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Microwave Theory and Techniques, IEEE Transactions on

Issue 4  Part 1 • Date April 2009

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Displaying Results 1 - 25 of 27
  • Table of contents

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

    Page(s): C2
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  • Scalable Small-Signal and Noise Modeling for Deep-Submicrometer MOSFETs

    Page(s): 737 - 744
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (648 KB) |  | HTML iconHTML  

    A new scalable noise and small-signal model for deep-submicrometer metal-oxide semiconductor field-effect transistors, which consist of multiple elementary cells is presented in this paper. It allows exact modeling of all noise and small-signal model parameters from elementary cell to large-size device. The scalable rules for noise and small-signal model parameters are given in detail. The experimental and theoretical results show that at same bias condition, good scaling of the noise, and small-signal model parameters can be achieved between the large-size devices and elementary cell. Model verification is carried out by comparison of measured and simulated S-parameters and noise parameters. Good agreement is obtained between the measured and modeled results for 4 times 0.6 times 18 mum, 8 times 0.6 times 12 mum, and 32 times 0.6 times 2 mum gatewidth (number of gate fingers times unit gatewidth times cells) 90 nm gatelength MOSFETs. View full abstract»

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  • Extended Hammerstein Behavioral Model Using Artificial Neural Networks

    Page(s): 745 - 751
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1359 KB) |  | HTML iconHTML  

    In this paper, a novel extended Hammerstein model is presented to accurately mimic the dynamic nonlinearity of wideband RF power amplifiers (RFPAs). Starting with a conventional Hammerstein model scheme, which fails to predict the behavior of the RFPA with short-term memory effects, two areas of improvements were sought and found to allow for substantial improvement. First, a polar feed-forward neural network (FFNN) was carefully chosen to construct the memoryless part of the model. The error signal between the output and the input signal of the memoryless sub-model was then filtered and then post-injected at the model output. This extra branch, when compared to the conventional Hammerstein scheme, allowed for an extra mechanism to account for the memory effects due to dispersive biasing network that was present otherwise. The excellent estimation capability of the polar FFNN together with the additional filtered error signal post-injection led to remarkable accuracy when modeling two different RFPAs both driven with four-carrier wideband code division multiple access signals. Despite its simple topology and identification procedure, the extended Hammerstein model demonstrated is capable in accurately predicting the dynamic AM/AM and AM/PM characteristics and the output signal spectrum of the RFPA under test. View full abstract»

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  • A Quasi-Four-Pair Class-E CMOS RF Power Amplifier With an Integrated Passive Device Transformer

    Page(s): 752 - 759
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1633 KB) |  | HTML iconHTML  

    A quasi-four-pair structure of an RF CMOS power amplifier (PA) is proposed. The structure is applied to a 1.8-GHz class-E CMOS PA for a global system for mobile communications with a 0.18-mum RF CMOS process. This allows a simple design, as well as a high output power. The transistor size issues of the cascode PA are also studied. An integrated passive device transformer is used as both a power combiner and a matching circuit of the power stage. The results show an output power of 33.4-33.8 dBm and a power-added efficiency of 47.4%-50% with a supply voltage of 3.3 V at a frequency range of 1.71-1.91 GHz. View full abstract»

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  • An Analytical Approach in Analysis of Local Oscillator Near-the-Carrier AM Noise Suppression in Microwave Balanced Mixers

    Page(s): 760 - 766
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    In this paper, a new formulation based on conversion matrix method is proposed to analyze ldquonear-the-carrier local ocillator (LO) noiserdquo down conversion to IF in microwave mixers. This method could be easily applied to analyze LO noise down conversion in any type of mixer. Practical results of this method have been compared with the envelope method and measurement results. It is shown that despite the conventional AM noise suppression in balanced mixers, the near-the-carrier LO noise suppression does not occur necessarily at the center frequency of hybrid in balanced mixers. AM noise suppression values are predicted precisely. View full abstract»

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  • Design Techniques for a Low-Voltage VCO With Wide Tuning Range and Low Sensitivity to Environmental Variations

    Page(s): 767 - 774
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1012 KB) |  | HTML iconHTML  

