DE20016787U1 - Circuit for splitting or merging high-frequency power - Google Patents

Description

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345 G258

Circuit for splitting or combining high frequency power

The invention relates to a circuit for splitting or combining high-frequency power according to the preamble of claim 1.

Circuits for splitting or combining high-frequency power are known as bridge circuits or Wilkinson couplers. They are used in high-frequency technology primarily for connecting high-frequency transmitters or antennas in parallel.

0 A generic circuit for splitting and combining high frequency power is known, for example, from the Kathrein-Werke KG brochure "Base Station Antennas for Mobile Communication, Catalogue 03.99".

The circuit is arranged in an elongated housing, for example, on one end of which the so-called summing

mentor (entrance) and at the opposite end, for example, a first single gate and a second single gate on a transverse side adjacent at right angles to it.
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Power distribution is achieved by using different resistors on the individual gate (parallel connection of different individual gate resistors). The first individual gate remains unchanged. The second individual gate is subjected to a λ/4 transformation, for example. In other words, power distribution is achieved according to the state of the art using a different impedance Z ("λ/4 transformation"). However, power distribution has a retroactive effect on the input. Above all, in the case of different division ratios, these cannot be set variably, so that different types and devices must be made available for the different power division ratios.

The object of the present invention is therefore to provide, on the basis of the last-mentioned generic prior art, an improved circuit for power distribution, in particular an improved variable circuit for dividing or combining high-frequency powers.

The object is achieved according to the features specified in claim 1. Advantageous embodiments of the invention are specified in the subclaims.

The circuit arrangement according to the invention is not only new, but is also highly surprising in its overall structure and in view of the advantages that can be achieved as a result. In a preferred embodiment, the circuit arrangement according to the invention makes it possible to implement a variable power distribution without changing the input impedance. This is achieved according to the invention by a combination of variable coupling capacitances and a variable stub line, whereby both elements can preferably be varied with a common control element.

The power distribution is preferably carried out in such a way that a further line branches off from a continuous RF line at a defined point, which is capacitively coupled. In this case, a transformation for the resistance adjustment is implemented at the input or sum gate, without this - as mentioned - having an effect on or changing the input impedance. Frequency compensation or frequency predistortion is effected on the coupled-out branch. According to the invention, the power distribution can now be changed by easily adjusting a provided setting or adjustment element, and without any reaction to the input impedance. According to the invention, for different power division ratios, not only different types of devices are now necessary, but only one type that can be adjusted differently.

0 The circuit arrangement according to the invention is therefore suitable for

to install a wide variety of power branches in an HF broadband network, for example in signal transmission in a building for the various power branches on the individual floors, building complexes, etc. Simply by turning an adjusting element, the desired power distribution can be easily set according to the power branching to be carried out. If one also considers that a large number of distributors are usually required when wiring a house in order to divide the fed-in signals (for example in the basement) between a large number of lines and, for example, to divide the power again on the individual floors of a house between different branch lines with possibly always different power components, the advantages of the invention become all the more clear. This is because according to the invention only a single switching device is required for, in particular, continuous power distribution, which can be easily set to the current requirements, whereby compensation for the different cable lengths, cable attenuations, etc. can now be easily carried out.

The power distribution according to the invention is preferably implemented using a balancing element which is arranged in a positionally variable manner. The change in position changes the coupling of the power into the branching line and, according to the invention, simultaneously compensates for the change in resistance caused by the changed coupling. The mechanically positionally variable

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The adjustable adjustment element can be electrically conductive, but it does not have to be. A dielectric adjustment element can also be used.

In a particularly preferred embodiment of the invention, the adjusting element can be arranged in axial extension to the branching line, wherein the main line running between the input and the further output gate (i.e. between the sum gate and the further individual gate) is arranged transversely thereto.

The desired modified decoupling can preferably be carried out by means of a mechanically adjustable probe, which can be changed in its axial position, for example, by radial rotation.

The adjustment element can also be adjusted differently, for example, by a different type of adjustment mechanism. For this purpose, in a further preferred embodiment, it is provided that the actuator on the circuit housing can be adjusted linearly. The adjustment movement preferably takes place in the axial longitudinal direction of the circuit housing. The adjustment movement, i.e. preferably the linear adjustment movement of the adjustment element, can be realized and implemented via this adjustment movement, preferably inside the adjustment element, with the adjustment movement of the adjustment element taking place perpendicular to the adjustment movement of the actuator. The entire arrangement has the further advantage that, for example, a clearly visible scale can be attached.

Depending on the adjustment position of the adjustment element, it is possible to read exactly which power distribution is currently set.

