By Topic

Microwave Theory and Techniques, IEEE Transactions on

Issue 6 • Date Jun. 1975

Filter Results

Displaying Results 1 - 22 of 22
  • [Front cover - Jun. 1975]

    Publication Year: 1975 , Page(s): f1 - f2
    Save to Project icon | Request Permissions | PDF file iconPDF (159 KB)  
    Freely Available from IEEE
  • Comments on "Error in Impedance Measurement When the Signal is Introduced Across the Slotted-Line Probe" [Letters]

    Publication Year: 1975 , Page(s): 536 - 537
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (142 KB)  

    In the above short paper,l an attempt was made to calculate the errors in VSWR and phase caused by detector mismatch in a backwards connected (power into the probe) slotted line. The short paper is wrong. There will be no first-order errors as predicted theoretically in the referenced short paper. The errors encountered in measuring nonlinear devices (diodes) are more complex than those encountered in measuring linear devices. It is very important that the harmonics generated by tbe diode being measured be absorbpd in a matched load and kept out of the detector (especially for high-VSWR diodes). A low-pass filter is commonly used in front of the detector, but (unless it is padded) this filter reflects the harmonic power back into the diode. When the diode being measured does not see a match at the harmonic frequencies, then the harmonic mismatch will interact with the diode to make more efficient or less efficient the conversion to harmonics, depending on the phase relationship between diode and harmonic mismatch. The variable conversion to harmonics will change the impedance of the diode being measured (at the fundamental frequency) as the phase between diode and harmonic mismatch (unpadded low-pass filter) is varied. Therefore, when using a backwards-connected slotted line, it is important to have in front of the detector a low-pass filter that is padded or otherwise matched at the harmonic frequencies as seen from the diode. It is not important for the detector to be matched at the fundamental frequency in a backwards-connected slotted line, as proven in the following discussion. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Correction to "A Class of Waveguide Filters for Over-Moded Applications" (Letters)

    Publication Year: 1975 , Page(s): 537
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (50 KB)  

    In the above paper, two typographical errors should be noted. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contributors, Jun. 1975

    Publication Year: 1975 , Page(s): 538 - 540
    Save to Project icon | Request Permissions | PDF file iconPDF (555 KB)  
    Freely Available from IEEE
  • [Back cover]

    Publication Year: 1975 , Page(s): b1 - b2
    Save to Project icon | Request Permissions | PDF file iconPDF (98 KB)  
    Freely Available from IEEE
  • Equivalent Circuit of the Schottky-Barrier Field-Effect Transistor at Microwave Frequencies (Short Papers)

    Publication Year: 1975 , Page(s): 499 - 501
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (344 KB)  

    Johnson's high-frequency representation theory for MOSFET's, experimentally confirmed by Hopkins up to 1 GHz, is extended in this short paper for SBFET's and is found to substantially agree with data for 1-mu m- and 1/2-mu m-gate GaAs SBFET's up to 12 GHz. Regenerative-feedback conductance not accounted for by conventional models is seen to be present in SBFET's at microwave frequencies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • X-Band Microstrip-Inserted Puck Circulator Using Arc-Plasma-Sprayed Ferrite (Short Papers)

    Publication Year: 1975 , Page(s): 504 - 506
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    Experimental circulators using ferrite pucks which have been sprayed into cavities in dielectric substrates by an arc-plasma spray (APS) process are described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A New Class of Nonreciprocal Components Using Slot Line (Short Papers)

    Publication Year: 1975 , Page(s): 511 - 516
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    The authors present an experimental and theoretical study of edge modes in a ferrite-loaded slot line. Nonreciprocal properties are obtained over a broad frequency band. Added microstrip lines provide suitable transitions. A theory based on magnetic boundary conditions shows good agreement with the experimental results and allows a comparison with stripline devices described by Hines. In particular, the characteristics of the slot-line isolators are satisfactorily explained by this theory. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Edge-Guided-Wave Circulator (Short Papers)

    Publication Year: 1975 , Page(s): 516 - 519
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    A complete study is presented on "edge-guided-wave" circulators (EGC). The fundamental physical principles which underlie EGC's operation are established and exploited to construct a broad-band circulator in the 8-12-GHz band. The performance data are compared to those of a "continuous tracking" circulator (CTC) and a traditional Y-junction circulator. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • High Data-Rate Solid-State Millimeter-Wave Transmitter Module

