A phase shifter, an integrated feeding network, and a base station antenna

Abstract

The present invention relates to the technical field of antennas, and particularly relates to a phase shifter, an integrated feeding network and a base station antenna. The phase shifter includes a first dielectric plate and a second dielectric plate; on one side of the first dielectric plate, a first microstrip line is provided; the first microstrip line includes two parallel portions with flush ends and a connecting portion, the two parallel portions are arranged in parallel, and two ends of the connecting portion are respectively connected to the ends on the same side of the two parallel portions; on one side of the second dielectric plate, a second microstrip line is provided; the second microstrip line includes two slow-wave microstrip transmission lines with flush ends; the two slow-wave microstrip transmission lines are arranged in parallel and overlap with the parallel portions, so that the first microstrip line and the second microstrip line are electrically coupled; the first dielectric plate and the second dielectric plate are stacked and can slide relative to each other along the direction of the second microstrip line; the present invention also provides an integrated feeding network and a base station antenna. The present invention can reduce the volume of the phase shifter, which is beneficial to the integration of the feeding network in a narrow size and realizes the miniaturization of the base station antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, and particularly relates to a phase shifter, an integrated feeding network, and a base station antenna. Background Art

[0002] With the rapid development of the antenna industry, base station antennas are widely used. Currently, in the design of phase shifters for base station antennas, especially electrically tunable base station antennas, miniaturized phase shifters that are easy to integrate with the feeding network are widely used. And how to further reduce the volume of the phase shifter is beneficial to the integration of the feeding network with the phase shifter in a narrow size, meeting the design requirements of the feeding network and the base station antenna with a compact structure, which has become a technical problem that urgently needs to be solved. Summary of the Invention

[0003] The purpose of the present invention is to provide a phase shifter, an integrated feeding network, and a base station antenna to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] In a first aspect, an embodiment of the present invention provides a phase shifter, including: a first dielectric plate and a second dielectric plate;

[0006] One side of the first dielectric plate is provided with a first microstrip line; the first microstrip line includes two parallel portions with flush ends and a connecting portion, the two parallel portions are arranged in parallel, and both ends of the connecting portion are respectively connected to the ends on the same side of the two parallel portions;

[0007] One side of the second dielectric plate is provided with a second microstrip line; the second microstrip line includes two slow-wave microstrip transmission lines with flush ends; the two slow-wave microstrip transmission lines are arranged in parallel and overlap with the parallel portions, so that the first microstrip line and the second microstrip line are electrically coupled;

[0008] The first dielectric plate and the second dielectric plate are stacked and can slide relative to the second dielectric plate along the direction of the second microstrip line.

[0009] As a further improvement of the above technical solution, the first microstrip line has a U-shaped structure, that is, two parallel portions with flush ends and a connecting portion are connected to form a U-shaped structure.

[0010] As a further improvement of the above technical solution, the phase shifter further includes a grounding metal sheet, and the first dielectric plate is fixedly arranged at the top of the grounding metal sheet.

[0011] As a further improvement of the above technical solution, the slow-wave microstrip transmission line includes a plurality of slow-wave structures, two adjacent slow-wave structures are arranged in opposite directions, and are connected end to end through the other end of the bending portion.

[0012] As a further improvement of the above technical solution, the slow-wave structure includes an impedance matching portion, and the following are symmetrically arranged on the left and right sides of the impedance matching portion:

[0013] A straight portion, a first open-circuit stub is arranged at the top of the straight portion, the first open-circuit stub is perpendicular to the straight portion and faces a side opposite to the impedance matching portion;

[0014] A bending portion, one end of the bending portion connected to the impedance matching portion is arranged at the bottom of the straight portion and is parallel to the first open-circuit stub, and the other end of the bending portion is arranged in parallel with the straight portion;

[0015] Wherein, the straight portions symmetrically arranged on the left and right sides of the impedance matching portion form a first slot coupling region.

[0016] As a further improvement of the above technical solution, second open-circuit stubs are arranged at the corners of the bending portion in the slow-wave structure, and the second open-circuit stubs are parallel to the first open-circuit stubs;

[0017] The bending portions symmetrically arranged on the left and right sides of the impedance matching portion form a second slot coupling region;

[0018] The second open-circuit stub and the first open-circuit stub in the adjacent slow-wave structure form a third slot coupling region, the second open-circuit stub and the first open-circuit stub in the adjacent slow-wave structure have the same width and are aligned at both ends.

