US2806972A - Traveling-wave tube - Google Patents

Traveling-wave tube Download PDF

Info

Publication number
US2806972A
US2806972A US473856A US47385654A US2806972A US 2806972 A US2806972 A US 2806972A US 473856 A US473856 A US 473856A US 47385654 A US47385654 A US 47385654A US 2806972 A US2806972 A US 2806972A
Authority
US
United States
Prior art keywords
wave
ferrite
waveguide
magnetic field
electron stream
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US473856A
Inventor
Sensiper Samuel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hughes Aircraft Co
Original Assignee
Hughes Aircraft Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hughes Aircraft Co filed Critical Hughes Aircraft Co
Priority to US473856A priority Critical patent/US2806972A/en
Application granted granted Critical
Publication of US2806972A publication Critical patent/US2806972A/en
Anticipated expiration legal-status Critical
Application status is Expired - Lifetime legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/16Circuit elements, having distributed capacitance and inductance, structurally associated with the tube and interacting with the discharge
    • H01J23/24Slow-wave structures, e.g. delay systems
    • H01J23/30Damping arrangements associated with slow-wave structures, e.g. for suppression of unwanted oscillations

Description

Sept. 17, 1957 s. sENslPER TRAvELING-WAVE TUBE 3 SheetsFSheet 1 Filed Dec. 8. 1954 Sept. 17, 1957 s. sENslPER 2,806,972

TaAvELING-WAVE TUBE Filed Dec. 8, 1954 3 Sheets-Sheet 2 M M i z ,VH a f a SCPL 17, 1957 s. sENslPER 2,806,972

TRAvELING-WAVE TUBE 3 Sheets-Sheet 3 Filed Deo. 8. 1954 VMM Patented Sept. 17, 1957 TRAVELlNG-WAVE TUBE Samuel Sensiper, Los Angeles, Calif., assignor to Hughes Aircraft Company, Culver City, Calif., a corporation of Delaware Application December 8, 1954, Serial No. 473,856

Claims. (Cl. 315-3.5)

This invention relates to micro-wave tubes and more particularly to a traveling-wave tube incorporating a slow- Wave circuit constituting a periodic waveguide device having unidirectional or selective attenuation characteristics.

ln the conventional traveling-wave tube, a slow-wave structure is generally employed to propagate an electromagnetic signal wave along the path of an electron stream at a velocity to effect interaction between the electromagnetic wave and the electron stream. In that this type of tube provides gain over a broad range of frequencies, it is very difficult to provide an output circuit with an impedance that matches that of the slow-wave structure over this entire range of frequencies. This results in a portion of the energy of the electromagnetic waves appearing at the output circuit being reflected and being propagated back towards the input circuit by the slow-wave structure. When this reflected portion of the output wave arrives at the input circuit, a portion of its energy may again be reflected and propagated along with the electron stream towards the output circuit. This last reflected portion of the electromagnetic wave is progressively amplified along its return path. When this reflected portion is amplified to the extent that it has a magnitude greater than that of the initial Wave appearing at the output circuit, the tube is said to be in self-oscillation. Thus, it is apparent that a traveling-wave tube may self-oscillate at any frequency where the gain is greater than the reflection and propagation losses through the tube.

In accordance with the present invention, a travelingwave tube is provided wherein the tendency to selfoscillate is substantially eliminated whereby gain and power output may be increased. Self-oscillations are eliminated by employing a periodic waveguide device having unidirectional or selective attenuation characteristics for the slow-wave structure of the tube. These unidirectional or selective attenuation characteristics are achieved by utilizing the gyroresonance properties of ferrite materials in conjunction with the magnetic field normally employed for constraining the electron stream. Properties of ferrite materials of the gyroresonance type are described in an article entitled, Ferrites in microwave applications, by J. H. Rowen, which appears on pages 1333-1369 of the Bell System Technical Journal for November 1953, published in New York.

In a first embodiment of the invention, a folded waveguide structure is employed to propagate an electromagnetic wave along a path through the central portion of each waveguide section. In order to provide this structure with unidirectional attenuating characteristics, slabs of ferrite material are disposed within the sections of the waveguide normal to the path of the electron stream, the successive slabs being spaced from the wall of the guide on alternate sides of the electron stream. A single longitudinal magnetic field is then developed to direct the electron stream along the path and to produce gyroresonance within the slabs of ferrite material at frequencies where `the unidirectional attenuating characteristics are desired. The frequency at which gyroresonance with its concomitant maximum attenuation occurs depends on the magneti-c field Within the ferrite material. Thus, the frequencies at which unidirectional attenuation is desired may be staggered throughout the band wherein gain is provided by controlling the magnetic field within the individual ferrite slabs. In that the same magnetomotive force energizes all the ferrite slabs, the magnetic field through any one slab may be determined by its thickness or lessened by a magnetic shunt. In addition, it may be desirable to progressively increase the coupling of the ferrite slabs to the wave being attenuated so as to distribute the heat dissipation uniformly over all of the slabs. This may be accomplished by progressively increasing the spacing between the ferrite slabs and the wall of the waveguide.

An alternative embodiment of the present invention is similar to that described above except that the ferrite slabs are spaced contiguous to the wall of the guide so as to attenuate waves propagated by the guide equally in both directions. This attenuation, however, is effected only for frequencies on both sides of the operating frequency range by suitable energization of the ferrite material by the electron stream focusing field. In this manner both forward and backward waves are attenuated at frequencies adjacent the operating range where selfoscillations are likely to occur.

Another embodiment of the present invention employs a helical waveguide coupled to an electron stream by appropriate openings at either the center or at one side thereof. A longitudinal magnetic field is used for both focusing the electron stream and for developing unidirectional attenuating characteristics in the waveguide structure by simultaneously energizing a ribbon helix constituted of ferrite material disposed parallel to and spaced from an inner wall of the guide. This structure has the advantage in that it does not have any discontinuities to detrimentally reflect portions of the electromagnetic wave being propagated along the path of the electron stream.

It is therefore an object of the present invention to provide an improved traveling-wave tube wherein the tendency to self-oscillate is minimized.

Another object of the invention is to provide a travelingwave tube incorporating a slow-wave structure having unidirectional attenuating characteristics.

Still another object of the invention is to provide an improved apparatus employing ferrite materials in conjunction with the electron stream focusing field to effect unidirectional attenuation in the wave guiding structures of traveling-wave tubes.

A further object of the present invention is to incorporate a plurality of ferrite slabs in a traveling-wave tube to effect unidirectional attenuation wherein substantially equal quantities of heat are dissipated in each ferrite slab.

A still further object of the present invention is to provide a traveling-wave tube having selective bidirectional attenuating characteristics adjacent its operating frequency range.

The novel features which are believed to be charactertic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which several embodiments of the invention are illustrated by way of example. It is to be expressly understood, however` that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.

Fig. l is a diagrammatic sectional view of an embodiment of the traveling-wave tube of the present invention together with associated circuitry;

Figs. 2 and 3 are sectional views of the tube of Fig. 1 taken on lines 2-2 and 3--3 of Fig. 1, respectively;

Figs. 4, 5 and 6 are explanatory views of the magnetic field configuration in the tubeof Fig. l;

Fig. 7 is a graph illustrating the permeability characteristic of a typical ferrite for positive and negative circularly polarized waves;

Fig. 8 is a graph illustrating the relative attenuation of forward and backward waves in the wave propagating structure of the tube of Fig. 1;

Figs. 9 and 10 are respectively a sectional and an elevational view illustrating an embodiment of a magnetic shunt for the ferrite members of the tube of Fig. 1;

Fig. 11 is a sectional view illustrating a modification of the embodiment of Fig. 1;

Fig. 12 is a graph illustrating the relative bidirectional attenuation characteristic for the Wave propagating structure of the tube of Fig. l1; and

Figs. 13 and 14 are diagrammatic sectional views of an alternate embodiment of the device of the present invention.

Referring now to the drawings, there is illustrated in Fig. l an embodiment of the present invention comprising an evacuated envelope 10, an electron gun 12 disposed within the envelope at the left extremity thereof as viewed in the figure for producing an electron stream, a folded waveguide structure 14 for propagating an electromagnetic signal wave to be amplified along a predetermined path for the electron stream, and a solenoid 16 disposed concentrically about the path for producing a magnetic field along the longitudinal axis of the tube.

More particularly, electron gun l2 comprises a cathode 20 with its associated heater 22 for providing an electron emitting surface, a focusing electrode 24, and an accelerating anode 26. Heater 22 is energized by a connection across a battery 28, one terminal of which is connected to cathode 20. In operation, the cathode 20 is maintained at a potential of the order of 2000 volts negative with respect to ground. This is accomplished by means of a connection from the cathode 20 to the negative terminal of a battery 30, the positive terminal of which is connected to ground. The focusing electrode 24 provides a conductive surface of revolution about the path of the electron stream at approximately 67.5 thereto. In accordance with this conguration, electrode 24 is maintained at the same potential as that of cathode 20 by means of a connection therebetween. Accelerating electrode 26 is disposed concentrically about the path of the electron stream to the right of and adjacent the focusing electrode 24, as shown. Electrode 26 is maintained at a potential of the order of 200 volts positive with respect to ground by means of a suitable connection to battery 32.

