High frequency signal line

BACKGROUND OF THE INVENTION

Field of the Invention

0001This invention relates to a high frequency signal line adapted to be selectively used as open type (leakage) or as closed type (transmission).

Description of the Related Art

0002The high frequency signal line of well known art typically comprises the central conductor of the coaxial caboe, the cylindrical outer conductor partially formed with the longitudinal opening and containing therein said central conductor, the shielding covers arranged along said longitudinal opening and adapted to be detachably attached to said opening, the directional coupling conductor for high frequency coupling disposed within at least one of said shielding covers so as to extend in parallel to said central conductor, the matching resistor connected to one end of said directional coupling conductor, and the branch line connected to the other end of said directional coupling conductor. The space defined between the central conductor and the outer conductor is filled with the insulator (Japanese Patent No. 2579583).

0003As will be apparent from the foregoing description, the high frequency signal line of well known art has usually adopted a simple construction in which the shielding cover is mounted above the opening of the outer conductor. Such simple construction has often made it difficult to fix the shielding cover and inevitably accompanied with an apprehension that the outer conductor might come in contact with the directional coupling conductor extending within the shielding cover. In addition, a strength of the branched output has necessarily depended on a length of the induction line and, to adjust a strength of the output, it has been required for the high frequency signal of well known art to prepare the induction lines of different lengths. Consequently, it has been also required to prepare the shielding covers of different lengths.

SUMMARY OF THE INVENTION

0004In view of the problems as have been described above, it is a principal object of the invention to provide a novel high frequency signal line not only adapted to eliminate an apprehension that the outer conductor and the directional coupling conductor might come in contact with each other and cause any malfunction but also adapted to facilitate a strength of branched output or leakage field to be adjusted depending on the particular requirement of operation.

0005The object set forth above is achieved, according to one aspect of the invention, by a high frequency signal line comprising a transmission line consisting of a central conductor and a cylindrical outer conductor formed with a longitudinal opening, said transmission being covered with a cylindrical shielding shutter formed with a longitudinal opening, on one hand, and an induction line consisting of a trough-shaped shielding cover formed with a longitudinal opening and adapted to be detachably attached to said shielding shutter and a directional coupling conductor for high frequency coupling which extends within said shielding cover in parallel to said central conductor, on the other hand.

0006The object set forth above is achieved, according to another aspect of the invention, by a high frequency signal line comprising a transmission line consisting of a central conductor and a cylindrical outer conductor formed with a longitudinal opening, said transmission line being covered with a cylindrical shielding shutter formed with a longitudinal opening, and an induction line consisting of a shielding cover adapted to be detachably fastened under an interlocking effect to said outer conductor and a directional coupling conductor for high frequency coupling which extends within said shielding cover in parallel to said central conductor.

0007The object set forth above is achieved, according to still another aspect of the invention, by a high frequency signal line comprising a transmission line consisting of a central conductor and a cylindrical outer conductor formed with a longitudinal opening and said transmission line is covered with a cylindrical shielding shutter formed with a longitudinal opening so that the opening of said transmission line can be adjustably widened or restricted.

0008The object set forth above is achieved, according to further another aspect of the invention, by a high frequency signal line comprising a transmission line consisting of a central conductor and a cylindrical outer conductor formed with a longitudinal opening and said transmission line is covered with a cylindrical shielding shutter partially formed with a spiral opening.

0009The object set forth above is achieved, according to an additional aspect of the invention, by a high frequency signal line comprising a transmission line consisting of a central conductor and a cylindrical outer conductor formed with a spiral opening and said transmission line is covered with a shielding shutter partially formed with a longitudinal opening.

0010The object set forth above is achieved, according to still another additional aspect of the invention, by a high frequency signal line comprising a transmission line consisting of a central conductor and a cylindrical outer conductor formed with a longitudinal opening, said outer conductor being provided on opposite sides defining said opening with a pair of rail supporting wings, respectively, on which rails are laid in parallel to said outer conductor, on one hand, and an induction line consisting of a shielding cover provided with wheels by which said shielding cover can move along said rails and a directional coupling conductor for high frequency coupling which extends within said shielding cover in parallel to said central conductor, on the other hand.

0011It is also possible without departing from the scope of the invention to cover said transmission line with the cylindrical shielding shutter formed with a longitudinal opening.

0012It is also possible without departing from the scope of the invention to provide said rail supporting wings integrally with said outer conductor or said shielding shutter.

