US2402624A - Phase changer - Google Patents

Description

L. HlMMEL PHASE CHANGER June 25, 1946.

2 Sheets-Sheet 1 Filed. Jan. 8, 1943 mmvron. LEON HIMMEL Patented June 25, 1946 UNITED STATES PATENT OFFICE PHASE CHANGER Application January 3, 1943, Serial No. 471,767

15 Claims. 1

Thisinvention relates to improvements in phase changers, and more particularly to a device for changing phase in a" high frequency transmission line.

An object of this invention is to provide a truly aperiodic" phase" changer for use with high frequency transmission lines.

A further object of this invention is the provision of a phase changer operating on a section of a transmission whose characteristic impedance is always matched tothat of the main transmission l'ine; while the wave propagation velocity may be varied at will.

A still further object of this invention is the provision of aphase changer which is operated by the insertion of a movable member between two'conduct'ors of a high frequency transmission line section, this member being so designed as to provide a constant L/C transmission line ratio and a variable LCtransmission line product depending upon its position, whereby the wave propagation velocity of the transmission line may be varied in accordance with the position of the member; while its characteristic impedance will be" maintained constant.

Still-another object of this invention is to providea phase changer operating in the manner above described without necessitating the use of any'sli dable or otherwise relatively movable contacts.

Other objects and advantages of the present invention will appearf'rom the 'following detailed description of a preferred embodiment and' modifi'cation thereof, illustrated in' the accompanying drawings; in which:

Fig. 1 is-a verticalplan view, partially broken away, of an improved phase changer in accordance with the present invention;

Fig; 2 is a vertical section'takenalong the line 2-'-2 of Fig. 1-;

Fig. 3 is a transverse section taken along the line;3''3 ofFig. I;

Fig. 4 is a transverse section taken along'the line44'of Fig. 1; V

Fig. 5 is a plan view' illustrating the manner in which the transmission line section of the phase changer is interconnected with the rest of the transmission linewhosephase is to be controlled; and

Fig. 6 is a vertical cross-sectional view of a modified phase changer control member.

As more particularly'shown in Figs. 1, 2 and 3, the phase changer in accordance with the present invention is preferably mounted in a generally extending conductor bars 40 and. 40'.

of a rear panel [0 having vertically extending bent-over strengthening sections l2 on either side andintegral forwardly extending top and bottom sections Hand M. The top and bottom sections I4, I4 are preferably turned inwardly at their forward ends to form respective transverse fianges l6. IS. The top and bottom transverse fianges l6, l6 are interconnected by vertically extending angle irons I8 and IS on opposite sides of the framework by' means of suitable corner angles [9 attached to the vertical angle irons and the turned over flanges l6, I6 in any suitable manner, as by welding. A series of mounting lugs 20 will be' attached to the rear panel In to permit mounting of the phase changer unit in a suitable control rack. A transverse sheet metal member 22 is connected across the vertical angle irons l8 and I8 through suitable means such as screws 24'. The transverse member' 22 serves to strengthen the framework and also acts as a mounting for a suitable indicator to be described in more detail hereinafter. The front and sides of the phase changer may be enclosed by a removable cover 26 to provide a completely enclosed dust-proof unit.

At both the top and bottom of the framework and within the same are provided a pair of generally U-shaped supports 28, each having spaced apart inwardly extending legs 30' and an extended base 32 connected to the top and bottom sections of the frame by suitable means such as bolts 34. Between each of the arms 30 is mounted an insulating block 36, being firmly attached between the legs by means such as through bolts 38. The insulating blocks 36 are attached to receive and support in spaced parallel relationship vertically The conductor bars 40 and 40 are preferably T-shapecl with the leg of the T' projecting into the supporting insulating blocks and the tops of the Ts being opposed to one another in parallel spaced relationship. The conductor .bars 40 and 40 and, more particularly, their legs inserted in the insulating blocks 36 are held in place by the use of suitable clamping bolts 42 and 42'.