Folded waveguide structure 14 for propagating an electromagnetic wave along the path of the electron stream comprises a length of rectangular waveguide 40 that is periodically folded back and forth across the path of the electron stream. Suitable apertures are disposed in the waveguide walls to enable the stream electrons to proceed along the path. The electric field within the Waveguide is caused to concentrate about the path of the electron stream by means of ferrules 42 which connect adjacent apertures of the folded waveguide structure and protrude slightly inwards into the guide. Annular rings #i3 and d4 are disposed about the periphery of the first and last apertures in the waveguide along the path of the electron stream, respectively, to provide similar protrusions into the guide from the end apertures. Dielectric seals 46, 47 are disposed across the input and output ends of the waveguide, respectively, as shown so is to enable the envelope 10 to be evacuated. The waveguide 40 is maintained at ground potential by suit- ;hle connections thereto.

A collector electrode 50 for intercepting and collecting the electron stream is disposed at the extremity of its path farthest from the electron gun 12. Electrode is maintained at a potential of the order of from 100 to 200 volts positive with respect to ground so as to minimize secondary electron emission from its surface exposed to bombardment by the electron stream. The above is accomplished by a connection to the positive terminal of a battery 5l, the negative terminal of which is connected to ground.

ln accordance with the present invention, ferrite slabs 60, 61 are disposed on alternate sides of the electron stream for at least one period of the folded waveguide structure 14. Sectional views indicating representative locations of ferrite slabs 60, 6l are illustrated in Figs. 2 and 3. Referring to these figures, ferrite slabs 60, 6l are spaced distances a and b, respectively, from the walls nf the waveguide section 40. The dimensions a and b of the slabs 60, 61, respectively, may both equal approximately 25% of the width of the waveguide for maximum unidirectional attenuation. Alternatively, if it is desired that the power dissipated in each of the ferrite slabs 60, 61 be substantially equal, the distances a and b may be made to progressively increase for each half-period of the waveguide section 40 but retained within the range of 10% to 40% of the waveguide cross section. On the other hand, the attenuation of an electromagnetic wave propagated by folded waveguide section 14 may be made bidirectional by making each of the distances a and b equal to zero. ln this latter case, the selective attenuation characteristic of the ferrite material is made to occur outside of and adjacent to the operating frequency range as will be hereinafter explained.

Ferrite slabs 60, 6l have a thickness of the order of 0.025 inch and preferably extend completely across the narrow dimension of the waveguide 40 coextensive with the portion thereof normal to the path of the electron stream. The exposed edges of the ferrite slabs 60, 61 are slightly tapered, as shown in Fig. 1, so as to minimize their tendency to reflect portions of electromagnetic waves propagated through the guide. Ferrite slabs 60, 61 may be composed of, for example, ferrite material known commercially as Ferramic A, Ferramic G, Ferramic R-l, Ferroxcube 104, or Ferroxcube 106.

The solenoid 16, for producing the longitudinal magnetic field, is connected across an adjustable potential source 54. The voltage output of source 54 is adjusted so that solenoid 16 develops a magnetomotive force along the length of the tube depending upon the frequency of operation and the type of ferrites used which may be of the order of 1500 oersteds. In accordance with the present invention, this magnetic field is employed to both focus and direct the electron stream along its path and to produce transverse magnetic fields through the ferrite slabs 60, 61.

To illustrate more clearly the magnetic field portion of an electromagnetic wave propagated along the path of the electron stream, reference is made to Fig. 4, which shows a developed portion of the folded waveguide section 40 of Fig. l. In this figure, the instantaneous magnetic field for an electromagnetic field being propagated along the developed waveguide section 40 is shown by dash lines 70. In the operation of the tube of the present invention, magnetic fields of this configuration are propagated along the folded waveguide section 40 at a velocity designated as the phase velocity of the wave.

In order to consider the characteristics of the magnetic fields represented by dash lines in the region occupied by ferrite slab prime e. g. 61', the field will be viewed from a single point within the slab such as, for example, at point A. It is seen that the portion of the magnetic field that will intercept point A for the particular instant shown may be represented by vectors a, b c-and 'is-fas il lustrated in Fig. 4. As the wave is propagated along the waveguide section 40, point A will be successively cut by these points of the magnetic field. Thus, as viewed from point A, it is seen that, as shown in Fig. 5, the magnetic field appears as a vector that rotates in a clockwise direction at an angular velocity w1. When the moment of this rotating vector coincides with the direct-current magnetic field through the ferrite slab 61', the component of the wave described is said to be positive circularly polarized. Alternatively, if the moment of the rotating vector is in an opposite direction, the particular component described would be negative circularly polarized. Similarly, point B within slab 60" sees successive magnetic vectors e, f, g, and h as indicated in Fig. 4. As before, these vectors appear at point B as a single vector rotating in the counter-clockwise direction at an angular velocity w2 as illustrated in Fig. 6.

In accordance with the present invention, a direct-current magnetic field is produced in opposite directions through ferrite slabs 60 and 61 with respect to the direction in which the electromagnetic wave is propagated through the developed waveguide structure. This directcurrent magnetic field is directed in a manner such that the magnetic field components of the wave being propagated in the forward direction will be negative circularly polarized. In that the magnetic field intercepting ferrite slabs 60, 61 rotates in opposite directions, it is apparent that in order to have components of the propagated wave on both sides of the waveguide section 40 polarized in the same direction it is necessary that the direct-current magnetic field through ferrite slabs 60 be in a direction opposite to that through slabs 61. In accordance with the present invention, this is accomplished by folding back-to-back the successive portions of the waveguide containing ferrite slabs 60 and 61 which are disposed on opposite sides thereof.

As is generally known, the permeability characteristics for positive and negative circularly polarized waves of ferrite material are different. More particularly, the permeability for the negative circularly polarized wave is substantially constant, whereas the permeability for the positive circularly polarized wave goes through resonance for changes in frequency or magnetic field. During this resonance the power dissipated in the material increases substantially, thereby making the permeability for a positive circularly polarized wave a complex quantity. A typical permeability characteristic for a ferrite material is shown in Fig. 7 wherein ,L represents the permeability' for the negative circularly polarized wave and p=jt-jn" represents the permeability for a positive circularly polarized wave. As illustrated in this figure, lines 74, 76 and 78 represent the variation in /.t y. and n", respectively, versus frequency for circularly polarized waves. The magnitude of n", i. e. the imaginary part of a+, determines the extent to which the positive circularly polarized wave will be attenuated. As shown in the figure, maximum attenuation of the positive circularly polarized wave occurs at the resonant frequency. The point at which this resonance occurs is both a function of the frequency of the circularly polarized wave as seen by the ferrite material and the strength of the direct-current magnetic field through the ferrite.

Thus, in the operation of the device of the present invention, the current through solenoid 16 which determines the direct-current magnetic field is adjusted by means of adjustable potential source 54 to produce a magnetic field within the ferrite material corresponding to resonance at the operating frequency.

In operation of the device of the present invention, the function of the ferrite slabs 60, 61 is to attenuate electromagnetic wave energy being propagated by the waveguide section 40 in the direction from the collector 50 to electron gun 12, i. e. in the backward direction, without appreciably attenuating waves being propagated in the forward direction. The relative attenuation characteristics for a forward and backward wave for the device of the present invention are shown in Fig. 8 as lines 80 and 82, respectively.

As is evident from Fig. 8, when a single magnetic field strength is used through the ferrite slabs 60, 61, the attenuation of backward waves occurs for only a comparatively narrow range of frequencies. This attenuation range may be broadened by causing resonance within the ferrite slabs 60, 61 to occur at different frequencies within the band wherein it is desired to attenuate the backward waves. This may be accomplished by employing different types of ferrite material or, alternatively, by developing different magnetic fields within each of the ferrite slabs 60, 61. The magnetic fields within the ferrite slabs may be varied, for example, by employing slabs of different thicknesses or magnetic shunts 84, 86 shown in Figs. 9 and 10. In the latter case, the magnetic shunts 84, 86 are composed of a material which presents a low reluctance to the magnetic field produced by solenoid 16 so as to shunt a portion of the field around the ferrite slabs 60 and 61.

ln an alternative embodiment of the present invention, ferrite slabs 90 and 92 as shown in Fig. 11 are disposed in contact with the walls within the portions of the folded waveguide section 40 normal to the path of the electron stream. When disposed within a waveguide in this manner, both forward and backward waves are attenuated by substantially equal amounts. This attenuation, however, is a maximum at frequencies corresponding to resonance for the ferrite slabs 90 and 92. In accordance with the present invention, each of the ferrite slabs 90 and 92 are of at least two different thicknesses. Thus, when energized by the magnetic field produced by solenoid 16, different magnetic field intensities are developed within each of the slabs 90 and 92 which produce resonance at frequencies f1 and f2 which are adjacent the operating frequency range of the tube. In this manner, attenuation of both forward and backward waves is effectuated in the regions adjacent the operating frequency range of the tube as indicated, for example, by lines 94, 96 of Fig. 12 thereby minimizing any tendency of the tube to break into self-oscillation due to a poor impedance match of folded waveguide structure 14 with the input and output circuits in these ranges. It is evident that this selective attenuation may be produced by magnetic shunts or by the use of different ferrites in the manner previously described.

