Pub Date : 1962-09-01DOI: 10.1109/JRPROC.1962.288173
R. Schoenfeld
Criteria for bandwidth limits for neutralized input capacity amplifiers are developed. The behavior of different neutralization schemes is analyzed in terms of the root locus of the system gain function. This technique permits quantitative design and evaluation of the different circuits that have been used. It makes it possible to judge the effectiveness of new approaches to the problem. It is shown that second-order amplifiers may achieve inherently faster response than amplifiers with a single time constant. Using a critically damped criterion, the maximum bandwidth of the second-order amplifier is equal to the cube root of the product of the input circuit bandwidth times the square of the amplifier bandwidth with the input circuit removed. A single time constant amplifier has a maximum bandwidth equal to the square root of the product of the input circuit bandwidth times that of the amplifier alone. It is shown also that one may have to choose between speed of response and excess noise. The noise figure of these systems may increase markedly with bandwidth and increases to a lesser degree with the system complexity.
{"title":"Bandwidth Limits for Neutralized Input Capacity Amplifiers","authors":"R. Schoenfeld","doi":"10.1109/JRPROC.1962.288173","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288173","url":null,"abstract":"Criteria for bandwidth limits for neutralized input capacity amplifiers are developed. The behavior of different neutralization schemes is analyzed in terms of the root locus of the system gain function. This technique permits quantitative design and evaluation of the different circuits that have been used. It makes it possible to judge the effectiveness of new approaches to the problem. It is shown that second-order amplifiers may achieve inherently faster response than amplifiers with a single time constant. Using a critically damped criterion, the maximum bandwidth of the second-order amplifier is equal to the cube root of the product of the input circuit bandwidth times the square of the amplifier bandwidth with the input circuit removed. A single time constant amplifier has a maximum bandwidth equal to the square root of the product of the input circuit bandwidth times that of the amplifier alone. It is shown also that one may have to choose between speed of response and excess noise. The noise figure of these systems may increase markedly with bandwidth and increases to a lesser degree with the system complexity.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"4 1","pages":"1942-1950"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82394341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-09-01DOI: 10.1109/JRPROC.1962.288172
J. Moore, J. Gebhart
The need for a wide-band preamplifier to measure bioelectric potentials from a source with high internal resistance and shunt capacitance has stimulated the development of instruments which should be generally useful. Consideration is given to the simultaneous attainment of such factors as low grid current, linearity, low drift, and improved dynamic response by compensation for input capacitance. An analysis of a simplified circuit is augmented by the use of an analog computer to simulate the system for a preamplifier having either a first- or second-order response. Some examples of circuits suitable for bioelectric measurements are described. It has been possible to chopper-stabilize such preamplifiers against drift without significant degradation of their high input impedance characteristics.
{"title":"Stabilized Wide-Band Potentiometric Preamplifiers","authors":"J. Moore, J. Gebhart","doi":"10.1109/JRPROC.1962.288172","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288172","url":null,"abstract":"The need for a wide-band preamplifier to measure bioelectric potentials from a source with high internal resistance and shunt capacitance has stimulated the development of instruments which should be generally useful. Consideration is given to the simultaneous attainment of such factors as low grid current, linearity, low drift, and improved dynamic response by compensation for input capacitance. An analysis of a simplified circuit is augmented by the use of an analog computer to simulate the system for a preamplifier having either a first- or second-order response. Some examples of circuits suitable for bioelectric measurements are described. It has been possible to chopper-stabilize such preamplifiers against drift without significant degradation of their high input impedance characteristics.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"25 1","pages":"1928-1941"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73718739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-09-01DOI: 10.1109/JRPROC.1962.288169
James P. Gordon
The information capacity of various communications systems is considered. Quantum effects are taken fully into account. The entropy of an electromagnetic wave having the quantum statistical properties of white noise in a single transmission mode is found, and from it the information efficiency of various possible systems may be derived. The receiving systems considered include amplifiers, heterodyne and homodyne converters and quantum counters. In the limit of high signal or noise power (compared to hνB, where h is Planck's constant and ν and B are, respectively, the center frequency and bandwidth of the channel) the information efficiency of an amplifier can approach unity. In the limit of low powers the amplifier becomes inefficient, while the efficiency of the quantum counter can approach unity. The amount of information that can be incorporated in a wave drops off rather rapidly when the power drops below hνB.
