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Microwave Theory and Techniques, IEEE Transactions on

Issue 8 • Date Aug. 2007

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Displaying Results 1 - 25 of 33
  • Table of contents

    Publication Year: 2007 , Page(s): C1 - C4
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  • IEEE Transactions on Microwave Theory and Techniques publication information

    Publication Year: 2007 , Page(s): C2
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  • Exact Analysis of the Wire-Bonded Multiconductor Transmission Line

    Publication Year: 2007 , Page(s): 1585 - 1592
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1095 KB) |  | HTML iconHTML  

    In this paper, the exact model of a multiconductor transmission line with bonding wires is presented. The model is based on the multiport admittance matrix, and is valid for any number of conductors in the structure. The model shows how to compute the two-port admittance matrix of the wire-bonded structure with direct application to the wire-bonded interdigital capacitor. The model has been validated by means of method-of-moments-based numerical simulation and by experimental work. View full abstract»

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  • A 1-V Wideband Low-Power CMOS Active Differential Power Splitter for Wireless Communication

    Publication Year: 2007 , Page(s): 1593 - 1600
    Cited by:  Papers (4)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (658 KB) |  | HTML iconHTML  

    A 1-V wideband CMOS phase and power splitter (PPS) with an RLC network load and frequency compensation capacitor is proposed. Adopting the RLC network load and the frequency compensation capacitor, the gain and phase imbalances of the output can be improved and the wideband response can be achieved, respectively. Moreover, this architecture can not only offer high transfer power gain, but also adopts the tuning current source to overcome the power imbalance caused by process variation. An example with a differential phase condition (180deg) has been designed and fabricated. Based on our measured results, in the frequency range from 3.5 to 6 GHz, the phase error is less than 7deg and the power imbalance is less than 1.4 dB. For wireless local area network 802.11a applications in the frequency range from 5.15 to 5.35 GHz, the phase error is less than 0.6deg, and the power imbalances are less than 0.27 dB, respectively. In addition, the transfer power gain is 9.66 dB under the power consumption of 15 mW and 1-V supply voltage. This architecture is different from the passive PPS circuit, and it has the advantages of no conversion loss and a small chip area with 0.8 mm times 0.7 mm. Compared with the conventional active PPSs, such as using the GaAs and BiCMOS process, this architecture implemented by the TSMC 0.18-mum CMOS process is competitive in cost and possesses the characteristics of low voltage and low power, and it is more easily integrated and suitable for system-on-a-chip applications. View full abstract»

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  • Analysis and Design of Bandpass Single-Pole–Double-Throw FET Filter-Integrated Switches

    Publication Year: 2007 , Page(s): 1601 - 1610
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1553 KB) |  | HTML iconHTML  

    This paper proposes a method to integrate a single-pole - double-throw (SPDT) switch and a quarter-wavelength bandpass filter. A 1-GHz SPDT hybrid switch and a 60-GHz pseudomorphic HEMT monolithic-microwave integrated-circuit SPDT switch with 30% fractional bandwidth are demonstrated. The 1-GHz SPDT switch achieves 1.5-dB insertion loss and 20-dB isolation at center frequency. For the 60-GHz SPDT switch, the measured insertion loss is lower than 2.5 dB and the isolation is higher than 27 dB. The low insertion loss and high isolation show that no performance is degraded when integrating the filter function. The analysis of the power performance is also described. Using the device dc-IV curves, the power compression point can be predicted. View full abstract»

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  • Printed and Integrated CMOS Positive/Negative Refractive-Index Phase Shifters Using Tunable Active Inductors

    Publication Year: 2007 , Page(s): 1611 - 1623
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1409 KB) |  | HTML iconHTML  