BRIEF DESCRIPTION OF THE DRAWINGS

0013<ul id="ul0001" list-style="none"><li>Fig. 1 is a perspective view showing a first embodiment of the high frequency signal line according to the invention;</li><li>Fig. 2 is a sectional view showing the first embodiment as on a first step of operation;</li><li>Fig. 3 is a view similar to Fig. 2 showing the first embodiment as on a second step of operation;</li><li>Fig. 4 is a view similar to Fig. 2 showing the first embodiment as on a third step of operation;</li><li>Fig. 5 is a perspective view showing a second embodiment of the high frequency signal line according to the invention;</li><li>Fig. 6 is a sectional view showing the second embodiment;</li><li>Fig. 7 is a perspective view showing a third embodiment of the high frequency signal line according to the invention;</li><li>Fig. 8 is a view similar to Fig. 7 showing a fourth embodiment of the high frequency signal line according to the invention;</li><li>Fig. 9 is a view similar to Fig. 7 showing a fifth embodiment of the high frequency signal line according to the invention; and</li><li>Fig. 10 is a sectional view showing the fifth embodiment.</li></ul>

DETAILED DESCRIPTION OF THE EMBODIMENTS

0014Details of the invention will be more fully understood from the description of preferred embodiments given hereunder in reference with the accompanying drawings.

0015Fig. 1 is a perspective view showing a first embodiment and Figs. 2 through 4 are sectional side views illustrate a manner in which the first embodiment operates. According to the first embodiment, a high frequency signal line consists of a transmission line 10 and an induction line 20. The transmission line 10 comprises a central conductor 11 and a cylindrical outer conductor 12 having its peripheral wall interrupted along a longitudinal opening. Said outer conductor 12 making a part of said transmission line 10 is covered with a shielding shutter 13 which has also a longitudinal opening and is in close contact with said outer conductor 12. The shielding shutter 13 is adapted to be rotated closely around said outer conductor 13. The opening of the outer conductor 12 is dimensioned to be slightly narrower than the opening of the shielding shutter 13 so that the opening of said outer conductor 13 is fully exposed when said outer conductor 13 is at its fully uncovered position. Along each of opposite side edges defining therebetween said opening of the shielding shutter 13, there are provided a series of holes 14, 14, ... at regular intervals so as to receive the corresponding pins formed on a shielding cover 22 as will be described later and thereby to fasten said shielding cover 22 to said shielding shutter 13.

0016The induction line 20 comprises said shielding cover 22 which is shaped like a trough having its opening extending longitudinally of said line 20 and a directionally coupling conductor 21 extending within said shielding cover 22 in parallel to central conductor 11 for high frequency coupling. Said shielding cover 22 is adapted to be detachably attached to said shielding shutter 13 with said opening of said shielding cover 22 opposed to said opening of said shielding shutter 13. This induction line 20 is adapted to be connected by a connector 23 provided on an end of said directionally coupling conductor 21 to a branch circuit (not shown). Along each of opposite side edges defining said opening of said shielding cover 22, there are provided a series of pins 24, 24, ... adapted to be inserted into the corresponding holes 14, 14, ... of said shielding shutter 13 so as to fasten said shielding cover 22 to said shielding shutter 13.

0017From the state shown by Fig. 1, the shielding shutter 13 can be rotated together with the induction line 20, as seen in Figs. 2 through 4. Fig. 2 is a sectional view illustrating a normal state in which the high frequency signal line can operate. First, the pins 24, 24, ... of the shielding cover 22 are fitted into the corresponding holes 14, 14, ... of the shielding shutter 13. Thereupon the outer conductor 12 occupies its fully opened position at which a signal coupling can be achieved at the maximum input/output.

0018Fig. 3 is a sectional view illustrating the shielding shutter 13 in the first embodiment as said shielding shutter 13 has been slightly rotated from its position in Fig. 2. As will be apparent from Fig. 2, the directional coupling conductor 21 lies outside the outer conductor 12 and therefore no physical contact can occur between these two components. Thus, a signal output from the central conductor 11 can be coupled to the directional coupling conductor 21 without apprehension that said physical contact might interfere the desired signal coupling.

0019Fig. 4 is a view similar to Fig. 3 illustrating the outer conductor 12 in the first embodiment as it has been completely closed by the shielding shutter 13. In this state, the signal output from the central conductor 11 can no more coupled to the directional coupling conductor 21.

0020The outer conductor 12 maybe adjustably opened or closed in the manner as has been described above to adjust the signal coupling from the central conductor 11 to the directional coupling conductor 21. The feature that the shielding cover 22 can be detachably attached to the shielding shutter 13 enables the direction in which the signal coupling occurs to be selected by selecting the orientation in which said shielding cover 22 is attached to said shielding shutter 13.