{"title":"Quantum Effects in Communications Systems","authors":"James P. Gordon","doi":"10.1109/JRPROC.1962.288169","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288169","url":null,"abstract":"The information capacity of various communications systems is considered. Quantum effects are taken fully into account. The entropy of an electromagnetic wave having the quantum statistical properties of white noise in a single transmission mode is found, and from it the information efficiency of various possible systems may be derived. The receiving systems considered include amplifiers, heterodyne and homodyne converters and quantum counters. In the limit of high signal or noise power (compared to hνB, where h is Planck's constant and ν and B are, respectively, the center frequency and bandwidth of the channel) the information efficiency of an amplifier can approach unity. In the limit of low powers the amplifier becomes inefficient, while the efficiency of the quantum counter can approach unity. The amount of information that can be incorporated in a wave drops off rather rapidly when the power drops below hνB.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"27 1","pages":"1898-1908"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78878236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-09-01DOI: 10.1109/JRPROC.1962.288174
H. Ko
The response of an elliptically polarized antenna to a quasi-monochromatic, partially polarized radio wave is treated from the standpoint of coherence theory. A general formula is derived for the available power at the terminals of a receiving antenna in terms of appropriately chosen coherency matrices for the antenna and the incident wave. It is shown that the result is formally identical with the basic interference law of partially coherent, quasi-monochromatic wave fields. Conditions for the maximum available power are discussed, and a geometrical interpretation of the result is given. The coherency matrix for the antenna is determined uniquely in terms of the transmitting properties of the antenna. It is shown that the coherency matrix formalism for the interaction of an antenna with an incident wave fits very well with those used in the modern theory of optics and quantum mechanics. A new definition for the antenna effective aperture using the coherency matrix is suggested, which takes into account the polarization property of the antenna.
{"title":"On the Reception of Quasi-Monochromatic, Partially Polarized Radio Waves","authors":"H. Ko","doi":"10.1109/JRPROC.1962.288174","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288174","url":null,"abstract":"The response of an elliptically polarized antenna to a quasi-monochromatic, partially polarized radio wave is treated from the standpoint of coherence theory. A general formula is derived for the available power at the terminals of a receiving antenna in terms of appropriately chosen coherency matrices for the antenna and the incident wave. It is shown that the result is formally identical with the basic interference law of partially coherent, quasi-monochromatic wave fields. Conditions for the maximum available power are discussed, and a geometrical interpretation of the result is given. The coherency matrix for the antenna is determined uniquely in terms of the transmitting properties of the antenna. It is shown that the coherency matrix formalism for the interaction of an antenna with an incident wave fits very well with those used in the modern theory of optics and quantum mechanics. A new definition for the antenna effective aperture using the coherency matrix is suggested, which takes into account the polarization property of the antenna.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"49 1","pages":"1950-1957"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77550620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-08-01DOI: 10.1109/JRPROC.1962.288219
J. Fontana, R. Pantell
The generation of radiation by miing optical maser signals is one possible method for closing the gap between microwaves and infrared. The conversion efficiency attainable with different types of nonlinear media is considered. It is shown that lossless nonlinear media, such as dielectrics, have very low conversion efficiency properties, regardless of the way they are used. Nonlinear resistive media, on the other hand, have efficiencies up to 25 per cent, independently of the frequency conversion ratio. Consequently, in order to generate wavelengths in the nillimeter range by mixing optical maser outputs, the materials used should involve nonlinear dissipative processes.
{"title":"Theoretical Considerations on Millimeter Wave Generation by Optical Frequency Mixing","authors":"J. Fontana, R. Pantell","doi":"10.1109/JRPROC.1962.288219","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288219","url":null,"abstract":"The generation of radiation by miing optical maser signals is one possible method for closing the gap between microwaves and infrared. The conversion efficiency attainable with different types of nonlinear media is considered. It is shown that lossless nonlinear media, such as dielectrics, have very low conversion efficiency properties, regardless of the way they are used. Nonlinear resistive media, on the other hand, have efficiencies up to 25 per cent, independently of the frequency conversion ratio. Consequently, in order to generate wavelengths in the nillimeter range by mixing optical maser outputs, the materials used should involve nonlinear dissipative processes.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"30 1","pages":"1796-1800"},"PeriodicalIF":0.0,"publicationDate":"1962-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82405151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-08-01DOI: 10.1109/JRPROC.1962.288222
R. Bechmann, A. Ballato, T. Lukaszek
The first-, second-, and third-order temperature coefficients of the elastic stiffnesses and compliances of alpha-quartz have been derived from thickness mode resonances of double-rotated quartz plates employing Christoffel's theory of wave propagation. The temperature dependence of all possible thickness modes can be calculated from the values of the elastic stiffnesses and their temperature coefficients as derived during this investigation. A curve showing the locus of the first-order zero temperature coefficient of frequency of thickness-shear modes has been calculated and compared with experiments. The second- and third-order temperature coefficients of frequency of the first-order zero quartz cuts are given. Applications to AT, BT, CT, and DT cuts are made by comparing the calculated with the experimental values which characterize the temperature behavior of frequencies and new useful piezoelectric cuts of quartz are indicated.
