Waveguide conversion device and wireless communication system

Abstract

The present disclosure provides a waveguide conversion device and a wireless communication system, and belongs to the technical field of microwaves, and can solve the waveguide conversion problem. The waveguide conversion device comprises a waveguide cavity, a waveguide transmission cavity and a waveguide back cavity which are oppositely arranged; a substrate is arranged between the waveguide transmission cavity and the waveguide back cavity; the substrate comprises at least a first substrate; a conversion module is arranged on the first substrate, and the conversion module comprises a balanced antenna, a first differential strip line and a second differential strip line, wherein the balanced antenna is arranged in the area opposite to the waveguide transmission cavity and the waveguide back cavity, and the balanced antenna is provided with a first output end and a second output end; the first end of the first differential strip line is connected with the first output end of the balanced antenna; and the first end of the second differential strip line is connected with the second output end of the balanced antenna. The present disclosure can realize the connection and mode conversion problem from the waveguide to the microstrip differential line.

Description

Technical Field

[0001] This disclosure belongs to the field of microwave technology, specifically relating to a waveguide conversion device and a wireless communication system. Background Technology

[0002] Wireless communication systems are gradually developing towards miniaturization, integration, and multi-functionality. Waveguide-differential microstrip line conversion devices have become an important component of various wireless communication systems. Moreover, the performance of waveguide-differential microstrip line conversion devices directly affects the performance of wireless communication systems. For example, waveguide-differential microstrip line conversion devices affect the integration density of low-profile planar circuits and the anti-interference capability of wireless communication systems. Summary of the Invention

[0003] This disclosure aims to provide a waveguide conversion device and a wireless communication system.

[0004] The first aspect of this disclosure provides a waveguide conversion device, comprising:

[0005] A waveguide cavity, comprising a waveguide transmission cavity and a waveguide back cavity disposed opposite to each other;

[0006] A substrate is disposed between the waveguide transmission cavity and the waveguide back cavity; the substrate includes at least a first substrate.

[0007] A conversion module is disposed on the first substrate. The conversion module includes a balanced antenna, a first differential stripline, and a second differential stripline. The balanced antenna is disposed in the region opposite to the waveguide transmission cavity and the waveguide back cavity. The balanced antenna has a first output terminal and a second output terminal. The first end of the first differential stripline is connected to the first output terminal of the balanced antenna, and the first end of the second differential stripline is connected to the second output terminal of the balanced antenna.

[0008] The balanced antenna includes a first antenna section and a second antenna section symmetrically arranged, the first antenna section and the second antenna section are connected by an antenna connection section, the first output terminal is disposed on the first antenna section, and the second output terminal is disposed on the second antenna section.

[0009] Wherein, the projections of the first antenna portion and the second antenna portion onto the first substrate are both right-angled triangles, and the acute angle portion of the first antenna portion and the acute angle portion of the second antenna portion are connected through the antenna connecting portion;

[0010] Alternatively, the projections of the first antenna portion and the second antenna portion onto the first substrate are both isosceles or equilateral triangles, and the apex of the first antenna portion and the apex of the second antenna portion are connected by the antenna connection portion.

[0011] Alternatively, the projections of the first antenna portion and the second antenna portion onto the first substrate are both rectangular, and the short side of the first antenna portion and the short side of the second antenna portion are connected through the antenna connection portion.

[0012] The conversion module further includes a balancing stub, which is connected to the antenna connection portion and located between the first differential stripline and the second differential stripline.

[0013] The substrate further includes a second substrate, which is stacked on top of the first substrate and located near the back cavity of the waveguide; the conversion module is disposed between the first substrate and the second substrate.

[0014] The balanced antenna is either a monopole antenna or a dipole antenna.

[0015] The waveguide conversion device further includes a ground plane, which is disposed below the surface of the second substrate adjacent to the waveguide back cavity, above the surface of the first substrate adjacent to the waveguide transmission cavity, or between the first substrate and the second substrate.

[0016] Wherein, the second end of the first differential stripline is connected to the first microstrip differential line, and the second end of the second differential stripline is connected to the second microstrip differential line.

[0017] The bottom of the waveguide back cavity is provided with a waveguide ridge.

[0018] The waveguide transmission cavity is provided with one or more ridge structures stacked sequentially.

[0019] The waveguide cavity includes any one of a rectangular waveguide cavity, a circular waveguide cavity, an elliptical waveguide cavity, and a ridge waveguide cavity.

[0020] A second aspect of this disclosure provides a wireless communication system, which includes a waveguide conversion device, wherein the waveguide conversion device employs the waveguide conversion device provided in the embodiments of this disclosure. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a waveguide conversion device provided in an embodiment of the present disclosure;

[0022] Figure 2 A side view of a waveguide conversion device provided in an embodiment of this disclosure;

[0023] Figure 3 This is a schematic diagram of the conversion module and microstrip differential line according to an embodiment of the present disclosure;

[0024] Figure 4This is a schematic diagram of another waveguide conversion device provided in an embodiment of the present disclosure;

[0025] Figure 5 A schematic diagram of another waveguide conversion device provided in this embodiment of the present disclosure;

[0026] Figure 6 A schematic diagram of another waveguide conversion device provided in this embodiment of the present disclosure;

[0027] Figure 7 A schematic diagram of another waveguide conversion device provided in this disclosure embodiment;

[0028] Figure 8 This is a schematic diagram of another waveguide conversion device provided in an embodiment of the present disclosure;

[0029] Figure 9 A simulation diagram of the S-feature of the waveguide conversion device provided in the embodiments of this disclosure.

[0030] The attached figures are labeled as follows:

[0031] 1-Waveguide cavity, 11-Waveguide transmission cavity, 111-Ridge structure, 12-Waveguide back cavity, 121-Waveguide ridge;

[0032] 2-Substrate, 21-First substrate, 22-Second substrate;

[0033] 3-Conversion module, 31-Balanced antenna, 31a-First antenna section, 31b-Second antenna section, 31c-Antenna connection section, 311-First output terminal, 312-Second output terminal, 32-First differential stripline, 33-Second differential stripline, 34-Ground floor, 35-Balanced stub;

[0034] 41 - First microstrip differential line, 42 - Second microstrip differential line. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0037] In a first aspect, embodiments of this disclosure provide a waveguide switching device that can connect a waveguide to a microstrip differential line and solve the mode conversion mismatch problem.

