By Topic

Microwave Theory and Techniques, IEEE Transactions on

Issue 11 • Date Nov. 2007

Filter Results

Displaying Results 1 - 25 of 28
  • Table of contents

    Page(s): C1 - C4
    Save to Project icon | Request Permissions | PDF file iconPDF (47 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Microwave Theory and Techniques publication information

    Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (41 KB)  
    Freely Available from IEEE
  • Mildly Nonquasi-Static Two-Port Device Model Extraction by Integrating Linearized Large-Signal Vector Measurements

    Page(s): 2277 - 2289
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1736 KB) |  | HTML iconHTML  

    This paper introduces a new procedure, based on linearized large-signal vector measurements, for extracting a nonlinear behavioral model for two-port active microwave devices. The technique is applied to a model structure that assumes a short-term memory condition and is formulated as a parallel connection of a limited number of frequency-weighted static nonlinearities. The proposed method consists of integrating the time-varying linear characterization of the device driven into a nonlinear state by a large signal. The experiment design and measurement setup are based on a large-signal network analyzer and are discussed in detail. In the second portion of this paper, insight is provided on the most meaningful model parameters, along with an extensive independent experimental validation, which considers a GaAs pHEMT as a case study and includes two-tone large-signal data, a wideband code division multiple access signal, bias-dependent -parameters, and dc data. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Behavioral Thermal Modeling for Microwave Power Amplifier Design

    Page(s): 2290 - 2297
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1208 KB) |  | HTML iconHTML  

    System-level models simplify the analysis of complex RF systems, such as transmission-reception modules, by expressing global input-output relationships. However, the development of high RF power models for nonlinear subsystems requires the prediction of the distortion induced by low-frequency memory effects such as self-heating effects. In this framework, we present a new electrothermal behavioral model for power amplifiers. This global model is based on the coupling between a behavioral electrical model derived from the transistor-level description of the amplifier and a thermal reduced model. This model, implemented into a circuit simulator, allows to predict the impact of the thermal effects in pulsed RF mode thanks to an envelope transient analysis. This approach has also been validated by measurements. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 3-D Integration of 10-GHz Filter and CMOS Receiver Front-End

    Page(s): 2298 - 2305
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (941 KB) |  | HTML iconHTML  

    A 10-GHz filter/receiver module is implemented in a novel 3-D integration technique suitable for RF and microwave circuits. The receiver designed and fabricated in a commercial 0.18-mum CMOS process is integrated with embedded passive components fabricated on a high-resistivity Si substrate using a recently developed self-aligned wafer-level integration technology. Integration with the filter is achieved through bonding a high-Q evanescent-mode cavity filter onto the silicon wafer using screen printable conductive epoxy. With adjustment of the input matching of the receiver integrated circuit by the embedded passives fabricated on the Si substrate, the return loss, conversion gain, and noise figure of the front-end receiver are improved. At RF frequency of 10.3 GHz and with an IF frequency of 50 MHz, the integrated front-end system achieves a conversion gain of 19 dB, and an overall noise figure of 10 dB. A fully integrated filter/receiver on an Si substrate that operates at microwave frequencies is demonstrated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of Cryogenic SiGe Low-Noise Amplifiers

    Page(s): 2306 - 2312
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1487 KB) |  | HTML iconHTML  

    This paper describes a method for designing cryogenic silicon-germanium (SiGe) transistor low-noise amplifiers and reports record microwave noise temperature, i.e., 2 K, measured at the module connector interface with a 50-Omega generator. A theory for the relevant noise sources in the transistor is derived from first principles to give the minimum possible noise temperature and optimum generator impedance in terms of dc measured current gain and transconductance. These measured dc quantities are then reported for an IBM SiGe BiCMOS-8HP transistor at temperatures from 295 to 15 K. The measured and modeled noise and gain for both a single-and two-transistor cascode amplifier in the 0.2-3-GHz range are then presented. The noise model is then combined with the transistor equivalent-circuit elements in a circuit simulator and the noise in the frequency range up to 20 GHz is compared with that of a typical InP HEMT. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A New Compact Load Network for Doherty Amplifiers Using an Imperfect Quarter-Wave Line

