Ultra-wideband low-pass phase shifter

Abstract

The application discloses a kind of ultra-wideband low-pass phase shifters, including phase shift unit, low-pass filter unit, output interface and input interface;The phase shift unit includes rotary power distribution module, short-circuit stub matching module, phase shift track and fixed assembly.The low-pass filter unit is constituted by multiple filter branches, integrated between input port and phase shift unit, the short-circuit stub matching module includes two short-circuit stubs, and is connected at the branch where the output interface is located at the concentric circle center with phase shift unit.This application has excellent adaptability in base station antenna low frequency band, meets the market demand of low loss, high integration, when applied to batch production of base station antenna, simplify product while improving the efficiency and power tolerance of antenna and other performances.

Description

Technical Field

[0001] This invention relates to phase shifters for base station antennas, and more specifically to low-frequency ultra-wideband low-pass phase shifters for base station antennas. Background Technology

[0002] With the development and popularization of mobile communication in China over the past few decades, the breadth and depth of network coverage have reached a fairly high level. Mutual suppression between different frequency bands has long been an important technical indicator for base station antennas. A large number of multi-band base station antennas need to add filters at the port. The filters usually need to be connected between the phase shifter and the antenna interface through coaxial cables, which greatly increases the antenna assembly process and manufacturing cost. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide an ultra-wideband low-pass phase shifter that integrates the filter of a multi-frequency antenna onto the phase shifter, thereby simultaneously realizing phase shifting and low-pass filtering functions, simplifying the antenna while improving its efficiency and power tolerance.

[0004] Technical solution: To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0005] An ultra-wideband low-pass phase shifter includes a phase shifting unit, a low-pass filter unit, an output interface, and an input interface. The phase shifting unit includes a rotary power distribution module, a short-circuit stub matching module, a phase shifting track, and a fixing component. The low-pass filter unit consists of multiple filter sections integrated between the phase shifting unit and the input interface. The short-circuit stub matching module includes two short-circuit stubs, which are located on the branch where the output interface is located, connected to the center of the concentric circle of the phase shifting unit.

[0006] Preferably, the phase-shifting track is a concentric circular arc microstrip line with different radii, and a rotary power distribution module is installed on the concentric circular arc microstrip line. The rotary power distribution module rotates with the center of the concentric circle of the phase-shifting track as the reference, and each output interface obtains an arithmetic sequence phase.

[0007] Preferably, the rotary power distribution module consists of power distribution lines and a power distribution substrate, with the power distribution lines attached to the power distribution substrate.

[0008] Preferably, the phase-shifting track includes a first track and a second track, wherein the first track and the second track are concentric at the center of a concentric circle and are attached to the substrate.

[0009] Preferably, the fixing component includes a screw, a nut, a clip, and a rigid spring.

[0010] Preferably, the rigid spring is made of shape memory steel and has an L-shaped shape. One end is fixed to the center of the concentric circle of the track by a screw and nut to provide downward pressure to the other end, so as to achieve a tight fit between the substrate and the power distribution substrate.

[0011] Preferably, the plurality of filter segments are two, three, or five filter segments, which are used to implement second-order, third-order, or fifth-order low-pass microstrip filters, respectively.

[0012] Preferably, the filter segment is L-shaped or rectangular.

[0013] Preferably, the output interface includes a first output interface, a second output interface, a third output interface, a fourth output interface, and a fifth output interface. The first output interface and the fifth output interface are distributed at both ends of the first track, the second output interface and the fourth output interface are distributed at both ends of the second track, and the third output interface is distributed at the end of the branch connected to the center of the concentric circle.