[0038] Figure 1 This is a schematic diagram of the structure of a waveguide conversion device provided in an embodiment of the present disclosure. Figure 2 This is a side view of a waveguide conversion device provided in an embodiment of this disclosure. Figure 1 and Figure 2 As shown, the waveguide conversion device includes a waveguide cavity 1, a substrate 2, and a conversion module 3.

[0039] The waveguide cavity 1 is used to constrain the transmission direction of electromagnetic waves. The waveguide cavity 1 includes a waveguide transmission cavity 11 and a waveguide back cavity 12 arranged opposite to each other, and the area opposite the waveguide transmission cavity 11 and the waveguide back cavity 12 is the feed port.

[0040] In some embodiments, waveguide cavity 1 is a rectangular waveguide cavity, that is, waveguide transmission cavity 11 and waveguide back cavity 12 are rectangular structures. Rectangular waveguide cavities have a wider fundamental mode bandwidth, which is beneficial for achieving mode matching over a wide frequency band.

[0041] In some embodiments, the height of the waveguide back cavity 12 is one-quarter of the waveguide wavelength, that is, the height of the waveguide back cavity 12 is λ / 4, where λ is the wavelength of the waveguide. This can improve the coupling efficiency of the waveguide, thereby improving the transmission efficiency of the waveguide, and thus improving the resonant frequency and bandwidth.

[0042] In this embodiment, the substrate 2 is disposed between the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the waveguide transmission cavity 11, the substrate 2 and the waveguide back cavity 12 are stacked in sequence.

[0043] In some embodiments, the substrate 2 includes at least a first substrate 21, and the waveguide transmission cavity 11 and the first substrate 21 can confine electromagnetic waves to the conversion module 3, thereby improving the coupling efficiency of the waveguide.

[0044] In this embodiment, the conversion module 3 is disposed on the first substrate 21, that is, the first substrate 21 carries the conversion module 3, and the mode conversion of the waveguide microstrip differential line is realized through the conversion module 3.

[0045] In some embodiments, the conversion module 3 includes a balanced antenna 31, a first differential stripline 32, and a second differential stripline 33. The balanced antenna 31 is disposed in the region opposite to the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, in the region opposite to the feed port. The balanced antenna 31 is provided with a first output terminal 311 and a second output terminal 312 for outputting differential signals. The first end of the first differential stripline 32 is connected to the first output terminal 311 of the balanced antenna 31, and the first end of the second differential stripline 33 is connected to the second output terminal 312 of the balanced antenna 31.

[0046] In some embodiments, the second end of the first differential stripline 32 is connected to the first microstrip differential line 41, that is, the first output terminal 311 of the balanced antenna 31 is connected to the first microstrip differential line 41 through the first differential stripline 32; the second end of the second differential stripline 33 is connected to the second microstrip differential line 42, that is, the second output terminal 312 of the balanced antenna 31 is connected to the second microstrip differential line 42 through the second differential stripline 33.

[0047] It should be noted that the first end and the second end of the first differential strip 32 do not define the positions of the two ends of the first differential strip 32, and the first end and the second end of the second differential strip 33 do not define the positions of the two ends of the second differential strip 33.

[0048] Figure 3 This is a schematic diagram of the conversion module and microstrip differential line according to an embodiment of this disclosure. Figure 1 and Figure 3 As shown, the balanced antenna 31 includes a first antenna section 31a and a second antenna section 31b symmetrically arranged. The first antenna section 31a and the second antenna section 31b are connected by an antenna connection section 31c. A first output terminal 311 is disposed on the first antenna section 31a, and a second output terminal 312 is disposed on the second antenna section 31b.

[0049] In some embodiments, the first antenna portion 31a and the second antenna portion 31b are both right-angled triangles projected onto the first substrate 21, and the acute angle portion of the first antenna portion 31a and the acute angle portion of the second antenna portion 31b are connected by the antenna connection portion 31c.

[0050] It should be noted that a right triangle has two acute angles, and these two acute angles can be the same or different. Correspondingly, the first antenna section 31a and the second antenna section 31b each have two acute angle sections, and the angles of these two acute angle sections can be the same or different.

[0051] For example, the first antenna section 31a includes a first acute-angled section and a second acute-angled section, the angle of the first acute-angled section being greater than or equal to the angle of the second acute-angled section. The second antenna section 31b includes a first acute-angled section and a second acute-angled section, the angle of the first acute-angled section being greater than or equal to the angle of the second acute-angled section. Specifically, the angle of the first acute-angled section of the first antenna section 31a is the same as the angle of the first acute-angled section of the second antenna section 31b, and the angle of the second acute-angled section of the first antenna section 31a is the same as the angle of the second acute-angled section of the second antenna section 31b, thus ensuring that the first antenna section 31a and the second antenna section 31b have a symmetrical structure.

[0052] It is understandable that the first acute angle and the second acute angle are only for the convenience of explaining the two acute angles of the first antenna section 31a and the second antenna section 31b, and are not intended to limit the position of the first acute angle and the second acute angle.

[0053] When the angles of the first acute angle portion and the second acute angle portion are different, the first antenna portion 31a and the second antenna portion 31b should be symmetrically connected, that is, the first acute angle portion of the first antenna portion 31a and the first acute angle portion of the second antenna portion 31b are connected through the antenna connection portion 31c, or the second acute angle portion of the first antenna portion 31a and the second acute angle portion of the second antenna portion 31b are connected through the antenna connection portion 31c; or the right angle portion of the first antenna portion 31a and the right angle portion of the second antenna portion 31b are connected through the antenna connection portion 31c.

