RU216628U1 - Power divider with phase shifter for base station antenna - Google Patents

Abstract

The utility model relates to cellular communication technology and is intended for dividing/summing microwave signals inside a base station antenna. The implementation of four conductive tracks as two-wire, ensuring the operation of an eight-element antenna array and an optimized structure of the tap-off element, the position of which determines the beam orientation, as well as the manufacturability of the contact of the device elements, makes it possible to achieve the reliability of a broadband transition in an extended operating frequency band of 617 ... 960 MHz. 2 w.p. f-ly, 5 ill.

Description

The utility model relates to cellular communication technology and is intended for dividing/summing microwave signals inside a base station antenna.

When installing and operating base station antennas, it is often necessary to change the position of the antenna beam in the vertical plane. This can be done by mechanically tilting the base station antenna housing, however, it is more convenient and technologically advanced to change the beam position electronically without resorting to rotating the antenna housing. Electronic-mechanical restructuring of the beam position is carried out by introducing certain phase shifts into the signals arriving at the corresponding elements of the phased antenna array, on the basis of which the base station antennas are built. These phase shifts can be introduced using phase shifters, however, in practice, a power divider is often used, combined with a phase shifter, which simultaneously has the ability to introduce the necessary phase shifts.

A known power divider with a phase shifter [Multi-line phase shifter for vertical beam tilt-controlled antenna, EP2430700, publ. November 13, 2013], in which phase shifts are controlled by moving the bends of microstrip lines. The divider includes a fixed plate, on which the transmission lines are located, and also includes a movable plate, which is installed with the possibility of longitudinal sliding in a position where it contacts the surface of the fixed plate. The disadvantage of this technical solution is the lack of structural reliability, since some moving metal parts rub against others.

A power divider is also known [Method for operating a phase-controlled group antenna and a phase shifter assembly and an associated phase-controlled group antenna, EP2406851, publ. 07/03/2013], containing concentric relative to the central point, located in a semicircle, conductive tracks in the form of strip sections, as well as a tap-off element with non-contact transitions to conductive tracks and with the possibility of rotation around the center. The disadvantage of this solution is the narrow band of operating frequencies. This device is selected as a prototype.

The task to be solved by the proposed utility model is to expand the operating frequency band in accordance with the requirements of the 5G standard.

This problem is solved by achieving a technical result, which consists in expanding the matching bandwidth of the implemented microwave transitions.

The specified technical result is achieved by the fact that the power divider with a phase shifter for the base station antenna, containing concentric relative to the central point, arcuate conductive tracks in the form of strip sections with an even number of emitters, as well as a tap-off element with non-contact transitions to conductive tracks and with the possibility of rotation around center, differs in that the number of conductive tracks in the form of strip sections is four and they are made two-wire on the inside of the printed circuit board, and the outlet element is made on the outside of the second printed circuit board adjacent close to the inside of the first, and the thickness of the second printed circuit board is three times less than the thickness of the first, and is equipped with four branches parallel to the arcuate conductive paths with a width of approximately 1/10 of the width of the two-wire conductive paths remote from the center of the conductors and with the possibility of movement along them, for which purpose a a rotating contact is made, the ends of the branches are equipped with rectangular bends, at the ends of which metal plates are fixed, located above the conductors of the two-wire conductive tracks closest to the center.

The rotating contact is made in the form of two contacting concentric metal rings located on the internal contacting sides of the printed circuit boards, and contains coaxial metallized holes with fastening for pressing the printed circuit boards to each other and reliability of the contact of the contacting concentric metal rings.

The essence of the utility model is illustrated by figures.

Figure 1 shows the main elements of the device.

Figure 2 shows the outer side of the printed circuit board with the input and outputs of the device.

Figure 3 shows part of the main element of changing the phases of the output signals.

Figure 4 shows the dependence of the width of the other part of the main element of the phase change of the output signals from the longitudinal coordinate.

5 illustrates the dependence of the voltage standing wave ratio (VSWR) at the device input on frequency.

The device consists of four arcuate conductive tracks 1, made in the form of two-wire lines on a printed circuit board (see Fig.1) with the formation of a gap between the conductors with a width of 2 mm. The outlet element 2, containing four branches 3, with sections parallel to the arcuate conductive paths, is made on the outer side of the second printed circuit board adjacent closely to the first inner side. The width of the branches 3 is approximately 1/10 of the width of the two-wire conductive tracks remote from the center of the conductors. The thickness of the second printed circuit board is three times less than the thickness of the first printed circuit board. The ends of each of the branches 3 are equipped with rectangular bends, at the ends of which metal plates 4 are fixed. At the ends of the slotted gaps between the lines of the conductive tracks, there are broadband microwave transitions 5, which are holes with metal plates adjacent to them on the outer side of the first printed circuit board (Fig. 2). Microwave connectors 6 are installed at the ends of the broadband microwave transitions 5. The arcuate conductive tracks 1 have a common center in which a rotating contact 7 is installed, which is the center of rotation of the tap-off element 2. The rotating contact 7 is connected to the input microwave connector 8 by a microstrip line 9.

