US3010082A - Hybrid ring network - Google Patents

Hybrid ring network Download PDF

Info

Publication number
US3010082A
US3010082A US300909A US30090952A US3010082A US 3010082 A US3010082 A US 3010082A US 300909 A US300909 A US 300909A US 30090952 A US30090952 A US 30090952A US 3010082 A US3010082 A US 3010082A
Authority
US
United States
Prior art keywords
ring
arm
arms
network
loop
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
US300909A
Inventor
Horace T Budenbom
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.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
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 Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US300909A priority Critical patent/US3010082A/en
Application granted granted Critical
Publication of US3010082A publication Critical patent/US3010082A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P5/00—Coupling devices of the waveguide type
    • H01P5/12—Coupling devices having more than two ports
    • H01P5/16—Conjugate devices, i.e. devices having at least one port decoupled from one other port
    • H01P5/19—Conjugate devices, i.e. devices having at least one port decoupled from one other port of the junction type
    • H01P5/22—Hybrid ring junctions
    • H01P5/222—180° rat race hybrid rings

Definitions

  • This invention relates to wave transmission networks and more particularly to hybrid ring networks.
  • the object of the invention is to improve the impedance match at certain arms of a five-arm hybrid ring.
  • a more specific object is to make the input impedances equal at all arms of a five-arm hybrid ring without incurring an appreciable loss of power.
  • a five-arm hybrid ring may be designed to have certain desirable conjugate relationships which may be utilized, for example, in branching arrangements or in networks for obtaining the complex sum of and difference between two coherent input voltages or powers. Rings of this type are disclosed, for example, in the paper by W. A. Tyrrell entitled Hybrid Circuits for Microwaves, published in the Proceedings of the I.R.E. for November 1947, and in my copending United States patent application Serial No. 52,856, filed October 5, 1942, now Patent No. 2,7 84,381 issued March 5, 1957.
  • such a ring comprises a closed transmission loop having an effective length of wavelengths A at a selected design frequency f and five transmission branches or arms connected in series with the loop at successive points thereon spaced apart by M4 at the frequency
  • these arms may be designated one to five, with a spacing of M2 between the first and the fifth.
  • the loop and the arms may be constituted by a wave guide, a coaxial cable, or some other suitable type of transmission line. If all of the arms have the same characteristic impedance Z each is terminated in an impedance Z and the loop has a characteristic impedance equal to Z /VZ there will be a good impedance match with the loop for the third arm, but a considerable mismatch for the other arms. In practice, this mismatch has been found to be of the order of three decibels, which is undesirably large for some applications, especially if high power transmission is involved.
  • this mismatch is greatly reduced, without substantial power loss, by adding a sixth series arm of characteristic impedance Z connected to the loop at a point midway between the first and the filfth arms, iteratively terminating the added arm, and providing an auxiliary transmission path between the third arm and the sixth arm.
  • the addition of this sixth terminated arm only, without the auxiliary path, will provide an impedance match at the first, second, fourth, and fifth arms, but a considerable fraction of the input power will be lost by dissipation in its termination.
  • the function of the auxiliary path is to prevent this loss of power.
  • the third and the sixth arms are connected by an auxiliary path extending across the loop and having an electrical length equal to ) ⁇ /4. If a wave guide of the hollow-pipe type is used, it may be necessary to include dielectric material within the guide to provide the required electrical length.
  • the auxiliary path includes a directional coupler connecting the third and the sixth arms.
  • FIG. 1 is a perspective View, partly cut away, of one embodiment of a hybrid ring network in accordance with the invention.
  • FIG. 2 is a similar view the invention.
  • the hybrid ring network shown in FIG. 1 comprises a section of transmission line 10 formed into a loop or ring and provided with six equally spaced transmission branches or arms, numbered consecutively 1 to 6, and an auxiliary transmission path 7.