A control member 44 is positioned between the conductor bars 40 and 40' for varying wave propagation velocity along the conductor bars in accordance with its relative position between these bars. The control member 44 extends vertically substantially the length of the conductor bars and, as is most clearly shown in Fig. 3 is preferably formed of a metal section 46 rigidly connected as a unit to a dielectric section 48. The

3 dielectric section 43 is solid at one end, being provided with a pair of forwardly extending legs 50 between which a reduced portion 52 of the metal section 46 is inserted. Legs 50 of the dielecric section are interconnected with the reduced portion 52 of the metal section by suitable means to such as screws 54 to form, in effect, an integrally combined metal and dielectric control unit. In the form of control unit illustrated, the main part of the metal section 46 is made hollow, the small section 52 thereof being formed as integrally continuous legs of the hollow member. While this construction is not necessary for the purposes of the present invention, it provides a saving of metal over a solid metal section and is the electrical equivalent of the latter. The top and bottom of the hollow metal section 42 are closed by metal blocks 56, rigidly attached within the metal section in any suitable manner as by soldering orbrazing, the blocks 55 serving as partial supports for metal end members 58 and 50'. These metal end members are attached to the control member 44 in any suitable manner and are provided with threaded through openings receiving threaded shafts 60 and 60. The shaft 60 is sufliciently long to extend through and outside of the cover 26 and on this outer end there is attached a suitable crank 62. A Vertically extending shaft 64 interconnects the threaded shafts 60 and 60' by means such as bevelled gear pairs 66 and 68. The front end of the shaft 60 and the upper end of the shaft 64 are journalled in a suitably designed support I which may be, in turn, connected to top I4 of the framework while the front end of the shaft60 and the lower end of the shaft 64 are journalled in a comparable bearing member 12 connected to the bottom I4 ofthe framework. The rear end of the shaft 60 may be journalled in a member I4 which may also serve as a strengthening bracket between the rear panel I0 and the bottom I4 of the framework, while a similar member I0 connected between the rear, panel I0 and the top I4 of theframework serves to support the rear of the threaded shaft 60.

It will be clear to those skilled in this art from the foregoing description that rotation of the crank 62 rotating, as it does, the threaded shaft 62 and, through the vertical shaft 64, the threaded shaft 60', will result in an in and out movement of the control member 44, depending upon the direction of rotation, between the conductor bars 40 and 40'.

The conductor bars 40 and 40' are preferably a section of a transmission line which may include spaced apart conductors I8 leadinginto the phase changer and the spaced apart conductors 18' from the phase changer. Connection between the conductors of the transmission line and the conductor bars of the phase changer forming a transmission line section, is preferably brought about in a manner such as shown in more detail in Fig. 4. As there illustrated, the conductors I8 are inserted into openings in small metal blocks 80 and 80 and rigidly attached thereto as by soldering. At the extreme ends of the conductor bars 40 and 40', on the other hand, are rigidly connected, also as by soldering, small similar metal blocks 82 and 82.- The actual electrical connection between the conductors I8 and the conductor bars 40 and 40' is then accomplished by attaching the block to the block 82 and the 4 tion which is both mechanically strong and of low electrical resistance.

The input transmission line conductors 18 are, as is usual, positioned within a suitable shield 86, while the output transmission line conductors "I8 are positioned within a suitable shield 88 which, if it is desired to have both the input to and the output from the phase changer positioned at the same end, will run through the phase changer, as illustrated. The output transmission line conductors I8 will be connected to the lower end of the conductor bars 40 and 40' in the manner described above in connection with Fig. 4 and will pass through a suitable external connector, which may be of the type indicated at 90 in Figs. 1 and 2. The conductors of the transmission line will be properly positioned within their respective surrounding shield by means such as insulating disks 92.

In order that the relative position of the control member 44 between the conductor bars 40 and 40' may be indicated, the phase changer may be provided with a suitable scale 94 cooperating with a movable indicator arm 96. The scale 94 may be formed on the front face of a generally U-shaped member 98, the legs of which are connected to the transverse member 22, previously described, as by screws I00. The forward end of the indicator arm 96 will project through a suitable opening in the front of the U-shaped member 98, along which opening the scale 94 may be positioned, while the rear of the indicator arm 90 is inserted into a member I02 pivotally supported relatively to the member 22 by suitable means such as brackets I04. Rotatable as a unit with the member I02, is a generally inwardly and downwardly extending arm I06 whose lower end is pivotally interconnected with a link I08 which, in turn, is pivotally attached to a support I I0. The latter is fastened to the front vertical face of the control member 44 by suitable,

means such as screws II2. It will be at once clear that movement of the control member 44 will be transmitted through link I00 and the arm I06 to the indicator 96 so that the position of the latter will give an, indication of the relalive position of the control member 44.

