Low-loss vertical transmission transition structure

Abstract

The invention discloses a low-loss vertical transmission transition structure, belongs to the technical field of microwave and millimeter wave circuits, and solves the problem of impedance mismatch in a signal transmission process of an SIP (Session Initiation Protocol) packaging device. A packaging substrate of the SIP packaging device is provided with a non-standard rectangular waveguide, a ball planting type waveguide structure constructed by using the idea that wide and narrow sides of the waveguide are slotted at the same time, a two-order waveguide cavity formed in a multi-layer printed board and a standard rectangular waveguide cavity in a metal waveguide are concentrically arranged from top to bottom; a vertical transmission transition structure is formed by the planting ball type waveguide structure and the two-order waveguide cavity and is used for realizing bidirectional low-loss transition transmission of signals; according to the invention, efficient vertical transmission of signals among the SIP packaging device, the multi-layer printed board and the metal waveguide is realized, the advantages of low transmission loss, simple structure and easy integration are realized, and key technical support is provided for wide application of W-band and terahertz-band SIP devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave and millimeter wave circuits, and in particular relates to a low-loss vertical transmission transition structure. Background Art

[0002] With the development of modern communications and radar technology, microwave spectrum resources are no longer sufficient to meet current demands. For example, 6G mobile communications are planned to utilize millimeter-wave bands, which offer the advantages of both microwaves and infrared. Consequently, an increasing number of applications are seeking to utilize high-end millimeter-wave bands. For example, the W-band (75 GHz to 110 GHz) boasts a spectrum width of up to 35 GHz and a wavelength of 3 mm. W-band radars, with their compact size and high resolution, are being widely researched and applied.

[0003] In recent years, SIP packaging technology has made significant progress in low-end millimeter-wave frequency bands, such as the Ka-band. Furthermore, the technology for vertically transmitting signals from packaged devices to multilayer printed circuit boards (PCBs) using BGAs has also matured. The resolution of these two key issues—SIP devices and BGA vertical transmission transitions—has enabled the widespread application of SIP packaged components in engineering. However, in the W-band, waveguides are often used to transmit signals to reduce losses. Transmission through traditional BGAs introduces significant losses, dramatically exacerbating standing waves and leading to signal distortion, reduced system efficiency, and increased heat dissipation.

[0004] For W-band signal transmission transition structures, existing technologies mostly use microstrip to metal waveguide, SIW (substrate integrated waveguide) / coplanar waveguide to metal waveguide transmission transition. These circuits are limited to application in planar transmission transition of bare chips and cannot solve the vertical signal transmission transition problem of W-band SIP devices in board-level applications.

[0005] Therefore, it is urgent to develop a waveguide-specific board-level vertical transmission transition structure to achieve low-loss vertical transition of W-band signals among SIP, multi-layer printed circuit boards, and metal waveguides, to support the development and application of W-band SIP devices. Summary of the Invention

[0006] The technical solution of the present invention is used to solve the problem of impedance mismatch during signal transmission of a SIP packaged device.

[0007] The present invention solves the above technical problems through the following technical solutions: The present invention provides a low-loss vertical transmission transition structure comprising a non-standard rectangular waveguide provided on a packaging substrate of a SIP packaged device, a ball-type waveguide structure constructed by simultaneously slit- ing the wide and narrow sides of the waveguide, a two-order waveguide cavity provided on a multilayer printed circuit board, and a standard rectangular waveguide cavity in a metal waveguide. The four are concentrically arranged from top to bottom. The ball-type waveguide structure and the two-order waveguide cavity form a vertical transmission transition structure for achieving low-loss transition transmission of signals from the non-standard rectangular waveguide to the standard rectangular waveguide cavity, or from the standard rectangular waveguide cavity to the non-standard rectangular waveguide.

[0008] Furthermore, the bottom of the packaging substrate is welded to the upper opening of the ball-planting waveguide structure.

[0009] Furthermore, the lower opening of the ball-planting waveguide structure is welded to the top of the two-order waveguide cavity.

[0010] Furthermore, the multilayer printed circuit board and the metal waveguide are fixedly connected via positioning pins.

[0011] Furthermore, the length and width of the ball-planting waveguide structure are both larger than those of the non-standard rectangular waveguide.

[0012] Furthermore, the two-order waveguide cavity includes: a first-order waveguide and a second-order waveguide, the first-order waveguide and the second-order waveguide are waveguide cavities with metallized side walls opened on a multilayer printed circuit board, the first-order waveguide is arranged above the second-order waveguide, the first-order waveguide and the second-order waveguide form a step groove shape, and the metallized side walls are metallizedly connected to the ground of the top layer and the bottom layer of the multilayer printed circuit board.