0021Fig. 5 is a perspective view showing a second embodiment of the invention and Fig. 6 is a sectional view illustrating a configuration of this second embodiment. The second embodiment of the inventive high frequency signal line is similar to the first embodiment in that the transmission line 10 comprises the central conductor 11 and the outer conductor 12 and that the transmission line 10 is covered with the shielding shutter 13 closely in contact with said transmission line 10.

0022An induction line 30, on the other hand, includes a shielding cover 32 which includes, in turn, a joint web 34 integrally provided on its inner side and having a width substantially corresponding to the width of the outer conductor 12. Within said shielding cover 32, there is provided a directional coupling conductor 31 extending in parallel to said central conductor 11 and to which the signal output from said central conductor 11 is coupled. Said directional coupling conductor 31 is connected to a branch circuit (not shown) by a connector 33 mounted on an end of said directional coupling conductor 31.

0023With such arrangement of the second embodiment, the signal output from the central conductor 11 can be coupled to the directional coupling conductor 31 without an apprehension that said directional coupling conductor 31 might come in physical contact with said outer conductor 12, because the shielding shutter 13 may be covered with the shielding cover 32 to prevent said outer conductor 12 as well as said shielding shutter 13 from being further rotated. Just as in the case of the previously mentioned first embodiment, the shielding cover 32 can be detachably attached to the shielding shutter 13 and therefore the direction in which the signal coupling occurs can be selected by selecting the orientation in which said shielding cover 32 is attached to said shielding shutter 13.

0024Typical computer LAN by coaxial cable practically adopts a connector pin extending through the outer conductor of the coaxial cable and directly inserted into the central conductor alone. The present invention also can be implemented by an arrangement such that the connector 23 or 33 is provided directly in contact with the central conductor 11.

0025In either embodiment, the induction line 20 or 30 is kept away from the transmission line 10 and thereby the longitudinal opening of said transmission line is released to enable the signal leakage. The shielding shutter 13 is rotated to adjust a width of said opening and thereby to adjust a leakage field strength. A plane of polarized wave generated thereby is a horizontal polarized wave of a wide frequency range.

0026Fig. 7 is a perspective view showing a third embodiment of the invention. The high frequency signal line according to the third embodiment comprises a transmission line 40 consisting of a central conductor 41 and a cylindrical outer conductor 42 provided with a longitudinal opening. The transmission line 40 is covered with a cylindrical shielding shutter 43 which is closely in contact with said transmission line 40. The shielding shutter 43 is partially formed with a spiral opening. A plurality of such shielding shutters 43, 43' are arranged adjacent one another.

0027The longitudinal opening of the outer conductor 42 and the spiral openings of the respective shielding shutters 43, 43' define together a plurality of leakage openings 45, 45' and signal leakage occurs between each pair of adjacent leakage openings 45, 45'. The shielding shutters 43 are individually rotatable and one of them may be rotated relatively to the adjacent shielding shutter to change a pitch between each pair of adjacent leakage openings 45, 45' and thereby to change a wave length of the leak signal. In this case, the polarized wave is vertical.

0028Fig. 8 is a perspective view showing a fourth embodiment of the invention. The fourth embodiment of the high frequency signal line comprises a transmission line 50 consisting of central conductor 51 and a cylindrical outer conductor 52 having a spiral opening. The transmission line 50 is covered with a cylindrical shielding shutter 53 adapted to be closely in contact with said transmission line 50. Said shielding shutter is partially formed with a longitudinal opening. A plurality of such shielding shutters 53, 53' are arranged adjacent one another.

0029The spiral opening of the outer conductor 52 and the longitudinal openings of the respective shielding shutters 53 define together a plurality of leakage openings 55, 55' and signal leakage occurs between each pair of adjacent leakage openings 55, 55'. The shielding shutters 53 are individually rotatable and one of them may be rotated relatively to the adjacent shielding shutter to change a pitch between each pair of adjacent leakage openings 55, 55' and thereby to change a wave length of the leak signal. In this case also, the polarized wave is vertical.

0030Fig. 9 is a perspective view showing a fifth embodiment of the invention and Fig. 10 is a sectional view showing this fifth embodiment. The fifth embodiment of the high frequency signal line comprises a transmission line 60 consisting of a central conductor 61 and a cylindrical outer conductor 62 having a longitudinal opening. The outer conductor 62 is integrally provided with a pair of plate-like rail supporting wings 65, 65 extending outward from both sides of said outer conductor 62 and rails 66, 66 are laid on the respective supporting wings 65, 65.

0031An induction line 70 comprises a plate-like shielding cover 72 provided with wheels 74, 74, 74, 74 so that said shielding cover 72 may be moved along said rails 66, 66. The shielding cover 72 is additionally provided with a directional coupling conductor 71 extending below said shielding cover 72 in parallel to the central conductor 61 so that the signal output from said central conductor 61 may be high frequency coupled to said directional coupling conductor 71. This directional coupling conductor 71 can be connected to a branch circuit (not shown) by a connector 73 mounted on an end of said directional coupling conductor 71.

