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- 实验方案
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Preparation and Research of Bi-YIG Nanoparticles via LTCC
摘要： Y3-xBixFe5O12 (Bi-YIG; x = 0.2–1.4) nanoparticles were successfully prepared at 925°C by a solid state reaction method using low temperature co-firing ceramic technology. The properties of the material were characterized using x-ray powder diffraction, a scanning electron microscope and differential scanning calorimetry. The test results reveal that the crystallinity, size and sintering temperature are obviously related to Bi concentration. It is proved that the addition of Bi2O3 can significantly decrease the sintering temperature, change microstructures and influence magnetic properties. The reason is that the sintering aid (Bi2O3) forms a liquid phase in the sintering process, accelerating the diffusion of the yttrium iron garnet (YIG) particles, the transformation of phases, and the formation of new substances. In addition, the liquid phase can greatly facilitate the rearrangement and mass transfer of the YIG particles, so it can promote sintering and drastically decrease the sintering temperature. It is also confirmed that the turning point (x = 0.8) is the best Bi concentration. Moreover, the dynamic properties of ferromagnetic resonance (FMR) curves were studied in field sweep and frequency sweep modes, and the symmetry and asymmetry mechanisms of the FMR spectrum were researched. Finally, The Bastrukov theory, and the Landau–Lifshitz model and inhomogeneous broadening or Gilbert damping (LLG model) were used to analyse the resonance mechanism. By comparing the advantages and disadvantages of the two fitting mechanisms, it is found that the fitting of the LLG model is the best.
关键词： LTCC,Bi-YIG nanoparticles,FMR,fitting
更新于2025-09-23 15:23:52
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Modular Ceramic-Polymeric Device for Analysis of Selected Elements in Liquid Using Microplasma
摘要： Miniaturization of devices for analysis of chemical composition is being still developed. In this article we present a portable device with a microplasma excitation source. The microdischarge is ignited inside a ceramic structure between a solid anode and a liquid cathode. As a result of cathode sputtering of the solution, it is possible to determine its chemical specimens by analysis of emission spectra of the microdischarge. We fabricated cathodes with a microfluidic compartment and two types of anodes. Devices were tested experimentally. Spectroscopic properties of the microdischarge and its analytical performance depended on the used ceramic structure, the surface area of the cathode aperture and the flow rate of the solution.
关键词： optical emission spectroscopy,microplasma,LTCC
更新于2025-09-23 15:23:52
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Enzymatic method of urea determination in LTCC microfluidic system based on absorption photometry
摘要： In this paper a novel microanalytical system based on absorption photometry for urea determination in small-volume biological samples is described. The developed microsystem with built-in microreactor with urease immobilised on its surface was fabricated using low temperature co-fired ceramics (LTCC) technology. For detection of the ammonium ions – product of urea hydrolysis, the modified Berthelot’s reaction was applied and conditions of this reaction were optimised in a way to be suitable for analysis in microsystems and for particular application, with special regards to very small alternation of urea concentration in culture medium. The best results were obtained for reagent R1 composed of: 180 mM sodium salicylate, 15 mM sodium nitroprusside, 2 mM EDTA in phosphate buffer solution of pH 7 and reagent R2 containing 16.9 mM sodium hypochlorite in phosphate buffer solution of pH 12. Linear concentration range of urea detection with the use of the developed LTCC microfluidic system for the selected flow rate of 4 μl/min, was in the range up to 1 mM, and the calculated lower limit of detection – 0.002 mM. The developed microsystem enables urea determination in samples of post-culture medium and of cells lysates of minimised volume c.a. 1 μl. Preliminary studies related to determination of urea in real samples, performed using hepatic cells lysates and post-culture medium were successful. As reference methods, commercially available tests were applied. The determined urea concentration measured by means of the QuantiChrom? and BioMaxima test and by the developed method based on the LTCC microanalytical system differs by c.a. 9% and 2% respectively. To the best of our knowledge, this is the first urea analysis microsystem for use in cells culture studies characterised by: the smallest volume of sample – 1 μl, long lifetime with stable response - reduced by 14%, through experimental time span of 30 days as well as suitability for quasi-monitoring of cells in vitro with sampling rate - 6 samples per hour.