  • the ring and the branches are made of hollow-pipe wave guide of oblong cross section, adapted to transmit electromagnetic waves having an smaller transverse dimension, as indicated by the arrow 11 in the branch '4. It and branches may also be constituted by coaxial cable or some other suitable type of transmission line.
  • the smaller transverse dimension of the guide is parallel with the plane of the ring.
  • the branches are connected to the ring 10 in the electric plane; that is, they branch from a wider side of the ring and the smaller transverse dimension of each branch is parallel with the plane of the ring. This corresponds to a series electrical connection.
  • the ring 10 has a mean circumference equal to wavelengths A within the guide at a selected design frequency f and, therefore, the branches 1 to 6 have a spacing around the ring of A/ 4 between centers.
  • Each of the branches has the same characteristic impedance Z of another embodiment of
  • the wave guide forming the ring 10 has a characteristicimpedance equal to Z /x/f.
  • the branch 6 is terminated in an impedance Z which may, for example, be provided by inserting a block 12 of dissipative material, preferably tapered at its inner end, as shown, to prevent reflection.
  • the hybrid ring just described may, for example, be used to obtain the sum of and ditference between two coherent voltages of frequency f. If the voltages are applied to the arms 2 and 4, a voltage proportional to their complex sum will appear at the arm 3, and a voltage proportional .to their complex difference will appear at the arm 1 and also at the arm 5. However, if the input voltages deviate from the frequency f, the output voltages at the arms 1 and 5 will be oppositely phased and mayv a sort of. first-orderbe combined differentially to provide cancellation of frequency sensitivity, thus increasing the useful frequency band of the network.
  • the path 7 is a series-connected, hollow-pipe wave guide having an effective electrical length of ) ⁇ /4.
  • the required electrical length may be obtained by placingwithin the guide 7 a properly dimensioned core 13 of suitable dielectric material, if necessary.
  • the characteristic impedance of the path 7 is so chosen that the input voltage arriving thereover at the arm 6 will be substantially equal to the voltage arriving at the arm 6 via the ring 10. Due to the half-wave difference between the length of the path 7 and the half-perimeter of the ring 10, these voltages will be 1r radians out of phase with each other and, since they are equal, will tend to cancel, leaving substantially no net voltage on the arm 6.
  • the auxiliary path connecting the arms 3 and 6 is provided by the coupling apertures 19 and 20 which extend through the adjacent walls of the portions 17 and 18.
  • the apertures 19 and 20 are of equal area and are spaced apart a distance equal to 7 ⁇ /4 at the frequency f to constitute a directional coupler of the type disclosed in greater detail, for example, in United States Patent No. 2,562,281, to W. W. Mumford, issued July 31, 1951.
  • the desired compensating voltage is obtained from the arm 3 by means of a directional coupler so that no impedance irregularities will be introduced into the arm.
  • the voltage efiective thereon derived from the arm 3 shall be equal in magnitude to, but 1r radians out of phase with, the voltage at that point derived from the ring 15 by the arm 6, so that these two voltages will cancel each other. This is substantially accomplished by so choosing the areas of the apertures 19* and 20 that these voltages are equal, andby making the length of the arm 6 such that the voltages'will be 1r radians out of phase.
  • the transmission line may be of a different type than wave guide
  • the length of the ring can be other than 3M2
  • some or all of the arms can be connected to the ring in shunt instead of in series. Explicit rules to be followed in making these latter modifications are given in the Tyrrell paper and in my copending application cited above.
  • a network comprising a closed transmission loop having an effective length of wavelengths at a selected design frequency, six transmission branches connected in series with said loop at equally spaced points thereon, a matching termination for one of said branches, and means for substantially preventing the dissipation of power in said termination comprising an auxiliary transmission path connecting said one branch and the branch opposite th re o.
  • a network in accordance with claim 7 in which said apertures are spaced apart a distance equal to a quarter wavelength at said frequency.
  • a network in accordance with claim 9 in which said wave guide is oblong in cross section and the smaller transverse dimension of said guide is parallel with the plane of said loop.
  • each of said branches has a characteristic impedance Z and said loop has a characteristic impedance equal to Z /2.

