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Microwave Theory and Techniques, IEEE Transactions on

Issue 6 • Date June 2006

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  • [Front cover]

    Page(s): c1
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  • IEEE Transactions on Microwave Theory and Techniques publication information

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  • Table of contents

    Page(s): 2565 - 2566
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  • Guest editorial

    Page(s): 2567
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  • A novel technique for complex permittivity measurement based on a planar four-port device

    Page(s): 2568 - 2575
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    A novel technique for the measurement of the complex permittivity of materials is presented that overcomes many limitations of the conventional measurement methods. The RF signal transmitted through a transmission line loaded with the material under test is combined with a reference signal using a quadrature hybrid in such a way that the complex permittivity can be measured by simply detecting the two output amplitudes. This technique requires a simple calibration procedure, provides good accuracy, and avoids expensive vector measurements, thus combining the advantages of transmission methods, in terms of good accuracy, with those of resonant methods, in terms of scalar measurements. Two microstrip implementations have been realized for measurements at 2.35 and 10 GHz, showing very good accuracy to be achieved in both frequency ranges. The measured permittivities have been compared with those obtained with a resonant and transmission method and with data from literature, resulting in a very good agreement for both epsivr and tandelta View full abstract»

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  • A novel wideband MMIC voltage controlled attenuator with a bandpass filter topology

    Page(s): 2576 - 2583
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    The theory, analysis, and systematic design guidelines for a novel wideband monolithic bandpass pi-network voltage controlled attenuator (VCA) are presented. A 24-32-GHz VCA was designed and manufactured using 0.15-mum GaAs pseudomorphic high electron-mobility transistor (pHEMT) technology. This is the first reported VCA to use a bandpass filter topology to achieve the required operating frequency band and eliminate the effects of parasitic capacitances of the pHEMTs. The bandpass filter absorbs the parasitic capacitances and thereby eliminates their detrimental effects. The measured attenuation dynamic range is 12 dB plusmn 0.5 dB with minimum insertion loss of 2-3 dB. The input power handling capability is up to 0 dBm. The VCA is well matched and may be placed in a 50-Omega system View full abstract»

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  • A novel electronically tunable active duplexer for wireless transceiver applications

    Page(s): 2584 - 2592
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    In this paper, a novel electronically tunable active duplexer suitable for reconfigurable wireless transceiver applications is presented. The theory, design, and measured results of a varactor tunable active duplexer are summarized. The prototype active duplexer presented in this paper provides an electronically adjustable isolation of 20-50 dB between isolated ports and a gain of approximately 5 dB between coupled ports in the tunable range from 1.62 to 1.82 GHz in both transmit and receive modes of operations. The measured noise figure of the duplexer varied from 1.77 to 2.44 dB in the tuning range. The measured output powers at the 1-dB gain compression point and third-order intercept point, varied from 8.5 to 9.5 dBm and 20 to 29.5 dBm, respectively, in the tuning range. The design guidelines, measured S-parameters, and results of yield analysis of the duplexer are presented. The proposed duplexer can be implemented as a monolithic microwave integrated circuit View full abstract»

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  • High gain active microstrip antenna for 60-GHz WLAN/WPAN applications

    Page(s): 2593 - 2603
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    A 60-GHz active microstrip antenna design comprising a three-stage pseudomorphic high electron mobility transistor amplifier integrated with a high gain antenna on an alumina substrate is presented. The amplifier has 18-dB gain and is ribbon bonded to the substrate on which the antenna is defined. The antenna is a microstrip array antenna with a simple etched pattern for producibility at high frequencies. Two antenna layouts are designed, for different coverage areas: a single array having 13.4-dBi directivity and a double array with 14.6-dBi directivity. Antenna losses are approximately 1-2 dB, giving antenna gains of about 12 and 13 dBi, respectively. Mechanical simplicity is achieved with this design, and unnecessary transitions are avoided. Measurements are performed on amplifier and antenna separately, as well as on the integrated design. Amplifier chips with and without benzocyclobutene passivation are fabricated and measured for comparison View full abstract»

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  • Neural-network-based parasitic modeling and extraction verification for RF/millimeter-wave integrated circuit design

