Scheduled System Maintenance:
On May 6th, single article purchases and IEEE account management will be unavailable from 8:00 AM - 12:00 PM ET (12:00 - 16:00 UTC). We apologize for the inconvenience.
By Topic

Proceedings of the IEEE

Issue 1 • Date Jan. 1968

Filter Results

Displaying Results 1 - 25 of 74
  • [Front cover and table of contents]

    Publication Year: 1968 , Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (353 KB)  
    Freely Available from IEEE
  • Scanning the issue

    Publication Year: 1968 , Page(s): 1
    Save to Project icon | Request Permissions | PDF file iconPDF (144 KB)  
    Freely Available from IEEE
  • Distortion and crosstalk of linearly filtered, angle-modulated signals

    Publication Year: 1968 , Page(s): 2 - 13
    Cited by:  Papers (41)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1039 KB)  

    An important problem in the theory and practice of receiving angle-modulated signals is the design of the filtering elements which must be employed. It has long been known that filtering introduces distortion and crosstalk into the signal. However, the computation of these effects is difficult. The methods customarily used employ approximations of one kind or another, and the equations used do not apply to all cases of practical interest. Here formulas are presented which enlarge somewhat the domain of cases amenable to calculation. In this analysis, an angle-modulated signal having an arbitrary phase function is applied to a general linear filter, and the phase of the output is expanded in a series having the linearly filtered input as the leading term. The expansion is then specialized to the case of a narrowband signal applied to a narrow, symmetrical, bandpass filter. A spectral analysis is performed by assuming a Gaussian input phase and examining terms through fifth order in the output phase expansion. This leads to the main results of the paper, namely expressions for the leading terms in the output spectrum. It is argued that these terms represent the principal contribution in the case where the distortion is small. To demonstrate their application to a practical problem, the formulas are used to calculate the distortion and crosstalk produced when an FM signal, having a flat baseband spectrum, is passed through a single-pole filter. This example is of some current interest because such a filter has been employed in the forward path of a feedback FM receiver used for satellite communication. A number of cases are considered, and the results of the computations are plotted. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Small-signal behavior of nonlinear lumped networks

    Publication Year: 1968 , Page(s): 14 - 22
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (753 KB)  

    This paper develops two theorems concerning the small-signal behavior of nonlinear time-varying networks whose state equations are of the form x·= f(x, u, t). The conclusions of the theorems are supported by experiments. The input is of the form U(t) + u(t), where the bias U(t) is allowed to be time-varying (typically, slowly varying) and u(t) is the small signal. The bias induces a moving operation point X(t). Given some simple assumptions concerning the linearized small-signal equivalent circuit it is shown that provided u(t) is sufficiently small on [0, ∞), the state trajectory about the operating point is bounded on [0, ∞) and tends to zero as u → 0. The method of proof also shows that this result applies to some distributed circuits. The second theorem shows that the push-pull connection reduces the distortion due to the nonlinearities of both resistors and energy storing elements. The third part of the paper describes numerical experiments that support the conclusions of the theory and a design procedure for nonlinear networks to be operated in the small-signal mode. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Standing spin waves in ferromagnetic thin films

    Publication Year: 1968 , Page(s): 23 - 31
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (733 KB)  

    A theory of spin wave resonance in ferromagnetic thin films is discussed in a manner that permits a computation of the real and imaginary parts of the circularly polarized RF fields as well as the power absorption spectrum. The case of the dc field intensity applied normal to the surface of the film is considered, and the saturation magnetization is taken as constant throughout the body of the film. Variations in dc fields near the surfaces are treated in the boundary conditions for the RF magnetization by considering the unsymmetrical nature of the exchange interaction at the surfaces. The boundary conditions are characterized by a constant for each surface that controls the degree of surface pinning in the RF magnetization. Damping is included in the formulation by means of a phenomenological constant in the spin wave equation and by simulaneous solution of this equation with Maxwell's equations for a conductor. The results of a computer program are presented showing the roles of the various parameters in determining the power absorption spectrum and RF fields. A comparison with experimental spectra is made, and an anomalous resonance at field intensities higher than that for the principal resonance is predicted. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Thermal annealing of proton-irradiated silicon solar cells

    Publication Year: 1968 , Page(s): 31 - 37
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (691 KB)  