关键词： LTCC technology,enzymatic microreactor,microfluidic systems,lab-on-a-chip,enzymatic urea determination,absorption photometry
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Reykjavik, Iceland (2018.8.8-2018.8.10)] 2018 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Design of Frequency Tunable LTCC Coaxial SIW Filters with Constant Passband Shape
摘要： This paper deals with the design of substrate integrated coaxial ?lters in multi-layer low temperature co-?red ceramic (LTCC) technology with centre frequency tunability, while keeping constant passband characteristics along the whole tuning range. A structure consisting on switchable embedded capacitances is employed. Moreover, inner and outer layers are used for implementing frequency-dependent coupling structures, enabling to match the required input/output and inter-resonator coupling levels at the different ?lter states. Thus, a tunable ?lter with four equidistant centre frequencies in the C-band is designed with nearly constant bandwidth (BW) at the different states. Experimental results show the validity of the proposed approach for implementing frequency tunable coaxial substrate integrated waveguide (SIW) ?lters with low losses, high selectivity and compact size.
关键词： LTCC,constant passband,coaxial resonators,tunable filters,SIW
更新于2025-09-23 15:21:21
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Structure, crystallization, and dielectric properties of the Al <sub/>2</sub> O <sub/>3</sub> filled CaO–B <sub/>2</sub> O <sub/>3</sub> –SiO <sub/>2</sub> –Al <sub/>2</sub> O <sub/>3</sub> glass composites for LTCC applications
摘要： The glass structures and crystallization behaviors of CaO–B2O3–SiO2 (C1) and CaO–B2O3–SiO2–Al2O3 (C1A03) glasses are investigated. The addition of Al3+ into CaO–B2O3–SiO2 glass acts as a glass former and bonds with the silicon tetrahedron with non-bridged oxygen to form Si–O–Al–O–Si, which increases the Q4 structural unit. The relative dielectric constants for C1 and C1A03 glass systems were all about 7.8–8.4. Compared to the C1 glass, the size and amount of pores decreased for the C1A03, leading to a higher dielectric constant. The C1A03 glass system exhibits better Qxf value than the C1 system due to the decrease in the size and amount of pores. The Qxf value roughly decreased with increasing glass addition for the densified samples. The C1A03 glasses with 50 wt% alumina exhibited the highest dielectric constant (8.4) and Qxf value (3150 GHz) due the maximum densification and highest amount of anorthite were obtained.
关键词： crystallization,dielectric properties,CaO–B2O3–SiO2–Al2O3 glass,LTCC,Al2O3
更新于2025-09-11 14:15:04
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SUBSTRATE INTEGRATED WAVEGUIDE FILTER WITH IMPROVED STOPBAND PERFORMANCE USING LTCC TECHNOLOGY
摘要： A novel multi-layer third-order substrate integrated waveguide (SIW) bandpass ?lter with improved lower stopband performance is proposed. TE201-mode in folded-SIW cavity is utilized to implement negative cross coupling, and the TE101-mode is taken as a non-resonating node (NRN) for implementing bypass coupling. A circular aperture etched on the middle metal layer is used to realize coupling between source and the second SIW cavity. Then, three transmission zeros located below the passband can be obtained to improve stopband attenuation. Meanwhile, better spurious suppression performance above passband is achieved. A ?lter sample is designed and fabricated with multi-layer low-temperature co-?red ceramic (LTCC) technology. The measured S-parameters agree well with the simulated ones, with its predicted good performance.
