US1775544A - Stabilization of tuned radio frequency amplifiers - Google Patents
Stabilization of tuned radio frequency amplifiers Download PDFInfo
- Publication number
- US1775544A US1775544A US276470A US27647028A US1775544A US 1775544 A US1775544 A US 1775544A US 276470 A US276470 A US 276470A US 27647028 A US27647028 A US 27647028A US 1775544 A US1775544 A US 1775544A
- Authority
- US
- United States
- Prior art keywords
- circuit
- tuned
- radio frequency
- dielectric
- coil
- 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
Links
- 230000006641 stabilisation Effects 0.000 title description 3
- 238000011105 stabilization Methods 0.000 title description 3
- 230000000087 stabilizing effect Effects 0.000 description 31
- 230000008878 coupling Effects 0.000 description 29
- 238000010168 coupling process Methods 0.000 description 29
- 238000005859 coupling reaction Methods 0.000 description 29
- 238000010521 absorption reaction Methods 0.000 description 12
- 239000010425 asbestos Substances 0.000 description 12
- 229910052895 riebeckite Inorganic materials 0.000 description 12
- 230000010355 oscillation Effects 0.000 description 6
- 230000003321 amplification Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000003199 nucleic acid amplification method Methods 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000003472 neutralizing effect Effects 0.000 description 3
- 238000004804 winding Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/08—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements
- H03F1/12—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements by use of attenuating means
- H03F1/13—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements by use of attenuating means in discharge-tube amplifiers
Definitions
- the present invention relates to tuned radio frequency amplifiers and more particularly to an improved means for stabilizing the operation of such amplifiers.
- Amplifiers of this character usually employ space discharge devices of the vacuum tube type provided with three or more elements and connected in cascade by suitable tuned radio frequency transformers or impedances.
- an improved stabilizing circuit including an element having a high dielectric hysteresis loss is associated with the coils or tuned circuits of a tuned radio frequency amplifier and is adjusted so as to give this desired result.
- I take advantage of a property of a dielectric, such as asbestos, which has a very high dielectric hysteresis constant.
- a dielectric such as asbestos
- I have found that asbestos has a power factor of about 30% for all frequencies up to 100,000 cycles, and it also appears that it has substantially the same power factor at much higher frequencies.
- the expression high dielectric constant is used herein to designate any suitable material oi this general character.
- the high energy absorption of asbestos can be demonstrated by simply placing a piece of asbestos tape on top of the tuning coils of a radio frequency amplifier. If the amplifier is near the critical point of oscillation this alone will stop it.
- Fig. 1 is a diagrammatic representation of the principle on which the stabilizing means of my invention operates;
- Fig. 2 is a wiring diagram of a tuned radio frequency amplifier provided with a stabilizing circuit in accordance with my invention, and
- Fig. 3 is a wiring diagram of a similar amplifier provided with a modification of such stabilizing circuit.
- 5 and 6 are plates of conducting material connected with circuit wires '7 and separated by a strip of dielectric material 8 having very high dielectric hysteresis constant with respect to air, for example, such iece of asbestos tape.
- This serves as an electrostatic coupling between the plates which may be connected with a tuned radio frequency amplifier to form a stabilizing circuit therefor, the stabilizing circuit being completed through the amplifier coil or tuning system for example, and the dielectric between the plates acting as the stabilizing or energy absorbing means.
- the plates may be taken as representing conducting bodies or portions of a circuit which may be coupled electrostatically by the dielectric 8 to increase the positive resistance of the circuit.
- One stabilizing circuit arrangement embodying a condenser means of this type is shown in Fig. 2. Referring to dig.
- the second transformer forming the output or load circuit therefor.
- This may be taken as representing any suitable radio frequency or similar amplifier circuit including a tuning coil or tuned circuit connected with a space discharge device which tends to set up osclllatlons in the tuned circuit.
- the oscillations occur by reason of the plategrid capacity coupling of the tube which tends to produce the effect of a negative resistance greater than the positive resistance ofthe grid circuit-
- the problem as stated hereinbefore is then to provide ameans inconnection with or associated with the grid or tuned circuit, preferably at the tuning coil, or impedance, which will set up an artificial increase in the positive resistance of the circuit to equal or slightly overcome the negative resistance in the tube or other space discharge device connected with the coil circuit, at all wave lengths, that is, at all frequencies over which the tuning system is to operate.