    Solar cells made from 1.5- and 10-Ωċcm p-type silicon, with silver-titanium evaporated electrodes, were irradiated by 4.6-MeV protons at room temperature to fluences ranging from 1 × 1010to 1 × 1012protons/cm2. The photovoltaic current-voltage characteristics, the photovoltaic spectral response, and the minority carrier diffusion length were studied as the solar cells were annealed isochronally to temperatures up to 600°C. The proton radiation damage annealed in two stages, the first occurring between 50° and 150°C, and the second between 350° and 450°C. The removal of proton damage in this manner differs markedly from the annealing reported for 1-MeV electron damage, where practically no recovery of the photovoltaic properties is observed below 350°C. At any selected annealing temperature, the 10-Ω ċ cm cells were observed to recover to a slightly greater degree than the 1.5-Ω ċ cm type. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Infrared heterodyne detection

    Publication Year: 1968 , Page(s): 37 - 46
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2140 KB)  

    Heterodyne experiments have been performed in the middle infrared region of the electromagnetic spectrum using the CO2laser as a radiation source. Theoretically optimum operation has been achieved at kHz heterodyne frequencies using photoconductive Ge:Cu detectors operated at 4°K, and at kHz and MHz frequencies using Pb1-xSnxSe photovoltaic detectors at 77°K. In accordance with the theory, the minimum detectable power observed is a factor of 2/η greater than the theoretically perfect quantum counter, hvΔf. The coefficient 2/η varies from 5 to 25 for the detectors investigated in this study. A comparison is made between photoconductive and photodiode detectors for heterodyne use in the infrared, and it is concluded that both are useful. Heterodyne detection at 10.6 µm is expected to be useful for communications applications, infrared radar, and heterodyne spectroscopy. It has particular significance because of the high radiation power available from the CO2laser, and because of the 8 to 14 µm atmospheric window. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmission line pulse transformers—Theory and applications

    Publication Year: 1968 , Page(s): 47 - 62
    Cited by:  Papers (14)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3274 KB)  

    The advent of fast rise-time pulse techniques and their increasing importance brought on by high-speed microminiature circuits and the computer industry has resulted in an increased demand for pulse transformers of various types. The basic idea of constructing transmission line type transformers has been known and used for a number of years. However, such devices have not gained widespread usage, partly because their existence is not well known, but largely because of a lack of basic understanding of their operating principles in terms of elementary fundamentals as well as their capabilities and limitations. The purpose of this paper is twofold. One aim is to develop in step-by-step fashion the basic ideas of transmission line transformers from ordinary transmission line theory. The subject will be approached from the point of view of pulse response rather than ac excitation as is usually the case. Both impedance transformers and balanced-to-unbalanced (balun) transformers, including inverters, will be considered with physical insights into their operation. Several fundamental concepts will be developed and explored in detail (without mathematics), since they have a strong bearing on practical applications. The second purpose is to present new information and pulse measurements which will be useful in the design and applications of such devices, showing their capabilities and hitherto unexplored limitations, as derived from the fundamental concepts. Thus, this paper is partly supplementary to other published work and partly new work with the goal of providing a convenient fundamental understanding of these devices and their inherent potential and shortcomings. Although the intention is not to give a detailed design procedure, some approximate calculations and discussion of significant design criteria are included. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Maximally flat approximation techniques

    Publication Year: 1968 , Page(s): 65 - 66
    Cited by:  Papers (3)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (217 KB)  

    Design procedures are developed for the Taylor approximation of prescribed network characteristics in the neighborhood of an arbitrary frequency. The desired characteristic may represent either the phase, or the loss, or both. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Uniform distributed amplifier analysis with fast and slow waves

    Publication Year: 1968 , Page(s): 66 - 67
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (198 KB)  

    A uniform distributed amplifier with passive and active, but no inductive, coupling can be represented in most practical cases with an exact distributed equivalent circuit consisting of simple fast and slow mode transmission lines having equal terminators. With ohmic terminators, reflected backward waves always exist (f ≠ ∞). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rectifying contacts under evaporated CdS

    Publication Year: 1968 , Page(s): 68
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (246 KB)  

    Previously, formation of blocking contacts to evaporated CdS with high work function metals has depended on the order of deposition. A method is described whereby blocking contact, rather than the usual ohmic contact, results for CdS deposited on metal. Comparison is favorable with the best diodes obtained by first depositing CdS. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Scintillation reduction of a focused laser beam in a turbulent wind tunnel