    Publication Year: 1975 , Page(s): 470 - 477
    Cited by:  Papers (7)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1144 KB)  

    This paper describes a solid-state millimeter-wave transmitter module consisting of an IMPATT oscillator, p-i-n quadri-phase modulator, and a three-stage IMPATT amplifier. The module has been operated up to 4-Gbits/s modulation rate with 500-mW output power in the 60-GHz range. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Frequency Multiplication By A P-I-N Diode When Driven Into Avalanche Breakdown

    Publication Year: 1975 , Page(s): 477 - 485
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB)  

    An investigation of frequency multiplication using a step-recovery diode (SRD) driven into avalanche breakdown is presented. This mode of operation, which is called the "breakdown mode," consists of a reverse-biased p-n junction, SRD, or IMPATT diode driven into reverse breakdown by an ac signal source. As the diode voltage passes from reverse bias to reverse breakdown and avalanche, the state of the diode switches quickfy from a depletion-layer capacitance to an avalanche inductance; hence the production of strong harmonics. A theoretical analysis and experimental investigation of a coaxial/waveguide 2-6-GHz frequency multiplier using HP5082-0320 step-recovery diodes, [Rs = 0.75 Omega, Cd(-6v) = 1.0 pF] shows that the breakdown-mode frequency multiplier has a higher conversion efficiency than the conventional "charge-storage" multipuer. A measured conversion efficiency of 73 percent was achieved while the same circuit configuration produced 52 percent for the same diode used as a charge-storage multiplier under optimum forward-drive and tuning conditions. Also the theory developed in this paper indicates a maximum possible conversion efficiency of 80 percent for the breakdown-mode multiplier, which corresponds closely with the measured results, and a maximum theoretical efficiency for a forward driven diode of 64 percent. The performance of an FM microwave system was monitored using the breakdown multiplier as a LO in which a baseband SNR of 59 dB was recorded. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Millimeter-Wave Reflection-Beam Isolator (Short Papers)

    Publication Year: 1975 , Page(s): 506 - 508
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    A new and simple type of millimeter-wave isolator using a solid-state magnetoplasma in a reflection-beam system is described. Some data are presented showing performance at 94 GHz. Practical considerations indicate that performance should be much closer to ideal at higher frequencies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microwave Measurement of the Temperature Coefficient of Permittivity for Sapphire and Alumina (Short Papers)

    Publication Year: 1975 , Page(s): 526 - 529
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    Measurements of the temperature coefficients of permittivity and of thermal expansion, for the important MIC substrate materials alumina and sapphire, are reported. The results are presented and in the case of sapphire include figures for the two main crystal orientations. An interesting correlation exists between our results for alumina substrates, and those for sapphire substrates in which the optical axis is perpendicular to the plane of the slice. The temperature stability of resonators on sapphire and alumina is discussed and experimental data are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurements of Intercavity Couplings (Short Papers)

    Publication Year: 1975 , Page(s): 519 - 522
    Cited by:  Papers (39)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    This short paper describes the determination of couplings within a system of coupled cavities by measuring frequencies at which the phase of the input reflection coefficient is either 0° or 180°. A high degree of accuracy may be achieved and corrections can be made for finite cavity Q. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Broad-Band Varactor-Tuned Impatt-Diode Oscillator (Short Papers)

    Publication Year: 1975 , Page(s): 501 - 504
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB)  

    A varactor-tuned IMPATT-diode oscillator with a continuous and monotonic tuning bandwidth of 27 percent and a potential tuning range in excess of 40 percent is described. The results of a computer program which optimizes the tuning bandwidth of the equivalent circuit of the voltage-controlled oscillator (VCO) are presented. The VCO consists of two varactors located symmetrically on each side of an IMPATT diode all mounted in a ridged waveguide with two matched outputs into 50-Omega coaxial. Experimental results on bandwidth, power output, frequency linearity, and FM noise are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerical Analysis of Eigenvalue Solution of Disk Resonator (Short Papers)

    Publication Year: 1975 , Page(s): 508 - 511
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (440 KB)  