    This paper presents design techniques for a low-voltage voltage-controlled oscillator (VCO) with a wide tuning range and low sensitivity to process, voltage, and temperature (PVT) variations. For wide tuning range, a switched tuning scheme is employed coupled with voltage-boosting techniques in a manner that improves the quality factor and tuning range of a switched capacitor array. To minimize the design overhead required for a robust VCO, an adaptive body-biasing technique is proposed, which relaxes the startup constraint and increases the VCO's immunity to PVT variations. The proposed VCO is implemented in 0.18-mum CMOS technology and operates at 2.4 GHz. It achieves phase noise of - 117 dBc/Hz at 1-MHz offset and a tuning range 20% while consuming 365 muW of power. The figure-of-merit with the tuning range is -197 dBc/Hz, which is the lowest among recent state-of-the-art low-voltage VCOs. View full abstract»

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  • A New Concept of Open {\rm TE}_{011} Cavity

    Page(s): 775 - 783
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (623 KB) |  | HTML iconHTML  

    The confinement properties of the open structure formed crossing a circular waveguide perpendicular to a parallel-plate waveguide are discussed, highlighting the fundamental differences with respect to the common high-frequency resonators. The structure supports a TE011 mode that appears suited for millimeter- and submillimeter-wave applications. The experimental characterization of this mode in a configuration resonating at 281 GHz is described in detail. The observed resonance exhibits state-of-the-art performances. The properties of the TE011 mode are studied in terms of the geometry, calculating the mode chart and the related quality factor and power-to-field conversion efficiency. The mode chart is then determined for configurations including a sample holder, where one of the waveguides is filled with a low-loss dielectric material. In addition to excellent merit figures, the TE011 mode shows a relevant stability with respect to the geometrical imperfections and to the insertion of a sample holder. The obtained results demonstrate that the proposed single-mode resonator competes with the standard cavities in terms of performances, versatility, and simplicity. View full abstract»

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  • Uniform Ferrite-Loaded Open Waveguide Structure With CRLH Response and Its Application to a Novel Backfire-to-Endfire Leaky-Wave Antenna

    Page(s): 784 - 795
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1181 KB) |  | HTML iconHTML  

    A uniform ferrite-loaded open waveguide structure with composite right/left-handed (CRLH) response and its application to a novel backfire-to-endfire leaky-wave antenna are presented. The structure consists of a ferrite-filled rectangular waveguide open to free space at one of its small sides and biased perpendicularly to its large sides. Based on the fact that the leakage from the open side represents only a small perturbation in terms of guidance, an analytical dispersion relation for the approximately equivalent perfect magnetic conductor closed waveguide structure is derived. The unique dispersive properties of this structure, including its inherent CRLH balanced response (gapless nonzero group velocity transition between the left- and right-handed bands) and low-loss characteristics due to off-resonance operation, are extensively described, parametrically studied, and concretized by design guidelines. This theory is validated by both finite-element method and finite integration technique full-wave results and demonstrated experimentally. The leakage of the structure is exploited to build a full-space backfire-to-endfire scanning leaky-wave antenna, which is capable of both fixed-bias frequency scanning and fixed-frequency bias scanning, while being a perfectly uniform structure not requiring any chip tuning components. This feature, and its subsequent design simplicity, represents a fundamental advantage over previous CRLH metmaterial implementations. To the best of our knowledge, the proposed ferrite waveguide is the first and unique uniform structure exhibiting a CRLH response. View full abstract»

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  • A Hierarchical Electromagnetic-Circuit Technique for Statistical Analysis of RF Circuits in the Spectral Domain

    Page(s): 796 - 806
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1293 KB) |  | HTML iconHTML  

    Spectral domain statistical analysis of RF circuits, combining a circuit simulator, which models the circuit part and a full-wave field solver, which models the passive elements, is presented in this paper. This paper first illustrates the importance of the knowledge of correlation information in accurately modeling the probability density functions (PDFs) of eventual objective functions using a simple transmission line paradigm. Next, this paper looks at the statistical study of on-chip RF passives using the spiral inductor as an example. It is shown that larger process variations necessitate modeling by means of a quadratic response surface to preserve accuracy. This results in nonindependent non-Gaussian nonclosed-form PDFs for the equivalent-circuit parameters of the passives. This paper then proposes a hierarchical technique to perform statistical analysis of RF circuits based on y-parameter representation for the circuit and the passive element parts. The proposed technique obviates the need for optimization steps to derive the equivalent-circuit parameters for the electromagnetic objects and the need to compute the correlation matrix between the circuit equivalent elements, while maintaining accuracy. The proposed approach is illustrated for the statistical analysis of an RF amplifier and its differential version operating at 15.78 GHz. PDFs of various quantities of interest are derived and yield measures are computed. View full abstract»

