Composite Resonator Research Articles

Dual electric and magnetic frequency tuning of coupled oscillations in a composite magnetodielectric resonator

The possibility of dual magnetic and electric tuning of resonance frequencies of the electrodynamic structure consisting of dielectric resonator and the epitaxial film of Yittrium-Iron Garnet (YIG)- lead zirconate titanate (LZT) heterostructure has been shown. The coupled electromagnetic-andspin oscillations of dielectric resonator and epitaxial YIG film were theoretically and experimentally investigated. The experiments revealed the possibility of implementing the electric frequency tuning of coupled oscillations of a composite magnetodielectric resonator. This possibility is determined by induced elastic stresses in the epitaxial YIG film. A theoretical model is proposed for calculating the frequency shift of coupled oscillations caused by the electric field applied to the piezodielectric layer. It is shown that the basic Q-factor of composite resonator and the range of electric frequency tuning of hybrid oscillations increase with the reduction of the magnetic bias field.

Intrinsically switchable thin film bulk acoustic wave resonators

The concept of the frequency switching in the composite bulk acoustic wave (BAW) resonators based on the thin films of paraelectric phase ferroelectrics is demonstrated experimentally. The composite BAW resonators based on the Ba0.25Sr0.75TiO3/SrRuO3/Ba0.25Sr0.75TiO3 multilayer structure are fabricated and characterized. It is shown that the resonance frequency of the BAW resonators can be switched more than two times (from 3.6 GHz to 7.7 GHz) by changing polarity of the 5 V dc bias voltage at one of the ferroelectric layers. The composite BAW resonators performance is analyzed using the theory of the dc field induced piezoelectric effect in the paraelectric phase ferroelectrics.

SIW 구조를 이용한 저 위상잡음 전압 제어 평판형 복합공진기 발진기 설계

본 논문에서는 저 위상잡음을 갖는 전압 제어 평판형 복합공진기 발진기(Vt-PCRO: Voltage-tuned Planar Composite Resonator Oscillator)를 설계, 제작하였다. 설계된 발진기는 공진기, 2개의 위상천이기, 증폭기로 구성된다. 공진기는 dual mode SIW(Substrate Integrated Waveguide) 공진기를 이용하여 구성하였으며, 약 40 nsec의 높은 군지연을 갖도록 하였다. 2개의 위상천이기 중(PS1, PS2: Phase Shifter 1 및 Phase Shifter 2) PS1은 <TEX>$360^{\circ}$</TEX>의 위상천이량을 가지며, 제작된 발진기의 전송선로 길이에 관계없이 개루프 이득(open loop gain) 발진조건을 만족하도록 한다. PS2는 약 <TEX>$70^{\circ}$</TEX>의 위상천이량을 가지며 발진 주파수 조정용으로 사용된다. 증폭기는 제작 시 발생한 큰 삽입손실의 문제를 보완하기 위해 2단으로 구성하였다. 개루프 이득 측정을 통해 발진 조건을 만족하는 PS1의 전압을 측정한 뒤, 폐루프로 구성하여 발진기를 구현하였다. 발진기 측정 결과, 5.345 GHz의 발진 주파수에서, 위상 잡음은 100 kHz offset 주파수에서 -130.5 dBc/Hz를 얻었다. 이때 출력 전력은 약 3.5 dBm, 전기적 주파수 조정 범위는 0~10 V의 조정 전압에서 약 4.2 MHz를 보였다. In this paper, we present a design and implementation of a Voltage-tuned Planar Composite Resonator Oscillator(Vt-PCRO) with a low phase noise. The designed Vt-PCRO is composed of a resonator, two phase shifters, and an amplifier. The resonator is designed using a dual mode SIW(Substrate Integrated Waveguide) resonator and has a group delay of about 40 nsec. Of the two phase shifters (PS1 and PS2), PS1 with a phase shift of <TEX>$360^{\circ}$</TEX> is used for the open loop gain to satisfy oscillation condition without regard to the electrical lengths of the employed microstrip lines in the loop. PS2 with a phase shift of about <TEX>$70^{\circ}$</TEX> is used to tune oscillation frequency. The amplifier is constructed using two stages to compensate for the loss of the open loop. Through the measurement of the open loop gain, the tune voltage of the PS1 can be set to satisfy the oscillation condition and the loop is then closed to form the oscillator. The oscillator with a oscillation frequency of 5.345 GHz shows a phase noise of -130.5 dBc/Hz at 100 kHz frequency offset. The oscillation power and the electrical frequency tuning range is about 3.5 dBm and about 4.2 MHz for a tuning voltage of 0~10 V, respectively.