    This paper presents a printed and an integrated bi-directional tunable positive/negative refractive-index phase shifter utilizing CMOS tunable active inductors (TAIs). The printed phase shifter is comprised of a microstrip transmission line (TL), loaded with series varactors and a shunt monolithic microwave integrated circuit (MMIC) synthesizing the TAI. Using the TAI extends the phase tuning range and results in a low return loss across the entire tuning range. The integrated circuit (IC) phase shifter replaces the TLs with suitable lumped L-C sections. This enables integrating the entire phase shifter on a single MMIC, resulting in a compact implementation. The TAI used for both phase shifters is based on a modified gyrator-C architecture, employing a variable resistance to independently control the inductance and quality factor. The TAI is fabricated in the 0.13-mum CMOS process and operates from a 1.5-V supply. The TAI chip is used to implement the TL phase shifter, which achieves a phase of -40deg to +34deg at 2.5 GHz with less than -19-dB return loss from a single stage occupying 10.8 mm times 10.4 mm. The IC phase shifter is fabricated in the same process and achieves a phase from -35deg to +59deg at 2.6 GHz with less than -19-dB return loss from a single stage occupying 550 mum times 1300 mum. View full abstract»

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  • A 20-Gb/s 1 : 2 Demultiplexer With Capacitive-Splitting Current-Mode-Logic Latches

    Publication Year: 2007 , Page(s): 1624 - 1632
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1789 KB) |  | HTML iconHTML  

    This paper presents a high-speed 1:2 demultiplexer (DEMUX) implemented in a 0.18-mum CMOS process. By employing a capacitive-splitting architecture for the current-mode-logic latches, a significant speed improvement is achieved in the proposed DEMUX. Provided a 223 - 1 pseudorandom bit sequence from the pattern generator, the fabricated circuit operates at an input data rate up to 20 Gb/s. The fully integrated DEMUX consumes a dc power of 150 mW from a 2-V supply voltage. View full abstract»

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  • Multitone Fast Frequency-Hopping Synthesizer for UWB Radio

    Publication Year: 2007 , Page(s): 1633 - 1641
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1291 KB) |  | HTML iconHTML  

    A fast frequency-hopping six-band local oscillator signal generator is described in this paper. Targeted for a Wi-Media ultra-wideband radio transceiver, it offers operation in mandatory band group 1 and in extensional band group 3. The circuit entity consists of three parallel phase-locked loops (PLLs), each including two voltage-controlled oscillators, one per band group, and a signal multiplexer for fast frequency selection. A broadband poly-phase RC filter is used for in-phase/quadrature generation. Furthermore, the synthesizer generates the clock signal for analog-to-digital converters by mixing the signals from the first and third PLL. The circuit was fabricated in a 0.13- mum CMOS process and it consumes 32 mA from a 1.2-V supply. It achieves 2-ns frequency settling time with a 3-MHz hopping rate. View full abstract»

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  • A New X-Band Low Phase-Noise Multiple-Device Oscillator Based on the Extended-Resonance Technique

    Publication Year: 2007 , Page(s): 1642 - 1648
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1166 KB) |  | HTML iconHTML  

    A novel multiple-device oscillator based on the extended-resonance technique is proposed. This oscillator achieves low phase noise through optimizing the circuit's group delay. Based on this technique, an X-band four-device SiGe HBT oscillator has been designed, fabricated, and tested. The measured phase noise is - 119 dBc at 100-kHz offset frequency. To the authors' best knowledge, this oscillator shows the lowest phase-noise performance among other reported X-band microwave planar hybrid free-running oscillators. View full abstract»

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  • Design and Analysis of a Millimeter-Wave Direct Injection-Locked Frequency Divider With Large Frequency Locking Range

    Publication Year: 2007 , Page(s): 1649 - 1658
    Cited by:  Papers (36)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1073 KB) |  | HTML iconHTML  

    In this paper, direct injection-locked frequency dividers (ILFDs), which operate in the millimeter-wave (MMW) band, are analyzed. An analytically equivalent model of the direct ILFDs is developed, and important design guidelines for a large frequency locking range are obtained from it. These guidelines are: 1) maximize the quality factor of the passive load; 2) maintain low output amplitude; and 3) increase the dc overdrive voltage of the input device. A direct ILFD without varactors is designed and fabricated using a 0.13-mum bulk CMOS process to verify the developed model and design guidelines. A pMOS current source is used to restrict the output amplitude and to increase the dc overdrive voltage of the input device to achieve a large frequency locking range. The size of the input device is only 3.6 mum/0.12 mum and the measured frequency locking range is 13.6% at 70 GHz with a power consumption of 4.4 mW from a supply voltage of 1 V. In short, the proposed divider has the potential to be integrated into an MMW phase-locked loop system. View full abstract»