The phase changer which hasbeen described above in more detail fulfills the objects and realiZes the advantages of the invention. The control member 44 is so designed and proportioned that a change in phase or a change in the wave I mission line to be controlled. Spacing the conductor bars 40 and 40' further apart will'immediately increase the inductance, and decrease the capacitance of this transmission line section and will thus increase the characteristic impedance of that section. As a result, the transmission line section comprising the conductor bars 40, 40' would not be matched to the rest of the transmission line. However, by the insertion ofthe control member, for example, the metal section 46 thereof, the effective inductance which was increased by separating the conductor bars could be reduced to its original value, the, capacitance is increased and the transmission line section of the phase changer will be again matched to the rest of. the transmission line. Now, for. example, it the control. member 414 is so moved. that the dielectricsection 48iispositioned between the conductor bars 410- and 40 the surge impedance of the transmission line section of the phase changer may be maintained at the same value as when the metal section 46 was'between the conductor bars provided that the L/C ratio. of this transmission line section. is maintained constant. A proper proportioning of the dielectric section 48, characteristic of the control member in accordance with this-inventioncan effect this result. The dielectric section 4% is so designed that although metal has been removed from between the conductor bars 40 and 40', thusraising the value of L, the dielectric constant of the dielectric section 4 8. is such that C has been raised an equal proportional value. so that the ratio of L/C remains constant and thus the characteristic impedance of the transmission line section has not been altered. On the other hand, the wave propaga tion velocity'is inversely proportional tothe prodnot. of. L C and since both L and C are now larger, as compared to the conditions when the metal section 46- was between. the conductor bars the wave propagation velocity and thus the phase has been changed. The section of the control member. 44 which includes the reduced metal section. 52 and the dielectric legs Ellis so designed to give an intermediate value of. wave propagation velocity, butstill so proportioned that the characteristic impedance or the L/C ratio remains constant. At the same time, it will be noted that no sliding or otherwise relatively movable contacts are necessitated by the present invention. Hence there will be no poor contact due tocorrosion of surfaces.

The control member 44 may be constructed in various ways so long as the essential characteristics of the present invention are maintained. For example, the control member may have a shape such as exemplified by the control member 244 of Fig. 6. Instead of the stepped configuration illustrated in the preferred embodiment, the control member 244 provides a more gradual change in phase by using a wedge-shaped metal section 246 enclosed on either side by oppositely directed wedge-shaped dielectric sections 248 and 248'. The parts may be connected together to form an integral unit by means such as screws 254. The manner of operation of the control member 244 will be identical with the principleof operation of the control member 44, provided that the metal and dielectric sections are so proportioned that the L/ C ratio of the transmission line section of the phase changer is maintained constant while, as in the manner previously explained, the L C product will vary, It is contemplated that other configurations of metal and dielectric control member units having the desired characteristics may be formed as will occur to those skilled in this art.

While, for the sake of clarity, I have described in some detail a specific embodiment and modification of phase changer unit embodying the principles of my invention, it is to be clearly understood that the invention is not to be considered as limited to the specific structural features shown and described, but that various changes can be made without departing from the spirit and scope of the invention as outlined in the objects thereof and embodied in the claims that follow.

What is claimed is:

1. A phaser comprising, in combination, a

6. transmission line section having a pair of parallel spaced apart conductors, and a member transversely movable: between said conductors and extending substantially the length of said. transmission line section, said member consisting. of a metal section at one transverse end, a dielectric section at its other transverse end, and combined metallic and dielectric sections intermediate its transverse ends, the width of the dielectricsection and of the intermediate metallic and dielectric sections. being greater than. the width of the metallic section alone in such auproportion' that the L/C ratio of the line remains constant; no matter which portion of said member is positioned between said conductors, and means. for moving said member transversely between said conductors so as to position diflerent sections thereofv intermediate said conductors for varying the velocity of wave propagation along said conductors while maintaining said transmission line section constant.

