Showing papers in "IEEE Transactions on Microwave Theory and Techniques in 1984"
TL;DR: The history of power transmission by radiowaves is reviewed from Heinrich Hertz to the present time with emphasis upon the free-space microwave power transmission era beginning in 1958 as mentioned in this paper.
Abstract: The history of power transmission by radiowaves is reviewed from Heinrich Hertz to the present time with emphasis upon the free-space microwave power transmission era beginning in 1958. The history of the technology is developed in terms of its relationship to the intended applications. These include microwave powered aircraft and the Solar Power Satellite concept.
1,562 citations
TL;DR: In this article, the results of computer simulations used to determine the domains of applicability of the first-order Born and Rytov approximations in diffraction tomography for cross-sectional (or three-dimensional) imaging of biosystems are shown.
Abstract: In this paper, the results of computer simulations used to determine the domains of applicability of the first-order Born and Rytov approximations in diffraction tomography for cross-sectional (or three-dimensional) imaging of biosystems are shown. These computer simulations were conducted on single cylinders, since in this case analytical expressions are available for the exact scattered fields. The simulations establish the first-order Born approximation to be valid for objects where the product of the relative refractive index and the diameter of the cylinder is less than 0.35 lambda. The first-order Rytov approximation is valid with essentially no constraint on the size of the cylinders; however, the relative refractive index must be less than a few percent. We have also reviewed the assumptions made in the first-order Born and Rytov approximations for diffraction tomography. Further, we have reviewed the derivation of the Fourier Diffraction projection Theorem, which forms the basis of the first-order reconstruction algorithms. We then show how this derivation points to new FFT-based implementations for the higher order diffraction tomography algorithms that are currently being developed.
590 citations
TL;DR: In this paper, the capacitance matrix and inductance matrix for a multiconductor transmission line in a multilayered dielectric region is presented, where the conductors are either above a single ground plane or between two parallel ground planes.
Abstract: A method for computing the capacitance matrix and inductance matrix for a multiconductor transmission line in a multilayered dielectric region is presented. The number of conductors and the number of dielectric layers are arbitrary. Some of the conductors may be of finite cross section and others may be infinitesimally thin. The conductors are either above a single ground plane or between two parallel ground planes. The formulation is obtained by rising a free-space Green's function in conjunction with total charge on the conductor-to-dielectric interfaces and polarization charge on the dielectric-to-dielectric interfaces. The solution is effected by the method of moments using pulses for expansion and point matching for testing. Computed results are given for some cases where all conducting lines are of finite cross section and other cases where they are infinitesimally thin.
445 citations
TL;DR: In this article, the analysis of GaAs MESFET distributed amplifiers and a systematic approach to their design are presented, focusing on fundamental design considerations and also establishing the maximum gain-bandwidth product of the amplifier.
Abstract: In the paper, the analysis of GaAs MESFET distributed amplifiers and a systematic approach to their design are presented. The analysis focuses on fundamental design considerations and also establishes the maximum gain-bandwidth product of the amplifier.The design approach presented enables one to examine the tradeoffs between the variables, such as the device, the number of devices, and the impedances and cutoff frequency of the lines, and arrive at a design which gives the desired frequency response. Excellent agreement is shown when the theoretically predicted response of a typical amplifier is compared with computer-aided analysis results, and good agreement is shown with previously published experimental results.
349 citations
TL;DR: In this paper, a vector H-field formulation is developed for electromagnetic wave propagation for a wide range of guided-wave problems, which is capable of solving microwave or optical waveguide problems with arbitrarily anisotropic materials.
Abstract: A vector H-field formulation is developed for electromagnetic wave propagation for a wide range of guided-wave problems. It is capable of solving microwave or optical waveguide problems with arbitrarily anisotropic materials. We have introduced infinite elements to extend the region of explicit field representation to infirdly, to consider open-type waveguides more accurately. Computed results are given for a variety of optical planar guides, image lines, and waveguides containing skew anisotropic dielectic.
293 citations
TL;DR: In this article, a penalty function method was introduced to the finite element formulation, to reduce or eliminate spurious solutions, which also improved the quality of the physical field solutions, and was applied for the solution of metallic homogeneous and inhomogeneous guides, and integrated optics guides.
Abstract: The finite element method is a well-established method for the solution of a wide range of guided wave problems. One drawback associated with the powerful vector formulation is the appearance of spurious or nonphysical solutions. A penalty function method has been introduced to the finite element formulation, to reduce or eliminate spurious solutions. It also improves the quality of the physical field solutions. The method has been applied for the solution of metallic homogeneous and inhomogeneous guides, and integrated optics guides.