Finally, the transmission between the actuator and the adjustment element can also be non-linear if desired. Otherwise, a linear transmission can be implemented at any time.

The bandwidth of the decoupling unit can be very large, for example 45%.

The circuit arrangement according to the invention can be constructed coaxially. However, it can also be implemented using discrete components or circuit board technology.

For the sake of completeness, it is noted that the circuit according to the invention can also comprise several variable coupling elements for constructing an n-fold distributor 0.

The invention is explained in more detail below with reference to drawings.

Figure 1 : an equivalent circuit according to the invention with

discrete elements for explaining the functionalities of the structure of a circuit according to the invention for dividing or combining high-frequency power;

Figure 2: an embodiment which essentially corresponds to Figure 1, which is suitable for a variable, broadband power distribution, in which a common actuator for effecting the

different distribution of services is provided;

Figure 3 : a schematic representation to explain a concrete embodiment

concerning a coaxial circuit design;

Figure 4: a schematic sectional view through an embodiment according to the invention

with corresponding basic representation according to Figure 3;

Figure 5: a partial cross-sectional view through the thickened inner conductor section

section in Figure 4 with the cross hole made there;

Figure 6: a schematic side view of the device according to the invention for power distribution

in a first setting position of the actuator;

Figure 7: a side view corresponding to Figure 6, in which the actuator for

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To achieve a different power distribution, the position is different from that in Figure 6;

Figure 8: a side view of the device according to the invention corresponding to Figure 6, partly in longitudinal section;

Figure 9: a side view corresponding to Figure 7 of the device according to the invention for

Power distribution according to the second switching position according to Figure 7, but shown partly in longitudinal section; and

Figure 10 : a horizontal cross-sectional view

perpendicular to the sectional views shown in Figures 8 and 9, in the switching position shown in Figures 6 and 8.

Figure 1 shows an equivalent circuit diagram of a variable, broadband power distribution circuit, which is used to explain the basic principle.

The circuit comprises a first input or sum gate 1 as well as a first output or single gate 3 and a second output or single gate 5.

Between the entrance and the first exit gate 3 is usually the so-called main line 7 (main line)

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from which a branch line 11 branches off at a branching point 9. Usually, a power that is less than 50% of the total power fed into the input 1 is branched off at the second output port 5.

Between the input gate 1 and the branching point 9, a system impedance of 50 Ω is realized in the main line 7.

The main line 7 basically consists of one or more RF lines 13 connected in series, i.e. RF line sections 13.1, 13.2, ... to 13.5 in the embodiment shown. The branch line 11 also consists of a coaxial line with a first RF line section 15.1, a capacitor 18 also marked with the designation C ₃ , a further downstream RF line section 15.2, a further capacitor 22 also marked as capacitor C ₂ and further downstream RF line sections 15.3, 15.4 etc.

A first coupling point 27 is provided between the first RF line section 15.1 and the first capacitor 18, and a second coupling point 29 is provided between the further capacitor 22 and the subsequent RF line section 15.3, between which a capacitor 33, also partially identified below as capacitor C ₁ , is connected in a parallel branch 31.

Between the capacitor 18 and the RF line section

15.2, an open spur line 37 is provided at the branch 35 provided there.

The capacitors 18, 22 mentioned and the electrically effective length of the stub line 37 are each designed as adjustable, variable components. The capacitor connected in the parallel branch 31 can also be designed as a variable capacitor, but this does not have to be the case.

A common setting logic or mechanism can be used to ensure that the RF power branching off at the second output 5 can be variably and continuously adjusted by jointly adjusting the variable capacitors and changing the length of the stub line 37, whereby the power available at the first output 3 is reduced accordingly according to the power portion branched off. The setting is made without affecting or changing the input impedance at input 1. In addition, a corresponding resistance pre-distortion is carried out in order to achieve the desired resistance compensation overall.

Figure 2 shows a further equivalent circuit diagram for the embodiment according to Figure 1 for a variable, broadband power distribution. The unit 41 is shown in dashed lines, which can be adjusted by a common actuator (symbolized by the common arrow crossing the unit 41) to effect a different power distribution.

Figure 2 also shows a dotted line at the branching point 9 that an additional stub line 42 may be provided here for resistance adjustment.
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Figure 3 shows the schematic structure of an embodiment of a circuit according to the invention using a coaxial structure, which is discussed in greater detail below with reference to Figures 4 and 5.