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  • W-Band Waveguide Impedance Tuner Utilizing Dielectric-Based Backshorts

    Publication Year: 2007 , Page(s): 1659 - 1665
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (841 KB) |  | HTML iconHTML  

    We present the design, simulations, fabrication, and measurements of a W-band waveguide impedance tuner. The design consists of a WR-10 waveguide with two E-plane arms for tunable dielectric-based backshorts. The impedance tuner is fabricated using a simple split-block technique and is easily scalable to submillimeter wavelengths. Our design shows an excellent input impedance range, tuning accuracy, repeatability, and a high attainable maximum reflection coefficient over the frequency band of 75-110 GHz. Our tuner applies dielectric-based backshorts, which provide a tuning accuracy better than that of other waveguide backshorts. View full abstract»

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  • Variable Antenna Load for Transmitter Efficiency Improvement

    Publication Year: 2007 , Page(s): 1666 - 1672
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (759 KB) |  | HTML iconHTML  

    A wireless radio transmitter with an integrated variable-impedance antenna is demonstrated. The transmit signal is connected via a switch to the antenna at one of several feed points that correspond to different load impedances that are optimal for the power amplifier at different transmit power levels. It is shown that this can be used to improve the efficiency of the transmission at low and medium transmit powers. The variable antenna load is demonstrated with a planar inverted-F antenna, but the method can be applied to any antenna with suitable impedances. View full abstract»

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  • Rigorous Analysis of a Metallic Circular Post in a Rectangular Waveguide With Step Discontinuity of Sidewalls

    Publication Year: 2007 , Page(s): 1673 - 1684
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (527 KB) |  | HTML iconHTML  

    The scattering of guided waves by a conductive post placed inside a rectangular waveguide with a step discontinuity on its sidewalls is analyzed through an integral-equation formulation. The interaction between post and discontinuity is examined with use of the Green's function. Numerical computations are carried out based on the mode-matching technique, providing a stable and accurate solution. An equivalent-circuit model is developed from the electromagnetic analysis and the computed scattering S-parameters. The developed solution accuracy is validated with simulation software. View full abstract»

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  • Reactance of Posts in Circular Waveguide

    Publication Year: 2007 , Page(s): 1685 - 1688
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (423 KB) |  | HTML iconHTML  

    Experimental and numerical simulation results are presented for the reactance of centered variable-height single and double posts in a circular waveguide. The reactance is a function of the waveguide and post dimensions and frequency, and the results presented are useful in the design of a variety of circular waveguide devices involving these elements. View full abstract»

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  • Fourier Decomposition Analysis of Anisotropic Inhomogeneous Dielectric Waveguide Structures

    Publication Year: 2007 , Page(s): 1689 - 1696
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (685 KB) |  | HTML iconHTML  

    In this paper, we extend the Fourier decomposition method to compute both propagation constants and the corresponding electromagnetic field distributions of guided waves in millimeter-wave and integrated optical structures. Our approach is based on field Fourier expansions of a pair of wave equations, which have been derived to handle inhomogeneous mediums with diagonalized permittivity and permeability tensors. The tensors are represented either by a grid of homogeneous rectangles or by distribution functions defined over rectangular domains. Using the Fourier expansion, partial differential equations are converted to a matrix eigenvalue problem that correctly models this class of dielectric structures. Finally, numerical results are presented for various channel waveguides and are compared with those of other literature to validate the formulation. View full abstract»

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  • Analysis of a TE22,6 118-GHz Quasi-Optical Mode Converter

    Publication Year: 2007 , Page(s): 1697 - 1703
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1977 KB) |  | HTML iconHTML  

