# IEEE Transactions on Microwave Theory and Techniques

## Volume 56 Issue 12  Part 1 • Dec. 2008

This issue contains several parts.Go to:  Part 2

## Filter Results

Displaying Results 1 - 25 of 45

Publication Year: 2008, Page(s):C1 - C4
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• ### 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 (26)
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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 min... View full abstract»

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

Publication Year: 2008, Page(s):2692 - 2700
Cited by:  Papers (22)
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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 covaria... View full abstract»

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

Publication Year: 2008, Page(s):2701 - 2708
Cited by:  Papers (41)  |  Patents (1)
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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... View full abstract»

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

Publication Year: 2008, Page(s):2709 - 2716
Cited by:  Papers (24)  |  Patents (1)
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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... View full abstract»

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

Publication Year: 2008, Page(s):2717 - 2725
Cited by:  Papers (33)
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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 rep... View full abstract»

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

Publication Year: 2008, Page(s):2726 - 2733
Cited by:  Papers (31)
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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 ba... View full abstract»

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

Publication Year: 2008, Page(s):2734 - 2741
Cited by:  Papers (20)  |  Patents (1)
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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. ... View full abstract»

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

Publication Year: 2008, Page(s):2742 - 2747
Cited by:  Papers (43)
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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 anten... View full abstract»

• ### 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 (12)  |  Patents (1)
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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... View full abstract»

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

Publication Year: 2008, Page(s):2754 - 2763
Cited by:  Papers (22)  |  Patents (1)
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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 induc... View full abstract»

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

Publication Year: 2008, Page(s):2764 - 2770
Cited by:  Papers (7)
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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 un... View full abstract»

• ### 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 (127)
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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 stando... View full abstract»

• ### 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 (14)
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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 po... View full abstract»

• ### Electrically Tunable Antenna Design Procedure for Mobile Applications

Publication Year: 2008, Page(s):2789 - 2797
Cited by:  Papers (41)
| | PDF (1506 KB) | HTML

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 ... View full abstract»

• ### 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 (6)
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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... View full abstract»

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

Publication Year: 2008, Page(s):2808 - 2814
Cited by:  Papers (10)
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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 sy... View full abstract»

• ### 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 (20)
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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 comp... View full abstract»

• ### 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 (86)
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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 eliminat... View full abstract»

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

Publication Year: 2008, Page(s):2838 - 2850
Cited by:  Papers (2)
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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... View full abstract»

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

Publication Year: 2008, Page(s):2851 - 2858
Cited by:  Papers (7)
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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 t... View full abstract»

• ### 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)
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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 mak... View full abstract»

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

Publication Year: 2008, Page(s):2875 - 2884
Cited by:  Papers (27)
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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 trans... View full abstract»

• ### 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)
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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 ... View full abstract»

## Aims & Scope

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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## Meet Our Editors

Editor-in-Chief
Luca Perregrini
luca.perregrini@unipv.it

Editor-in-Chief
Jose Carlos Pedro
edit.tmtt@ua.pt