Showing papers on "Dielectric resonator antenna published in 1978"

A Highly Stabilized Low-Noise GaAs FET Integrated Oscillator with a Dielectric Resonator in the C Band

Abstract: A GaAs FET integrated oscillator stabilized with a BaO--TiO/sub 2/ system ceramic dielectric resonator provides a high-frequency-stabilized low-noise compact microwave power source. The newly developed ceramic has an expansion coefficient and dielectric constant temperature coefficient that offset each other and result in a small resonant frequency temperature coefficient. A stabilized oscillator output of 100 mW with a 17-percent efficiency and a frequency temperature coefficient as low as 2.3 ppm//spl deg/C are obtained at 6 GHz. FM noise level is reduced more the 30 dB by the stabilization. The dynamic properties of the oscillator and resonator are precisely measured to determine equivalent circuit representations. A large-signal design theory based on these equivalent circuit representations is presented to realize the optimal coupling condition between the oscillator and stabilizing resonator. The stabilized oscillator performance is sufficient for application to microwave communications systems.

Microwave distributed-constant band-pass filter comprising projections adjacent on capacitively coupled resonator rods to open ends thereof

Abstract: A microwave distributed-constant filter of a band-pass characteristic having at least one attenuation pole comprises resonator rods, each of which has an open and a shorted end and of which two first are inductively coupled in series through at least one second resonator rod. The first resonator rods are capacitively coupled direct to each other with a projection attached adjacent on at least one of the first resonator rods to the open end thereof. The first resonator rods may be coupled directly to input and output terminals of the filter. Alternatively, two third resonator rods may be interposed between the respective ones of the first resonator rods and the input and the output terminals. The third resonator rods may be inductively coupled direct to each other. As a further alternative, two fourth resonator rods may be interposed between the respective ones of the third resonator rods and the input and the output terminals with the third resonator rods inductively coupled direct to each other or with the third resonator rods capacitively coupled direct to each other by a projection attached adjacent on at least one of the third resonator rods to the open end thereof. The filter may be of the various coaxial types including the interdigital type.

Stripline filter device

Abstract: Stripline filters and the like have one or more elongated resonator conductors positioned on a dielectric substrate which is backed by a ground plane conductor, with the response frequency being dependent primarily on the length of the resonator. A wide apron conductor is connected to the grounded end of the resonator and to the ground planes. The resonator and apron can be formed by use of a mask such that errors in alignment of the mask do not change the length of the resonator or the point of connection to the grounding apron. The apron, because of its width, has low transmission line impedance to the ground plane which is not changed by changes in configuration or position of the mask, so that it effectively grounds the resonator at the end thereof connected to the apron. A second dielectric substrate backed by a ground plane conductor may be placed on the resonator conductor. The filter may have a plurality of resonators connected to grounding aprons, and a plurality of resonators can be connected to the same apron. In this case it may be desired to place a notch or cut-out in the apron between the connection of the resonators thereto, to interrupt spurious couplings between such resonators through the apron.

Dielectric resonator stabilized micro-strip oscillators

Abstract: Dielectric resonator stabilized micro-strip oscillators in which micro-strip lines are provided to the first, second and third terminals of the active element for oscillation and in which a dielectric resonator coupled at a predetermined position to one of the micro-strip lines which is not used as an output terminal is disclosed. In the integrated microwave oscillator, there is an active element for oscillation such, for example, as GaAs-FET having first, second and third terminals. Micro-strip lines connect to the first and third terminals, and a micro-strip line connected between the first and third terminals form a feedback circuit, together with the first mentioned micro-strip lines. A dielectric resonator is coupled to one of these micro-strip lines which is not used as an output terminal at a predetermined location.

Fabry-Perot resonator using a birefringent crystal

Abstract: The cleavage planes of a lithium niobate crystal (100) are used to provide the parallel surfaces (121 and 122) of a Fabry-Perot resonator established in a titanium diffused waveguide (110). To enable use of the extraordinary wave and therefore to provide a higher efficiency resonator, the waveguide is diffused into the crystal at a predetermined oblique angle (Ψ) with respect to the cleaved ends. The resonator is utilized in an optically pumped laser and in an electrically controllable Fabry-Perot resonator wherein the reflection provided by the cleaved ends is supplemented by multilayered dielectric mirrors (201 and 202 or 301 and 302) that are bonded to each of the cleaved ends. In the electrically controllable resonator a dielectric layer (330) is deposited over the surface of the crystal before electrodes (310 and 311) are formed on the layer parallel to the waveguide.