[0019] In a second aspect, an embodiment of the present invention further provides an integrated feeding network, including: a phase shifter according to any one of the first aspects and a transmission line connected to the phase shifter, and the transmission line is a slow-wave microstrip transmission line according to any one of the first aspects.

[0020] In a third aspect, an embodiment of the present invention further provides a base station antenna, including: an integrated feeding network according to any one of the second aspects.

[0021] The beneficial effects of the present invention are as follows: The present invention discloses a phase shifter, an integrated feeding network and a base station antenna. The phase shifter includes a first dielectric plate and a second dielectric plate; the phase shift amount of the phase shifter is changed by changing the coupling path length between the first microstrip line and the second microstrip line. The first microstrip line adopts two parallel portions, and the second microstrip line adopts two slow-wave microstrip transmission lines, which can reduce the volume of the phase shifter, facilitate the integration of the feeding network with the phase shifter in a narrow size, and meet the design requirements of a feeding network and a base station antenna with a compact structure. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is the overall schematic diagram of the phase shifter in the embodiment of the present invention;

[0024] Figure 2 is the cross-sectional schematic diagram of the phase shifter in the embodiment of the present invention;

[0025] Figure 3 is the coupling path schematic diagram of the first microstrip line and the second microstrip line in the embodiment of the present invention;

[0026] Figure 4 is the schematic diagram of the slow-wave structure in the embodiment of the present invention;

[0027] Figure 5 is the schematic diagram of another slow-wave structure in the embodiment of the present invention;

[0028] Figure 6 is Figure 5 the schematic diagram of the microstrip transmission line formed by the slow-wave structure shown;

[0029] Figure 7 is the schematic diagram of the structural comparison of the phase shifter before and after improvement in the embodiment of the present invention;

[0030] Figure 8 is the schematic diagram of the change in the phase shift amount when the first dielectric plate and the second dielectric plate slide relative to each other in the present invention;

[0031] Figure 9 is the schematic diagram of the voltage standing wave ratio when the first dielectric plate and the second dielectric plate slide relative to each other in the present invention;

[0032] Figure 10 is the comparison schematic diagram of the traditional transmission line and the microstrip transmission line in the present invention;

[0033] Figure 11 is Figure 10 the comparison diagram of the voltage standing wave ratio of the traditional transmission line and the microstrip transmission line in the present invention;

[0034] Figure 12 is Figure 10 the comparison diagram of the phase characteristic results of the traditional transmission line and the microstrip transmission line in the present invention;

[0035] Figure 13 is Figure 10Comparison diagram of the characteristic changes of the voltage standing wave ratio when the length of the traditional transmission line in [country] and the microstrip transmission line in the present invention remains unchanged and the longitudinal height H1 is changed;

[0036] Figure 14 is Figure 10 Comparison diagram of the phase characteristics when the length of the traditional transmission line in [country] and the microstrip transmission line in the present invention remains unchanged and the longitudinal height H1 is changed; Specific embodiments

[0037] This part will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the drawings. The function of the drawings is to supplement the description of the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be construed as a limitation on the protection scope of the present invention.

[0038] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0039] In the description of the present invention, if there are descriptions with words such as "several", its meaning is one or more, and the meaning of multiple is more than two. Understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number.

[0040] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0041] Refer to Figure 1 、 Figure 2 and Figure 3 According to [references], the embodiments of the present invention provide a phase shifter, and the phase shifter includes: a first dielectric plate 100 and a second dielectric plate 200;

[0042] One side of the first dielectric plate 100 is provided with a first microstrip line 110; the first microstrip line 110 includes two parallel portions 111 with flush ends and a connecting portion 112. The two parallel portions 111 are arranged in parallel, and the two ends of the connecting portion 112 are respectively connected to the ends on the same side of the two parallel portions 111;

[0043] On one side of the second dielectric plate 200, a second microstrip line 201 is provided; the second microstrip line 201 includes two slow-wave microstrip transmission lines 202 with flush ends; the two slow-wave microstrip transmission lines 202 are arranged in parallel and overlap with the parallel portion 111, so that the first microstrip line 110 and the second microstrip line 201 are electrically coupled;

[0044] The first dielectric plate 100 and the second dielectric plate 200 are stacked and can slide relative to the second dielectric plate 200 along the direction of the second microstrip line 201.