- One means for effectingv this result and for carrying out the principles underlying the showing in 1, in connection with the tuned radio frequency amplifier above described comprises a small coil 15 which is wound with two layers 16 and 17, with an asbestos tape 18 between the layers.
- the tape may, however, be of any other suitable material having similar dielectric properties, and serves as an energy absorbing means in connection with the coil.
- the natural period of this coil should occur preferably at ahigher frequency than the highest frequency at which the amplifier circuit is to be used.
- One terminal of this coil is connected through a circuit wire 19 to the ground or low potential end of the tuned cir cuit or secondary 12.
- the other terminal is connected by a wire 20 to a piece of conducting material 21, such as a piece of tinfoil for example, which may have an area of about square inch and is laid adjacent to the high tension or grid end of the tuned circuit or secondary 12 and-separated therefrom by a piece of asbestos tape 22.
- a piece of conducting material 21 such as a piece of tinfoil for example, which may have an area of about square inch and is laid adjacent to the high tension or grid end of the tuned circuit or secondary 12 and-separated therefrom by a piece of asbestos tape 22.
- the small absorption coil 15 is preferably coupled magnetically to the tuning coil or tuned circuit by being placed inside it or in front of it, as indicated in the drawing.
- This arrangement provides a stabilizing circuit 19-16-1720-21-22 in connection with the tuned circuit or secondary 12 in which stabilizing circuit is provided an en ergy absorbing or stabilizing condenser comprising the plate 21, the adjacent portion of the winding 12 and the dielectric 22.
- the stabilizing means or circuit there are a number of variables which can be used so as' to grade the positive resistance of the tuned circuit with reference to the wave length or frequency in any way desired.
- the principal variables are the inductances of-the absorbing coil 15, the capacity coupling through the stabilizing condenser 21-22 and the magnetic coupling of the stabilizing winding 15 with the grid coil or tuned circuit.
- the natural period of the absorption coil corresponds to a wave length which is sufiiciently shorter than the shortest Working wave length that its frequency resonance point will he higher than the highest working frequency of the amplifier.
- a suitable proportioning of the coil with reference to this natural period gives one more variable for increasing the energy absorption of the shortest wave or highest frequency to any desired degree.
- the absorption coil shown at 23 may be made of asbestos or dielectric covered wire, the dielectric being indicated at 24, and may be wound on the same cylinder the tuning coil or inductance 12, which is shown connected together with tube 9, in the same radio frequency amplifier circuit as in Fig. 1.
- the spacing of the coils is such as to give the desired capacity and magnetic coupling.
- it is indicated as being wound with an asbestos or dielectric covered wire which is fastened on the inside of the cylinder of the tuning coil, at the high tension or grid end, the capacity between the two windings being depended upon for the desired coupling.
- one end of the coil 23 is left open as indicated at 25.
- the stabilizing means and circuit of my invention are readily adapted for application to any radio frequency amplifier having a tuning coil or tuned circuit in connection with a space discharge device, the inter element capacity of which provides an undesirable negative resistance effect upon the tuned circuit.
- the stabilizing circuit may include only the dielectric stabilizing condenser of Fig. 1 for electrostatic coupling with the tuned circuit and in other cases may include also means such as the small coil 15 of Fig. 2 for electromagnetic coupling or a single coil such as used at 23 in Fig. 3 for providing both electrostatic and electromagnetic coupling, the coil itself being wound with dielectric covered wire, the dielectric having a high hysteresis constant.
- a radio frequency amplifier including elements providing a tuned circuit and a space discharge device connected with said tuned'circuit, of a stabilizing circuit including a condenser connected with said tuned circuit, the dielectric of said condenser having a high hysteresis constant with respect to air and being closely associated with one element of said tuned circuit.
- the combination with a radio frequency amplifier including elements providing a tuned circuit and a space discharge device connected with said tuned circuit, of a stabilizing circuit connected with said tuned circuit and provided with a condenser having a dielectric of asbestos and being closely associated with one element of said tuned circuit.
- a. tuned radio frequency amplifier comprising a tuned circuit and a space discharge device connected therewith, a stabilizing circuit including a capacity coupling having a high dielectric hysteresis constant, and an'inductance provided with coils which are spaced apart by a dielectric of the same character as the dielectric of said. coupling.
