Showing papers on "Dielectric resonator antenna published in 1982"

All-single-mode fiber resonator.

Abstract: An all-fiber-ring resonator has been constructed using a single strand of single-mode optical fiber and a directional coupler. Derivation of the resonator finesse in terms of fiber and directional coupler parameters is given. A finesse of 80 has been achieved experimentally. Applications of such a fiber-ring resonator are discussed.

Dual-Mode Dielectric Resonator Loaded Cavity Filters

Abstract: A new miniature realization of dust-mode filters is presented. As a basic building element of the filter, the dielectric resonator axially mounted in a waveguide below cutoff and resonating in a hybrid, degenerate mode is used. A dramatic reduction in size and weight, and excellent temperature performance with minimum degradation of resonator Q was achieved. Dust-mode configuration, preferred in satellite applications, allows simple realization of high-performance elliptic function filters. Experimental results are presented and demonstrate excellent agreement with the theory. Bandpass filter configuration is discussed however, realizations of bandstop, directional, etc., filters are also possible.

Polarization effect in optical-fiber ring resonators.

Abstract: The effect of birefringence on the resonance frequency of a closed-loop fiber-optic resonator is calculated.

Wide-band tuner having a temperature-compensated microstrip resonator arrangement

Abstract: A double-superheterodyne tuner for a television receiver comprises a tunable oscillator, a fixed oscillator, two mixer stages and a band-pass filter between the mixer stages, and operates at a GHz intermediate frequency between the mixer stages. The two oscillators and the bandpass filter each includes a microstrip line resonator formed in a dielectric body having substantially the same dielectric constant and dielectric constant temperature coefficient to each other, thereby compensating the variation of the resonant frequency in the resonator due to an ambient temperature variation.

A New Type of Isolator for Millimeter-Wave Integrated Circuits Using a Nonreciprocal Traveling-Wave Resonator

Abstract: A nonreciprocal traveling-wave resonator critically coupled to a waveguide becomes an isolator with high isolation. The dielectric image-line isolator with a magnetized ferrite pillbox as the nonreciprocal traveling-wave resonator is described. The validity of the theory is verified by experiments earned out at the 50-GHz range. The theoretical and experimental estimations of the coupling coefficient between a pillbox resonator and a straight dielectric waveguide are also included.

Microwave resonator structure

Abstract: A microwave resonator is formed by a cylindrical loop and one or more gaps which extend along its length. The loop is formed from a machineable insulating material and a layer of electrically conductive material is deposited over its surfaces.

High-Q microwave properties of a sapphire ring resonator

Abstract: The high-Q microwave properties of a sapphire dielectric ring resonator in the frequency ranges 8-12 GHz and 18-22 GHz at both room temperature and low temperature are discussed. The Q of the resonator is limited significantly below the loss tangent limit, but the frequency stability is excellent when compared with other types of resonator. The results indicate that the sapphire ring resonator should be well suited for use in long-term, high-stability frequency standards, and should also be useful for phase noise stabilisation of microwave sources.

Band selectable tunable bandpass filter

Abstract: A two resonator bandpass filter that is tunable is disclosed with each resonator consisting of three series connected inductors and a tuning capacitors. The inductors comprising each resonator are contained in a common enclosure isolated from each other by a ground shield having a fixed aperture opening for electromagnetic coupling between the two resonators. Shorting plugs are used as the bandswitching techniques for switching the bands of the resonators. Variable capacitors in each of the resonator's circuit provide for tuning of each band to a desired frequency.

Varactor-tuned helical resonator filter

Abstract: A helical cavity resonator filter utilizes varactor tuning diodes positioned within each helical resonator coil. The diodes are positioned along the longitudinal axes of the coils so as not to interfere with the non-axial electromagnetic fields of the cavities associated with each helical resonator coil.

Stabilized radio frequency quadrupole

Abstract: A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

Acceleration-resistant crystal resonator

Abstract: A crystal resonator features two crystals mounted such that the acceleration sensitivity vector of one crystal is in an antiparallel relationship to the acceleration sensitivity vector of the other crystal The composite resonator eliminates acceleration-induced frequency shifts for acceleration in all directions

A multipole magnetostatic volume wave resonator filter

Abstract: A new configuration of a magnetostatic forward volume wave (MSFVW) resonator has been designed and tested. In order to avoid the off-resonance transmission of conventional MSFVW two-port resonators, a component consisting of two resonator sections coupled together through a grating reflecting waves only at the resonator frequency has been implemented. The device is fabricated on an epitaxial yttrium iron garnet (YIG) film grown on a gadolinium gallium garnet (GGG) substrate. Resonators with this configuration designed to operate at 300 μm and 150 μm wavelengths have been achieved and their performances evaluated. Typically, at 3 GHz, the insertion loss is 22 dB ; the rejection near resonance frequency is 15 dB ; the quality factor is ciose to 500 and the response is tunable between 2 GHz and 8 GHz.