Method for digital measurement of phase-frequency characteristics for a fixed-length ultrasonic spectrometer

One of the most accurate methods for measuring the compressibility of liquids is resonance measurement of sound velocity in a fixed-length interferometer. This method combines high sensitivity, accuracy, and small sample volume of the test liquid. The measuring principle is to study the resonance properties of a composite resonator that contains a test liquid sample. Ealier, the phase-locked loop (PLL) scheme was used for this. In this paper, we propose an alternative measurement scheme based on digital analysis of harmonic signals, describe the implementation of this scheme using commercially available data acquisition modules, and give examples of test measurements with accuracy evaluations of the results.

The effect of composite resonances on Higgs decay into two photons

In scenarios of strongly coupled electroweak symmetry breaking, heavy composite particles of different spin and parity may arise and cause observable effects on signals that appear at loop levels. The recently observed process of Higgs to $\gamma \gamma$ at the LHC is one of such signals. We study the new constraints that are imposed on composite models from $H\to \gamma\gamma$, together with the existing constraints from the high precision electroweak tests. We use an effective chiral Lagrangian to describe the effective theory that contains the Standard Model spectrum and the extra composites below the electroweak scale. Considering the effective theory cutoff at $\Lambda = 4\pi v \sim 3 $ TeV, consistency with the $T$ and $S$ parameters and the newly observed $H\to \gamma\gamma$ can be found for a rather restricted range of masses of vector and axial-vector composites from $1.5$ TeV to $1.7$ TeV and $1.8$ TeV to $1.9$ TeV, respectively, and only provided a non-standard kinetic mixing between the $W^{3}$ and $B^{0}$ fields is included.

Higgs-Z-photon coupling from effect of composite resonances

We explore the Higgs-Z-photon coupling in the Minimal Composite Higgs Model with vector and axial resonances. The electroweak precision measurement, i.e. S and T, is estimated for this model. We calculate the signal strength for Higgs decay into Z-photon and notable enhancement is found in certain EWPT allowed parameter region.

Intrinsically switchable, high-Q ferroelectric-on-silicon composite film bulk acoustic resonators

This paper presents a voltage-controlled, highquality factor (Q) composite thin-film bulk acoustic resonator (FBAR) at 1.28 GHz. The composite FBAR consists of a thin layer of barium strontium titanate (BST) that is sandwiched between two electrodes deposited on a silicon-on-insulator (SOI) wafer. The BST layer, which has a strong electrostrictive effect, is used for electromechanical transduction by means of its voltage-induced piezoelectricity. The silicon layer, with its low mechanical loss, increases the Q of the resonator. The composite FBAR presented here exhibits Qs exceeding 800 with a resonance frequency and Q product (f × Q) of 1026 GHz.

Temperature characteristics of magnetoelectric interaction in langatate-ferromagnet composite resonators

Magnetoelectric interaction in a layered langatate-hysteretic ferromagnet structure is observed with no bias magnetic field applied. The temperature characteristics of interaction are determined mainly by the properties of the ferromagnetic layer. Raising the temperature weakens the coupling between layers and lowers the efficiency of interaction.

Enhancement of ultrahigh-frequency vibration of an Au/Si3N4 composite resonator with picosecond ultrasound

We found that the second through-thickness vibration mode of a gold/silicon-nitride composite thin film is selectively excited by picosecond ultrasound with high efficiency by controlling the thickness ratio. Its mechanical vibration frequency exceeds 50 GHz, making it promising for mass detectors with ultrahigh sensitivity. We developed a theoretical model based on the strain-energy ratio between gold and silicon-nitride layers and successfully explained the enhancement of the second vibration mode. A sensor chip was applied to detect immobilized proteins through the change in resonance frequency.