In another embodiment of the present invention illustrated in Fig. 13, a helical wave propagating structure 100 is employed in lieu of the folded waveguide structure 14 of the device shown and described in connection with Fig. 1, the remaining elements being substantially the same. Helical wave propagating structure 100 comprises a length of rectangular waveguide 102 which is edge-wound about the path of the electron stream at a uniform pitch. The wall of the waveguide within the evacuated envelope and adjacent the path of the electron stream is removed so that an electromagnetic wave propagated within each turn of the waveguide will combine to form a wave capable of interacting with the electron stream.

In accordance with the present invention, a ribbon helix 104 of ferrite material is disposed within the waveguide 102 coextensive with the edge-wound portion thereof and spaced from the outer wall 106. In general, the distance between the ribbon helix 104 and the outer wall 106 of the waveguide may be from 10% to 30% of the width of the guide to produce optimum unidirectional attenuation. In operation, the magnetic field produced by solenoid 16 provides focusing for the electron stream and in addition, constitutes the field which energizes the ferrite helix 104 in a direction transverse to the waveguide 102. As before, voltage source 54 is adjusted to produce a magnetic field necessary to effect resonance in the ferrite material at the desired frequency. In the event that it is desired to effect resonance over a broad range of frequencies, the thickness of the ribbon helix 104 could be tapered to cause the magnetic field within the ferrite material to progressively increase or decrease.

What is claimed is:

1. A traveling-wave tube comprising a waveguide structure having a periodic relationship with respect to a predetermined path whereby electromagnetic waves capable of being propagated by said waveguide structure form concomitant waves along said path having velocities substantially less than the velocity of light, at least one ferrite member disposed within said waveguide structure, said ferrite member being composed of longitudinal segments parallel to said predetermined path and transverse to the direction of propagation of said electromagnetic waves through said waveguide structure, means for producing an electron stream, and means for producing a predetermined longitudinal magnetic field through said waveguide structure and parallel to said predetermined path to constrain said electron stream therealong and to develop a magnetomotive force across said longitudinal segments to attenuate at least a portion of the circularly polarized components of said electromagnetic waves.

2. A traveling-wave tube comprising a conductive member providing a longitudinal rectangular enclosure for propagating electromagnetic waves, said longitudinal rectangular enclosure having periodically spaced apertures and being folded bach and forth in a manner to cause said apertures to define a predetermined path, a plurality of ferrite members disposed within said enclosure, said ferrite members being constituted of longitudinal segments parallel to said predetermined path and transverse to the direction of propagation of said electromagnetic waves through said longitudinal rectangular enclosure, means for producing an electron stream, and means for producing a predetermined longitudinal magnetic field through said conductive member and parallel to said predetermined path to constrain said electron stream therealong and to develop a magnetomotive force across said longitudinal segments to attenuate at least a portion of the circularly polarized components of said electromagnetic waves.

3. A traveling-wave tube comprising a conductive member providing a longitudinal rectangular enclosure for propagating electromagnetic waves, said longitudinal rectangular enclosure having periodically spaced apertures through the broad sides thereof, and being folded back and forth in a manner to cause said apertures to define a predetermined path, a plurality of ferrite slabs disposed on alternate sides of said path within said longitudinal enclosure, said ferrite slabs being constituted of longitudinal segments disposed parallel to said path and transverse to the direction of propagation of said electromagnetic waves through said longitudinal rectangular enclosure, means for producing an electron stream, and means for producing a predetermined longitudinal magnetic field through said conductive member and parallel to said predetermined path to constrain said electron stream therealong and to develop a magnetomotive force across said longitudinal segments to unidirectionally attenuate said electromagnetic waves.

4. The traveling-wave tube as defined in claim 3 wherein said ferrite slabs are of different thicknesses whereby ditferent magnetic field strengths are produced within individual ones of said longitudinal segments of said ferrite slabs, thereby to unidirectionally attenuate said electromagnetic waves over a broad band of frequencies.

5. The traveling-wave tube as defined in claim 3 Wherein said ferrite slabs are spaced from 10% to 40% of the width of said rectangular enclosure from the nearest respective side thereof.

6. The traveling-wave tube as defined in claim 3 including additional means for providing a magnetic shunt across the longitudinal segments of at least one of said ferrite slabs, thereby to unidirectionally attenuate said electromagnetic waves at selected frequencies.

7. A traveling-wave tube for amplifying microwave signals over a predetermined frequency range, said tube comprising a conductive member providing a folded longitudinal rectangular enclosure for propagating electromagnetic waves, `said longitudinal rectangular enclosure having periodically spaced apertures through the broad sides thereof to define a predetermined path, at least one ferrite member having a surface disposed contiguous to a narrow side of said rectangular enclosure, means for producing an electron stream, and means for producing a predetermined longitudinal magnetic field through said conductive member and parallel to said predetermined path to constrain `said electron stream therealong and to develop a magnetomotive force across said ferrite member to bidirectionally attenuate electromagnetic Waves having frequencies adjacent said predetermined frequency range.

8. A traveling-wave tube comprising a slow-wave structure for propagating electromagnetic waves, said slow-wave structure including a rectangular waveguide edge-wound at a uniform pitch about a predetermined path, said waveguide having a longitudinal aperture in the side thereof adjacent said path, and a tape helix composed of ferrite material disposed within said edgewound waveguide and spaced from the side thereof farthest from said predetermined path; means for producing an electron stream; and means for producing a predetermined longitudinal magnetic field through said slow-wave structure and parallel to said predetermined path to constrain said electron stream therealong and to develop a magnetomotive force across the width of the tape of said tape helix to unidirectionally attenuate said electromagnetic waves.

9. The traveling-wave tube as defined in claim 8 wherein said tape helix is spaced from 10% to 40% of the width of said rectangular waveguide from the side thereof farthest from said predetermined path.

l0. The traveling-wave tube as defined in claim 8 wherein the thickness of said tape helix is progressively increased thereby to unidirectionally attenuate said electromagnetic waves over a broad range of frequencies.

References Cited in the file of this patent UNITED STATES PATENTS 2,644,930 Luhrs et al. July 7, 1953 2,653,270 Kompfner Sept. 22, 1953 2,660,689 Touraton et al. Nov. 24, 1953 2,672,572 Tiley Mar. i6, 1954

US473856A 1954-12-08 1954-12-08 Traveling-wave tube Expired - Lifetime US2806972A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US473856A US2806972A (en) 1954-12-08 1954-12-08 Traveling-wave tube

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US473856A US2806972A (en) 1954-12-08 1954-12-08 Traveling-wave tube

Publications (1)

Publication Number Publication Date
US2806972A true US2806972A (en) 1957-09-17

Family

ID=23881300

Family Applications (1)

Application Number Title Priority Date Filing Date
US473856A Expired - Lifetime US2806972A (en) 1954-12-08 1954-12-08 Traveling-wave tube

Country Status (1)

Country Link
US (1) US2806972A (en)