关键词： transmission zeros,low-temperature co-?red ceramic (LTCC),Substrate integrated waveguide (SIW),bandpass ?lter,stopband performance
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Atlanta, GA, USA (2019.7.7-2019.7.12)] 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Grounded Coplanar Waveguide-Fed Millimeter Wave Volumetric Pyramidal Horn on LTCC
摘要： There is a strong interest to implement antenna-in-package (AiP) systems for a variety of applications such as imaging, beamforming, integrated transceivers, and radars. Substrate integrated horn antennas are valuable AiP candidates due to their small form factor, ease of integration, and high gain. Alternatively, a volumetric packaging approach can significantly reduce the antenna’s form factor and enhance the gain. For the first time, in this paper, we present a 94 GHz low temperature cofired ceramic (LTCC) integrated volumetric pyramidal horn antenna. Using a vertical LTCC approach, a GCPW-fed single horn antenna was designed. Results show that the antenna operates from 91.6 GHz to 95.6 GHz for S11 <10 dB, with a realized gain of 8.7 dBi.
关键词： Antenna in Package,Low Temperature Co-fired Ceramic (LTCC),Volumetric Horn Antenna,94 GHz
更新于2025-09-11 14:15:04
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[IEEE 2018 48th European Microwave Conference (EuMC) - Madrid, Spain (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - Liquid Crystal Based SPDT with Adjustable Power Splitting Ratio in LTCC Technology
摘要： This paper presents design and characterisation of a new liquid crystal (LC) based single-pole double-throw (SPDT) with continuously adjustable power splitting ratio in low temperature co-fired ceramic (LTCC) technology. It is designed for a centre frequency of 30 GHz, the fully embedded LC phase including a key component, shifter in stripline topology. The SPDT shows a good matching with |S11| = ?10 dB over a bandwidth of 18 %. It exhibits an insertion loss of 9 dB to 11 dB and an isolation between 22 dB to 32 dB. The continuous tuneability not only allows the selection of each preferred power splitting ratio at the output ports, but also a tuning of the centre frequency. The high insertion loss arises from a certain surface roughness as well as a decreased conductivity of the gold metallisation used.
关键词： single-pole double-throw (SPDT),low temperature co-fired ceramic (LTCC),Liquid crystal
更新于2025-09-04 15:30:14
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HIGHLY INTERGRATED X-BAND LTCC RECEIVER MODULE
摘要： A highly integrated X-band receiver module is designed based on a 10-layered low temperature co-fired ceramic (LTCC) substrate. A compact X-band bandpass filter (BPF), an intermediate frequency (IF) band hybrid and an IF band BPF are proposed for the receiver module. The measured gain parameter of the proposed receiver is higher than 51 dB, and noise figure (NF) and image rejection are better than 2.5 dB and 37 dB, respectively. The overall size of the receiver module is only 54 mm × 15 mm × 1 mm. Comparisons and discussions are also provided.
关键词： receiver module,bandpass filter,LTCC,hybrid,X-band,image rejection
更新于2025-09-04 15:30:14
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[IEEE 2018 7th Electronic System-Integration Technology Conference (ESTC) - Dresden, Germany (2018.9.18-2018.9.21)] 2018 7th Electronic System-Integration Technology Conference (ESTC) - Compact LTCC Packaging and Printing Technologies for Sub–THz Modules
摘要： Low Temperature Co-fired Ceramics (LTCC) is a ceramic multilayer material with properties that suit well as both as a substrate and packaging material. LTCCs multilayer capabilities, excellent electrical properties, extremely high reliability and full hermetic nature suit it to a wide range of RF applications. Several frequency bands of interest from 100 GHz up to 300 GHz could potentially benefit from the use of LTCC system in package devices. To test the ability of LTCC materials at these frequencies, several grounded coplanar waveguide (GCPW) on 35-60 μm thick LTCC substrates were manufactured with the help of high-resolution Aerosol Jet printing technique and measured from 1-320 GHz (Ferro A6M-E) and 1-220 GHz, respectively (DuPont 9k7). For the first time, LTCC material are characterized as mm-wave circuit substrates at the frequency band of 220-320 GHz.
关键词： high frequency,MMIC,high resolution,LTCC,thick-film,Aerosol Jet printing,H-Band,radar
更新于2025-09-04 15:30:14