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  • A Novel Transition-Included Multilayer Filter

    Page(s): 807 - 814
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1643 KB) |  | HTML iconHTML  

    A novel transition-included multilayer filter is proposed with the associated electromagnetically coupled transition from conductor-backed coplanar waveguide to stripline designed as a part of the bandpass filter. Specifically, a filter equivalent-circuit model is introduced with the transformer turn ratio to specify the impedance-transformation characteristic of the transition. The proposed transition-included multilayer filter is then designed by simultaneously taking both embedded stripline resonator circuits and associated transitions into consideration. Being designed along with the transition, the implemented filter occupies a size only half of the conventional filter while still achieving the same specifications. The implemented filter does not require bond wires or air bridges, thereby reducing the response shift caused by misalignment in fabrication. Finally, the measurement and simulation results are presented and good agreement between them is observed. View full abstract»

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  • Design Enhancement of Miniature Lumped-Element LTCC Bandpass Filters

    Page(s): 815 - 823
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1650 KB) |  | HTML iconHTML  

    We present a novel methodology for the design of miniature lumped element components embedded in a low-temperature co-fired ceramic (LTCC) package. The entire process, from initial schematic design, through individual element design, to complete device optimization is discussed. The design and fabrication of novel miniature lumped element LTCC filters is used to validate the proposed methodology. Commercial software tools are used to accurately model and simulate all aspects of the devices to ensure design success. In addition, the filters occupy only 0.03 lambda times 0.05 lambda times 0.004 lambda of a conventional low-permittivity LTCC substrate, which is among the smallest sizes reported. An advantage of these filters is that they use a true third-order topology with three multilayer L-C resonators, leading to superior stopband performance. For the first time, measured results are shown for two new bandpass filters targeted for global positioning system applications. Measured results are in good agreement with the simulations and show an insertion loss of 2.8 dB and a return loss of 21.3 dB at the center frequency of 1.64 GHz. View full abstract»

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  • Dual-Band Bandpass Filter With Improved Performance in Extended Upper Rejection Band

    Page(s): 824 - 829
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (816 KB) |  | HTML iconHTML  

    Stepped-impedance resonators with different dimensions are used to design bandpass filters with a dual-passband response, as well as good rejection levels in the extended upper stopband. To achieve the goal, the resonators are designed to have two identical leading resonant frequencies, but dispersed higher order ones to make spurious peaks have low levels and small bandwidths. The stopband is then extended and the rejection levels are enhanced by collocating transmission zeros with the unwanted peaks. The zeros are tuned by adjusting the coupling lengths of the coupled stages and sliding the tap positions of the dual-band transformers along the end resonators. Measured results of two experimental circuits show a rejection level of 30 dB up to more than eight times the first passband frequency can be obtained. The measured data have good agreement with the simulation. View full abstract»

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  • A Two-Pole Two-Zero Tunable Filter With Improved Linearity

    Page(s): 830 - 839
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (794 KB) |  | HTML iconHTML  

    Two miniaturized tunable filters with two zeros to result in sharp skirts were developed at 1.4-2.0 GHz on epsivr=6.15 substrate. The filters were built using single and back-to-back varactor diodes and compared for linearity characteristics. The single-diode filter has a 1-dB bandwidth of 5plusmn0.5% and an insertion loss of 2.5-1.8 dB. The back-to-back diode filter has a 1-dB bandwidth of 4.9 plusmn0.5% and an insertion loss of 2.9-1.25 dB (resonator Q of 56-125). The back-to-back diode filter was designed for improved linearity characteristics using two uniformly doped varactor diode and biased with a high impedance circuit. A detailed Volterra series analysis is done on the back-to-back diode including the effect of the bias network and diode mismatches. The measured IIP3 for the back-to-back diode tunable filter is 22-41 dBm depending on the bias voltage and is 13-15 dB better than the single-diode design. The power handling capabilities of both designs is explored using large-signal S 21 measurements. To our knowledge, these planar tunable filters represent state-of-the-art insertion loss and linearity characteristics performance with varactor diodes as the tuning elements. View full abstract»

