Magnetostatic Wave Resonators Research Articles

Octave-Tunable Magnetostatic Wave YIG Resonators on a Chip.

We have designed, fabricated, and characterized magnetostatic wave (MSW) resonators on a chip. The resonators are fabricated by patterning single-crystal yttrium iron garnet (YIG) film on a gadolinium gallium garnet (GGG) substrate and excited by loop-inductor transducers. We achieved this technology breakthrough by developing a YIG film etching process and fabricating thick aluminum coplanar waveguide (CPW) inductor loop around each resonator to individually address and excite MSWs. At 4.77 GHz, the 0.68-mm2 resonator achieves a quality factor ( with a bias field of 987 Oe. We also demonstrate YIG resonator tuning by more than one octave from 3.63 to 7.63 GHz by applying an in-plane external magnetic field. The measured quality factor of the resonator is consistently over 3000 above 4 GHz. The micromachining technology enables the fabrication of multiple single- and two-port YIG resonators on the same chip with all resonators demonstrating octave tunability and high Q .

CPW Cascaded Magnetostatic-Wave Bandstop Resonators

Magnetostatic-wave resonators in bandstop configuration have been studied by using a coplanar waveguide transmission line to excite the resonating signal. The microwave performances of such a device have been discussed and implemented by using cascaded resonators, to improve the microwave absorption and the selectivity response of the entire structure

Micromachined magnetostatic wave coupled resonators

Coupled magnetostatic wave resonators realized by means of micromachining techniques are proposed as integrated structures for microwave narrow-band filtering. Theory, technology, and test of two-resonator configurations are described in this paper.

Band-stop magnetostatic waves micromachined resonators

Band-stop magnetostatic wave (MSW) resonators based on microstrip transducers realized on low-resistivity silicon (LRS) wafers and on micromachined silicon membranes have been studied. Frequency tunable MSW straight edge resonators made of yttrium–iron–garnet film have been used as selective frequency components. The frequency tunability ranged between 5 and 7.5 GHz for bulk devices and between 3.5 and 9.5 GHz for the membrane supported ones, with better rejection and wider bandwidth with respect to the bulk configuration. From measurements of the transmission parameter suppression of more than 20 dB of high-order modes and a rejection ratio better than 20 dB for the membrane supported resonators have been obtained. As a result, the possibility to manufacture microwave resonators characterized by high rejection ratios on low-cost, LRS membranes is demonstrated.

Electrodynamic Theory of Magnetoelectric Particles on the Base of Strip-Line-Coupled Magnetostatic Wave Resonators

Electrodynamic description of bianisotropic particles on the base of strip-line-coupled magnetostatic wave resonators is developed and analytical closed-form expressions for the tensor polarizabilities are obtained for an arbitrary direction of the bias magnetic field and an arbitrary resonator shape. Numerical calculations are performed for a normally magnetized thin-ferrite-film disk resonator with a metal strip on its surface. The principle of the symmetry of kinetic coefficients (the Onsager-Casimir principle) is formulated for media containing dissipative ferrite inclusions and on its base results of the electrodynamic analysis for the tensors of magnetoelectric coupling coefficients are verified.

A generalized lumped element modeling of magnetostatic wave resonators

A lumped element modeling of a typical distributed electromagnetic structure, namely a band-stop magnetostatic wave resonator, is presented here and validated by experimental results. The definition of a turns ratio and data on the quality factor of the resonator versus frequency allow a wideband approach to the prediction of its performances between 1 and 12 GHz.

Plane-wave solutions for homogeneous bianisotropic media described by the magnetic groupD?h(C?v)

Constitutive tensors of bianisotropic media described by continuous magnetic groups of symmetry have been recently determined. One of these groups is D∞h(C∞v). A medium with this symmetry may theoretically be synthesized using Kamenetskii's magnetostatic wave resonators with metallization. The moving isotropic medium is a special case of media described by the group D∞h(C∞v). In this paper, we investigate plane-wave propagation in such media. The dispersion equation for the media is obtained, and solutions of this equation are found and discussed. The results are verified by some known special cases. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 42–44, 1999.

