By Topic

Microwave Theory and Techniques, IEEE Transactions on

Issue 3 • Date Mar 1986

Filter Results

Displaying Results 1 - 18 of 18
  • [Front cover - Mar. 1986 [T-MTT]]

    Publication Year: 1986 , Page(s): f1 - f2
    Save to Project icon | Request Permissions | PDF file iconPDF (176 KB)  
    Freely Available from IEEE
  • Interfacial Stress and Excess Noise in Schottky-Barrier Mixer Diodes

    Publication Year: 1986 , Page(s): 342 - 345
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (411 KB)  

    This paper presents evidence linking excess noise in submillimeter-wave Schottky-barrier mixer diodes to stress at the devices' GaAs-SiO2 interface. At the periphery of the Schottky anodes, the SiO2 film is discontinuous and the stress surpasses the GaAs yield stress, resulting in damage to the surrounding material. By modifying the device structure in three independent manners, the stress and damage at the diode periphery were either increased or decreased; in each case, the noise temperature increased or decreased accordingly. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Patent Abstracts (Mar. 1986 [T-MTT])

    Publication Year: 1986 , Page(s): 372 - 375
    Save to Project icon | Request Permissions | PDF file iconPDF (263 KB)  
    Freely Available from IEEE
  • [Advertisement]

    Publication Year: 1986 , Page(s): 376
    Save to Project icon | Request Permissions | PDF file iconPDF (216 KB)  
    Freely Available from IEEE
  • [Back cover - Mar. 1986 [T-MTT]]

    Publication Year: 1986 , Page(s): b1 - b2
    Save to Project icon | Request Permissions | PDF file iconPDF (148 KB)  
    Freely Available from IEEE
  • Numerical Analysis of Various Configurations of Slab Lines (Short Paper)

    Publication Year: 1986 , Page(s): 359 - 363
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (504 KB)  

    Numerical solutions are presented for the characteristic impedance of various line structures derived from the slab line, which allow the calculation also of the even and odd impedance of coupled slab lines. Some approximated formulas are also derived, which match the numerical results with good precision for a large range of geometrical dimensions of the structures. The results presented here are compared with some formulas and numerical results available from previous technical papers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Shunt-Connected Microstrip Radial Stubs (Short Paper)

    Publication Year: 1986 , Page(s): 363 - 366
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB)  

    Radial-line stabs provide an interesting alternative to low-impedance conventional straight stubs.They are useful as filter elements in both series and shunt configurations. In this short paper, the planar circuit analysis previously performed for a series-connected radial stub is extended to the shunt configuration. Theoretical and experimental results are presented to verify the equivalent model for the shunt-connected radial stub. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transient Analysis of a Directional Coupler Using a Coupled Mlcrostrip Slot Line in Three-Dimensional Space (Short Paper)

    Publication Year: 1986 , Page(s): 353 - 357
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    In recent MIC techniques, double-sided MIC has been studied because its advantages in propagation characteristics are greater than that conventional MIC's. A coupled microstrip slotline is one of them. Its application to various circuit elements has often been discussed. But the coupled microstrip slotline is essentially three-dimensional structure, so the analysis demands a rigorous three-dimensional treatment. Also, the recent high-speed pulse technique demands analysis in the time domain. The present paper treats a directional coupler using the coupled microstrip slotline in three-dimensional space and time. The results of the directional coupler analysis is presented with the complicated time variation of the three-dimensional electromagnetic field. So, the mechanism of the directional coupling phenomena that is produced by the propagation characteristics of the even and odd modes is presented in the time domain, In particular, the instantaneous diagram of the Poynting vector details the energy flow in the transient process. For the analysis of the characteristics of the complex microwave device, these results present the utilities of the various field distributions that are obtained by the three-dimensional vector analysis in the time domain. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Focused Heating In Cylindrical Targets-Part II (Short Paper)

    Publication Year: 1986 , Page(s): 357 - 359
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    We implement the analytical formulation for the local power dissipated in a conductive target of cylindrical form that was described in Part I. The scheme employs a number N of horn apertures arranged around the periphery of the target. We show sample results for the radial and the azimuthal variations of the normalized local power. The cases where the array is focused at both the center of the target and where it is focused at an eccentric point are considered for N = 4, 8, and 16. It is shown that the unwanted secondary "hot spots" can be eliminated if the number N of horn apertures is increased sufficiently. The results are relevant to microwave thermic heating in cancer therapy. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Excitation of Waveguide by Stripline- and Microstrip-Line-Fed Slots

    Publication Year: 1986 , Page(s): 321 - 327
    Cited by:  Papers (8)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (664 KB)  

    This paper presents investigations on coupling between stripline/microstrip line and a rectangular waveguide coupled through a slot in the ground plane which is fixed in the cross-sectional plane of the waveguide. A closed-form expression for the impedance loading on stripline/microstrip line is evaluated from knowledge of the complex power flowing down the rectangular waveguide supporting the dominant mode and discontinuity in the modal voltage in stripline/microstrip line. The reactance cancellation is obtained by terminating the stripline/microstrip tine exciting the slot in a short-circuited stub. The structure under this condition forms a transition between stripline/microstrip line and a waveguide. The design curves on slot length versus frequency are presented for different values of dielectric constants. The variation of coupling as a function of frequency and also the location of the slot is evaluated. Numerical results for slot coupling useful for the design of waveguide simulators are also presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Magnetostatic Surface-Wave Propagation in Ferrite Thin Films with Arbitrary Variations of the Magnetization through the Film Thickness (Correction)