    A quasi-optical mode converter for the European TE22,6 118-GHz gyrotron has been continuously improved for long pulse operation. Measurements at the last generation show a double peak structure at the output window plane, but simulations have not been able to explain this behavior in the past. The overall output system was analyzed carefully. Besides measurements, the first full 3D electromagnetic analysis of a complete quasi-optical mode converter was performed. This gives the indication of the double-peak structure at the output window plane. An enhancement of the system for a single-peak Gaussian-like output beam will be presented. View full abstract»

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  • Mixed-Mode Chain Scattering Parameters: Theory and Verification

    Publication Year: 2007 , Page(s): 1704 - 1708
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB) |  | HTML iconHTML  

    Chain scattering parameters or T-parameters are a useful tool for calculating cascaded two-ports. With the increasing importance of mixed-mode S-parameters, a need for converting the T-parameters from their unbalanced form into a balanced form emerges for suiting both common and differential mode waves, as well as the mode conversion. This paper presents the derivation of the equations for transformations between mixed-mode S- and T-parameters for a mixed-mode two-port. Although derived in a way very similar to monomode T-parameters, no simplifications were necessary. Measurement results exemplify the quality of the T-parameter transformation under real-life conditions. View full abstract»

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  • A General Multigrid-Subgridding Formulation for the Transmission Line Matrix Method

    Publication Year: 2007 , Page(s): 1709 - 1716
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (862 KB) |  | HTML iconHTML  

    This paper introduces a general multigrid-subgridding formulation aimed at improving the efficiency of the transmission line matrix method. The rigorous algebraic procedure, based on Hilbert space formulation, leads to the definition of a general boundary scattering matrix, which interfaces 3-D regions of uniform computational mesh with different spatial resolution, thus allowing the modeling of objects of very disparate geometrical or electrical scale, e.g., such occurring in nanodevices. Computational acceleration and accuracy are measured by comparing the run time of simulations performed with subgridding to the run time of simulations without any subgridding. View full abstract»

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  • Resonance Absorption in Nonsymmetrical Lossy Dielectric Inserts in Rectangular Waveguides

    Publication Year: 2007 , Page(s): 1717 - 1722
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    Features of resonance power absorption in a lossy dielectric resonator shaped as a rectangular trapezium in a rectangular waveguide are studied. It is found that such a resonator can provide strong absorption (or reflection) of the TE10-mode input from the straight (or inclined) interface port. The maximum absorption is observed when the sum of the coupling coefficients equals unity. Simple formulas relating the scattering and absorption coefficients with the coupling coefficients at the resonance frequency are presented. The physical mechanism of resonance absorption is discussed. View full abstract»

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  • An Efficient Application of the Discrete Complex Image Method for Quasi-3-D Microwave Circuits in Layered Media

    Publication Year: 2007 , Page(s): 1723 - 1729
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (574 KB) |  | HTML iconHTML  

    An efficient means of evaluating reactions arising from the mixed-potential integral equation for layered media for quasi-3D microwave circuits is presented. Analytical formulations for the z-integration in the spectral domain are derived, thus avoiding expensive 2D evaluation and interpolation of the layered Green's function. In this paper, closed-form formulations for the resultant Sommerfeld integrals are evaluated via the robust two-step discrete complex image method. The overall computational time can consequently be greatly reduced when analyzing quasi-3D circuits in layered media using the proposed method. View full abstract»

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  • New Series Expansions for the 3-D Green's Function of Multilayered Media With 1-D Periodicity Based on Perfectly Matched Layers

    Publication Year: 2007 , Page(s): 1730 - 1738
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (423 KB) |  | HTML iconHTML  

    A new formalism based on perfectly matched layers (PMLs) is presented to derive new series expansions for the Green's function of an infinite set of point sources with a 1-D periodicity embedded in a layered medium. Several PML-based series expansions, both in the spatial and spectral domains, combined with suitable convergence acceleration techniques such as the Shanks transform and Ewald transform, are proposed and their efficiency is evaluated. For each pair of excitation and observation locations, an optimal series expansion in terms of accuracy and CPU time is proposed, resulting in a significant speed-up compared to existing approaches. View full abstract»

