A chip-to-waveguide switching device

Abstract

A chip-to-waveguide transition device provided by the present invention directly connects the pins of a chip body to a metal layer in a substrate structure, and then introduces signals into a waveguide through a signal transmission channel. Compared with connecting chip pins to a microstrip line and then introducing signals into the waveguide through a microstrip line transition interface, the chip-to-waveguide transition device provided by the present invention removes the microstrip line and the transition structure (such as a high-frequency substrate integrating a microstrip line), reduces the system complexity, and thus reduces unnecessary radiation interference. At the same time, the link loss is reduced. In addition, since signals do not need to be introduced into the waveguide through a semi-open microstrip line, the cross-coupling between channels is also reduced.

Description

Technical Field

[0001] The present invention relates to the field of vehicle-mounted millimeter-wave radar and unmanned driving, and in particular to a chip-to-waveguide switching device. Background Art

[0002] With the development of unmanned driving, high-performance millimeter-wave radars are also urgently needed. Long detection distance, high precision, multi-point cloud, low cost, 4D (distance, speed, angle, height) detection, etc. have also become the goals pursued by modern millimeter-wave radars. This puts higher requirements on millimeter-wave radar antennas. Millimeter-wave radars require more channels and antennas. With the increase in the number of antennas and the increase in the aperture, traditional microstrip antennas are no longer advantageous. Because the large aperture will increase the area of ​​expensive high-frequency plates, this is bound to increase costs. And too many microstrip antennas will increase the complexity of the microstrip interconnection structure and the length of the microstrip line. This not only increases the loss of the interconnection structure between the microstrip antenna and the chip pins of the transceiver chip, but the complex interconnection structure will also increase the radiation interference of the feeder and the mutual coupling between the feeders, greatly reducing the performance of the antenna.

[0003] Based on the above, 3D waveguide antennas are increasingly used in millimeter-wave radars. The interconnection between 3D waveguide antennas and chip pins has become one of its core technologies. The conversion structure from the chip pins of existing transceiver chips to waveguide antennas is that the chip pins lead out microstrip lines, and then the microstrip lines are transferred to the waveguide tube of the 3D waveguide antenna through a transfer structure. This technology requires a high-frequency substrate with integrated microstrip lines. A high-frequency substrate with integrated microstrip lines will increase the complexity of the system, causing excessive radiation interference and mutual coupling between channels. The microstrip lines will also bring channel insertion loss, affecting the signal transmission quality. Summary of the invention

[0004] The present invention provides a chip-to-waveguide switching device for solving the technical problems of waveguide antennas.

[0005] The present invention provides a chip-to-waveguide switching device, comprising:

[0006] Transceiver chip;

[0007] A waveguide, located on one side of the transceiver chip;

[0008] A substrate structure is located between the transceiver chip and the waveguide tube; the substrate structure includes at least two metal layers arranged opposite to each other, and a dielectric substrate located between the at least two metal layers, wherein the metal layer facing the transceiver chip is connected to the pin of the transceiver chip, and the metal layer facing the waveguide tube is connected to the waveguide tube;

[0009] A signal transmission channel penetrating all the metal layers and the dielectric substrate is formed on the substrate structure, and a waveguide cavity corresponding to the position of the signal transmission channel is formed on the waveguide.

[0010] In a feasible implementation manner, one of at least two of the metal layers includes a first dielectric layer disposed close to the transceiver chip, the first dielectric layer is connected to the pin, and the surface of the first dielectric layer is copper-coated;

[0011] The signal transmission channel includes a first signal transmission port formed on the first dielectric layer.

[0012] In a feasible implementation manner, the other of at least two of the metal layers includes a second dielectric layer disposed close to the waveguide, the second dielectric layer is connected to the waveguide, and the surface of the second dielectric layer is copper-coated;

[0013] The signal transmission channel includes a second signal transmission port formed on the second dielectric layer, and the first signal transmission port and the second signal transmission port together form both ends of the signal transmission channel.

[0014] In a feasible implementation manner, the second dielectric layer is arranged parallel to the first dielectric layer, and the first signal transmission port is located at the center of the first dielectric layer, and the second signal transmission port is located at the center of the second dielectric layer.

