Top PDF High frequency oscillator comprising cointegrated thin film resonator and active device

High frequency oscillator comprising cointegrated thin film resonator and active device

High frequency oscillator comprising cointegrated thin film resonator and active device

A process for forming a cointegrated oscillator the ampli?er and the thin ?lm resonator to function including active devices comprising an ampli?er and a in circuit interrelationship as [r]

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A film bulk acoustic resonator oscillator based humidity sensor with graphene oxide as the sensitive layer

A film bulk acoustic resonator oscillator based humidity sensor with graphene oxide as the sensitive layer

Use of a sensitivity sensing layer could improve the performance of a sensor[6]. To develop the high sensitivity FBAR oscillator humidity sensors, a GO layer was used as the sensing layer in this work. The GO solution was purchased from C6G6 Company, with a concentration of 14.6 mg/ml. The solution was diluted 100 times using DI water and used for thin GO film deposition on the surface of FBAR devices. Before the GO film deposition, the FBAR device was rinsed with ethanol and DI water, then dried using nitrogen gas and baked in an oven for 2 hours at 60 o C. The GO film was dip coated on the surface of the devices by placing the device horizontally into the diluted solution for a while, and then pulled out. The thickness of GO layer can be controlled by varying the deposition time (from 30 to 90 sec for different samples). GO is composed of hydrophobic carbon six-membered rings layer and a large number of hydrophilic groups (such as hydroxyl, carboxyl) bonded to carbon layer, the characteristics of the GO material was reported previously [16]. After GO film deposition, the FBAR was wire-bonded to the oscillator board and placed in the test chamber for humidity sensing. Two oscillators were placed into a test chamber (volume about 160 ml), one with a bare surface FBAR as a reference and one with a GO-coated FBAR for sensing. Humidity in the test chamber was controlled by changing the ratio of dry and wetted nitrogen, as shown in figure 3(d). The FPGA based frequency counter (shown in figure 3(e)) was connected to the oscillator to measure the frequency shift, and a PC was connected to the frequency counter to record the frequency shift. Figure 3(f) shows the frequency jitter (noise) of the sensor in time domain obtained by the frequency counter with a value about 1 kHz. Additional information for sensing experiments could be found from our previous publication [16].
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A film bulk acoustic resonator oscillator based humidity sensor with graphene oxide as the sensitive layer

A film bulk acoustic resonator oscillator based humidity sensor with graphene oxide as the sensitive layer

Use of a sensitivity sensing layer could improve the performance of a sensor[6]. To develop the high sensitivity FBAR oscillator humidity sensors, a GO layer was used as the sensing layer in this work. The GO solution was purchased from C6G6 Company, with a concentration of 14.6 mg/ml. The solution was diluted 100 times using DI water and used for thin GO film deposition on the surface of FBAR devices. Before the GO film deposition, the FBAR device was rinsed with ethanol and DI water, then dried using nitrogen gas and baked in an oven for 2 hours at 60 o C. The GO film was dip coated on the surface of the devices by placing the device horizontally into the diluted solution for a while, and then pulled out. The thickness of GO layer can be controlled by varying the deposition time (from 30 to 90 sec for different samples). GO is composed of hydrophobic carbon six-membered rings layer and a large number of hydrophilic groups (such as hydroxyl, carboxyl) bonded to carbon layer, the characteristics of the GO material was reported previously [16]. After GO film deposition, the FBAR was wire-bonded to the oscillator board and placed in the test chamber for humidity sensing. Two oscillators were placed into a test chamber (volume about 160 ml), one with a bare surface FBAR as a reference and one with a GO-coated FBAR for sensing. Humidity in the test chamber was controlled by changing the ratio of dry and wetted nitrogen, as shown in figure 3(d). The FPGA based frequency counter (shown in figure 3(e)) was connected to the oscillator to measure the frequency shift, and a PC was connected to the frequency counter to record the frequency shift. Figure 3(f) shows the frequency jitter (noise) of the sensor in time domain obtained by the frequency counter with a value about 1 kHz. Additional information for sensing experiments could be found from our previous publication [16].
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A Push-Push Oscillator Array Using Resonator Type Coupling Circuits

