By Topic

Microwave Theory and Techniques, IEEE Transactions on

Issue 7 • Date Jul. 1985

Filter Results

Displaying Results 1 - 21 of 21
  • [Front cover - Jul. 1985 [T-MTT]]

    Publication Year: 1985 , Page(s): f1 - f2
    Save to Project icon | Request Permissions | PDF file iconPDF (171 KB)  
    Freely Available from IEEE
  • A New Four-Port Automatic Network Analyzer: Part I - Description and Performance

    Publication Year: 1985 , Page(s): 563 - 568
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (583 KB)  

    A four-port automatic network analyzer based upon a new concept has been tested in the 8-12-GHz range. An essential feature of this analyzer, compared with the six-port systems, is that only one detector is used, and one electronically adjustable reference load is added. In this paper, an electronically adjustable short circuit is used as the reference load. Hence, the analyzer is comparatively simple and compact since only a few components are required. Moreover, the quality of the components can be moderate. A small desk-top computer (HP 85) is satisfactory for handling measurement data, adjusting the short circuit, and presenting the result. A simplified theory required for the calibration and measurement procedure for the determination of the magnitude and the phase of an unknown load is included in this report, and experiments illustrate how the accuracy is improved when the calibration is gradially refined. The expected accuracy of the network analyzer is discussed in some detail. The simple design and the moderate demands on the component quality means that it should be ideal for millimeter-wave frequencies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A New Four-Port Automatic Network Analyzer: Part II - Theory

    Publication Year: 1985 , Page(s): 569 - 575
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (454 KB)  

    This paper presents a comprehensive theory of the new four-port network analyzer using only one power detector and one electronically adjustable reference load, (e.g., an adjustable short circuit or a varactor diode) described in a companion paper. A method based on annihilation operators for describing an n-port is introduced. This method is found convenient for analyzing different measurement situations. Hence, schemes for reflection measurements and transmission measurements are analyzed in detail. For evaluation of the reflection (or transmission) coefficient, it is shown that seven (or five) parameters defining the system have to be determined. Calibration schemes for precision reflection and transmission measurements are described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Continuously Tunable 65 - 15-GHz Gunn Oscillator

    Publication Year: 1985 , Page(s): 610 - 619
    Cited by:  Papers (26)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (952 KB)  

    A phase-locked second harmonic Gunn oscillator, mechanically tunable from 65 to 115 GHz, has been developed for use as a Iocal oscillator (LO) in millimeter radio astronomy. The oscillator's output power is greater than 2 mW over most of its operating range, and exceeds 10 mW from 80 to 102 GHz. Its frequency can be electronically tuned approximately +-200 MHz by varying the bias voltage on the Gunn diode it is phase locked by exploiting this bias tuning. The oscillator consists of a commercially available, packaged GaAs Gunn diode which is mounted in a coaxial resonator of adjustable length. Descriptions of the mechanical design and phase-lock circuit are given. Extensive experimental measurements of the tuning range and power output for oscillators with different resonator dimensions also are reported. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Patent Abstracts (Jul. 1985 [T-MTT])

    Publication Year: 1985 , Page(s): 660 - 663
    Save to Project icon | Request Permissions | PDF file iconPDF (328 KB)  
    Freely Available from IEEE
  • Membership application

    Publication Year: 1985 , Page(s): 664
    Save to Project icon | Request Permissions | PDF file iconPDF (89 KB)  
    Freely Available from IEEE
  • IEEE Microfilm (Jul. 1985 [T-MTT])

    Publication Year: 1985 , Page(s): 665
    Save to Project icon | Request Permissions | PDF file iconPDF (283 KB)  
    Freely Available from IEEE
  • IEEE Press Books [advertisement]

    Publication Year: 1985 , Page(s): 666
    Save to Project icon | Request Permissions | PDF file iconPDF (148 KB)  
    Freely Available from IEEE
  • [Back cover - Jul. 1985 [T-MTT]]

    Publication Year: 1985 , Page(s): b1 - b2
    Save to Project icon | Request Permissions | PDF file iconPDF (144 KB)  
    Freely Available from IEEE
  • Circuit Analysis and Design of Radial Pretuned Modules Used for Millimeter-Wave Oscillators

