Micro-coaxial bi-directional coupler with ultra-wideband performance and packaging structure of micro-coaxial bi-directional coupler

Abstract

The invention provides a micro-coaxial bi-directional coupler with ultra-wideband performance and a packaging structure thereof, and belongs to the technical field of microwave and millimeter wave communication, the micro-coaxial bi-directional coupler comprises two ultra-wideband micro-coaxial single-directional couplers, and a micro-coaxial coupling line is a multi-section coupling line with continuously changing impedance; the first ends of the two single directional couplers are provided with narrow-edge Y-shaped junctions, the second ends of the two single directional couplers are provided with wide-edge Y-shaped junctions, two coaxial ports of the first ends of the two single directional couplers are cascaded through the narrow-edge Y-shaped junctions, and the other two coaxial ports are used as load ports; the distance and the cross section of the first-end micro-coaxial coupling line are smaller than those of the second-end micro-coaxial coupling line, and four coaxial ports of the second ends of the two single-directional couplers serve as an input port, an output port, a coupling port and an isolation port of the double-directional coupler; the axis of the load port is perpendicular to the plane where the axes of the four coaxial ports of the second end are located. And the high-performance coupler performance is realized, and miniaturized packaging is realized at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave and millimeter-wave communication, and particularly to a micro coaxial dual directional coupler with ultra-wideband performance and its packaging structure. Background Art

[0002] With the rapid development of millimeter-wave communication in the fields of 5G / 6G, radar, and high-speed interconnection, its wide frequency band and high-precision characteristics pose stringent requirements for device testing. As a core test tool, a vector network analyzer needs to cover the full-band measurement capability from low frequency to high frequency to adapt to the R & D and verification requirements of multi-scenario and multi-mode devices.

[0003] Currently, the mainstream vector network analyzer system still adopts a cascaded architecture of "host + waveguide frequency extension module" to achieve high-frequency band extension. However, the high-pass characteristic of waveguide devices results in the system being able to only test frequency bands above 67 GHz. If it is necessary to cover low-frequency bands such as 10 MHz to 67 GHz, the frequency extension module needs to be removed and a sub-band test link needs to be rebuilt. Such sub-band operations not only greatly increase the calibration complexity and time cost but also accelerate the wear of coaxial interfaces due to frequent plugging and unplugging. In view of the urgent demand for full-band integrated measurement, an architecture of "host + extension machine + frequency extension module" has been proposed. Therefore, developing a miniaturized, highly directional dual directional coupler that covers the ultra-wideband from 10 MHz to 120 GHz and 145 GHz has become a necessary hardware support for solving the above problems.

[0004] Moreover, to achieve the ultra-wideband high performance and three-dimensional packaging of a micro coaxial dual directional coupler at high frequency bands, it is necessary to provide a miniaturized topology structure, design, and integration scheme of a micro coaxial dual directional coupler based on standard connectors. Summary of the Invention

[0005] To solve the above problems, the present invention provides a micro coaxial dual directional coupler with ultra-wideband performance, and provides two packaging structures of the micro coaxial dual directional coupler with ultra-wideband performance, aiming to achieve miniaturized packaging while realizing a high-performance micro coaxial ultra-wideband dual directional coupler.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: A micro coaxial double directional coupler with ultra-wideband performance, which includes two ultra-wideband micro coaxial single directional couplers. Among them, the micro coaxial coupling line of the ultra-wideband micro coaxial single directional coupler is a multi-section tapered coupling line with continuously changing impedance; narrow-side Y-junctions are provided at the first ends of the two single directional couplers, and wide-side Y-junctions are respectively provided at the second ends of the two single directional couplers. The two coaxial ports at the first ends of the two single directional couplers are cascaded through the narrow-side Y-junction, and the other two coaxial ports are used as load ports; the spacing and cross-section of the micro coaxial coupling line at the first end are smaller than those of the micro coaxial coupling line at the second end. The four coaxial ports at the second ends of the two single directional couplers serve as the input port, output port, coupling port, and isolation port of the double directional coupler; the axis of the load port is perpendicular to the plane where the axes of the four coaxial ports at the second end are located.