A Push-Push Oscillator Array Using Resonator Type Coupling Circuits

between the adjacent oscillators is achieved by the coupling circuit. The phase differences between the output signals are controlled by the coupling circuit as well. Fig. 1(b) shows the structure of the push- push oscillator used for the oscillator and the connection of the oscillators and the coupling circuits. The push-push oscillator consists of two sub-oscillators, that is a negative resistance circuit ( − r), and a microstrip ring resonator that also plays a role of a power combiner. The active devices used for the sub-oscillators are HEMT. These two sub-oscillators generate the fundamental frequency signals with the same amplitude and 180 degrees phase difference due to the resonant field of the ring resonator. Consequently, the signals of the sub-oscillators are represented by (1) and (2).
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High Frequency Thick Film BST Ferroelectric Phase Shifter

High Frequency Thick Film BST Ferroelectric Phase Shifter

This paper discusses the performance of a thick-film ferroelectric phase shifter at high frequency. The phase shifter is fabricated from Barium Strontium Titanate (BST) thick-films on alumina substrates using a screen-printing method, and the electrodes are patterned using direct gravure-printing. We have achieved down to 40 µm gaps between electrodes using this method. Comparison between the theoretical response and experiment results will be presented. The extracted dielectric constants of the BST material using this phase shifter is also be presented here.

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The impact of high frequency high current perturbations on film formation at the negative electrode electrolyte interface

The impact of high frequency high current perturbations on film formation at the negative electrode electrolyte interface

Cell surface temperature measurements presented in Fig. 9 suggest that heat generation within a cell is related to the AC excitation frequency. Equation (18) proposes four sources of heat generation, namely resistive dissipation, electrochemical reac- tions, chemical reactions and the heat of mixing. Impedance spectroscopy results presented in Fig. 10 show that resistive dissipation within the cell is frequency dependant. In the next subsection, a reference electrode cell potential relaxation experi- ment is employed to investigate the heat of mixing. Cell potential relaxation is indicative of ion concentration at the electrode- electrolyte boundary, such that a relatively longer relaxation time represents higher ion concentration. If there is a signi fi cant difference in ion concertation at the electrode-electrolyte bound- ary when different excitation frequencies are applied, this will reveal an underlying frequency dependence of the heat of mixing. Furthermore, assuming fi rst-order solvent decomposition kinetics, a higher reactant concentration at the negative electrode boundary will, itself, facilitate an increased rate of SEI growth [29]. 4.5. Cell Potential Relaxation Experiment Results
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Electronic device fabrication from thin film diamond: Surface preparation, patterning, metallisation and characterisation

Electronic device fabrication from thin film diamond: Surface preparation, patterning, metallisation and characterisation

Investigation of excimer laser processing of diamond films of varying quality has been carried out in detail and demonstrates the capability of at least micron-sized resolution patterning reproducible over an area of 2 mm x 1 mm when used in the maskless mode of projection patterning. Clean surfaces are achievable by the employment of this method. Various concerns, however, have been raised from the results of this study: firstly the nature of the rough surface intrinsic in as-deposited polycrystalline films may be reflected in the final etched surface depending on the quality of the material. This effect though, will be alleviated by the prior application of polishing techniques; such polishing will be required as the development of more complicated electronic device structures are encountered, and may be conveniently based on excimer lasers. In addition, the cross- sectional variation in material quality will demand strict control of laser parameters if either critical thicknesses, or the removal of diamond material to a heterogeneous substrate is required. The observation of non-vertical sidewalls is of immediate concern and prevents structures with high aspect ratios being developed for the application of diamond in micro-electromechanical systems. Although it has been demonstrated here for the first time that wall angles depend on the laser energy intensity, a value of 25° still exists in the structures delineated. Nevertheless, this study is the first report to the author's knowledge [Chan et al, 1995] of the formation of free-standing diamond microstructures from a etching-based technique that may be superior in terms of throughput and quality of finish to more established etching approaches such as RIE which requires masking processes, and also to the "direct-writing" mode of focused laser beam scanning.
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A Low Cost RF Oscillator Incorporating a Folded Parallel Coupled Resonator

