KR940004592Y1 - Coaxial transmission line and strip line coupler - Google Patents

Abstract

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Description

Coaxial transmission line and strip line coupler

1 is a cross-sectional view of a prior art strip transmission line-to-coaxial transition.

2 is a cross-sectional view of a strip transmission line to coaxial transition in accordance with the principles of the present invention.

3 is an exploded view of a strip transmission line to coaxial transition connector in accordance with the principles of the present invention.

4 is an enlarged cross-sectional view of the coaxial transmission line of the strip transmission line to the coaxial transition connector.

FIG. 5 shows a portion of a cosine curve showing the shape of a coaxial transmission line disposed in a coaxial transmission line to strip transition coupler. FIG.

* Explanation of symbols for main parts of the drawings

50: printed wiring board 52: ground plane

54: lower dielectric layer 56: upper dielectric layer

62: mounting member 64: coaxial transmission line

67 dielectric: 69 internal conductor

70: outer conductor 74: conductor

80: coaxial connector 82: flange

[Technical Field]

The present invention provides a coaxial transmission line for an electromechanical assembly, in particular a strip transmissiol line disposed on the component side of a printed wiring board. It relates to a connector for coupling.

[Design background]

In the electronic device manufacturing industry, printed wiring boards, known as printed circuit boards, are frequently used to mount multiple devices such as hybrid circuits, integrated circuits, individual components, and the like. Printed wiring boards generally have a constant pattern of conductive traces on the surface of the board and act as a dielectric material for electrically coupling the various devices in the desired form. Two or more printed wiring boards may be connected to each other through a connection pad, a connector, and a backplane. The printed wiring can comprise a single dielectric sheet or multiple dielectric sheets stacked together in a slightly rigid laminate. The sheet has a conductive trace or path interconnecting the component pads attached to the plate. A plurality of conducting passages are connected to the connection pads disposed on the plate at or near the edge of the plate for connecting to a circuit disposed outside of the plate. Only one of the four corners can be used for the connection. It is desirable to form these connections at any position anywhere in the plate.

A data processing system transmits or receives a high speed data stream, such as a 2,488 GHz clock signal, having a bit rate that extends into the microwave region at any location on the printed wiring board. There is a growing need for data connectivity at the electro-optic interface of light wave systems. In this case, the conducting trace is designed to run with a controlled impedance transmission line. The controlled impedance transmission line maintains the desired characteristic impedance (eg 50 ohms) in the connection to the frequency extending into the microwave region. Examples of controlled impedance transmission lines are strip transmission lines, microstrip transmission lines, and coplanar waveguide transmission lines.

In one form of assembly, the printed wiring board has a microstrip transmission line attached to one side of the dielectric sheet as a conductive passageway and a relatively wide flat conductor attached to the opposite side of the dielectric sheet. The second dielectric sheet is disposed near the side of the first dielectric sheet having a relatively wide flat conductor and the connector for the coaxial transmission line is coupled to the exposed side of the second dielectric sheet. The exposed side of the second dielectric sheet does not require any conductive passage to be supported. The coaxial connector is coupled to a conductive passage, which may be a trace or strip transmission line located on the side of the wiring board assembly by the opening of the wiring board through which the conductive wiring can pass. One wire extends through the opening of the dielectric sheet from the center lead of the coaxial connector to the conductive trace on the far side of the first dielectric sheet. The second connection is made from the body of the coaxial connector to a conductive pad located on the far side of the first dielectric sheet, and the connector is connected to a relatively wide flat conductor that defines a ground plane located between the two dielectric sheets. The main body is connected.

Conductors passing through the dielectric sheet to connect the coaxial connector to the strip transmission line and the ground plane generate a sudden change in the physical characteristics of the transmission line, thereby causing a sudden change in the characteristic impedance of the transmission line. Therefore, the transmission line loses its controlled impedance performance. This change results in unnecessary electrical performance, resulting in the loss of a signal extending between the strip transmission line and the coaxial transmission line.

An improved coaxial transmission line to strip transmission line coupler is needed to reduce the harmful condition.

