DE2334550A1 - COAXIAL RESONATOR - Google Patents

Description

Spinner GmbH Electrotechnical Factory, 8 Munich 2,

Erzgießereistr. J5j5.

Coaxial resonator

The invention relates to a high quality coaxial resonator.

In high-frequency technology, especially in the production of filters for picture-tone switches for television transmitters, one needs Particularly high quality resonators that have to be operated with very high reactive powers.

Another requirement that must be made of such resonators is consists of a very large tunability that is up to one Octave can be, whereby the quality and the coupling ratios should change little. On the other hand, it should be possible to set these values with simple means.

In order to meet these requirements, cavity resonators have hitherto been used in the form of rectangular and circular spaces, because it was not yet possible to create such resonance circles in a coaxial Construction method, since the size of a coaxial circuit is determined by the cut-off frequency at which other oscillation modes occur. In order to achieve the required quality, however, dimensions would have been required that do not allow the unambiguousness of the oscillation modes would have guaranteed more.

Even with the known cavity resonators, however, the tuning prepares in a wide frequency range, as well as the coupling,

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considerable difficulties. Another disadvantage of known resonators is that it is very difficult to get good temperature compensation.

The invention is based on the object of providing a resonator in To create coaxial construction that meets all of the aforementioned requirements and the disadvantages of known cavity resonators avoids.

According to the invention, this object is achieved in that an X, / 2 long inner conductor is arranged in an outer conductor tube.

The invention is based on the knowledge that a coaxial resonator can be created which, contrary to the previously known shape, neither a / 4 circle nor an Xfc short-circuited at both ends. A circle is when a / t / 2 resonator is designed as a coaxial line piece that is freely accommodated in an outer conductor, the length of which can be of any length. The waveform is to be determined in such a way that the two ends vibrate with a 180 ° phase shift in the tension belly, while the tension between the outer conductor and inner conductor is zero in the middle of the coaxial line piece.

The invention is also based on the knowledge that the quality of a> * · / 4 resonance circuit is due to the ohmic losses of the Short circuit plate is essential and that the invention No such currents occurred in the resonator.

The coordination of the inner conductor can be done by a shaft made of insulating material and by one on a stress-free one Central point arranged insulating washer is performed. The coupling can take place as a current coupling through a transverse slot, a coaxial line being routed axially parallel to the resonator line and partial currents of this outside the resonator

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Line to flow through the slot into the resonator.

In the case of larger frequency ranges, the mechanical stroke, which is inevitably limited by the absolute length of the inner conductor, can occur Attachment of screw-on extension pieces can be expanded, so that a gradual range adjustment is made possible.

The coupling of the resonance circuit to a coaxial line can according to According to a further embodiment of the invention, a dummy line is also provided at the coupling point of the coaxial line is coupled via a capacitance, the length of the dummy line (vote) is set so that at the Instead of the coupling of the resonator to the coaxial line, the reactance caused by this coupling is compensated will. The capacity can be designed to be variable.

It has been shown that the diameter of the conductors can be larger than the coherence range.

An exemplary embodiment of the invention is described below with reference to the drawing. The single figure of the drawing shows an axial section of a coaxial resonator according to the invention. The inner conductor section 1 with a length of approximately 1/2 (0.35 ... 0.45 Ti) is arranged concentrically in an outer conductor tube 3 and is held in this position by a metallic, electrically conductive support J. Two tuning slides 41, 42 can be extended and retracted symmetrically or asymmetrically to the support J. At the point 91 or 92, an electrically conductive connection from the inner conductor tube 1 to the movable piston 41 or 42 is established via spring contacts. A screw spindle 10 is mounted concentrically within the inner conductor section 1 and has a left-hand thread L in the left-hand part and a right-hand thread R in the right-hand part. This spindle is in the middle of a double row ball bearing 60

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worn free of play. The outer race of the ball bearings is carried by inserts 63, 64, which are fixed in the inner conductor tube 10 are.

The spindle 10 carries a bevel gear 71 which meshes with a bevel gear 72 which sits on a shaft 80 which passes through the hollow Metal support J5 is guided and stored in this. On both of them Threaded sections L and R of the screw spindle 10 run spindle nuts 51 and 52, respectively, which are used to achieve a backlash-free thread are slotted and rest on the spindle with their own spring force. At the point 45 there is an internal thread in both pistons, that allows the attachment of additional extensions to change the tuning range. The pistons 41,42 are axially guided by pins 6l and 62, which prevent rotation of the pistons during actuation.

The spindle 10 and the two spindle nuts 5I and 52 are made of a material that has a very low coefficient of thermal expansion.