    Publication Year: 1986 , Page(s): 371
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (50 KB)  

    Equation of the above paper should read as follows. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Small-Signal Second-Harmonic Generation by a Nonlinear Transmission Line (Short Paper)

    Publication Year: 1986 , Page(s): 351 - 353
    Cited by:  Papers (20)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB)  

    Second-harmonic generation (SHG) by a relatively low-loss transmission line having a capacitive nonlinearity is treated with an extended small-signal analysis. This simple theory brings out the relevance of "phase matching" the fundamental- and second-harmonic waves and of reducing losses in order to optimize SHG. It is shown that maximum SHG will occur when the line is short compared with its "coherence length" and has radian electrical length equal to twice its "transmission Q" at the second-harmonic frequency. The product of a line's "transmission Q" and its "nonlinearity factor" should be maximized to obtain maximum efficiency and is, therefore, believed to be a useful figure of merit for comparing the SHG potential of different transmission-line implementations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of Propagation Constants and Cutoff Frequencies of Radially Inhomogeneous Optical Fibers

    Publication Year: 1986 , Page(s): 328 - 332
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    Based on the finite-difference technique, an efficient numerical method that can treat both the propagation constants and cutoff frequencies of optical fibers with arbitrary permittivity profiles is developed in the rigorous vector form. Such a propagation problem is formulated in transverse fields so that the proposed method does not suffer from spurious modes. The associated boundary conditions including those at cntoff are derived in a novel way. Thereafter, numerical results of the cutoff frequency and propagation constant of a fiber with the parabolic profile are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Theory and Performance of a Power-Combining Multiple-Device Ladder Amplifier

    Publication Year: 1986 , Page(s): 333 - 341
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (832 KB)  

    This paper presents a detailed discussion on the microwave power amplification using a multiple-device ladder structure which is essentially an array of diode-mount-pairs in a rectangular waveguide cavity. For both transmission and reflection types, the capability of perfect combining of available powers from each component device and available input signal power is analytically described. A power flow distribution along the structure is also described to interpret the power-combining mechanism. Amplifier characteristics are studied through numerical analysis and well confirmed by experiments on X-band amplifiers with up to eight Gunn diodes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Broad-Band Analysis of a Coaxial Discontinuity Used for Dielectric Measurements

    Publication Year: 1986 , Page(s): 346 - 350
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    A coaxial line terminated by a gap is considered, the gap being filled with an unknown material. This cell enables measurements of complex permittivity of dielectric materials to be made. The relationship linking the measured admittance to the dielectric properties is obtained from a theoretical analysis of the electromagnetic field in the tine. The equivalent-circuit parameters of a coaxial line terminated by a gap are obtained all higher order waves excited at the discontinuity are taken into account. The measurements show good agreement between measured and calculated data from dc to 12.4 GHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Hybrid-Mode Analysis of Coupled Microstrip-Slot Resonators (Comments)

    Publication Year: 1986 , Page(s): 369 - 371
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (272 KB)  

    We were interested to read the above paper, but it calls for a remark concerning the extension of the hybrid-mode analysis to coupled microstrip-slot resonator. In fact, when the coupled strips are very close to each other, the basis functions used in the above paper does not allow one to obtain a satisfactory resonant frequency. To do so, we must necessary increase the number of basis function by using symmetric and antisymmetric basis functions with respect to the axis of a strip. In this case, we must be sure that the criterion of relative convergence is satisfied. Furthermore, the mathematical developments of this hybrid-mode analysis have been already published by the same author. So it would have been better to focus the purpose of the above paper on the problem more specific to the coupling of the two strips. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spectral Domain Analysis of an Elliptical Microstrip Ring Resonator (Comments)

    Publication Year: 1986 , Page(s): 369
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB)  

    Along with the above paper several other papers have been published recently by Sharma and his co-workers [2]-[3] on the analysis of the resonant frequencies of a microstnp disk using the quasi-static approach. The quasi-static approach has been proven to be incorrect in [4] and [5]. The quasi-static argument on the correction to the resonant frequencies of a microstrip disk is based on some intuitive arguments that are not rigorous. The only thing it predicts correctly is that the resonant frequencies of a microstrip disk should decrease compared to that of a magnetic-wall model. The author may argue that since the correction to the magnetic-wall model is small, any approximate method is viable. However, we have found that the quasi-static correction could be as much as 50 percent in error. Even when this correction is small, if we bother to caIculate it, I think we should calculate it correctly. The author's quasi-static correction has a new twist compared to earlier authors, but when epsilonr = 1, it does not differ from the quasi-static correction of earlier work. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Effects of Attenuation on the Born Reconstruction Procedure for Microwave Diffraction Tomography (Short Paper)

    Publication Year: 1986 , Page(s): 366 - 368
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB)  

    The effects of attenuation on the Born inversion process for diffraction tomography are investigated. The exact forward scattered fields for a Iossy dielectric cylinder in a Iossy medium are calculated and are then used to reconstruct an image of the scattering object. As accurate image is produced only when the cylinder acts as a small perturbation on the dielectric constant of the external medium. Results indicate that even small losses have a significant effect on the resolution of the image. It is possible, however, to eliminate image distortion by matching the loss tangent of the outside medium to that within the cylinder. 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