Piezoelectric overtone resonator with at least a convex surface and specific thickness and diameter or diagonal

Abstract: In the use of a resonator as an overtone crystal of an aperiodic oscillator circuit without additional selection means, by dimensioning of the resonator itself and its electrodes, suppression particularly of the fifth harmonic during operation of the resonator with the third harmonic is improved by means of special resonator dimensions.

Resonator for high frequency electromagnetic oscillations

Abstract: A resonator for a high frequency electromagnetic oscillator is disclosed The resonator includes a hollow cylinder formed of a material having a low dielectric constant and a dielectric wire formed of a material having a higher dielectric constant and located within the cylinder The dielectric wire has a length similar to that of an open half-wire coaxial resonator or a whole number of multiples thereof The dimensions of the wire are chosen as a function of the dielectric constants of the hollow cylinder in the dielectric wire as well as the desired resonant frequency such that a standing TEM-wave is established in the hollow cylinder and a E 0m -wave (circular magnetic field, m=1,2,3 ) is established in said wire

Very High-Q, Dielectric Resonator Voltage-Controlled Oscillators

Abstract: A new technique for frequency modulation by a dielectric resonator microwave oscillator is described here. To modulate with a very high-Q dielectric resonator oscillator, a microwave ferrite is attached to the dielectric resonator. Results of experiments showed that this VCO has excellent characteristics.

Cascaded plasma tube ion laser having single resonator structure

Abstract: A gas ion laser is described having two separate plasma tube assemblies serially aligned with one another between a single set of optical reflectors, i.e., in a single resonator. Unbalanced stresses on the resonator due to the forces of gravity on the separate plasma tube assemblies are obviated by appropriately locating the mounting structure connecting the resonator to the laser base. Each of the plasma tube assemblies is so connected to the resonator structure that its axial alignment within the same can be adjusted. Moreover, a vernier drive arrangement for adjusting the angular orientation of the optical reflectors relative to one another is provided.

Multipath Raman cell for wavelength conversion

Abstract: The wavelength of an optical pump beam is down converted to a longer wavelength in a Raman active gaseous medium by stimulated Raman scattering. The Raman active gaseous medium is contained in the space between a pair of optical reflectors of an optical resonator of the type for producing a focus of the optical beam energy at a point intermediate the length of the resonator within the Raman active medium to enhance conversion of pump energy into the output longer wavelength of the Stokes wave. The pump beam is directed into the optical resonator at an angle to the optical axis of the optical resonator such that the optical beam path is folded back and forth within the optical resonator to cause the beam spot to walk over the surfaces of the reflectors and out of the optical resonator. The multipass Raman cell of the present invention is particularly useful for down converting pump wave energy in the infrared at relatively high power levels to Stokes wave infrared energy of longer wavelengths, such as at 16 microns, for producing a dissociation of molecules as may be employed for isotope separation.

Dielectric resonator-common plane type line coupling circuit

Abstract: PURPOSE:To make easy the fine tuning of resonance frequency by placing the dielectric resonator on the dielectric plane absent from the common plane type line. CONSTITUTION:Since the coupling between the common plane type line 3 and the dielectric resonator 2 is made via the dielectric substrate 1, when the resonator 2 is fixed on the substrate 1, the fixing means through the bonding of the dielectric substances is possible for adoption to eliminate the effect of conventional conductor loss. Further, the resonator 2 can be inserted or built in by making a hole 7 to the dielectric substrate 1 and the coupling between the slot line 4 and the resonator 2 can freely be changed with the depth of the hole 7. Moreover, since the resonator 2 is placed on the substrate 1, the resonant frequency can easily be fine-adjusted on the circuit constitution.

Measurement of the extinction cross-section of dielectric spheres using an open resonator

Abstract: The measurement of the extinction cross-sections at microwave frequencies for a set of spheres made of low-loss dielectric material is reported. Measurements were carried out at Q-band using a microwave open resonator. Results are compared with calculated values derived from Mie's theory.

Response of an Optical Resonator with Distributed Bragg-Reflectors to Light Pulses

Abstract: The response of an optical resonator with distributed Bragg-reflectors (DBR) to light pulses are analyzed in terms of time-dependent coupled-wave equations. Transmission and reflection properties of optical pulses are calculated for various of the input pulse width, the optical wavelength, the coupling coefficient of the corrugated waveguide, and the distance between two Bragg reflectors. It is shown that the pulse shapes of transmitted and reflected waves are quite distorted by the dispersion characteristics of the corrugated waveguide, if the input pulse width is comparable to the transit time of the optical resonator. Optical pulses whose width is, for example, 10 times the transit time of the optical resonator, suffer little distortion during propagation in the optical resonator.

