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Microwave Theory and Techniques, IEEE Transactions on

Issue 12 • Date Dec. 2008

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  • Table of contents

    Publication Year: 2008 , Page(s): C1 - C4
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    Freely Available from IEEE
  • IEEE Transactions on Microwave Theory and Techniques publication information

    Publication Year: 2008 , Page(s): C2
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  • Electrical Characterization and Small-Signal Modeling of InAs/AlSb HEMTs for Low-Noise and High-Frequency Applications

    Publication Year: 2008 , Page(s): 2685 - 2691
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1265 KB) |  | HTML iconHTML  

    Electrical characterization and modeling of 2 times 50 mum gatewidth InAs/AlSb HEMTs with 225 nm gate-length have been performed. The fabricated devices exhibited a transconductance gm of 650 mS/mm, an extrinsic cutoff frequency fT and an extrinsic maximum frequency of oscillation fmax of 120 and 90 GHz, respectively, already at a low VDS of 0.2 V. A minimum noise figure less than 1 dB between 2-18 GHz was achieved at a dc power consumption of only 10 mW/mm. This demonstrates the potential of InAs/AlSb HEMTs for low-power, low-noise applications. To account for the elevated gate-leakage current lG in the narrow-bandgap InAs/AlSb HEMT, the conventional field-effect transistor small-signal model has been extended. The relatively high IG was modeled by shunting both Cgs and Cgd with Rgs and .Rgd, respectively. As a result, the small-signal S-parameters were more accurately modeled, especially for frequencies below 10 GHz. Utilizing this modeling approach, excellent agreement was obtained between measured and modeled S-parameters, unilateral power gain U (Mason's gain) and stability factor K. View full abstract»

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  • A General Statistical Equivalent-Circuit-Based De-Embedding Procedure for High-Frequency Measurements

    Publication Year: 2008 , Page(s): 2692 - 2700
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1562 KB) |  | HTML iconHTML  

    A general equivalent-circuit-based method for the de-embedding of scattering parameters is presented. An equivalent circuit representation is used to model the embedding package. The parameters in the models are estimated with a statistical method using measured data from all de-embedding standards jointly together. Hence, it is possible to assess parameter estimates and their variance and covariance due to measurement uncertainties. A general de-embedding equation, which is valid for any five-port with a defined nodal admittance matrix, is derived and used in the subsequent de-embedding of measured device data. Different equivalent circuit models for the embedding network are then studied, and tradeoffs between model complexity and uncertainty are evaluated. Furthermore, the influence of varying number and combinations of de-embedding standards on the parameter estimates is investigated. The method is verified, using both measured and synthetic data, and compared against previously published work. It is found to be more general while keeping or improving accuracy. View full abstract»

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  • Fast Passivity Assessment for S -Parameter Rational Models Via a Half-Size Test Matrix

    Publication Year: 2008 , Page(s): 2701 - 2708
    Cited by:  Papers (26)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (553 KB) |  | HTML iconHTML  

    Rational models must be passive in order to ensure stable time domain simulations. The assessment of passivity properties is usually done via a Hamiltonian matrix that is associated with the state-space model, allowing precise characterization of passivity violations from its imaginary eigenvalues. The calculation of eigenvalues can be time consuming for large models as the matrix size is equal to twice the number of model states. In this paper, we derive for S-parameter models a new test matrix which is only half the size of the Hamiltonian matrix. This leads to savings in the eigenvalue computation time by a factor of nearly eight. The new test matrix takes into account that the model is symmetrical, in pole-residue form. Its application is demonstrated by three examples: a microwave filter, a package, and a synthetic model. View full abstract»

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  • Temperature-Dependent RF Large-Signal Model of GaN-Based MOSHFETs

    Publication Year: 2008 , Page(s): 2709 - 2716
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (785 KB) |  | HTML iconHTML  