A Low Cost RF Oscillator Incorporating a Folded Parallel Coupled Resonator

The most commonly employed resonator is the quarter-wavelength resonator in which one end is grounded and the other end is open as shown in Fig. 1(a) [11]. The current is maximum at the grounded end and minimum at the open end while the voltage is minimum at the grounded end and maximum at the open end [12]. This type of resonator allows construction of a compact oscillator but it suffers from low Q value, especially if used on FR4 for low cost solutions. The losses are primarily attributed to dielectric losses which occur near the open end of the resonator. If the resonator length is reduced and resonance is achieved with capacitive loading, then the dielectric losses are reduced and a higher-Q is achieved [12]. The process involves addition of capacitors in parallel to the resonator. This lowers the resonant frequency, which allows the length of the resonator to be reduced to achieve resonance at the desired frequency. Such techniques of capacitively compensating the resonator do result in higher level of performance but at the same time use of lumped components adds to the complexity of design and component count, thereby increasing the production cost.
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High frequency surface acoustic wave resonator based sensor for particulate matter detection

High frequency surface acoustic wave resonator based sensor for particulate matter detection

The bondwire is plunged into a bottle containing micrometre-sized particle powder (with known particle diameter) so that some particles adhere on to it due to the attractive interparticle forces that exist in micron and sub-micron sized particles [23]. With the aid of the linear translation stage, this bondwire (containing the adherent particles) is then gently rubbed onto the sensor surface, allowing the particles to fall on to the sensor surface. The deposition of this particle mass onto the sensor surface produces a shift in frequency at the SAWR oscillator output. The entire deposition process was visually monitored in real time through a digital microscope, to guide the placement of particulate mass on to the sensor surface. In addition, a photomicrograph of the sensor surface with the deposited particles was also captured, which was used to count the number of particles deposited onto the sensing area. Figure 6[B] shows the photograph of gold particles with diameter of < 1 µm deposited on the sensing area of the SAWR particle sensor. The scanning electron microscopic images of these gold particles are shown in Figure 6[C]. The sensor unit is placed inside an environmental chamber to ensure ambient temperature stability, to avoid both air current effects and the deposition of any foreign material on the sensor within the laboratory environment.
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High Q Fano Resonance in Terahertz Frequency Based on an Asymmetric Metamaterial Resonator

High Q Fano Resonance in Terahertz Frequency Based on an Asymmetric Metamaterial Resonator

A large amount of researches indicate that breaching the symmetry of a structure may induce an asymmetric Fano line shape [17, 18, 35–37]. Based on this concept, we de- sign this four-strip metamaterial displayed in Fig. 1, where strip 2 is set to realize a symmetry breaking. Fig- ure 1a shows the three-dimensional diagram of the pro- posed metamaterial. Figure 1b, c respectively shows the side view and top view of the structure unit. The metal- lic four-strip resonators are placed on the top of an ideal dielectric substrate whose real part of refractive index is 1.5 and imaginary part is 0. In reality, this dielectric ma- terial is corresponding to silica. That is to say, the sub- strate is lossless in terahertz region. We choose Au with conductivity σ = 4.09 × 10 7 S/m to form the metallic pla- nar resonator whose thickness is 0.2 μm. The repeat period is P x = P y = 180 μm. Three parallel strips (1, 2,
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Thermoelectric Power Generation Characteristics of a Thin Film Device Processed by the Flip Chip Bonding of Bi2Te3 and Sb2Te3 Thin Film Legs Using an Anisotropic Conductive Adhesive

Thermoelectric Power Generation Characteristics of a Thin Film Device Processed by the Flip Chip Bonding of Bi2Te3 and Sb2Te3 Thin Film Legs Using an Anisotropic Conductive Adhesive

point-probe method, and the power factor (P) was evaluated using the relation P = ¡ 2 /μ. Power generation characteristics, such as the output voltage and the output power, of the thin- fi lm device were measured by placing the device between an electrically heated copper heat source and a water-cooled copper heat sink. The apparent temperature difference "T applied across the top and bottom substrate of the thin-film device was measured using thin k-type thermocouples placed between the thin-film device and the heat source/sink surfaces.
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Thin film diamond: electronic devices for high temperature, high power and high radiation applications

Thin film diamond: electronic devices for high temperature, high power and high radiation applications