[0007] Furthermore, the micro coaxial double directional coupler includes an inner conductor, an outer conductor, and a dielectric support strip. The load port includes a first load port and a second load port; the outer conductor is hollow, and the inner conductor is suspended in the outer conductor through a plurality of axially arranged dielectric support strips; the inner conductor includes a first micro coaxial coupling line, a second micro coaxial coupling line, a third micro coaxial coupling line, and a Y-junction. The input port, the first micro coaxial coupling line, the output port, the coupling port, the second micro coaxial coupling line, and the second load port form a single directional coupler; the input port, the first micro coaxial coupling line, the output port, the isolation port, the third micro coaxial coupling line, and the first load port form a single directional coupler. The input port and the output port are located on the first micro coaxial coupling line, the coupling port and the second load port are located on the second micro coaxial coupling line, and the isolation port and the first load port are located on the third micro coaxial coupling line.

[0008] Furthermore, the first ends of the two single directional couplers are bent into a C shape and nested with each other's topological structures; one port of the narrow-side Y-junction is connected through a cascaded transition coaxial line, and the first micro coaxial coupling line serving as the main path transmission line becomes an integral body. The included angle between two adjacent ports of the wide-side Y-junction is 90°.

[0009] Furthermore, 1mm coaxial connectors or 0.8mm coaxial connectors are provided at the input port, output port, coupling port, isolation port, and the two load ports. The ultra-wideband micro coaxial single directional coupler is formed based on the metal additive manufacturing process, and is formed by an eight-layer process. The thickness of the dielectric support strip is 0.04mm.

[0010] Furthermore, when a 1.0mm coaxial connector is provided, the forming height of the fifth layer h sp is increased by a set value, and the height of the inner conductor h inner1Correspondingly, increase a value equal to the set value to change the characteristic impedance after the micro coaxial coupler is converted into a coaxial cable through the Y-junction at the second end; at the narrow-side Y-junction position, the outer conductor matching structure is set as a three-layer stepped matching structure, and the inner conductor gradually changes to a wider size to form a tapered inner conductor structure.

[0011] Furthermore, when setting the 0.8 mm coaxial connector, the height of each layer h av is 100 μm; the height of the micro coaxial coupler h inner2 is 0.2 mm.

[0012] Furthermore, at the dielectric support bar, reduce the width of the inner conductor to form a coupling line compensation structure.

[0013] Furthermore, the input port, output port, coupling port, and isolation port are all set with GSG interfaces.

[0014] Furthermore, the load port adopts a micro coaxial built-in integrated load.

[0015] The present invention also provides a micro coaxial dual directional coupler packaging structure, including an upper cover plate and a lower cover plate. There is a groove for accommodating the micro coaxial dual directional coupler as described above between the upper cover plate and the lower cover plate, and the planar shape of the groove is consistent with the planar projection of the micro coaxial dual directional coupler; the depth of the groove is consistent with the thickness of the micro coaxial dual directional coupler.

[0016] Furthermore, at the positions on the upper cover plate and the lower cover plate corresponding to the ports of the micro coaxial dual directional coupler, coaxial connectors are set through side plates. The side plates are fixedly connected to the upper cover plate and the lower cover plate by screws, and through holes are opened at the positions on the upper cover plate corresponding to the load ports of the micro coaxial dual directional coupler.