[0015] In a feasible implementation manner, the signal transmission channel includes a metal signal transmission hole formed on the dielectric substrate, and both ends of the metal signal transmission hole are disposed opposite to the first signal transmission port and the second signal transmission port respectively.

[0016] In a feasible implementation manner, a copper sheet interface is provided in the middle of the first dielectric layer, the copper sheet interface is connected to the pin, and the first signal transmission port is opened in the middle of the copper sheet interface; the aperture of the metal signal transmission hole is the same as that of the first signal transmission port and they are concentrically arranged;

[0017] The second dielectric layer is provided with a metal connecting piece, the metal connecting piece is connected to the waveguide, the second signal transmission port is opened in the middle of the metal connecting piece, and the second signal transmission port is concentrically arranged with the metal signal transmission hole and the first signal transmission port and has the same aperture.

[0018] In a feasible implementation manner, the second dielectric layer is of a hollow shape, the metal connecting piece is of a convex stepped shape or a square stepped shape, and the metal connecting piece extends from the inner side wall of one side of the second dielectric layer towards the inner center.

[0019] In a feasible implementation, a metallized via array penetrating all the metal layers and the dielectric substrate is further provided on the substrate structure. The shape of the metallized via array matches the shape of the waveguide cavity and is distributed along the outside of the waveguide cavity.

[0020] In a feasible implementation, the waveguide is a rectangular waveguide, the waveguide cavity is a rectangular through-hole, the metallized via array is distributed along a rectangle on the substrate structure, and a rectangular opening matching the shape of the waveguide cavity is formed in the middle of the second dielectric layer.

[0021] In a feasible implementation, the waveguide is an annular waveguide, the waveguide cavity is a circular through-hole, the metallized via array is distributed along a ring on the substrate structure, and an annular opening matching the shape of the waveguide cavity is formed in the middle of the second dielectric layer.

[0022] In a feasible implementation, a first connection layer is further provided between the substrate structure and the waveguide, and a second connection layer is further provided between the substrate structure and the chip body. The first connection layer and the second connection layer are welded or glued.

[0023] A chip-to-waveguide transition device provided by the present invention directly connects the pins of the chip body to the metal layers in the substrate structure, and then introduces signals into the waveguide through the signal transmission channel. Compared with connecting the chip pins to the microstrip line and then introducing the signals into the waveguide through the microstrip transition interface, the chip-to-waveguide transition device provided by the present invention removes the microstrip line and its microstrip transition structure (such as a high-frequency substrate integrated with a microstrip line), reduces the system complexity, thereby reducing unnecessary radiation interference, and also reducing the link loss. In addition, since the signal does not need to be introduced into the waveguide through the semi-open microstrip line, the mutual coupling between channels is also reduced. Description of the Drawings

[0024] Figure 1 is a schematic diagram of the overall structure of a chip-to-waveguide transition device provided by an embodiment of the present application;

[0025] Figure 2 is Figure 1 a planar schematic diagram of the first dielectric layer in

[0026] Figure 3 is Figure 1 a planar schematic diagram of the second dielectric layer in

[0027] Figure 4 is Figure 1 a planar schematic diagram of the waveguide in

[0028] Figure 5A characteristic curve diagram of signal reflection coefficient and transmission coefficient measured in actual application for a chip-to-waveguide switching device provided in an embodiment of the present application;

[0029] Figure 6 A schematic diagram of the overall structure of a chip-to-waveguide transition device of a ring waveguide in a chip-to-waveguide transition device provided in an embodiment of the present application.

[0030] Description of reference numerals:

[0031] 100, transceiver chip; 200, substrate structure; 300, waveguide; 400, connection layer;

[0032] 101, chip body; 102, pin;

[0033] 201, first dielectric layer; 202, dielectric substrate; 203, second dielectric layer; 204, signal transmission channel; 205, metallized through hole array;

[0034] 201a, first signal transmission port; 201b, copper sheet interface;

[0035] 202a, metal signal transmission hole;

[0036] 203a, second signal transmission port; 203b, metal connecting piece; 203c, rectangular opening; 203d, annular opening;

[0037] 301. Waveguide cavity. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present invention.