    Page(s): 2604 - 2614
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    This paper reports an interconnect modeling approach for RF and millimeter-wave integrated circuits (ICs) using neural network models and a novel parasitic extraction verification procedure using automatically generated test structures. The effects of the parasitics in RF/millimeter-wave ICs are investigated with special focus on the parasitic inductances, since they are not evaluated by most of the commercially available extraction tools. State-of-the-art silicon-based multilayer RF process parameters are utilized to extract the resistive, the capacitive, and the inductive components of the layout interconnects. Neural network models are developed using electromagnetic (EM) simulation results of a set of passive interconnect structures. In addition, an automated layout generation methodology is used for the verification of the parasitic extraction methodologies. The proposed verification approach is demonstrated using automatically generated passive test structures and ring oscillators. The effects of parasitics are also investigated in voltage-controlled oscillators (VCOs) and amplifiers for millimeter-wave applications, and the neural models are verified using 30-GHz VCO measurement results. Hence, we present a complete modeling report of layout interconnect parasitics in RF/millimeter-wave integrated circuits as well as a novel verification procedure to validate non-EM analytical or neural models View full abstract»

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  • Modeling of 3-D periodic multiphase composites by homogenization

    Page(s): 2615 - 2619
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    An efficient technique is proposed for analyzing two- and three-dimensional lossy periodic composite materials, combining an asymptotic multiscale method with the unfolding method. The computed effective conductivities for square cylinders and cubes suspended in a host isotropic medium are compared to the Maxwell-Garnett mixing formula predictions. The electromagnetic field in a finite lattice of round cylinders is compared with the exact electromagnetic field calculated directly in the heterogeneous lattice View full abstract»

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  • LTCC 3-D resonators applied to the design of very compact filters for Q-band applications

    Page(s): 2620 - 2627
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    We propose a new low-temperature co-fired ceramic (LTCC) U-shaped resonator. The advantages of LTCC technology are employed to design this three-dimensional (3-D) lambdag/2 resonator. The latter is modeled and optimized by 3-D electromagnetic simulations and is validated by experimental results. In order to validate the coupling between these resonators, a two-pole filter, functioning around 39 GHz, has then been designed and realized with success. Finally, two very compact three-pole bandpass filters have been conceived for a Q-band duplexer design. On the one hand, a filter has been designed around 38 GHz and presents a transmission zero in the upper band. On the other hand, an other filter functioning at 40.7 GHz is presented with a transmission zero in the lower band. Experimental results are in good agreement with theoretical ones View full abstract»

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  • Miniaturized microstrip and CPW filters using coupled metamaterial resonators

    Page(s): 2628 - 2635
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    In this paper, it is shown that the application of metamaterial resonators to the design of planar microwave filters provides a high level of miniaturization for such devices. Specifically, split-ring resonator, complementary split-ring resonator, and spiral resonator are used to synthesize microwave filters using the coupling coefficient approach. Some considerations in order to improve and control the coupling coefficients between resonators are exposed. The magnetic and electric character of the coupling coefficient is analyzed in detail, and a method to identify this coupling is proposed. Finally, several prototype device filters operative at S-band are provided to illustrate the proposed techniques View full abstract»

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  • Efficient numerical methods for simulation of high-frequency active devices

    Page(s): 2636 - 2645
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    We present two new numerical approaches for physical modeling of high-frequency semiconductor devices using filter-bank transforms and the alternating-direction implicit finite-difference time-domain method. In the first proposed approach, a preconditioner based on the filter-bank and wavelet transforms is used to facilitate the iterative solution of Poisson's equation and the other semiconductor equations discretized using implicit schemes. The second approach solves Maxwell's equations which, in conjunction with the semiconductor equations, describe the complete behavior of high-frequency active devices, with larger time-step size. These approaches lead to the significant reduction of the full-wave simulation time. For the first time, we can reach over 95% reduction in the simulation time by using these two techniques while maintaining the same degree of accuracy achieved using the conventional approach View full abstract»

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  • Distributed MEMS tunable matching network using minimal-contact RF-MEMS varactors

    Page(s): 2646 - 2658
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    This paper presents the design, fabrication, and measurement of a double-slug tunable matching network based on a distributed microelectromechanical-system (MEMS) transmission line. The tuner is implemented with a new minimal-contact RF-MEMS varactor that largely eliminates stiction while allowing the capacitance ratio to be set anywhere from 2 to 5. The measured performance of the tunable matching network demonstrates complete coverage of the Smith chart out to a maximum voltage standing-wave ratio of 12:1 from 10 to 30 GHz with excellent agreement between measurement and simulation results View full abstract»

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  • A corrected microwave multisine waveform generator