[0013] Furthermore, the SIP package device includes: a top package shell, a package substrate, and a chip. The top package shell covers the package substrate to form a closed space, and the chip is soldered on the package substrate in the closed space.

[0014] Furthermore, the bidirectional transmission path of the signal of the low-loss vertical transmission transition structure is as follows: The signal transmitted by the SIP packaged device is output by the non-standard rectangular waveguide, passes through the ball-planting waveguide structure to reach the two-order waveguide cavity, and finally transmitted to the standard rectangular waveguide cavity; The receiving signal is transmitted from the standard rectangular waveguide cavity to the two-order waveguide cavity, then input into the non-standard rectangular waveguide through the ball-planting waveguide structure, and finally received by the SIP package device.

[0015] Furthermore, the SIP packaged device is one of a low noise amplifier, a filter or a power amplifier.

[0016] Furthermore, the low-loss vertical transmission transition structure is applied to the W band and the terahertz band.

[0017] The beneficial effects of the present invention are as follows: The present invention breaks through the limitations of the traditional BGA transition mode and realizes efficient vertical transmission of signals between SIP packaged devices, multi-layer printed circuit boards and metal waveguides. It has the advantages of low transmission loss, simple structure and easy integration, providing key technical support for the widespread application of SIP devices. It adopts a ball-planting waveguide structure and achieves low-loss signal transmission through the equivalent method of simultaneous slits on the wide and narrow sides, breaking through the thinking limitations of traditional waveguide modes. The two-order waveguide cavity design on the multi-layer printed circuit board solves the impedance mismatch problem in the signal transmission path, significantly improves the standing wave performance, and enhances the system efficiency and signal quality. In the frequency band of 90GHz to 98GHz, the transmission loss is ≤0.02dB, which is far superior to the traditional BGA transition mode and meets the strict requirements of high-frequency signal transmission. It cleverly utilizes the existing SIP package and multi-layer printed circuit board structure to realize vertical transmission transition, with a simple structure and easy engineering application. It solves the technical bottleneck of vertical signal transition of SIP devices in board-level applications and promotes the widespread application of W-band and terahertz band packaged devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 2 is an exploded view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 3 is a front view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 4 is a side view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 5 is a front cross-sectional view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 6 is a front oblique cross-sectional view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 7 is a side sectional view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 8 is a side sectional oblique view of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 9 This is a diagram showing the arrangement and size design of high-lead balls in a ball-planting waveguide structure of the W band according to an embodiment of the present invention; Figure 10 2. Dimensional design diagram of a two-stage waveguide cavity in the W band according to an embodiment of the present invention; Figure 11 2. It is a schematic diagram of a bidirectional signal transmission path of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 12 2. It is a simulation model diagram of a low-loss vertical transmission transition structure according to an embodiment of the present invention; Figure 13 1 is a diagram showing simulation results of a low-loss vertical transmission transition structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments: Example 1 The embodiment of the present invention takes the vertical transmission transition in the W band (center frequency of 94 GHz) as an example to specifically introduce the design of a board-level low-loss vertical transmission transition structure of a ball-planted waveguide. The board-level low-loss vertical transmission transition structure of a ball-planted waveguide in the embodiment of the present invention is also effective for other frequency bands, for example, it can be applied to terahertz bands such as the D band (110 GHz to 170 GHz) and the G band (140 GHz to 220 GHz).

[0021] like Figures 1 to 4 As shown, the board-level low-loss vertical transmission transition structure of the ball-planting waveguide according to the embodiment of the present invention includes: a SIP package device 10, a ball-planting waveguide structure 20, a multilayer printed circuit board 30 and a metal waveguide 40.

[0022] The SIP packaged device 10 includes a top package housing 101, a package substrate 102, and a chip. The top package housing 101 covers the package substrate 102 to form a sealed space. The chip is soldered to the package substrate 102 within the sealed space. The chip is used to generate a W-band signal. The SIP packaged device 10 can be a low-noise amplifier, a filter, or a power amplifier.

[0023] like Figures 5 to 8 As shown, the package substrate 102 of the SIP package device 10 is provided with a transparent non-standard rectangular waveguide 103. The interior of the metal waveguide 40 is a BJ900 standard rectangular waveguide cavity 401.