    Page(s): 2313 - 2319
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1361 KB) |  | HTML iconHTML  

    In this paper, we propose a new compact load network for high-power Doherty amplifiers using an imperfect quarter-wave line. A compact pi-network quarter-wave transmission line, which consisted of two shunt capacitors and a series microstrip line, was used to replace a bulky microstrip transmission line. A simple L-C matching network was then deployed after the quarter-wave line. To take the inherent internal parasitic components in the packaged high-power transistors into account, the shunt capacitors of the pi-network quarter-wave transmission line were readjusted, which made an imperfect quarter-wave line. For verification, both the conventional and compact Doherty amplifiers were designed and implemented for the 859-MHz band using high-voltage laterally diffused metal-oxide-semiconductor field-effect transistors. The measured linearities and efficiencies of both amplifiers were compared to each other with respect to the reference performance of the class-AB amplifier for two-tone and down-link wideband code-division multiple-access signal excitations. The compact Doherty amplifier with a significantly reduced size for the load network by 75.7% performed even better than the conventional Doherty amplifier. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Linearization of CMOS Broadband Power Amplifiers Through Combined Multigated Transistors and Capacitance Compensation

    Page(s): 2320 - 2328
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (873 KB) |  | HTML iconHTML  

    We present the development of a device-level linearization technique and its applications in broadband power amplifiers (PAs). The proposed topology firstly combines derivative transconductance superposition method and gate capacitance compensation technique, and creates a "sweet region" for suppressing third-order intermodulation (IM3) without the penalty of large power consumption. The effectiveness of the proposed technique has been demonstrated through a fully integrated distributed amplifier. The experimental results in 0.18-mum RF CMOS technology show that IM3 is improved by 11 dB. The achievable power-added efficiency is up to 25%, which is the highest among the broadband CMOS PAs reported thus far. The amplifier achieves a measured 3-dB bandwidth of 3.7-8.8 GHz, and a gain of 8.24 dB. The amplifier only consumes 154-mW dc power, and the measured saturation power (Psat) is 19 dBm. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Demonstration of a 311-GHz Fundamental Oscillator Using InP HBT Technology

    Page(s): 2329 - 2335
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (879 KB) |  | HTML iconHTML  

    In this paper, a sub-millimeter-wave HBT oscillator is reported. The oscillator uses a single-emitter 0.3 m15 m InP HBT device with maximum frequency of oscillation greater than 500 GHz. The passive components of the oscillator are realized in a two metal process with benzocyclobutene used as the primary transmission line dielectric. The oscillator is implemented in a common base topology due to its inherent instability. The design includes an on-chip resonator, output matching circuitry, and injection locking port. A free-running frequency of 311.6 GHz has been measured by down-converting the signal. Additionally, injection locking has been successfully demonstrated with up to 17.8 dB of injection-locking gain. This is the first fundamental HBT oscillator operating above 300 GHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Some Properties of Generalized Scattering Matrix Representations for Metallic Waveguides With Periodic Dielectric Loading

    Page(s): 2336 - 2344
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (629 KB) |  | HTML iconHTML  

    Some new results are presented on the properties of generalized scattering matrix representations for metallic waveguides with axially periodic dielectric loadings. A unified framework is given for describing the frequency dependence and for identifying the emergence of propagating, nonpropagating, and complex Floquet modes in single mode, as well as multimode, regions. Two new conservation relations are formulated for the generalized scattering matrix of the unit cell in lossless periodic structures. One of these relations provides a convenient means for checking the correctness of the values of calculated matrix elements, while the other relation yields accurate estimates for the stopband-passband transition frequencies located within single Floquet-mode regions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power Transfer in a Large Parallel Array of Coupled Dielectric Waveguides

    Page(s): 2345 - 2353
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1260 KB) |  | HTML iconHTML  