[0054] In this embodiment, the balanced antenna 31 is a planar antenna, consisting of a symmetrically arranged first antenna section 31a and a second antenna section 31b connected together. To ensure tight coupling of the waveguide's fundamental mode, the direction in which the balanced antenna 31 is inserted into the waveguide cavity 1 can be adjusted according to the characteristics of the magnetic field distribution between the waveguide and the balanced antenna 31.

[0055] For example, when the waveguide cavity 1 is a rectangular waveguide cavity, the balanced antenna 31 is inserted into the waveguide cavity 1 from the narrow side of the rectangular waveguide cavity. This can make the electric field generated by the balanced antenna 31 consistent with the mode of the waveguide fundamental mode electric field, and can excite the fundamental mode of the waveguide.

[0056] It should be noted that the input impedance of the balanced antenna 31 is a function of the width and length of the balanced antenna 31, the height of the waveguide cavity 12, and the frequency. Adjusting the length, width, and height of the waveguide cavity 12 of the balanced antenna 31 can reduce the influence of frequency on the input impedance of the balanced antenna 31, meaning that the real and imaginary parts of the input impedance are essentially unaffected by frequency. By adjusting the length and width of the balanced antenna 31, the impedance of the balanced antenna 31 is made to have a real part of 50 ohms and an imaginary part, and the balanced antenna 31 is mode-matched with the first microstrip differential line 41 and the second microstrip differential line 42.

[0057] In this embodiment of the disclosure, the waveguide is connected to the first differential stripline 32 and the second differential stripline 33 through the balanced antenna 31, and mode matching between the balanced antenna 31 and the first microstrip differential line 41 and the second microstrip differential line 42 is achieved.

[0058] like Figure 1 and Figure 2 As shown, the substrate 2 also includes a second substrate 22, which is stacked with the first substrate 21, and the second substrate 22 is located on the side close to the waveguide back cavity 12. The conversion module 3 is disposed between the first substrate 21 and the second substrate 22, that is, the waveguide transmission cavity 11, the first substrate 21, the conversion module 3, the second substrate 22 and the waveguide back cavity 12 are stacked in sequence.

[0059] The conversion module 3 is disposed between the first substrate 21 and the second substrate 22. The first substrate 21 and the waveguide transmission cavity 11 can constrain the transmission of electromagnetic waves to the balanced antenna 31, and the second substrate 22 and the waveguide back cavity 12 can reduce the loss of electromagnetic waves.

[0060] In some embodiments, the balanced antenna 31 is a monopole antenna or a half-wave dipole antenna. Monopole antennas and half-wave dipole antennas are flexible in design, have a wide range of applications, and can use various types of waveguides.

[0061] When the balanced antenna 31 is a monopole antenna, such as Figure 1 and Figure 2 As shown, the waveguide conversion device 3 also includes a ground plane 34, which is grounded. The ground plane 34 is disposed on the side of the second substrate 22 near the waveguide back cavity 12, or the ground plane 34 is disposed on the side of the first substrate 21 near the waveguide transmission cavity 11, or it is disposed between the first substrate 21 and the second substrate 22.

[0062] In some embodiments, the width of the ground plane 34 is the same as that of the first substrate 21 and the second substrate 22, and the length of the ground plane 34 is less than the lengths of the first substrate 21 and the second substrate 22. The ground plane 34 is disposed outside the waveguide back cavity 12, that is, the ground plane 34 is not inserted between the waveguide transmission cavity 11 and the waveguide back cavity 12. In some embodiments, without affecting waveguide transmission, a portion of the ground plane 34 is inserted between the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, a portion of the ground plane 34 is inserted between the waveguide transmission cavity 11 and the waveguide back cavity 12.

[0063] Figure 4 This is a schematic diagram of another waveguide conversion device provided in an embodiment of this disclosure. Figure 4 As shown, the waveguide conversion device includes a waveguide cavity 1, a substrate 2, and a conversion module 3. The waveguide cavity 1 and the substrate 2 are connected to... Figure 1 and Figure 4 The waveguide conversion device shown is different in that it has conversion module 3. To save space, only the different parts will be introduced below.

[0064] The conversion module 3 includes a balanced antenna 31, a first differential stripline 32, and a second differential stripline 33. The balanced antenna 31 is disposed in the region opposite to the waveguide transmission cavity 11 and the waveguide back cavity 12, i.e., in the region opposite to the feed port. The balanced antenna 31 is provided with a first output terminal 311 and a second output terminal 312 for outputting differential signals. One end of the first differential stripline 32 is connected to the first output terminal 311 of the balanced antenna 31, and the other end is connected to the first microstrip differential line 41, i.e., the first output terminal 311 of the balanced antenna 31 is connected to the first microstrip differential line 41 through the first differential stripline 32; one end of the second differential stripline 33 is connected to the second output terminal 312 of the balanced antenna 31, and the other end is connected to the second microstrip differential line 42, i.e., the second output terminal 312 of the balanced antenna 31 is connected to the second microstrip differential line 42 through the second differential stripline 33.

[0065] In this embodiment of the present disclosure, the balanced antenna 31 includes a first antenna section 31a and a second antenna section 31b symmetrically arranged. The first antenna section 31a and the second antenna section 31b are connected by an antenna connection section 31c. A first output terminal 311 is disposed on the first antenna section 31a, and a second output terminal 312 is disposed on the second antenna section 31b.

[0066] In some embodiments, the projections of the first antenna portion 31a and the second antenna portion 31b onto the first substrate 21 are both isosceles triangles or equilateral triangles, and the apex of the first antenna portion 31a and the apex of the second antenna portion 31b are connected by an antenna connection portion 31c. Here, the apex is relative to the vertex of a triangle. For the first antenna portion 31a and the second antenna portion 31b projected as isosceles triangles, the apex corresponds to the vertex of the isosceles triangle. For the first antenna portion 31a and the second antenna portion 31b projected as equilateral triangles, the apex corresponds to any vertex of the equilateral triangle.