    Publication Year: 1968 , Page(s): 69 - 71
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    Theoretical reduction in intensity fluctuations of a focused laser beam propagating through a randomly inhomogeneous medium was qualitatively examined in an experiment in which intensity fluctuations were observed near the focus of the optical system used. A wind tunnel was used to produce the randomly inhomogeneous medium. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the compensation of the nonideal NIC

    Publication Year: 1968 , Page(s): 69
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (97 KB)  

    This letter shows that the criteria for a two-port to be a nonideal NIC in terms of its h parameters should be applied to both orientations of the two-port. Alternatively, a different set of conditions should be used if the two-port is to remain in the same orientation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Immittance transformation chart of a two-port

    Publication Year: 1968 , Page(s): 71 - 72
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB)  

    The immittance transformation chart of a two-port which is used together with the Smith chart to obtain graphically the immittance transformed through a two-port is presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A discussion of an auxiliary matrix

    Publication Year: 1968 , Page(s): 72 - 73
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (190 KB)  

    An auxiliary matrix found in the literature provides a convenient way of evaluating an equidiagonal symmetric matrix such as that encountered in the tree count for a complete simple graph. The generalized form of this matrix is analyzed and several suggested uses are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Intermodulation products generated by a p-i-n diode switch

    Publication Year: 1968 , Page(s): 74 - 75
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (155 KB)  

    Values are reported for the odd-order intermodulation products originating from a p-i-n diode in a UHF SPST switch which is tied to a transmission line carrying two signals. Included are their dependence on power levels, bias, and ambient temperature. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of LSA oscillator noise

    Publication Year: 1968 , Page(s): 75 - 77
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (258 KB)  

    FM noise of the LSA oscillator diode has been investigated in the case where there are density fluctuations between two sub-bands. If the differential mobility is a positive constant below a threshold field and a negative one above it, the power spectrum of the noise may be proportional to that of the density fluctuations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • High-current triode with nonintercepting control electrode

    Publication Year: 1968 , Page(s): 77 - 78
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    A novel triode configuration suitable for high-density electron guns is described in which several insulated posts project through holes in the cathode surface. Results of a pilot high-power, pulsed-voltage experiment are given. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Time-varying circuits for noise measurement

    Publication Year: 1968 , Page(s): 78 - 79
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (226 KB)  

    A time-varying smoothing network with an increasing time constant provides good smoothing and fast initial response. A mathematical model evaluated by digital computer showed that a stepwise time constant increase gives fairly good results even with only two steps. For low-output detectors (e.g., Hall correlators) a continuously varying time constant may be realized by using an FET. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of neglecting Hall term on dispersion relation for hydromagnetic waves

    Publication Year: 1968 , Page(s): 79 - 80
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (218 KB)  

    The Hall term in the generalized Ohm's law is sometimes neglected in analysis of hydromagnetic waves. Some misleading results which arise from neglect of this term are discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cycle-slipping effects on the output signal of a phase-locked demodulator

    Publication Year: 1968 , Page(s): 80 - 81
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB)  

    Experimental results are presented to show the energy distribution of the output signal of a phase-locked loop when used as an FM demodulator. This effect is related to the cycle-slipping phenomena and the modeling of equivalent circuits. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simultaneous oscillations at two frequencies in RLC circuits

    Publication Year: 1968 , Page(s): 82 - 83
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (165 KB)  

    It is shown under which conditions two parallel high-Q resonance RLC circuits connected in series to a voltage-controlled active device, described by an instantaneous characteristic of fifth degree, can oscillate simultaneously at two frequencies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Moments of complex Gaussian processes

    Publication Year: 1968 , Page(s): 83 - 84
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (158 KB)  

    It is shown that the same formula used for calculating the moments of a real multivariate Gaussian process may be used to calculate the moments of a complex Gaussian process. This is a slight generalization of a result of Reed. The method of proof is simple, elegant, and self-contained. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A fast controlled monostable circuit using tunnel diodes

    Publication Year: 1968 , Page(s): 84 - 85
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (334 KB)  

    A circuit is developed for the identification of random events of single and paired pulses. The output pulse length of this "controlled monostable" circuit is proportional to the time interval of the paired pulses and the response to a single pulse is in the monostable mode. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comment on "Energy-transport velocity in electromagnetic waves"

    Publication Year: 1968 , Page(s): 85 - 86
    Save to Project icon | Request Permissions | PDF file iconPDF (199 KB)  
    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The most highly-cited general interest journal in electrical engineering and computer science, the Proceedings is the best way to stay informed on an exemplary range of topics.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
H. Joel Trussell
North Carolina State University