    A temperature-dependent RF large-signal model is constructed by modifying the Verilog-A code of the Angelov model for unique characteristics of GaN MOSHFETs. Different from the previously reported EEHEMT-based model, the present electro-thermal model can fit the temperature effects on threshold shift and transconductance degradation, the drain current in the linear region, and the gate capacitance near the cutoff region. As the result, the power, gain, efficiency, linearity, drain current, and gate current of both Class-A and Class-AB amplifiers are accurately simulated over a wide range of input powers, matching impedances, and ambient temperatures. View full abstract»

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  • Electro-Thermal Theory of Intermodulation Distortion in Lossy Microwave Components

    Publication Year: 2008 , Page(s): 2717 - 2725
    Cited by:  Papers (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (772 KB) |  | HTML iconHTML  

    An analytic formulation of dynamic electro-thermally induced nonlinearity is developed for a general resistive element, yielding a self-heating circuit model based on a fractional derivative. The model explains the 10 dB/decade slope of the intermodulation products observed in two-tone testing. Two-tone testing at 400 MHz of attenuators, microwave chip terminations, and coaxial terminations is reported with tone spacing ranging from 1 to 100 Hz. View full abstract»

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  • High-Frequency Characteristic Fluctuations of Nano-MOSFET Circuit Induced by Random Dopants

    Publication Year: 2008 , Page(s): 2726 - 2733
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1057 KB) |  | HTML iconHTML  

    As the dimension of semiconductor device shrunk into nanometer scale (nanoscale), characteristic fluctuation is more pronounced, and become crucial for circuit design. In this paper, discrete-dopant-induced characteristic fluctuation of 16-nm-gate metal-oxide-semiconductor field effect transistors (MOSFET) circuit under high-frequency regime is quantitatively studied. The circuit gain, the 3 dB bandwidth and the unity-gain bandwidth of the tested nanoscale transistor circuit are calculated concurrently capturing the discrete-dopant-number- and discrete- dopant-position-induced fluctuations in the large-scale statistically sound ldquoatomisticrdquo device/circuit coupled simulation. For the 16-nm-gate MOSFET circuit, the number of discrete dopants, varying from zero to 14, may result in 5.7% variation of the circuit gain, 14.1% variation of the 3 dB bandwidth, and 10.4% variation of the unity-gain bandwidth. To suppress the high-frequency characteristic fluctuations, an improved doping distribution along the longitudinal diffusion direction from the MOSFET's surface to substrate is further performed to examine the associated fluctuation. The improved vertical doping profile with less dopants locating near surface of channel effectively reduces the fluctuations of the circuit gain, the 3 dB bandwidth and the unity-gain bandwidth dramatically. Compared with the original doping profile, the reduction is 32.3%, 19.4% and 51.8%, respectively. This study provides an insight into random-dopant-induced intrinsic high-frequency characteristic fluctuations and verifies the potential fluctuation suppression technique on high-frequency characteristic fluctuations of nanoscale transistor circuit. View full abstract»

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  • A New Low Loss Rotman Lens Design Using a Graded Dielectric Substrate

    Publication Year: 2008 , Page(s): 2734 - 2741
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1123 KB) |  | HTML iconHTML  

    In this paper, a new low loss graded dielectric Rotman lens design is presented. The graded dielectric allows for the enhanced focusing of the energy between the beam ports and the array ports of the lens, thereby minimizing the energy spill-over to the Rotman lens sides. New lens design equations are presented, which account for the change in effective wavelength and ray bending within the lens. The graded dielectric within the lens was fabricated by forming a periodic lattice of voids, with a variable density, in the lens substrate. Compared to a conventional Rotman lens, the new graded dielectric Rotman lens shows a measured insertion loss improvement of up to 2.1 dB. In addition, the degradation in peak power at the extreme scan angles is improved from 1.5 to 0.7 dB. View full abstract»

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  • Multipole Spatial Filters Using Metamaterial-Based Miniaturized-Element Frequency-Selective Surfaces

    Publication Year: 2008 , Page(s): 2742 - 2747
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2020 KB) |  | HTML iconHTML  