Single crystal diamond has a unique combination of electronic and material properties that give rise to a wide range of potential applications. However, its extreme cost, limited surface area and variability in properties have prevented it from achieving many of these potential goals. The carrier concentration in a semiconductor material is affected by the donor and acceptor concentrations; the impurities and defects in natural diamond are thought to be the reason for the compensation observed [3.1]. The development of a high pressure, high temperature (HPHT) technique for diamond synthesis [3.2] provided the first opportunity for control of the defects. However, impurities arising from the catalysts that are essential to the economic production of synthetic diamond crystals provided another source of compensation. Furthermore, synthesised crystals are small (of the order of millimetres), expensive and only available in the form of bulk crystals, as a consequence they have only found applications as heat sinks. However, in the 1960s, Eversole [3.3] and Angus et al. [3.4] demonstrated that chemical vapour deposition (which operates at conditions that are low pressure and low temperature) could be utilised to increase the mass of diamond grit and that some fraction of that mass increase was diamond. However, the low growth rates coupled with the co­ deposition of significant amounts of graphite retarded any advancement or further interest in homoepitaxy (the epitaxial^ growth of a material on a substrate of identical material). The conditions used for the CVD growth of diamond are in a pressure-temperature regime where diamond is thermodynamically unstable with respect to graphite, i.e. at pressures and temperatures less than atmosphere and 1373K respectively; the energy difference between the two allotropes is only 0.7 kcal/mol [3.5, 3.6] and it is only by virtue of a significant activation barrier that diamond is prevented from transforming into graphite. Consequently, graphite formation will always occur in the CVD growth of diamond; Angus et al. [3.4] observed that regardless of any changes made in the temperature or pressure to conditions favourable for diamond, the growth of graphite was even more favourable. This paradox remained until intensive work carried out by Deryagin et al. [3.7] discovered the critical role of atomic hydrogen in achieving metastable diamond growth as a selective etchant for graphite but not diamond; this enabled diamond to be grown even on non-diamond substrates. The potential for a practical diamond growth technology became apparent with the production of diamond
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Thin film electroluminescence

Thin film electroluminescence

With the dielectric layer across each would given charge value, the therefore be the total device threshold voltage would be around 1 a 200 nm voltage dielectric layer drop for this devi[r]

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Thermoelectric Thin Film Device of Cross Plane Configuration Processed by Electrodeposition and Flip Chip Bonding

Thermoelectric Thin Film Device of Cross Plane Configuration Processed by Electrodeposition and Flip Chip Bonding

difficult to control the coplanarity of the electrodeposited Bi­ Te and Sb­Te leg heights. Also, the surface roughness as well as the flatness of the electrodeposited thin film legs was very critical for flip-chip bonding of the top-substrate electrode pads to the thin-film legs. In order to overcome these issues, we electrodeposited the Bi­Te and Sb­Te thin film legs fully to overflow, as illustrated in Figs. 1(c) and 1(e). Then mechanical polishing was done on the overgrown Bi­Te and Sb­Te thin film legs in the photoresist template to obtain smooth and flat surface as well as uniform height. Figure 6 shows the scanning electron micrographs of a Bi­Te leg of 20 µm-thickness overgrown and subsequently mechanical polished. It can be seen that the thin fi lm leg has fl at and relatively smooth surface. After electrodepositing 1 µm-thick Ni as an adhesion layer and 3 µm-thick Sn as a bonding layer on top of the Bi­Te and Sb­Te thin film legs, subsequent photoresist patterning and metallization etching were con- ducted to produce the electrodes of the bottom substrate. A scanning electron micrograph of the completed bottom substrate consisting of the Bi­Te and Sn­Te thin film legs with the Ni/Sn capping layer is shown in Fig. 7.
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Flat Roof Thin-Film PV Compared to Tilted Thin Film and Crystalline PV

Flat Roof Thin-Film PV Compared to Tilted Thin Film and Crystalline PV

against inherently uneconomical, energetically inefficient and dangerous nuclear power, etc. 2. CAN PV RISE TO THE CHALLENGE? One hinderance to PV achieving rapid growth is the lingering high cost and awkwardness of large-scale installation. To get beyond this limitation, the ElectroRoof™ thin-film flat roof PV system was designed to minimize field installation:

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Thin Film Solar Charge Controller: A Research Paper for Commercialization of Thin Film Solar Cell

Thin Film Solar Charge Controller: A Research Paper for Commercialization of Thin Film Solar Cell