Rotating contact 7 is made in the form of two contacting concentric metal rings 10 and 11. Ring 10 is located on the inside of the first printed circuit board, and ring 11 is on the inside of the second printed circuit board. The central regions of the rings 10 and 11 contain coaxial metallized holes with an inserted fastener, such as a screw and a nut, to press the printed circuit boards against each other and ensure the contact of the contacting rings 10 and 11.

The device works as follows. Through the input microwave connector 8 through the microstrip line 9, the signal enters the rotating contact 7. Due to the tight contact of the rings 10 and 11, the signal passes from the first printed circuit board to the outlet element 2, is divided into its branches 3 and enters the metal plates 4 on the second printed circuit board . The location of the plates 4 above the conductors of the two-wire conductive tracks 1 closest to the center provides broadband transitions to the slot gaps between the lines of the conductive tracks and the microwave transitions 5 and, thereby, to the microwave output connectors 6. The operation of the device imposes requirements on the length of the microwave cables connecting the device with an antenna array (not included in the device), namely, the electrical lengths of the microwave cables must ensure that the output signals are in phase when the metal plates 4 are in the central regions of the conductive tracks 1. The antenna beam is tilted by rotating the tap-off element 2, but the limits of its rotation should be limited except for the alignment of plates 4 with microwave transitions 5.

The outlet element 2 with its branches 3 consists of several microstrip lines with different wave impedance. The strip connected to the rotating contact 7, up to the branch point, is an optimized impedance transformer. At the point of connection to the rotating contact 7, the transformer has a characteristic impedance of 50 ohms (corresponding to that used in microwave technology). Due to the fact that the tap-off element is divided into four branches and the need to maintain the value of the wave resistance of 50 ohms on the plates 4, the wave resistance of the transformer at the branching point should be 12.5 ohms. From this condition, as a result of computer simulation, the dependence of the width of the transformer W on the longitudinal coordinate L, shown in Fig.4, is obtained. It can be seen that this dependence is a piecewise linear function with angular coefficients in the intervals

from 0 mm to 215 mm - ~ 0.016,

from 215 mm to 286 mm - ~ 0.028,

from 286 mm to 360 mm - ~ 0.032,

from 360 mm to 430 mm - ~ 0.047.

Thus, the implementation of the four conductive tracks 1 two-wire and the branching of the tap-off element 2 into four branches 3, equipped with rectangular bends with metal plates 4 placed at their ends, ensures the reliability of the broadband transition. The introduction of two contiguous metal rings 10 and 11 in contact with the rotating contact 7 ensures its reliability and the possibility of repeated rotation (long-term use). As can be seen from Fig.5, in the operating frequency band 617...960 MHz VSWR does not exceed the value of 1.4.

The main dimensions of the proposed device are: length ~ 600 mm, width is about ~ 450 mm.

Claims (7)

1. A power divider with a phase shifter for a base station antenna, containing concentric relative to the central point, arcuately arranged conductive tracks in the form of strip sections with an even number of emitters, as well as a tap element with non-contact transitions to conductive tracks and with the possibility of rotation around the center, characterized in that that the number of conductive tracks in the form of strip sections is four and they are made two-wire on the inside of the printed circuit board, and the tap-off element is made on the outside of the second printed circuit board, adjacent close to the inside of the first one, and the thickness of the second printed circuit board is three times less than the thickness of the first one, and is provided with four branches parallel to the arcuate conductive paths with a width of approximately 1/10 of the width of the two-wire conductive paths remote from the center of the conductors and with the possibility of movement along them, for which a rotating contact is installed in the center of rotation of the tap-off element, the ends of the branches are equipped with rectangular bends, at the ends of which metal plates are fixed, located above the conductors of the two-wire conductive tracks closest to the center. 2. A power divider with a phase shifter for a base station antenna according to claim 1, characterized in that the rotating contact is made in the form of two contacting concentric metal rings located on the internal contacting sides of the printed circuit boards, and contains coaxial metallized holes with fastening for pressing the printed circuit boards each to each other and reliability of contact of contiguous metal rings in contact. 3. A power divider with a phase shifter for the base station antenna according to claim 1, characterized in that the dependence of the width of the impedance transformer on the longitudinal coordinate is a piecewise linear function with slope coefficients in between from 0 mm to 215 mm - ~ 0.016, from 215 mm to 286 mm - ~ 0.028, from 286 mm to 360 mm - ~ 0.032, from 360 mm to 430 mm - ~ 0.047.

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