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Microwave and Guided Wave Letters, IEEE

Issue 2 • Date Feb. 1998

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Displaying Results 1 - 19 of 19
  • A conductive wedge in Yee's mesh

    Publication Year: 1998 , Page(s): 66 - 68
    Cited by:  Papers (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (125 KB)  

    The authors present a correction of the finite-difference (FD) methods employing Yee's mesh, improving the accuracy when conductive edge corners are present in the analyzed structure. The algorithm allows the wedge to be arbitrarily located with respect to the grid points and yields significant error reduction. View full abstract»

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  • Wide-bandwidth Ku-band monolithic analog frequency divider

    Publication Year: 1998 , Page(s): 84 - 86
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (94 KB)  

    A new analog frequency divider configuration using a resistive field-effect transistor (FET) mixer with a series feedback is proposed. With this configuration, a large synchronization bandwidth of almost 30% has been achieved using an original CAD technique. This bandwidth has been effectively measured on a Ku-band monolithic microwave integrated circuit (MMIC) circuit together with an ultra-low power consumption. Moreover, the processed circuit using a standard 0.2-μm PHEMT technology (Philips-PML) is very compact (1.5 mm2). View full abstract»

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  • Single- and dual-feedback transimpedance amplifiers implemented by SiGe HBT technology

    Publication Year: 1998 , Page(s): 63 - 65
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (52 KB)  

    Monolithically integrated SiGe/Si heterojunction bipolar transistor (HBT) transimpedance amplifiers, with single- and dual-feedback configurations, have been designed, fabricated, and characterized. The single-feedback amplifier showed transimpedance gain and bandwidth of 45.2 dBΩ and 3.2 GHz, respectively. The dual-feedback version exhibits improved gain and bandwidth of 47.4 dBΩ and 3.3 GHz, respectively. Their performance characteristics are excellent in terms of their application in communication systems View full abstract»

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  • Novel fast multiline analysis of parasitic effects in CPW inductors for MMICs

    Publication Year: 1998 , Page(s): 72 - 74
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB)  

    The author presents a novel multiline modeling of monolithic microwave integrated circuit (MMIC) spiral inductors in coplanar waveguide (CPW) technology. Starting from transmission line parameters calculated for only single lines and pairs of lines, a distributed equivalent circuit is established for each section of multicoupled lines in the structure. It readily yields the S-parameters of the section. An adequate interconnection of sections having different topologies results in the S-matrix of the device. Our technique is wideband, fast, and fully scalable. It predicts on-line the effect of the underpass and of spurious propagation along the coplanar waveguide (CPW) grounding. It is shown that a significant frequency shift is due to the combination of those two effects. Results are validated by measurements on SOI inductors, up to the second self-resonance frequency View full abstract»

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  • Accurate modeling of thin conducting layers in FDTD

    Publication Year: 1998 , Page(s): 75 - 77
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (104 KB)  

    In recent papers the surface impedance condition is proposed to incorporate the effect of high conductivity of a material. This condition only takes the reflection at materials into account; the transmission through very thin layers is not considered. In this work, we introduce a similar approach to model both reflection and transmission when confronted with a thin layer of good, but not perfectly, conducting material View full abstract»

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  • A millimeter-wave quasi-optical amplifier array using inclined-plane horn antennas

    Publication Year: 1998 , Page(s): 81 - 83
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB)  

    A novel millimeter-wave quasi-optical amplifier array architecture is presented. The amplifier array consists of a horn antenna that tapers down to a parallel-plate waveguide. Stacked between the parallel-plates is a microstrip power divider circuit which feeds the active elements. At the output there is a similar power-combining circuit and transition to free space. Measurements on the active array show a maximum gain of 7.25 dB at 43.25 GHz and a bandwidth of 5.75 GHz View full abstract»

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  • Time-domain transmission matrix of lossy transmission lines

    Publication Year: 1998 , Page(s): 90 - 92
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (148 KB)  

