Microstrip waveguide conversion device

Abstract

This disclosure relates to a microstrip waveguide conversion device, comprising: a rectangular waveguide, a substrate, and a microstrip line disposed on the top surface of the substrate. The substrate extends from the side of the rectangular waveguide into a waveguide cavity within the rectangular waveguide via an air cavity. The microstrip line includes a microstrip probe, an impedance transformation section, and a microstrip transmission line connected in sequence. The microstrip probe is located in the waveguide cavity, a portion of the impedance transformation section is located in the air cavity, and another portion is located in the waveguide cavity. The microstrip transmission line is located in the air cavity. The microstrip probe includes a probe body and multiple rectangular protrusions extending from the probe body. Under the action of the multiple rectangular protrusions, the microstrip line forms multiple grooves at the microstrip probe. This device covers a wide wavelength range, is small in size, has a simple structure, is easy to manufacture, and has low cost.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and in particular to a microstrip waveguide conversion device. Background Technology

[0002] A microstrip-waveguide converter is a device that converts electromagnetic wave signals from a microstrip line to a waveguide. Microstrip lines and waveguides are two common media for transmitting electromagnetic waves, with different transmission characteristics and applications. Microstrip lines are typically used for signal transmission in integrated circuits, while waveguides are commonly used for signal transmission in microwave and millimeter-wave bands. Therefore, in some applications, it is necessary to transmit signals from a microstrip line to a waveguide, or vice versa. The microstrip-waveguide converter is the key component for achieving this conversion; it can convert electromagnetic wave signals from a microstrip line to signals in a waveguide, or vice versa. This device has wide applications in microwave and millimeter-wave communication systems, radar systems, measurement systems, and other fields.

[0003] Millimeter-wave radar, due to its higher frequency, offers advantages over centimeter-wave radar, including smaller size, lighter weight, and higher spatial resolution. Furthermore, compared to optical radar, millimeter-wave radar boasts stronger penetration capabilities, greater anti-interference capabilities, and the ability to handle complex weather and environmental conditions. Consequently, millimeter-wave radar has seen significant development in recent years.

[0004] As frequencies increase, traditional coaxial cables are gradually being replaced by metallic waveguides due to their large size, high transmission loss, and high cost. Metallic waveguides are widely used in millimeter-wave circuit systems due to their high power capacity and low loss. However, millimeter-wave circuit signal transmission primarily occurs through planar transmission lines, making the design of a transition structure from a planar transmission line to a waveguide crucial. The performance of the microstrip waveguide transition structure significantly impacts the performance of millimeter-wave radar systems.

[0005] Microstrip waveguide transition structures mainly include two types: microstrip probe transition structures and fin wire transition structures. Among them, the microstrip probe-to-waveguide transition structure is widely used in millimeter-wave systems. However, microstrip waveguide transition devices in related technologies suffer from problems such as complex structure, high manufacturing difficulty, small coverage band range, and high cost. Summary of the Invention

[0006] In view of this, the present disclosure proposes a microstrip waveguide conversion device.

[0007] According to one aspect of this disclosure, a microstrip waveguide conversion device is provided, the device comprising: a rectangular waveguide, a substrate, and a microstrip line disposed on the top surface of the substrate.

[0008] The substrate extends from the side of the rectangular waveguide into the waveguide cavity within the rectangular waveguide through an air cavity;

[0009] The microstrip line includes a microstrip probe, an impedance transformation section, and a microstrip transmission line connected in sequence. The microstrip probe is located in the waveguide cavity, a portion of the impedance transformation section is located in the air cavity, and another portion is located in the waveguide cavity. The microstrip transmission line is located in the air cavity.

[0010] The microstrip probe includes a probe body and a plurality of rectangular protrusions extending from the probe body. The microstrip line forms a plurality of grooves at the microstrip probe under the action of the plurality of rectangular protrusions.

[0011] The electromagnetic field signal is input from the input surface of the waveguide perpendicular to the side surface, and after conversion, it is output from the microstrip port of the microstrip line; or, the signal is input from the microstrip port of the microstrip line, and after conversion, it is output from the input surface of the waveguide perpendicular to the side surface.

[0012] In one possible implementation, the length of the waveguide cavity in the rectangular waveguide is 1 / 4 of the wavelength of the electromagnetic field signal, and the length of the waveguide cavity is the distance between the input surface and the short surface.

[0013] In one possible implementation, a metal layer is applied to a target area on the bottom surface of the substrate opposite to the top surface, the target area being the region of the bottom surface within the air cavity, and the material of the metal layer includes gold.

[0014] In one possible implementation, the substrate is further provided with a positioning mark, which is used to mark the length of the substrate extending into the waveguide cavity, so as to facilitate the assembly of the device.