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  • Interpolated Coarse Models for Microwave Design Optimization With Space Mapping

    Publication Year: 2007 , Page(s): 1739 - 1746
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB) |  | HTML iconHTML  

    The efficiency of space-mapping optimization depends on the quality of the underlying coarse model, which should be sufficiently close to the fine model and cheap to evaluate. In practice, available coarse models are often cheap, but inaccurate (e.g., a circuit equivalent of the microwave structure) or accurate, but too expensive (e.g., a coarse-mesh model). In either case, the space-mapping optimization process exhibits substantial computational overhead due to the excessive fine model evaluations necessary to find a good solution if the coarse model is inaccurate, or due to the cost of the parameter extraction and surrogate optimization sub-problems if the coarse model is too expensive. In this paper, we use an interpolation technique, which allows us to create coarse models that are both accurate and cheap. This overcomes the accuracy/cost dilemma described above, permitting significant reduction of the space-mapping optimization time. Examples verify the performance of our approach. View full abstract»

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  • Compact Planar Quasi-Elliptic Function Filter With Inline Stepped-Impedance Resonators

    Publication Year: 2007 , Page(s): 1747 - 1755
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1080 KB) |  | HTML iconHTML  

    Compact microstrip bandpass filters of orders N = 4,6, and 8 with quasi-elliptic function responses are synthesized with inline stepped-impedance resonators. The filters have enhanced transition responses since two transmission zeros are generated on both sides of the passband. Existence of these two zeros is investigated by formulating the Y-matrix of the equivalent circuit for the filter and taking adjacent and nonadjacent coupling into account. Some matrix elements Yj,j+2 representing coupling between two nonadjacent resonators are shown to have the opposite signs in both the lower and upper sides of the center frequency. This property leads to creation of the two transmission zeros on both sides of the passband. It is demonstrated that one more zero can be created in the rejection band by the tapped-line input/output scheme. Experimental circuits on substrates with epsivr = 2.2 and 10.2 are measured to validate the theory and design. View full abstract»

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  • Balanced Coupled-Resonator Bandpass Filters Using Multisection Resonators for Common-Mode Suppression and Stopband Extension

    Publication Year: 2007 , Page(s): 1756 - 1763
    Cited by:  Papers (34)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1568 KB) |  | HTML iconHTML  

    Novel fourth-order balanced coupled-resonator bandpass filters are proposed using suitably designed half-wavelength (lambda/2) multisection resonators for common-mode suppression. By properly designing the input/output (I/O) resonators associated with the filter composed of four bi-section resonators, a balanced filter with good common-mode suppression is realized, but its rejection bandwidth is rather limited. To widen the rejection bandwidth, the I/O bi-section resonators are replaced by the tri-section ones so that a balanced filter with good common-mode suppression and wide rejection bandwidth may be realized by suitably arranging the composed bi-/tri-section resonators. Specifically, a stopband-extended balanced filter with good common-mode suppression (>50 dB) within the differential-mode passband is implemented and its stopbands are also extended up to 5f0 d with a rejection level of 30 dB, where f0 d is the center frequency in differential-mode operation. View full abstract»

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  • Dual-Mode Microstrip Open-Loop Resonators and Filters

    Publication Year: 2007 , Page(s): 1764 - 1770
    Cited by:  Papers (89)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1168 KB) |  | HTML iconHTML  

    A miniature dual-mode microstrip open-loop resonator is proposed. Distinct characteristics of this new type of dual-mode resonator are investigated using full-wave electromagnetic simulations. It is shown that the two operating modes, i.e., the even and odd modes, within a single dual-mode resonator of this type do not couple. It is also found that there is a finite-frequency transmission zero inherently associated with the even mode. Two two-pole filters using this type of dual-mode resonator are demonstrated with opposite asymmetric responses, which result from different locations of the transmission zero. Higher order filters of this type are also investigated. Both simulated and measured results are presented. 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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Dominique Schreurs
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Editor-in-Chief
Jenshan Lin
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