Mode Suppressor for Dielectric Resonator Filters

Abstract: The presence of tuning screws can shift spurious modes resonance of the dielectric resonators to frequency close to or even equal to resonant frequency of the principal mode, therefore interfering with the filter's performance. A simple mode suppressing scheme is presented to solve this potentially serious problem.

Analytical and Experimental Considerations on the Resonant Frequency and the Quality Factor of Dielectric Resonators

Abstract: A dielectric pillbox resonator placed on a dielectric substrate is analyzed by a new method, the approximate mode matching method, in which the cross section of such a resonator is subdivided into several sub-sections having a simple geometry of the boundaries, i.e., dielectric slab radial waveguides, and the continuity condition of fields between subsections is treated in the least-squares sense. The resonant frequencies and the intrinsic Q values due to the leakage loss through the dielectric substrate calculated by this method are presented together with experimental results obtained in the 50-GHz region. As a result, it is found that the experimental results for both the resonant frequencies and the Q values agree better with our calculated ones than with the results by other approximate method, and so it will be concluded that the analytical method presented here is almost enough to discuss precisely the resonant characteristics of a dielectric pillbox resonator.

Method for adjusting resonance frequency of dielectric coaxial resonator

Abstract: PURPOSE:To adjust the resonance frequency without deteriorating the Q of a resonator, by removing a part of a short-circuit electrode of the dielectric coaxial resonator using a cylindrical ceramic dielectric. CONSTITUTION:After the length L of the dielectric 11 is polished as 1/4 of the wavelength determined by the resonance frequency fO being the target of adjustment, electrodes 14, 15 and the short-circuit electrode 16 are formed on its inner circumferential surface 12, its outer circumferential surface 13 and its end surfaces respectively, and the resonance frequency fOX is measured. When fOX fO, a part of the short-circuit electrode 16 is polished to form a removed part 22, and the area S is adjusted so as to attain fOX=fO. In decreasing the resonance frequency in this way, since a part of the short-circuit electrode is removed for the adjustment, the resonance frequency is adjusted without deteriorating the Q of the resonator.

Unstable resonator with canceling edge waves.

Abstract: Diffractive feedback from the edge of the output mirror of an unstable resonator can cause intensity spikes and make the resonator sensitive to tilts. A design for a stepped feedback mirror is proposed that substantially reduces the effect of edge diffraction on the resonator modes. The predicted results are a more uniform intensity profile and greatly reduced tilt sensitivity.

Antenna with tunable helical resonator

Abstract: An antenna suitable for use in the high frequency (HF) ranges includes a resonator tunable over a predetermined frequency band. The resonator consists of an insulated wire wound over a dielectric rod. Tuning is effected by sliding a metallic sleeve disposed in frictional contact over the wire. A multiplicity of these resonator units may be mounted on a single collar at different angles. Each of the resonator units will respond to a particular frequency. The remaining devices operate as a load on the antenna assembly. The antenna assembly may also be mounted on a conventional mobile antenna by means of an adaptor unit.

GaAs Monolithic Circuits Mounted Over High Q Dielectric Resonators

Abstract: The coupling of a dielectric resonator through coplanar waveguides is experimentally studied and the feasibility of very selective microwave circuits, where the resonator is placed below the active and passive circuit components, is demonstrated. The design and the operation of high-stability feedback-type coplanar oscillators are reported. The possibility of mounting a monolithic chip over a high-Q dielectric cavity, avoiding unwanted resonator coupling anywhere in the circuit, is demonstrated. This allows the sealing of the overall circuit in a practical low-size case. Finally, the performances of a test monolithic chip carrying two different oscillators are stressed.

Miniature Filters and Equalizers Utilizing Dual Mode Dielectric Resonator Loaded Cavities

Abstract: A novel approach in high performance, dual mode filters and equalizers is described. Miniature, light weight, temperature stable designs utilize dual mode, dielectric resonator loaded cavities. The basic configurations and performance characteristics are presented.

Microwave amplifier tube having two ring resonators

Abstract: A microwave amplifier tube having a first and a second ring resonator of which the first serves as a driver resonator and the second serves as an output resonator. By means of a cathode system an electron beam rotating about the ring axis at the frequency of a control signal is generated. The electron beam is accelerated by a direct voltage and enters the second ring resonator which is tuned to the same frequency as the first resonator. The electron beam influences a high-frequency electromagnetic field in the second resonator and delivers a part of its energy to said second resonator. In order to facilitate equalization of the angular phase velocities in the two resonators, the ring resonators are provided above each other in the direction of the ring axis and the electron beam passes through the first and the second ring resonator parallel to the ring axis.

