US2405174A - Transmission control network - Google Patents

Transmission control network Download PDF

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Publication number
US2405174A
US2405174A US444660A US44466042A US2405174A US 2405174 A US2405174 A US 2405174A US 444660 A US444660 A US 444660A US 44466042 A US44466042 A US 44466042A US 2405174 A US2405174 A US 2405174A
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US
United States
Prior art keywords
line
network
impedance
characteristic impedance
networks
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
US444660A
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English (en)
Inventor
Alford Andrew
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.)
Mackay Radio & Telegraph Co
MACKAY RADIO AND TELEGRAPH Co
Original Assignee
Mackay Radio & Telegraph 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 Mackay Radio & Telegraph Co filed Critical Mackay Radio & Telegraph Co
Priority to US444660A priority Critical patent/US2405174A/en
Priority to FR927575D priority patent/FR927575A/fr
Priority to CH266743D priority patent/CH266743A/de
Application granted granted Critical
Publication of US2405174A publication Critical patent/US2405174A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P5/00—Coupling devices of the waveguide type
    • H01P5/02—Coupling devices of the waveguide type with invariable factor of coupling

Definitions

  • This invention relates to high frequency transmission systems and more particularly to impedance matching networks for high frequency lines.
  • the stated objects may be achieved by coupling to the transmission line a conductor of given characteristic impedance value, the length being determined by the characteristic impedance of the line and the standing wave ratio in the line and the position along the line being determined by the selected length and the characteristic impedance of the line.
  • Figs. 2 and 3 are curves showing characteristics of networks used in myjnvention
  • Fig. 4 illustrates one form of my invention applied to a line feeding an antenna.
  • FIG. 5 illustrates a further modification of my invention
  • FIG. 6 illustrates still another form of my invention.
  • impedance matching networks are often cumbersome, particularly when used on high frequency supply leads to radio antenna. I have discovered that an impedance matching may be achieved by use of a simpler network consisting of a relatively long narrow conductive arrangement fastened to the conductors,
  • Fig. 1 the effect of the network is demonstrated.
  • a high frequency source I is shown connected over a transmission line 2, to a load impedance 3 which is made substantially equal to thecharacteristic impedance of line 2, In such a transmission line there will be no standing waves.
  • a conductor 4 is coupled to the line it is found that standing waves are produced on the line, as shown at 5.
  • the conductor has a characteristic impedance of Z0 and a length 1. With such a relationship it is found that the spacing of the conductor from the standing waves maximum, Imax is given by the value P.
  • Fig. 1A is shown such a system in which the source I is connected over a transmission line 2 to a load 3a, the line normally having standing waves as indicated at 5a.
  • the network 4 of length Z and characteristic impedance Z0 serves to match the impedance f the line as illustrated in this figure.
  • this form of network will readily serve to secure impedance match in most transmission lines if the proper dimensions and position are chosen.
  • the network is of small vertical dimension it will exert very little bending stress on the line during high winds or the like, and is, therefore, particularly Well suited for use on open wire high frequency transmission lines which are exposed to the weather.
  • Fig. 2 is shown a family of curves, representing different values of the ratio of characteristic impedance Z0 of the line to the characteristic Z0 of these networks, plotted with the length of the units in electrical degrees against the standing wave ratio Q, that is Fig. 3 then shows a set of curves for determining the spacing P, the spacing 'P being shown in electrical degrees plotted against the length Z in electrical degrees.
  • the curves of Fig. 2 are first consulted. Assume, for example, the standing wave ratio is 3. It is seen that there are three sets of networks which will be satisfactory depending upon the characteristic impedance of the networks which it is desired to use.
  • the characteristic impedance of the network may be readily calculated for any fiat metal objects of the type illustrated in Fig. 1 or for metal rod forms such as shown in Fig. 5. Accordingly, the desired width of plate or diameter of rod is found by calculation and the length is then determined by reference to Fig. 2.
  • curve 22 is chosen. It will be seen that this requires a network having a length of substantially 60 electrical degrees. Turning then to Fig. 3, the length Z found from Fig. 2 is laid out on the horizontal axis, and the spacing P can'then be determined from this. In the given example it is found that the spacing P must then be made of the order of 2.5 degrees from the current maximum.
  • any desired, impedance matching network may be secured from a family of curves as shown in Figs. 2 and 3. While only a few curves have been shown it is readily apparent that the number of curves which may be provided is substantially infinite, and, therefore, the variety of networks that can be provided in accordance with my invention is also infinite.
  • Fig. 4. is illustrated an arrangement in which transmission line 48 is coupled to a dipole antenna 4
  • Matching sections 42, 43 are provided in each of the lines. If these sections are found to be too short, additional sections 44, 45 may be hung on the ends thereof. Further, if the sections 42, 43 are found to be too long they y be readily trimmed oif, being made of light sheet metal.