[0045] As Figure 3 shown, the design principle of the present invention is to change the phase shift amount of the phase shifter by changing the coupling path length between the first microstrip line 110 and the second microstrip line 201 (i.e., Figure 3 the size of X in

[0046] Specifically, keeping the position of the first dielectric plate 100 unchanged, by sliding the second dielectric plate 200 along the direction of the second microstrip line 201, the second microstrip line 201 is driven to slide, thereby changing the coupling path length (X) between the first microstrip line 110 and the second microstrip line 201, and thus changing the phase (phase shift amount) of the received and transmitted signals of the phase shifter.

[0047] In some embodiments, the first microstrip line 110 has a U-shaped structure, that is, two parallel portions 111 with flush ends and a connecting portion 112 are connected to form a U-shaped structure.

[0048] In some improved embodiments, the phase shifter further includes a grounding metal sheet 300, and the first dielectric plate 100 is fixedly arranged at the top of the grounding metal sheet 300.

[0049] The inventor found that using a high dielectric constant dielectric plate to miniaturize the phase shifter will increase the loss of the phase shifter; for this technical problem, the inventor further improves the second microstrip line 201 in the above embodiments, adopts a new slow-wave structure with a set characteristic impedance (such as a 50Ω characteristic impedance), and prints the microstrip line with the new slow-wave structure and the phase shift circuit on the same dielectric plate to realize an integrated miniaturized feeding network without a coaxial cable.

[0050] In some improved embodiments, the slow-wave microstrip transmission line 202 includes a plurality of slow-wave structures, and two adjacent slow-wave structures are arranged in opposite directions and are connected end to end through the other end of the bending portion 230.

[0051] Reference Figure 4 , in some improved embodiments, the slow-wave structure includes an impedance matching portion 210, and the left and right sides of the impedance matching portion 210 are symmetrically provided with:

[0052] The straight portion 220, a first open stub 221 is provided at the top of the straight portion 220, the first open stub 221 is perpendicular to the straight portion 220 and faces the side opposite to the impedance matching portion 210;

[0053] The bent portion 230, one end of the bent portion 230 connected to the impedance matching portion 210 is provided at the bottom of the straight portion 220 and is parallel to the first open stub 221, and the other end of the bent portion 230 is arranged in parallel with the straight portion 220;

[0054] Wherein, the straight portions 220 symmetrically arranged on the left and right of the impedance matching portion 210 form a first slot coupling region 222.

[0055] Reference Figure 5 and Figure 6 In some improved embodiments, second open stubs 231 are provided at the corners of the bent portion 230 in the slow wave structure, and the second open stubs 231 are parallel to the first open stubs 221;

[0056] The bent portions 230 symmetrically arranged on the left and right of the impedance matching portion 210 form a second slot coupling region 232;

[0057] The second open stub 231 and the first open stub 221 in the adjacent slow wave structure form a third slot coupling region 233, the second open stub 231 and the first open stub 221 in the adjacent slow wave structure have the same width and are aligned at both ends.

[0058] Reference Figure 7 From Figure 7 It can be seen that in the embodiments provided by the present invention, designing a slow wave structure with a set characteristic impedance in the phase shifter can further reduce the volume of the phase shifter. In the case of the same longitudinal length w, the phase shifter provided by the present invention can reduce the lateral length. And in the case of the same lateral length, the traditional structure of curved bending plus open stub requires a larger longitudinal dimension to achieve the same phase amount as the present invention.

[0059] Reference Figure 8 and Figure 9 , Figure 8 Shows the change in the phase shift amount corresponding to the movement of the U-shaped slider, Figure 9 Shows the voltage standing wave ratio of the phase shifter when the U-shaped slider moves. The test results show that the miniaturized phase shifter of the present invention can meet the impedance (50Ω characteristic impedance) matching of the ultra-wideband while satisfying the change in the phase shift amount.