    This paper presents a compact analytical solution to the conventional coupled-mode equations for a large parallel coupled array of identical dielectric waveguides. Such arrays could be used as couplers in millimeter-wave or fiber-optic communication. The approach here is to characterize the array response to a signal injected into single waveguide first. This approach drastically simplifies the double Fourier sums called for in dealing with multiple waveguide injections. Regardless of the size of an array, the response consists of a series of Bessel functions, six of which suffice to give good accuracy. The general solution is then obtained by a linear superposition of responses when multiple waveguides are injected. Quasi-3-D profiles of waves propagating and spreading in a large array of 100 coupled guides can be quickly displayed using Microsoft Excel. Remarkably clear characteristics of power transfer such as self-focusing and boundary reflection are observed. Since the solution involves Bessel functions of high orders that diminish rapidly in value, the solution for very large arrays can be computed just as efficiently as for smaller arrays. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Generalized Impedance Boundary Condition for Conductor Modeling in Surface Integral Equation

    Page(s): 2354 - 2364
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (688 KB) |  | HTML iconHTML  

    A generalized impedance boundary condition is developed to rigorously model on-chip interconnects in the full-wave surface integral equation by a two-region formulation. It is a combination of the electric-field integral equation for the exterior region and the magnetic-field integral equation for the interior conductive region. The skin effect is, therefore, well captured. A novel integration technique is proposed to evaluate the Green's function integrals in the conductive medium. Towards tackling large-scale problems, the mixed-form fast multipole algorithm and the multifrontal method are incorporated. A new scheme of the loop-tree decomposition is also used to alleviate the low-frequency breakdown for the formulation. Numerical examples show the accuracy and reduced computation cost. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rigorous Mode-Matching Method of Circular to Off-Center Rectangular Side-Coupled Waveguide Junctions for Filter Applications

    Page(s): 2365 - 2373
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (805 KB) |  | HTML iconHTML  

    An accurate and efficient method for analyzing circular to multiple off-center rectangular side-coupled waveguide T-junctions is developed based on a rigorous mode-matching technique. The method is very general and not limited by symmetry or other dimensional constraints to the junction. A new way to match fields on the curved interface between subregions is described in detail. The computer code developed based on this theory is highly efficient. The numerical results match with the results obtained by other methods including experimental ones. The method is used to design a side-coupled circular waveguide dual-mode filter. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Passivity Enforcement With Relative Error Control

    Page(s): 2374 - 2383
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1015 KB) |  | HTML iconHTML  

    This paper introduces a new error control strategy in passivity enforcement schemes for linear lumped macromodels. We consider the general class of a posteriori passivity enforcement algorithms based on Hamiltonian matrix perturbation. Standard available formulations preserve the accuracy during passivity enforcement using special matrix norms associated to the controllability Gramian of the macromodel. This procedure leads to absolute error control. On the other hand, it is well known that relative error control in the macromodel is sometimes preferable, especially for structures that are characterized by small coupling coefficients or high dynamic range in their responses. Here, we present a frequency-weighting scheme leading to the definition of a modified Gramian that, when employed during passivity enforcement, effectively leads to relative error control. Several examples illustrate the reliability of the proposed technique. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Efficient Time-Domain Simulation Method for Multirate RF Nonlinear Circuits

    Page(s): 2384 - 2392
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (958 KB) |  | HTML iconHTML  

    This paper describes a new computer-aided design tool especially conceived for the efficient time-domain simulation of highly heterogeneous nonlinear wireless communication circuits, i.e., combining RF and baseband analog circuitry and digital components. Using multirate Runge-Kutta algorithms within a multi time framework, to benefit from the different rates of variation of slowly varying (latent) and fast-varying (active) currents and voltages (state variables), we managed to solve the envelope transient regime of circuits excited by AM and PM RF carriers, in a highly efficient way. Indeed, with the adoption of convenient sampling rates for the multiple time representations of the slowly varying and fast-varying state variables, gains of more than one order of magnitude in simulation time are reported, even for an illustrative circuit example of very small size. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of Bandpass Elliptic Filters Employing Inductive Windows and Dielectric Objects

    Page(s): 2393 - 2398
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1004 KB) |  | HTML iconHTML  