    In this work the time-domain transmission matrix T of lossy transmission lines is numerically derived by the method of characteristics without employing any convolution and Fourier transform, and some interesting properties about the matrix are given. The transmission lines can be uniform or nonuniform. Transmission line parameters are explicit in the matrix, which makes it very useful in some practical applications View full abstract»

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  • Direct extraction of a distributed nonlinear FET model from pulsed I-V/pulsed S-parameter measurements

    Publication Year: 1998 , Page(s): 102 - 104
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    In this work, a method for the direct extraction of a field-effect transistor (FET) distributed model is presented. This technique makes use of both pulsed I-V and pulsed S-parameter measurements. Results given are very efficient, especially in terms of time computation and uniqueness. Using this method, the distributed model provides a reliable mean of describing the FET's distributive nature View full abstract»

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  • An isolated-open pattern to de-embed pad parasitics [CMOSFETs]

    Publication Year: 1998 , Page(s): 96 - 98
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (56 KB)  

    To meet radio frequency (RF) performance required in large market of wireless applications, CMOS transistors having a small unit gate width are preferred. To correctly estimate RF performance, parasitics of the on-wafer pads and interconnection metal lines should be de-embedded as in the advanced bipolar transistors. However, cutoff frequencies of small-size MOSFETs de-embedded by the conventional on-wafer dummy structures result in large overestimation. A new open pattern is proposed to solve the problem. The meaning and justification of the new de-embedding pattern are discussed View full abstract»

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  • Generalized material-independent PML absorbers for the FDTD simulation of electromagnetic waves in arbitrary anisotropic dielectric and magnetic media

    Publication Year: 1998 , Page(s): 52 - 54
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB)  

    To simply and effectively absorb waves propagating in anisotropic materials consisting of both arbitrary permittivity and permeability tensors, generalized material-independent perfectly matched layer (GMIPML) absorbers are proposed. Within the GMIPML absorbers, electric displacement D and flux density B are directly absorbed, whereas electric field E and magnetic field H are simultaneously absorbed through the relations between E and D as well as H and B. The proposed GMIPML absorber is validated by analyzing two-dimensional (2-D) hybrid waves View full abstract»

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  • Spatial power-combining using CPW-fed bowtie antennas

    Publication Year: 1998 , Page(s): 60 - 62
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (76 KB)  

    A new quasi-optical power-combiner geometry consisting of an array of bowtie antennas fed by coplanar waveguide is presented. The bowtie structure provides space to accommodate planar tuning structures as well as multiple devices. An oscillator circuit that includes a heterojunction field-effect transistor (HFET) and coplanar resonator is embedded in one arm of each antenna. Experimental results for a 4×4 array are provided and an equivalent circuit model used for the array design is described View full abstract»

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  • A K-band tunable microstrip bandpass filter using a thin-film conductor/ferroelectric/dielectric multilayer configuration

    Publication Year: 1998 , Page(s): 78 - 80
    Cited by:  Papers (46)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (104 KB)  

    We report on a gold/strontium titanate (Au-SrTiO3) thin-film K-band tunable bandpass filter on a lanthanum aluminate substrate. The two-pole filter has a center frequency of 19 GHz and a 4% bandwidth. Tunability is achieved through the nonlinear temperature dependence and the DC electric field dependence of the relative dielectric constant of SrTiO3. A center frequency shift of 0.85 GHz was obtained at 400 V DC bias and 77 K without degrading the insertion loss of the filter View full abstract»

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  • Novel 2-D photonic bandgap structure for microstrip lines

    Publication Year: 1998 , Page(s): 69 - 71
    Cited by:  Papers (379)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    A new two-dimensional (2-D) photonic bandgap (PBG) structure for microstrip lines is proposed, in which a periodic 2-D pattern consisting of circles is etched in the ground plane of microstrip line. No drilling through the substrate is required. Three PBG circuits were fabricated with different circle radii to determine the optimum dimensions, as well as a PBG circuit with the compensated right-angle microstrip bend. Measurements show that deep and wide stopbands can be achieved using this method View full abstract»