Summary of the proposal

According to the principle of the present invention, a coupler coupling a coaxial transmission line to a strip transmission line comprises an inner conductor which is a central conductor having a longitudinal axis, an annular ring of dielectric material disposed around the inner conductor, and concentric Long coaxial transmission lines with external conductors. This coaxial transmission line is coupled to the coaxial transmission line connector at one end. The other end of the coaxial transmission line is attached to the side of the printed wiring board that supports the strip transmission line. The distal end of the inner conductor extending beyond the annular ring of dielectric material is electrically coupled to the strip signal transmission line on the printed wiring board, and the outer conductor, which is an outer conductive member, is electrically coupled to a ground plane coupled to the printed wiring board. .

[details]

Referring to FIG. 1, the prior art is illustrated with a cross-sectional view of a printed circuit board or printed wiring board coupled to a coaxial connector to establish a propagation path between the strip transmission line and the coaxial cable. Coaxial cables can transmit signals that can extend into the microwave region. It can be seen that there are no significant differences in the transition from the strip transmission line to the coaxial transmission line and the transition from the coaxial transmission line to the strip transmission, ie these members are identical.

The printed circuit board or printed wiring board 10 has a ground glane 12 disposed between the lower dielectric layer 14 and the upper dielectric layer 16. A strip transmission line 18 for establishing a conductive passage between the components is attached to or consists of a portion of this plate 10 at a discontinuous position on the outer surface 20 of the lower dielectric layer 14. .

At a predetermined position on the wiring board 10, a cutout 21 for the coaxial connector 22 is provided. This opening 21 is arranged in proximity to the portion of the strip transmission line 18 to be coupled to the coaxial connector 22. Ground plane 12 is coupled to a conductive trace 24 that provides a conductive passage from the ground plane 12 to the bottom surface of lower dielectric layer 14 and the top surface of upper dielectric layer 16.

Conductive trace 24 provides an electrical connection between ground plane 12 and flange 28 of coaxial connector 22.

Coaxial connector 22 is disposed on top of upper dielectric layer 16 and resides on opening 21 such that central conductor 27 of coaxial connector 22 extends through opening 21. In FIG. 1, the coaxial connector 22 is a flanged bag of the type manufactured by M / A-Com Omni Spectra, Inc., Merrimark, New Hampshire. It may be a back receptacle.

The coaxial connector 22 has a flange 28, which has four mounting openings 30 tapered to accommodate a suitable size round machine screw 34. The opening 30 in the flange 28 is aligned with the four openings 32 arranged in the wiring board 10. Four small screws 34 located in the opening 32 are screwed into the opening 30 in the flange 28 to securely fix the coaxial connector 22 to the wiring board 10.

The opening 32 is positioned to avoid interference with the strip transmission line 18 disposed on the bottom surface of the dielectric layer 14, while the ground plane 12 is directly and through a small screw 34 through the opening 32. It is installed so as to contact the flange 28 via). It can also be seen that the coaxial connector 22 is mounted on the side of the wiring board 10 that does not support the strip transmission line 18.

The center conductor 27 of the coaxial connector 22 protrudes through the opening 21 and extends beyond the lower surface of the dielectric layer 14.

In order to establish the conduction passage, the end of the center conductor 27 is properly bent to contact the strip transmission line 18 and a permanent connection can be made between the conductor 27 and the conducting trace 18 by soldering.

Sudden changes in shape from the coaxial shape of the coaxial connector 22 to the strip transmission line 18 with the ground plane 12 create discontinuities that have a detrimental effect on the propagation of high frequency energy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, an embodiment of the present invention with reference to FIG. 2 is a cross-sectional view of a structure according to the principles of the present invention for reducing the unnecessary effort of coupling a strip transmission line to a coaxial transmission line conductor via a connector of the prior art. Shows.

As shown in FIG. 1, a printed wiring board 50 includes a ground plane 52 positioned between the lower dielectric layer 54 and the upper dielectric layer 56. Conductive traces 58 such as microstrips, transmission lines, coplanar waveguide transmission line patterns, or strip transmission lines are used to establish controlled impedance conduction paths between the components. It is supported on the outer upper surface 57 of the 56.