[0015] In one possible implementation, the location identifier is also used to mark the boundary of the target area.

[0016] In one possible implementation, the length of the impedance transformation segment is 1 / 4 of the wavelength of the electromagnetic field signal.

[0017] In one possible implementation, the opening direction of each groove is parallel to the extension direction of the microstrip line.

[0018] The groove includes: a first groove with an opening direction in the same direction as the extension direction, formed based on two rectangular protrusions and the probe body; and two second grooves with opening directions opposite to the first groove, each of the second grooves being formed based on one of the rectangular protrusions, the impedance transformation section, and the probe body.

[0019] In one possible implementation, the substrate is made of quartz and has a thickness of 50 μm-100 μm.

[0020] In one possible implementation, the edges on the short surface of the rectangular waveguide are rounded.

[0021] In one possible implementation, the waveguide cavity is connected to the air cavity.

[0022] The microstrip waveguide conversion device provided in this disclosure, based on a traditional E-plane microstrip probe, expands the bandwidth by changing the shape of the microstrip probe to form multiple resonant points. Furthermore, the device effectively covers the E-band, W-band, and most of the F-band, with an average transition loss of less than 0.25 dB. Therefore, in some ultra-wideband operating scenarios, it can reduce the number of transmission links and the use of modular components, thereby reducing system complexity, weight, size, and cost, and improving system stability and reliability. This has significant implications in the fields of instrumentation, communication, radar, and spaceborne satellites. Moreover, the device is small in size, simple in structure, and easy to manufacture, which reduces costs.

[0023] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0025] Figure 1 , Figure 2 A three-dimensional structural schematic diagram of a microstrip waveguide conversion device according to an embodiment of the present disclosure is shown.

[0026] Figure 3 A top view of a microstrip waveguide conversion device according to an embodiment of the present disclosure is shown.

[0027] Figure 4 A side view of a microstrip waveguide conversion device according to an embodiment of the present disclosure is shown.

[0028] Figure 5 A top view of the top surface of a substrate in a microstrip waveguide conversion device according to an embodiment of the present disclosure is shown.

[0029] Figure 6 A top view of the bottom surface of a substrate in a microstrip waveguide conversion device according to an embodiment of the present disclosure is shown.

[0030] Figure 7 A schematic diagram of the microstrip line structure in a microstrip waveguide conversion device according to an embodiment of the present disclosure is shown.

[0031] Figure 8 A schematic diagram showing simulation results of a microstrip waveguide conversion device according to an embodiment of the present disclosure is provided. Detailed Implementation

[0032] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0033] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0034] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0035] To address the aforementioned technical problems, this disclosure provides a microstrip waveguide conversion device. Based on a traditional E-plane microstrip probe, this device expands the bandwidth by changing the shape of the microstrip probe to form multiple resonant points. Furthermore, the device effectively covers the E-band, W-band, and most of the F-band, with an average transition loss of less than 0.25 dB. Therefore, in some ultra-wideband operating scenarios, it can reduce the number of transmission links and the use of modular components, thereby reducing system complexity, weight, size, and cost, and improving system stability and reliability. This has significant implications in the fields of instrumentation, communication, radar, and spaceborne satellites. Moreover, the device is small in size, simple in structure, and easy to manufacture, thus reducing costs.

[0036] like Figures 1-7 As shown, the microstrip waveguide conversion device includes: a rectangular waveguide 1, a substrate 2, and a microstrip line 3 disposed on the top surface (i.e., the top surface) of the substrate 2.

[0037] The substrate 2 extends from the side of the rectangular waveguide 1 into the waveguide cavity 11 inside the rectangular waveguide 1 through the air cavity 4.

[0038] The microstrip line 3 includes a microstrip probe 31, an impedance transformation section 32, and a microstrip transmission line 33 connected in sequence. The microstrip probe 31 is located in the waveguide cavity 11. To further extend the bandwidth, a part of the impedance transformation section 32 is located in the air cavity 4, and another part is located in the waveguide cavity 11. The microstrip transmission line 33 is located in the air cavity 4.

[0039] The microstrip probe 31 includes a probe body 311 and a plurality of rectangular protrusions 312 extending from the probe body 311. The microstrip line 3 forms a plurality of grooves 34 at the microstrip probe 31 under the action of the plurality of rectangular protrusions 312.

[0040] The electromagnetic field signal is input from the input surface 12 of the waveguide 1, which is perpendicular to the side surface, and output from the microstrip port 5 of the microstrip line 3 after conversion; or, the signal is input from the microstrip port 5 of the microstrip line 3, and output from the input surface 12 of the waveguide 1, which is perpendicular to the side surface.