{"title":"Higher-Order Temperature Coefficients of the Elastic Stiffinesses and Compliances of Alpha-Quartz","authors":"R. Bechmann, A. Ballato, T. Lukaszek","doi":"10.1109/JRPROC.1962.288222","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288222","url":null,"abstract":"The first-, second-, and third-order temperature coefficients of the elastic stiffnesses and compliances of alpha-quartz have been derived from thickness mode resonances of double-rotated quartz plates employing Christoffel's theory of wave propagation. The temperature dependence of all possible thickness modes can be calculated from the values of the elastic stiffnesses and their temperature coefficients as derived during this investigation. A curve showing the locus of the first-order zero temperature coefficient of frequency of thickness-shear modes has been calculated and compared with experiments. The second- and third-order temperature coefficients of frequency of the first-order zero quartz cuts are given. Applications to AT, BT, CT, and DT cuts are made by comparing the calculated with the experimental values which characterize the temperature behavior of frequencies and new useful piezoelectric cuts of quartz are indicated.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"51 1","pages":"1812-1822"},"PeriodicalIF":0.0,"publicationDate":"1962-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76535357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-08-01DOI: 10.1109/JRPROC.1962.288220
R. Frost, O. T. Purl, H. R. Johnson
A new method has been employed for the design of solid-beam electron guns of high perveance and area convergence. This has resulted in designs with perveance 2.2×10-6 a/v3/2 and convergence ratio 300; and perveance 5×10-6 a/V3/2 and area convergence 6. Using conventional methods, a design with perveance 0.1×10-6a/v3/2 and area convergence ratio 1000 has been obtained. Each of these guns has yielded over 95 per cent transmission through a drift tube, in most cases with less than 1.5 times theoretical Brillouin focusing magnetic field. The design method consists of 1) paper design following earlier workers; 2) construction of a model using the design cathode and anode, but with the focus electrode replaced by a series of annular disk electrodes; 3) measurement, in pulsed bell-jar beam tester, of the beam leaving this gun, by means of a pinhole aperture followed by a split collector, yielding data on current density and trajectory angle as a function of radius and axial position; 4) modifications of annular disk potentials and cathode surface shape to improve beam quality; 5) electrolytic tank determination of the shape of a single electrode to replace the annular disks; and 6) test of the final design in a sealed-off, shielded-cathode, pulsed beam tester in which the beam flows through a drift tube in a uniform magnetic field. These methods are relatively exact and rapid. Drawings are presented for some specific designs.
{"title":"Electron Guns for Forming Solid Beams of High Perveance and High Convergence","authors":"R. Frost, O. T. Purl, H. R. Johnson","doi":"10.1109/JRPROC.1962.288220","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288220","url":null,"abstract":"A new method has been employed for the design of solid-beam electron guns of high perveance and area convergence. This has resulted in designs with perveance 2.2×10-6 a/v3/2 and convergence ratio 300; and perveance 5×10-6 a/V3/2 and area convergence 6. Using conventional methods, a design with perveance 0.1×10-6a/v3/2 and area convergence ratio 1000 has been obtained. Each of these guns has yielded over 95 per cent transmission through a drift tube, in most cases with less than 1.5 times theoretical Brillouin focusing magnetic field. The design method consists of 1) paper design following earlier workers; 2) construction of a model using the design cathode and anode, but with the focus electrode replaced by a series of annular disk electrodes; 3) measurement, in pulsed bell-jar beam tester, of the beam leaving this gun, by means of a pinhole aperture followed by a split collector, yielding data on current density and trajectory angle as a function of radius and axial position; 4) modifications of annular disk potentials and cathode surface shape to improve beam quality; 5) electrolytic tank determination of the shape of a single electrode to replace the annular disks; and 6) test of the final design in a sealed-off, shielded-cathode, pulsed beam tester in which the beam flows through a drift tube in a uniform magnetic field. These methods are relatively exact and rapid. Drawings are presented for some specific designs.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"10 1","pages":"1800-1807"},"PeriodicalIF":0.0,"publicationDate":"1962-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81747698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-08-01DOI: 10.1109/JRPROC.1962.288217
A. Nussbaum
The purpose of this paper is to present the principles involved in calculating the energy band structures of semiconductors. These calculations can be simplified by the use of group theory, which is a branch of analysis that permits expressing the symmetry properties of crystals in a quantitative manner. Some of the simpler concepts of group theory are explained and then applied to band structure determinations.