[0039] Since the conversion structure from the existing chip pin to the waveguide antenna is that the chip pin leads to a microstrip line, and then the microstrip line is transferred to the waveguide of the 3D waveguide antenna through a transfer structure. This technology requires a high-frequency substrate, which not only increases the cost, but the introduction of the microstrip line also increases the radiation interference and mutual coupling between channels, and the microstrip line will also bring insertion loss to the channel. Therefore, a transfer structure from chip pin to waveguide is proposed, which allows the chip pin to directly introduce the signal into the waveguide through the substrate and the metallized signal transmission through hole, without the need to lead out the microstrip line and high-frequency substrate. It can not only greatly reduce the cost, but also reduce the insertion loss and mutual coupling, and also reduce the complexity of the system, which has strong practicality in the field of millimeter wave radar.

[0040] Figure 1 It is a schematic diagram of the overall structure of the chip-to-waveguide switching device; Figure 2 is a schematic plan view of the first dielectric layer 201; Figure 3 is a schematic plan view of the second dielectric layer 203; Figure 4 is a plan view of the waveguide 300; Figures 1 to 4 The present invention provides a chip-to-waveguide switching device, which includes a transceiver chip 100, a substrate structure 200 and a waveguide 300. The transceiver chip 100 is used to send or receive signals, and includes a chip body 101 and a plurality of pins 102. The pins 102 are distributed on one side of the chip body 101. The pins 102 are used to transmit signals from the chip body 101 to the outside, or to receive signals from the outside.

[0041] The waveguide tube 300 is a part of the entire waveguide structure and is used as a signal transceiver port. It is arranged at one end of the substrate structure 200 away from the transceiver chip 100 and connected to the metal layer. A waveguide cavity 301 corresponding to the position of the signal transmission channel 204 is opened in the middle of the waveguide tube 300.

[0042] The substrate structure 200 is used to connect the transceiver chip 100 and the waveguide tube 300, and transmit signals between the transceiver chip 100 and the waveguide tube 300. One end of the substrate structure 200 is connected to the pin 102 of the transceiver chip 100, and includes two parallel metal layers and a dielectric substrate 202 located between the metal layers; a signal transmission channel 204 is formed on the substrate structure 200, and the signal transmission channel 204 runs through both ends of the substrate structure 200, and is used to transmit signals transmitted from the pin 102 or transmit signals received from the outside to the pin 102.

[0043] The substrate structure 200 replaces the prior art of connecting the waveguide 300 with a microstrip line extending from the chip pin 102 or connecting the waveguide 300 with a high-frequency substrate integrated with a microstrip line, which can effectively reduce the signal interference loss caused by the microstrip line and the high-frequency substrate.

[0044] The present invention provides a chip-to-waveguide switching device, which directly connects the pin 102 of the chip body 101 with the metal layer in the substrate structure 200, and then introduces the signal into the waveguide tube 300 through the metallized through hole. Compared with the chip pin 102 connecting the microstrip line and then introducing the signal into the waveguide through the microstrip line switching interface, the chip-to-waveguide switching device provided by the present invention removes the microstrip line and its microstrip switching structure (such as a high-frequency substrate with integrated microstrip line), reduces the system complexity, thereby reducing unnecessary radiation interference. At the same time, the link loss is reduced. In addition, the signal does not need to be introduced into the waveguide tube 300 through a semi-open microstrip line, which also reduces the mutual coupling between channels.

[0045] likeFigure 1 and Figure 2 As shown in Figure 2 , the metal layer in the substrate structure 200 includes a first dielectric layer 201 close to the transceiver chip 100 and connected to the pin 102. The surface of the first dielectric layer 201 is coated with copper. A first signal transmission port 201a is formed in the middle of the first dielectric layer 201, and the first signal transmission port 201a is located at one end of the signal transmission channel 204.

[0046] The first dielectric layer 201 with copper coating is equivalent to a ground wire, which can effectively reduce signal transmission loss and provide space and a base for the connection of the pin 102. The middle first signal transmission port 201a provides a port for directly connecting the signal transceiver to the pin 102.

