Scheduled System Maintenance on May 29th, 2015:
IEEE Xplore will be upgraded between 11:00 AM and 10:00 PM EDT. During this time there may be intermittent impact on performance. We apologize for any inconvenience.
By Topic

Microwave Theory and Techniques, IEEE Transactions on

Issue 10 • Date Oct. 1994

Filter Results

Displaying Results 1 - 25 of 28
  • Comments on "Analysis of the effects of a resistively coated upper dielectric layer on the propagation characteristics of hybrid modes in a waveguide-shielded microstrip using the method of lines"

    Publication Year: 1994
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (115 KB)  

    In the original paper [see ibid., vol. 41, p 1393-99,1993], a long derivation is given to consider a thin resistive layer of a structure in the analysis procedure with the MoL. But it is claimed that all that is needed is a one-line derivation.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comments on "The influence of finite conductor thickness and conductivity on fundamental and higher-order modes in miniature hybrid MIC's (MHMIC's) and MMIC's" [with reply]

    Publication Year: 1994 , Page(s): 2013 - 2016
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (233 KB)  

    For original paper see K. Wu, R. Vahldieck, J. Fikart and K. Minkus, ibid., vol.41, pp.421-430 (1993). This comment has been written because the authors are of the view that some statements in the above paper cannot remain uncontradicted, and to help researchers using the method of lines in case of numerical difficulties. A reply by R. Vahldieck and K. Wu is included.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dielectric properties of single crystals of Al2O3 , LaAlO3, NdGaO3, SrTiO3, and MgO at cryogenic temperatures

    Publication Year: 1994 , Page(s): 1886 - 1890
    Cited by:  Papers (44)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    A dielectric resonator technique has been used for measurements of the permittivity and dielectric loss tangent of single-crystal dielectric substrates in the temperature range 20-300 K at microwave frequencies. Application of superconducting films made it possible to determine dielectric loss tangents of about 5×10-7 at 20 K. Two permittivity tensor components for uniaxially anisotropic samples were measured. Generally, single-crystal samples made of the same material by different manufacturers or by different processes save significantly different losses, although they have essentially the same permittivities. The permittivity of one crystalline ferroelectric substrate, SrTiO3, strongly depends on temperature. This temperature dependence can affect the performance of ferroelectric thin-film microwave devices, such as electronically tunable phase shifters, mixers, delay lines and filters View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An application of FD-TD method for studying the effects of packages on the performance of microwave and high speed digital circuits

    Publication Year: 1994 , Page(s): 2007 - 2009
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB)  

    The finite-difference time-domain (FD-TD) method is combined with an appropriate time-frequency discrete conversion technique to analyze packaging and time domain transition effects of microwave and high speed digital circuits. The output response of a given input pulse is obtained by linear convolution of the input signal with time domain system function, which is obtained through FD-TD simulation of the whole packaging system including coaxial to microstrip line transitions. As an example, a shielded microstrip line which is connected with coaxial lines, is analyzed and measured. The comparison between experimental and numerical results shows very a good agreement View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Frequency domain analysis of RF and microwave circuits using SPICE

    Publication Year: 1994 , Page(s): 1904 - 1909
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    The SPICE circuit analysis program has limited math capability and, in general, cannot be used for RF and microwave simulation because complex arithmetic is required to compute S-parameters from node voltages. This paper presents two models of a directional coupler that can be used to obtain node voltages proportional to incident, reflected, and transmitted signals. These models are based on a previously developed multiple coupled transmission line (MTL) SPICE model. From SPICE computed node voltages, S-parameters are computed using the math capability of the PSPICE post processor, PROBE, as an example for a low-pass filter consisting of transmission line sections. The results of this example are compared with another high-frequency circuit analysis program, TOUCHSTONE. The difference between the results of these two programs in magnitude was less than 0.005 and in phase was a few tenths of a degree. By using these couplers to simulate a network analyzer, RF and microwave analysis can be made with SPICE, which can be a cost-effective and readily available computational tool for educators and practicing engineers View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An efficient self-oscillating mixer for communications

    Publication Year: 1994 , Page(s): 1858 - 1862
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (396 KB)  