Description

NOV. 21, 1961 H. T. BUDENBOM 3,010,082
HYBRID RING NETWORK Filed July 25. 1952 m." w n-4.21 a
/N l/E N 7 0/? H 7'. BUDENBOM A 770/? NE V United States Patent 3,010,082 HYBRID RING NETWORK Horace T. Budenbom, Short Hills, N.J., assignor to Bell Telephone Laboratories, Incorporated, New York, N.Y., a corporation of New York Filed July 25, 1952, Ser. No. 300,909 13 Claims. (Cl. 333-9) This invention relates to wave transmission networks and more particularly to hybrid ring networks.
The object of the invention is to improve the impedance match at certain arms of a five-arm hybrid ring.
A more specific object is to make the input impedances equal at all arms of a five-arm hybrid ring without incurring an appreciable loss of power.
A five-arm hybrid ring may be designed to have certain desirable conjugate relationships which may be utilized, for example, in branching arrangements or in networks for obtaining the complex sum of and difference between two coherent input voltages or powers. Rings of this type are disclosed, for example, in the paper by W. A. Tyrrell entitled Hybrid Circuits for Microwaves, published in the Proceedings of the I.R.E. for November 1947, and in my copending United States patent application Serial No. 52,856, filed October 5, 1942, now Patent No. 2,7 84,381 issued March 5, 1957. In one embodiment, such a ring comprises a closed transmission loop having an effective length of wavelengths A at a selected design frequency f and five transmission branches or arms connected in series with the loop at successive points thereon spaced apart by M4 at the frequency For reference, these arms may be designated one to five, with a spacing of M2 between the first and the fifth. The loop and the arms may be constituted by a wave guide, a coaxial cable, or some other suitable type of transmission line. If all of the arms have the same characteristic impedance Z each is terminated in an impedance Z and the loop has a characteristic impedance equal to Z /VZ there will be a good impedance match with the loop for the third arm, but a considerable mismatch for the other arms. In practice, this mismatch has been found to be of the order of three decibels, which is undesirably large for some applications, especially if high power transmission is involved.
In accordance with the present invention, this mismatch is greatly reduced, without substantial power loss, by adding a sixth series arm of characteristic impedance Z connected to the loop at a point midway between the first and the filfth arms, iteratively terminating the added arm, and providing an auxiliary transmission path between the third arm and the sixth arm. The addition of this sixth terminated arm only, without the auxiliary path, will provide an impedance match at the first, second, fourth, and fifth arms, but a considerable fraction of the input power will be lost by dissipation in its termination. The function of the auxiliary path is to prevent this loss of power. In one embodiment, the third and the sixth arms are connected by an auxiliary path extending across the loop and having an electrical length equal to )\/4. If a wave guide of the hollow-pipe type is used, it may be necessary to include dielectric material within the guide to provide the required electrical length. In a second embodiment, the auxiliary path includes a directional coupler connecting the third and the sixth arms.
The nature of the invention and its various objects, features, and advantages will appear more fully in the following detailed description of typical embodiments illustrated in the accompanying drawing, of which FIG. 1 is a perspective View, partly cut away, of one embodiment of a hybrid ring network in accordance with the invention; and
FIG. 2 is a similar view the invention.
The hybrid ring network shown in FIG. 1 comprises a section of transmission line 10 formed into a loop or ring and provided with six equally spaced transmission branches or arms, numbered consecutively 1 to 6, and an auxiliary transmission path 7. As shown, the ring and the branches are made of hollow-pipe wave guide of oblong cross section, adapted to transmit electromagnetic waves having an smaller transverse dimension, as indicated by the arrow 11 in the branch '4. It and branches may also be constituted by coaxial cable or some other suitable type of transmission line. In the ring 10, the smaller transverse dimension of the guide is parallel with the plane of the ring. The branches are connected to the ring 10 in the electric plane; that is, they branch from a wider side of the ring and the smaller transverse dimension of each branch is parallel with the plane of the ring. This corresponds to a series electrical connection. The ring 10 has a mean circumference equal to wavelengths A within the guide at a selected design frequency f and, therefore, the branches 1 to 6 have a spacing around the ring of A/ 4 between centers. Each of the branches has the same characteristic impedance Z of another embodiment of The wave guide forming the ring 10 has a characteristicimpedance equal to Z /x/f. The branch 6 is terminated in an impedance Z which may, for example, be provided by inserting a block 12 of dissipative material, preferably tapered at its inner end, as shown, to prevent reflection.