{"title":"Group Theory and the Energy Band Structure of Semiconductors","authors":"A. Nussbaum","doi":"10.1109/JRPROC.1962.288217","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288217","url":null,"abstract":"The purpose of this paper is to present the principles involved in calculating the energy band structures of semiconductors. These calculations can be simplified by the use of group theory, which is a branch of analysis that permits expressing the symmetry properties of crystals in a quantitative manner. Some of the simpler concepts of group theory are explained and then applied to band structure determinations.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"63 1","pages":"1762-1781"},"PeriodicalIF":0.0,"publicationDate":"1962-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72766130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-08-01DOI: 10.1109/JRPROC.1962.288218
M. Lampert
The basic principles of one- and two-carrier, volume-controlled injection currents are reviewed. One-carrier injected currents are necessarily space-charge-limited and are strongly affected by the presence of traps which usually capture and immobilize most of the injected carriers. The trapped carriers are in an effective thermal equilibrium with the free injected carriers. The concepts of "shallow" and "deep" traps are defined and their effects on injected currents studied. It is shown that the presence of "deep" traps leads to a very steep rise of current with voltage, resembling a breakdown curve, at an appropriate voltage. Under double injection, that is, the simultaneous injection into the insulator of electrons from a cathode and holes from an anode, space-charge limitations are at least partially overcome but recombination of injected carriers presents a new limitation on the current flow. In any insulator at sufficiently high injection levels both recombination and space charge contribute to limitation of the current, leading to a dependence of current on the cube of the voltage, for monomolecular recombination processes. For double injection into a semiconductor, the presence of thermally generated free carriers leads to charge neutrality (the so-called ohmic relaxation process) and recombination alone limits the current. In a semiconductor long compared to a diffusion length this leads to a dependence of current on the square of the voltage.
{"title":"Injection Currents in Insulators","authors":"M. Lampert","doi":"10.1109/JRPROC.1962.288218","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288218","url":null,"abstract":"The basic principles of one- and two-carrier, volume-controlled injection currents are reviewed. One-carrier injected currents are necessarily space-charge-limited and are strongly affected by the presence of traps which usually capture and immobilize most of the injected carriers. The trapped carriers are in an effective thermal equilibrium with the free injected carriers. The concepts of \"shallow\" and \"deep\" traps are defined and their effects on injected currents studied. It is shown that the presence of \"deep\" traps leads to a very steep rise of current with voltage, resembling a breakdown curve, at an appropriate voltage. Under double injection, that is, the simultaneous injection into the insulator of electrons from a cathode and holes from an anode, space-charge limitations are at least partially overcome but recombination of injected carriers presents a new limitation on the current flow. In any insulator at sufficiently high injection levels both recombination and space charge contribute to limitation of the current, leading to a dependence of current on the cube of the voltage, for monomolecular recombination processes. For double injection into a semiconductor, the presence of thermally generated free carriers leads to charge neutrality (the so-called ohmic relaxation process) and recombination alone limits the current. In a semiconductor long compared to a diffusion length this leads to a dependence of current on the square of the voltage.","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"281 1","pages":"1781-1796"},"PeriodicalIF":0.0,"publicationDate":"1962-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76799426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1962-07-13DOI: 10.1109/JRPROC.1962.288329
L. Berkner
{"title":"Geoscience and Geoengineering","authors":"L. Berkner","doi":"10.1109/JRPROC.1962.288329","DOIUrl":"https://doi.org/10.1109/JRPROC.1962.288329","url":null,"abstract":"","PeriodicalId":20574,"journal":{"name":"Proceedings of the IRE","volume":"84 1","pages":"2180-2182"},"PeriodicalIF":0.0,"publicationDate":"1962-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76037210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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