[0047] As Figure 2 shown in Figure 2 , the first dielectric layer 201 in this embodiment is rectangular. The first signal transmission port 201a is located in the middle of the first dielectric layer 201, and the copper coating on the surface of the first dielectric layer 201 has good electrical properties.

[0048] Figure 2 A copper sheet interface 201b is provided in the middle of the first dielectric layer 201 in Figure 2 . The copper sheet interface 201b is connected to the pin 102, and the first signal transmission port 201a is opened in the middle of the copper sheet interface 201b. A round hole is opened in the middle of the first dielectric layer 201 in this embodiment, and the copper sheet interface 201b is circularly arranged in the first dielectric layer 201. Other shapes such as polygons can also be selected.

[0049] As Figure 1 and Figure 3 shown in Figure 3 , the metal layer further includes a second dielectric layer 203 away from the transceiver chip 100 and arranged parallel to the first dielectric layer 201. A second signal transmission port 203a is provided in the middle of the second dielectric layer 203. The first signal transmission port 201a and the second signal transmission port 203a together form both ends of the signal transmission channel 204. The surface of the second dielectric layer 203 also uses copper coating material and has good electrical properties. The second dielectric layer 203 can also be regarded as a ground wire for reducing interference in signal transmission.

[0050] As Figure 1As shown, a metal signal transmission hole 202a is provided on the dielectric substrate 202 located between the first dielectric layer 201 and the second dielectric layer 203, and is directly opposite to the first signal transmission port 201a and the second signal transmission port 203a. The metal signal transmission hole 202a runs through both ends of the dielectric substrate 202, and together with the first signal transmission port 201a and the second signal transmission port 203a, forms the signal transmission channel 204. The dielectric substrate 202 can be made of RF4 material, with a relative dielectric constant of 4.3, a loss tangent of 0.025, and a substrate thickness of 0.4 mm. The dielectric itself is basically non-conductive.

[0051] The signal transmission channel 204 is similar to the coaxial line in the antenna, which is used as a feeder for signal transmission. The signal transmission channel 204 is integrated in the substrate structure 200, which can be used as a carrier for waveguide transmission and as a connector between the chip and the waveguide 300 in structure, thereby improving the overall compactness of the switching structure, reducing the complexity of the system, and thus reducing unnecessary radiation interference. At the same time, the link loss is reduced. Since the signal does not need to be introduced into the waveguide 300 through a semi-open microstrip line, the mutual coupling between channels is also reduced.

[0052] Reference Figures 1 to 3 As shown, in this embodiment, the aperture of the metal signal transmission hole 202a is consistent with the first signal transmission port 201a and the two are concentrically arranged; the second dielectric layer 203 is provided with a metal connecting piece 203b, and the second signal transmission port 203a is opened in the middle of the metal connecting piece 203b. The second signal transmission port 203a is concentrically arranged with the metal signal transmission hole 202a and the first signal transmission port 201a and has the same aperture. Since the signal transmission channel 204 is equivalent to a coaxial line, the apertures of the first signal transmission port 201a, the second signal transmission port 203a and the metal signal transmission hole 202a are set to be the same to form a coaxial line structure.

[0053] like Figure 2 As shown, the diameter of the copper sheet interface 201b is 3.2 mm, and the diameter of the circular groove opened around the copper sheet interface 201b is 5.1 mm.

[0054] like Figure 3 As shown, a rectangular opening 203c is provided inside the second dielectric layer 203, and the metal connecting piece 203b is in a convex step shape, and the metal connecting piece 203b extends from the inner side wall of one side of the second dielectric layer 203 to the inner center, and the metal connecting piece 203b here can be equivalent to a waveguide ridge. The metal connecting piece 203b places the second signal transmission port 203a in the center facing the waveguide cavity 301.

[0055] like Figure 4As shown, the rectangular metal groove at the bottom of the second dielectric layer 203 is 2.6 mm long and 0.8 mm wide, and the step size of the metal groove sidewall is: the large rectangular structure is 1.7 mm long and 0.25 mm wide, and the small rectangular structure is 0.32 mm long and 0.31 mm wide.

[0056] As an alternative, the metal connecting piece 203b may also be configured to be in a directional step shape, and the position of the second signal transmission port 203a may correspond to the metal information transmission hole.