283 citations
TL;DR: In this article, closed-form expressions are presented which model the frequency-dependent even and odd-mode characteristics of parallel coupled microstrip lines with hitherto unattained accuracy and range of validity.
Abstract: In this paper, closed-form expressions are presented which model the frequency-dependent even- and odd-mode characteristics of parallel coupled microstrip lines with hitherto unattained accuracy and range of validity. They include the effective dielectric constants, the characteristic impedances using the power-current formulation, as well as the open-end equivalent lengths for the two fundamental modes on coupled microstrip. The formulas are accurate into the millimeter-wave region. They are based on an extensive set of accurate numerical data which were generated by a rigorous spectral-domain hybrid-mode approach and are believed to represent a substantial improvement compared to the state-of-the-art and with respect to the computer-aided design of coupled microstrip filters, directional couplers, and related components.
276 citations
TL;DR: In this article, electric and magnetic field patterns for five of the lowest resonant modes in cylindrical dielectic resonators are displayed in various planes of intersection, based on a method moments solution of the surface integral equation for bodies of revolution.
Abstract: Electric- and magnetic-field patterns for five of the lowest resonant modes in cylindrical dielectic resonators are displayed in various planes of intersection. The computational procedure is based on a method moments solution of the surface integral equation for bodies of revolution. Improvement of the numerical stability through the normalization of the matrix is discussed, and an algorithm for the evaluation of the modal field components is described.
261 citations
TL;DR: The development of microwave heating applications is reviewed in this article, with a focus on the application of lower RF frequencies to induction and dielectric heating, followed by a broadening of interest to include scientific and industrial applications.
Abstract: The development of microwave heating applications is reviewed. This field has followed the earlier application of lower RF frequencies to induction and dielectric heating. Serious activity began after World War II, directed towards a microwave oven for commercial and residential use. The broadening of interest to include scientific and industrial applications followed in the early sixties as new markets for microwave power sources were sought. The creation of the International Microwave Power Institute was one result. The marketing of a countertop microwave oven for consumers gave birth to the economically important oven business in the sixties. The growth of this field has been marked, perhaps slowed, by a series of sociotechnical events questioning the safety of microwave exposure near high-power microwave systems. Although some of this has receded, a problem of public education remains for those who will expand this field. The future development of this field will exploit a broader number of operating frequencies and will be ultimately limited by environmental regulations related to electromagnetic compatibility (or RFl), rather than safe exposure of biological tissue.
253 citations
TL;DR: Ginzton's impedance method of Q-factor measurement is adapted to network analyzer techniques as mentioned in this paper, where the circuit model of the resonator incorporates also an external reactance which varies linearly with frequency to take into account the effects of the coupling mechanism and the influence of distant resonant modes.
Abstract: Ginzton's impedance method of Q-factor measurement is adapted to network analyzer techniques. The circuit model of the resonator incorporates also an external reactance which varies linearly with frequency to take into account the effects of the coupling mechanism and the influence of the distant resonant modes.
238 citations
TL;DR: In this article, the authors used dispersive Fourier transform spectroscopy applied to a modular two-beam polarization interferometer to obtain high-resolution millimeter-wave (5 to 1/2 mm) continuous spectra on complex refractive index, complex dielectric permittivity, and loss tangent for a variety of materials.
Abstract: It is no longer necessary to use extrapolated microwave dielectric data when designing millimeter-wave components, devices, and systems. Precision measurements can now be made to generate highly accurate millimeter-wave (5 to 1/2 mm) continuous spectra on complex refractive index, complex dielectric permittivity, and loss tangent for a variety of materials such as common ceramics, semiconductors, crystalline, and glassy materials. The continuous spectra reveal an increase in dielectric loss with increase in frequency in this wavelength range for most materials. Reliable measurements also reveal that the method of preparation of nominally identical specimens can change the dielectric losses by many factors. These broad-band measurements were carried out employing dispersive Fourier transform spectroscopy applied to a modular two-beam polarization interferometer. Data obtained with Fabry-Perot open resonator methods at wavelengths of 5 mm and longer will also be compared.
TL;DR: In this paper, an account of the development of microwave filters is surveyed, commencing from 1937, and all types of filter characteristics are surveyed, such as Chebyshev, elliptic and pseudo-elliptic function, Achieser-Zolotarev, and a variety of generalized designs, including linear phase.