The hybrid ring just described may, for example, be used to obtain the sum of and ditference between two coherent voltages of frequency f. If the voltages are applied to the arms 2 and 4, a voltage proportional to their complex sum will appear at the arm 3, and a voltage proportional .to their complex difference will appear at the arm 1 and also at the arm 5. However, if the input voltages deviate from the frequency f, the output voltages at the arms 1 and 5 will be oppositely phased and mayv a sort of. first-orderbe combined differentially to provide cancellation of frequency sensitivity, thus increasing the useful frequency band of the network. Even without the auxiliary path 7, if the arms 1 to 6 are all iteratively terminated there will be an impedance match with the ring 10 at each of the branching points, but a considerable part of the input power will be dissipated in the termination 12 of the arm 6.
This power loss is substantially eliminated by connecting the arms 3 and 6 through an auxiliary path 7 extending across the ring 10. As shown, the path 7 is a series-connected, hollow-pipe wave guide having an effective electrical length of )\/4. The required electrical length may be obtained by placingwithin the guide 7 a properly dimensioned core 13 of suitable dielectric material, if necessary. The characteristic impedance of the path 7 is so chosen that the input voltage arriving thereover at the arm 6 will be substantially equal to the voltage arriving at the arm 6 via the ring 10. Due to the half-wave difference between the length of the path 7 and the half-perimeter of the ring 10, these voltages will be 1r radians out of phase with each other and, since they are equal, will tend to cancel, leaving substantially no net voltage on the arm 6. Therefore, only a negligible electric field parallel to the is to be understood that the ring iteratively terminated in a dissipative block 16, corresponding to the termination 12 in FIG. 1. The auxiliary path connecting the arms 3 and 6 is provided by the coupling apertures 19 and 20 which extend through the adjacent walls of the portions 17 and 18. The apertures 19 and 20 are of equal area and are spaced apart a distance equal to 7\/4 at the frequency f to constitute a directional coupler of the type disclosed in greater detail, for example, in United States Patent No. 2,562,281, to W. W. Mumford, issued July 31, 1951. The desired compensating voltage is obtained from the arm 3 by means of a directional coupler so that no impedance irregularities will be introduced into the arm.
In order to prevent loss of input power by dissipation in the termination 16, it is required that the voltage efiective thereon derived from the arm 3 shall be equal in magnitude to, but 1r radians out of phase with, the voltage at that point derived from the ring 15 by the arm 6, so that these two voltages will cancel each other. This is substantially accomplished by so choosing the areas of the apertures 19* and 20 that these voltages are equal, andby making the length of the arm 6 such that the voltages'will be 1r radians out of phase.
It is to' be understood that the above-described arrangements are illustrative of the application of the principles of the invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention. For example, the transmission line may be of a different type than wave guide, the length of the ring can be other than 3M2, and some or all of the arms can be connected to the ring in shunt instead of in series. Explicit rules to be followed in making these latter modifications are given in the Tyrrell paper and in my copending application cited above.
What is claimed is:
1'. A network comprising a closed transmission loop having an effective length of wavelengths at a selected design frequency, six transmission branches connected in series with said loop at equally spaced points thereon, a matching termination for one of said branches, and means for substantially preventing the dissipation of power in said termination comprising an auxiliary transmission path connecting said one branch and the branch opposite th re o.
2. A network in accordance with claim 1 in which said auxiliary path extends across said loop.
3. A network in accordance with claim 2 in which said auxiliary path has a length equal to a quarter wavelength at said frequency.
4. A network in accordance with claim 2 in which said auxiliary path is constituted by a wave guide and said wave guide has a core of dielectric material.
5. A network in accordance with claim 1 in which said auxiliary path includes a directional coupler.
6. A network in accordance with claim 1 in which said one branch has a" portion lying alongside a portion of said opposite branch, and said auxiliary path includes a directional coupler coupling said portions.
7. A network in accordance with claim 6 in which said directional coupler includes two apertures of equal area extending through adjacent walls of said portions.
8. A network in accordance with claim 7 in which said apertures are spaced apart a distance equal to a quarter wavelength at said frequency.
9. A network in accordance with claim 1 in which said loop is constituted by a wave guide.
10. A network in accordance with claim 9 in which said wave guide is oblong in cross section and the smaller transverse dimension of said guide is parallel with the plane of said loop.
11. A network in accordance with claim 1 in which each of said branches has a characteristic impedance Z and said loop has a characteristic impedance equal to Z /2.
12. A network in accordance with claim 1 in which said termination is constituted by a block of dissipative material.
13. A network in accordance with claim 12 in which said block is tapered at its inner end.
References Cited in the file of this patent UNITED STATES PATENTS Ring Mar. 31, 19 53
US300909A 1952-07-25 1952-07-25 Hybrid ring network Expired - Lifetime US3010082A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US300909A US3010082A (en) 1952-07-25 1952-07-25 Hybrid ring network

