Showing papers on "Dielectric resonator antenna published in 1986"

Oscillator having stripline loop resonator

Abstract: A high frequency oscillator comprising a ring type inductive resonator of a microstrip line constituted in a rectangular or annular loop. Capacitors are serially connected to both ends of the line, thereby improving the low-noise, separation and stability characteristics by use of the steep-phase characteristic of the ring-shaped resonator.

A New Method for Measuring Dielectric Constant Using the Resonant Frequency of a Patch Antenna

Abstract: An analytical expression is given for the resonant frequency of a rectangular patch antenna. It shows explicitly the dependence of the resonant frequency on the characteristic parameters of a patch antenna. Based on this result, a new method is developed for the measurement of the dielectric constant of a thin slab substrate. Basically, the test equipment consists of a rectangular microstrip antenna the patch of which is fed either by a microstrip line or coaxial line. From the measured resonance parameters of the rectangular patch antenna, the dielectric constant can be easily obtained. The measured values of the present method are in agreement with the precision standard cavity resonator method. Accuracy of the dielectric constant so obtained is satisfactory.

Semiconductor laser devices

Abstract: It is possible to narrow the emission spectrum linewidth of a semiconductor laser device by coupling optically an external resonator with one end surface of the semiconductor laser. However, the structure of the external resonator should match the phase of the light emitted by the laser. Heretofore, this matching has been effected by adjusting the length of the external resonator, and hence productivity and reproducibility have not been good. According to this invention, characteristics of the external resonator can be adjusted electrically to be matched with the phase of the emitted light owing to the fact that the external resonator is made of a material, whose refractive index can be varied electrically. Therefore the semiconductor laser device according to this invention is very practical.

Radio frequency filter having a temperature compensated ceramic resonator

Abstract: An RF filter (100) includes a ceramic resonator (116) sandwiched between first and second compensating discs (114 and 120) for temperature compensation, low loss mounting and heat sinking of the ceramic resonator (116). Good thermal contact between the ceramic resonator (116) and discs (114 and 120) is produced by a compressive force applied by copper plates (112 and 128) and copper can (124). The resonant frequency of the RF filter is tuned by means of a copper-plated tuning shaft (104) and ceramic tuning slug (118) which are positioned by brass bushing (134) in copper pipe (130 and 132). Input and output signals are coupled to the RF filter via respective probes (122).

Recent Advances in Monolithic Film Resonator Technology

Abstract: During recent years, work has been progressing toward the development of stable, high-Q, acoustic resonators capable of operation in the UHF band. The aim of these efforts is twofold: (1) circuit simplification and performance improvement associated with stable signal generation and narrow-band signal sorting directly at UHF, and (2) resonator volume reduction and potential use as an MMIC circuit element. In the latter case, the resonator can be formed by sputter deposition of a piezoelectric film directly onto supporting membranes formed in semiconductor substrates. The resonator equivalent circuit consists of a clamped capacitance in parallel with a series combination of motional inductance, capacitance, and resistance. The motional branch-Q and clampedto-motional capacitance ratio are two important performance parameters whose ratio constitutes a figure of merit (FOM) that defines device usefulness in oscillator and filter circuitry. One-dimensional resonator analysis provides valuable insight regarding the effects of film-to-membrane layer thickness ratio, electrode placement within the layers, and vibrational mode on the resulting resonator FOM. In connection with extending device operating frequencies, analysis results indicating high obtainable FOM for resonator harmonic vibrational modes are of particular interest. In this paper, we discuss relationships between resonator FOM and obtainable filter and oscillator electrical performance, including practical methods of achieving desired circuit performance using low FOM devices. Results of resonator one-dimensional analysis are presented and compared to measured characteristics. Included is a description mode of ZnO on SiO, resonators exhibiting exceptionally good performance in the second harmonic mode. Several of these devices have been used to construct hybrid two- and three-pole ladder filters having 1% to 3% bandwidth at 700 MHz.

Method of making a resonator having a desired frequency from a quartz crystal resonator plate

Abstract: A resonator having a desired frequency is made from a quartz crystal resonator plate by a method including the steps of: (A) etching the quartz crystal resonator plate to a frequency slightly higher than the desired frequency, (B) vacuum desposting metallic electrodes onto the active area of the resonator plate to lower the frequency to a frequency that very closely approaches the desired frequency, and (C) treating the plate with the deposited electrodes with UV-ozone to oxidize the electrodes in a slow, precisely controlled manner to the desired frequency.

