Showing papers on "Dielectric resonator antenna published in 1981"

Dielectric loaded horn antennas having improved radiation characteristics

Abstract: An H-plane sectoral horn antenna is loaded with low-loss dielectric insertsn alternative embodiments so as to reduce beamwidth, increase axial gain and to achieve non-mechanical beam scanning. In one embodiment, the antenna is transversely loaded with a multi-layer dielectric array containing an air gap of critical thickness between four dielectric strips. In another embodiment, the antenna is longitudinally and symmetrically loaded with wedge-shaped dielectric strips separated by a critical air gap between the dielectric and antenna walls.

Generalized dielectric resonator filter

Abstract: A generalized dielectric resonator filter is disclosed for the realization of the most general transfer function characteristics of band-pass filters using cylindrical dielectric resonator discs in a microstrip transmission line configuration The dielectric resonator filter of the invention has electrical properties comparable to conventional waveguide filters, but has a much smaller volume and mass, and is thus very attractive for use in the construction of input multiplexers of communications satellite transponders

Miniature GT-cut quartz resonator

Abstract: The GT-cut quartz resonator resonated by two longitudinal modes and provided with the masses for frequency-temperature characteristics adjustment and frequency adjustment. The frequency-temperature characteristics and the frequency of the GT-cut quartz resonator are adjusted by eliminating the masses. Consequently, the quartz resonator adjusted to the normal frequency and having the excellent frequency-temperature characteristics is attained. Further the GT-cut quartz resonator of small and thin size is attained by making the resonant portion and the supporting portions in one piece by photolithographic technique.

Dielectric resonator and filter with dielectric resonator

Abstract: A dielectric resonator has a sector shape, and a filter has a signal source for emitting signal to be filtered, signal receiver for receiving the filtered signal and a path defined between the signal source and the signal receiver. At least one sector shaped dielectric resonator is disposed in the path.

Apparatus for atomizing liquids

Abstract: Apparatus for atomizing liquids which includes an ultrasonic excitation system, a bending resonator which oscillates at ultrasonic frequencies, and a device for the delivery of liquid into the velocity nodal region of the bending resonator. The bending resonator has at least one surface which is inclined with respect to the axis of the excitation system. The bending resonator can be in the form of an elongated narrow strip having a plurality of parallel nodal lines. The length of the excitation system is approximately (2n+1) λ/4, wherein n is 0 or an integer.

Millimeter-wave absorption measurements in low-loss dielectrics using an untuned cavity resonator

Abstract: Millimeter wave absorption measurements are usually complicated by scattering from the sample and by standing waves resulting from internal reflections. These problems can be largely overcome by using an untuned cavity resonator. The dielectric properties of the sample are determined from a measurement of the change in cavity Q produced by introduction of the sample into the cavity. For lamellar samples, Maxwell's equations can be used to find an explicit relationship between the change in cavity Q and the samples complex refractive index. Several measuring techniques based on the use of lamellar samples are presented, and their characteristics are illustrated both analytically and by laboratory measurements at 70 GHz on PTFE, polyethylene and plexiglas.

Ultra-high frequency filter with a dielectric resonator tunable in a large band width

Abstract: A dielectric resonator ultra-high frequency filter tunable in a large band width in which each dielectric resonator is constituted by a dielectric component with a high dielectric constant, which is fixed relative to an enclosure and a component made from the same dielectric material which is movable relative to the first component, in such a way that the distance d between facing surfaces of these two dielectric components varies, leading to a variation in the tuning frequency of the filter by modifying the coupling conditions.

Unstable-stable resonators with toroidal mirrors.

Abstract: A resonator with toroidal mirrors is described. This resonator behaves like an off-axis unstable confocal resonator in one transverse dimension and like an on-axis concave–convex stable resonator in the other orthogonal dimension. Some experimental results are reported for a fast flow high power cw-CO2 laser whose transverse cross section is restricted in the stable-resonator direction. These cavities allow an output laser beam with a fully illuminated cross section which is well suited for focusing. Moreover, the fraction of the available laser power which may be concentrated in the central lobe of the focal plane intensity distribution is 2.5–4.5 times higher than other unstable resonators with similarly restricted modal volumes. Finally the alignment requirements are examined.

Unloaded quality factor measurement for MIC dielectric resonator applications

Abstract: The unloaded quality factor of a dielectric resonator, in the MIC environment, and magnetically coupled to a terminated microstrip line, is estimated by using a network analyser. It is sufficient to compute the relative bandwidth of the interception between the reflection coefficient locus and the R − 1 = ±jX arcs.