    This paper presents a novel multipole miniaturized-element frequency-selective surface (FSS) having a very low thickness and a desired multipole frequency response. For this design, new miniaturized elements for the FSS are developed to achieve low thickness solution and improved functionality. The proposed FSS enables implementation of higher order spatial filters over low-profile conformal antenna arrays. First, design of a very thin-layer modified miniaturized-element FSS producing a single-pole bandpass response in addition to a transmission zero is presented. The modified design is just a single-sided circuit board with a particular unit cell consisting of a loop centered within a wire grid. Next, using a similar metallic pattern on the other side of a very thin substrate, a dual-bandpass frequency response is produced. This response is achieved by choosing proper dimensions for the loops and wire of each layer and by appropriately positioning the layers with respect to each other. To establish a benchmark, dual-pole FSSs using cascaded layers of a previously designed miniaturized-element FSS are considered. In comparison, the modified dual-bandpass design has only two metal layers, instead of four, and a single substrate, instead of three. The proposed multipole FSS has a thickness of lambda/300 which is six times thinner than the benchmark structures. Moreover, the frequency response of the new FSS shows higher out-of-band rejection values. Performance of the multipole screens is tested by fabricating FSSs with maximally flat and dual-bandpass responses and measuring their frequency responses using a standard measurement setup in a free-space environment. View full abstract»

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  • Inverse Class-F AlGaN/GaN HEMT Microwave Amplifier Based on Lumped Element Circuit Synthesis Method

    Publication Year: 2008 , Page(s): 2748 - 2753
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1023 KB) |  | HTML iconHTML  

    A lumped element design method considering more than third-order higher harmonic frequencies for a microwave AlGaN/GaN HEMT inverse class-F amplifier has been developed. The load circuit consists of a series reactance network having zero impedance at the odd order harmonic frequencies and poles at the even order higher harmonic frequencies as well as a shunt reactance network having zero impedance at the odd order harmonic frequencies. A fabricated AlGaN/GaN HEMT inverse class-F amplifier delivered a power-added efficiency of 76.3% and a drain efficiency of 78.3% at 879 MHz. View full abstract»

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  • A 2.4–5.4-GHz Wide Tuning-Range CMOS Reconfigurable Low-Noise Amplifier

    Publication Year: 2008 , Page(s): 2754 - 2763
    Cited by:  Papers (13)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1394 KB) |  | HTML iconHTML  

    A 2.4-5.4-GHz CMOS reconfigurable low-noise amplifier (LNA) is designed. It consists of two stages: a broadband input stage for a steady input matching and noise performance, and a reconfigurable band-selective stage which provides a wide-range frequency tuning from 2.4 to 5.4 GHz and a 12-dB stepped gain with linearity adjustment. The frequency tuning is conducted by a multitapped switching inductor and varactors. Careful design of the switching inductor achieves consistent performance among frequency configurations. The stepped gain and linearity adjustment are provided by a size-switchable transistor with a variable biasing. Fabricated in 0.13 mum CMOS technology this LNA exhibits performance including up to 25 dB power gain, 2.2-3.1 dB noise figure and less than 5 mW power consumption under 1 V power supply. View full abstract»

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  • Design and Analysis of a Multiport Circuit for Shaping Sub-Nanosecond Pulses

    Publication Year: 2008 , Page(s): 2764 - 2770
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1620 KB) |  | HTML iconHTML  

    In this study, a coupled-line coupler was evaluated for its potential to shape sub-nanosecond ultra-wideband (UWB) pulses. The coupler was shown to exhibit a natural tendency to differentiate sub-nanosecond pulses, owing to its bandpass nature. Next, a Schottky detector diode was applied to confirm that the small parasitic reactance in the coupler gives rise to the differentiation behavior. The unconventional application of a coupler and Schottky diode towards signal differentiation culminated in the development of a novel UWB generator that simultaneously produces: a square waveform that has a 20%-80% rise time of 850 ps, a Gaussian waveform that has a pulse duration of 100 ps, and a monocycle waveform that has a 80 ps rise time between its peaks. These waveforms were obtained by taking advantage of the dc isolation of the coupled line structure and using step recovery diodes to compress the edges of a 14 MHz sinusoidal source. The resulting multiport circuit for simultaneous shaping of sub-nanosecond pulses (MCS3P) showed good agreement between measured and simulated results. View full abstract»