[0024] like Figure 9As shown, the ball-planting waveguide structure 20 is formed by 14 0.4mm diameter high-lead balls enclosing a rectangular waveguide cavity. These 14 high-lead balls are arranged along the bottom opening of the non-standard rectangular waveguide 103 to form a rectangular waveguide cavity. The high-lead balls are evenly arranged with 6 wide edges and 3 narrow edges, and the ball spacing is 0.65mm. The length and width of the ball-planting waveguide structure 20 are both larger than those of the non-standard rectangular waveguide 103. The design concept of the ball-planting waveguide structure 20 is to utilize the concept of simultaneous slits on the wide and narrow sides of the waveguide. Compared to standard rectangular waveguides, the ball-planting waveguide structure 20 formed by the high-lead balls breaks through the traditional waveguide model concept and adopts the equivalent method of simultaneous slits on the wide and narrow sides to achieve W-band signal transmission. The high-lead ball is a metal ball. The diameter d and the ball spacing s of the metal ball have a great influence on the electrical performance. Theoretically, the denser the metal balls are arranged, the closer the side wall of the waveguide-like structure is to the ideal electrical plane, and the smaller the transmission loss of the waveguide-like structure is. However, considering the actual engineering application, the diameter of the high-lead ball is designed to be 0.4mm and the ball spacing is 0.65mm. While it is easy to implement welding and other processes, the transmission loss is close to that of the rectangular waveguide. The wide side a' and narrow side b' of the ball-planted waveguide formed can be calculated to be equivalent to the standard rectangular waveguide.

[0025] The propagation mode of the ball-planting waveguide structure 20 is TE n0 mode, the main mode of rectangular waveguide is TE 10 When the signal is transmitted from the non-standard rectangular waveguide 103 to the ball-planting waveguide structure 20, since the length and width of the ball-planting waveguide structure 20 are larger than those of the non-standard rectangular waveguide 103, the signal in the transmission path suddenly changes, generating a high-order mode. For this reason, it is necessary to design an impedance matching structure to reduce the port standing wave and transmission loss, and achieve a low-loss transition from the ball-planting waveguide structure 20 to the metal waveguide 40.

[0026] The reasons why the length and width dimensions of the ball-planting waveguide structure 20 are both larger than those of the non-standard rectangular waveguide 103 are: first, due to the demand for miniaturization of the SIP packaging device 10, the size of the non-standard rectangular waveguide 103 is often smaller; second, in order to facilitate welding, a certain distance must be maintained between the multiple high lead balls of the ball-planting waveguide structure 20, which results in the length and width dimensions of the ball-planting waveguide structure 20 being both larger than those of the non-standard rectangular waveguide 103.

[0027] like Figures 5 to 8 As shown, a two-step waveguide cavity in the shape of a step groove is provided on the multilayer printed circuit board 30. The two-step waveguide cavity includes: a first-step waveguide 301 and a second-step waveguide 302. The first-step waveguide 301 and the second-step waveguide 302 are waveguide cavities with metallized sidewalls provided on the multilayer printed circuit board. The first-step waveguide 301 is provided above the second-step waveguide 302. The first-step waveguide 301 and the second-step waveguide 302 form a step groove shape. The metallized sidewalls are metallized to the ground of the top and bottom layers of the multilayer printed circuit board.

[0028] The bottom of the packaging substrate 102 is welded to the upper opening of the ball-planting waveguide structure 20, and the lower opening of the ball-planting waveguide structure 20 is welded to the top of the two-order waveguide cavity. The multilayer printed circuit board and the metal waveguide 40 are fixedly connected by positioning pins. The non-standard rectangular waveguide 103, the ball-planting waveguide structure 20, the first-order waveguide 301, the second-order waveguide 302, and the BJ900 standard rectangular waveguide cavity 401 are concentrically arranged from top to bottom.

[0029] The multilayer printed circuit board is the carrier of the SIP packaged device 10. The SIP packaged device 10 is soldered to the multilayer printed circuit board via the ball-planting waveguide structure 20. The original function of the multilayer printed circuit board is to provide power, control signals, etc. to the SIP packaged device 10. In the embodiment of the present invention, a two-order matching waveguide cavity is further designed on the multilayer printed circuit board, which cleverly utilizes the existing multilayer printed circuit board and achieves low-loss signal transition.

[0030] like Figure 10 As shown, for the W band (90 GHz to 98 GHz), the length, width, and depth of the first-order waveguide 301 are 2.5 mm × 0.6 mm × 0.75 mm, and the length, width, and depth of the second-order waveguide 302 are 3 mm × 1.6 mm × 0.85 mm, and the chamfer radius of both is 0.3 mm.