Abstract: An account of the development of microwave filters is surveyed, commencing from 1937. Much of the foundation of modem filter theory and practice took place during the period of World War II and the years immediately following, especially by such pioneers as the late P. I. Richards, whose subsequent career is briefly described. Filter topics discussed include low-pass, bandpass, high-pass, and multiplexers constructed in a variety of media such as waveguide, coaxial line, microstrip, and stripline, as well as dielectric resonators. All types of filter characteristics are surveyed, such as Chebyshev, elliptic and pseudo-elliptic function, Achieser-Zolotarev, and a variety of generalized designs, including linear phase.
TL;DR: In this paper, an application of the boundary element method to two-dimensional electromagnetic field problems has been proposed, where calculations can be performed using far fewer nodes than by the finite element method, and unbounded field problems are easily treated without special additional consideration.
Abstract: This paper proposes an application of the boundary-element method to two-dimensional electromagnetic field problems. By this method, calculations can be performed using far fewer nodes than by the finite-element method, and unbounded field problems are easily treated without special additional consideration. In addition, the results obtained have fairly good accuracy. In this paper, analyzing procedures of electromagnetic field problems by the boundary-element method, under special conditions, are proposed and several examples are investigated.
TL;DR: In this article, a method for computing the electrostatic fields and the capacitance matrix for a multiconductor system in a multiple dielectric region is presented, where the conductors can be either above a single ground plane or between two parallel ground planes.
Abstract: A method for computing the electrostatic fields and the capacitance matrix for a multiconductor system in a multiple dielectric region is presented. The number of conductors and the number of dielectrics in this analysis are arbitrary. Some of the conductors maybe of finite volume and others may be infinitesimally thin. The conductors can be either above a single ground plane or between two parallel ground planes. The formulation is obtained by using a free-space Green's function in conjunction with total charge on the conductor-to-dielectric interfaces and polarization charge on the dielectric-to-dielectric interfaces. The solution is effected by the method of moments using triangular subdomains with piecewise constant expansion functions and point matching for testing. Computed results are given for some finite-length conducting lines, compared to previous results obtained by two-dimensional analysis.
TL;DR: In this paper, a method for analyzing arbitrarily shaped planar microwave structures, based on the method of lines, is presented. But this method is not applicable to both resonant and periodic structures in microstrip, slotline, and finline circuits.
Abstract: This paper presents a method for analyzing arbitrarily shaped planar microwave structures, which is based on the method of lines and applies to both resonant and periodic structures in microstrip, slotline, and finline circuits. Numerical results are presented for some selected structures.
TL;DR: In this paper, a new circuit concept which significantly improves the power-handling capability of a traveling-wave amplifier by coupling the active devices to the input gate line through discrete series capacitors is described.
Abstract: A new circuit concept which significantly improves the power-handling capability of a traveling-wave amplifier by coupling the active devices to the input gate line through discrete series capacitors is described. The approach is applied to a 1-W, 2-8-GHz monolithic amplifier design.
TL;DR: In this paper, a finite-element analysis in which nonphysical spurious solutions do not appear has been established to solve the electromagnetic field problem of the closed waveguide filled with various anisotropic media.
Abstract: A finite-element analysis in which nonphysical spurious solutions do not appear has been established to solve the electromagnetic field problem of the closed waveguide filled with various anisotropic media. This method is based on the approximate extremization of a functional, whose Euler equation is the three-component curlcurl equation derived from the Maxwell equations, with a new conforming element. Specific examples are given and the results are compared with those obtained by exact solutions and longitudinal two-component finite-element solutions. Very close agreement was found and all nonzero eigenvalues have been proved to have one-to-one correspondence to the propagating modes of the waveguide.
TL;DR: In this article, a numerical method for determining the modes of a rectanguIar or a circular waveguide strongly perturbed by axial cylindrical conducting objects is presented, based upon an integral equation which leads to a matrix eigenvalue problem by using the Galerkin procedure.
Abstract: A numerical method for determining the modes of a rectanguIar or a circular waveguide strongly perturbed by axial cylindrical conducting objects is presented. The method is based upon an integral equation which leads to a matrix eigenvalue problem by using the Galerkin procedure. Cutoff wavenumbers are simultaneously calculated with very good precision for a number of modes near to the order of the matrix eigenvalue problem. Excellent results are obtained also when the perturbed waveguide section exhibits reentrant parts or edges. Computing time is short and storage requirements are moderate. The method is also applicable for waveguides of arbitrary cross section.