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  • Penetrating 3-D Imaging at 4- and 25-m Range Using a Submillimeter-Wave Radar

    Publication Year: 2008 , Page(s): 2771 - 2778
    Cited by:  Papers (76)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (795 KB) |  | HTML iconHTML  

    We show experimentally that a high-resolution imaging radar operating at 576-605 GHz is capable of detecting weapons concealed by clothing at standoff ranges of 4-25 m. We also demonstrate the critical advantage of 3-D image reconstruction for visualizing hidden objects using active-illumination coherent terahertz imaging. The present system can image a torso with <1 cm resolution at 4 m standoff in about five minutes. Greater standoff distances and much higher frame rates should be achievable by capitalizing on the bandwidth, output power, and compactness of solid state Schottky-diode based terahertz mixers and multiplied sources. View full abstract»

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  • A Low-Loss Substrate-Independent Approach for 60-GHz Transceiver Front-End Integration Using Micromachining Technologies

    Publication Year: 2008 , Page(s): 2779 - 2788
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1700 KB) |  | HTML iconHTML  

    This paper presents a low-loss, substrate-independent approach to integrate transceiver front-ends for 60-GHz wireless applications. Dielectric loss is eliminated by using polymer and bulk silicon micromachining technologies to create a cavity-based duplexer and a horn antenna in the air, above the substrate. A coplanar waveguide input is used for easy integration of the low-noise amplifier and power amplifier of the receiver and transmitter, respectively, with the micromachined passive module. A prototype is designed, fabricated, and characterized, with the transmit band (TX) set between 58.7-59.5 GHz and the receive band (RX) as 60.6-61.4 GHz. The proposed method offers an easy integration of both planar components and 3-D integrated modules on top of the substrate. View full abstract»

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  • Electrically Tunable Antenna Design Procedure for Mobile Applications

    Publication Year: 2008 , Page(s): 2789 - 2797
    Cited by:  Papers (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1506 KB) |  | HTML iconHTML  

    Using a high-efficiency tunable antenna to cover a large bandwidth with low return loss is an interesting topic, especially in the case when the physical sizes of the mobile phone and antenna are too small to allow for the coverage of the full band. The limitations of tunable antennas are their losses and the nonlinearity introduced by the tuning devices. A design procedure for the tunable mobile antennas is presented, which accounts for the nonlinearity suppression. Following this procedure, a low-loss tunable digital video broadcasting-handheld (DVB-H) antenna has been designed and fabricated to cover the DVB-H band (470-702 MHz) with a return loss below 7 dB. This antenna exhibits a small volume of only 6 cm3 . Despite the high-power signal from the extended global system for mobile communication transmitter on the same printed circuit board and the nonlinear tuning devices, this antenna is highly linear. View full abstract»

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  • High-Current–High-Speed Dynamic Bias Control System Applied to a 100-W Wideband Push–Pull Amplifier

    Publication Year: 2008 , Page(s): 2798 - 2807
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2621 KB) |  | HTML iconHTML  

    This paper presents a dynamic bias control system applied to a high power wideband amplifier. The amplifier used is based on a push-pull topology with LDMOS transistors and works in the 50-500 MHz frequency bandwidth. It delivers a nominal 100 W output power with 60% power-added efficiency (PAE) when it is fed with continuous signals. When it is driven by a 16QAM modulated signal, 6 dB input power back-off is necessary to keep an error vector measurement below 5%. This usual back-off technique results in lower PAE (43% in our case). By implementing the proposed bias control system, both 55% PAE and 5% EVM have been reached for 75 W average output power. The drain bias control circuit handles high currents and high voltages (7 A-28 V). The proposed implementation makes use of a class S modulator driven by a SigmaDelta modulator. Up to 1 Mbit/s envelope bit rate can be efficiently and accurately processed by using here dedicated circuits running at 20 MHz clock frequency. View full abstract»

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  • Response of RF Networks to Transient Waveforms: Interference in Frequency-Hopped Communications

    Publication Year: 2008 , Page(s): 2808 - 2814
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (961 KB) |  | HTML iconHTML  

