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《Microwave Theory and Techniques》2005,53(1):174-182
A new physical realization of an elliptic function filter response is proposed for achieving compact size, wide bandwidth, wide spurious free stopband and high-selectivity performance. The filter configuration can be implemented in conventional waveguide technology or embedded in a multilayer low-temperature co-fired ceramic structure for integration with other circuitry in a chip module. The filter is analyzed using rigorous mode matching. To validate the concept, prototypes of four- and six-cavity elliptic filters are designed following a systematic procedure. Approximate synthesis is used to obtain initial dimensions of the filter and the desired optimum response is obtained by means of a final full-wave optimization. The results are verified with other numerical methods and with the measurements of a fourth-order waveguide filter. 相似文献
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The theory of a new ferrite-filled rectangular waveguide phase shifter is presented, showing that the device offers more than twice the maximum phase shift of a classical dual-slab ferrite-loaded waveguide phase shifter. The complete analytical field derivation of the new phase shifter is presented. The prototype 36-GHz phase shifter has been completely embedded in an uncharacterized experimental low-temperature cofired ferrite ceramic material, essentially becoming an integral part of a chip package. The fabricated prototype is only 3.5-cm long, 5-mm wide, and 1-mm high. Preliminary measurements of the nonoptimized prototype reveal a controllable, nonreciprocal phase shift of 52.8/spl deg/ at 36 GHz for a bias current of 500 mA, and an insertion loss of approximately 3.6 dB, including transition loss. This paper marks the first time that a ferrite waveguide phase shifter has been realized as a lightweight, compact, and rugged module that can be easily mass produced at low cost. Since it is embedded in a package, the phase shifter can be readily integrated with other active and passive system components that would ideally be contained within the same package. 相似文献
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Jones W.K. Yanqing Liu Mingcong Gao 《Components and Packaging Technologies, IEEE Transactions on》2003,26(1):110-115
With projected power densities above 100 W/cm/sup 2/ for devices, new methods for thermal management from the heat generation at the die to heat removal to the ambient must be addressed. By integrating micro heat pipes directly within the ceramic substrate, effective thermal conductivity for spreading heat in both radial and axial directions was achieved. New materials and processes were developed to fabricate the unique components required to handle high thermal loads. Enhanced thermal vias to minimize the thermal impedance through the ceramic in the evaporator and condenser sections were developed, increasing the effective thermal conductivity from 2.63 to near 250 W/m-/spl deg/C. The use of an organic insert fabricated into the desired complex shape using rapid prototyping methods, coupled with the viscoelastic flow of the low temperature cofire ceramic (LTCC) during lamination, allowed complex shapes to be developed while ensuring uniform green tape density during lamination prior to tape firing. Large cavities, three-dimensional fine structures and porous wicks for capillary 3-D flow have been utilized to fabricate the heat pipes. Heat pipes and spreaders, utilizing water as the working fluid, have been demonstrated operating with power densities in excess of 300 W/cm/sup 2/. 相似文献
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低温共烧陶瓷(LTCC)介质是无源集成和系统级封装技术的关键材料。由于烧结工艺上的特殊要求,这类材料具有较传统电子陶瓷更复杂的显微结构,在材料的设计上难度更大。从材料的组成、结构、形成机制及其性质之间的关系出发,分析了探索新型LTCC介质材料的关键因素和设计策略,并通过对以作者研究组成功设计出的新型低介电常数LTCC材料——硅铝氟氧化物基LTCC介质为典型案例的剖析,论证了基于材料科学的基本原理实现对LTCC介质进行设计的可行性。 相似文献
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Hui-Wen Yao Abdelmonem A.E. Ji-Fuh Liang Xiao-Peng Liang Zaki K.A. Martin A. 《Microwave Theory and Techniques》1993,41(12):2166-2173
Scattering parameters of E- and H-plane stepped waveguide and E-plane ridge waveguide stepped T-junctions are obtained using an extension of the three-plane mode matching method. An optimization process is applied to find the T-junctions and step dimensions that yield a low reflection coefficient in one of the T-junctions arms over a wide frequency band. An example of the design of a wideband T-junction diplexer is presented. The diplexer filters are inductive window waveguide filters, and are rigorously modeled using mode matching and a novel two-dimensional curve fitting method, which greatly reduces the CPU time for optimization. The diplexer optimization procedure, as well as the filter modeling method, are described. Experimental results on the optimized T-junction and the diplexer are presented; both show excellent agreement with their computed optimum results, without any adjustments or tuning 相似文献