[0017] Furthermore, semi-cylindrical grooves are opened at the positions on the upper cover plate and the lower cover plate corresponding to the horizontal ports of the micro coaxial dual directional coupler, and through holes are opened at the positions on the upper cover plate corresponding to the load ports.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: The present invention provides a miniaturized micro coaxial dual directional coupler with ultra-wideband performance, which can realize the extraction and separation of two signals. Moreover, the micro coaxial ultra-wideband dual directional coupler and the interface matching design are comprehensively considered to ensure the impedance continuity at the ports before and after the transformation from the micro coaxial coupler to the coaxial cable. The six ports of the micro coaxial ultra-wideband dual directional coupler include four horizontally connected ports and two vertically connected ports, all of which can be directly in contact with standard connectors. The structure is compact and does not require welding. The packaging structure of the present invention based on the micro coaxial ultra-wideband dual directional coupler chip and the connector has a small volume and is easy to assemble, providing the core underlying hardware support for realizing a miniaturized and high-performance ultra-wideband vector network analyzer.

[0019] Further, when the six ports are all connected to equivalent 1.0 mm coaxial connectors, the simulation results show good return loss and low insertion loss within 10M - 120 GHz, and good working performance within the operating frequency band. The return loss of the input and output ports is less than 19 dB, the directivity is greater than 20 dB, and the insertion loss is less than 2.5 dB. When the six ports are all connected to equivalent 0.8 mm coaxial connectors, the simulation results also show good return loss and low insertion loss within 10M - 150 GHz, and good working performance within the operating frequency band. The return loss of the input and output ports is less than 14 dB, the directivity is greater than 18 dB, and the insertion loss is less than 3 dB.

[0020] Further, the first ends of the two micro coaxial single - directional couplers are bent into a C - shape and nested with each other's topological structures; one port of the narrow - side Y - junctions of the two micro coaxial single - directional couplers is connected through a cascaded transition coaxial line. The first micro coaxial coupling line serving as the main - path transmission line becomes an integral body, and the included angle between two adjacent ports of the wide - side Y - junction is 90°; a continuously - varying and curved topological structure is adopted, and the odd - and even - mode impedances show continuous changes with small discontinuities, which can reduce the return loss. The curved and in - rolled topological structure greatly reduces the aspect ratio of the micro coaxial bi - directional coupler, improves the yield rate of the micro coaxial bi - directional coupler processing, and also reduces the layout area of the micro coaxial bi - directional coupler, making the chip area of the micro coaxial ultra - wideband bi - directional coupler within 1 cm × 2 cm, and reducing the processing cost.

[0021] Further, the six ports of the first type of micro coaxial bi - directional coupler can be directly connected to 1.0 mm coaxial connectors to realize the function of the ultra - wideband bi - directional coupler. The working frequency range is DC~120 GHz, achieving an input - port return loss of more than 19 dB, a directivity of more than 20 dB, and an insertion loss within 2.5 dB; the six ports of the second type of micro coaxial bi - directional coupler can be directly connected to 0.8 mm coaxial connectors, also realizing the function of the ultra - wideband bi - directional coupler. The working frequency is from DC to 145 GHz, achieving an input - port return loss of more than 14 dB, a directivity of more than 18 dB, and an insertion loss within 3 dB.

[0022] Further, the first type of micro coaxial bi - directional coupler is designed based on an eight - layer forming process, and the total thickness is 0.8 mm; the average forming height of each layer h av is 100 μm. The inner - conductor size is comprehensively designed according to the coupling degree, and the height of the inner conductor of the micro coaxial ultra - wideband bi - directional coupler is changed by process adjustment. The forming height of the fifth layer is finely adjusted by the forming process h sp to adjust the height of the inner conductorh inner1 The value makes the characteristic impedance of the micro coaxial coupled line closer to 50 ohms after being converted into a coaxial cable through a wide-side Y-junction, eliminating the reflection caused by impedance mismatch during the conversion of the input and output ports from coaxial to connector, improving the return loss of the input and output ports, and reducing the return loss of the input and output ports; without deteriorating other performances of the micro coaxial ultra-wideband double directional coupler, it reduces impedance discontinuity, achieves a return loss of more than 19 dB at the input port, and the operating frequency reaches 120 GHz.