    The long-tail transient responses of a bandpass network to pulsed and switched-tone stimuli are examined and a time-domain closed-form expression of the envelope response is developed. It is shown that the long-tail response leads to interference in frequency-hopping communication systems. Interference, and in particular co-site interference, can result in any radar, communication, or RF sensor system becoming exposed to unintentional pulsed RF signals. In the experimental study, 900-MHz Chebyshev bandpass filters are considered. View full abstract»

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  • Full-Wave Hybrid Technique for 3-D Isotropic-Chiral-Material Discontinuities in Rectangular Waveguides: Theory and Experiment

    Publication Year: 2008 , Page(s): 2815 - 2825
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2440 KB) |  | HTML iconHTML  

    Numerical results obtained using a full-wave hybrid technique (comprising a new formulation of the coupled-mode method and the mode-matching method) for treating 3-D isotropic- chiral-material discontinuities in rectangular wave guides with perfect electrically conducting walls were compared with experimental data. For that purpose, samples of an isotropic chiral material were manufactured as composite materials. These samples were then fully characterized in the X-band. The measured constitutive parameters were used in the full-wave hybrid technique to predict the scattering parameters of three different structures-each a waveguide filled partially with the isotropic chiral material. The scattering parameters were also measured. The predicted and measured scattering parameters were in reasonably good agreement. View full abstract»

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  • Full-Wave Modal Dispersion Analysis and Broadside Optimization for a Class of Microstrip CRLH Leaky-Wave Antennas

    Publication Year: 2008 , Page(s): 2826 - 2837
    Cited by:  Papers (55)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1806 KB) |  | HTML iconHTML  

    In this paper, a planar microstrip composite right/left-handed leaky-wave antenna is analyzed and designed as an infinite 1-D periodic microstrip leaky-wave antenna. A parametric study, based on a full-wave numerical modal approach that analyzes a unit cell using a periodic layered-medium Green's function, is shown to be an efficient approach to accurately design the structure, completely eliminating open-stopband effects and achieving an almost constant radiation efficiency when the beam is scanned through broadside. Results obtained by the proposed approach are compared with those obtained by means of both an artificial transmission-line analysis and a Bloch-wave analysis, which use the full-wave simulation of a finite-length structure. The balanced condition is interpreted in terms of the behavior of the phase and attenuation constants relevant to the radiating harmonic. Furthermore, it is shown how radiation at broadside is guaranteed by the presence of two radiating elements (one series and one shunt) within the equivalent circuit of the unit cell. The effectiveness of the analysis is demonstrated through the design of a finite-length antenna excited by a source at one end. View full abstract»

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  • Time-Frequency Formulation for the Nonlinear Analysis of Coupled Phase-Locked Loops

    Publication Year: 2008 , Page(s): 2838 - 2850
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1580 KB) |  | HTML iconHTML  

    In this work, harmonic balance (HB) and envelope- transient formulations of coupled phase-locked loops (CPLLs) are presented. The CPLL has the added difficulty of its autonomous behavior since no reference oscillator is present. The new formulation takes into account the autonomy of the system, introducing a special set of state variables, which depend on the autonomous frequencies. The hysteresis phenomenon in CPLLs is analyzed in detail, efficiently obtaining the pull-in and hold-in ranges through HB. The pole analysis of the perturbed HB system enables an accurate prediction of instabilities and resonances. Due to the CPLL autonomy, there exists an inherent noise accumulation effect. This effect is taken into account, analyzing the perturbation in terms of accumulation and deviation components. The envelope formulation allows simulating the CPLL behavior in the presence of modulation signals. The influence of the stability of the steady-state solution on the modulated signals is investigated. The simulation results have been successfully compared with the measurements in a manufactured CPLL system at 2 GHz. View full abstract»

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  • Parameterized Model-Order Reduction for Efficient Eigenanalysis of Dielectric Waveguide Structures

    Publication Year: 2008 , Page(s): 2851 - 2858
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1056 KB) |  | HTML iconHTML  