TL;DR: In this paper, a review of the major events in the development of millimeter-and sub-millimeter-wave technology from its beginnings in the 1890's until the present time is presented.
Abstract: In this review an attempt is made to identify many of the major events that have occurred in the development of millimeter- and submillimeter-wave technology from its beginnings in the 1890's until the present time. The review is not intended to be the definitive history of the field, but may form the basis for someone to later write a more comprehensive or encyclopedic version. The history conveniently divides into three periods: 1890 through World War II, Post War (1947 to 1965), and Modern Age (after 1965).
TL;DR: In this paper, a method for computing the modes of dielectric guiding structures based on finite differences is described, and the numerical computation program is efficient and can be applied to a wide range of problems.
Abstract: A method for computing the modes of dielectric guiding structures based on finite differences is described. The numerical computation program is efficient and can be applied to a wide range of problems. We report here solutions for circular and rectangular dielectric waveguides and compare our solutions with those obtained by other methods. Limitations in the commonly used approximate formulas developed by Marcatili are discussed.
TL;DR: In this article, a planar structure having arbitrarily located conductor lines immersed in complex anisotropic media presents one with a very general guided wave problem, which is solved by a rigorous formulation technique characterizing each layer by a 6 x 6 tensor and finding the appropriate Fourier transformed Green's function matrix G of 2n x 2n size.
Abstract: A planar structure having arbitrarily located conductor lines immersed in complex anisotropic media presents one with a very general guided wave problem. This problem is solved here by a rigorous formulation technique characterizing each layer by a 6 x 6 tensor and finding the appropriate Fourier transformed Green's function matrix G of 2n x 2n size. From G, a method-of-moments solution for the propagation characteristics follows, including propagation constant eigenvalues and field eigenvectors at all spatial Iocations. The method is very versatile and can handle a huge class of microwave or millimeter-wave integrated circuit or monolithic circuit problems, no matter how simple or complex as long as they possess planar symmetry.
TL;DR: In this article, the important numerical models are reviewed and possibilities for future development are discussed, as well as possible future development of numerical models for predicting the thermal response after exposure to electromagnetic (EM) radiation.
Abstract: For humans exposed to electromagnetic (EM) radiation, the resulting thermophysiologic response is not well understood. Because it is unlikely that this information will be determined from quantitative experimentation, it is necessary to develop theoretical models which predict the resultant thermal response after exposure to EM fields. These calculations are difficult and involved because the human thermoregulatory system is very complex. In this paper, the important numerical models are reviewed and possibilities for future development are discussed.
TL;DR: In this article, a procedure for producing accurate and unique small-signal equivalent circuit models for carrier-mounted GaAs FET's is presented, which utilizes zero drain-source bias S parmeter tests to determine accurate values of carrier parasitics, and dc measurements to evaluate the FETs gate, source, and drain resistances.
Abstract: A procedure has been developed for producing accurate and unique small-signal equivalent circuit models for carrier-mounted GaAs FET's. The procedure utilizes zero drain-source bias S parmeter tests to determine accurate values of carrier parasitics, and dc measurements to evaluate the FET's gate, source, and drain resistances. Subsequent S-parameter measurements at full bias are then used to resolve the FET into an equivalent circuit model that has only 8 unknown elements out of a possible 16. A technique for evaluating the frequency range of accurate data is presented and the FET model shown is useful well above the maximum frequency of measurement. Examples of device diagnostics are presented for RCA flip-chip mounted GaAs FET's.
TL;DR: In this article, the reflection coefficient for an inductive strip is obtained by cascading two scattering matrices separated by a distance equal to the stripwidth, which is valid up to moderate bandwidths, except for the narrowband design at the higher waveguide frequency range.
Abstract: Waveguide E-plane filters with all-metal inserts are designed by a procedure based on the reflection coefficients of axial inductive strips. The scattering matrix, representing the junction in a bifurcated waveguide, is calculated by a mode-matching method. The reflection coefficient for an inductive strip is then obtained by cascading two scattering matrices separated by a distance equal to the stripwidth. The design is valid up to moderate bandwidths, except for the narrowband design at the higher waveguide frequency range, where both the center frequency and the bandwidth are inaccurate. Possible sources of error are studied and a method minimizing the error is proposed.