Cited By (146)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2871396A (en) * 1956-08-21 1959-01-27 British Thomson Houston Co Ltd Klystrons
US2880357A (en) * 1955-10-21 1959-03-31 Varian Associates Electron cavity resonator tube apparatus
US2896120A (en) * 1955-12-23 1959-07-21 Bosch Gmbh Robert Ignition noise suppressor
US2896174A (en) * 1955-01-27 1959-07-21 Bell Telephone Labor Inc Nonreciprocal wave transmission
US2914699A (en) * 1957-12-03 1959-11-24 Hughes Aircraft Co Low noise electron gun
US2922917A (en) * 1953-12-21 1960-01-26 Bell Telephone Labor Inc Nonreciprocal elements in microwave tubes
US2923899A (en) * 1960-02-02 Ferrite
US2924792A (en) * 1956-03-23 1960-02-09 Bell Telephone Labor Inc Wave guide filter
US2930927A (en) * 1957-09-30 1960-03-29 Hughes Aircraft Co Traveling-wave tube
US2948870A (en) * 1956-03-13 1960-08-09 Bell Telephone Labor Inc Microwave mode suppressors
US2948868A (en) * 1955-11-14 1960-08-09 Bell Telephone Labor Inc Frequency sensitive electromagnetic wave device
US2951999A (en) * 1958-04-21 1960-09-06 Itt Constant impedance attenuator
US2953708A (en) * 1957-09-30 1960-09-20 Sperry Rand Corp Traveling-wave tube attenuator
US2954505A (en) * 1955-01-11 1960-09-27 Csf Ultra high frequency discharge tubes
US2956245A (en) * 1956-04-16 1960-10-11 Sperry Rand Corp Microwave isolator
US2956246A (en) * 1957-07-08 1960-10-11 Sperry Rand Corp Microwave unilateral transducer
US2970274A (en) * 1958-03-21 1961-01-31 Bell Telephone Labor Inc Solid state amplifier
US2970242A (en) * 1956-03-30 1961-01-31 Varian Associates High frequency electron tube apparatus
US3023384A (en) * 1955-09-22 1962-02-27 Bell Telephone Labor Inc Broad-band ferrite polarization rotator
US3041554A (en) * 1956-12-31 1962-06-26 Hughes Aircraft Co Ultrabandwidth miniature resonance absorption isolator
US3063028A (en) * 1960-05-05 1962-11-06 Bell Telephone Labor Inc Enhanced gyromagnetic effect in nonreciprocal wave transmission
US3071740A (en) * 1960-03-21 1963-01-01 Raytheon Co Non-reciprocal tem device
US3075159A (en) * 1957-07-26 1963-01-22 Sylvania Electric Prod High power ferrite isolator having ferrite materials of differing curie temperature
US3078425A (en) * 1956-07-12 1963-02-19 Sperry Rand Corp Non-reciprocal tm mode transducer
US3090015A (en) * 1957-03-27 1963-05-14 Raytheon Co Electrical phase shifters
US3090930A (en) * 1957-12-26 1963-05-21 Bell Telephone Labor Inc Variable gyromagnetic wave transmission device
US3095546A (en) * 1956-03-01 1963-06-25 Sylvania Electric Prod Gyromagnetic isolator using a nonuniform magnetic bias
US3099806A (en) * 1961-01-16 1963-07-30 Hughes Aircraft Co High-power resonance absorption isolator having ferrite slab offset from polepieces so as to be non-uniformly magnetized
US3142026A (en) * 1961-07-05 1964-07-21 Bell Telephone Labor Inc Broadband resonance gyromagnetic absorption isolator with magnetic field of increased strength toward narrow wall
US3200353A (en) * 1962-02-14 1965-08-10 Cutler Hammer Inc Microwave structure utilizing ferrite coupling means
DE1516400B1 (en) * 1965-04-30 1971-06-09 Varian Associates Traveling wave tube
US9154966B2 (en) 2013-11-06 2015-10-06 At&T Intellectual Property I, Lp Surface-wave communications and methods thereof
US9209902B2 (en) 2013-12-10 2015-12-08 At&T Intellectual Property I, L.P. Quasi-optical coupler
US9312919B1 (en) 2014-10-21 2016-04-12 At&T Intellectual Property I, Lp Transmission device with impairment compensation and methods for use therewith
US9461706B1 (en) 2015-07-31 2016-10-04 At&T Intellectual Property I, Lp Method and apparatus for exchanging communication signals
US9490869B1 (en) 2015-05-14 2016-11-08 At&T Intellectual Property I, L.P. Transmission medium having multiple cores and methods for use therewith
US9503189B2 (en) 2014-10-10 2016-11-22 At&T Intellectual Property I, L.P. Method and apparatus for arranging communication sessions in a communication system
US9509415B1 (en) 2015-06-25 2016-11-29 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a fundamental wave mode on a transmission medium
US9520945B2 (en) 2014-10-21 2016-12-13 At&T Intellectual Property I, L.P. Apparatus for providing communication services and methods thereof
US9525210B2 (en) 2014-10-21 2016-12-20 At&T Intellectual Property I, L.P. Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9525524B2 (en) 2013-05-31 2016-12-20 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9531427B2 (en) 2014-11-20 2016-12-27 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9564947B2 (en) 2014-10-21 2017-02-07 At&T Intellectual Property I, L.P. Guided-wave transmission device with diversity and methods for use therewith
US9577307B2 (en) 2014-10-21 2017-02-21 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9608740B2 (en) 2015-07-15 2017-03-28 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9608692B2 (en) 2015-06-11 2017-03-28 At&T Intellectual Property I, L.P. Repeater and methods for use therewith
US9615269B2 (en) 2014-10-02 2017-04-04 At&T Intellectual Property I, L.P. Method and apparatus that provides fault tolerance in a communication network
US9628116B2 (en) 2015-07-14 2017-04-18 At&T Intellectual Property I, L.P. Apparatus and methods for transmitting wireless signals
US9628854B2 (en) 2014-09-29 2017-04-18 At&T Intellectual Property I, L.P. Method and apparatus for distributing content in a communication network
US9640850B2 (en) 2015-06-25 2017-05-02 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a non-fundamental wave mode on a transmission medium
US9653770B2 (en) 2014-10-21 2017-05-16 At&T Intellectual Property I, L.P. Guided wave coupler, coupling module and methods for use therewith
US9667317B2 (en) 2015-06-15 2017-05-30 At&T Intellectual Property I, L.P. Method and apparatus for providing security using network traffic adjustments
US9680670B2 (en) 2014-11-20 2017-06-13 At&T Intellectual Property I, L.P. Transmission device with channel equalization and control and methods for use therewith
US9685992B2 (en) 2014-10-03 2017-06-20 At&T Intellectual Property I, L.P. Circuit panel network and methods thereof
US9692101B2 (en) 2014-08-26 2017-06-27 At&T Intellectual Property I, L.P. Guided wave couplers for coupling electromagnetic waves between a waveguide surface and a surface of a wire
US9699785B2 (en) 2012-12-05 2017-07-04 At&T Intellectual Property I, L.P. Backhaul link for distributed antenna system
US9705561B2 (en) 2015-04-24 2017-07-11 At&T Intellectual Property I, L.P. Directional coupling device and methods for use therewith
US9705571B2 (en) 2015-09-16 2017-07-11 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system
US9722318B2 (en) 2015-07-14 2017-08-01 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US9729197B2 (en) 2015-10-01 2017-08-08 At&T Intellectual Property I, L.P. Method and apparatus for communicating network management traffic over a network
US9735833B2 (en) 2015-07-31 2017-08-15 At&T Intellectual Property I, L.P. Method and apparatus for communications management in a neighborhood network
US9742462B2 (en) 2014-12-04 2017-08-22 At&T Intellectual Property I, L.P. Transmission medium and communication interfaces and methods for use therewith
US9748626B2 (en) 2015-05-14 2017-08-29 At&T Intellectual Property I, L.P. Plurality of cables having different cross-sectional shapes which are bundled together to form a transmission medium
US9749053B2 (en) 2015-07-23 2017-08-29 At&T Intellectual Property I, L.P. Node device, repeater and methods for use therewith
US9749013B2 (en) 2015-03-17 2017-08-29 At&T Intellectual Property I, L.P. Method and apparatus for reducing attenuation of electromagnetic waves guided by a transmission medium
US9755697B2 (en) 2014-09-15 2017-09-05 At&T Intellectual Property I, L.P. Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves
US9762289B2 (en) 2014-10-14 2017-09-12 At&T Intellectual Property I, L.P. Method and apparatus for transmitting or receiving signals in a transportation system
US9769128B2 (en) 2015-09-28 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for encryption of communications over a network
US9769020B2 (en) 2014-10-21 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for responding to events affecting communications in a communication network
US9780834B2 (en) 2014-10-21 2017-10-03 At&T Intellectual Property I, L.P. Method and apparatus for transmitting electromagnetic waves
US9793955B2 (en) 2015-04-24 2017-10-17 At&T Intellectual Property I, Lp Passive electrical coupling device and methods for use therewith
US9793951B2 (en) 2015-07-15 2017-10-17 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9793954B2 (en) 2015-04-28 2017-10-17 At&T Intellectual Property I, L.P. Magnetic coupling device and methods for use therewith
US9800327B2 (en) 2014-11-20 2017-10-24 At&T Intellectual Property I, L.P. Apparatus for controlling operations of a communication device and methods thereof
US9820146B2 (en) 2015-06-12 2017-11-14 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9836957B2 (en) 2015-07-14 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for communicating with premises equipment
US9838896B1 (en) 2016-12-09 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for assessing network coverage
US9847566B2 (en) 2015-07-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a field of a signal to mitigate interference