Clearance cutouts 59 are provided for machine screws 60 at predetermined positions on the wiring conduit 50. The clearance opening 59 is positioned on the top surface 57 of the upper dielectric layer 56 to avoid interference with the strip transmission line 58. The ground plane 52 can be made concave from the opening 59 to prevent the ground plane from contacting the small screw 60, or the ground plane can be recessed through the small screw 60 so that the ground plane can be mounted with a mounting member ( It may come up to the edge of the opening 59 to allow contact with 62).

Mounting member 62, which may be made of conductive material or non-conductive material, is secured to the top surface of upper dielectric layer 56 by a small screw 60 that is screwed into member 62 through opening 59. If desired, screws 60 may be replaced with mounting pins that may be soldered to the conductive passages on the bottom surface of dielectric layer 54.

Mounting member 62 supports coaxial transmission line 64 and coaxial connector 80. Coaxial transmission line 64 may be semirigid or flexible, and a cosine wave extending from 0 ° to 180 ° as shown in FIG. 5, for example, a trace of a portion of the cosine wave. It is possible to have a shape that can be characterized by a similar trace of the part.

At the lower end 66 of the coaxial transmission line 64, the outer conductor 70 and the dielectric 67, which are outer conductive members, are removed to expose the lower end 68 of the central conductor 69, which is the inner conductor. The lower end 68 of the center conductor 69 slightly protrudes from the end of the dielectric 67 and extends beyond the top surface of the strip transmission line 58 when positioned on the printed wiring board. Good contact between the end 68 of the center conductor 69 and the strip transmission line 58 can be provided by soldering these two members to each other.

The opening 72 of the upper dielectric layer 56 provides a passage for the conductor 74 to connect the ground plane 52 to the conductive pad 76 disposed on the surface 57 of the upper dielectric layer 56. Conductive pad 76 may be positioned to contact external conductive member 70. If desired, the outer conductive member 70 can be soldered to the conductive pad 76 to provide good electrical contact. In the case where the member 62 is made of a conductive material such as brass, bronze, aluminum, or copper, it is preferable that a conductive pad 76 is positioned between the member 62 and the upper dielectric layer 56, and soldering is required. none. In addition, if the member 62 is conductive, it is preferred that the member 62 is allowed to become a conductive member 70, and the outer conductive member 70 of the coaxial transmission line 64 can be removed. If the member 62 is made of a non-conductive material, its surface is not treated to be conductive, such as plating, and requires a separate outer conductive member 70 of the coaxial transmission line.

The upper terminal end 78 of the coaxial transmission line 64 is a standard bulkhead type such as Model 9954-0081-6220 manufactured by Dynawave Inc. of Georgetown, Massachusetts. May be coupled to the connector 80.

This connector 80 can be fixed to the side of the mounting member 62 by a small screw 81. The center conductor 100 of the connector 80 has an inner diameter that fits into the center conductor 69 of the coaxial transmission line 64 as a metal tube. The outer conductor 70 of the coaxial transmission line 64 is located between the mounting member 62 and the flange 82 of the bulkhead connector 80, and the body of the bulkhead connector 80 and the coaxial transmission line ( It is possible to provide good electrical connection between the outer conductive member 70 of 64.

Referring to FIG. 3, an exploded view of the strip transmission line and the coaxial transmission line connector is shown. In this embodiment, the mounting member 62 is made of brass and the coaxial transmission line 96 is semi-rigid, while the mounting member 62 may be made of other material and the coaxial transmission line 96 is flexible. If the mounting member 62 is conductive, the outer conductor of the coaxial transmission line 96 can be removed.

Further, the conductive trace or line 91 may be in the shape of a micro strip transmission line, a resonance waveguide transmission line or a strip transmission line. In this embodiment, the firewood member 62 may be formed of two members, namely the lower member 90 and the upper member 92. The lower member 90 supports the slot 94 and houses a radial coaxial transmission line 96 that is bent in a partial cosine shape that is shaped as shown in FIG. 5 in this embodiment.

Coaxial transmission line 96, shown in more detail in FIG. 4, fits into slot 94. The upper member 92 fits over the lower member 90 and has a slot 97 that is sized to receive the upper portion of the coaxial transmission line 96. The small screw 98 that is screwed into the lower member 90 through the upper member 92 secures the lower member 90 to the upper member 92 and the coaxial line 96 in a captive manner. Keep it.