    The optical control of the distributed electronics in phased array antennas requires specialized circuits which are compatible with the T/R level data mixing architecture. This paper presents a novel circuit, a push-pull self-oscillating mixer, that can provide the following important advantages: 1) very stable free running oscillation and low FM noise without using a frequency stabilizing dielectric resonator; 2) large subharmonic injection locking range; 3) high frequency conversion efficiency; and 4) low noise figure for the self-oscillating mixer. This proposed circuit efficiently oscillates and mixes with a low prime power consumption. A circuit topology based on this concept was analyzed and designed at 12 GHz using a MESFET pair. Efficient subharmonic injection locking was demonstrated by selecting the optimum operating point corresponding to efficient mixing. The measured down-conversion gain was as high as 13 dB with a double sideband noise figure of 8 dB. This topology can be directly applied for MMIC applications View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spike leakage of thin Si PIN limiters

    Publication Year: 1994 , Page(s): 1879 - 1885
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (616 KB)  

    Thin PIN diode limiters (10 μm or less) are used to protect sensitive microwave components from fast-risetime microwave pulses having energies exceeding 1 to 10 μJ. This paper analyzes and experimentally confirms the performance of these PIN limiters. It is shown that spike leakage is a transit-time effect that is controlled by the mobility of the carriers. A p-type background I-region should yield less spike leakage energy for a given thickness. It is proposed that the hysteresis effect observed when limiters are operated under cw conditions is due to space charge effects and stored charges remaining after the reverse-biased half cycle. Detailed agreement between the measured and calculated device voltage waveforms requires accurate modeling of the circuit parasitics because of the high rate-of-change currents arising from avalanching View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the use of differential equations of nonentire order to generate entire domain basis functions with edge singularity

    Publication Year: 1994 , Page(s): 1966 - 1972
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (556 KB)  

    Entire domain analytical basis functions with edge singularity are a very useful tool for analysing planar transmission lines and planar rectangular or circular circuits in a moment method solution. Analytical basis functions are limited to separable geometry. In this paper we introduce new entire domain basis functions including edge singularity at the edges of a domain with arbitrary shape. These basis functions are derived from a differential equation of nonentire order which includes a fractional derivative. The one dimensional case is considered first. In the two dimensional case the basis functions are constructed numerically using the boundary element method and the Galerkin method. The basis functions are applied in a moment method solution to analyse a shielded microstrip. The current and the electric field are calculated and compared with the results obtained by analytical basis functions View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • AlGaAs/GaAs HBT linearity characteristics

    Publication Year: 1994 , Page(s): 1845 - 1850
    Cited by:  Papers (39)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (592 KB)  

    Communication systems require linear power amplifiers with high efficiency and very low intermodulation distortion. AlGaAs/GaAs heterojunction bipolar transistors (HBT's) were found to have very low intermodulation distortion in power operation. Two-tone tests were carried out on both common-emitter (CE) and common-base (CB) power HBT's. At 7 GHz, the CE HBT showed -20 dBc IM3 (third-order intermodulation ratio) and 12% power added efficiency (PAE) per tone at the 1 dB gain compression point; IM3 dropped to -30 dBc at 1.5 dB output power backoff. The CE HBT has lower intermodulation distortion than CB HBT. Load pull data were collected to aid the understanding of the intermodulation. Parameters of the Gummel-Poon model (as used in SPICE) were derived for HBT's based on dc data and small-signal S parameters at various bias points. The accuracy and validity of the model were confirmed by comparison to experimental two-tone results. SPICE predicts that the emitter and base resistances linearize the HBT and reduce the third-order intermodulation distortion. The excellent third-order intermodulation performance of the CE HBT makes it a very attractive choice for linear power amplifiers View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of MESFET injection-locked oscillators in fundamental mode of operation

    Publication Year: 1994 , Page(s): 1851 - 1857
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB)  

    In this paper, nonlinear analyses of MESFET oscillator in free-running and injection-locked states are studied based on the Volterra series method and stability analysis. The approach shown is capable of quantitatively analyzing the injection locking performance of oscillator using three-terminal devices in the fundamental mode of operation. Both the transmission-type and reflection-type injection locked oscillators (ILO) are simulated and experimentally verified View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Using linear and nonlinear predictors to improve the computational efficiency of the FD-TD algorithm