[0023] Furthermore, the dielectric support strip is made of the photosensitive organic material SU8. The dielectric support strip is a rectangular strip that straddles and is embedded between the inner conductor and the outer conductor, supporting the inner conductor to make the inner conductor suspended in the outer conductor, and the dielectric support strips are arranged periodically; the air medium and the relatively thin dielectric support SU-8 of the micro coaxial transmission line reduce dielectric loss and dispersion, and the TEM mode transmission ensures a relatively high cut-off operating frequency.

[0024] Furthermore, a compensation structure is designed at the loading position of the inner conductor coupled line on the dielectric support strip, narrowing the width of the inner conductor, correcting the adverse effect of the dielectric support strip on the impedance continuity of the odd and even modes of the coupled line, reducing the parasitic coupling brought by the dielectric support strip to the coupled line, and ensuring the excellent directivity performance of the micro coaxial ultra-wideband double directional coupler.

[0025] Furthermore, an outer conductor matching structure and a tapered inner conductor structure are arranged at the narrow-side Y-junction. Due to the relatively close distance between the inner conductors at the narrow-side Y-junction, the matching structure inside the outer conductor is likely to affect the coupling performance of the micro coaxial ultra-wideband double directional coupler. A three-layer stepped matching structure is adopted for the outer conductor at the narrow-side Y-junction to balance the return loss and coupling performance, reducing the higher-order modes generated when the coupled transmission line at the narrow-side Y-junction changes to a coaxial transmission line, optimizing the return loss and directivity of the micro coaxial ultra-wideband double directional coupler at high frequencies, enabling the micro coaxial ultra-wideband double directional coupler to maintain a stable coupling degree within the operating frequency band. Also, due to the relatively small width of the micro coaxial coupled line, it has an adverse effect on the size matching and mechanical strength performance of the load port. Therefore, the inner conductor gradually changes to a wider size at the narrow-side Y-junction; the widths of the inner conductors of the two narrow-side Y-junctions are gradually widened while being bent by 45°, reducing the impedance discontinuity at the Y-junction.

[0026] Furthermore, the second micro coaxial double directional coupler is designed based on the standard process of an eight-layer micro coaxial transmission line, and the forming height of each layer h av is 100 μm, the thickness of the support strip SU-8 h SU8 is 40 μm and it is located above the fourth layer. The cross-sectional height of the micro coaxial coupled line hinner2 The layer thickness is 0.2 mm, and the layer thickness of 0.1 mm makes the overall structure thickness more evenly distributed along the deposition direction, eliminating the need to re - design process parameters and reducing the manufacturing difficulty.

[0027] Furthermore, the load port can adopt a micro - coaxial built - in integrated load, further reducing the package volume of the chip.

[0028] Furthermore, by setting GSG interfaces at the input port, output port, coupling port, and isolation port, the integration of the micro - coaxial coupler and the MMIC system can be achieved through wire bonding, improving the miniaturization and integration of the system.

[0029] The present invention provides two micro - coaxial dual - directional coupler package structures. The first package structure is a flange - type connector that uses pins to position the horizontal - direction connector. The connector is directly connected to the micro - coaxial dual - directional coupler, with a smaller package area and small assembly error. The second package fixture is a limiter - type structure formed by the upper cover plate and the lower cover plate. Semi - cylindrical channels are opened on the upper cover plate and the lower cover plate to accommodate and position the cylindrical part of the connector inserted into the package structure, which can also realize the connection between the connector and the ports of the micro - coaxial dual - directional coupler, with a smaller package thickness.