Magnetoelectric Interactions in Bi-Anisotropic Media

Classification of bi-anisotropic media based on the structure of magnetoelectric coupling dyadics is proposed. It appears that the most general bi-anisotropic media can be modeled as composites of only a few basic idealized elements: for reciprocal materials, these elements are uniaxial helices and "hats," and in the case of non-reciprocal media, the fundamental particles are Tellegen elements (coupled electric and magnetic dipoles). In particular, it is shown that some composites with omega-shaped conductive inclusions embedded in an isotropic dielectric matrix can be considered as media with equivalent phantom chiral particles. Also, the mechanism is analyzed of the bi-anisotropic material based on magnetostatic-wave resonators.

Resonant Mode Characteristics of a Magnetostatic Resonator in Yttrium Iron Garnet (YIG) Films

In this paper, the performance of a magnetostatic surface wave straight edge resonator (MSSW-SER) is extensively studied, including the mode field distribution, the unloaded quality factor of the fundamental mode and coupling to the external circuit. Measurement of the magnetic field distribution on a MSSW-SER is found to be useful for identifying the mode number. The unloaded Q-value of the fundamental mode, which includes magnetic loss and conductor loss, and also the external Q are measured to give design data for tunable band-pass filters. Moreover, an equivalent circuit is set up to analyze the external Q, and verified by experiment. Under higher power excitation, a novel performance of the MSSW-SER is found in YIG films, that is, the resonant frequency shifts to the lower side and the unloaded quality factor tends to decrease. These phenomena caused by the nonlinear effect of a MSSW-SER are analyzed by means of the nonlinear MSSW dispersion relation. The above methods can be easily extended to study two other modes, magnetostatic forward volume wave (MSFVW) and magnetostatic backward volume wave (MSBVW) resonators.

On the technology of making chiral and bianisotropic waveguides for microwave propagation

We introduce an idea for a novel class of artificial materials suitable for chiral and bianisotropic waveguide structures. Fabrication of such waveguides can be achieved using modern planar technology. Chiral and bianisotropic waveguides described in this article are based on a composition of magnetostatic wave (MSW) resonators. Because of the small sizes of MSW resonators the concentration of the particles may be very high. The resonance frequency of MSW resonators may be tuned via a bias magnetic field. Therefore, we can develop a method of achieving chirality control. © 1996 John Wiley & Sons, Inc.

On the technology of making chiral and bianisotropic waveguides for microwave propagation

We introduce an idea for a novel class of artificial materials suitable for chiral and bianisotropic waveguide structures. Fabrication of such waveguides can be achieved using modern planar technology. Chiral and bianisotropic waveguides described in this article are based on a composition of magnetostatic wave (MSW) resonators. Because of the small sizes of MSW resonators the concentration of the particles may be very high. The resonance frequency of MSW resonators may be tuned via a bias magnetic field. Therefore, we can develop a method of achieving chirality control. © 1996 John Wiley & Sons, Inc.

Temperature drift of a magnetic resonance field for a rectangular Bi,Ga substituted YIG film

This paper aims at studying a drift of magnetic resonance field versus temperature for the Bi,Ga substituted YIG film in a rectangular shape. The experimental and theoretical results show that the resonance magnetic field for the rectangular Bi,Ga substituted YIG film having a proper growth induced anisotropy changes parabolically with ambient temperatures and the turnover temperature of the parabolic curve is affected by the aspect ratio of the sample. This size effect can be used as a turnover temperature trimming procedure of the Bi,Ga substituted YIG films for magnetostatic forward volume wave (MSFVW) resonator elements which have reliable resonance frequency-temperature characteristics.

Phase-Shift Control of Resonant Frequencies of Magnetostatic Wave Resonators

We discuss a possible technique to control the resonant frequencies of a straight-edge magnetostatic wave (MSW) resonator without changing the external applied magnetic field and the circuit parameters of a feedback load circuit. The method is to use two additional microstrip electrodes at the edges of the resonator and two varactor diodes connected in series. Upon varying the bias voltages to the varactor diodes, the input admittance at the center electrode can be changed. Theoretical investigation reveals that very large resonant frequency shifts can be obtained by changing only the bias voltage change to the varactor diodes, which may be useful in mobile telephone applications in the gigaherz frequency range.