    In this paper, we propose an alternative configuration for the design of bandpass inductive filters using transversal topologies. The structure is based on the use of a dielectric post asymmetrically placed on a cavity resonator. The input and output windows will couple energy to the TE102-and TE103 -mode resonators at the same time, therefore obtaining the transversal topology. The proposed configuration is very compact, and allows to implement transmission zeros for maximum selectivity in an easy way. Results are validated with Ansoft's finite-element High Frequency Structure Simulator tool, and with an integral-equation technique to demonstrate the validity of the proposed structure. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A 25–75-MHz RF MEMS Tunable Filter

    Page(s): 2399 - 2405
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB) |  | HTML iconHTML  

    This paper presents a state-of-the-art discrete RF microelectromechanical systems (MEMS) tunable filter designed for 25-75-MHz operation. This paper also presents an enhanced model of the RF MEMS switch, which is used for accurate prediction of the tunable filter response. The two-pole lumped-element filter is based on digital capacitor banks with on-chip metal-contact RF MEMS switches and lumped inductors, and results in a tuning range of 3:1 with fine frequency resolution, and a return loss better than 13 dB for the entire tuning range. The relative bandwidth of the filter is 4 plusmn 1% over the tuning range and the insertion loss is 3-5 dB, limited mostly by the inductor Q and the switch loss. The IIP3 measurements prove that tunable filters with metal-contact series RF MEMS switches show extremely linear behavior (IIP3 > 68 dBm). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Dual-Band Coupled-Line Balun Filter

    Page(s): 2406 - 2411
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (818 KB) |  | HTML iconHTML  

    In this paper, a new type of device called dual-band coupled-line bandpass balun filter is presented. Based on the traditional coupled-line filter theory and Marchand balun configuration, a new device with both filter-type, as well as balun-type characteristics is proposed. The new device utilizes -type transmission-line stepped-impedance resonators to achieve a dual-band operation. Besides providing a simple design procedure for the device, its working mechanism is also revealed mathematically. A prototype balun filter operating at 2.4 and 5.8 GHz has been realized using traditional printed circuit board technology to validate the proposed concept and theory, showing promising application potentials for future multiband RF wireless transceiver modules. Experimental measurements show good agreement with analytical and computer simulations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Microstrip Ultra-Wideband Bandpass Filter With Cascaded Broadband Bandpass and Bandstop Filters

    Page(s): 2412 - 2418
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1173 KB) |  | HTML iconHTML  

    This paper develops a novel ultra-wideband bandpass filter by cascading a broadband bandpass filter with another broadband bandstop filter. Properly selected impedances of transmission lines achieve broadband bandpass and bandstop filters and make independent designs possible. Detailed design and synthesis procedures are provided; moreover, agreement between measured and theoretically predicted results demonstrates feasibility of the proposed filter. Due to its simple structure, the ultra-wideband bandpass filter newly introduced in this paper is suitable for integration in the single-chipped circuit or implementation on printed circuit boards. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Parallel-Strip Ring Power Divider With High Isolation and Arbitrary Power-Dividing Ratio

    Page(s): 2419 - 2426
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1290 KB) |  | HTML iconHTML  

    In this paper, a new power divider concept, which provides high flexibility of transmission line characteristic impedance and port impedance, is proposed. This power divider is implemented on a parallel-strip line, which is a balanced transmission line. By implementing the advantages and uniqueness of the parallel-strip line, the divider outperforms the conventional divider in terms of isolation bandwidths. A swap structure of the two lines of the parallel-strip line is employed in this design, which is critical for the isolation enhancements. A lumped-circuit model of the parallel-strip swap including all parasitic effects has been analyzed. An equal power divider with center frequency of 2 GHz was designed to demonstrate the idea. The experimental results show that the equal power divider has 96.5% -10-dB impedance bandwidth with more than 25-dB isolation and less than 0.7-dB insertion loss. In order to generalize the concept with an arbitrary power ratio, we also realize unequal power dividers with the same isolation characteristics. The impedance bandwidth of the proposed power divider will increase with the dividing ratio, which is opposite to the conventional Wilkinson power divider. Unequal dividers with dividing ratios of 1 : 2 and 1 : 12 are designed and measured. Additionally, a frequency independent 180 power divider has been realized with less than 2 phase errors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Slow-Wave Line Coupler With Interdigital Capacitor Loading