Vibration type density meter

Abstract: A vibration type density meter includes a mechanical oscillator or resonator having a resonance frequency variable with the density of a specimen fluid around the oscillator. The resonator is of a cylindrical configuration with flanges at the ends thereof, at least one of the ends being open for introducing specimen fluid into the resonator. The meter also includes means for exciting the resonator, means for detecting oscillations of the cylindrical resonator, a cover coupled to the flanges of the resonator in surrounding relation to the latter, and circuit means for processing a frequency signal from the oscillation detecting means, and by arithmetic operations derive and display the density of the specimen fluid being measured.

Circuit for linearizing frequency modulated oscillators on microstrip

Abstract: In a microstrip frequency modulated oscillator, the linearity of the modulating circuit incorporating a varactor diode is adjusted by using a microstrip transmission line as a secondary resonator in conjuction with a variable reactor. The varactor is connected to one end of this resonator which end is also connected to the main resonator of the microstrip oscillator. The variable reactor is connected between the other end of the secondary resonator and ground.

Correction to "Cylindrical Dielectric Resonators and Their Applications in TEM Line Microwave Circuits"

Abstract: A cylindrical sample of low-loss, high- ¿r dielectric placed between two parallel conducting plates perpendicular to the sample axis forms microwave resonator. A simple approximate method for predicting the resonant frequencies of the TE modes of this structure is developed. The method becomes exact for the particular case of this structure, which is known as dielectric post resonator. The accuracy of the method is demonstrated experimentally and by comparison with previously published data (including a structure typical for MIC). The following examples of dielectric resonator - TEM-line microwave circuits are presented: reaction and retlection type cavities, band-reject and band-pass filters.

Resonant Frequency Stability of the Dielectric Resonator on a Dielectric Substrate

Abstract: A simple approximate method for predicting the resonant frequencies of TE modes of dielectric resonators is developed. By using this method, an analytical expression is derived for the resonant frequency stability of the dielectric resonator on a dielectric substrate, and the effect of the substrate on the stability is studied. The result is useful when the high-frequency stability is required.

Digital temperature sensor

Abstract: A temperature sensor (70) is formed by mounting a force-sensitive resonator on a base structure (76) such that thermally induced expansions or contractions of the base structure (76) 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 (76).

Microstrip bandstop filter using a dielectric resonator

Abstract: The paper presents a new analysis accurately predicting the external quality factor and scattering matrix parameters Sij of the TE01p cylindrical resonator mode, coupled with a microstrip line for arbitrary locations of the resonator and the line. The results obtained are used to ralise a Cheby?shev bandstop filter. Experimental and theoretical results are also included.

Temperature compensated piezoelectric ceramic resonator unit

Abstract: A thickness mode piezoelectric ceramic resonator is connected in series with a ceramic capacitor to form a piezoelectric ceramic resonator unit. When the ceramic capacitor has a capacitance Ca and the resonator is associated with a damped capacitor having a capacitance Co, these capacitances are related to each other by a relationship, Co≦Ca≦30 Co.

Atomic or molecular beam frequency standard with optical pumping and open resonator

Abstract: The apparatus comprises a source capable of producing an atomic (molecular) beam and at least one electromagnetic resonator of the open type through which the atoms (molecules) pass. Optical pumping means excite the atoms (molecules) of the beam into a selected energy level before the beam passes through the resonator. An electromagnetic field generator is connected to the resonator for generating inside said resonator a spatial distribution of electromagnetic field at a frequency corresponding to the difference between the energies associated to said first level or energetic state and a second level or energetic state of the atoms (molecules) in the beam. Detection means provide an electric signal indicative of the number of atoms (molecules) which inside the resonator undergo a transition to the above mentioned second level or energetic state. Said electric signal is used to control the frequency of said generator, in such a way as to maximize the number of atoms (molecules) which undergo a transition when they pass through said resonator.

TM/sub 01p/ Tubular and Cylindrical Dielectric Resonator Mode

Abstract: The electric dipole resonance of a cylindrical and a tubular dielectric resonator is investigated. Data are given about the resonant frequencies and the structure of the field surrounding the resonator. The data agree well with experimental results.

Microstrip transistor oscillator with dielectric resonator stabilization

Abstract: A device using a dielectric resonator with a very low temperature coefficient in a very high frequency transistor oscillator (3 to 10 GHz) so as to benefit both from the very high power available and the maximum frequency stabilization due to the resonator In the case of a FET, the gate is connected to one end of a line coupled to a dielectric resonator at a point along the line situated at a quarter wavelength from the other end of the line, which in turn is connected through a discrete resistor to a half wavelength open circuit line Thus, the oscillation is damped when the frequency varies from the resonant frequency of the resonator

Miniaturized Diplexer for Land Mobile Communication Using High Dielectric Ceramics

Abstract: Miniaturized Diplexer for 800 MHz land mobile communication system has been developed using dielectric quarter wavelength resonator having high permittivity of 37 and 90 The physical volume of diplexer is about 48 cc The Spurious responses of quarter wavelength resonator were shifted to the higher frequencies by stepping the effective permittivity of the resonator material