Higgs couplings in composite models

We study Higgs couplings in the composite Higgs model based on the coset $SO(5)/SO(4)$. We show that the couplings to gluons and photons are insensitive to the elementary-composite mixings and thus not affected by light fermionic resonances. Moreover, at leading order in the mixings the Higgs couplings to tops and gluons, when normalized to the Standard Model (SM), are equal. These properties are shown to be direct consequences of the Goldstone symmetry, of the partial compositeness structure and of the assumption of $CP$ invariance. In particular, they are independent of the details of the elementary-composite couplings, and they are also insensitive to derivative interactions of the Higgs with the composite resonances. We support our conclusions with an explicit construction where the SM fermions are embedded in the 14-dimensional representation of $SO(5)$.

A high selectivity quad-band bandpass filter based on hybrid-coupled microstrip/slotline quad-mode resonator

A sharp-rejection and high-isolation quad-band bandpass filter with ellipse response using hybrid microstrip/slotline quad-mode resonator is proposed in this paper. The presented composite quad-mode resonator consists of a narrow L-shaped slot in the ground plane and a broadside microstrip L-shaped structure loaded by the two orthogonal narrow-stripline stubs. The dual-metal-plane resonator on a single substrate is employed to obtain a quad-frequency response. Based on this quad-mode resonator, a filter with four passbands centering at 3.86, 6.93, 10.13, and 12.58 GHz is designed, fabricated, and measured. Simulated results from the full-wave electromagnetic software and measured results show a good agreement. The measured inter-band isolations among the quad-frequency passbands with multi-transmission zeros are greater than 22 dB.

Thermoelastic Damping in Laminated Composite Circular Microplate Resonators

High quality factor is an essential requirement in the design of microsensors used for sensing and communications applications. In previous works, some analytical models have been developed for thermoelastic damping in monolayer structure and multi-layered beam. This paper proposes a new model for thermoelastic damping in symmetric, three-layered, laminated, microplate resonators. Our approach utilizes the analytical framework developed by Bishop and Kinra and Gaussian curvature. The effect of volume fraction is numerically calculated. It is noticed that the maximum damping is determined by volume fraction, which is independent of the single layer thickness. The thinner plate is, the higher frequency is that reach the maximum damping.

Yttrium Iron Garnet: Properties and Applications Review

Due to a fast progress in the development of communication systems, the dielectric and magnetic ceramics (ferrites) have become attractive to be used in devices. Although the ferrites of the spinel type were the first material to be used in the microwave range, garnets have smaller dielectric losses and, therefore, are chosen for many applications. High demands for modern electric applications in magnetic materials results in new techniques and products being permanently studied and researched, with a consequent appearance of new solutions for a wide applications series. This work presents the study of the ferrimagnetic composite, constituted by Y3Fe5O12 (YIG) and Gd3Fe5O12 (GdIG) phases, through solid state synthetic route and submitted to high-energy mechanical milling. Additionally, experiments were made in order to evaluate the electric and magnetic behavior of the composites at radio frequency and microwave range and then later suggest an adequate technological application. The composites were efficient as ferrite resonator antennas (FRAs) and microstrip antennas (thick films deposited on metalized surface alumina substrate by screen-printing technique), in the microwave frequency range. The experiments with FRAs showed satisfactory results due to the control of the antennas radiation characteristics and their tuning by the use of an external magnetic field. The composite resonators studied in this work can be important to the development of a third generation (3G) wideband antennas to cell phones and other wireless products.

The Q factor of resonators containing transmission line sections and several capacitors

Relationships are obtained for determination of unloaded Q factor of microwave resonators tuned by several capacitors. New concepts are proposed for the variation of the Q factor of resonators during their tuning. It is proved that the unloaded Q factor of a composite resonator does not depend on the number of tunable capacitors with equal Q factor.

Impedance of DC-bias-controlled composite FBARs

A closed-form analytic formula is derived for composite resonators consisting of two layers of paraelectricphase ferroelectrics. It is used to analyze the properties of these resonators. Under an applied dc electric field, the layers exhibit an induced piezoelectric effect. The signs of the induced piezoelectric coefficients may be changed by changing the polarity of the dc voltages applied to the layers. In the case of a composite in which the layers have similar thicknesses, changing the sign of the piezoelectric coefficient causes a switching between the resonant frequencies of the first and second harmonics. In the case in which one of the layers is substantially thinner, changing the sign of the piezoelectric coefficient causes switching of the resonant frequency of the first harmonic between two values. In both cases, a continuous change in the dc bias voltage causes continuous changes in the resonant frequencies.