[0030] Furthermore, the pin holes on the package structure are used to position the micro - coaxial dual - directional coupler, and the package structure can cooperate with the positioning pins on the coaxial connector to fix the position of the coaxial connector, enabling the interfaces of the micro - coaxial dual - directional coupler to be accurately connected to the connector. The coaxial connector is set through the side plate to realize the disassembly and connection between components. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the prior art solutions, the following will briefly introduce the drawings used in the embodiments or the prior art solutions. It should be noted that the following - described drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a front - view detail diagram of a micro - coaxial ultra - wideband dual - directional coupler A based on a 1.0 - mm coaxial connector package provided by an embodiment of the present invention; Figure 2 It is a front - view perspective diagram of a micro - coaxial ultra - wideband dual - directional coupler A based on a 1.0 - mm coaxial connector package provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of an eight - layer micro - coaxial process used for a micro - coaxial ultra - wideband dual - directional coupler A based on a 1.0 - mm coaxial connector package provided by an embodiment of the present invention; Figure 4Schematic diagram of the coupling line compensation structure of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 5 Front cross-sectional view of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 6 Oblique axonometric view of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 7 S 11 Parameter simulation results of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 8 S 21 Simulation results of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 9 S 31 Simulation results of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 10 Directivity simulation results of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; Figure 11 Structural diagram of the packaging fixture of a micro coaxial ultra-wideband bi-directional coupler A based on a 1 mm flange-type connector package provided by an embodiment of the present invention; Figure 12 Exploded view of the packaging structure of a micro coaxial ultra-wideband bi-directional coupler A based on a 1 mm flange-type connector package provided by an embodiment of the present invention; Figure 13 Schematic diagram of the eight-layer micro coaxial process used for a micro coaxial ultra-wideband bi-directional coupler A based on a 0.8 mm coaxial connector package provided by an embodiment of the present invention; Figure 14 Front detail view of a micro coaxial ultra-wideband bi-directional coupler B based on a 0.8 mm coaxial connector package provided by an embodiment of the present invention; Figure 15 Oblique axonometric view of a micro coaxial ultra-wideband bi-directional coupler B based on a 0.8 mm coaxial connector package provided by an embodiment of the present invention; Figure 16 Structural diagram of the limiter-type packaging fixture of a micro coaxial ultra-wideband bi-directional coupler B based on a 0.8 mm coaxial connector package provided by an embodiment of the present invention; Figure 17 Explosion diagram of the packaging structure of a micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by an embodiment of the present invention; Figure 18 S of a micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by an embodiment of the present invention 11 simulation result; Figure 19 S of a micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by an embodiment of the present invention 21 simulation result; Figure 20 S of a micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by an embodiment of the present invention 31 simulation result; Figure 21 Directivity simulation result of a micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by an embodiment of the present invention.

[0033] In the drawings, 1, input port; 2, output port; 3, coupling port; 4, isolation port; 5, first load port; 6, second load port; 7, outer conductor; 8, first micro - coaxial coupling line; 9, second micro - coaxial coupling line; 10, third micro - coaxial coupling line; 11, dielectric support bar; 12, coupling line compensation structure; 13, narrow - side Y - junction; 14, wide - side Y - junction; 15, cascaded transition coaxial line; 16, outer conductor matching structure; 17, tapered inner conductor structure; 18, equivalent 1.0mm coaxial connector; 19, positioning pin hole; 20, upper cover plate; 21, lower cover plate; 22, cover plate positioning pin; 23, screw; 24, 1.0mm coaxial connector; 25, equivalent 0.8mm coaxial connector; 26, 0.8mm coaxial connector. Detailed implementation manners

[0034] To make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It should be noted that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0035] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "top surface", "bottom surface", "left side", "right side", "horizontal direction", and "vertical direction" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, and should not be construed as indicating that the indicated elements or devices are in a specific orientation.