Spatial and polarization characteristics of radiation from a cw neodymium-doped garnet laser with a nonplanar ring resonator

Abstract: A theoretical analysis is made of the normal polarization modes and of the effect of field rotation outside and inside the resonator of a cw neodymium-doped garnet laser with a nonplanar ring resonator. It is found that, as a result of induced birefringence in the active element, the polarization of the radiation is generally elliptic and only tends to circular when the degree of nonplaneness of the resonator is fairly high. The radiation field is rotated both outside and inside the resonator and the angle of rotation is the sum of two angles defined by the degree of nonplaneness of the resonator and the focal length of a thermal lens in the active element. The transverse modes have a degree of axial symmetry which is a multiple of the total angle of rotation of the field in the resonator. Experimental results confirm these effects.

Specimen head for electron spin resonance and paramagnetic electron resonance measurements

Abstract: A specimen head for electron spin resonance and paramagnetic electron resonance measurements, having an annularly cylindrical resonator, with a waveguide being coupled to one of its end walls in such a manner as to excite an H 011 wave. The other end wall is formed by a piston capable of being shifted for tuning, the piston being attached at the end of a hollow piston rod (6) mounted in a bearing block (4), which also contains the resonator (16), in such a manner that it is concentric relative to the axis of the resonator and longitudinally shiftable. The waveguide (13) is attached to the bearing block (4) on that side of the resonator (16) which is opposite the piston (7) and extends along the outside of the bearing block parallel to the piston rod (6) after having been deflected 180°. Drive shafts (24, 34) for means for shifting the piston (7) and means for altering the coupling of the waveguide (13) are arranged on that side of the piston rod (6) opposite the waveguide (13) in the plane containing the axes of the waveguide and the piston rod (6) and are mounted in or on the bearing block (4). The bearing block (4) is attached to a head member (1) by means of rods (3) extending parallel to the waveguide (13) and to the drive shafts (24, 34), with the free end of the waveguide (13) being attached thereto and the free ends of the drive shafts (24, 34) being mounted therein, and having a hole (48) which is concentric relative to the piston rod (6).

GT-Cut quartz resonator

Abstract: A GT-cut quartz resonator mounted on a pedestal is disclosed. The pedestal has a plural though holes on a predetermined positions. The frequency and the frequency-temperature characteristics of the GT-cut quartz resonator are easily adjusted by depositing masses on the resonator by evaporation and sputtering through the through holes on the pedestal.

Tunable resonator and an ultrahigh-frequency circuit comprising at least one such resonator

Abstract: There is provided a resonator comprising principally a hollow metal finger integral with the wall of a guide or a cavity. A metal plunger, coated with a fine dielectric layer, of fairly low permittivity, is able to slide inside the hollow metal finger to cause the tuning frequency of the cavity or the susceptance coupled to the guide to be varied. This layer may be formed from Teflon.

Multipole SAW Resonator Filters: Elements of Design and Fabrication

Abstract: We are developing VHF multipole SAW resonator filters which are required to have high rejection levels

A Dielectric Resonator Bandstop Filter

Abstract: This paper presents a new analysis predicting accurately the external quality factor and scattering matrix parameters S/sub ij/ of the TE/sub 01p/ cylindrical resonator mode, coupled with a microstrip line for arbitrary locations of the resonator and the line, The results obtained are used to realize a Tchebyscheff bandstop filter. Experimental and theoretical results are also included.

Microwave transceiver, particularly for a doppler radar system

Abstract: In a microwave transceiver including a dielectric antenna and a self-oscillating semiconductor mixer stage for both generating a microwave signal to be transmitted via the antenna and mixing that microwave signal with reflected microwave signal components received by the antenna, the mixer stage being composed of a nonlinear microwave diode connected to give the stage a negative impedance to permit oscillation and to effect mixing, and a half-wavelength disc-type resonator providing a resonant circuit for the oscillator and having the form of a stripline piece element composed of two strip conductors between which the microwave diode is electrically conductively connected, the antenna being disposed on one of the strip conductors, the resonator and antenna are constructed to be axially symmetrical and are positioned coaxially to one another.

Method of measuring the thermal properties of a resonator

Abstract: The thermal properties of a crystal resonator are rapidly and inexpensively measured by first immersing the resonator into an ice water bath at 0° C. and monitoring the frequency of the resonator until the frequency of the resonator is no longer changing; then rapidly immersing the resonator into a boiling water bath at 100° C. and monitoring the frequency versus time characteristic of the resonator at least until the frequency of the resonator is no longer changing; repeating the above cycle, and determining the thermal properties of the crystal resonator from the frequency versus time characteristic.