One of the biggest problems with a-Si solar cells is the material used for its semiconductor. Silicon is not always easy to find on the market, where demand often exceeds supply. But the a-Si cells themselves are not particularly efficient. They suffer significant degradation in power output when they're exposed to the sun. Thinner a-Si cells overcome this problem, but thinner layers also absorb sunlight less efficiently. Taken together, these qualities make a-Si cells great for smaller-scale applications, such as calculators, but less than ideal for larger-scale applications, such as solar-powered buildings. Promising advances in non-silicon thin-film PV technologies are beginning to overcome the issues associated with amorphous silicon. On the next page, we'll take a look at CdTe and CIGS thin-film solar cells to see how they compare.
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K-Band Harmonic Dielectric Resonator Oscillator Using Parallel Feedback Structure

K-Band Harmonic Dielectric Resonator Oscillator Using Parallel Feedback Structure

Abstract—A novel K-band harmonic dielectric resonator oscillator (DRO) is presented. Two identical parallel feedback DROs constitute a symmetric structure by sharing the same dielectric resonator (DR). As a result of this special structure, the odd frequency output components offset while the even harmonic frequency components superimposed at the output port. Odd and even mode analysis method is used in theoretical analysis. As the experimental results shown, the fundamental frequency is 9.45 GHz and the output power at the second harmonic frequency of 18.9 GHz is 9.45 dBm. The suppression of fundamental frequency is about 15.5 dBc. A phase noise of −97 dBc/Hz@100 KHz and −78 dBc/Hz@10 KHz is achieved at the output frequency.
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THIN FILM GROWTH TECHNIQUES: IMPORTANCE OF THIN FILMS

THIN FILM GROWTH TECHNIQUES: IMPORTANCE OF THIN FILMS

reactor walls. They observed an increase in growth rate above 370 o C, which reaches a maximum value of 2.4 mm/hr at 450 o C. Wright et al. [14] in 1984 deposited ZnO thin films on GaP and glass slides using oxygen- containing heterocycle compounds such as furan, tetrahydrofuran, and tetrahydropyran to avoid the premature reactions observed with H 2 O and O 2 . They got promising results regarding the quality of the film, however the

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Active and passive coupled-resonator optical waveguides

Active and passive coupled-resonator optical waveguides

resonators as a low index contrast slow light structure. Despite the low index contrast, a high slowing factor is obtained by decoupling the length of the device in the prop- agation direction from the size of the resonators. Certain implementations of such CROWs are depicted in Fig. 7.1(a) and (b). A large slowing factor is possible because along z, the direction of propagation, the period of the device can be short, say about 5 µm for evanescently coupled single-mode waveguides. This periodicity is similar to what is achievable in high-index contrast photonic crystal, ring, or disk resonators. In the y direction, propagating optical waves are resonant with the cavities. Moreover, optical gain and electronic control can be readily incorporated into the coupled wave- guide array by leveraging diode laser array technologies [1, 143]. An optical signal can couple into the first array element in a side-coupled or end-coupled configuration as in Fig. 7.1(c)–(d). The output can then be out-coupled in a similar manner out of the last element of the array. The difference between the side-coupled and end- coupled structures is the presence of reflectors in the first and last waveguides in the end-coupled geometry. The differences in the input and output coupling mechanisms and configurations lead to a qualitative change of the transmission properties.
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On the vibration of a thin rectangular plate carrying a moving oscillator

On the vibration of a thin rectangular plate carrying a moving oscillator

Abstract. A great number of studies on the vibration of plates subjected to moving loads are available, which are gained by moving force and moving mass modeling frameworks. As a result, evaluating the reliability of the approximate simulation of a moving oscillator problem through moving force/mass would be of interest to engineering applications. Therefore, in this article, transverse vibration of a thin rectangular plate under a traveling mass-spring-damper system is revealed using the eigenfunction expansion method. Both moving force and moving mass modeling approaches are compared with the moving oscillator and various plate xity cases, and load trajectories are involved to present benchmark solutions. The spring stiness range, in which the plate response agrees closely with the corresponding moving force/mass analysis, is recommended. The results elucidate that the moving mass can be considerably unrealistic in predicting the contact force of an undamped oscillator. Moreover, errors in the orbiting force/mass simplication of the orbiting oscillator in predicting the resonant conditions of the plate vibration are not negligible.
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