Ring resonator fabricated in phosphosilicate glass films deposited by chemical vapor deposition

Abstract: The design and fabrication of a closed loop (ring) resonator is described. The resonator was fabricated in phosphosilicate glass films deposited by chemical vapor deposition onto oxidized silicon substrates. A channel waveguide-to-channel waveguide tapered mode directional coupler was used to transfer light from the input channel to the ring. To our knowledge this is the first demonstration of the use of such a coupler for coupling between channel waveguides. An analysis is presented for power distribution in the channels of the coupler, for stored, reflected and transmitted powers in the resonator and for resonator finesse. Operation of the resonator was demonstrated experimentally and finesse values of less than 3, comparable to those published elsewhere in the literature, were obtained.

Interdigital duplexer with notch resonators

Abstract: A duplexer includes an integral interdigital transmitter filter and parallel interdigital receiver filter in a common housing. A three-quarter wavelength antenna transformer section couples rf energy from the transmitter filter to an antenna and also couples rf energy from the antenna to the receiver filter and to an antenna cable connector. The receiver filter selectivity is improved by providing a notch resonator between a receiver transformer section and the housing, and the transmitter filter selectivity is improved by providing a notch resonator between a transmitter resonator and the housing.

The input impedance of the dielectric resonator antenna

Abstract: Dielectric cylinders of very high permittivity have been used in the past as resonant cavities, but since the structure is not enclosed by metallic walls, electromagnetic fields do exist beyond the geometrical boundaries of the structure and part of the power is radiated. Through the proper choice of geometry and permittivity this radiation can become the dominant feature of the structure and become an efficient antenna for use at millimeter wave frequencies. Both experimental and theoretical investigations of a variety of these dielectric resonator antennas have been undertaken. In particular, the input impedance of a probe-fed cylindrical structure was examined in detail and a comparison of theoretical and experimental results was made.

Oscillator coupled through cylindrical cavity for generating low noise microwaves

Abstract: A microwave oscillator having very low phase noise characteristics has a reflection oscillator circuit coupled to a right-circular cylindrical resonant cavity designed to operate in the TE011 mode. The resonator length L and inner diameter D are restricted to a range of values such that (D/L)2 is less than 2.5 but greater than 1.7. To suppress the TM111 resonant modes in the resonator, two techniques are employed. A single tuning post is disposed on either resonator end plate at a point where the TM111 electric field Z-component is a maximum. The post length is adjustably fixed to maximize the output microwave power at the cavity output port. Each end plate also has a continuous gap separating each plate from the housing to suppress electric field currents of the TM111 mode flowing on the inner surface of the resonator.

Transmission injection-locked dielectric resonator oscillator

Abstract: A dielectric resonator oscillator utilizing transmission-type injection-locking for frequency stabilization is disclosed as including a transistor, two microstrip lines, and a dielectric resonator. One microstrip line is coupled to the transistor, while the other microstrip line receives the broadband signal. The dielectric resonator is positioned adjacent to and between the first and second microstrip lines and is operable for coupling an injection-locking signal into the transistor for locking the oscillation frequency of the oscillator. The two microstrip lines are preferably oriented at right angles so that various sizes of the dielectric resonator can be accommodated.

Asymmetrical trap comprising coaxial resonators, reactance elements, and transmission line elements

Abstract: An improved asymmetrical trap which includes at least one dielectric material coaxial resonator, a capacitor inserted between an inner conductor of the coaxial resonator and a first signal transmission line, with an outer conductor of the coaxial resonator being grounded so as to produce a series resonance at a first frequency through the combination of the capacitor and coaxial resonator, and a second transmission line connected, at their corresponding ends, in parallel with opposite ends of the series connection of the coaxial resonator and capacitor, and opened or short-circuited at their other far ends, so that anti-resonance is produced at a second frequency through the combination of the capacitor, coaxial resonator and second transmission line.

Influence of an airgap on the measurement of dielectric constant by a parallel-plate dielectric resonator

Abstract: The use of higher resonant modes, other than tradiationally used TE011 is discussed in connection with the so-called Courtney method of measuring the relative dielectric constant of dielectric resonators. An error analysis is developed, which takes into account also the presence of an airgap between the dielectric resonator and the two parallel metal plates.

Dynamically one-mode semiconductor laser

Abstract: A dynamically one-mode semiconductor laser having a laser diode with a coupled external resonator includes a resonator mirror disposed opposite a light emitting face of the laser diode and a collimation optics between the diode and the resonator mirror. The collimation optics includes a refractive hemispherical micro-lens having flat side applied to the resonator mirror which is manufactured by fusing a small drop of glass onto the resonator mirror.