US9847850B2 (en) 2014-10-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a mode of communication in a communication network
US9853342B2 (en) 2015-07-14 2017-12-26 At&T Intellectual Property I, L.P. Dielectric transmission medium connector and methods for use therewith
US9860075B1 (en) 2016-08-26 2018-01-02 At&T Intellectual Property I, L.P. Method and communication node for broadband distribution
US9866309B2 (en) 2015-06-03 2018-01-09 At&T Intellectual Property I, Lp Host node device and methods for use therewith
US9865911B2 (en) 2015-06-25 2018-01-09 At&T Intellectual Property I, L.P. Waveguide system for slot radiating first electromagnetic waves that are combined into a non-fundamental wave mode second electromagnetic wave on a transmission medium
US9871282B2 (en) 2015-05-14 2018-01-16 At&T Intellectual Property I, L.P. At least one transmission medium having a dielectric surface that is covered at least in part by a second dielectric
US9871283B2 (en) 2015-07-23 2018-01-16 At&T Intellectual Property I, Lp Transmission medium having a dielectric core comprised of plural members connected by a ball and socket configuration
US9876264B2 (en) 2015-10-02 2018-01-23 At&T Intellectual Property I, Lp Communication system, guided wave switch and methods for use therewith
US9876605B1 (en) 2016-10-21 2018-01-23 At&T Intellectual Property I, L.P. Launcher and coupling system to support desired guided wave mode
US9876571B2 (en) 2015-02-20 2018-01-23 At&T Intellectual Property I, Lp Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9882257B2 (en) 2015-07-14 2018-01-30 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9882277B2 (en) 2015-10-02 2018-01-30 At&T Intellectual Property I, Lp Communication device and antenna assembly with actuated gimbal mount
US9893795B1 (en) 2016-12-07 2018-02-13 At&T Intellectual Property I, Lp Method and repeater for broadband distribution
US9904535B2 (en) 2015-09-14 2018-02-27 At&T Intellectual Property I, L.P. Method and apparatus for distributing software
US9906269B2 (en) 2014-09-17 2018-02-27 At&T Intellectual Property I, L.P. Monitoring and mitigating conditions in a communication network
US9912027B2 (en) 2015-07-23 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9912419B1 (en) 2016-08-24 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for managing a fault in a distributed antenna system
US9912381B2 (en) 2015-06-03 2018-03-06 At&T Intellectual Property I, Lp Network termination and methods for use therewith
US9911020B1 (en) 2016-12-08 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for tracking via a radio frequency identification device
US9913139B2 (en) 2015-06-09 2018-03-06 At&T Intellectual Property I, L.P. Signal fingerprinting for authentication of communicating devices
US9917341B2 (en) 2015-05-27 2018-03-13 At&T Intellectual Property I, L.P. Apparatus and method for launching electromagnetic waves and for modifying radial dimensions of the propagating electromagnetic waves
US9927517B1 (en) 2016-12-06 2018-03-27 At&T Intellectual Property I, L.P. Apparatus and methods for sensing rainfall
US9948354B2 (en) 2015-04-28 2018-04-17 At&T Intellectual Property I, L.P. Magnetic coupling device with reflective plate and methods for use therewith
US9948333B2 (en) 2015-07-23 2018-04-17 At&T Intellectual Property I, L.P. Method and apparatus for wireless communications to mitigate interference
US9954287B2 (en) 2014-11-20 2018-04-24 At&T Intellectual Property I, L.P. Apparatus for converting wireless signals and electromagnetic waves and methods thereof
US9967173B2 (en) 2015-07-31 2018-05-08 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9973940B1 (en) 2017-02-27 2018-05-15 At&T Intellectual Property I, L.P. Apparatus and methods for dynamic impedance matching of a guided wave launcher
US9991580B2 (en) 2016-10-21 2018-06-05 At&T Intellectual Property I, L.P. Launcher and coupling system for guided wave mode cancellation
US9998870B1 (en) 2016-12-08 2018-06-12 At&T Intellectual Property I, L.P. Method and apparatus for proximity sensing
US9997819B2 (en) 2015-06-09 2018-06-12 At&T Intellectual Property I, L.P. Transmission medium and method for facilitating propagation of electromagnetic waves via a core
US9999038B2 (en) 2013-05-31 2018-06-12 At&T Intellectual Property I, L.P. Remote distributed antenna system
US10009065B2 (en) 2012-12-05 2018-06-26 At&T Intellectual Property I, L.P. Backhaul link for distributed antenna system
US10009063B2 (en) 2015-09-16 2018-06-26 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having an out-of-band reference signal
US10009901B2 (en) 2015-09-16 2018-06-26 At&T Intellectual Property I, L.P. Method, apparatus, and computer-readable storage medium for managing utilization of wireless resources between base stations
US10009067B2 (en) 2014-12-04 2018-06-26 At&T Intellectual Property I, L.P. Method and apparatus for configuring a communication interface
US10020844B2 (en) 2016-12-06 2018-07-10 T&T Intellectual Property I, L.P. Method and apparatus for broadcast communication via guided waves
US10020587B2 (en) 2015-07-31 2018-07-10 At&T Intellectual Property I, L.P. Radial antenna and methods for use therewith
US10027397B2 (en) 2016-12-07 2018-07-17 At&T Intellectual Property I, L.P. Distributed antenna system and methods for use therewith
US10033108B2 (en) 2015-07-14 2018-07-24 At&T Intellectual Property I, L.P. Apparatus and methods for generating an electromagnetic wave having a wave mode that mitigates interference
US10033107B2 (en) 2015-07-14 2018-07-24 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US10044409B2 (en) 2015-07-14 2018-08-07 At&T Intellectual Property I, L.P. Transmission medium and methods for use therewith
US10051629B2 (en) 2015-09-16 2018-08-14 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having an in-band reference signal
US10051483B2 (en) 2015-10-16 2018-08-14 At&T Intellectual Property I, L.P. Method and apparatus for directing wireless signals
US10069535B2 (en) 2016-12-08 2018-09-04 At&T Intellectual Property I, L.P. Apparatus and methods for launching electromagnetic waves having a certain electric field structure
US10074890B2 (en) 2015-10-02 2018-09-11 At&T Intellectual Property I, L.P. Communication device and antenna with integrated light assembly
US10079661B2 (en) 2015-09-16 2018-09-18 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having a clock reference
US10090606B2 (en) 2015-07-15 2018-10-02 At&T Intellectual Property I, L.P. Antenna system with dielectric array and methods for use therewith
US10090594B2 (en) 2016-11-23 2018-10-02 At&T Intellectual Property I, L.P. Antenna system having structural configurations for assembly
US10103801B2 (en) 2015-06-03 2018-10-16 At&T Intellectual Property I, L.P. Host node device and methods for use therewith
US10103422B2 (en) 2016-12-08 2018-10-16 At&T Intellectual Property I, L.P. Method and apparatus for mounting network devices
US10135147B2 (en) 2016-10-18 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for launching guided waves via an antenna
US10136434B2 (en) 2015-09-16 2018-11-20 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having an ultra-wideband control channel
US10135145B2 (en) 2016-12-06 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for generating an electromagnetic wave along a transmission medium
US10135146B2 (en) 2016-10-18 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for launching guided waves via circuits
US10142086B2 (en) 2015-06-11 2018-11-27 At&T Intellectual Property I, L.P. Repeater and methods for use therewith
US10139820B2 (en) 2016-12-07 2018-11-27 At&T Intellectual Property I, L.P. Method and apparatus for deploying equipment of a communication system
US10148016B2 (en) 2015-07-14 2018-12-04 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array
US10144036B2 (en) 2015-01-30 2018-12-04 At&T Intellectual Property I, L.P. Method and apparatus for mitigating interference affecting a propagation of electromagnetic waves guided by a transmission medium
US10154493B2 (en) 2015-06-03 2018-12-11 At&T Intellectual Property I, L.P. Network termination and methods for use therewith
US10170840B2 (en) 2015-07-14 2019-01-01 At&T Intellectual Property I, L.P. Apparatus and methods for sending or receiving electromagnetic signals
US10168695B2 (en) 2016-12-07 2019-01-01 At&T Intellectual Property I, L.P. Method and apparatus for controlling an unmanned aircraft
US10178445B2 (en) 2016-11-23 2019-01-08 At&T Intellectual Property I, L.P. Methods, devices, and systems for load balancing between a plurality of waveguides
US10205655B2 (en) 2015-07-14 2019-02-12 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array and multiple communication paths
US10225025B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Method and apparatus for detecting a fault in a communication system
US10224634B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Methods and apparatus for adjusting an operational characteristic of an antenna
US10243270B2 (en) 2016-12-07 2019-03-26 At&T Intellectual Property I, L.P. Beam adaptive multi-feed dielectric antenna system and methods for use therewith
US10243784B2 (en) 2014-11-20 2019-03-26 At&T Intellectual Property I, L.P. System for generating topology information and methods thereof
US10264586B2 (en) 2016-12-09 2019-04-16 At&T Mobility Ii Llc Cloud-based packet controller and methods for use therewith