[0060] The specific principle of the present invention is as follows: The slow-wave structure provided by the present invention aims to increase the total phase amount of the transmission line at the same transmission line length by reducing the phase velocity of the transmission line, thereby achieving the purpose of shortening the length of the transmission line. The phase velocity of the transmission line is determined by formula (1):

[0061]

[0062] where v 0 is the phase velocity, L is the equivalent inductance, and C is the equivalent capacitance; it can be seen that by increasing the equivalent inductance L and equivalent capacitance C in the slow-wave structure, the physical length of the transmission line can be shortened.

[0063] On the other hand, the characteristic impedance of the transmission line is calculated by formula (2):

[0064]

[0065] where Z 0 is the characteristic impedance of the transmission line. Therefore, in order to make the transmission line meet the required characteristic impedance (for example, Z 0 = 50 Ω) while shortening the physical length, it is necessary to simultaneously satisfy the distributed inductance L and distributed capacitance C required in formula (2) when designing the slow-wave structure.

[0066] To this end, the slow-wave structure provided by the present invention adopts a combination of a curved bending portion 230 and a straight portion 220 loaded with a first open stub 221 to achieve the distributed inductance L and distributed capacitance C required in formula (2).

[0067] In addition, the present invention provides an impedance matching portion 210 with low impedance characteristics between two adjacent first open stubs 221, which not only improves the power tolerance performance of the slow-wave structure but also further reduces the coupling between two adjacent first open stubs 221 and weakens the overall dispersion characteristics of the slow-wave structure.

[0068] Compared with a conventional microstrip transmission line, in the case of the same transverse length, the present invention can achieve the same phase amount as the conventional microstrip transmission line with a smaller longitudinal size by using a combination of multiple such slow-wave structures.

[0069] By adding a second open stub 231 at the corner of the curved bending portion 230, the present invention can not only make the overall distributed capacitance C and distributed inductance L in the entire microstrip transmission line reach a suitable ratio to meet the requirements of formula 2, but also further increase the total phase amount of the transmission line, making the phase characteristics of the curved bending portion 230 and the straight portion 220 loaded with the first open stub 221 tend to be similar.

[0070] In addition, this design can also reduce the gap coupling strength between the first open stub 221 and the curved bending portion 230 in the microstrip transmission line, thereby reducing the stray capacitance in the microstrip transmission line and weakening the dispersion characteristics, avoiding excessive difference in the phase quantity characteristics between the curved bending portion 230 and the first open stub 221, and reducing the gap coupling between the first open stub 221 and the curved bending portion 230.

[0071] In addition, an impedance matching portion 210 with low impedance characteristics is provided between two adjacent second open stubs 231 in the present invention, which not only improves the power tolerance performance of the slow-wave structure, but also further reduces the coupling between two adjacent second open stubs 231 and weakens the overall dispersion characteristics of the slow-wave structure.

[0072] Reference Figures 10 to 14 , Figure 10 In the upper left figure is a schematic diagram of a traditional transmission line, and in the lower left figure is a schematic diagram of the microstrip transmission line in the present invention. L1 is the horizontal length of the overall transmission line of the microstrip transmission line in the present invention; when the present invention uses a microstrip transmission line with a slow-wave structure to keep Figure 10 L1 in unchanged, that is, the widths of the straight portion 220, the first open stub 221, the bending portion 230, the first gap coupling region 222, the second open stub 231, the second gap coupling region 232, the three-gap coupling region 233, and the width of the curved bending line remain unchanged, only by adjusting the size of the overall longitudinal height H1 of the slow-wave structure used in the present invention, it is possible to increase the total phase amount while the microstrip transmission line always meets the requirement of a set characteristic impedance (such as a 50Ω characteristic impedance).

[0073] It can be seen that the slow-wave structure and the corresponding microstrip transmission line provided by the present invention can change the total phase delay while ensuring that the standing wave ratio of the transmission line is <1.1 by only changing the overall longitudinal width of the transmission line while keeping the transmission line length and the relative central position unchanged. In addition, the present invention can achieve different phase delay amounts by only changing the overall longitudinal height of the line while ensuring the standing wave ratio, which greatly simplifies the design of the miniaturized U-shaped slider phase shifter under different size requirements. The present invention realizes the miniaturized design of the phase shifter, reduces the material cost, and is more conducive to the integration of the phase shifter with the feeding network in a narrow size.