2.. The combination according to claim 1, in which said member consists of a metal section at one end having a predetermined width. for a portion of its length and a smaller predeterminedwidth for another portion of its length, a first dielectric section at the other end havinga predetermined width for a portion of its length and a smaller dielectric section extending on opposite sides of said reduced metal section in the direction of said conductors.

3. A combination according to claim 1, in which said. member consists of a metal-section decreasing in. width from one end of said member to the other, and a pair of dielectric sections increasing inwidth from the one end of the member to the other, attached tothe opposite lateral faces of said metal section.

4. The combination according to claim 1, in combination with means for indicating the relative position of said member between said conductors.

5. A phase changing unit comprising a transmission line section having a pair of spaced apart substantially parallel conductors, and a metal and dielectric means transversely movable between said conductors for varying the inductance and capacitance of the transmission line in equal proportion so that the L/ C ratio of the surge impedance of the line remains constant, while the velocity of wave propagation is varied in accordance with the position of such means between the conductors.

6. The combination according to claim 5, in which said means comprises a member consisting of varying overlapping metal and dielectric sections, the metal section having its greatest diameter at one end of said member in the direction of movement thereof, and the dielectric section having its greatest dimension at the other end of said member.

7. The combination according to claim 5, in which the said means comprises a member consisting of a. metal section at one end having a predetermined width for a portion of its length and a smaller predetermined width for another portion of its length, a first dielectric section at the other end having a predetermined width for a portion of its length, and a small dielectric section extending on opposite sides of said reduced metal section in the direction of said conductors.

8. The combination according to claim 5, in which said means comprises a. member consisting of a metal section decreasing in width from one 7v end of said member to the other, and a pair of dielectric sections increasing in width from one end of the member to the other attached to the opposite lateral faces of said metalsection. V

9. A phase changing unit, comprising, in combination, a supporting framework, a pair of spaced apart and co-planar conductor bars extending longitudinally Within said. framework, insulating means for and supporting said pairs in said framework, a control membervpositioned between said conductor. bars, said control members having a length substantially equal to the length of said bars, a depth substantially greater than, the thickness of said bars, and a width of variable cross section, said control member be-' ing formed as a unit consisting of a metal portion of relatively small cross section, decreasing to a still smaller cross section, and a dielectric portion having a relatively large cross section decreasing to a smaller cross section overlapping the smaller cross section of the metal portion, and means supported by said framework for moving said control member transversely between said bars for inserting different cross sections of said member directly between said bars.

10. The combination according to claim 9, in combination with means supported by said framework for indicating the position of said control member between said bars.

11. The combination according to claim 9, in combination with threaded end pieces attached to opposite ends of said control member, and in which said moving means includes threaded shafts engaging said threaded end pieces, a longitudinally extending shaft, gears interconnecting said longitudinal shaft with both of said threaded shafts, and a crank on one of said threaded shafts.

12. The combination according to claim 9, in which the metal portion of said control member continually gradually decreases in cross, section and the dielectric portion .is formed'as two sec! tions on opposite sides of the metalportion, each section continually gradually decreasing in cross section from the smaller to the larger part of the metal portion. a v

13. The combination according to claim,9, in which the metal portion of said control member decreases in cross section in step-by-step fashion and the dielectric portion decreases in cross section in step-by-step fashion, the smallest cross sectional sectionof the dielectric portion being split and positioned on opposite sides of the smallest metal section. V V

14. The combination according to claim 9, in combination with metal blocks internally rigidly attached to the end of each conductor bar, and conductor-receiving blocks having conductor-receiving openings removably attached to said metal blocks between the conductor bars, the distance between the conductor-receivingopenings in the conductor-receiving blocks at each end being substantially less than the distance between the corresponding conductor bars to which they are attached by said metal blocks.

15. In combination, a transmissionline having a pair of spaced conductors providing a predetermined characteristic impedance, a section of said transmission line having a. pair of more widely. spaced conductors providing a greater characteristic impedance, and a metal and dielectric means positioned between the said Widely spaced conductors to reduce the characteristic impedance of said section to that of the rest of the transmission line, said means including means for varying the velocity of wave propagation alongvthe line.

LEON HIMMEL.

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