TL;DR: The history of microwave filters is covered by the coauthors in a companion paper, while certain other passive components are touched on in the other historical review papers in this issue as discussed by the authors, and then, because of space limitations, this paper concentrates on the important sub-field of directional couplers.
Abstract: After Hertz verified Maxwell's electromagnetic wave theory using a spark-gap microwave source, activity in the microwave range was negligible until about 1930, and quite limited until 1939. In that year, an explosion of activity commenced, motivated by military needs for radar and the invention of the high-power pulsed magnetron. Microwave passive component development during World War II (1939- 1945) is discussed briefly, and then, because of space limitations, this paper concentrates on the important sub-field of directional couplers. The history of microwave filters is covered by the coauthors in a companion paper, while certain other passive components are touched on in the other historical review papers in this issue.
TL;DR: In this article, a dual-mode conical horn has been developed and tested at 0.5, 1.4, 3.1, and 34.2 mm, where the waveguide reflection loss and the phase center have been determined.
Abstract: A simple dual-mode conical horn has been developed and tested at 0.5, 1.4, 3.1, and 34.2 mm. The horn has nearly equal beam shape in the E and H plane far field patterns with a 3-dB half angle of 6°. At 34.2 mm, the waveguide reflection loss and the phase center have been determined.
TL;DR: In this paper, a novel iterative approach for calculations of specific absorption rate (SAR) distributions in arbitrary, lossy, dielectric bodies is described, which can be extended to 3D bodies with N = 10/sup 4/to 10/ sup 5/ cells allowing, thereby, details of SAR distributions that are needed for EM hyperthermia, as well as for assessing biological effects.
Abstract: The paper describes a novel iterative approach for calculations of specific absorption rate (SAR) distributions in arbitrary, lossy, dielectric bodies. To date, the method has been used for 2-D problems where its accuracy has been confirmed by comparison with the analytic solutions for homogeneous and layered, circular, cylindrical bodies. With computation times that are proportional to N log/sub 2/N rather than N/sup 2/ to N/sup 3/ for the method of moments, the present approach should be extendable to 3-D bodies with N= 10/sup 4/to 10/sup 5/ cells allowing, thereby, details of SAR distributions that are needed for EM hyperthermia, as well as for assessing biological effects.
TL;DR: In this article, two conducting or magnetic planes are inserted at some distances away from the discontinuity so as to obtain a closed resonant structure, and a transverse resonance technique is then used to compute the resonant frequencies and, from these, the equivalent circuit parameters of the finline discontinuity.
Abstract: A method of analysis is proposed for characterizing finline discontinuities. Two conducting or magnetic planes are inserted at some distances away from the discontinuity so as to obtain a closed resonant structure. A transverse resonance technique is then used to compute the resonant frequencies and, from these, the equivalent circuit parameters of the discontinuity. In the particular case when the discontinuity is removed, the method can be used to characterize uniform finlines.
TL;DR: In this article, a multiconductor transmission line in a multilayered dielectric medium can be characterized by four matrix parameters the capacitance matrices, the inductance matrix, the shunt conductance matrix and the series resistance matrix.
Abstract: For the transmission-line modes, a multiconductor transmission line in a multilayered dielectric medium can be characterized by four matrix parameters the capacitance matrices [C], the inductance matrix [L], the shunt conductance matrix [G], and the series resistance matrix [R]. The first two matrices [C] and [L] can be obtained from equivalent electrostatic and magnetostatic problems. The conductance matrix [G] can be obtained by changing all dielectric constants epsilon/sub i/ to complex dielectric constants /angle over epsilon/sub i/ in the equivalent electrostatic problem. The resistance matrix [R] can be obtained by applying a perturbation method to each mode of the transmission line. A computer program has been written for an arbitrary line, and sample computations are presented.
TL;DR: In this article, the authors present an analysis of a low-noise dielectric resonator GaAs FET oscillator in a frequency-locked loop (FLL), which is used for FM noise degeneration.
Abstract: This paper presents an analysis of a low-noise dielectric resonator GaAs FET oscillator in a frequency-locked loop (FLL), which is used for FM noise degeneration. In this circuit, one resonator serves both as the frequency-determining element of the oscillator and as the dispersive element of the discriminator. The results of the analysis are used to generate design guidelines. These guidelines were followed in an experimental realization of an X-band circuit. The measured FM noise was--120 and--142 dBc/Hz at 10- and 100-kHz offset frequencies, respectively, and corresponded closely to predicted results.