    Page(s): 2427 - 2433
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1543 KB) |  | HTML iconHTML  

    In this study, a full-wave-based circuit model of an interdigital capacitor in the form of a coplanar waveguide (CPW) configuration is studied by using numerical thru-reflect-line calibration techniques, which can easily be combined with commercial electromagnetic simulation software. Subsequently, a slow-wave line coupler is proposed and realized for size miniaturization by loading different interdigital capacitors onto a coupled CPW line, which has equal phase velocities for both odd and even modes. An experimental prototype is fabricated, and measured results show a good agreement with simulated ones, thereby demonstrating an excellent performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Symmetrical Four-Port Microstrip Coupler for Crossover Application

    Page(s): 2434 - 2438
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (370 KB) |  | HTML iconHTML  

    A symmetrical four-port microstrip coupler has been proposed for crossover application. Models have also been developed to provide insight into the performance of such a coupler, which is based on the double-ring design. Laboratory tests have confirmed that the measured isolation and return loss of the prototype coupler exceed 20 dB over a bandwidth of 20% (from 0.92 to 1.12 GHz). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modified Wilkinson Power Dividers for Millimeter-Wave Integrated Circuits

    Page(s): 2439 - 2446
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (877 KB) |  | HTML iconHTML  

    A modification of the Wilkinson power divider is presented that eases planar implementation while maintaining performance. By adding transmission lines between the resistor and the quarter-wave transformers of the traditional design, a range of valid solutions exists that meet the conditions of being reciprocal, isolated between the output ports, and matched at all ports. The proposed design is particularly useful at millimeter-wave frequencies where reduced physical dimensions make a circuit configuration suitable for low-cost package-level implementation difficult using traditional methods. Two frequency bands are demonstrated. At V-band, the circuit gives 0.3-dB excess insertion loss, 19-dB isolation, and 50% bandwidth. At the W-band, the circuit gives 0.75-dB excess insertion loss, 24-dB isolation, and 39% bandwidth. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inverse Synthetic Aperture Secondary Radar Concept for Precise Wireless Positioning

    Page(s): 2447 - 2453
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1232 KB) |  | HTML iconHTML  

    In this paper, the novel inverse synthetic aperture secondary radar wireless positioning technique is introduced. The proposed concept allows for a precise spatial localization of a backscatter transponder even in dense multipath environments. A novel secondary radar signal evaluation concept compensates for the unknown modulation phase of the returned signal and thus leads to radar signals comparable to common primary radar. With use of this concept, inverse synthetic aperture radar algorithms can be applied to the signals of backscatter transponder systems. In simulations and first experiments, we used a broadband holographic reconstruction principle to realize the inverse synthetic aperture approach. The movement of the transponder along a short arbitrary aperture path is determined with assisting relative sensors (dead reckoning or inertia sensors). A set of signals measured along the aperture is adaptively focused to the transponder position. By this focusing technique, multipath reflections can be suppressed impressively and a precise indoor positioning becomes feasible. With our technique, completely new and powerful options for integrated navigation and sensor fusion in RF identification systems and wireless local positioning systems are now possible. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Using a priori Data to Improve the Reconstruction of Small Objects in Microwave Tomography

    Page(s): 2454 - 2462
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1138 KB) |  | HTML iconHTML  

    A study is presented where the use of dielectric a priori data in the reconstruction algorithm for microwave tomography is investigated. A new algorithm has been developed that includes the a priori dielectric data in the reconstruction process. This development is made as an extension to a conventional conjugate-gradient reconstruction algorithm. This paper further contains a numerical study of the new algorithm where the results indicate that by taking the a priori data into account, the accuracy and ability to resolve small objects can significantly be improved. This study was motivated by the development of an application for biomedical microwave imaging where it is investigated how knowledge of the tissue properties being imaged potentially can be used to improve the accuracy in the reconstruction. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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..

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Dominique Schreurs
Dominique.Schreurs@ieee.org

Editor-in-Chief
Jenshan Lin
jenshan@ieee.org