[0057] Since waveguide transmission requires a waveguide that matches the shape of the waveguide tube 300, a metallized through hole array 205 that matches the shape of the waveguide cavity 301 of the waveguide tube 300 is also provided on the substrate structure 200. The metallized through hole array 205 runs through both ends of the substrate structure 200, so that the metallized dielectric substrates 202 at both ends are electrically connected. The metallized through hole array 205 can limit the lateral diffusion of electromagnetic waves within its range, and the area enclosed by the metallized through hole array 205 together with the first metal dielectric substrate 202 and the second metal dielectric substrate 202 constitute an equivalent electromagnetic resonant cavity. In order to improve the resonance efficiency, the distance between adjacent metallized through holes does not exceed half the dielectric wavelength.

[0058] The rectangular structure surrounded by the metallized through hole array 205 on the first dielectric layer 201 is 2.8 mm long and 1 mm wide.

[0059] Specifically, Figure 4 As shown, the waveguide tube 300 in this embodiment is a rectangular waveguide with a length of 2.6 mm and a width of 0.8 mm. The waveguide cavity 301 is a rectangular through hole. The metallized through hole array 205 is distributed along a rectangle on the substrate structure 200. A rectangular opening 203c matching the shape of the waveguide cavity 301 is provided in the middle of the second dielectric layer 203.

[0060] Using the above size adapter, Figure 5 The reflection coefficient and transmission coefficient characteristic diagram of the signal, where the dotted line S1,1 represents the reflection coefficient, the solid line S2,1 represents the transmission coefficient, the x-axis represents the input signal frequency (unit: GHz), and the y-axis represents the signal reflection coefficient and transmission coefficient value of the antenna input port (unit: dB). Figure 5 It can be seen that at the millimeter wave frequency of 76-81GHz, the return loss is less than -15dB. The insertion loss has no obvious fluctuation, indicating that the signal transmission in the adapter is stable and a high equal amplitude conversion efficiency is achieved in the millimeter wave frequency band.

[0061] In this embodiment, the dimensions of each component in the substrate structure and the arrangement of the metallized through-hole array are controlled by computer software with the goal of achieving the best return loss and access loss of the switching device in the millimeter wave antenna waveguide scenario (i.e., to achieveFigure 5 The signal transmission effect shown in is the target), and the corresponding size arrangement result is calculated.

[0062] like Figure 1 As shown, a connection layer 400 is provided between the substrate structure 200 and the chip body 101, and the connection layer 400 is welded or glued. Specifically, the connection layer 400 between the second dielectric layer 203 and the waveguide 300 in this embodiment is connected by SMT or glue.

[0063] like Figure 6 As shown in the figure, it is a second specific embodiment of the present invention, which is a schematic diagram of the overall structure of the chip-to-waveguide adapter of the annular waveguide. The difference between the first specific embodiment and the present embodiment is that the waveguide tube 300 in this embodiment is an annular waveguide, and the waveguide cavity 301 is a circular through hole. The metallized through hole array 205 is distributed along the ring on the substrate structure 200, and the second dielectric layer 203 is provided with an annular opening 203d matching the shape of the waveguide cavity 301 in the middle, and a long strip of metal connecting piece 203b is provided in the annular opening 203d of the second dielectric layer 203, which is equivalent to a ridge waveguide. The annular metallized through hole array 205, the first dielectric layer 201, and the second dielectric layer 203 form a closed equivalent electromagnetic resonance cavity.

[0064] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present invention to obtain other embodiments based on the several embodiments provided by the present invention, and these embodiments do not exceed the protection scope of the present invention.