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2644930A (en) * 1949-03-24 1953-07-07 Gen Precision Lab Inc Microwave polarization rotating device and coupling network
US2653270A (en) * 1944-06-08 1953-09-22 English Electric Valve Co Ltd High-frequency energy interchange device
US2660689A (en) * 1947-08-01 1953-11-24 Int Standard Electric Corp Ultrahigh-frequency vacuum tube
US2672572A (en) * 1947-07-18 1954-03-16 Philco Corp Traveling wave tube

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2653270A (en) * 1944-06-08 1953-09-22 English Electric Valve Co Ltd High-frequency energy interchange device
US2672572A (en) * 1947-07-18 1954-03-16 Philco Corp Traveling wave tube
US2660689A (en) * 1947-08-01 1953-11-24 Int Standard Electric Corp Ultrahigh-frequency vacuum tube
US2644930A (en) * 1949-03-24 1953-07-07 Gen Precision Lab Inc Microwave polarization rotating device and coupling network

Cited By (200)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2923899A (en) * 1960-02-02 Ferrite
US2922917A (en) * 1953-12-21 1960-01-26 Bell Telephone Labor Inc Nonreciprocal elements in microwave tubes
US2954505A (en) * 1955-01-11 1960-09-27 Csf Ultra high frequency discharge tubes
US2896174A (en) * 1955-01-27 1959-07-21 Bell Telephone Labor Inc Nonreciprocal wave transmission
US3023384A (en) * 1955-09-22 1962-02-27 Bell Telephone Labor Inc Broad-band ferrite polarization rotator
US2880357A (en) * 1955-10-21 1959-03-31 Varian Associates Electron cavity resonator tube apparatus
US2948868A (en) * 1955-11-14 1960-08-09 Bell Telephone Labor Inc Frequency sensitive electromagnetic wave device
US2896120A (en) * 1955-12-23 1959-07-21 Bosch Gmbh Robert Ignition noise suppressor
US3095546A (en) * 1956-03-01 1963-06-25 Sylvania Electric Prod Gyromagnetic isolator using a nonuniform magnetic bias
US2948870A (en) * 1956-03-13 1960-08-09 Bell Telephone Labor Inc Microwave mode suppressors
US2924792A (en) * 1956-03-23 1960-02-09 Bell Telephone Labor Inc Wave guide filter
US2970242A (en) * 1956-03-30 1961-01-31 Varian Associates High frequency electron tube apparatus
US2956245A (en) * 1956-04-16 1960-10-11 Sperry Rand Corp Microwave isolator
US3078425A (en) * 1956-07-12 1963-02-19 Sperry Rand Corp Non-reciprocal tm mode transducer
US2871396A (en) * 1956-08-21 1959-01-27 British Thomson Houston Co Ltd Klystrons
US3041554A (en) * 1956-12-31 1962-06-26 Hughes Aircraft Co Ultrabandwidth miniature resonance absorption isolator
US3090015A (en) * 1957-03-27 1963-05-14 Raytheon Co Electrical phase shifters
US2956246A (en) * 1957-07-08 1960-10-11 Sperry Rand Corp Microwave unilateral transducer
US3075159A (en) * 1957-07-26 1963-01-22 Sylvania Electric Prod High power ferrite isolator having ferrite materials of differing curie temperature
US2930927A (en) * 1957-09-30 1960-03-29 Hughes Aircraft Co Traveling-wave tube
US2953708A (en) * 1957-09-30 1960-09-20 Sperry Rand Corp Traveling-wave tube attenuator
US2914699A (en) * 1957-12-03 1959-11-24 Hughes Aircraft Co Low noise electron gun
US3090930A (en) * 1957-12-26 1963-05-21 Bell Telephone Labor Inc Variable gyromagnetic wave transmission device
US2970274A (en) * 1958-03-21 1961-01-31 Bell Telephone Labor Inc Solid state amplifier
US2951999A (en) * 1958-04-21 1960-09-06 Itt Constant impedance attenuator
US3071740A (en) * 1960-03-21 1963-01-01 Raytheon Co Non-reciprocal tem device
US3063028A (en) * 1960-05-05 1962-11-06 Bell Telephone Labor Inc Enhanced gyromagnetic effect in nonreciprocal wave transmission
US3099806A (en) * 1961-01-16 1963-07-30 Hughes Aircraft Co High-power resonance absorption isolator having ferrite slab offset from polepieces so as to be non-uniformly magnetized
US3142026A (en) * 1961-07-05 1964-07-21 Bell Telephone Labor Inc Broadband resonance gyromagnetic absorption isolator with magnetic field of increased strength toward narrow wall
US3200353A (en) * 1962-02-14 1965-08-10 Cutler Hammer Inc Microwave structure utilizing ferrite coupling means
DE1516400B1 (en) * 1965-04-30 1971-06-09 Varian Associates Traveling wave tube
US9788326B2 (en) 2012-12-05 2017-10-10 At&T Intellectual Property I, L.P. Backhaul link for distributed antenna system
US9699785B2 (en) 2012-12-05 2017-07-04 At&T Intellectual Property I, L.P. Backhaul link for distributed antenna system
US10194437B2 (en) 2012-12-05 2019-01-29 At&T Intellectual Property I, L.P. Backhaul link for distributed antenna system
US10009065B2 (en) 2012-12-05 2018-06-26 At&T Intellectual Property I, L.P. Backhaul link for distributed antenna system
US9525524B2 (en) 2013-05-31 2016-12-20 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9930668B2 (en) 2013-05-31 2018-03-27 At&T Intellectual Property I, L.P. Remote distributed antenna system
US10091787B2 (en) 2013-05-31 2018-10-02 At&T Intellectual Property I, L.P. Remote distributed antenna system
US10051630B2 (en) 2013-05-31 2018-08-14 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9999038B2 (en) 2013-05-31 2018-06-12 At&T Intellectual Property I, L.P. Remote distributed antenna system
US9661505B2 (en) 2013-11-06 2017-05-23 At&T Intellectual Property I, L.P. Surface-wave communications and methods thereof
US9154966B2 (en) 2013-11-06 2015-10-06 At&T Intellectual Property I, Lp Surface-wave communications and methods thereof
US9467870B2 (en) 2013-11-06 2016-10-11 At&T Intellectual Property I, L.P. Surface-wave communications and methods thereof
US9674711B2 (en) 2013-11-06 2017-06-06 At&T Intellectual Property I, L.P. Surface-wave communications and methods thereof
US9794003B2 (en) 2013-12-10 2017-10-17 At&T Intellectual Property I, L.P. Quasi-optical coupler
US9479266B2 (en) 2013-12-10 2016-10-25 At&T Intellectual Property I, L.P. Quasi-optical coupler
US9209902B2 (en) 2013-12-10 2015-12-08 At&T Intellectual Property I, L.P. Quasi-optical coupler
US9876584B2 (en) 2013-12-10 2018-01-23 At&T Intellectual Property I, L.P. Quasi-optical coupler
US9692101B2 (en) 2014-08-26 2017-06-27 At&T Intellectual Property I, L.P. Guided wave couplers for coupling electromagnetic waves between a waveguide surface and a surface of a wire
US10096881B2 (en) 2014-08-26 2018-10-09 At&T Intellectual Property I, L.P. Guided wave couplers for coupling electromagnetic waves to an outer surface of a transmission medium
US9755697B2 (en) 2014-09-15 2017-09-05 At&T Intellectual Property I, L.P. Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves
US9768833B2 (en) 2014-09-15 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves
US9906269B2 (en) 2014-09-17 2018-02-27 At&T Intellectual Property I, L.P. Monitoring and mitigating conditions in a communication network
US10063280B2 (en) 2014-09-17 2018-08-28 At&T Intellectual Property I, L.P. Monitoring and mitigating conditions in a communication network
US9628854B2 (en) 2014-09-29 2017-04-18 At&T Intellectual Property I, L.P. Method and apparatus for distributing content in a communication network
US9998932B2 (en) 2014-10-02 2018-06-12 At&T Intellectual Property I, L.P. Method and apparatus that provides fault tolerance in a communication network
US9973416B2 (en) 2014-10-02 2018-05-15 At&T Intellectual Property I, L.P. Method and apparatus that provides fault tolerance in a communication network
US9615269B2 (en) 2014-10-02 2017-04-04 At&T Intellectual Property I, L.P. Method and apparatus that provides fault tolerance in a communication network
US9685992B2 (en) 2014-10-03 2017-06-20 At&T Intellectual Property I, L.P. Circuit panel network and methods thereof
US9503189B2 (en) 2014-10-10 2016-11-22 At&T Intellectual Property I, L.P. Method and apparatus for arranging communication sessions in a communication system
US9866276B2 (en) 2014-10-10 2018-01-09 At&T Intellectual Property I, L.P. Method and apparatus for arranging communication sessions in a communication system
US9973299B2 (en) 2014-10-14 2018-05-15 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a mode of communication in a communication network
US9762289B2 (en) 2014-10-14 2017-09-12 At&T Intellectual Property I, L.P. Method and apparatus for transmitting or receiving signals in a transportation system
US9847850B2 (en) 2014-10-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a mode of communication in a communication network
US9520945B2 (en) 2014-10-21 2016-12-13 At&T Intellectual Property I, L.P. Apparatus for providing communication services and methods thereof
US9871558B2 (en) 2014-10-21 2018-01-16 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9571209B2 (en) 2014-10-21 2017-02-14 At&T Intellectual Property I, L.P. Transmission device with impairment compensation and methods for use therewith
US9705610B2 (en) 2014-10-21 2017-07-11 At&T Intellectual Property I, L.P. Transmission device with impairment compensation and methods for use therewith
US9948355B2 (en) 2014-10-21 2018-04-17 At&T Intellectual Property I, L.P. Apparatus for providing communication services and methods thereof
US9577307B2 (en) 2014-10-21 2017-02-21 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9954286B2 (en) 2014-10-21 2018-04-24 At&T Intellectual Property I, L.P. Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9960808B2 (en) 2014-10-21 2018-05-01 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9653770B2 (en) 2014-10-21 2017-05-16 At&T Intellectual Property I, L.P. Guided wave coupler, coupling module and methods for use therewith
US9312919B1 (en) 2014-10-21 2016-04-12 At&T Intellectual Property I, Lp Transmission device with impairment compensation and methods for use therewith
US9564947B2 (en) 2014-10-21 2017-02-07 At&T Intellectual Property I, L.P. Guided-wave transmission device with diversity and methods for use therewith
US9596001B2 (en) 2014-10-21 2017-03-14 At&T Intellectual Property I, L.P. Apparatus for providing communication services and methods thereof
US9627768B2 (en) 2014-10-21 2017-04-18 At&T Intellectual Property I, L.P. Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9780834B2 (en) 2014-10-21 2017-10-03 At&T Intellectual Property I, L.P. Method and apparatus for transmitting electromagnetic waves
US9525210B2 (en) 2014-10-21 2016-12-20 At&T Intellectual Property I, L.P. Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9577306B2 (en) 2014-10-21 2017-02-21 At&T Intellectual Property I, L.P. Guided-wave transmission device and methods for use therewith
US9876587B2 (en) 2014-10-21 2018-01-23 At&T Intellectual Property I, L.P. Transmission device with impairment compensation and methods for use therewith
US9769020B2 (en) 2014-10-21 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for responding to events affecting communications in a communication network
US9912033B2 (en) 2014-10-21 2018-03-06 At&T Intellectual Property I, Lp Guided wave coupler, coupling module and methods for use therewith
US9954287B2 (en) 2014-11-20 2018-04-24 At&T Intellectual Property I, L.P. Apparatus for converting wireless signals and electromagnetic waves and methods thereof
US10243784B2 (en) 2014-11-20 2019-03-26 At&T Intellectual Property I, L.P. System for generating topology information and methods thereof
US9749083B2 (en) 2014-11-20 2017-08-29 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9712350B2 (en) 2014-11-20 2017-07-18 At&T Intellectual Property I, L.P. Transmission device with channel equalization and control and methods for use therewith
US9680670B2 (en) 2014-11-20 2017-06-13 At&T Intellectual Property I, L.P. Transmission device with channel equalization and control and methods for use therewith
US9544006B2 (en) 2014-11-20 2017-01-10 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9531427B2 (en) 2014-11-20 2016-12-27 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9800327B2 (en) 2014-11-20 2017-10-24 At&T Intellectual Property I, L.P. Apparatus for controlling operations of a communication device and methods thereof
US9742521B2 (en) 2014-11-20 2017-08-22 At&T Intellectual Property I, L.P. Transmission device with mode division multiplexing and methods for use therewith
US9742462B2 (en) 2014-12-04 2017-08-22 At&T Intellectual Property I, L.P. Transmission medium and communication interfaces and methods for use therewith
US10009067B2 (en) 2014-12-04 2018-06-26 At&T Intellectual Property I, L.P. Method and apparatus for configuring a communication interface
US10144036B2 (en) 2015-01-30 2018-12-04 At&T Intellectual Property I, L.P. Method and apparatus for mitigating interference affecting a propagation of electromagnetic waves guided by a transmission medium
US9876570B2 (en) 2015-02-20 2018-01-23 At&T Intellectual Property I, Lp Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9876571B2 (en) 2015-02-20 2018-01-23 At&T Intellectual Property I, Lp Guided-wave transmission device with non-fundamental mode propagation and methods for use therewith
US9749013B2 (en) 2015-03-17 2017-08-29 At&T Intellectual Property I, L.P. Method and apparatus for reducing attenuation of electromagnetic waves guided by a transmission medium
US9705561B2 (en) 2015-04-24 2017-07-11 At&T Intellectual Property I, L.P. Directional coupling device and methods for use therewith
US9831912B2 (en) 2015-04-24 2017-11-28 At&T Intellectual Property I, Lp Directional coupling device and methods for use therewith
US9793955B2 (en) 2015-04-24 2017-10-17 At&T Intellectual Property I, Lp Passive electrical coupling device and methods for use therewith
US10224981B2 (en) 2015-04-24 2019-03-05 At&T Intellectual Property I, Lp Passive electrical coupling device and methods for use therewith