Adjustable dielectric resonator, especially for a microwave oscillator, and process for adjusting such a resonator

Abstract: 1. Adjustable dielectric resonator of the type comprising a dielectric resonator (1) contained in a conductive closed housing (60) comprising a substantially plane ceiling (50) which is parallel to the upper face of the resonator, characterized in that the ceiling (50) of the housing is susceptible to be deformed in permanent manner during manufacture in order to approach its portion adjacent to the resonator (1) to the upper face thereof without deforming the other portions or the housing, whereby the resonance frequency of the resonator is increased until the desired adjustement value is reached.

Third mode torsional F-M resonator

Abstract: There is disclosed an improved electromechanical resonator for use in multiresonator mechanical bandpass filters. The resonator is constructed using two resonator rods attached to a ceramic transducer which is substantially centrally located. The thus-formed electromechanical resonator resonates at the desired frequency in the third torsional mode, which is characterized by three motional nodes. Support pins are attached at the two outer nodes to provide physical support, and are also used for signal and ground connections, while the ceramic is positioned on or near the center node, which maximizes the achievable electromechanical coupling. Multiresonator mechanical bandpass filters which use such third-mode electromechanical resonators in conjunction with second-mode interior resonators have improved spurious rejection.

Dielectric and permeability effects in HE111 open demagnetised ferrite resonators

Abstract: The half-wave HE111 open ferrite or dielectric resonator, open circuited or loaded by image walls at each end, is a common building block in the construction of waveguide circulators and other devices. Its resonant frequency is usually evaluated by catering for the image wall effect but neglecting that of the open lateral wall. The latter omission is largely reconciled in this paper by employing an equivalent waveguide model for the resonator which has the same radius as the original but with an effective instead of the constitutive dielectric constant. The import of the diagonal elementμd of the demagnetised resonator is separately catered for.

Circulator/isolator resonator

Abstract: A microstrip resonator (311) for a circulator/isolator is disclosed employing radial (815, 817, and 819) and circumferential (821, 823, and 825) slots to load the resonator and reduce the frequency of resonance. A resonator of small physical size is thus formed having a discontinuous outer ring (segments 807, 809, and 811) and a central triangle portion (827) each electromagnetically coupled to a ferrite element.

Method and apparatus for increasing the turbulence in a gas exposed to low frequency sound

Abstract: Method and apparatus for increasing the turbulence in a gas exposed to low frequency sound. The gas is exposed to sound produced by a sound generator (10) which has a tubular resonator (11) having an open end and is operated at one of the resonance frequencies of the resonator having a maximum frequency of 150 Hz. The gas is flown into the tubular resonator through the open end thereof and is discharged from the resonator substantially in a region, where the sound pressure of the standing wave in the resonator has a node, after having passed through a substantial length of the resonator.

High-power laser having an unstable optical resonator

Abstract: A high-power laser, especially one with a gaseous excitation medium, having an unstable optical resonator is disclosed. Fully reflecting mirrors, whose planes of curvature are parallel to one another, form the ends of the unstable optical resonator. A third mirror is concavely curved in a plane perpendicular with respect to the other two mirrors. The mirrors have a rectangular cross section and are preferably metallic. The mirrors constituting the ends of the unstable optical resonator form a confocal resonator.

Oscillator having improved coupling between stripline and dielectric resonator

Abstract: An oscillator with a dielectric resonator capable of providing a designated output and being suited for mass production comprising an insulating substrate, a strip structure, a dielectric resonator located adjacent to the strip structure, the last two being mounted on the substrate, and an oscillatory transistor connected to one end of the strip structure. The strip structure consists of two spaced strip sections interconnected by an electrically-conductive bridge-shaped connector section having a conductor part, which is located further away from the insulating substrate and closer to the dielectric resonator than the two strip sections.

Single-mode laser

Abstract: The invention relates to a single-mode laser provided with a folded optical resonator, comprising a laser rod 1, resonator mirrors 3A, 3B deposited by evaporation on a single mirror plate 3, a stop 6 provided with two separate apertures 6A, 6B which are overlapped by the laser rod 1 when they are viewed along it and which are located so that the rays traversing the aperture 6A or 6B towards the resonator mirrors 3A, 3B, respectively, completely impinge only on the high reflecting resonator mirror 3A or on the semitransparent resonator mirror 3B, a foil Q-switch 5 and a reversing prism 4. The device according to the invention is compact, of moderate price and is provided with a dynamically stable optical resonator, it generating single-mode laser pulses with a divergence below 2 mrad, but with an energy about 15 mJ and with a width about 10 nsec. The device according to the invention is intended for use e.g. in ophthalmology or elsewhere where the laser pulses characterized above are required.