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  • Revisiting characteristic impedance and its definition of microstrip line with a self-calibrated 3-D MoM scheme

    Publication Year: 1998 , Page(s): 87 - 89
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (72 KB)  

    Characteristic impedance and its definition are revisited and discussed for microstrip line with a self-calibrated three-dimensional (3-D) method of moments (MoM). This 3-D MoM accommodates a scheme called short-open calibration (SOC) so that potential parasitic effects brought by the impressed voltage excitation and other relevant factors can be effectively removed. In this way, the characteristic impedance can be accurately defined through a relationship between equivalent voltage and current on the two sides of a microstrip line having a finite length. Simulated results are compared with the Jansen's two-dimensional (2-D) and Rautio's 3-D definition View full abstract»

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  • Differential formulation of on-surface measured equation of invariance for 2-D conducting scatterings

    Publication Year: 1998 , Page(s): 99 - 101
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (96 KB)  

    In this letter formulations of on-surface measured equation of invariance (OSMEI) method for two-dimensional (2-D) conducting scatterings are derived from scalar wave equations rather than integral equations. At the same time, the MEI equations for TM and TE cases are proved to be same. As long as one of the MEI equations of the above two cases is found, the MEI equation of another case is automatically given. A great advantage of the OSMEI method over the conventional boundary integration or differential equation method is that the OSMEI can solve conducting scattering problems efficiently. Examples of conducting circular and rectangular cylinder scatterings for both TM and TE case show that results of the OSMEI are in excellent agreement with those of the method of moments (MoM) View full abstract»

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  • Time-domain (FE/FDTD) technique for solving complex electromagnetic problems

    Publication Year: 1998 , Page(s): 93 - 95
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (84 KB)  

    A hybrid finite element finite-difference time-domain (FE/FDTD) technique for solving complex electromagnetic problems is presented. The method combines the computational simplicity of the structured FDTD scheme with the versatility as well as flexibility of the finite-element method (FEM) and enables us to accurately model curved geometries and those with fine features. Numerical results that illustrate the accuracy of the method are included View full abstract»

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  • A simple error correction method for two-port transmission parameter measurement

    Publication Year: 1998 , Page(s): 58 - 59
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (72 KB)  

    This letter presents a simple error correction method for two-port transmission parameter measurement. The method requires measuring only two nonreflecting transmission lines instead of a complete set of calibration standards (at least three) for error correction, it does not need an explicit solution of error coefficients. These two features make it simpler than any other methods. Error-corrected measurement results of a CPW discontinuity using the new method and the TRL method are in good agreement. The new method is useful in characterizing well-matched two-port devices or those whose reflection parameters are of little interest View full abstract»

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  • Comparative study of the PML and C-COM mesh-truncation techniques

    Publication Year: 1998 , Page(s): 55 - 57
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (84 KB)  

    The recently developed concurrent complementary operators method (C-COM) for mesh truncation of finite-difference time-domain (FDTD) problems has been shown to produce a substantial improvement in differential equation-based absorbing boundary conditions (ABCs). In this letter, the C-COM and the perfectly matched layer (PML) approaches are compared using two-dimensional problems. Two representative geometries are considered that address the absorption of evanescent waves and waves traveling at near-grazing incidence. It is found that the C-COM yields significant improvements over the PML solution for these geometries View full abstract»

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  • Input admittance of a coaxial-line-driven cylindrical cavity with a center dielectric rod

    Publication Year: 1998 , Page(s): 49 - 51
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (112 KB)  

    An expression for the input admittance of a coaxially driven cylindrical cavity is presented. Two cases are presented: first, where the coaxial-line transition is located on one of the flat walls of an empty cavity, and secondly where there is a dielectric rod located coaxially between the two flat walls of the cavity. A comparison between the theory and measurements is presented which shows that the model is capable of yielding a high level of accuracy View full abstract»

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Aims & Scope

This Periodical ceased production in 2000. The current retitled publication is IEEE Microwaves and Wireless Component Letters.

Full Aims & Scope