[0067] like Figure 4 As shown, after the top corner of the first antenna section 31a and the top corner of the second antenna section 31b are connected by the antenna connection section 31c, the shape of the projection of the balanced antenna 31 on the first substrate 21 is a bow-tie shape.

[0068] Figure 5 This is a schematic diagram of another waveguide conversion device provided in an embodiment of this disclosure. Figure 5 As shown, the waveguide conversion device includes a waveguide cavity 1, a substrate 2, and a conversion module 3. The waveguide cavity 1 and the substrate 2 are connected to... Figure 1 and Figure 4 The waveguide conversion device shown is different in that it has conversion module 3. To save space, only the different parts will be introduced below.

[0069] The conversion module 3 includes a balanced antenna 31, a first differential stripline 32, and a second differential stripline 33. The balanced antenna 31 is disposed in the region opposite to the waveguide transmission cavity 11 and the waveguide back cavity 12, i.e., in the region opposite to the feed port. The balanced antenna 31 is provided with a first output terminal 311 and a second output terminal 312 for outputting differential signals. One end of the first differential stripline 32 is connected to the first output terminal 311 of the balanced antenna 31, and the other end is connected to the first microstrip differential line 41, i.e., the first output terminal 311 of the balanced antenna 31 is connected to the first microstrip differential line 41 through the first differential stripline 32; one end of the second differential stripline 33 is connected to the second output terminal 312 of the balanced antenna 31, and the other end is connected to the second microstrip differential line 42, i.e., the second output terminal 312 of the balanced antenna 31 is connected to the second microstrip differential line 42 through the second differential stripline 33.

[0070] like Figure 5 As shown, the balanced antenna 31 includes a first antenna section 31a and a second antenna section 31b symmetrically arranged. The first antenna section 31a and the second antenna section 31b are connected by an antenna connection section 31c. A first output terminal 311 is disposed on the first antenna section 31a, and a second output terminal 312 is disposed on the second antenna section 31b.

[0071] In this embodiment, the projections of the first antenna portion 31a and the second antenna portion 31b onto the first substrate 21 are both rectangular, and the short side of the first antenna portion 31a and the short side of the second antenna portion 31b are connected by the antenna connecting portion 31c. After the short sides of the first antenna portion 31a and the short sides of the second antenna portion 31b are connected by the antenna connecting portion 31c, the projection of the balanced antenna 31 onto the first substrate 21 is rectangular.

[0072] Figure 6 This is a schematic diagram of another waveguide conversion device provided in an embodiment of this disclosure. Figure 6 As shown, the waveguide conversion device includes a waveguide cavity 1, a substrate 2, and a conversion module 3.

[0073] The waveguide cavity 1 is used to constrain the transmission direction of electromagnetic waves. The waveguide cavity 1 includes a waveguide transmission cavity 11 and a waveguide back cavity 12 arranged opposite to each other, and the area opposite the waveguide transmission cavity 11 and the waveguide back cavity 12 is the feed port.

[0074] In some embodiments, the waveguide cavity 1 is a rectangular waveguide cavity, that is, the waveguide transmission cavity 11 and the waveguide back cavity 12 are rectangular structures. In some embodiments, the height of the waveguide back cavity 12 is one-quarter of the waveguide wavelength, that is, the height of the waveguide back cavity 12 is λ / 4, where λ is the wavelength of the waveguide. This can improve the coupling efficiency of the waveguide, thereby improving the transmission efficiency of the waveguide, and thus improving the resonant frequency and bandwidth.

[0075] In some embodiments, a waveguide ridge 121 is provided at the bottom of the waveguide back cavity 12. The waveguide ridge 121 is used to improve the magnetic field distribution and reduce electromagnetic wave loss; moreover, the waveguide ridge 121 can improve mode matching and extend bandwidth. This disclosure does not limit the shape of the waveguide ridge 121 or its position within the waveguide back cavity 12.

[0076] In some embodiments, one or more ridge structures 111 are arranged in sequence in the waveguide transmission cavity 11.

[0077] The operating mode of a rectangular waveguide cavity is TE. 10 In the operating mode of the first microstrip differential line 41 and the second microstrip differential line 42, which is TEM mode, the impedance of the two modes is mismatched. To make the characteristic impedance of the waveguide equal to the characteristic impedance of the balanced antenna 31, a ridge structure 111 is provided in the rectangular waveguide cavity 11. The height and length of the ridge structure 111 can be set as needed. For example, in this embodiment, the height (thickness) of the ridge structure 111 is set to one-quarter of the waveguide wavelength, that is, the height of the ridge structure 111 is λ / 4, where λ is the waveguide wavelength, to achieve impedance matching between the two modes. In some embodiments, the height of the ridge can also be corrected by using the ripple frequency response characteristic method and compensation for the stepped capacitance effect of each ridge structure 111.

[0078] In this embodiment, the substrate 2 is disposed between the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the waveguide transmission cavity 11, the substrate 2 and the waveguide back cavity 12 are stacked in sequence.

[0079] In some embodiments, the substrate 2 includes at least a first substrate 21, and the waveguide transmission cavity 11 and the first substrate 21 can confine the electromagnetic wave to the vicinity of the conversion module 3 as much as possible, thereby improving the coupling efficiency of the waveguide.

[0080] In this embodiment, the conversion module 3 is disposed on the first substrate 21, that is, the first substrate 21 carries the conversion module 3, and the mode conversion of the waveguide microstrip differential line is realized through the conversion module 3.

[0081] In some embodiments, the conversion module 3 includes a balanced antenna 31, a first differential stripline 32, and a second differential stripline 33. The balanced antenna 31 is disposed in the region opposite to the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the region opposite to the feed port. The balanced antenna 31 is provided with a first output terminal 311 and a second output terminal 312 for outputting differential signals. One end of the first differential stripline 32 is connected to the first output terminal 311 of the balanced antenna 31, and the other end is connected to the first microstrip differential line 41, that is, the first output terminal 311 of the balanced antenna 31 is connected to the first microstrip differential line 41 through the first differential stripline 32; one end of the second differential stripline 33 is connected to the second output terminal 312 of the balanced antenna 31, and the other end is connected to the second microstrip differential line 42, that is, the second output terminal 312 of the balanced antenna 31 is connected to the second microstrip differential line 42 through the second differential stripline 33.