    Page(s): 2659 - 2664
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    This paper proposes a solution for one of the major difficulties associated with arbitrary waveform generation at microwave frequencies: the nonideal RF circuits used for signal generation. It presents a practical implementation of a RF multisine signal generator that corrects for the linear and nonlinear impairments identified with its output RF circuitry. The integration of an adaptive predistortion algorithm with a previously presented methodology for multisine synthesis with prescribed higher-order statistics, proved the feasibility of a simple microwave arbitrary waveform generator that meets the aims of previously developed signal synthesis theory View full abstract»

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  • Tunable metamaterial transmission lines based on varactor-loaded split-ring resonators

    Page(s): 2665 - 2674
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    In this paper, it is demonstrated that varactor-loaded split-ring resonators (VLSRRs) coupled to microstrip lines can lead to metamaterial transmission lines with tuning capability. Both negative permeability (mu<0) and double (or left-handed) negative media have been designed and fabricated with tuning ranges as wide as 30%. The negative effective permeability is provided by the VLSRRs in a narrow band above their resonant frequency, which can be bias controlled by virtue of the presence of diode varactors. To achieve a negative effective permittivity in the left-handed structure, metallic vias emulating shunt inductances are periodically placed between the conductor strip and the ground plane. The lumped-element equivalent-circuit models of the designed structures have been derived. It has been found that these models provide a good qualitative description of device performance. Since the VLSRR microstrip line and the line loaded with both VLSRRs and vias exhibit stopband and bandpass behavior, respectively, the ideas presented in this study can be applied to the design of narrowband tunable frequency-selective structures with compact dimensions. This is the first time that a tunable left-handed transmission line, based on SRRs, is proposed View full abstract»

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  • Behavior of a traveling-wave amplifier versus temperature in SOI technology

    Page(s): 2675 - 2683
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    In this paper, the design and measurement results of a CMOS partially depleted silicon-on-insulator (SOI) traveling-wave amplifier (TWA) are presented. The four-stage TWA is designed with a single common source nMOSFET in each stage using a 130-nm SOI CMOS technology requiring a chip area of 0.75 mm2. A gain of 4.5 dB and a unity-gain bandwidth of 30 GHz are measured at 1.4-V supply voltage for a power consumption of 66 mW. The designed circuit has been characterized over a temperature range from 25 degC to 300 degC. The performance degradation on the gain of the TWA, the SOI transistors, as well as the microstrip lines used for the matching network are analyzed. Thanks to the introduction of a dynamic threshold-voltage MOSFET, a greater gain-bandwidth product under lower bias conditions is demonstrated View full abstract»

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  • Lumped-element load-network design for class-E power amplifiers

    Page(s): 2684 - 2690
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    This paper presents a design-oriented analysis of two lumped-element load-coupling topologies, which can be used to approximate class-E switching conditions. The presented output circuits are compared theoretically and experimentally with respect to harmonic termination and component values. Using a commercial BiCMOS process, two monolithic integrated class-E power amplifiers (PAs) have been designed and fabricated for operation at 5-6 GHz based on these load-coupling circuits. The PAs show an output power of over 19.7 dBm and power-added efficiency greater than 43.6% when operated from a 3-V supply. The results obtained with these first prototypes, operating at C-band, show the feasibility of the proposed lumped-element class-E networks View full abstract»

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  • Direct-conversion quadrature modulator MMIC design with a new 90/spl deg/ phase shifter including package and PCB effects for W-CDMA applications

    Page(s): 2691 - 2698
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    This paper presents a wideband code-division multiple-access direct-conversion quadrature modulator monolithic-microwave integrated-circuit (MMIC) design that employs a new technique to generate the 90deg phase shift with low implementation loss. From the bare-chip measurement, this new 90deg phase shifter has been proven with an amplitude and phase error less than 0.6 dB and 0.8deg, respectively, within the applied frequency range from 1.85 to 1.98 GHz. The package and printed circuit board (PCB) interconnects are also analyzed using the three-dimensional electromagnetic simulation tool and transformed into the equivalent-circuit elements for co-simulation with the designed quadrature modulator MMIC. The degradation of error vector magnitude and sideband suppression due to the package and PCB can be well predicted and verified by measurements. Although the proposed 90deg phase shifter has a remarkable advantage over the others in implementation loss, it is quite susceptible to the package and PCB effects and needs more design efforts to deal with those effects View full abstract»

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  • Multiwafer vertical interconnects for three-dimensional integrated circuits