0032With the arrangement as has been described just above, movement of the shielding cover 72 can be easily achieved by rolling the wheels 74, 74, 74, 74 of the shielding cover 72 on the rails 65, 65. Accordingly, a transmitter (not shown) may be connected to the connector 73 to achieve a continuous data transmission with said shielding cover 72 being adjustably moved.

0033The fifth embodiment is similar to the first embodiment in that the shielding cover 72 can be detachably attached to the outer conductor 62 and therefore the direction of signal coupling can be selected by selecting the orientation in which said shielding cover 72 is attached to said outer conductor 62.

0034While this embodiment has been described above as the rail supporting wings 65, 65 being provided integrally with the outer conductor 62, an alternative arrangement is also possible such that there is provided a cylindrical shielding shutter having a longitudinal opening and a pair of plate-like rail supporting wings 65, 65 are provided on opposite sides of said longitudinal opening, respectively, integrally with said shielding shutter. It is also possible to provide, separately of the outer conductor 62 as well as the shielding shutter, such pair of rail supporting wings 65, 65 along opposite sides defining the opening of the outer conductor 62.

0035While the fifth embodiment has been illustrated and described as the induction line 70 is moved along the upper side of the transmission line 60, it is also possible to provide the induction line 70 so as to be moved along the lower side of the transmission line 60.

0036While the invention has been described hereinabove as the outer conductor 12, 42 or 52 and the shielding shutter 13, 43 or 53 are provided in the form of cylindrical tubes, said outer conductor 12, 42 or 52 as well as said shielding shutter 13, 43 or 53 may be provided in the form of polygonal tubes so far as said shielding shutter 12, 42 or 52 is rotatable.

Effect of the Invention

0037As will be apparent from the foregoing description, the high frequency signal line according to the invention comprises the transmission line consisting of the central conductor and the cylindrical outer conductor formed with the longitudinal opening, said transmission line being covered with the cylindrical shielding shutter formed with the longitudinal opening, on one hand, and the induction line consisting of the trough-shaped shielding cover formed with the longitudinal opening and adapted to be detachably attached to said shielding shutter and the directional coupling conductor extending within said shielding cover in parallel to said central conductor for high frequency coupling, on the other hand. Such novel arrangement advantageously eliminates the apprehension that the outer conductor and the directional coupling conductor might come in contact with each other and cause any malfunction. Such arrangement allows also, depending on the requirement for operation, the opening of the outer conductor to be adjustably widened or restricted and thereby the branched output can be easily adjusted. In other words, adjustment of the branched output can be performed using the shielding cover of one and same length, i.e., independently of the induction line's length.

0038The unique arrangement such that the transmission line consists of the central conductor and the cylindrical outer conductor formed with the longitudinal opening, said transmission line being covered with the cylindrical shielding shutter formed with the longitudinal opening and the induction line consists of the shielding cover adapted to be detachably fastened under an interlocking effect to said outer conductor and the directional coupling conductor for high frequency coupling which extends within said shielding cover in parallel to said central conductor is particularly effective to eliminate the apprehension that the outer conductor and the directional coupling conductor might come in contact with each other and cause any malfunction.

0039Additionally, the arrangement as mentioned just above allows a strength of the leakage field to be easily adjusted by widening or restricting the opening of the transmission line.

0040According to the alternative arrangements, the transmission line consists of the central conductor and the cylindrical outer conductor formed with the longitudinal opening and said transmission line is covered with the cylindrical shielding shutter partially formed with the spiral opening, or said transmission line consists of the central conductor and the cylindrical outer conductor formed with the spiral opening and said transmission line is covered with the cylindrical shielding shutter partially formed with the longitudinal opening. These arrangements allow a frequency of the leak signal to be adjustably changed depending on the requirement of operation.

0041Alternatively, the transmission may consist of the central conductor and the cylindrical outer conductor formed with the longitudinal opening and said outer conductor is provided along opposite sides defining said opening with the pair of rail supporting wings, respectively, on which the rails are laid in parallel to said outer conductor, on one hand, and the induction line may consist of the plate-like shielding cover provided with the wheels by which said shielding cover can be moved along said rails and the directional coupling conductor extending within said shielding cover in parallel to said central conductor, on the other hand. Such arrangement facilitates the shielding cover to be moved without an apprehension that the outer and induction conductors might come in contact with each other. Accordingly, this arrangement is particularly effective to achieve continuous data transmission with the shielding cover being adjustably moved.