[0014] Beneficial Effects: The ultra-wideband low-pass phase shifter provided by this invention features a rotating power distribution module that rotates around the center of the concentric circles of the phase shift track. Chebyshev weighting is achieved at each output port through surface power distribution circuitry. A microstrip low-pass filter is integrated at the input interface, effectively suppressing signals in the intermediate frequency band of the base station antenna. Furthermore, a short-circuit stub matching stub is integrated, improving the resonant matching degree of the phase shifter, resulting in a more convergent matching state at the input interface, and making the amplitude distribution of each output interface closer to Chebyshev weighting. Compared with existing technologies, the ultra-wideband low-pass phase shifter of this invention exhibits excellent matching characteristics in the low-frequency band of the base station antenna, good suppression of signals in other frequency bands, more stable power distribution, superior heat treatment capabilities, and lower losses. Its structure and manufacturing process meet the market demands for lightweight and highly integrated designs, reducing costs while improving product performance when applied to mass production of base station antennas. Attached Figure Description

[0015] Figure 1 This is an exploded view of an embodiment of the present invention.

[0016] Figure 2 This is a front view of an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the back side of an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of a rotary power distribution module in an embodiment of the present invention.

[0019] Figure 5 This is a graph showing the input port-output port S21 (dB) curves in an embodiment of the present invention.

[0020] Figure 6 The input port return loss S11 (dB) curve is shown in this embodiment of the invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1-4 As shown in the figure, an ultra-wideband low-pass phase shifter disclosed in this invention mainly includes a phase shifting unit, a low-pass filtering unit, an output interface, and an input interface. The phase shifting unit comprises a rotating power distribution module, a short-circuit stub matching module, a phase shifting track, and a fixing component. The phase shifting track is a concentric circular arc microstrip line with different radii. A rotating power distribution module is mounted on the concentric circular arc microstrip line, rotating around the center of the concentric circle of the phase shifting track, resulting in an arithmetic sequence phase for each output port. The rotating power distribution module achieves Chebyshev weighting for each output port through surface power distribution lines. The short-circuit stub matching module is located on the branch where the output interface is located, connected to the center of the concentric circle of the phase shifting unit. The low-pass filtering unit consists of multiple filtering sections integrated between the phase shifting unit and the input interface, and can suppress signals in the intermediate frequency band of the base station antenna.

[0023] The rotary power distribution module includes a power distribution line 702 and a power distribution substrate 701, with the power distribution line 702 attached to the power distribution substrate 701. The phase-shifting track includes a first track 1 and a second track 2, which are concentrically located at the center 8 of a concentric circle and are attached to the substrate 10. A first output interface 1101 and a fifth output interface 1105 are distributed at both ends of the first track 1; a second output interface 1102 and a fourth output interface 1104 are distributed at both ends of the second track 2; and a third output interface 1103 is distributed at the end of a branch connected to the center 8 of the concentric circle.

[0024] like Figure 2-4As shown, the power distribution line 702 is fixed to the base plate 10 by screw 1201, nut 1202, rigid spring 13 and buckle 14. The rigid spring 13 is made of memory steel and has an L-shaped shape. One end is fixed to the center 8 of the concentric circle of the track by screw 1201 and nut 1202 to provide downward pressure to the other end. The three tightly fixed points are three strong coupling power supply links between the power distribution line 702 and the first track 1, the second track 2 and the input interface 3. The radius of the first track 1 is twice the radius of the second track 2. When the power distribution line 702 rotates around the center 8 of the concentric circle of the track, the distance that the power distribution line 702 moves on the first track 1 is twice that on the second track 2. Accordingly, from the perspective of the complete phase shifter link, the input interface 3 to the first output interface 1101, the second output interface 1102, the third output interface 1103, the fourth output interface 1104, and the fifth output interface 1105 will form an arithmetic sequence phase distribution similar to 2X°, X°, 0°, -X°, -2X°, thus realizing the electronic tilt angle of the antenna.

[0025] like Figure 2 As shown, the short-circuit stub matching module consists of two short-circuit stubs 9. The two short-circuit stubs 9 are distributed in the branch where the third output interface 1103 is located. On the one hand, the dual short-circuit matching improves the matching degree of the phase shifter. On the other hand, the wires of the short-circuit stubs 9 are made of metal, which can transfer the heat generated by the phase shifter loss to the large area of ​​metal-coated surface on the back of the substrate 10, greatly improving the power tolerance of the phase shifter.