[0031] like Figure 11 As shown, the red lines represent the bidirectional signal transmission path. When the SIP packaged device transmits a signal, the signal emitted by the SIP packaged device 10 is output from the non-standard rectangular waveguide 103, passes through the ball-type waveguide structure 20, reaches the first-order waveguide 301 and the second-order waveguide 302, and finally is transmitted to the BJ900 standard rectangular waveguide cavity 401. When the SIP packaged device receives a signal, the received signal is transmitted from the BJ900 standard rectangular waveguide cavity 401 to the second-order waveguide 302 and the first-order waveguide 301, then passes through the ball-type waveguide structure 20 and is input into the non-standard rectangular waveguide 103, and finally is received by the SIP packaged device 10.

[0032] like Figure 12 and Figure 13 As shown in the figure, the simulation model and simulation results of the board-level vertical transmission transition structure based on the ball-planting waveguide of the present invention are shown. Figure 13 It can be seen that within the operating frequency band of 90 GHz to 98 GHz, the transmission loss of the board-level vertical transmission transition structure based on the ball-planting waveguide of the present invention is ≤ 0.02 dB, achieving a low-loss transmission transition in the W band.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A low-loss vertical transmission transition structure, characterized in that: A non-standard rectangular waveguide (103) provided on a packaging substrate (102) of a SIP packaged device (10), a ball-planting waveguide structure (20) constructed by simultaneously opening the wide and narrow sides of the waveguide, a two-order waveguide cavity provided on a multilayer printed circuit board (30), and a standard rectangular waveguide cavity (401) in a metal waveguide (40) are concentrically arranged from top to bottom; the ball-planting waveguide structure (20) and the two-order waveguide cavity form a vertical transmission transition structure for realizing low-loss transition transmission of signals from the non-standard rectangular waveguide (103) to the standard rectangular waveguide cavity (401), or from the standard rectangular waveguide cavity (401) to the non-standard rectangular waveguide (103).

2. The low-loss vertical transmission transition structure according to claim 1, characterized in that: The bottom of the packaging substrate (102) and the upper opening of the ball-planting waveguide structure (20) are welded together.

3. The low-loss vertical transmission transition structure according to claim 2, characterized in that: The lower end opening of the ball-planting waveguide structure (20) is welded to the top of the two-order waveguide cavity.

4. The low-loss vertical transmission transition structure according to claim 3, characterized in that: The multilayer printed circuit board (30) and the metal waveguide (40) are fixedly connected via positioning pins.

5. The low-loss vertical transmission transition structure according to claim 1, characterized in that: The length and width of the ball-planting waveguide structure (20) are both larger than those of the non-standard rectangular waveguide (103).

6. The low-loss vertical transmission transition structure according to claim 1, characterized in that: The two-order waveguide cavity comprises: a first-order waveguide (301) and a second-order waveguide (302); the first-order waveguide (301) and the second-order waveguide (302) are waveguide cavities with metallized side walls opened on a multilayer printed circuit board; the first-order waveguide (301) is arranged above the second-order waveguide (302); the first-order waveguide (301) and the second-order waveguide (302) form a stepped groove shape; the metallized side walls are metallizedly connected to the ground of the top layer and the bottom layer of the multilayer printed circuit board.

7. The low-loss vertical transmission transition structure according to claim 1, characterized in that: The SIP package device (10) comprises: a top package shell (101), a package substrate (102), and a chip; the top package shell (101) covers the package substrate (102) to form a closed space; and the chip is welded on the package substrate (102) in the closed space.

8. The low-loss vertical transmission transition structure according to claim 1, characterized in that: The bidirectional transmission path of the signal is as follows: The signal emitted by the SIP package device (10) is output by the non-standard rectangular waveguide (103), passes through the ball-planting waveguide structure (20) to reach the two-order waveguide cavity, and is finally transmitted to the standard rectangular waveguide cavity (401); The received signal is transmitted from the standard rectangular waveguide cavity (401) to the two-order waveguide cavity, then input into the non-standard rectangular waveguide (103) through the ball-planting waveguide structure (20), and finally received by the SIP package device (10).

9. The low-loss vertical transmission transition structure according to claim 1, characterized in that: The SIP packaged device (10) is one of a low noise amplifier, a filter or a power amplifier.

10. The low-loss vertical transmission transition structure according to claim 1, characterized in that: Applicable to W-band and terahertz band.

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