Instead of the metal support J5, an insulating support can also be used the voltage-free center point. The connection between the piston 41 and a flange of the spindle nut 5I or 52 is done by screws 46.

The drive shaft 80 or the bevel gear 72 is via a ball bearing 8l is supported on the insert 63.

As a result of the opposing thread arrangement, turning the Shaft 80 via the bevel gears 72, 71 and the spindle 10 is in the same direction Displacement of the pistons 41 and 42 causes outward and inward, respectively.

Claims;

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Claims (1)

Patent claims: ; ΐ \ coaxial resonator, * _Λ , 4 u *. changed characterized, that an inner conductor section (10) of a length of approximately A / 2 is arranged in an outer conductor tube (2). 2. Resonator according to claim 1, characterized in that the inner conductor (1) at its stress-free center point is supported by an insulating support in the outer conductor tube (2). 5. Resonator according to claim 1, characterized there that the inner conductor section (1) at its stress-free Central point is suspended on a radial metallic support (3) on the outer conductor tube (2). 4. resonator according to claim j5, characterized in that the metallic support by a T-shaped change of the outer conductor is about 1/4 of the mean wavelength. 5. Resonator according to claims 1 to 4, characterized in that the inner conductor is made of a material of low thermal expansion consists. 6. resonator according to claim 1, characterized in that the length of the inner conductor section (l) corresponds to Frequency is adjustable. 409885/0576 7. resonator according to claim 6, characterized in that the hollow inner conductor (1) has two pistons (41, 42) leads that are symmetrically adjustable outwards or inwards, 8. resonator according to claims 6 and 7, characterized thereby marked, that the piston by a movement spindle (10) with opposite Threaded sections (L, R) are adjustable via spindle nuts, with the spindle made of one material less There is thermal expansion. 9. resonator according to claims 2 and 6, characterized thereby marked, that the Cänge / des ^ inner conductor (10) by one made of insulating material existing shaft (80) takes place, which is guided radially through the insulating washer. 10. Resonator according to Claims 3 and 6, characterized in that it is marked, that the drive shaft (80) is guided through the metallic support (3). 11. Resonator according to claim 1, characterized in that the coupling is designed as a current coupling and through a transverse slot takes place and that outside of the resonator a coaxial line is axially parallel to the resonator line and partial currents of this line flow through the slot into the resonator. A09885 / 0576 12. Resonator according to claim 11, characterized in that that an axially parallel slot is provided through which a coupling loop dips into the resonator. 15. Resonator according to claim 6, characterized in that for larger frequency ranges the absolute length of the inner conductor section necessarily limited mechanical The stroke can be extended by attaching screw-on extension pieces, creating a gradual division of the area he follows. 14. Resonator according to claim 1J>, characterized in that the extension pieces in internal threads (45) of the spindle nuts (51) can be screwed in. 15. Resonator according to claim 12, characterized in that the Koppfeischleife is displaceable in length to the To vary the phase position, i.e. the location of the coupling on the line. 16. Resonator according to one of claims 1 to 15, characterized in that that the outer conductor (2) is seamless in the center of symmetry. 17. Resonator according to claim 5, characterized in that several metallic support supports, e.g. in triplicate or fourfold execution have been carried out. 409885/0576 18. Resonator according to claim 6, characterized in that the inner conductor is externally driven by a push rod drive is adjustable. 19. Resonator according to claim 6, characterized in that the vote on a gaseous or liquid Medium is transferred to the inner conductor. 20. Resonator according to claim 19, characterized in that the liquid or gaseous used for adjustment Medium serves to cool the inner conductor at the same time. 21. Resonator according to one of claims 1 to 20, characterized in that that the outer conductor tube (2) is placed vertically and designed to be open, so that cooling by its own convection of the room and the inner conductor takes place. 22. Resonator according to one of claims 1 to 21, characterized in that that for the purpose of coupling the resonator to a coaxial line at the coupling point of the coaxial line, a dummy line is coupled via capacitance, the length of the stub line (Vote) is set so that at the point of coupling of the resonator to the coaxial line through this coupling-related reactance is compensated. 409885/0576 23. Resonator according to claim 22, characterized in that the capacitance effecting the coupling can be changed. 24. Resonator according to claim 1 and 11,
characterized in that the two ends of the inner conductor of the resonator can be adjusted asymmetrically so that the position of the coupling gap is shifted to the axis of symmetry when the frequency changes, whereby the necessary change in the coupling is effected depending on the frequency. 25. Resonator according to claim 6 to 9 or 24, characterized in that the spindle thread (L, R) has different pitches. 409885/0576 Blank page