    Publication Year: 1985 , Page(s): 600 - 609
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (920 KB)  

    This paper summarizes the use of the radial pretuned module for the realization of millimeter-wave IMPATT or Gunn oscillators. Circuit analysis and derivation of an analytical model for the prediction of the characteristics of this type of oscillator are reviewed and the design of optimal structures is reported. Experimental results are also presented in order to justify the assumptions, which have been done to determine the range of validity of this model. This is done either by direct measurements or by the study of the behavior of millimeter-wave oscillators. Finally, we summarize the typical results obtained with this modular approach and its advantages versus classical ones. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microwave Measurement of Dielectric Properties of Low-Loss Materials by the Dielectric Rod Resonator Method

    Publication Year: 1985 , Page(s): 586 - 592
    Cited by:  Papers (80)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (880 KB)  

    Improvements both in accuracy and speed are described for the technique of measuring the microwave dielectric properties of low-loss materials by using a dielectric rod resonator short-circuited at both ends by two parallel conducting plates. A technique for measuring the effective surface resistance Rs of the conducting plates is proposed to allow the accurate measurement of the loss tangent tan delta. By means of the first-order approximation, the expressions are analytically derived for estimating the errors of the measured values of relative permittivity epsilonr, tan delta, and Rr, for measuring the temperature coefficient of epsilonr, and for determining the required size of the conducting plates. Computer-aided measurements are realized by using these expressions. It is shown that the temperature dependence of Rs, should be considered in the tan delta measurement. The copper plates used in this experiment have the relative conductivity of 91.0+-2.7 percent at 20°C, estimated from the measured Rs value. For a 99.9-percent alumina ceramic rod sample, the results measured at 7.69 GHz and 25°C show that epsilonr,= 9.687+-0.003 and tan delta = (1.6+-0.2)x 10-5. The temperature coefficients measured between 25 and 100°C are 112x10-6/°C for epsilonr, and 23x10-4/°C for tan delta. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stability of the Oscillation Mode in a Multiple-Oscillator System

    Publication Year: 1985 , Page(s): 593 - 599
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (624 KB)  

    By using the Rieke diagram in terms of traveling waves, we discuss the stability conditions for an oscillation mode in a multiple-oscillator system which clearly indicate the reason why it is difficult for a multiple-oscillator system to obtain a single-mode operation. Further, we proposed a combining power system of oscillators which can give a stable operation free from the moding problem. Experimental observations are found to be in good agreement with the conclusions of the analytical approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Finite-Element Method for Finding Modes of Dielectric-Loaded Cavities (Short Papers)

    Publication Year: 1985 , Page(s): 635 - 639
    Cited by:  Papers (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (440 KB)  

    A three-dimensional high-order finite-element scheme is proposed for finding the modes of dielectric-loaded cavities of arbitrary shape. New light is shed on the presence of spurious solutions. Results for an empty rectangular box are compared with exact solutions, A loaded rectangular box is also analyzed. 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 I (Short Papers)

    Publication Year: 1985 , Page(s): 647 - 649
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    The analytical basis of a method to focus the electromagnetic power into a conductive cylinder is described. The scheme, & currently being used by others, is to locate a number of horn apertures around the periphery. An explicit expression is obtained for the required excitation of the apertures for a two-dimensional model. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of Asymmetric Coupled Striplines (Short Papers)

    Publication Year: 1985 , Page(s): 643 - 646
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    A unified method for the quasi-static and the hybrid-mode formulation of asymmetric coupled striplines is presented. Variational expressions are derived for the matrix elements, which describe the quasistatic characteristics, for the first time. A very accurate numerical method is shown and some numerical examples are presented for the different types of asymmetric coupled striplines with anisotropic substrates. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Circuit Design of the Loaded-Line Phase Shifter

    Publication Year: 1985 , Page(s): 626 - 634
    Cited by:  Papers (37)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (872 KB)  