[0041] In this embodiment, taking the example of an electromagnetic field signal being input from the input surface 12 perpendicular to the side of the waveguide 1 and output from the microstrip port 5 of the microstrip line 3 after conversion, the signal conversion process is illustrated as follows: After the electromagnetic field signal is input from the input surface 12 perpendicular to the side of the waveguide 1, a portion of the electromagnetic field signal is coupled to the microstrip probe 31; the remaining portion of the electromagnetic wave signal reaches the short surface 13 parallel to the input surface 12 of the waveguide 1 and is transmitted to the microstrip probe 31 after total reflection at the short surface 12. The two portions of the electromagnetic wave signal are superimposed in phase at the microstrip probe 31, and after frequency and / or phase adjustment through multiple grooves 34 and multiple resonant points formed by the microstrip probe 31 and the sidewall of the waveguide 11, they enter the impedance transformation section 32 and are transmitted to the microstrip transmission line 33, and then output from the microstrip port 5 of the microstrip line 3. Thus, the conversion from waveguide 1TE10 mode to microstrip line 3 quasi-TEM mode was completed within a relatively wide frequency band.

[0042] In this embodiment, the length of the waveguide cavity 11 in the rectangular waveguide 1 is 1 / 4 of the wavelength of the electromagnetic field signal, and the length of the waveguide cavity 11 is the distance between the input surface 12 and the short surface 13.

[0043] In this embodiment, a metal layer 7 is applied to the target area of ​​the bottom surface (i.e., the bottom surface) of the substrate 2 opposite to the top surface. The target area is the region of the bottom surface within the air cavity 4, and the material of the metal layer 7 may include gold. This gold-backed bottom surface improves the overall consistency of the device. Furthermore, since the portion of the substrate 2 outside the target area needs to extend into the waveguide cavity 11, the substrate 2 is inserted into the waveguide cavity 11 based on the boundary of the gold-backed target area during assembly. This allows for more accurate insertion depth of the substrate 2 into the waveguide cavity 11, improving assembly precision.

[0044] In this embodiment, a positioning mark 6 may also be provided on the substrate 2. The positioning mark 6 is used to mark the length of the substrate 2 extending into the waveguide cavity 11, facilitating the assembly of the device. In some embodiments, the positioning mark 6 may also be used to mark the boundary of the target area. The positioning mark 6 may be located on the top surface of the substrate 2. This allows for the initial formation of the microstrip line 3 and the positioning mark 6 on the top surface of the substrate 2 during processing. Then, based on the positioning mark 6, the target area requiring back gold coating on the bottom surface of the substrate 2 can be directly determined, simplifying the fabrication of the metal layer on the bottom surface of the substrate 2. Furthermore, the positioning mark 6 can also optimize and adjust the performance of the entire device, improving its overall performance.

[0045] In some embodiments, the positioning identifier 6 may be a rectangle, square, or other shape, and its size may be set according to actual needs; this disclosure does not limit this. The positioning identifier 6 may include one or more. For example, such as... Figure 2 , Figure 5 , Figure 6 As shown, the positioning mark 6 includes two square, 20μm*20μm metal marks, which are located on opposite sides of the substrate 2.

[0046] It is understandable that the implementation method of the positioning mark 6 can be set according to actual needs without affecting the normal function of the device, and this disclosure does not impose any restrictions on this.

[0047] In this embodiment, the material of the substrate 2 may include quartz. The size and shape of the substrate 2 can be set according to the material of the substrate 2, the size of the microstrip line 3, etc., and this disclosure does not limit this. The thickness of the substrate 2 can be 50μm-100μm. In some embodiments, the thickness of the substrate 2 can be 50μm or 80μm.

[0048] In this embodiment, as Figure 7 As shown, the length L1 of the impedance transformation section 32 can be 1 / 4 of the wavelength of the electromagnetic field signal. The length L2 of the microstrip transmission line 33 can be 500μm-1000μm, such as 600μm or 800μm. The width W1 of the impedance transformation section 32 can be 40μm-80μm, such as 50μm or 70μm, and the width W2 of the microstrip transmission line 33 is 104μm. There is a certain proportional relationship between the width W1 of the impedance transformation section 32 and the width W2 of the microstrip transmission line 33, and W1 / W2 can be between 0.4 and 0.8, such as 0.5 or 0.7.

[0049] In this embodiment, the number, position, and size of the grooves 34 can be set according to actual needs to meet different signal conversion requirements. In some embodiments, such as Figure 5 , Figure 7 As shown, the opening direction of each of the grooves 34 is parallel to the extension direction of the microstrip line 3 (i.e., the length direction of the microstrip line 3). The groove 34 may include: a first groove 341 with an opening direction in the same direction as the extension direction, formed based on two rectangular protrusions 312 and the probe body 311; and two second grooves 342 with opening directions opposite to the first groove 341, each second groove 342 being formed based on one of the rectangular protrusions 312, the impedance transformation section 32, and the probe body 311. In some embodiments, such as... Figure 7 As shown, the depth h1 of the first groove 341 is 90 μm and the width is 170 μm. The depth h2 of the second groove 342 is 90 μm and the width is 50 μm.