Magnetostatic wave resonators using microstrip disk

The authors propose a magnetostatic wave resonator using yttrium-iron-garnet (YIG) film with a microstrip disk. Assuming a magnetic wall at the edge of the disk, a dispersion relation is derived and solved numerically to obtain the resonant frequency. Resonant mode charts are given for various parameters of resonator. The quality factor is also given as a function of the resonator dimensions. Resonant characteristics are confirmed experimentally using 40- mu m- and 13.5- mu m-thick YIG films with 5-mm-diameter strip disk at S band.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Planar resonator and integrated oscillator using magnetostatic waves

A simple planar resonator using a magnetostatic wave (MSW) excited by aluminum finger electrodes with two bonding pads was realized on YIG/GGG (yttrium-iron-garnet film on a gadolinium-gallium-garnet crystal) substrate with two reflection edges. The tunable MSW resonator chip (2 mmx5 mm) exhibited a sharp notch filter response, as deep as 20-35 dB, and a high loaded Q up to 2000, which was tunable over the microwave frequency range from 2 to 4 GHz. A small tunable oscillator (8 cm(3)) was experimentally demonstrated using the MSW planar resonator and a silicon bipolar transistor integrated on a ceramic microwave circuit substrate. Microwave oscillation with spectral purity, at the same level as that of YIG sphere technology, was observed at 3 GHz. The experimental results indicate the technical areas where improvement must be made to realize a practical oscillator configuration.

Mode-selective magnetostatic wave resonator

A novel magnetostatic wave (MSW) resonator, based on yttrium iron garnet (YIG) epilayers, which has been designed for selective excitation of a desired higher-order resonant mode and contemporary suppression of all the other modes, is presented.

Analysis of microstrip‐magnetostatic wave resonators

AbstractThis paper analyzes a microstrip‐type magnetostatic wave resonator made of a YIG film loaded with a metal disk. First, based on a simple model consisting of a magnetic wall at the edge of the disk, the relationship between the resonant frequency and the aspect ratio and the Q value was investigated. Next, a more realistic model is set up and analyzed by the mode matching technique. The relationship between various resonator parameters and the energy trapping situation of the magnetostatic wave in the disk is found. Also the distribution of the RF magnetization in the disk is presented.

Loop transducer matching for low insertion loss magnetostatic surface wave resonator

In this paper we describe the matching of a loop transducer to significantly reduce the insertion loss and to improve the off-resonance rejection of a magnetostatic surface wave resonator.

Single and coupled MSW resonators for microwave channelizers

Magnetostatic-wave (MSW) resonators using epitaxial single-crystal yttrium iron garnet (YIG) films have been integrated to form a channelizer operating in the microwave frequency range. The microwave signals are coupled to and from the resonators using microstrip structures. This approach to frequency sorting has the advantage of relatively low insertion loss (less than 6 dB for single resonators), and only a uniform bias magnetic field is needed. This approach has been used to enhance the bandwidth and improve the filter response of each channel. Channel 3-dB bandwidths were increased from 4-5 MHz (for single-resonator channels) to more than 10 MHz by implementing coupled resonators. Experimental results describing the characteristics of single and coupled MSW resonators are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Tunable Microwave Resonators Using Magnetostatic Wave in YIG Films

The purpose of this paper is to review the status of magnetostatic wave (MSW) resonators and to describe, in detail. the theory of operation of the recently developed straight-edge resonators. These resonators are based on magnetostatic waves propagating in high Q cavities fabricated in thin ferrimagnetic films. The resonance frequency of these resonators can be tuned via a bias magnetic field. The theory of propagation of magnetostatic wave devices in periodic arrays will be briefly described followed by a detailed overview of the different configurations for MSW resonators. Three distinct classes of resonators will be discussed 1) resonators based on array reflectors (deposited metals and etched grooves) will be described in detail; 2) guided-wave ring resonators will be discussed; and 3) the theory of operation and design criteria for the straight-edge resonators will be described. Each class will be evaluated, pointing out the advantages and drawbacks, and whenever applicable, the power handling properties and the phase noise performance will be given.