The housing 43 of the circuit arrangement consists, for example, of a square tube with a hollow cylindrical interior as an outer conductor 13", through which a rod-shaped inner conductor 13' is guided. A corresponding coaxial socket can therefore be arranged on the opposite end faces at the input or at the first output port 1, 3, the inner conductor of which is connected to the inner conductor 13' and the outer conductor of which is connected to the outer conductor 13" of the circuit arrangement.

On the side 44 adjacent to the opposite end face, in the vicinity of the first output port 3, the second output port 5 is provided, which can also be designed as an RF connection with a corresponding RF socket, as can be seen in greater detail in the schematic cross-sectional representation according to Figure 4.

0 From the schematic cross-sectional view according to Figure

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4 it can be seen that the main line 7 consists of the aforementioned coaxial tube 43, wherein the outer conductor 13" forms the housing 43 of the circuit arrangement, and the inner conductor 13' is guided through the interior as a metallically conductive rod, galvanically separated from it. For this purpose, the electrically conductive metallic rod serving as the inner conductor 13' is mounted and held in corresponding insulator supports 46, which are preferably made of plastic, at least in the area of the input port 1 and the first output port 3 at the end of the main line 7, and is thereby galvanically separated from the housing.

At the level of the second output gate 5, the electrically continuous inner conductor or rod 13' of the main line 7 has a thickened section 45 with a transverse bore 47, within which, in the embodiment shown, a sleeve-shaped insulator 49, preferably made of plastic, is incorporated. As can be seen from the partial cross-sectional view (rotated by 90') in Figure 5, this does not cause a conductive interruption of the inner conductor 13'.

The rod-shaped inner conductor 15' of the coaxial connecting line or of the coaxial connection for the second output port 5 is provided axially aligned with the transverse bore 47, which comprises a sleeve- or pot-shaped end section 51 adjacent to the transverse bore 47 in the inner conductor 13' of the main line 7, which in the embodiment shown is also provided on the inside with a hollow cylindrical insulator 53, preferably made of plastic.

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Axially opposite on the other side of the outer conductor or housing 43 is an actuator 55, shown in the embodiment shown with a spindle 57, in order to push an adjustment element 61 further in or back in the axial direction by turning it in accordance with the arrow 59. The actuator 55 with the spindle 57 are not electrically conductive, at least not coupled to the outer conductor 13". The spindle 57 is used to adjust the adjustment element 61, which is metallic in the embodiment shown, axially in different ways, with the adjustment element 61 passing through the hollow cylindrical thickened section 45 of the inner conductor 13' of the main line 7 and engaging to different extents in the hollow cylindrical inner conductor 15', which is galvanically isolated from the inner conductor 13' of the main line.

The capacitor C ₃ (18) mentioned is formed by the hollow cylinder or sleeve-shaped body 45 belonging to the inner conductor 13■ of the main line 7 and the cylindrical adjustment element 61 passing through this sleeve-shaped body 45. Since the adjustment element also engages to varying degrees in the further sleeve-shaped or bush-shaped body 51 aligned with the sleeve-shaped body 45, the further capacitor C ₂ (22) is formed between the adjustment element 61 and this sleeve-shaped body 51.

Finally, the two galvanically separated sleeve-shaped bodies 45 (which are electrically connected to the inner conductor 13' of the main line,7

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is) and the sleeve-shaped body 51 axially spaced therefrom (which is electrically connected to the inner conductor 15' of the branch line 11) forms the capacitor C ₁ (33) also already mentioned.
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As mentioned, by turning the adjusting element, the adjustment element is adjusted axially, thereby changing the capacitor C ₃ and especially C _2. Since the axial distance between the two sleeve-shaped bodies 45, 51 does not change, the capacitor C ₁ formed between these components is unchangeable in this embodiment. By turning the adjustment element in and out accordingly, the electrically effective length of the open stub line 37 is also changed accordingly, with the electrical length of the stub line 37 becoming shorter the further the adjustment element 61 engages in the corresponding sleeve-shaped body 51 of the stub line.

Instead of the electrically conductive adjustment element 61, a non-conductive adjustment element 61 can also be used, which also offers the advantage that the mentioned insulators inside the sleeve- or pot-shaped adjustment elements 45, 51 can then be dispensed with in any case.

A broadband power splitter with variable adjustment can be used without any problems in a broadband RF range of, for example, 800 MHz to 2200 MHz.

The difference in power distribution Δ�R between output ports 3 and 5 can be between 5 dB and 2 0 dB.

The embodiment has been explained using an open stub line 37. However, at least in certain applications, a closed stub line 37 is also possible.