    Circuit design procedures for the loaded-line phase shifter are presented, utilizing a phasor diagram representation of the line to identify its loading modes. The effects of losses in the loading elements on the circuit parameters are determined and design factors affecting bandwidth are discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Finite-Element Analysis of Dielectric Waveguides with Curved Boundaries

    Publication Year: 1985 , Page(s): 576 - 585
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB)  

    The modes of dielectric waveguides with curved boundaries are computed efficiently using a curved-sided (isoparametric) second-order finite element rather than the more usual triangular element. A novel way of placing the virtual boundary is described. Results are obtained for dielectric rod and elliptical waveguides, and compared with earlier results. The method is used to analyze a single-mode fiber-optical coupler. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Large-Signal Microwave Performance Prediction of Dual-Gate GaAs MESFET Using an Efficient and Accurate Model (Short Paper)

    Publication Year: 1985 , Page(s): 639 - 643
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (480 KB)  

    This paper presents a microwave large-signal model for the dual-gate MESFET. The model enables prediction of device performance in small-signal and large-signal circuits. The model is an extension of a previously developed model for the ordinary MESFET. It relies on basic principles, thus correlating the device geometry and physical parameters to its performance. The speed and accuracy of the model are demonstrated by calculating three types of device performance: dc curves smell-signal scattering parameters, and huge-signal simulation of an amplifier. Good agreement was achieved between calculated and measured perfomance. The computed results are presented for comparison only, and no attempt was made to present a comprehensive analysis of the device performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Linearity Limits of the Varactor-Controlled Osc-Mod Circuits

    Publication Year: 1985 , Page(s): 620 - 625
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    A method for optimum selection of the natural frequencies of a varactor-controlled oscillator (osc-mod) is developed for the purpose of providing the best modulation linearity, while still retaining practical features such as continuous tuning. Highly linear operation was found to be possible using conventional abrupt varactors if the circuit has one pole and two zeros situated below the operating frequency. The limits of the maximum realizable modulation bandwidths are established for a linearity of one percent, with and without the requirement for continuous tuning. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • E-Plane Integrated Parallel-Strip Screen Waveguide Filters (Short Papers)

    Publication Year: 1985 , Page(s): 654 - 659
    Cited by:  Papers (4)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (664 KB)  

    A rigorous field theory design of a class of rectangular waveguide screen fiIters is presented which achieves improved attenuation in the upper stopband. The method of field expansion into suitable eigenmodes used considers the effects of the finite rectangular E-plane grid thickness and the mutual higher order mode interaction of the single screens. Calculated results up to 55 GHz show that the peak attenuation in the upper stopband for a Ka-band (26-40-GHz) two-resonators filter example with a midband frequency of f0= 37 GHz is about 70 dB, whereas its planar circuit single-metal-insert counterpart reaches only about 34 dB. A Ku-band (12- 18-GHz) filter prototype with three metal-etched screens yields a measured passband insertion loss of 0.8 dB at about f0= 17 GHz and a measured attenuation in upper stopband of about 50 dB up to 25 GHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Convergence of Local and Average Values in Three-Dimensional Moment-Method Solutions (Short Papers)

    Publication Year: 1985 , Page(s): 649 - 654
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB)  

    Block models using 8, 64, 216, 512, 1000, 1728, and 2744 cubical cells were used to evaluate the load and average specific absorption rate (SAR) for a dielectric cube irradiated by an EM plane wave. All seven models were used in examples for 0.5-cm and 2.5-cm saline cubes at 400 MHz and a 30-cm cube of biological tissue at 27.12 MHz. In each example, the solutions using 8 or 64 cells were similar to that for a sphere rather than a cube. Many cells are needed to approximate the sharp variation of the electric field near corners and edges of a dielectric cube. The heterogeneity of the electric field in an object having corners and edges causes a frequency-independent error (FIE) in addition to the more generally observed frequency-dependent error (FDE) associated with the electrical size of the object. FIE causes the average SAR to converge less rapidly than local values of SAR at locations distant from the corners and edges. An extrapolant is described that corrects for FDE but not FIE in order to estimate the volume average SAR. 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