Trapped energy resonator for oscillator and multiple resonator applications

Abstract: A trapped energy piezoelectric resonator for oscillator and multiple resonator applications has a piezoelectric substrate with electrodes disposed on each of its major surfaces. These electrodes are further comprised of a plurality of electrically interconnected and acoustically coupled sub-electrodes. The resonant frequency of these resonators may be controlled by varying the separation and, therefore, the acoustic coupling between the sub-electrodes. This resonator may be used in the feedback loop of an oscillator circuit as the frequency determining element. It may also be used to provide a resonator on a substrate carrying resonators of significantly different frequency.

Waveguide resonators with a phase-conjugate mirror.

Abstract: A waveguide resonator in which one of the mirrors has been replaced by a phase-conjugate mirror is considered. By using an effective finite mirror size, it is shown that such a resonator is capable of transverse-mode discrimination while providing low coupling loss for the fundamental waveguide mode. It appears that compactness and good beam quality can be achieved simultaneously in a phase-conjugate waveguide resonator.

Modular lumped circuit resonator

Abstract: A structure for supporting a loop-gap resonator includes a cylindrical housing which defines a space into which microwave energy is injected. The resonator is mounted to a support element which is inserted into the space through an opening at one end of the housing. The support element and attached resonator form an interchangeable module.

Method for improving selectivity in cylindrical TE011 filters by TE211 /TE311 mode control

Abstract: A method for designing low loss cylindrical TE 011 mode resonators which permits selective placement of a transmission null at a frequency near the TE 011 resonance frequency. The frequencies of the TE 211 and TE 311 modes, that are naturally excited in the resonator, are controlled by the angular displacement of the resonator input port and output port and by the relative amplitude of the TE 011 mode compared to the TE 211 and TE 311 modes. Proper placement of the transmission nulls improves the selectivity of the TE 011 resonator, and/or can be used to filter out unwanted noise at the frequency of the transmission null. A lumped constant analog circuit model is presented to assist in design of the resonator.

Laser resonator cavity

Abstract: Stability of the optical path in a laser resonator cavity is achieved by means of two reflective surfaces mounted orthogonally with respect to each other, serving as the reflector at one end of the resonator cavity Return and feedback mirrors are rigidly mounted at the opposite end of the aforementioned resonator cavity Changes in relative orientation not self-compensated by the use of orthogonally-mounted mirrors are corrected by means of a real-time servomechanism A typical servomechanism comprises an auxiliary laser mounted rigidly to one end of the laser resonator cavity reflecting a collimated light beam from a reflector mounted rigidly to the opposite end of the resonator cavity The reflected spot is detected by a detector, sensitive to positional changes in the reflected light, rigidly mounted with respect to the auxiliary laser The positional changes of this reflected spot are used to drive a linear translator to correct the relative orientation in real-time

Stabilisation of a W-band microstrip oscillator by a dielectric resonator

Abstract: The effect of temperature on the performance of a dielectric resonator compensated W-band impatt diode microstrip oscillator is shown to be quite small. The frequency change was about 2 MHz/°C as compared to the uncompensated oscillator's 10 MHz/°C. The design of the oscillator is presented and the resonator used was a cuboid of temperature compensated barium nonatitanate.

Hybrid-mode analysis of a microstrip-slot resonator

Abstract: A hybrid-mode analysis is presented for obtaining resonant frequencies of a microstrip resonator with a tuning slot; namely, a microstrip-slot resonator, which has a microstrip and a tuning slot on each side of the substrate, respectively, and whose special case is a microstrip resonator. The analysis is based upon Galerkin's method in the Fourier transform domain. The sensitivity of the solution is investigated with respect to the basis functions. The computed resonant frequencies, using simple basis functions, are compared with the experimental values on alumina substrate in the frequency range 3?7 GHz.

A 50 GHz Mic Transmitter/Receiver Using a Dielectric Resonator Oscillator

Abstract: A compact and low cost 50 GHz transmitter/receiver has been developed for a 10.7 Mb/s digital radio system. The output power of the transmitter is 5 dBm. A dielectric resonator is utilized for the 50 GHz oscillator, obtaining a frequercy stability of less than +-100 PPM (0 °C - 50°C). These circuits are integrated on Fine Grained Alumina FGA) substrates. The size of the transmitter/receiver is 54x48x15 millimeters.

Submillimeter-wave dielectric measurements using an open-resonator

Abstract: The open resonator method for dielectric measurements is developed in the submillimeter-wave region. This method, different from usual laser methods is based on the sweeping of resonator length. The conventional theory developed in the millimeter-wave region is improved so as to make measurements possible with resonable precision even in this frequency region and the design criterion of an optimum resonator at around 890 GHz (λ0=337μm) is presented. Finally, the measurements are performed for several kinds of low loss material and it is confirmed that the present method becomes a useful one in the submillimeter-wave region.