  • Fig. 5 is illustrated how another form of network comprising sections of line 52, 55 of different diameter than the conductors of line 3! may be applied to the line. Th impedance of the line sections may be readily calculated and they may be applied to the line by use of the diagrams of Figs. '2 and 3 or similar diagrams calculated for this form of conductor.
  • Fig. 6 a form of network applied to a transmission line 46 connected to an antenna 4!, in which each of the units BI, 52 comprises a plurality of small loops of wire fastened to the transmitting conductor. If desired these wire loops may be reinforced by a third wire 63, 64, as shown. Such a construction is preferable to the netting or screening since the openings are much larger and do not facilitate the formation of sheets of sleet.
  • the impedance matching with such networks as shown in 63, 64 can be accomplished in a similar manner to that described above.
  • the network such as shown at El, 62, has the additional advantage overthe use of the sheets in that the length of the units may be determined by the number of loops added to the line, so that the proper adjustment and length can be easily made in the field.
  • the impedance of such networks as shown at 61, 62 may be calculated, this calculation is quite involved and it is often more feasible to find the impedance thereof by experiment.
  • the impedance of such networks may be determined by use of the arrangement similar to that shown in Fig. 1. Since the standing wave ratio on the line which is created by the unit networks can be readily measured, and the characteristic impedance Z0 is known, the characteristic impedance of any unit of length I may be readily calculated after taking the measurements from the known functions. In order to secure the required data loops of a particular size may be strung on a matched impedance line such as shown in Fig. 1, and the information as to the standing wave ratio produced thereby determined for different lengths of network having a given looping dimension.
  • a family of curves similar to those shown in Fig. 2 may be readily plotted experimentally.
  • the spacing P may be determined at the same time and a set of experimental curves similar in type to that shown in Fig. 3 may be plotted.
  • the standing wave ratio of the line may be first measured and the desired length of loop network may be derived from the sets of curves in a similar manner to that previously described.
  • this has once been determined all that is necessary is to fasten the conductor forming the loops to the transmission line at one point and proceed to make the number of intermediate loops necessary to produce the desired length of network. It is, therefore, seen that this particular form of network arrangement shown in Fig. 6 is readily applicable to transmission lines in the field and may be applied by any attendant who is in charge of the transmission lines.
  • any desired form of impedance network can be used so long as the conductor is chosen with respect to the unit impedance value and taking into consideration the characteristic impedance of the line, the standing wave ratio of the line and the proper position determined by this characteristic impedance and the selected length.
  • a separate readily applied impedance matching network comprising conductive means having a given characteristic impedance connected to a conductor of said line throughout substantially the entire length of said conductive means, said conductive means having an overall length determined from the selection of a characteristic among those existing between standing wave ratio in said transmission line and network lengths, for different ratios between characteristic impedance of said line and of networks including approximately said given characteristic impedance, and said conductive means having a position along said line with respect to the standing wave maximum of standing waves in said line determined by the selection of one among the existing characteristics between network lengths and positions for difierent ratios between the characteristic impedance of said line and of networks including approximately said given characteristic impedance.
  • a separate readily applied impedance matching network comprising conductive means connected to each conductor of the line throughout substantially the entire length of said conductive means, said conductive means defining a predetermined area in the plane of said conductor and having a given characteristic impedance and an overall length determined from the selection of a characteristic among those existing between standing wave ratio in said transmitting line and network lengths for different ratios between characteristic impedanc of said line and of networks including approximately said given characteristic impedance, and said conductive means having a position along said line with respect to the standing wave maximum of standing waves in said line determined by the selection of one among the existing characteristics between network lengths and positions for different ratios between the characteristic impedance of said line and of networks including approximately said given characteristic impedance.
  • a high frequency transmission line system comprising a high frequency transmitting line including an impedance matching network comprising conductive mea-ns having a given characteristic impedance connected to a conductor of said line, said conductive means having an overall length determined from the selection of a characteristic among those existing between standing wave ratio in said transmission line and network lengths, for difierent ratios between characteristic impedance of said line and of networks including approximately said given characteristic impedance, and said conductive means having a position along said line with respect to the standing wave maximum of standing Waves in said line determined by the selection of one among the existing characteristics between network lengths and positions for different ratios between the characteristic impedance of said line and of networks including approximately said given characteristic impedance, said conductive means comprising a series of looped wires each terminating at said conductor.