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  • Compact Modeling and Comparative Analysis of Silicon-Chip Slow-Wave Transmission Lines With Slotted Bottom Metal Ground Planes

    Page(s): 840 - 847
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1471 KB) |  | HTML iconHTML  

    A compact modeling approach for silicon-chip slow-wave transmission lines with slotted bottom metal ground planes is studied and its limitations are presented. The modeling approach facilitates the calculation of the slow-wave transmission line parameters based upon the corresponding coplanar and grounded coplanar transmission-line parameters. The described analysis method is used for a comparative study of the slow-wave structures versus their coplanar and grounded coplanar reference structures. Floating bottom shield slow-wave transmission lines are then compared with their grounded bottom shield counterparts. The theoretical results are supported by electromagnetic simulations and by measurements up to 30 and 50 GHz. View full abstract»

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  • A Novel Wideband Common-Mode Suppression Filter for Gigahertz Differential Signals Using Coupled Patterned Ground Structure

    Page(s): 848 - 855
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1168 KB) |  | HTML iconHTML  

    A wideband and compact filter design for common-mode noise suppression in high-speed differential signals is proposed based on two U-shaped and one H-shaped coupled patterned ground structure. An equivalent model of three coupled LC resonators to predict the common-mode suppression characteristics is also developed with good agreement to the full-wave simulation and measurement result. A test sample is designed and fabricated on a standard printed circuit board (PCB). It is found the common-mode noise can be reduced by the filter over 15 dB from 3.6 to 9.1 GHz and over 75% of amplitude in the time domain. More important, the differential signal integrity, in terms of insertion loss and group delay in the frequency domain and eye diagrams in the time domain, is not degraded within the wide bandwidth. The fractional bandwidth of the stopband can reach 87% and the filter size is about 0.44 lambdag times 0.44 lambdag. The radiation caused by the common-mode current on the attached I/O cables is also efficiently suppressed by 10 dB on average within the designed stopband. To our best knowledge, it is the first low-cost common-mode filter designed for the gigahertz high-speed signals with the largest fractional bandwidth and most compact size on a PCB. View full abstract»

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  • A Novel Approach to Ring Resonator Theory Involving Even and Odd Mode Analysis

    Page(s): 856 - 862
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (365 KB) |  | HTML iconHTML  

    This paper presents a novel theoretical approach to the analysis of a ring resonator consisting of an edge-fed circular microstrip of arbitrary width on a substrate over a ground plane; the analysis takes into account the existing coupling between the two halves of the ring. The proposed theory, based on the ordinary quasi-transverse electromagnetic approach, makes use of multiconductor modal analysis tools where azymuthally coupled even and odd modes play a key role. Results concerning ring voltages and currents, ring input impedance, and ring resonance frequencies are developed. Novel results are compared with those obtained by using the standard approach valid for narrow strip. Radiation effects have been neglected. View full abstract»

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  • An Error Analysis of the Scattering Matrix Renormalization Transform

    Page(s): 863 - 868
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1614 KB) |  | HTML iconHTML  

    By characterizing the condition number as an indicator of accuracy, an error analysis is performed to determine how different auxiliary terminations affect the accuracy of the scattering matrix renormalization transform. Such an error analysis plays an essential role in enhancing the accuracy and widening the applicability of the port renormalization method for measuring multiport devices with a two-port vector network analyzer. View full abstract»

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  • A Stable Bayesian Vector Network Analyzer Calibration Algorithm

    Page(s): 869 - 880
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1441 KB) |  | HTML iconHTML  

    A new overdetermined vector network analyzer (VNA) calibration algorithm is presented. The new algorithm shows significant advantages in the measurement of very high-impedance devices such as carbon nanotube transistors and can be applied to all types of VNA calibration. It was found that, for high-impedance devices, the new algorithm yields up to four times more accurate results. The focus of this study is on the accuracy and robustness of the algorithm. A statistical error model of calibration, which includes errors in the calibration standards and errors in the VNA, is converted into a formula for calibration by Bayes' theorem. The numerical implementation of this formula makes use of nonlinear optimization techniques and Monte Carlo integration. The resulting new algorithm is compared against various other algorithms. Benchmarking shows that the presented calibration algorithm is robust and more accurate than all other tested algorithms in all tested calibration scenarios. View full abstract»