US9948354B2 (en) 2015-04-28 2018-04-17 At&T Intellectual Property I, L.P. Magnetic coupling device with reflective plate and methods for use therewith
US9793954B2 (en) 2015-04-28 2017-10-17 At&T Intellectual Property I, L.P. Magnetic coupling device and methods for use therewith
US9748626B2 (en) 2015-05-14 2017-08-29 At&T Intellectual Property I, L.P. Plurality of cables having different cross-sectional shapes which are bundled together to form a transmission medium
US9871282B2 (en) 2015-05-14 2018-01-16 At&T Intellectual Property I, L.P. At least one transmission medium having a dielectric surface that is covered at least in part by a second dielectric
US9887447B2 (en) 2015-05-14 2018-02-06 At&T Intellectual Property I, L.P. Transmission medium having multiple cores and methods for use therewith
US9490869B1 (en) 2015-05-14 2016-11-08 At&T Intellectual Property I, L.P. Transmission medium having multiple cores and methods for use therewith
US9917341B2 (en) 2015-05-27 2018-03-13 At&T Intellectual Property I, L.P. Apparatus and method for launching electromagnetic waves and for modifying radial dimensions of the propagating electromagnetic waves
US10154493B2 (en) 2015-06-03 2018-12-11 At&T Intellectual Property I, L.P. Network termination and methods for use therewith
US9935703B2 (en) 2015-06-03 2018-04-03 At&T Intellectual Property I, L.P. Host node device and methods for use therewith
US9866309B2 (en) 2015-06-03 2018-01-09 At&T Intellectual Property I, Lp Host node device and methods for use therewith
US9967002B2 (en) 2015-06-03 2018-05-08 At&T Intellectual I, Lp Network termination and methods for use therewith
US9912382B2 (en) 2015-06-03 2018-03-06 At&T Intellectual Property I, Lp Network termination and methods for use therewith
US10050697B2 (en) 2015-06-03 2018-08-14 At&T Intellectual Property I, L.P. Host node device and methods for use therewith
US9912381B2 (en) 2015-06-03 2018-03-06 At&T Intellectual Property I, Lp Network termination and methods for use therewith
US10103801B2 (en) 2015-06-03 2018-10-16 At&T Intellectual Property I, L.P. Host node device and methods for use therewith
US9997819B2 (en) 2015-06-09 2018-06-12 At&T Intellectual Property I, L.P. Transmission medium and method for facilitating propagation of electromagnetic waves via a core
US9913139B2 (en) 2015-06-09 2018-03-06 At&T Intellectual Property I, L.P. Signal fingerprinting for authentication of communicating devices
US9608692B2 (en) 2015-06-11 2017-03-28 At&T Intellectual Property I, L.P. Repeater and methods for use therewith
US10142010B2 (en) 2015-06-11 2018-11-27 At&T Intellectual Property I, L.P. Repeater and methods for use therewith
US10142086B2 (en) 2015-06-11 2018-11-27 At&T Intellectual Property I, L.P. Repeater and methods for use therewith
US10027398B2 (en) 2015-06-11 2018-07-17 At&T Intellectual Property I, Lp Repeater and methods for use therewith
US9820146B2 (en) 2015-06-12 2017-11-14 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9667317B2 (en) 2015-06-15 2017-05-30 At&T Intellectual Property I, L.P. Method and apparatus for providing security using network traffic adjustments
US9882657B2 (en) 2015-06-25 2018-01-30 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a fundamental wave mode on a transmission medium
US9509415B1 (en) 2015-06-25 2016-11-29 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a fundamental wave mode on a transmission medium
US10069185B2 (en) 2015-06-25 2018-09-04 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a non-fundamental wave mode on a transmission medium
US9640850B2 (en) 2015-06-25 2017-05-02 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a non-fundamental wave mode on a transmission medium
US9865911B2 (en) 2015-06-25 2018-01-09 At&T Intellectual Property I, L.P. Waveguide system for slot radiating first electromagnetic waves that are combined into a non-fundamental wave mode second electromagnetic wave on a transmission medium
US9787412B2 (en) 2015-06-25 2017-10-10 At&T Intellectual Property I, L.P. Methods and apparatus for inducing a fundamental wave mode on a transmission medium
US10090601B2 (en) 2015-06-25 2018-10-02 At&T Intellectual Property I, L.P. Waveguide system and methods for inducing a non-fundamental wave mode on a transmission medium
US9882257B2 (en) 2015-07-14 2018-01-30 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9947982B2 (en) 2015-07-14 2018-04-17 At&T Intellectual Property I, Lp Dielectric transmission medium connector and methods for use therewith
US9847566B2 (en) 2015-07-14 2017-12-19 At&T Intellectual Property I, L.P. Method and apparatus for adjusting a field of a signal to mitigate interference
US10230148B2 (en) 2015-07-14 2019-03-12 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9628116B2 (en) 2015-07-14 2017-04-18 At&T Intellectual Property I, L.P. Apparatus and methods for transmitting wireless signals
US10170840B2 (en) 2015-07-14 2019-01-01 At&T Intellectual Property I, L.P. Apparatus and methods for sending or receiving electromagnetic signals
US9836957B2 (en) 2015-07-14 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for communicating with premises equipment
US10033107B2 (en) 2015-07-14 2018-07-24 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US10033108B2 (en) 2015-07-14 2018-07-24 At&T Intellectual Property I, L.P. Apparatus and methods for generating an electromagnetic wave having a wave mode that mitigates interference
US9929755B2 (en) 2015-07-14 2018-03-27 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US9722318B2 (en) 2015-07-14 2017-08-01 At&T Intellectual Property I, L.P. Method and apparatus for coupling an antenna to a device
US9853342B2 (en) 2015-07-14 2017-12-26 At&T Intellectual Property I, L.P. Dielectric transmission medium connector and methods for use therewith
US10148016B2 (en) 2015-07-14 2018-12-04 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array
US10205655B2 (en) 2015-07-14 2019-02-12 At&T Intellectual Property I, L.P. Apparatus and methods for communicating utilizing an antenna array and multiple communication paths
US10044409B2 (en) 2015-07-14 2018-08-07 At&T Intellectual Property I, L.P. Transmission medium and methods for use therewith
US9608740B2 (en) 2015-07-15 2017-03-28 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US9793951B2 (en) 2015-07-15 2017-10-17 At&T Intellectual Property I, L.P. Method and apparatus for launching a wave mode that mitigates interference
US10090606B2 (en) 2015-07-15 2018-10-02 At&T Intellectual Property I, L.P. Antenna system with dielectric array and methods for use therewith
US9912027B2 (en) 2015-07-23 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9871283B2 (en) 2015-07-23 2018-01-16 At&T Intellectual Property I, Lp Transmission medium having a dielectric core comprised of plural members connected by a ball and socket configuration
US9749053B2 (en) 2015-07-23 2017-08-29 At&T Intellectual Property I, L.P. Node device, repeater and methods for use therewith
US9948333B2 (en) 2015-07-23 2018-04-17 At&T Intellectual Property I, L.P. Method and apparatus for wireless communications to mitigate interference
US9806818B2 (en) 2015-07-23 2017-10-31 At&T Intellectual Property I, Lp Node device, repeater and methods for use therewith
US10074886B2 (en) 2015-07-23 2018-09-11 At&T Intellectual Property I, L.P. Dielectric transmission medium comprising a plurality of rigid dielectric members coupled together in a ball and socket configuration
US10020587B2 (en) 2015-07-31 2018-07-10 At&T Intellectual Property I, L.P. Radial antenna and methods for use therewith
US9461706B1 (en) 2015-07-31 2016-10-04 At&T Intellectual Property I, Lp Method and apparatus for exchanging communication signals
US9967173B2 (en) 2015-07-31 2018-05-08 At&T Intellectual Property I, L.P. Method and apparatus for authentication and identity management of communicating devices
US9838078B2 (en) 2015-07-31 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for exchanging communication signals
US9735833B2 (en) 2015-07-31 2017-08-15 At&T Intellectual Property I, L.P. Method and apparatus for communications management in a neighborhood network
US9904535B2 (en) 2015-09-14 2018-02-27 At&T Intellectual Property I, L.P. Method and apparatus for distributing software
US10051629B2 (en) 2015-09-16 2018-08-14 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having an in-band reference signal
US10136434B2 (en) 2015-09-16 2018-11-20 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having an ultra-wideband control channel
US10225842B2 (en) 2015-09-16 2019-03-05 At&T Intellectual Property I, L.P. Method, device and storage medium for communications using a modulated signal and a reference signal
US10009901B2 (en) 2015-09-16 2018-06-26 At&T Intellectual Property I, L.P. Method, apparatus, and computer-readable storage medium for managing utilization of wireless resources between base stations
US9705571B2 (en) 2015-09-16 2017-07-11 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system
US10009063B2 (en) 2015-09-16 2018-06-26 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having an out-of-band reference signal
US10079661B2 (en) 2015-09-16 2018-09-18 At&T Intellectual Property I, L.P. Method and apparatus for use with a radio distributed antenna system having a clock reference
US9769128B2 (en) 2015-09-28 2017-09-19 At&T Intellectual Property I, L.P. Method and apparatus for encryption of communications over a network
US9729197B2 (en) 2015-10-01 2017-08-08 At&T Intellectual Property I, L.P. Method and apparatus for communicating network management traffic over a network
US10074890B2 (en) 2015-10-02 2018-09-11 At&T Intellectual Property I, L.P. Communication device and antenna with integrated light assembly
US9882277B2 (en) 2015-10-02 2018-01-30 At&T Intellectual Property I, Lp Communication device and antenna assembly with actuated gimbal mount
US9876264B2 (en) 2015-10-02 2018-01-23 At&T Intellectual Property I, Lp Communication system, guided wave switch and methods for use therewith
US10051483B2 (en) 2015-10-16 2018-08-14 At&T Intellectual Property I, L.P. Method and apparatus for directing wireless signals
US9912419B1 (en) 2016-08-24 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for managing a fault in a distributed antenna system
US9860075B1 (en) 2016-08-26 2018-01-02 At&T Intellectual Property I, L.P. Method and communication node for broadband distribution
US10135146B2 (en) 2016-10-18 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for launching guided waves via circuits
US10135147B2 (en) 2016-10-18 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for launching guided waves via an antenna
US9991580B2 (en) 2016-10-21 2018-06-05 At&T Intellectual Property I, L.P. Launcher and coupling system for guided wave mode cancellation
US9876605B1 (en) 2016-10-21 2018-01-23 At&T Intellectual Property I, L.P. Launcher and coupling system to support desired guided wave mode
US10225025B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Method and apparatus for detecting a fault in a communication system
US10224634B2 (en) 2016-11-03 2019-03-05 At&T Intellectual Property I, L.P. Methods and apparatus for adjusting an operational characteristic of an antenna
US10090594B2 (en) 2016-11-23 2018-10-02 At&T Intellectual Property I, L.P. Antenna system having structural configurations for assembly
US10178445B2 (en) 2016-11-23 2019-01-08 At&T Intellectual Property I, L.P. Methods, devices, and systems for load balancing between a plurality of waveguides
US10135145B2 (en) 2016-12-06 2018-11-20 At&T Intellectual Property I, L.P. Apparatus and methods for generating an electromagnetic wave along a transmission medium
US9927517B1 (en) 2016-12-06 2018-03-27 At&T Intellectual Property I, L.P. Apparatus and methods for sensing rainfall
US10020844B2 (en) 2016-12-06 2018-07-10 T&T Intellectual Property I, L.P. Method and apparatus for broadcast communication via guided waves
US9893795B1 (en) 2016-12-07 2018-02-13 At&T Intellectual Property I, Lp Method and repeater for broadband distribution
US10243270B2 (en) 2016-12-07 2019-03-26 At&T Intellectual Property I, L.P. Beam adaptive multi-feed dielectric antenna system and methods for use therewith
US10168695B2 (en) 2016-12-07 2019-01-01 At&T Intellectual Property I, L.P. Method and apparatus for controlling an unmanned aircraft
US10027397B2 (en) 2016-12-07 2018-07-17 At&T Intellectual Property I, L.P. Distributed antenna system and methods for use therewith
US10139820B2 (en) 2016-12-07 2018-11-27 At&T Intellectual Property I, L.P. Method and apparatus for deploying equipment of a communication system
US9911020B1 (en) 2016-12-08 2018-03-06 At&T Intellectual Property I, L.P. Method and apparatus for tracking via a radio frequency identification device
US9998870B1 (en) 2016-12-08 2018-06-12 At&T Intellectual Property I, L.P. Method and apparatus for proximity sensing
US10103422B2 (en) 2016-12-08 2018-10-16 At&T Intellectual Property I, L.P. Method and apparatus for mounting network devices
US10069535B2 (en) 2016-12-08 2018-09-04 At&T Intellectual Property I, L.P. Apparatus and methods for launching electromagnetic waves having a certain electric field structure
US9838896B1 (en) 2016-12-09 2017-12-05 At&T Intellectual Property I, L.P. Method and apparatus for assessing network coverage
US10264586B2 (en) 2016-12-09 2019-04-16 At&T Mobility Ii Llc Cloud-based packet controller and methods for use therewith
US9973940B1 (en) 2017-02-27 2018-05-15 At&T Intellectual Property I, L.P. Apparatus and methods for dynamic impedance matching of a guided wave launcher