[0065] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A chip-to-waveguide switching device, characterized in that: Comprising: a transceiver chip (100); a waveguide (300) located on one side of the transceiver chip (100); a substrate structure (200) located between the transceiver chip (100) and the waveguide (300); the substrate structure (200) includes at least two relatively arranged metal layers and a dielectric substrate (202) located between the at least two metal layers. Among them, the metal layer facing the transceiver chip is connected to the pin (102) of the transceiver chip (100), the metal layer facing the waveguide (300) is connected to the waveguide (300), and the metal layer facing the waveguide (300) is in a hollow shape. A metal connection piece (203b) is provided inside the hollow-shaped metal layer, and the metal connection piece (203b) is connected to the waveguide (300), and the metal connection piece (203b) is equivalent to a waveguide ridge; a signal transmission channel (204) is formed on the substrate structure (200) through all the metal layers and the dielectric substrate (202), and a waveguide cavity (301) corresponding to the position of the signal transmission channel (204) is opened on the waveguide (300).

2. The chip-to-waveguide switching device according to claim 1, characterized in that: One of the at least two metal layers includes a first dielectric layer (201) arranged close to the transceiver chip (100), the first dielectric layer (201) is connected to the pin (102), and the surface of the first dielectric layer (201) is copper-coated; the signal transmission channel (204) includes a first signal transmission port (201a) formed on the first dielectric layer (201).

3. The chip-to-waveguide switching device according to claim 2, characterized in that: The other of the at least two metal layers includes a second dielectric layer (203) arranged close to the waveguide (300), the second dielectric layer (203) is connected to the waveguide (300), and the surface of the second dielectric layer (203) is copper-coated; the signal transmission channel (204) includes a second signal transmission port (203a) formed on the second dielectric layer (203), and the first signal transmission port (201a) and the second signal transmission port (203a) together form both ends of the signal transmission channel (204).

4. The chip-to-waveguide switching device according to claim 3, characterized in that: The second dielectric layer (203) is arranged in parallel with the first dielectric layer (201), and the first signal transmission port (201a) is located at the center of the first dielectric layer (201), and the second signal transmission port (203a) is located at the center of the second dielectric layer (203).

5. The chip-to-waveguide switching device according to claim 3, characterized in that: The signal transmission channel (204) includes a metal signal transmission hole (202a) formed on the dielectric substrate (202), and both ends of the metal signal transmission hole (202a) are arranged opposite to the first signal transmission port (201a) and the second signal transmission port (203a) respectively.

6. The chip-to-waveguide switching device according to claim 5, characterized in that: A copper sheet interface (201b) is provided in the middle of the first dielectric layer (201). The copper sheet interface (201b) is connected to the pin (102), and the first signal transmission port (201a) is opened in the middle of the copper sheet interface (201b); the aperture of the metal signal transmission hole (202a) is the same as that of the first signal transmission port (201a) and the two are concentrically arranged; The second dielectric layer (203) is provided with a metal connecting piece (203b). The metal connecting piece (203b) is connected to the waveguide (300). The second signal transmission port (203a) is opened in the middle of the metal connecting piece (203b). The second signal transmission port (203a) is concentrically arranged with the metal signal transmission hole (202a) and the first signal transmission port (201a) and has the same aperture.

7. The chip-to-waveguide switching device according to claim 6, characterized in that: The second dielectric layer (203) is in a hollow shape. The metal connecting piece (203b) is in a convex stepped shape or a square stepped shape, and the metal connecting piece (203b) extends inward from the inner side wall of one side of the second dielectric layer (203) to the center.

8. The chip-to-waveguide transition device according to any one of claims 5-7, characterized in that The substrate structure (200) is further provided with a metallized via hole array (205) that penetrates through all the metal layers and the dielectric substrate (202). The shape of the metallized via hole array (205) matches the shape of the waveguide cavity (301) and is distributed along the outside of the waveguide cavity (301).

9. The chip-to-waveguide adapter device according to claim 8, characterized in that, The waveguide (300) is a rectangular waveguide, the waveguide cavity (301) is a rectangular through hole, the metallized via hole array (205) is distributed along a rectangle on the substrate structure (200), and a rectangular opening (203c) that matches the shape of the waveguide cavity (301) is opened in the middle of the second dielectric layer (203).

10. The chip-to-waveguide transition device according to claim 8, characterized in that: The waveguide (300) is an annular waveguide, the waveguide cavity (301) is a circular through hole, the metallized via hole array (205) is distributed along an annulus on the substrate structure (200), and an annular opening (203d) that matches the shape of the waveguide cavity (301) is opened in the middle of the second dielectric layer (203).

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