With reference to Figures 6 to 10, a more concrete embodiment will now be described, which differs from the preceding embodiments primarily in that the actuator 55 is not designed as a rotatable actuator 55'.

Figure 6 shows a corresponding device according to the invention for power distribution in side view with the housing 43 with a square cross section extending in the axial longitudinal direction between the input port 1 and the input and output ports 3.

At the level of the second exit gate 5, which is aligned transversely thereto, the linearly adjustable actuator 55 is shown, which is cuboid-shaped and encompasses the axially extending housing 43. This cuboid-shaped actuator 55" is adjustable along the arrow representation 71 in the longitudinal direction of the housing 43 and is shown in Figure 6 in one of its end positions and in Figure 7 in its other extreme or end position opposite thereto.

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The cuboid-shaped actuator housing 55" has, on one of its actuator sides 73, a recess, for example a rectangular recess or a corresponding field of view, with this recess or field of view 75 being assigned an adjustment or reading device 77, in the embodiment shown in the form of a protruding nose 77'. Below the field of view 75, i.e. the recess 75, a scale 79 is attached to the outside of the housing wall 43' of the housing 43 located underneath. According to the axial adjustment movement of the actuator 55', it can now be read exactly on the scale 79 how the power distribution is carried out in accordance with the setting of the actuator 75' at the two recesses 3 and 5.

How the adjustment mechanism works can be seen from Figures 8 to 10, which show the corresponding device partly in cross-section.

0 From the sectional view according to Figures 8 and 9 it is evident that a sleeve-shaped insulator 53 is accommodated in the sleeve or in the pot-shaped end section 51, along which the adjustment element 61 can be axially adjusted transversely to the axial direction of the housing 53 - as discussed in the previous embodiments. The axial adjustment movement of the adjustment element 61 is accomplished via a nozzle-shaped transmission element 81 in the embodiment shown, which is axially fixedly connected to the adjustment element 61 and together with it relative to the

sleeve- or cup-shaped end section 51 is adjustable.

As can be seen from the illustration according to Figures 8 and 9, in the actuator 55" adjustable in the direction of arrow 71, a link guide 83 in the form of a guide groove 83' is introduced on the inside of a front and rear side wall section 56, in which a guide pin 85 protruding perpendicular thereto engages, which is formed on the transmission member 81 or fastened thereto.

An adjustment movement of the cuboid actuator 55' in the axial direction 71, i.e. in the axial longitudinal direction of the housing 43, necessarily causes an adjustment movement perpendicular to it, namely in the adjustment direction 87. This is because the guide pin 85 held by the transmission member 81 cannot follow an axial longitudinal adjustment direction according to the arrow representation 71 and is held by the corresponding adjustment movement of the actuator 55 following the respective position of the guide groove 83', whereby the transmission member 81 and thus also the adjustment element 61 necessarily carry out the desired adjustment movement in the direction of the arrow representation 87. The transmission member 81 is therefore guided in a sleeve 89.

5 Deviating from the embodiment shown, the slotted guide 83 or the guide groove 83' can be designed linearly. This results in a linear transmission. The degree of transmission depends on the groove pitch and can, for example, be in the order of magnitude of approximately 1:2. The slotted guide or the guide groove can

but also be curved, as shown in the embodiment according to Figures 8 and 9, whereby a corresponding axial adjustment movement in the direction of arrow 71 is translated into a different intensity of immersion movement or return movement of the adjustment element 61 in the cavity or in the cup-shaped end section 51.

The scale 79 mentioned above must then be designed according to the transmission ratio and the capacitor effect in order to clearly read which power distribution is set.

Claims (23)