    This paper presents an efficient method for fast wideband eigenmode analysis of waveguide structures. The proposed algorithm uses a multidimensional subspace method based on modified perturbation theory and singular-value decomposition to perform model-order reduction directly on the finite element eigenvalue equations. This procedure generates parametric reduced order models that are valid over the desired parameter range without the need to redo the reduction when design parameters are changed. Numerical examples of a dielectric loaded rectangular waveguide and a microstrip line are provided illustrating the validity of the proposed method. View full abstract»

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  • Electromagnetic Closed-Surface Criterion for the 3-D Precise Integration Time-Domain Method for Solving Maxwell's Equations

    Publication Year: 2008 , Page(s): 2859 - 2874
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (840 KB) |  | HTML iconHTML  

    In order to derive the linear relations for solving the singular matrix problem during the recurrence process of the precise integration time-domain method, an electromagnetic closed-surface criterion is presented in orthogonal curvilinear coordinates. Such a criterion leads to the versatile method by which the spatial distributions of the linearly dependent field components are determined. It makes the complicated derivation for linear relation, usually depending on experience, regular, and therefore improves the general-purpose property of the method. With such a criterion, linear relations have been obtained in the computational domain, on the absorbing boundaries and on the edges where boundaries cross in orthogonal curvilinear coordinates. Numerical examples indicate the validity of the criterion. View full abstract»

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  • A Symmetric Electromagnetic-Circuit Simulator Based on the Extended Time-Domain Finite Element Method

    Publication Year: 2008 , Page(s): 2875 - 2884
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (987 KB) |  | HTML iconHTML  

    A symmetric hybrid electromagnetic-circuit simulator based on the extended time-domain finite element method (FEM) is presented for the simulation of microwave devices embedded with linear/nonlinear lumped circuits. The distributive portion of the device is modeled by the time-domain FEM to generate an electromagnetic subsystem, while the embedded lumped circuits are analyzed by a SPICE-like transient circuit solver to generate a circuit subsystem. A symmetric global system for both the electromagnetic and circuit unknowns is then established by combining the two fully discretized subsystems through coupling matrices to model their interactions. For active devices, the resulting global electromagnetic-circuit system usually includes nonlinear equations, and thus is solved by a solution algorithm carefully designed to handle nonlinearity. The proposed simulator significantly extends the capability of the existing time-domain finite element solver to model more complex and active devices such as microwave amplifiers. Numerical examples are presented to validate the algorithm and demonstrate its accuracy and applications. View full abstract»

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  • On the Coupling Integrals Arising in the Method of Moments Formulation of Laterally Bounded Structures

    Publication Year: 2008 , Page(s): 2885 - 2892
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (790 KB) |  | HTML iconHTML  

    A generic integral equation and method of moments formulation is presented for laterally bounded stratified media including planar metallization. The main asset of the developed approach is its flexibility, as it encompasses generic lateral boundary conditions and explicitly applies to any linear subsectional basis functions with constant surface divergence. This includes the rooftop functions on rectangular and triangular supports currently proposed in standard method of moment meshers. This approach provides closed expressions for the coupling integrals appearing in the method of moments matrix elements. These formulas are based of Green's functions modal expansions and in the possibility, conclusively demonstrated in this paper to transform the surface integrals into contour integrals allowing an efficient and systematic implementation of the procedure. Full derivations are presented for several lateral boundary conditions, including rectangular and circular metallic cavities and periodic structures. Numerical examples including the analysis of real-life planar boxed circuits are presented. In all cases the obtained results compare favourably with other existing techniques. View full abstract»

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The IEEE Transactions on Microwave Theory and Techniques focuses on that part of engineering and theory associated with microwave/millimeter-wave components, devices, circuits, and systems involving the generation, modulation, demodulation, control, transmission, and detection of microwave signals. This includes scientific, technical, and industrial, activities. Microwave theory and techniques relates to electromagnetic waves usually in the frequency region between a few MHz and a THz; other spectral regions and wave types are included within the scope of the Society whenever basic microwave theory and techniques can yield useful results. Generally, this occurs in the theory of wave propagation in structures with dimensions comparable to a wavelength, and in the related techniques for analysis and design..

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