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  • Pulsed Active Load–Pull Measurements for the Design of High-Efficiency Class-B RF Power Amplifiers With GaN HEMTs

    Page(s): 881 - 889
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2194 KB) |  | HTML iconHTML  

    A novel pulsed class-B load-pull measurement system is developed to characterize GaN HEMTs targeting the design of high-efficiency class-B or class-C power amplifiers operating under a pulsed-bias and pulsed-RF (pulsed-IV/RF) condition. Based on a large-signal network analyzer, the test system uses an active load-pull method to provide stable open-loop pulsed-RF loads into the drain at omega0 and 2omega0 while bypassing slow-memory effects. The load-pull measurement data obtained from AlGaN/GaN HEMTs under the class-B operation reveal that there exist optimal loads for pulsed-IV/RF condition, which differ from the ones found for a dc-IV and continuous wave condition. This is due to the avoidance of slow-memory effects in the pulsed-IV/RF load-pull measurements, which are known to degrade the device RF performance: a 2-dB increase in output power is obtained for a GaN HEMT on sapphire. The optimized pulsed-RF active load for a GaN HEMT on SiC demonstrates a power-added efficiency of 82% with 17.8-dBm output power under quasi class-B pulsed operation at 2 GHz. View full abstract»

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  • Post-Compensation of Ultra-Wideband Antenna Dispersion Using Microwave Photonic Phase Filters and Its Applications to UWB Systems

    Page(s): 890 - 898
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (453 KB) |  | HTML iconHTML  

    We demonstrate experimental post-compensation of ultra-wideband (UWB) antenna dispersion at a receiver front-end by using programmable microwave photonic phase filtering. After the received RF signal is modulated onto an optical carrier, we utilize a hyperfine resolution optical pulse shaper to apply the conjugate of its spectral phase in the optical domain. After optical-to-electronic conversion, this yields an electrical waveform, which is compressed to bandwidth-limited duration. Further we use this technique in two schemes: a radar configuration in which we resolve two close echoes from different paths, which initially interfere and mask each other due to the dispersed response of the antenna link, and a spread-time UWB transmission configuration in which we retrieve and compress a distorted signal received in line-of-sight. To our knowledge, this is the first experimental demonstration of dispersion post-compensation of UWB RF waveforms to approach the ultimate bandwidth-limited resolution, as well as identification of such signals by matched filtering and compression. Our technique is programmable and offers potential to enhance performance in UWB radar and communications. View full abstract»

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  • Influence of Use Conditions and Mobile Phone Categories on the Distribution of Specific Absorption Rate in Different Anatomical Parts in the Brain

    Page(s): 899 - 904
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (529 KB) |  | HTML iconHTML  

    SAR distributions in different anatomical parts of the brain were estimated for different use conditions and phone categories for the purpose of exposure assessment in epidemiological studies on RF exposure and brain cancer risk. The results suggested a variability of the exposure of the different parts depending on use conditions and mobile phone categories and highlighted the importance of evaluating the risk by connecting the tumor location to phone categories and use conditions. It was observed that the RF exposure of structures, particularly for those at the back of the brain, is sensitive to the phone shape and the antenna position relative to the head. The temporal lobe was generally the part with the highest exposure to RF, except for flip-type phones with the antenna on top extended. Occipital lobe and cerebellum were generally the second-highest exposed parts; exposure of parietal and frontal lobes were generally low, except for flip-type phones with the antenna in the center. It was observed that the exposure of the cerebellum cannot be neglected, whereas it was generally assumed to be low in previous epidemiological studies. View full abstract»

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  • IEEE Transactions on Microwave Theory and Techniques information for authors

    Page(s): 905
    Save to Project icon | Request Permissions | PDF file iconPDF (23 KB)  
    Freely Available from IEEE
  • Special issue on THz technology: bridging the microwave-to-photonics gap

    Page(s): 906
    Save to Project icon | Request Permissions | PDF file iconPDF (163 KB)  
    Freely Available from IEEE
  • IEEE Foundation [advertisement]

    Page(s): 907
    Save to Project icon | Request Permissions | PDF file iconPDF (320 KB)  
    Freely Available from IEEE

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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Dominique.Schreurs@ieee.org

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