Detecting method by microwave for conductive foreign matter present in dielectric penetrating through resonator

Abstract: PURPOSE: To improve foreign matter detection sensitivity by passing a sample along the electric field of a resonator and increasing an in-use frequency. CONSTITUTION: Holes 2 1 and 2 2 are bored in the barrel wall of a cylindrical cavity resonator and the sample is passed through them. A microwave sweep signal is applied from an input terminal 4 and the resonance mode is so set that the sample is along the electric field. The resonance output is led out from an output terminal 5 and variation in its resonance frequency and resonance amplitude are monitored on the screen of an oscilloscope or monitored continuously without any operator by using a simple computer circuit. When a dielectric is moved along the electric field of the resonance electromagnetic field of the resonator 1, etc., a normal sample and a sample containing foreign matter has an electromagnetic difference, so the difference is detected as variation in resonance frequency and reflected wave electric power, or insertion loss or impedance to recognize the presence of the foreign matter. COPYRIGHT: (C)1988,JPO&Japio

Mechanically tunable sealed microwave oscillator

Abstract: A microwave oscillator has a sealed, dielectric case that encloses a dielectric resonator adjacent a circuit conductor. Discrete conductive elements are removably mounted to the exterior of the case within a magnetic field generatable by the resonator. The oscillator may be tuned by selectively removing the discrete conductive elements from the case.

Varactor tuning circuit for dielectric resonator stabilized oscillator

Abstract: Tuning varactor circuitry is disclosed for a dielectric resonator stabilized oscillator (2). A varactor diode (22) is electrically connected in a loop (24) with an RF bypass capacitor (26), and the voltage across the diode is varied. In a first embodiment, first and second dielectric substrates (36, 38) face each other along the plane of the loop (24), with the loop (24) therebetween. In another embodiment, the loop (24) is around a peripheral side wall (52) of the dielectric resonator substrate (46). In another embodiment, the loop (24) is formed on the same surface (54) of a microstrip circuit substrate (56) with a transmission line (10).

Automatic technique for the characterisation of a dielectric resonator coupled to a microstrip line

Abstract: An automatic computer controlled technique is proposed to measure the resonant frequency, loaded quality factor and coupling factor of a dielectric resonator coupled to a microstrip line. The complex transmission coefficient of the system is measured, as a function of frequency, by means of a network analyzer. At each frequency, the reflection coefficient is calculated and its magnitude is processed to obtain the characteristic parameters of the resonator. Estimated errors for Q- and coupling factors are in the order of 1% and for the resonance frequency are about 1 part in 106.

Attenuation and delay equalizer for a waveguide filter

Abstract: An arrangement for the equalization of attenuation and time delay in a microwave filter utilizing waveguide technology. An equalizer composed of a multi-circuit cavity resonator is coupled via a first coupling aperture to a waveguide which is connected to the filter. The resonator includes at least two individual waveguide sections coupled to each other via a second coupling aperture. The coupling apertures are dimensioned so that the resonator is critically coupled with respect to time delay characteristics. The resonator includes a power-absorbing tuning device for tuning all of the waveguide sections to substantially the same quality factor. The second coupling aperture presents a stepped cross section defining a first area and a second area having a larger cross section than the first area. The resonator further includes at least two screws arranged symmetrically with respect to the longitudinal axis of the resonator and protruding laterally into the second area of the second coupling aperture. The screws influence the time delay of the equalizer as a function of their depth of penetration into the second area.

Dielectric resonator controlled oscillator having a raised frequency multiplying efficiency

Abstract: In a dielectric resonator controlled oscillator with frequency multiplication, a line (12) has an open end and another end connected to a gate electrode of an FET (11) with a dielectric resonator (13) electromagnetically coupled to the line at a location along a total length of the line. The total length is selected to make a combination of the line and the dielectric resonator have a substantially zero impedance for a higher harmonic frequency when seen from the gate electrode. More specifically, the total length is selected so as to be equal to about three quarters of a wavelength which a frequency multiplied oscillation, such as a frequency doubled oscillation, has in the line. The location is selected so as to optimize the oscillator for a fundamental oscillation of a fundamental frequency determined by the dielectric resonator.

Realization of an Exact 5-Pole Elliptic Function Filter Employing Dielectric Loaded Triple-Dual-Mode Cavity Structure

Abstract: A novel 5-pole symmetrical elliptic (with four transmission zeros) dielectric resonator filter has been built, using a cascade of a triple-mode and a dual-mode cavity and an unconventional resonant cross-coupling screw structure. Such a structure offers performance improvement over existing designs and makes it an attractive candidate for output multiplexer applications for future C-band satellite systems.