The center sleeve conductor 100 of the bulkhead connector 101 is slidably coupled to the protruding center end 102 of the coaxial transmission line 96, and the connect 101 is connected to the upper and lower members by means of small screws. 90, 92). The small screw can penetrate the clearance opening 59 of the printed wiring board, but is screwed into the assembled mounting member 62 and secures the mounting member to the printed wiring board.

The connector described in the present invention is mounted on the side of the printed wiring board that supports the strip transmission line. This is the complete opposite of the prior art connectors which are not mounted on the side of the printed wiring board supporting the strip transmission line. In the present invention, prior to assembly, a portion of the lower end of the outer conductor and a portion of the dielectric of the coaxial transmission line are removed to expose the center conductor 104 as shown in FIG. The drawing transmission line 96 is located in the groove 94 of the lower member 90, and the lower member 90 is mounted on the printed wiring board by mounting screws. The exposed end of the center conductor 104 extending slightly beyond the end of the outer conductor lies on top of the associated strip transmission line 64 and can be soldered to the strip transmission line 64 to provide a good electrical path. The outer conductor of the coaxial transmission line 96 may be soldered to the pad 76 disposed on the top surface of the printed wiring board and coupled to the ground plane 52. The impedance of the strip transmission line 96 can be designed to match the impedance of the coaxial transmission line 96, which is typically 50 ohms, to provide optimal transmission conditions. Next, the upper member 92 of the mounting member 62 is assembled on the lower member 90 to fix the coaxial transmission line 96 in place and provide a protective cover on its connection.

Upper and lower members 92 and 90 provide mounting holes for the bulkhead connector 80. The center conductor 100 of this bulkhead connector 80 is slidably coupled to the protruding center conductor 102 of the coaxial transmission line 96, and the connector 101 is attached to the mounting member 62 by a small screw. Is fixed to.

In this embodiment, the coaxial transmission line and the strip line coupler are shown with a printed wiring board, which has a strip transmission line on one side of the dielectric plate and a ground plane on the viewing side of the dielectric plate. In the case where the conductive passage or trace of the printed wiring board is a transmission line in the form of a coplanar waveguide, both the strip signal conductor and the ground plane conductor are both on the common surface of the dielectric sheet and separated by a fixed gap. These two conductive traces on the same side of the printed wiring board are wired to contact the appropriate portions of the coupler. Thus, the conductive trace coupled to the signal is positioned to contact the center conductor 68 of the coupler, and the conductive trace coupled to the ground plane is associated with either the outer conductive member 70 or the mounting member 62. Even if they are positioned to contact them.

Claims (4)

An annular ring 67 of dielectric material disposed around the inner conductor and an outer conductive member 70 disposed around the dielectric material, the strip signal conductor of the sheet of dielectric material in the middle of the sheet edge of the dielectric material In a coupler for coupling a coaxial transmission line to a controlled impedance strip transmission line coupled to the side, the sheet of dielectric material supporting strip signal conductors 58 on one side and ground plane on the other side. The longitudinal axis of the first end of the inner conductor forms an obtuse angle with the longitudinal axis of the inner conductor, the first end of the inner conductor protrudes past the annular ring of dielectric material such that the coupler is a strip of the sheet of dielectric material. The on the sheet of dielectric material in the middle of the edge of the sheet of dielectric material when coupled to the signal conductor side. And tangentially aligned and coupled to the strip signal conductor (58), wherein the outer conductive member is coupled to a ground plane on a sheet of dielectric material. 2. The apparatus of claim 1, wherein the outer conductor comprises a mounting member of a conductor coupled to the coaxial transmission line receiving means and coupled to a second end of the inner conductor, the mounting member being connected to the strip signal conductor side of the sheet of dielectric material. Coupler characterized in that coupled. The first end of the inner conductor of claim 1, wherein the mounting member of the non-conductive material is coupled to the coaxial transmission line receiving means, the mounting member being coupled to and separated from the side of the sheet of dielectric material supporting the signal conductor. Coupler comprising two coupling members to expose the. 2. The annular ring of dielectric material adjacent to the first end of the inner conductor further comprises the annular ring on top of the strip signal on the sheet of dielectric material when the mounting member is coupled to the strip signal conductor side of the sheet of dielectric material. And a flat surface for positioning the first end of the inner conductor.