[0050] In this embodiment, the edges of the short-circuit surface 13 of the rectangular waveguide 1 are rounded. Rounding the corners of the rectangular waveguide 1 achieves good impedance matching and facilitates fabrication. High sealing performance completely confines electromagnetic energy within the waveguide cavity 11, reducing interference to external circuits and improving overall electromagnetic compatibility.

[0051] In this embodiment, the waveguide cavity 11 is connected to the air cavity 4.

[0052] This disclosure also includes simulation tests on the microstrip waveguide conversion device provided in this disclosure, and the test results are as follows: Figure 8 As shown, S11 return loss represents the loss due to the partial reflection of the input signal, and S12 insertion loss represents the loss due to the load power of the device itself. Combined with... Figure 8 The simulation results show that the microstrip waveguide converter has a return loss of less than -10dB and an insertion loss of less than -1dB in the 65GHz to 130GHz frequency band, indicating good performance.

[0053] It should be noted that although the above embodiments have been used as examples to illustrate the microstrip waveguide conversion device, those skilled in the art will understand that this disclosure is not limited thereto. In fact, users can flexibly configure each part according to their personal preferences and / or actual application scenarios, as long as it conforms to the technical solution of this disclosure.

[0054] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A microstrip waveguide conversion device, characterized in that, The device includes: a rectangular waveguide (1), a substrate (2), and a microstrip line (3) disposed on the top surface of the substrate (2). The substrate (2) extends from the side of the rectangular waveguide (1) into the waveguide cavity (11) inside the rectangular waveguide (1) through the air cavity (4); The microstrip line (3) includes a microstrip probe (31), an impedance transformation section (32), and a microstrip transmission line (33) connected in sequence. The microstrip probe (31) is located in the waveguide cavity (11). A part of the impedance transformation section (32) is located in the air cavity (4), and another part is located in the waveguide cavity (11). The microstrip transmission line (33) is located in the air cavity (4). The microstrip probe (31) includes a probe body (311) and a plurality of rectangular protrusions (312) extending from the probe body (311). The microstrip line (3) forms a plurality of grooves (34) at the microstrip probe (31) under the action of the plurality of rectangular protrusions (312). The electromagnetic field signal is input from the input surface (12) of the waveguide (1) perpendicular to the side surface, and output from the microstrip port (5) of the microstrip line (3) after conversion; or, the signal is input from the microstrip port (5) of the microstrip line (3), and output from the input surface (12) of the waveguide (1) perpendicular to the side surface after conversion.

2. The apparatus according to claim 1, characterized in that, The length of the waveguide cavity (11) in the rectangular waveguide (1) is 1 / 4 of the wavelength of the electromagnetic field signal, and the length of the waveguide cavity (11) is the distance between the input surface (12) and the short surface (13) parallel to the input surface (12).

3. The apparatus according to claim 1, characterized in that, A metal layer (7) is covered on a target area of ​​the bottom surface of the substrate (2) opposite to the top surface. The target area is the area of ​​the bottom surface within the air cavity (4). The material of the metal layer (7) includes gold.

4. The apparatus according to claim 3, characterized in that, The substrate (2) is also provided with a positioning mark (6), which is used to mark the length of the substrate (2) extending into the waveguide cavity (11) to facilitate the assembly of the device.

5. The apparatus according to claim 4, characterized in that, The location identifier (6) is also used to mark the boundary of the target area.

6. The apparatus according to claim 1, characterized in that, The length of the impedance transformation segment (32) is 1 / 4 of the wavelength of the electromagnetic field signal.

7. The apparatus according to claim 1, characterized in that, The opening direction of each groove (34) is parallel to the extension direction of the microstrip line (3). The groove (34) includes: a first groove (341) with the opening direction being the same as the extension direction, formed based on two rectangular protrusions (312) and the probe body (311); and two second grooves (342) with the opening direction being opposite to the first groove (341). Each second groove (342) is formed based on one of the rectangular protrusions (312), the impedance transformation segment (32), and the probe body (311).

8. The apparatus according to claim 1, characterized in that, The substrate (2) is made of quartz and has a thickness of 50 μm-100 μm.

9. The apparatus according to claim 2, characterized in that, The edges of the short surface (13) of the rectangular waveguide (1) are rounded.

10. The apparatus according to claim 1, characterized in that, The waveguide cavity (11) is connected to the air cavity (4).

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