    Publication Year: 1994 , Page(s): 1992 - 1997
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    It is well known that the Finite-Difference Time-Domain (FD-TD) method requires long computation times for solving electromagnetic problems, especially for high-Q structures. The reason for this is because the algorithm is based on the leap-frog formula. In this paper, both linear and nonlinear predictors, which are widely used in signal processing, are introduced to reduce the computation time of the FD-TD algorithm. A short segment of an FD-TD record is used to train the predictor. As long as the predictor is set up properly, an accurate future realization can be obtained. We demonstrate, by means of numerical results, that the efficiency of the FD-TD method can be improved by up to 90%. With this result, the FD-TD algorithm becomes a much more attractive technique for solving electromagnetic problems View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental proof-of-principle results on a mode-selective input coupler for gyrotron applications

    Publication Year: 1994 , Page(s): 1910 - 1917
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (784 KB)  

    Proof-of-principle results for a mode selective input coupler are presented. Transmission and reflection measurements for the TE02 cylindrical waveguide mode are given along with the output mode pattern. The results show good agreement for the cutoff frequency, mode pattern general behavior and variation with frequency for signals above cutoff. A maximum passband of 1.2 GHz (~7%) has been achieved. Comparisons with theory for overall frequency response (from 15 to 18 GHz) and mode pattern characteristics (at 17.5 GHz) are also presented. The design and concept are promising for harmonic gyrotron-traveling-wave-tube amplifier and phase-locked gyrotron oscillator applications View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Leakage characteristics of groove guide having a conductor strip

    Publication Year: 1994 , Page(s): 1925 - 1931
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (544 KB)  

    A full-wave characterization of the groove guide having a conductor strip is made based on the mode-matching procedure. All of the constituents of the structure, including a coupling strip, grooves and a radiating open end, are treated in a concise and rigorous way by using the generalized scattering matrix technique. Numerical results show that a set of channel guide leaky modes is also present in this structure in addition to the groove guide leaky mode. The complex propagation behaviors of both the groove guide leaky mode and the channel guide leaky mode are illustrated for various waveguide geometric parameters, and some conclusions regarding the design of leaky wave antennas using this structure are drawn View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A 94 GHz planar monopulse tracking receiver

    Publication Year: 1994 , Page(s): 1863 - 1871
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB)  

    This paper describes the design, fabrication and measurements of a 94 GHz integrated monopulse receiver with IF beam control. The receiver is integrated on a single chip, and is based on a 23 GHz local oscillator driving four separate phase-coherent 94 GHz subharmonic mixers. The resulting IF signals are takeoff-chip to a IF monopulse processor, which produces sum and difference monopulse patterns for the elevation and azimuth coordinates. Voltage-controlled phase-shifters in each of the IF channels allow the monopulse patterns to be electronically steered. All of the receiver circuits are realized using uniplanar coplanar-waveguide (CPW), slot lines and coplanar striplines (CPS). These features result in a compact, low-cost system suitable for tracking systems operating in poor visibility conditions, as well as in collision avoidance receivers for automotive applications. To our knowledge, this work represents the first demonstration of a fully integrated millimeter-wave subsystem to date View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Some important properties of waveguide junction generalized scattering matrices in the context of the mode matching technique

    Publication Year: 1994 , Page(s): 1896 - 1903
    Cited by:  Papers (38)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (648 KB)  

    Some important properties for the generalized scattering matrix [S] of waveguide step discontinuities, in the context of the mode matching technique, are derived by considering the conservation of the complex power and self reaction across the discontinuities. Apart from their theoretical significance, these properties are useful for the numerical verification of the mode matching technique when designing waveguide circuits. The properties are shown to apply in the general case of junctions between lossless inhomogeneously filled waveguides, and they are proven to remain valid irrespective of the number of modes retained in the field expansions. During the process of deriving these properties, the mode matching technique for a waveguide step discontinuity is revisited and some subtle theoretical issues are resolved. In this framework, the selection of the appropriate testing modes for enforcing the field continuity conditions across the discontinuity is rigorously justified. In addition, two distinct mode matching formulations corresponding to the two possible orthogonality relations among the eigenmodes of lossless waveguides are proven to be equivalent. Finally, it is shown that the correct application of the held boundary conditions across the step discontinuity implies requirements on the number of modes used to represent the fields, in each waveguide, which are compatible with the relative convergence criterion View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Study of microstrip step discontinuities on bianisotropic substrates using the method of lines and transverse resonance technique