    Page(s): 2699 - 2706
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    Low-loss multiwafer vertical interconnects appropriate for a microstrip-based circuit architecture are proposed. These transitions have been designed, fabricated, and measured for 100-mum-thick silicon and GaAs substrates separately. Experimental results show excellent performance up to 20 GHz, with extremely low insertion loss (better than 0.12 and 0.38 dB for the two different silicon designs and 0.2 dB for the GaAs transition), and very good return loss (reflection of better than 12.9 and 17.3 dB for the two silicon designs, respectively, and 13.6 dB for the GaAs design). Using a high-performance transition allows for a more power-efficient interconnect, while it enables denser packaging by stacking the substrates on top of each other, as today's technologies demand View full abstract»

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  • Power amplifier characterization: an active load-pull system based on six-port reflectometer using complex modulated carrier

    Page(s): 2707 - 2712
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    An original measurement system for nonlinear RF power-transistor characterization is presented. This new setup enables measurement and optimization of output power, power-added efficiency (PAE), or linearity using active fundamental tuning and six-port reflectometers as vector network analyzers. High- and low-frequency bias-tees are inserted at both ports of transistors in order to control source and load impedances at the baseband (envelope) frequency. Experimental results at 1.575 GHz show an adjacent channel power ratio improvement of 20 dB for a commercial GaAs MESFET power transistor operating in class AB. Moreover, the output power and PAE are increased by 1 dB and ten points, respectively View full abstract»

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  • A C-band high-efficiency second-harmonic-tuned hybrid power amplifier in GaN technology

    Page(s): 2713 - 2722
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    In this paper, the design, fabrication, and test of high-efficiency, high-power C-band harmonic-tuned power amplifiers in GaN technology is reported. The amplifier has been designed utilizing second-harmonic tuning for high-efficiency operation, thus exploiting the high-breakdown voltage peculiarity of GaN-based devices. Realized in a hybrid form, the amplifier has been characterized in terms of small-signal, power, and intermodulation (IMD) performance. An operating bandwidth over 20% around 5.5 GHz, with 33-dBm minimum output power, and 60% drain efficiency at center frequency is demonstrated, together with low IMD View full abstract»

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  • Broadband high-efficiency linearly and circularly polarized active integrated antennas

    Page(s): 2723 - 2732
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    This paper presents the design, fabrication, and measurements of two broadband high-efficiency active integrated antennas (AIAs) operating in linear polarization and circular polarization, respectively. A new design method is proposed for designing the broadband load network of the class-E power amplifier (PA), so that a high power-added efficiency (PAE) can be achieved over a broad bandwidth. A broadband high-efficiency class-E PA is designed based on the proposed method. The linearly polarized (LP) AIA is realized by integrating the broadband class-E PA with a broadband LP antenna, which uses a ring-slot coupled microstrip patch antenna. Then, the circularly polarized (CP) AIA is realized by integrating the broadband class-E PA with a broadband CP antenna, which uses a single-feed cross-slot-coupled microstrip patch antenna. Each antenna is designed for working as both a radiator and a harmonics-terminated load. A low-cost printed-circuit-board technology is employed in fabrication, and a p-high-electron mobility transistor is used. The PAE of the LP AIA is over 50% within a 14.6% bandwidth from 1.78 to 2.06 GHz, while the PAE of the CP AIA is over 50% within a 14% bandwidth from 1.92 to 2.21 GHz. The axial ratio of the CP AIA is below 3 dB over a 9% bandwidth from 1.99 to 2.18 GHz View full abstract»

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  • Miniaturized antenna arrays using decoupling networks with realistic elements

    Page(s): 2733 - 2740
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    In ordinary antenna arrays, the spacing between radiators is usually chosen lambda/2. In order to use antenna arrays in small mobile platforms, the overall dimensions and, hence, the radiator separation, must be reduced, which aggravates the problem of mutual coupling between radiators. Results are highly distorted beam patterns and greatly reduced radiation efficiency. We propose a method to design a decoupling and matching network for a three-element antenna array with a radiator separation of lambda/10, which additionally allows arbitrary beam patterns assigned to each port-subject to certain constraints. An iterative process is employed to account for network losses, which are unavoidable in any realistic network implementation View full abstract»

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  • Novel source of the chaotic microwave radiation based on the gyro-backward-wave oscillator

    Page(s): 2741 - 2744
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    First experimental studies of the nonstationary phenomena in a powerful K-band gyro-backward-wave oscillator with an external reflector are presented. Variation of the self-modulation frequency from 69 to 112 MHz and transition to the chaotic oscillations with spectrum width of 100 MHz were obtained due to the tuning of the guiding magnetic field. These results are in a good agreement with simulations, which demonstrate a strong dependence of the system dynamics on the strength of the magnetic field View full abstract»

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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
Dominique Schreurs
Dominique.Schreurs@ieee.org

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