    A formulation is proposed to calculate the frequencies of the eigenmodes for a resonator with a thin conductor disk placed in the median plane between two infinite parallel conductor plates. The numerical analysis is carried out for the E- and EH-modes, and these eigenvalues are calculated as the function of the ratio of the disk radius to the distance between the disk and one of the infinite conductor plates. It is shown that at a ratio greater than a certain value the exact eigenvalue is smaller than the one predicted by applying the conventional method for two-dimensional bifurcation of rectangular waveguide, but the latter becomes closer to the exact one with increasing ratio. The availability of our exact eigenvalues is demonstrated in determining experimentally the dielectric constant of Teflon plate specimen by applying those values. Then the constancy of the measured dielectric constant is confirmed irrespective of the modes and the ratios. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of 2450-Mhz Radiation on the Rabbit Eye

    Publication Year: 1975 , Page(s): 492 - 498
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (776 KB)  

    The cataractogenic effects of near-zone 2450-MHz radiation in rabbits are presented. The power deposition pattern inside the eyes and head of rabbits has been determined using a thermocouple technique. It was found that a peak absorption of 0.92 W/kg occurred between the lens of the eye and the retina for each milliwatt/square centimeter incident. Time and power-density studies indicated a cataractogenic threshold of a 150-mW/cm2 incident, or 138-W/kg peak absorption behind the lens for 100 min. The threshold time decreased with increasing power density. Agreement between in vivo intraocular temperature measurements and finite-element computer predictions reinforces the suggestion of a thermal mechanism for microwave-induced lens opacities. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fiber and Diffused Waveguide Structures for Distributed-Feedback Lasers (Short Papers)

    Publication Year: 1975 , Page(s): 532 - 536
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (360 KB)  

    Optimum threshold conditions for oscillations of transversely bounded distributed-feedback (DFB) lasers are derived and discussed for the case of a fiber guide and diffused guide. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electromagnetic Power Absorption in Anisotropic Tissue Media (Short Papers)

    Publication Year: 1975 , Page(s): 529 - 532
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    Strong dielectric-constant anisotropy exists in muscle tissue at the lower microwave frequencies. Based on a model derived from tissue measurements, an analysis is carried out for single and multiple tissue layers. Calculated effects of tissue anisotropy on microwave fields and power absorption in the tissues are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Loss Considerations for Microstrip Resonators (Short Papers)

    Publication Year: 1975 , Page(s): 522 - 526
    Cited by:  Papers (31)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (480 KB)  

    The influence of radiation losses on the Q of microstrip resonators is shown for a variety of frequencies, characteristic impedances, substrate materials, and thicknesses. Radiation becomes a dominant factor at higher frequencies, especially for low-impedance lines and thick substrates with a low dielectric constant. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Design of Coupled Microstrip Lines

    Publication Year: 1975 , Page(s): 486 - 492
    Cited by:  Papers (43)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (680 KB)  

    Although graphical results and formulas are available for the design of microstrip couplers, the design procedure is hampered because even- and odd-mode impedances are always expressed in terms of the physical geometry. In practice the designer obtains these impedances and then requires to know the geometry given by them. A new design procedure for coupled parallel microstrip lines is therefore presented. The technique enables the geometry of the coupled lines to be obtained directly from the required even- and odd-mode impedances and uses single microstrip-line geometry as an intermediate step. The results are presented in graphical form using only two universal families of curves. Results are also presented in the form of simple formulas for design programs and also comparisons with practical results are made. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance of Dual-Gate GaAs MESFET's as Gain-Controlled Low-Noise Amplifiers and High-Speed Modulators

    Publication Year: 1975 , Page(s): 461 - 469
    Cited by:  Papers (58)  |  Patents (109)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1600 KB)  

    This paper describes the microwave performance of GaAs FET's with two 1-mu m Schottky-barrier gates (dual-gate MESFET). At 10 GHz the MESFET, with an inductive second-gate termination, exhibits an 18-dB gain with --26-dB reverse isolation. Variation of the second-gate potential yields a 44-dB gain-modulation range. The minimum noise figure is 4.0 dB with 12-dB associated gain at 10 GHz. Pulse modulation of an RF carrier with a 65-ps fall ad a 100-ps rise time is demonstrated. The dual-gate MESFET with high gain and low noise figure is especially suited for receiver amplifiers with automatic gain control (AGC) as an option. The MESFET is equally attractive for subnanosecond pulsed-amplitude modulation (PAM), phase-shift-keyed (PSK), and frequency-shift-keyed (FSK) carrier modulation. 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