[0082] In some embodiments, the balanced antenna 31 includes a first antenna section 31a and a second antenna section 31b symmetrically arranged, the first antenna section 31a and the second antenna section 31b being connected by an antenna connection section 31c, a first output terminal 311 being disposed on the first antenna section 31a, and a second output terminal 312 being disposed on the second antenna section 31b.

[0083] In some embodiments, the first antenna portion 31a and the second antenna portion 31b are both right-angled triangles projected onto the first substrate 21, and the acute angle portion of the first antenna portion 31a and the acute angle portion of the second antenna portion 31b are connected by the antenna connection portion 31c.

[0084] In this embodiment, the balanced antenna 31 is a planar antenna, consisting of a symmetrically arranged first antenna section 31a and a second antenna section 31b connected together. To ensure tight coupling of the waveguide's fundamental mode, the direction in which the balanced antenna 31 is inserted into the waveguide cavity 1 can be adjusted according to the characteristics of the magnetic field distribution between the waveguide and the balanced antenna 31.

[0085] For example, when the waveguide cavity 1 is a rectangular waveguide cavity, the balanced antenna 31 is inserted into the waveguide cavity 1 from the narrow side of the rectangular waveguide cavity. This can make the electric field generated by the balanced antenna 31 consistent with the mode of the waveguide fundamental mode electric field, and can excite the fundamental mode of the waveguide.

[0086] In this embodiment of the disclosure, the waveguide is connected to the first differential stripline 32 and the second differential stripline 33 through the balanced antenna 31, and mode matching between the balanced antenna 31 and the first microstrip differential line 41 and the second microstrip differential line 42 is achieved.

[0087] In some embodiments, the conversion module 3 further includes a balancing stub 35, which is connected to the antenna connection portion 31c and located between the first differential stripline 32 and the second differential stripline 33.

[0088] The balancing stub 35 overlaps with the ground plane 34, meaning that part of the balancing stub 35 is located between the opposing regions of the waveguide transmission cavity 11 and the waveguide back cavity 12, while another part is located outside these opposing regions. According to the odd-even mode theory, when excited by a differential mode signal, the symmetry plane of the balanced antenna 31 can be equivalent to an electric wall, making the first antenna section 2a and the second antenna section 2b equivalent to a short-circuit ground. When excited by a common-mode signal, the symmetry plane of the balanced antenna 31 can be equivalent to a magnetic wall, making the first antenna section 2a and the second antenna section 2b equivalent to a band gap, thus improving the suppression capability of the balanced antenna 31 for common-mode signals in the differential mode passband. This eliminates the need for an internal grounding structure in the balanced antenna 31, reducing manufacturing difficulty.

[0089] In some embodiments, the substrate 2 further includes a second substrate 22, which is stacked with the first substrate 21 and located near the waveguide back cavity 12. The conversion module 3 is disposed between the first substrate 21 and the second substrate 22, that is, the waveguide transmission cavity 11, the first substrate 21, the conversion module 3, the second substrate 22 and the waveguide back cavity 12 are stacked in sequence.

[0090] In this embodiment of the present disclosure, the conversion module 3 is disposed between the first substrate 21 and the second substrate 22. The first substrate 21 and the waveguide transmission cavity 11 can be used to constrain the transmission of electromagnetic waves to the balanced antenna 31, and the second substrate 22 and the waveguide back cavity 12 can reduce the loss of electromagnetic waves.

[0091] In some embodiments, the balanced antenna 31 includes a monopole antenna or a dipole antenna. Monopole and dipole antennas are flexible in design, have a wide range of applications, and can use various types of waveguides.

[0092] like Figure 6As shown, when the balanced antenna 31 is a monopole antenna, the waveguide conversion device 3 also includes a ground plane 34, which is grounded or connected to a virtual ground. The ground plane 34 is stacked on the surface of the second substrate 22 adjacent to the waveguide back cavity 12. The width of the ground plane 34 is the same as that of the first substrate 21 and the second substrate 22, and the length of the ground plane 34 is less than the length of the first substrate 21 and the second substrate 22. The ground plane 34 is disposed on the outside of the waveguide back cavity 12, that is, the ground plane 34 is not inserted between the waveguide transmission cavity 11 and the waveguide back cavity 12.

[0093] Figure 7 This is a schematic diagram of another waveguide conversion device provided in an embodiment of this disclosure. Figure 7 As shown, the waveguide conversion device includes a waveguide cavity 1, a substrate 2, and a conversion module 3.

[0094] The waveguide cavity 1 is used to constrain the transmission direction of electromagnetic waves. The waveguide cavity 1 includes a waveguide transmission cavity 11 and a waveguide back cavity 12 arranged opposite to each other, and the area opposite the waveguide transmission cavity 11 and the waveguide back cavity 12 is the feed port.

[0095] In some embodiments, the waveguide cavity 1 is an elliptical waveguide cavity, that is, the waveguide transmission cavity 11 and the waveguide back cavity 12 are elliptical structures. At the same frequency, the elliptical waveguide cavity is lighter in mass, which is beneficial for the miniaturization and weight reduction of the structure.

[0096] In some embodiments, the height of the waveguide back cavity 12 is one-quarter of the waveguide wavelength, that is, the height of the waveguide back cavity 12 is λ / 4, where λ is the wavelength of the waveguide. This can improve the coupling efficiency of the waveguide, thereby improving the transmission efficiency of the waveguide, and thus improving the resonant frequency and bandwidth.

[0097] It should be noted that, although Figure 7 In the waveguide conversion device shown, the waveguide transmission cavity 11 does not have a ridge structure, but this does not mean that the waveguide transmission cavity 11 of this structure cannot have a ridge structure. The waveguide back cavity 12 does not have a waveguide ridge, but this does not mean that the waveguide back cavity 12 of this structure cannot have a waveguide ridge.