[0074] The embodiment of the present invention further provides an integrated feeding network, including: the phase shifter described in any one of the above embodiments and a transmission line connected to the phase shifter, and the transmission line is the slow-wave microstrip transmission line described in any one of the above embodiments.

[0075] The integrated feed network of the present invention applies the above-mentioned phase shifter. Therefore, the integrated feed network also has all the beneficial effects of the phase shifter. Also, due to the use of the slow-wave microstrip transmission line provided by the embodiments of the present invention, compared with conventional transmission lines, the size of the integrated feed network can be further reduced.

[0076] An embodiment of the present invention further provides a base station antenna, including: the integrated feed network described in any of the above embodiments.

[0077] The integrated feed network of the present invention applies the above-mentioned phase shifter, and the base station antenna applies this integrated feed network. Therefore, the base station antenna also has all the beneficial effects of the above-mentioned phase shifter and feed network, which will not be elaborated here.

[0078] Although the description of the present invention has been quite detailed and several of the described embodiments have been described in particular, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but rather should be regarded as effectively covering the intended scope of the present invention by referring to the appended claims and considering the broadest possible interpretation of these claims in view of the prior art. In addition, the present invention has been described above in terms of embodiments foreseeable by the inventors for the purpose of providing a useful description, and non-substantive modifications to the present invention that are not currently foreseeable may still represent equivalent modifications of the present invention.

Claims

1. A phase shifter, characterized in that, it includes: a first dielectric plate and a second dielectric plate; One side of the first dielectric plate is provided with a first microstrip line; the first microstrip line includes two parallel portions with flush ends and a connecting portion, the two parallel portions are arranged in parallel, and both ends of the connecting portion are respectively connected to the ends on the same side of the two parallel portions; One side of the second dielectric plate is provided with a second microstrip line; the second microstrip line includes two slow-wave microstrip transmission lines with flush ends; the two slow-wave microstrip transmission lines are arranged in parallel and overlap with the parallel portions, so that the first microstrip line and the second microstrip line are electrically coupled; The first dielectric plate and the second dielectric plate are stacked and can slide relative to the second dielectric plate along the direction of the second microstrip line; The slow-wave microstrip transmission line includes a plurality of slow-wave structures, and the slow-wave structure includes an impedance matching portion, and the left and right sides of the impedance matching portion are symmetrically provided with: a straight portion, the top of the straight portion is provided with a first open-circuit stub, the first open-circuit stub is perpendicular to the straight portion and faces the side opposite to the impedance matching portion; a bent portion, one end of the bent portion connected to the impedance matching portion is arranged at the bottom of the straight portion and is parallel to the first open-circuit stub, and the other end of the bent portion is arranged in parallel with the straight portion; Wherein, the straight portions symmetrically arranged on the left and right sides of the impedance matching portion form a first slot coupling region; Two adjacent slow-wave structures are arranged in opposite directions and are connected end to end through the other end of the bent portion.

2. A phase shifter according to claim 1, characterized in that, The first microstrip line has a U-shaped structure, that is, two parallel portions with flush ends and a connecting portion are connected to form a U-shaped structure.

3. A phase shifter according to claim 1, characterized in that, The phase shifter further includes a grounding metal sheet, and the first dielectric plate is fixedly arranged at the top end of the grounding metal sheet.

4. A phase shifter according to claim 1, characterized in that, Second open-circuit stubs are arranged at the corners of the bent portions in the slow-wave structure, and the second open-circuit stubs are parallel to the first open-circuit stubs; The bent portions symmetrically arranged on the left and right sides of the impedance matching portion form a second slot coupling region; The second open-circuit stub and the first open-circuit stub in the adjacent slow-wave structure form a third slot coupling region, the second open-circuit stub and the first open-circuit stub in the adjacent slow-wave structure have the same width and are aligned at both ends.

5. An integrated feed network, characterized in that, it includes: The phase shifter according to any one of claims 1 to 4 and a transmission line connected to the phase shifter, and the transmission line is the slow-wave microstrip transmission line according to any one of claims 1 to 4.

6. A base station antenna, characterized in that, it includes: The integrated feed network according to claim 5.

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