- a tuned radio frequency amplifier comprising a. tuned circuit and a space discharge device connected therewith. and a' stabilizingcircuit coupled to said tuned circuit through a'capacity coupling having a high dielectric hysteresis constant, said stabilizing circuit being tuned to a frequency higher than the highest operating frequency of said tuned circuit.
- a tuned radio frequency amplifier comprising a tuned circuit and a space discharge device connected therewith, a stabilizing circuit coupled to said tunedcircuit through a capacity coupling having a high dielectric hysteresis constant, and an inductance connected in'said stabilizing circuit and provided with coils which are spaced apart by a dielectric of the same character as the dielectric of said coupling, said inductance being magnetically coupled with the tuned circuit in opposition to said capacity coupling.
- a tuned radio frequency amplifier comprising a. tuned circuit and a space discharge device connected therewith, the combination of a stabilizing circuit including an inductance having a natural frequency response which is higher than the highest op erating frequency of said tuned circuit, and
- a tuned radio frequency amplifier comprising a tuned circuit and a space discharge device connected therewith, the combination of a stabilizing circuit including an inductance having a natural frequency response which is higher than the highest operating frequency of said tuned circuit, and an electrostatic coupling between said stabilizing circuit and said tunedcircuit, said coupling including a dielectric having a high hysteresis loss constant.
- V 8 The combination with a tuned radio frequency amplifier comprising atuned circuit and a space discharge device connected therewith, of aninduction stabilizing circuit the natural frequency response period of which is higher than the highest operating frequency of the tuned circuit, and a'dielectric having a high hysteresis constant providing an electrostatic coupling betweensai circuits.
- a tuned radio fre- 15 quency amplifier comprising a space discharge device and a tuned circuit connected therewith on which said device reacts to provide the effect of a negative resistance, and means including capacity and inductive cou- 20 plings for grading the positive resistance of the tuned circuit to neutralize said negative resistance, said capacity coupling being connected to the high potential end of saidtuned circuit and said inductive coupling being 25 connected to the low potential end of said tuned circuit.
- a tuned radio frequency amplifier comprising a space discharge device and a tunedc-ircuit connected 3o therewith on which said device reacts to provide theeffect of a negative resistance
- a neutralizing circuit including a capacity and a coil for grading the positive resistance of the tuned circuit to neutralize said negative resistance, said neutralizing circuit being coupled to said tuned circuit through said capacity and through said coil, and said coil being arranged to neutralize the effect of said capacity at the lowest operating frequency -49 of said tuned circuit.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Amplifiers (AREA)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US276470A US1775544A (en) | 1928-05-09 | 1928-05-09 | Stabilization of tuned radio frequency amplifiers |
NL45318A NL27794C (xx) | 1928-05-09 | 1929-03-09 | |
FR675174D FR675174A (fr) | 1928-05-09 | 1929-05-03 | Stabilisation des amplificateurs de t. s. f. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US276470A US1775544A (en) | 1928-05-09 | 1928-05-09 | Stabilization of tuned radio frequency amplifiers |
Publications (1)
Publication Number | Publication Date |
---|---|
US1775544A true US1775544A (en) | 1930-09-09 |
Family
ID=23056774
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US276470A Expired - Lifetime US1775544A (en) | 1928-05-09 | 1928-05-09 | Stabilization of tuned radio frequency amplifiers |
Country Status (3)
Country | Link |
---|---|
US (1) | US1775544A (xx) |
FR (1) | FR675174A (xx) |
NL (1) | NL27794C (xx) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3214634A (en) * | 1963-02-26 | 1965-10-26 | Westinghouse Electric Corp | Shatterproof valve type lightning arrester |
-
1928
- 1928-05-09 US US276470A patent/US1775544A/en not_active Expired - Lifetime
-
1929
- 1929-03-09 NL NL45318A patent/NL27794C/xx active
- 1929-05-03 FR FR675174D patent/FR675174A/fr not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3214634A (en) * | 1963-02-26 | 1965-10-26 | Westinghouse Electric Corp | Shatterproof valve type lightning arrester |
Also Published As
Publication number | Publication date |
---|---|
FR675174A (fr) | 1930-02-06 |
NL27794C (xx) | 1932-09-15 |
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