[0098] In this embodiment, the substrate 2 is disposed between the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the waveguide transmission cavity 11, the substrate 2 and the waveguide back cavity 12 are stacked in sequence.

[0099] In some embodiments, the substrate 2 includes at least a first substrate 21, and the waveguide transmission cavity 11 and the first substrate 21 can confine the electromagnetic wave to the vicinity of the conversion module 3 as much as possible, thereby improving the coupling efficiency of the waveguide.

[0100] In this embodiment, the conversion module 3 is disposed on the first substrate 21, that is, the first substrate 21 carries the conversion module 3, and the mode conversion of the waveguide microstrip differential line is realized through the conversion module 3.

[0101] In some embodiments, the conversion module 3 includes a balanced antenna 31, a first differential stripline 32, and a second differential stripline 33. The balanced antenna 31 is disposed in the region opposite to the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the region opposite to the feed port. The balanced antenna 31 is provided with a first output terminal 311 and a second output terminal 312 for outputting differential signals. One end of the first differential stripline 32 is connected to the first output terminal 311 of the balanced antenna 31, and the other end is connected to the first microstrip differential line 41, that is, the first output terminal 311 of the balanced antenna 31 is connected to the first microstrip differential line 41 through the first differential stripline 32; one end of the second differential stripline 33 is connected to the second output terminal 312 of the balanced antenna 31, and the other end is connected to the second microstrip differential line 42, that is, the second output terminal 312 of the balanced antenna 31 is connected to the second microstrip differential line 42 through the second differential stripline 33.

[0102] In some embodiments, the balanced antenna 31 includes a first antenna section 31a and a second antenna section 31b symmetrically arranged, the first antenna section 31a and the second antenna section 31b being connected by an antenna connection section 31c, a first output terminal 311 being disposed on the first antenna section 31a, and a second output terminal 312 being disposed on the second antenna section 31b.

[0103] In some embodiments, the first antenna portion 31a and the second antenna portion 31b are both right-angled triangles projected onto the first substrate 21, and the acute angle portion of the first antenna portion 31a and the acute angle portion of the second antenna portion 31b are connected by the antenna connection portion 31c.

[0104] In this embodiment, the balanced antenna 31 is a planar antenna, consisting of a symmetrically arranged first antenna section 31a and a second antenna section 31b connected together. To ensure tight coupling of the waveguide's fundamental mode, the direction in which the balanced antenna 31 is inserted into the waveguide cavity 1 can be adjusted according to the characteristics of the magnetic field distribution between the waveguide and the balanced antenna 31.

[0105] For example, when the waveguide cavity 1 is a rectangular waveguide cavity, the balanced antenna 31 is inserted into the waveguide cavity 1 from the narrow side of the rectangular waveguide cavity. This can make the electric field generated by the balanced antenna 31 consistent with the mode of the waveguide fundamental mode electric field, and can excite the fundamental mode of the waveguide.

[0106] In this embodiment of the disclosure, the waveguide is connected to the first differential stripline 32 and the second differential stripline 33 through the balanced antenna 31, and mode matching between the balanced antenna 31 and the first microstrip differential line 41 and the second microstrip differential line 42 is achieved.

[0107] In some embodiments, the conversion module 3 further includes a balancing stub 35, which is connected to the antenna connection portion 31c and located between the first differential stripline 32 and the second differential stripline 33.

[0108] The balancing stub 35 overlaps with the ground plane 34, meaning that part of the balancing stub 35 is located between the opposing regions of the waveguide transmission cavity 11 and the waveguide back cavity 12, while another part is located outside these opposing regions. According to the odd-even mode theory, when excited by a differential mode signal, the symmetry plane of the balanced antenna 31 can be equivalent to an electric wall, making the first antenna section 2a and the second antenna section 2b equivalent to a short-circuit ground. When excited by a common-mode signal, the symmetry plane of the balanced antenna 31 can be equivalent to a magnetic wall, making the first antenna section 2a and the second antenna section 2b equivalent to a band gap, thus improving the suppression capability of the balanced antenna 31 for common-mode signals in the differential mode passband. This eliminates the need for an internal grounding structure in the balanced antenna 31, reducing manufacturing difficulty.

[0109] In some embodiments, the substrate 2 further includes a second substrate 22, which is stacked with the first substrate 21 and located near the waveguide back cavity 12. The conversion module 3 is disposed between the first substrate 21 and the second substrate 22, that is, the waveguide transmission cavity 11, the first substrate 21, the conversion module 3, the second substrate 22 and the waveguide back cavity 12 are stacked in sequence.

[0110] In this embodiment of the present disclosure, the conversion module 3 is disposed between the first substrate 21 and the second substrate 22. The first substrate 21 and the waveguide transmission cavity 11 can be used to constrain the transmission of electromagnetic waves to the balanced antenna 31, and the second substrate 22 and the waveguide back cavity 12 can reduce the loss of electromagnetic waves.

[0111] In some embodiments, the balanced antenna 31 is a monopole antenna or a half-wave dipole antenna. Monopole antennas and half-wave dipole antennas are flexible in design, have a wide range of applications, and can use various types of waveguides.

[0112] When the balanced antenna 31 is a monopole antenna, the waveguide conversion device 3 also includes a ground plane 34, which is connected to a virtual ground. The ground plane 34 is stacked on the surface of the second substrate 22 adjacent to the waveguide back cavity 12. The width of the ground plane 34 is less than or equal to the width of the first substrate 21 and the second substrate 22, and the length of the ground plane 34 is less than the length of the first substrate 21 and the second substrate 22. The ground plane 34 can be located outside the waveguide back cavity 12, or part of the ground plane 34 can be extended into the waveguide cavity 1, as long as it does not affect waveguide propagation.

[0113] It should be noted that, Figure 7 The waveguide conversion device shown can be constructed in any way except for the different shapes of the waveguide transmission cavity 11 and the waveguide back cavity 12. Figure 1 , Figures 4 to 6 Arbitrary structures are not discussed further here.