    Publication Year: 1994 , Page(s): 1945 - 1950
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    A hybrid approach, combining the method of lines (MoL) and transverse resonance technique (TRT), is presented for the analysis of microstrip step discontinuities that are printed on uniaxial or biaxial bi-anisotropic substrates. The method of lines, formulated in terms of Kronecker products, is used to determine the characteristic equation for the resonant length. The transverse resonance technique is applied to obtain the S-parameters of the junction by casting the discontinuity problem as a microwave equivalent network. Good agreement is found between results of the MoL/TRT approach and those obtained by other methods. Effects of individual tensor elements of the substrate on the scattering parameters of the discontinuity are investigated at selected frequencies. The proposed MoL/TRT approach is found to converge very fast and does not require excessive computer memory, with all computations performed on a 486DX-50 MHz PC View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The dominant mode in a parallel-plate chirowaveguide

    Publication Year: 1994 , Page(s): 2009 - 2012
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB)  

    It has been reported that the lowest cutoff frequency of the modes in a parallel-plate chirowaveguide is not zero. In this paper, we show that a dominant mode of trivial cutoff frequency may be supported by such a chirowaveguide. The mode exhibits the characteristics of a TEM mode when the chirality of the medium vanishes or the operating frequency is very low. An analogous mode also exists in a bianisotropic chiral coaxial line, i.e., the structure formed by more than one conductor View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerically efficient spectral domain approach to the quasi-TEM analysis of supported coplanar waveguide structures

    Publication Year: 1994 , Page(s): 1958 - 1965
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    A numerically improved technique for the quasi-TEM analysis of supported coplanar waveguides is presented. The spectral domain method is combined with a special set of basis functions, to facilitate an accurate and efficient solution. The resulting integrals are evaluated using closed-form expressions instead of numerical integration scheme which leads to short CPU time. In this study, numerical results for the characteristic impedances of coplanar waveguides are presented. Comparisons are also made between the computed results and available ones. The charge density distributions on the center signal strip as well as on the ground plane are examined View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improved wire modelling in TLM

    Publication Year: 1994 , Page(s): 1978 - 1983
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (520 KB)  

    An important aspect in the application of transmission-line modelling (TLM) to microwave circuit and electromagnetic compatibility (EMC) simulation studies is the accurate modelling of wires and wire-like structures. This paper outlines the cause of errors arising from simplified descriptions often used when modelling wires by integrated solution methods in TLM. It proposes a simple solution which is validated against experimental results for a number of test configurations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Finite element computation of electromagnetic fields [hyperthermia treatment]

    Publication Year: 1994 , Page(s): 1984 - 1991
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    A three dimensional finite element solution scheme is developed for numerically computing electromagnetically induced power depositions. The solution method is applicable to those problems for which it can be reasonably assumed that the magnetic permeability is homogeneous. The method employs an incident field/scattered field approach where the incident field is precalculated and used as the forcing function for the computation of the scattered field. A physically logical condition is used for the numerical boundary conditions to overcome the fact that electromagnetic problems are generally unbounded (i.e., the boundary condition is applied at infinity) but numerical models must have a boundary condition applied to some finite location. At that numerical boundary, an outgoing spherical wave is simulated. Finally, an alternate to a direct solution scheme is described. This alternate method, a preconditioned conjugate gradient solver, provides both a storage and CPU time advantage over direct solution methods. For example, a one-thousand fold decrease in CPU time was achieved for simple test cases. Unlike most iterative methods, the preconditioned conjugate gradient technique used has the important property of guaranteed convergence. Solutions obtained from this finite element method are compared to analytic solutions demonstrating that the solution method is second-order accurate View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Finite-difference analysis of dielectric-loaded cavities using the simultaneous iteration of the power method with the Chebyshev acceleration technique

    Publication Year: 1994 , Page(s): 1998 - 2006
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (764 KB)  