[0026] The low-pass filter unit is integrated between the phase shifter unit and the input interface 3, and consists of a first filter branch 4, a second filter branch 5, and a third filter branch 6. The first filter branch 4, the second filter branch 5, and the third filter branch 6, together with the substrate 10, form a third-order low-pass microstrip filter link. The order of the filter is not limited to the third order in this embodiment; the integration of second-order and fifth-order filters also falls within the protection scope of the ultra-wideband low-pass phase shifter of this invention.

[0027] Figure 5 and 6 Performance parameter curves of a specific phase shifter designed according to an embodiment of the present invention are provided. As shown in the figure, the phase shifter designed in this invention exhibits excellent return loss of <-25dB across the entire low-frequency band of the base station antenna, including 600MHz, 700MHz, 800MHz, and 900MHz. The power distribution from the input port to each output port can be controlled within a fluctuation range of less than 0.5dB. It also demonstrates excellent suppression performance in the mid-frequency band of the base station antenna, including 1700MHz, 1800MHz, 1900MHz, 2000MHz, 2100MHz, 2200MHz, 2300MHz, 2400MHz, 2500MHz, and 2600MHz.

[0028] The above embodiments are specific implementations of the ultra-wideband low-pass phase shifter of the present invention, described in detail. Although several implementations are covered, they are not intended to limit the scope of protection of the present invention. In the field of base station antennas, any modifications and improvements made without departing from the design concept of the present invention should fall within the scope of protection of the ultra-wideband low-pass phase shifter of the present invention.

Claims

1. An ultra-wideband low-pass phase shifter, characterized in that, The device includes a phase-shifting unit, a low-pass filter unit, an output interface, and an input interface. The phase-shifting unit includes a rotary power distribution module, a short-circuit stub matching module, a phase-shifting track, and a fixing component. The low-pass filter unit consists of multiple filter sections and is integrated between the phase-shifting unit and the input interface. The short-circuit stub matching module includes two short-circuit stubs, which are located on the branch where the output interface is located, and are connected to the center of the concentric circle of the phase-shifting unit. This module is used to improve the matching degree of the phase shifter and to transfer the heat generated by the phase shifter's losses to the metal-clad surface on the back of the substrate.

2. The ultra-wideband low-pass phase shifter according to claim 1, characterized in that, The phase-shifting track is a concentric circular arc microstrip line with different radii. A rotary power distribution module is installed on the concentric circular arc microstrip line. The rotary power distribution module rotates with the center of the concentric circle of the phase-shifting track as the reference, and each output interface obtains an arithmetic sequence phase.

3. The ultra-wideband low-pass phase shifter according to claim 1, characterized in that, The rotary power distribution module consists of power distribution lines and a power distribution substrate, with the power distribution lines attached to the power distribution substrate.

4. The ultra-wideband low-pass phase shifter according to claim 1, characterized in that, The phase-shifting track includes a first track and a second track, which are concentric at the center of a concentric circle and are attached to the substrate.

5. The ultra-wideband low-pass phase shifter according to claim 1, characterized in that, The fixing components include screws, nuts, clips, and rigid springs.

6. The ultra-wideband low-pass phase shifter according to claim 5, characterized in that, The rigid spring is made of shape memory steel and is L-shaped. One end is fixed to the center of the concentric circle of the track by a screw and nut, which provides downward pressure to the other end, so as to achieve a tight fit between the substrate and the power distribution substrate.

7. The ultra-wideband low-pass phase shifter according to claim 1, characterized in that, The plurality of filter segments are two, three, or five filter segments, which are used to implement second-order, third-order, or fifth-order low-pass microstrip filters, respectively.

8. The ultra-wideband low-pass phase shifter according to claim 1, characterized in that, The filter section is L-shaped or strip-shaped rectangle.

9. The ultra-wideband low-pass phase shifter according to claim 4, characterized in that, The output interface includes a first output interface, a second output interface, a third output interface, a fourth output interface, and a fifth output interface. The first output interface and the fifth output interface are located at both ends of the first track, the second output interface and the fourth output interface are located at both ends of the second track, and the third output interface is located at the end of the branch connected to the center of the concentric circle.

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