Landscapes

  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
US444660A 1942-05-27 1942-05-27 Transmission control network Expired - Lifetime US2405174A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US444660A US2405174A (en) 1942-05-27 1942-05-27 Transmission control network
FR927575D FR927575A (fr) 1942-05-27 1946-06-01 Réseaux de contrôle de transmission
CH266743D CH266743A (de) 1942-05-27 1946-07-27 Impedanzanpassungsnetzwerk auf einer Hochfrequenzleitung.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US444660A US2405174A (en) 1942-05-27 1942-05-27 Transmission control network

Publications (1)

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US2405174A true US2405174A (en) 1946-08-06

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US444660A Expired - Lifetime US2405174A (en) 1942-05-27 1942-05-27 Transmission control network

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US (1) US2405174A (fr)
CH (1) CH266743A (fr)
FR (1) FR927575A (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2475198A (en) * 1945-03-30 1949-07-05 Bell Telephone Labor Inc Tunable lecher circuit
US2490957A (en) * 1945-06-30 1949-12-13 Rca Corp Antenna system
US2554295A (en) * 1946-09-30 1951-05-22 Rca Corp Variable inductance device
US2653299A (en) * 1942-02-04 1953-09-22 Sperry Corp High-frequency power measuring apparatus
US2656515A (en) * 1942-03-31 1953-10-20 Sperry Corp Wave guide impedance transformer
US2666857A (en) * 1949-12-29 1954-01-19 Bendix Aviat Corp Radioactive test circuit
US2762983A (en) * 1952-11-28 1956-09-11 Collins Radio Co Variable inductance device
US2833995A (en) * 1952-05-08 1958-05-06 Itt Microwave transmission line
US3015823A (en) * 1959-02-17 1962-01-02 Gen Electric Helical antenna null suppressor
US3210833A (en) * 1962-12-07 1965-10-12 Comp Generale Electricite Storage battery assembly machines
DE1240197B (de) * 1954-02-19 1967-05-11 Siemens Ag Aus mehreren, in Kette geschalteten Lecherleitungsabschnitten bestehende Stichleitung und daraus aufgebautes Filter
US20160329126A1 (en) * 2014-01-21 2016-11-10 Delphi Technologies, Inc. Impedance matching device

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2653299A (en) * 1942-02-04 1953-09-22 Sperry Corp High-frequency power measuring apparatus
US2656515A (en) * 1942-03-31 1953-10-20 Sperry Corp Wave guide impedance transformer
US2475198A (en) * 1945-03-30 1949-07-05 Bell Telephone Labor Inc Tunable lecher circuit
US2490957A (en) * 1945-06-30 1949-12-13 Rca Corp Antenna system
US2554295A (en) * 1946-09-30 1951-05-22 Rca Corp Variable inductance device
US2666857A (en) * 1949-12-29 1954-01-19 Bendix Aviat Corp Radioactive test circuit
US2833995A (en) * 1952-05-08 1958-05-06 Itt Microwave transmission line
US2762983A (en) * 1952-11-28 1956-09-11 Collins Radio Co Variable inductance device
DE1240197B (de) * 1954-02-19 1967-05-11 Siemens Ag Aus mehreren, in Kette geschalteten Lecherleitungsabschnitten bestehende Stichleitung und daraus aufgebautes Filter
US3015823A (en) * 1959-02-17 1962-01-02 Gen Electric Helical antenna null suppressor
US3210833A (en) * 1962-12-07 1965-10-12 Comp Generale Electricite Storage battery assembly machines
US20160329126A1 (en) * 2014-01-21 2016-11-10 Delphi Technologies, Inc. Impedance matching device
US9928941B2 (en) * 2014-01-21 2018-03-27 Delphi Technologies, Inc. Impedance matching device

Also Published As

Publication number Publication date
CH266743A (de) 1950-02-15
FR927575A (fr) 1947-11-03

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