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Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory. 相似文献
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A method for manufacturing embedded variable capacitors (varactors) inside a low-temperature cofired ceramic substrate is presented. A varactor is fabricated by filling a via hole with ferroelectric barium strontium titanate paste. The measured capacitance of the varactor changed from 1.47 to 0.97 pF and the Q factor from 18.2 to 31.5 at 1 GHz when the bias voltage was increased from 0 to 200 V. 相似文献
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A TEM-mode theory, recently advanced to explain the operation of evanescent-mode filters, is shown to be incorrect. The transition from conventional direct-coupled iris-type waveguide filters to evanescent-mode filters is shown qualitatively in two simple steps. 相似文献
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A GaAs-based high-index-contrast ridge waveguide laser is fabricated using a self-aligned process of deep dry etching plus oxygen-enhanced wet thermal oxidation of low Al-content AlGaAs. Lasers operating at /spl lambda/=813 nm (CW, 300 K) with external differential quantum efficiencies as high as 78% are demonstrated, indicating effective passivation of the directly-oxidised etched active region sidewall surface. 相似文献
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The design of a high modulation response multiple-quantum-well ridge waveguide laser in AlGaAs-GaAs, with low parasitics is discussed. The device was fabricated on a semi-insulating substrate with a wide top contact, and airbridges have been used to connect the ridge top contact to the bonding pads on the semi-insulating substrate. The 3-dB frequency response of the laser has been measured to be 21 GHz, which is a record for unstrained quantum-well AlGaAs-GaAs lasers. 相似文献
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C.M. Harding Y.C. Chen R.J. Dalby 《Photonics Technology Letters, IEEE》1991,3(3):199-201
Ridge waveguide laser diodes of a GaAs-AlGaAs separate-confinement graded-index monolithically stacked triple-quantum-well structure have been fabricated. Chemically assisted ion beam etching (CAIBE) was used to etch a 4- mu m-wide mesa which serves as the waveguide for the device. Results for 4- mu m-wide by 600- mu m-long optically coated devices are presented. Single-longitudinal mode, CW output power in excess of 90 mW and a far-field divergence of 21 degrees *3.5 degrees are demonstrated.<> 相似文献
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Serkan Şimşek Sasan Ahdi Rezaeieh 《AEUE-International Journal of Electronics and Communications》2013,67(11):981-983
An efficient design method for substrate integrated waveguide electromagnetic bandgap (SIW-EBG) filters is proposed which provides direct dimensional synthesis approach for desired filter objectives without using network representations. The method is applied to the design of an X band SIW-EBG filter and its response is compared with HFSS (high frequency structure simulator) simulations for validation purposes. Fairly good agreement between the results shows the applicability of the proposed method for SIW-EBG filter design. 相似文献
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Narrow-bandwidth optical waveguide transmission filters 总被引:2,自引:0,他引:2
A general method for fabricating narrowband transmission filters at optical frequencies is proposed. For fibre- or integrated-optic applications the method consists of forming a waveguide loop by connecting the output ports of a 3dB coupler to each other. A Bragg reflection grating in the loop determines the filters frequency response. 相似文献
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A new method for implementing the multilayered filter is proposed. By properly controlling the behaviour of the coupling, two transmission zeros can be located at the same, lower or higher side of the passband's skirt. Moreover, measurements of fabricated examples match well with the electromagnetic simulation, which validates the proposed structure. 相似文献
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A ridge waveguide longitudinal-slot antenna array with a compact transverse dimension is introduced. To broaden the bandwidth of the array, it is divided into two sub-arrays fed by a novel compact convex waveguide divider. A 16-element uniform linear array at X-band was fabricated and measured to verify the validity of the design. The measured bandwidth of S/sub 11//spl les/-15 dB reaches 14.9% while the measured cross-polarisation level is less than -36 dB over the entire bandwidth. 相似文献
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LTCC基板制造工艺研究 总被引:8,自引:0,他引:8
低温共烧多层陶瓷(LTCC)基板是制造复杂微电子产品多芯片组件(MCM)的重要部件。详细地讨论了LTCC基板制造工艺,介绍了多年研究之经验及国外的有关技术,还指出了目前工艺中存在的技术问题及在工艺水平上与国外的差距。采用目前工艺,可做出20层布线、线宽及间距均为0.20mm、80mm×80mm的多层共烧基板 相似文献