1. Circuit for splitting or combining high frequency power, with a main line or main section ( 7 ) connected between an input and a first output port ( 1 , 3 ), and a branch line (11) branching off from the main line at a branching point ( 9 ) and leading to a second output port ( 5 ), characterized in that a stub line ( 37) coupled to the branch line (11 ) is provided, the electrical length of which can be changed such that the change in resistance caused by the changed power distribution can also be compensated for with the changed size of the branched power. 2. Circuit according to claim 1, characterized in that to compensate for the change in resistance depending on the branched power, a particularly adjustable or differently preselectable and/or installable or removable balancing element ( 61 ) is provided, which is preferably a part of at least one capacitor (C ₂ , C ₃ ) connected to a branch line ( 11 ) or is coupled to such a part. 3. Circuit according to claim 2, characterized in that the balancing element ( 61 ) is constructed in such a way that when the branched power component changes, the electrical length of the stub line ( 37 ) coupled to the branch line ( 11 ) changes simultaneously for the purpose of compensating the associated change in resistance. 4. Circuit according to claims 1 to 3, characterized in that at least two variable capacitors (C ₁ , C ₂ , C ₃ ) are provided in the branch line ( 11 ), and that the capacitances can be changed by changing a common actuator or adjustment element ( 61 ). 5. Circuit according to one of claims 1 to 4, characterized in that at least two series-connected capacitors (C ₃ , C ₂ ) are provided in the branch line ( 11 ), the capacitance of which can be changed by axial position change of the balancing element ( 61 ). 6. Circuit according to one of claims 1 to 5, characterized in that the inner conductor ( 13 ') of the main line ( 7 ) has a section ( 45 ) provided with a transverse bore ( 47 ), to which a further sleeve-shaped body belonging to the inner conductor ( 15 ') of the branch line ( 7 ) is provided, axially offset and galvanically separated, wherein the balancing element ( 61 ) passing through the two sleeve-shaped bodies ( 45 , 51 ) can be changed by changing the capacitance of the capacitors (C ₂ , C ₃ , C ₁ ). 7. Circuit according to one of claims 1 to 6, characterized in that the adjustment element ( 61 ) is electrically conductive. 8. Circuit according to one of claims 1 to 7, characterized in that the adjustment element ( 61 ) is electrically non-conductive. 9. Circuit according to claim 7 or 8, characterized in that the adjustment element ( 61 ) is separated from the sleeve-shaped bodies ( 45 , 51 ) by creating a spacing gap and/or is galvanically separated by using an insulator, preferably made of plastic, provided on the adjustment element ( 61 ) and/or on the inside of the sleeve-shaped bodies ( 45 , 51 ). 10. Circuit according to one of claims 1 to 9, characterized in that the frontal axial distance between the two sleeve-shaped bodies ( 45 , 51 ) is constant, preselectable or variable. 11. Circuit according to one of claims 1 to 10, characterized in that the adjustment element ( 61 ) is connected to an adjusting body which is provided in axial extension of the branch line ( 11 ) on the opposite side to the main line ( 7 ). 12. Circuit according to one of claims 1 to 11, characterized in that the adjustment element ( 61 ) is connected to a spindle drive, via which it is axially adjustable. 13. Circuit according to one of claims 1 to 12, characterized in that the spindle drive is arranged on the opposite side to the branch line ( 15 ) on the housing ( 43 ) of the coaxial main line ( 7 ). 14. Circuit according to one of claims 1 to 11, characterized in that the adjustment element ( 61 ) is adjustable with a linearly adjustable actuator ( 55 , 55 "). 15. Circuit according to claim 14, characterized in that the adjustment element ( 61 ) is adjustable transversely, ie in particular with an adjustment direction ( 87 ) running perpendicular to the adjustment direction ( 71 ) of the actuator ( 55 , 55 "). 16. Circuit according to claim 14 or 15, characterized in that the actuator ( 55 ') has a link and/or guide groove ( 83 , 83 ') which interacts with a guide device or a guide pin ( 85 ) interacting therewith in such a way that a linear adjustment movement of the actuator ( 55 ') is translated into a linear adjustment movement of the adjustment element ( 61 ). 17. Circuit according to claim 16, characterized in that the guide device is designed in particular in the form of a guide pin ( 85 ) on a transmission member ( 81 ) which is connected to the adjustment element ( 61 ) and is adjustable together with the latter. 18. Circuit according to claim 16 or 17, characterized in that the transmission element ( 81 ) is designed in the shape of a nozzle and is preferably guided in a sleeve-shaped guide device ( 89 ) and is axially adjustable therefor. 19. Circuit according to one of claims 1 to 18, characterized in that the transmission ratio between the actuator ( 55 , 55 ") and the adjustment movement of the adjustment element ( 61 ) is proportional to one another. 20. Circuit according to one of claims 1 to 19, characterized in that the adjusting movement of the actuator ( 55 , 55 ") is non-proportional to the axial adjusting movement of the adjusting element ( 61 ). 21. Circuit according to claim 20, characterized in that the slotted guide ( 83 ) or the guide groove ( 83 ') is linear. 22. Circuit according to claim 21, characterized in that the slotted guide ( 83 ) or the guide groove ( 83 ') is curved. 23. Circuit according to one of claims 1 to 22, characterized in that the actuator ( 55 ) is designed with a scale ( 79 ) or a setting and reading device ( 77 ) which is provided with a setting or reading device ( 77 ) formed directly or indirectly on the housing ( 43 ) or a scale ( 79 ) formed there for reading the power distribution at the two output ports ( 3 , 5 ).