Temperature behavior of magnetoelectric interaction in composite PZT-nickel disk resonators

The temperature dependences of the characteristics of magnetoelectric interaction in composite disk resonators made up of Ni and PZT layers are studied. Measurements are taken on monolithic resonators, prepared by electrolytic deposition of Ni on PZT, and resonators prepared by gluing Ni and PZT layers. In the temperature interval 220–380 K, the frequency of the monolithic resonators changes by up to 16% and that of the glued resonators, by 4.5%. It is shown that the efficiency of magnetoelectric interaction declines with increasing temperature, since (i) the piezoelectric modulus and piezomagnetic coefficient of the layers vary, (ii) the PZT permittivity rises, and (iii) the layer-to-layer adhesion weakens due to softening of the glue. The results can be used in developing techniques for stabilizing the magnetoelectric interaction characteristics of composite structures.

Is Magnetic Resonance Imaging Reliable in Predicting Clinical Outcome After Articular Cartilage Repair of the Knee?

Background: While MRI can provide a detailed morphological evaluation after articular cartilage repair, its additional value in determining clinical outcome has yet to be determined. Purpose: To evaluate the correlation between MRI and clinical outcome after cartilage repair and to identify parameters that are most important in determining clinical outcome. Study Design: Systematic review and meta-analysis. Methods: A systematic search was performed in Embase, MEDLINE, and the Cochrane Collaboration. Articles were screened for relevance and appraised for quality. Guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) Statement were used. Chi-square tests were performed to find variables that could determine correlation between clinical and radiological parameters. Results: A total of 32 articles (total number of patients, 1019) were included. A majority (81%) were case series or cohort studies that used similar standardized MRI techniques. The mean Coleman score was 63 (range, 42-96). For the majority of MRI parameters, limited or no correlation was found. Nine studies (28%) found a correlation between clinical outcome and the composite magnetic resonance observation of cartilage repair tissue (MOCART) or Henderson score and 7 (22%) with defect fill. In 5 studies, a weak to moderate correlation was found between clinical outcome and the T2 index (mean Pearson coefficient r = .53). Conclusion: Strong evidence to determine whether morphological MRI is reliable in predicting clinical outcome after cartilage repair is lacking. Future research aiming specifically at clinical sensitivity of advanced morphological and biochemical MRI techniques after articular cartilage repair could be of great importance to the field.

DUAL AND TRI-BAND-NOTCHED ULTRAWIDEBAND (UWB) ANTENNAS USING COMPACT COMPOSITE RESONATORS

An ultra-wideband (UWB) antenna with triple band- notched characteristics is presented in this paper. The triple-notched bands (5.15{5.35GHz and 5.725{5.825GHz for WLAN, 7.9{8.395GHz for X-band) are achieved by using only one novel composite resonator with multiple resonant characteristics. The resonator is placed on the back surface of the substrate and connected to the radiation patch through one via-hole. An equivalent circuit model is built for analyzing the band-notched characteristics. Moreover, the notched bands can be adjusted independently, and the resonator structure is very compact.

Calculation of the spectral characteristics of an acoustic resonator containing layered multiferroic structure

Multifrequency composite acoustic resonators for bulk acoustic waves with piezoelectric and ferromagnetic layers are studied. The structures with a thick ferrite substrate layer and a thin ferrite film on a nonmagnetic dielectric substrate and multilayer structures are considered. A thin piezoelectric layer that is placed between two metal electrodes serves as a transducer. Analytical expressions for the input electric impedance of the electroacoustic transducer are derived for various structures under study in the presence of the transverse control magnetic field. The amplitude-frequency and phase-frequency characteristics of the cavity are numerically calculated. The resonance frequency can be controlled in the interval ±1.2 MHz (about 25% of the intermode distance) due to variations in the magnetic field.

Mechanism of electric frequency tuning in composite resonators based on epitaxial ferrite films

A planar bilayer structure comprising an epitaxial film of yttrium iron garnet (YIG) ferrite film on a lead zirconate titanate (PZT) piezoelectric plate has been studied. It is shown both theoretically and experimentally that electric tuning of the resonant frequency is possible due to elastic-stress-induced variations of the field of uniaxial first-order anisotropy, while the field of uniaxial second-order anisotropy changes to a much lower degree. It is established that gluing of the ferrite and metal-coated piezoelectric layers rather insignificantly increases losses in the magnetostatic resonator.