[0114] Figure 8 This is a schematic diagram of another waveguide conversion device provided in an embodiment of this disclosure. Figure 8 As shown, the waveguide conversion device includes a waveguide cavity 1, a substrate 2, and a conversion module 3.

[0115] The waveguide cavity 1 is used to constrain the transmission direction of electromagnetic waves. The waveguide cavity 1 includes a waveguide transmission cavity 11 and a waveguide back cavity 12 arranged opposite to each other, and the area opposite the waveguide transmission cavity 11 and the waveguide back cavity 12 is the feed port.

[0116] In some embodiments, the waveguide cavity 1 is a circular waveguide cavity, that is, the waveguide transmission cavity 11 and the waveguide back cavity 12 are circular structures. At the same frequency, the circular waveguide has lower loss, which is beneficial to improving the performance of the wireless communication system.

[0117] In some embodiments, the height of the waveguide back cavity 12 is one-quarter of the waveguide wavelength, that is, the height of the waveguide back cavity 12 is λ / 4, where λ is the wavelength of the waveguide. This can improve the coupling efficiency of the waveguide, thereby improving the transmission efficiency of the waveguide, and thus improving the resonant frequency and bandwidth.

[0118] It should be noted that, although Figure 8 In the waveguide conversion device shown, the waveguide transmission cavity 11 does not have a ridge structure, but this does not mean that the waveguide transmission cavity 11 of this structure cannot have a ridge structure. The waveguide back cavity 12 does not have a waveguide ridge, but this does not mean that the waveguide back cavity 12 of this structure cannot have a waveguide ridge.

[0119] In this embodiment, the substrate 2 is disposed between the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the waveguide transmission cavity 11, the substrate 2 and the waveguide back cavity 12 are stacked in sequence.

[0120] In some embodiments, the substrate 2 includes at least a first substrate 21, and the waveguide transmission cavity 11 and the first substrate 21 can confine the electromagnetic wave to the vicinity of the conversion module 3 as much as possible, thereby improving the coupling efficiency of the waveguide.

[0121] In this embodiment, the conversion module 3 is disposed on the first substrate 21, that is, the first substrate 21 carries the conversion module 3, and the mode conversion of the waveguide microstrip differential line is realized through the conversion module 3.

[0122] In some embodiments, the conversion module 3 includes a balanced antenna 31, a first differential stripline 32, and a second differential stripline 33. The balanced antenna 31 is disposed in the region opposite to the waveguide transmission cavity 11 and the waveguide back cavity 12, that is, the region opposite to the feed port. The balanced antenna 31 is provided with a first output terminal 311 and a second output terminal 312 for outputting differential signals. One end of the first differential stripline 32 is connected to the first output terminal 311 of the balanced antenna 31, and the other end is connected to the first microstrip differential line 41, that is, the first output terminal 311 of the balanced antenna 31 is connected to the first microstrip differential line 41 through the first differential stripline 32; one end of the second differential stripline 33 is connected to the second output terminal 312 of the balanced antenna 31, and the other end is connected to the second microstrip differential line 42, that is, the second output terminal 312 of the balanced antenna 31 is connected to the second microstrip differential line 42 through the second differential stripline 33.

[0123] In some embodiments, the balanced antenna 31 includes a first antenna section 31a and a second antenna section 31b symmetrically arranged, the first antenna section 31a and the second antenna section 31b being connected by an antenna connection section 31c, a first output terminal 311 being disposed on the first antenna section 31a, and a second output terminal 312 being disposed on the second antenna section 31b.

[0124] In some embodiments, the first antenna portion 31a and the second antenna portion 31b are both right-angled triangles projected onto the first substrate 21, and the acute angle portion of the first antenna portion 31a and the acute angle portion of the second antenna portion 31b are connected by the antenna connection portion 31c.

[0125] In this embodiment, the balanced antenna 31 is a planar antenna, consisting of a symmetrically arranged first antenna section 31a and a second antenna section 31b connected together. To ensure tight coupling of the waveguide's fundamental mode, the direction in which the balanced antenna 31 is inserted into the waveguide cavity 1 can be adjusted according to the characteristics of the magnetic field distribution between the waveguide and the balanced antenna 31.

[0126] For example, when the waveguide cavity 1 is a rectangular waveguide cavity, the balanced antenna 31 is inserted into the waveguide cavity 1 from the narrow side of the rectangular waveguide cavity. This can make the electric field generated by the balanced antenna 31 consistent with the mode of the waveguide fundamental mode electric field, and can excite the fundamental mode of the waveguide.

[0127] In this embodiment of the disclosure, the waveguide is connected to the first differential stripline 32 and the second differential stripline 33 through the balanced antenna 31, and mode matching between the balanced antenna 31 and the first microstrip differential line 41 and the second microstrip differential line 42 is achieved.

[0128] In some embodiments, the conversion module 3 further includes a balancing stub 35, which is connected to the antenna connection portion 31c and located between the first differential stripline 32 and the second differential stripline 33.

[0129] The balancing stub 35 overlaps with the ground plane 34, meaning that part of the balancing stub 35 is located between the opposing regions of the waveguide transmission cavity 11 and the waveguide back cavity 12, while another part is located outside these opposing regions. According to the odd-even mode theory, when excited by a differential mode signal, the symmetry plane of the balanced antenna 31 can be equivalent to an electric wall, making the first antenna section 2a and the second antenna section 2b equivalent to a short-circuit ground. When excited by a common-mode signal, the symmetry plane of the balanced antenna 31 can be equivalent to a magnetic wall, making the first antenna section 2a and the second antenna section 2b equivalent to a band gap, thus improving the suppression capability of the balanced antenna 31 for common-mode signals in the differential mode passband. This eliminates the need for an internal grounding structure in the balanced antenna 31, reducing manufacturing difficulty.

[0130] In some embodiments, the substrate 2 further includes a second substrate 22, which is stacked with the first substrate 21 and located near the waveguide back cavity 12. The conversion module 3 is disposed between the first substrate 21 and the second substrate 22, that is, the waveguide transmission cavity 11, the first substrate 21, the conversion module 3, the second substrate 22 and the waveguide back cavity 12 are stacked in sequence.