Similar Documents

Publication Publication Date Title
US2741718A (en) High frequency apparatus
US2367295A (en) Electron discharge device
US2575383A (en) High-frequency amplifying device
Elsasser Attenuation in a dielectric circular rod
US2584308A (en) Electronic tube of the traveling wave type
US2409222A (en) Electron discharge device
US2602148A (en) High-frequency amplifier
US2511407A (en) Amplifying valve of the progressive wave type
US2368031A (en) Electron discharge device
US2683238A (en) Microwave amplifier
US2584597A (en) Traveling wave tube
Ramo The electronic-wave theory of velocity-modulation tubes
US2888595A (en) Travelling wave delay tubes of the magnetron type
Kompfner The traveling-wave tube as amplifier at microwaves
US2654047A (en) Beam traveling wave amplifier tube
US3432721A (en) Beam plasma high frequency wave generating system
US2653270A (en) High-frequency energy interchange device
US2304540A (en) Generating apparatus
US2320860A (en) Electron discharge apparatus
US2725499A (en) High frequency amplifying device
US2170219A (en) Ultra high frequency oscillator
US2312723A (en) Electron discharge device
US2956200A (en) Periodically focused traveling wave tube with tapered phase velocity
US2566087A (en) Tube of the magnetron type for ultra-short waves
US2289756A (en) Electron tube and circuits employing it