    A numerical procedure using the finite-difference technique, simultaneous iteration based on the power method, and the Chebyshev-polynomial preconditioning is proposed to analyze dielectric-loaded cavities. The merit of this method is that no matrix inversions are invoked and the convergence rate of the power method is greatly accelerated by the preconditioning. The TE, TM, and hybrid modes in axisymmetrical cavities loaded with a rod or ring dielectric resonator are analyzed. For the hybrid modes, an Hr-Hz formulation is proposed. Accurate numerical results are obtained efficiently and no spurious solutions are found by the present method View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental analysis of millimeter wave coplanar waveguide slow wave structures on GaAs

    Publication Year: 1994 , Page(s): 1918 - 1924
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (672 KB)  

    Microwave coplanar waveguide slow wave structures suitable for use in traveling wave electrooptic modulators were experimentally investigated to 40 GHz. Velocity slowing is achieved by introducing periodic slots in the ground planes. Structures both on semiinsulating GaAs substrates and on epitaxial layers grown by molecular beam epitaxy on semiinsulating GaAs substrates were examined. In the measurements the thru-reflect-line calibration method was used and its limitations are discussed. The characteristic impedance, phase velocity and loss coefficient of these lines were extracted from measured S-parameters. Effects of various dimensions on these line properties are presented and discussed. Results indicate that significant phase velocity slowing without dispersion at least up to 40 GHz is possible with this approach. This is true both on semi-insulating GaAs substrates and specially designed epitaxial layers. A design approach to achieve a specified phase velocity and characteristic impedance is given View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power and spatial mode measurements of sideband generated, spatially filtered, submillimeter radiation

    Publication Year: 1994 , Page(s): 1891 - 1895
    Cited by:  Papers (12)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    The first coherent measurement of submillimeter-wave sideband generator (SBG) output power is reported here. This SBG utilizes a submillimeter laser, microwave synthesizer, and high frequency Schottky diode to produce tunable radiation. Record efficiency and output power (10.5 μW) at a drive frequency of 1.6 THz has been obtained, and SBG radiation was efficiently separated from the laser driver with Si etalons. The power measurements were made using a dual CO2-submillimeter laser system and two Schottky diodes, one as the sideband generator and one as the receiver. The SBG efficiency of four different models of University of Virginia (UVa) diodes were studied and the first measurement of the output mode of the sideband (without the unshifted laser present) was also performed. Finally, confirmation of the optimal parameters for coupling a Gaussian beam into a corner-reflector mounted Schottky diode is presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radiation modes in circular patch antennas

    Publication Year: 1994 , Page(s): 1939 - 1944
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (460 KB)  

    We have formulated exact solutions of the normal modes in the microstrip patch antenna possessing circular geometry. The theory makes use of a new Green's function in conjunction with current potential analysis. The calculations demonstrate that the magnetic wall confinement boundary conditions as formulated in past theories hold approximately true if the surface wave loss is minimal compared to other losses: dielectric loss, conductor loss, and radiation loss. For practical path antennas the normal modes are not confined locally near the microstrip patch. Rather, they are composed of propagation surface waves which extend far beyond the region containing the patch antenna. We term these normal modes as leaky modes, since they resemble the leaky modes found in dielectric image guides. Measurements by us of the radiation mode frequencies and the intrinsic Q-values of the microstrip patch antennas compared very well with theory View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A macroscopic model of nonlinear constitutive relations in superconductors

    Publication Year: 1994 , Page(s): 1951 - 1957
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB)  

    A macroscopic model is proposed for nonlinear electromagnetic phenomena in superconductors. Nonlinear constitutive relations are derived by modifying the linear London's equations. The superelectron number density as a function of applied macroscopic current density, n s(J), is derived from a distribution of electron velocities at a certain temperature T. At temperature T≠0 K, the function ns(J) has a smooth variation near the macroscopic critical current density Jc. Agreement has been found between this n s(J,T) model and the temperature dependence of ns in the two-fluid model. The nonlinear conductivities σs(J) and σn(J) are obtained from the London's equation with the modified ns(J) function. Nonlinear resistance R(I), kinetic inductance Lk(I) and surface impedance Zs(I) in thin wire, slab, and strip geometries are calculated 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