[0131] In this embodiment of the present disclosure, the conversion module 3 is disposed between the first substrate 21 and the second substrate 22. The first substrate 21 and the waveguide transmission cavity 11 can be used to constrain the transmission of electromagnetic waves to the balanced antenna 31, and the second substrate 22 and the waveguide back cavity 12 can reduce the loss of electromagnetic waves.

[0132] In some embodiments, the balanced antenna 31 is a monopole antenna or a half-wave dipole antenna.

[0133] When the balanced antenna 31 is a monopole antenna, the waveguide conversion device 3 also includes a ground plane 34, which is grounded or connected to a virtual ground. The ground plane 34 is stacked on the surface of the second substrate 22 adjacent to the waveguide back cavity 12. The width of the ground plane 34 is the same as that of the first substrate 21 and the second substrate 22, and the length of the ground plane 34 is less than that of the first substrate 21 and the second substrate 22. The ground plane 34 is disposed on the outside of the waveguide back cavity 12, that is, the ground plane 34 is not inserted between the waveguide transmission cavity 11 and the waveguide back cavity 12.

[0134] It should be noted that, Figure 8 Except for the circular shapes of the waveguide transmission cavity 11 and the waveguide back cavity 12, the waveguide conversion device shown can adopt other structures. Figure 1 , Figures 4 to 6 Arbitrary structures are not discussed further here.

[0135] In some embodiments, the waveguide cavity includes any one of a rectangular waveguide cavity, a circular waveguide cavity, an elliptical waveguide cavity, and a ridge waveguide cavity.

[0136] It should be noted that in the above embodiments, the waveguide conversion device is provided with only one conversion module, but this does not imply a limitation on the number of conversion modules. The waveguide conversion device of this disclosure embodiment can be provided with two or more conversion modules. Multiple conversion modules can be arranged at intervals, cross-arranged, or stacked.

[0137] Figure 9 This is a simulation diagram of the S-characteristic of the waveguide conversion device provided in the embodiments of this disclosure. The horizontal axis represents frequency in GHz; the vertical axis represents loss in dB. Figure 9 It can be seen that the return loss (S11) is relatively small in the frequency range of 17GHz to 19.3GHz; the insertion loss (S21) is between -15dB and -25dB.

[0138] This disclosure also provides a wireless communication system including a waveguide conversion device. The waveguide conversion device provided in this disclosure achieves impedance matching and mode matching, and achieves low loss over a wide frequency band.

[0139] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0140] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A waveguide conversion device, comprising: A waveguide cavity, comprising a waveguide transmission cavity and a waveguide back cavity disposed opposite to each other; A substrate is disposed between the waveguide transmission cavity and the waveguide back cavity; the substrate includes at least a first substrate. A conversion module is disposed on the first substrate. The conversion module includes a balanced antenna, a first differential stripline, and a second differential stripline. The balanced antenna is disposed in the region opposite to the waveguide transmission cavity and the waveguide back cavity. The balanced antenna has a first output terminal and a second output terminal. The first end of the first differential stripline is connected to the first output terminal of the balanced antenna, and the first end of the second differential stripline is connected to the second output terminal of the balanced antenna. The waveguide conversion device further includes a ground plane, which is stacked with the substrate and disposed outside the waveguide cavity; The balanced antenna includes a first antenna section and a second antenna section symmetrically arranged, the first antenna section and the second antenna section are connected by an antenna connection section, the first output terminal is disposed on the first antenna section, and the second output terminal is disposed on the second antenna section; The conversion module further includes a balancing stub, which is connected to the antenna connection portion and located between the first differential stripline and the second differential stripline. The balancing stub overlaps with the ground plane. A portion of the balancing stub is located in the region opposite to the waveguide transmission cavity and the waveguide back cavity, while another portion is located outside the region opposite to the waveguide transmission cavity and the waveguide back cavity.

2. The waveguide conversion device according to claim 1, wherein, The projections of the first antenna portion and the second antenna portion onto the first substrate are both right-angled triangles, and the acute angle portion of the first antenna portion and the acute angle portion of the second antenna portion are connected through the antenna connecting portion; Alternatively, the projections of the first antenna portion and the second antenna portion onto the first substrate are both isosceles or equilateral triangles, and the apex of the first antenna portion and the apex of the second antenna portion are connected by the antenna connection portion. Alternatively, the projections of the first antenna portion and the second antenna portion onto the first substrate are both rectangular, and the short side of the first antenna portion and the short side of the second antenna portion are connected through the antenna connection portion.

3. The waveguide conversion device according to claim 1 or 2, wherein, The substrate further includes a second substrate, which is stacked on top of the first substrate and located near the back cavity of the waveguide; the conversion module is disposed between the first substrate and the second substrate.

4. The waveguide conversion device according to claim 3, wherein, The balanced antenna includes a monopole antenna or a dipole antenna.

5. The waveguide conversion device according to claim 3, wherein, The ground plane is disposed on the side of the second substrate near the waveguide back cavity, the ground plane is disposed on the side of the first substrate near the waveguide transmission cavity, or it is disposed between the first substrate and the second substrate.

6. The waveguide conversion device according to claim 1, wherein, The second end of the first differential stripline is connected to the first microstrip differential line, and the second end of the second differential stripline is connected to the second microstrip differential line.

7. The waveguide conversion device according to claim 1, wherein, A waveguide ridge is provided at the bottom of the waveguide back cavity.

8. The waveguide conversion device according to claim 1, wherein, The waveguide transmission cavity is provided with one or more ridge structures stacked sequentially.

9. The waveguide conversion device according to claim 1, wherein, The waveguide cavity includes any one of a rectangular waveguide cavity, an elliptical waveguide cavity, and a ridge waveguide cavity.

10. A wireless communication system, wherein, It includes a waveguide conversion device, wherein the waveguide conversion device is the waveguide conversion device according to any one of claims 1-9.

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