Resonances of a "Pillbox" Dielectric Resonator

Abstract: Resonant frequency, quality factor and field plots are discussed for a circular-cylindrical dielectric resonator. These quantities are calculated in the limit ?r ??. The method is a perturbation technique based on an expansion in the (small) parameter (1/??r). Data are shown for the lowest modes of revolution, which are either of the electric dipole (TM) or the magnetic dipole (TE) type.

Design theory of high-Q optical ring resonator with asymmetric three-layered dielectrics

Abstract: An optical ring resonator with asymmetric three-layered dielectrics is shown to have an anomalously highQ-factor compared with the conventional symmetric three-layered ring resonator by several orders of magnitude for suitably chosen parameters. A new leaky mode which can propagate on the asymmetric structure is found having an extremely small attenuation loss near the cut-off frequency of the guided mode, but which does not exist in the symmetric structure. Optimum values of the normalized frequency for a single-mode operation to suppress the undesired leaky modes are discussed. It is also shown that the size of the ring resonator using the asymmetric structure can be reduced considerably from that of the ordinary symmetric resonator.

Microwave oscillator circuit with Gunn or IMPATT diode - has diode in cavity resonator to produce continuous or pulsed millimetre waves

Abstract: The microwave oscillator has a negative impedance device, e.g. a Gunn or IMPATT diode. The diode is located in a cavity resonator and produces continuous or pulsed millimeter waves of e.g. 35 GHz. The diode (4) is located in the centre of a normal section of waveguide acting as a cavity resonator. There is a filter resonator (2) which prevents power passing out via the DC supply line of the diode. An impedance transformer (3) is located on the opposite side to the diode earth connection to match the diode to the cavity resonator.

New type of band-pass filters for mobile radio communication equipment

Abstract: This paper describes compact band-pass filters for duplexer of 900 MHz high capacity mobile radio communication equipment. Band-pass filters developed here are constructed with a newly developed resonator of which Q-factor is higher than conventional capacitor-loaded resonators especially in the range of the small size resonator. Another type of filter with this resonator is fabricated using high dielectric material which was developed for the purpose of resonators at microwave frequency.

6-12GHz Transmission Type Dielectric Resonator Transistor Oscillators

Abstract: This paper discusses the design of 6-12GHz dielectric resonator transistor oscillators using the concept of transistor negative resistance and their frequency tuning range which satisfy the required frequency stability. The various types of dielectric resonator oscillators are briefly described.

Microwave Transistor Oscillators Stabilized with Dielectric Resonator (Panel Discussion)

Abstract: Owing to their high thermal stability and high Q value, BaO-TiO/sub 2/ system ceramic resonators have been investigated as frequency controlling devices and are now in practical use. Relatively high dielectric constant makes it possible to obtain a small size resonator which is compatible with stabilized oscillator design. Dielectric resonators are readily incorporated into MIC transistor oscillators and result in a highly-stabilized, low-noise microwave power source.

Effect of a dielectric film on the characteristics of an open Fabry-Perot resonator cavity

Abstract: It is demonstrated that placing a thin dielectric film inside the cavity of an open Fabry-Perot resonator, at an angle to its axis, will remove the polarizational degeneracy of the principal TEMq00 oscillation modes. Upon excitation of such a resonator cavity by a plane wave, the reflected electromagnetic field is in general elliptically polarized. The shape of the resonance curve depends on the thickness of that film, on its orientation inside the cavity, on the conditions under which the cavity has been excited, and on the conditions under which the reflected signal appears in the receiver. Changing the polarization plane of the incident plane wave does not result in a smooth variation of the resonator Q factor.

Electromechanical filter with extra wire resonator - has electromechanical transducers with flexural mode wire resonators

Abstract: The mechanical filter consists of electromechanical transducers and flexural-mode resonators each with two nodes, one or both of which are used to mount the resonator. An extra mechanical resonator (8) is attached to one of the two nodes (irrespective of whether that node is used for mounting or not). If that node has no support then the extra resonator is a wire at right angles to the resonator's axis. If that node has a support leg than the extra resonator is a wire at right angles to the leg. This avoids breaks in the filter's blocking curve.

A New Type of Dielectric Resonator Filter

Abstract: This paper discusses a new type of dielectric resonator filter wherein the cylindrical dielectric resonators have been enclosed in evanescent cylindrical metallic cavities. The electromagnetic fields inside the metallic cavity have been derived assuming the dipolar TE01p dielectric resonator as a density of magnetic moment centered inside the metallic cavity. Coupling between two such cavities has been determined and a two cavity filter has been realised which shows good agreement with the theoretical results.