET is disposed in a hole through said substrate with its source electrode connected to the ground plane and its drain and gate electrodes coupled to first and second transmission line strips, portions of which are following the contours of said dielectric resonator. Two sets of coupling slots are formed in the ground plane for permitting magnetic coupling between the dielectric resonator and the opposite transmission line strips. In one embodiment an additional coupling slot in the ground plane couples the dielectric resonator to an output transmission line strip. In another embodiment a dual diode package is disposed in a square hole in the substrate and ground plane with the common junction of the two diodes being coupled to a third transmission line strip and the opposite ends of the series connected diodes coupled to the ground plane. Coupled magnetic energy from the resonator creates a potential difference across the ground plane at the opposite sides of the square hole thus generating a local oscillator signal across the series connected diodes. The third transmission line strip serves as a coupling for both an RF signal input to and an IF signal output from, the mixer.

A Proposal of a New Dielectric Resonator Construction for MIC's

Abstract: A compact and high-temperature-stable dielectric resonator having no shielding metal walls nor a conventional frequency tuning screw is described. This resonator consists of a high epsilon/sub r/ dielectric resonator element mounted on a low-loss dielectric mount, a dielectric disk with thin metal film fixed on the resonator element, and a microstrip line substrate on which to mount the constituents. The resonant frequency tuning is made by trimming the metal film on the disk. The TE/sub 01delta/ -mode resonant frequencies are analyzed through dielectric waveguide model application. Less than 1-percent analytical error is presented in comparison with the experimental data for a practical resonator. The frequency tuning limit by metal film trimming is about 7 percent. The unfoaded Q value of 2700 at 8.8 GHz and a 4.4-ppm/deg frequency temperature coefficient are obtained.