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US300909A US3010082A (en) 1952-07-25 1952-07-25 Hybrid ring network

Publications (1)

Publication Number Publication Date
US3010082A true US3010082A (en) 1961-11-21

Family

ID=23161115

Family Applications (1)

Application Number Title Priority Date Filing Date
US300909A Expired - Lifetime US3010082A (en) 1952-07-25 1952-07-25 Hybrid ring network

Country Status (1)

Country Link
US (1) US3010082A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3258721A (en) * 1966-06-28 Short position i
US4375622A (en) * 1981-04-20 1983-03-01 Motorola, Inc. Multiport radio frequency signal combiner

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428831A (en) * 1944-08-22 1947-10-14 Rca Corp Radio power division network
US2434646A (en) * 1942-07-30 1948-01-20 Bell Telephone Labor Inc Wave guide branching arrangement
US2496846A (en) * 1947-03-18 1950-02-07 Raytheon Mfg Co Communication system
US2633492A (en) * 1948-12-30 1953-03-31 Bell Telephone Labor Inc Guided wave frequency range, frequency selective and equalizing structure

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2434646A (en) * 1942-07-30 1948-01-20 Bell Telephone Labor Inc Wave guide branching arrangement
US2428831A (en) * 1944-08-22 1947-10-14 Rca Corp Radio power division network
US2496846A (en) * 1947-03-18 1950-02-07 Raytheon Mfg Co Communication system
US2633492A (en) * 1948-12-30 1953-03-31 Bell Telephone Labor Inc Guided wave frequency range, frequency selective and equalizing structure

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3258721A (en) * 1966-06-28 Short position i
US4375622A (en) * 1981-04-20 1983-03-01 Motorola, Inc. Multiport radio frequency signal combiner

Similar Documents

Publication Publication Date Title
US2445895A (en) Coupling arrangement for use in wave transmission systems
Reed et al. A method of analysis of symmetrical four-port networks
US4383227A (en) Suspended microstrip circuit for the propagation of an odd-wave mode
Monteath Coupled transmission lines as symmetrical directional couplers
US5389890A (en) Combiners for R.F. power amplifiers
Ahn et al. Arbitrary termination impedances, arbitrary power division, and small-sized ring hybrids
US2922961A (en) Finline coupler
US2739287A (en) Waveguide hybrid junctions
Laughlin A new impedance-matched wide-band balun and magic tee
US2789271A (en) Hybrid ring coupling arrangement
US2784381A (en) Hybrid ring coupling arrangements
US3904990A (en) N-way power divider with remote isolating resistors
Ahn et al. Toward integrated circuit size reduction
US3184691A (en) Branching hybrid coupler network useful for broadband power-dividing, duplexing and frequency separation
US3422377A (en) Power divider
US2975381A (en) Duplexers
US2666132A (en) Ultrahigh-frequency bridge circuit and apparatus
US2836798A (en) Microwave transmission lines
US7830224B2 (en) Compact Magic-T using microstrip-slotline transitions
Tanaka Ridge-shaped narrow wall directional coupler using te/sub 10/, te/sub 20/, and te/sub 30/modes
US3010082A (en) Hybrid ring network
US2831168A (en) Coupling device for wave transmission systems
US3329884A (en) Frequency multiplier utilizing a hybrid junction to provide isolation between the input and output terminals
US3219949A (en) Multiport hybrid coupling device for wave transmission systems
Saleh Computation of the frequency response of a class of symmetric N‐way power dividers