[0036] In the single-directional coupler of the present invention, 80 sections of tapered coupling lines with continuously varying impedance are used. After bending and cascading, they are integrally processed. By using the air medium of the micro-coaxial process, less dielectric loss and dispersion are achieved, and high directivity is realized. The upper limit of the operating frequency of the micro-coaxial double-directional coupler is as high as 150 GHz. Moreover, by using the high shielding property of the micro-coaxial transmission line, high-density wiring and a smaller chip area of the micro-coaxial double-directional coupler are realized. Compared with similar products, the operating frequency band width is further expanded, the directivity performance is improved, and direct coupling and transmission of low-frequency to high-frequency signals (10 MHz to 120 GHz and 145 GHz) are realized within a single module, while maintaining a high directivity index of >20 dB. The micro-coaxial ultra-wideband double-directional coupler of the present invention can be directly embedded in the mainframe of a vector network analyzer or a spread-spectrum module, significantly reducing the system complexity and improving the measurement efficiency, providing hardware support for the ultra-wideband high-precision testing of millimeter-wave devices and filling the domestic technical gap in related fields.

[0037] Based on the eight-layer micro-coaxial process, the present invention designs two types of miniaturized and high-performance ultra-wideband double-directional coupler chips, with six designed ports. Four horizontal ports are respectively the input port 1, output port 2, coupling port 3, and isolation port 4, and the other two vertical ports are load ports, which can be connected to 1.0 mm or 0.8 mm coaxial connectors and can respectively operate at 10 MHz to 120 GHz and 10 MHz to 145 GHz. Based on these two types of micro-coaxial ultra-wideband double-directional coupler chips, two types of packaging fixtures are respectively designed, each including upper and lower fixtures, and miniaturized integrated packaging of the two types of micro-coaxial chips is realized.

[0038] Example 1, please refer to Figure 1 , a front detailed view of a micro-coaxial ultra-wideband double-directional coupler A encapsulated based on a 1.0 mm coaxial connector provided by the embodiment of the present invention; it includes a rectangular coaxial interface in the horizontal direction and two circular coaxial interfaces in the vertical direction. The rectangular coaxial interface in the horizontal direction includes the input port 1, output port 2, coupling port 3, and isolation port 4, and the two circular coaxial interfaces in the vertical direction include the first load port 5 and the second load port 6; the impedance of all six ports is 50 ohms for connecting a 1.0 mm coaxial connector.

[0039] Please refer to Figure 2, A front perspective view of a micro coaxial ultra-wideband dual directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention; the micro coaxial ultra-wideband dual directional coupler based on a 1.0 mm coaxial connector package includes a bent outer conductor 7, a micro coaxial coupling line, and a Y-junction. The Y-junction is a coupling line - coaxial line transition structure; the micro coaxial coupling line includes a first micro coaxial coupling line 8, a second micro coaxial coupling line 9, and a third micro coaxial coupling line 10. The micro coaxial coupling line is the inner conductor. The micro coaxial coupling line performs mode conversion through the Y-junction to achieve the coupling line - coaxial line transition. Among them, the first micro coaxial coupling line 8, the second micro coaxial coupling line 9, the input port 1, the output port 2, the coupling port 3, and the second load port 6 form a single directional coupler. The first micro coaxial coupling line 8, the third micro coaxial coupling line 10, the input port 1, the output port 2, the isolation port 4, and the first load port 5 form a single directional coupler. Both single directional couplers are formed by bending an asymmetric tapered coupling line. The micro coaxial coupling line gradually tapers from one end to the other end. Therefore, two Y-junctions are correspondingly provided: namely, a narrow-side Y-junction 13 and a wide-side Y-junction 14. The end with a thinner inner conductor is the narrow-side Y-junction 13, and the end with a thicker inner conductor is the wide-side Y-junction 14. Among them, one coaxial port of the narrow-side Y-junction 13 of the single directional coupler is connected to one coaxial port of the narrow-side Y-junction 13 of the other single directional coupler through a section of cascaded transition coaxial line 15 to form the first micro coaxial coupling line 8 of the main path transmission line of the micro coaxial ultra-wideband dual directional coupler; the remaining two coaxial ports of the narrow-side Y-junction 13 are bent at 45° in continuously different directions and are used to connect two load ports, namely, the first load port 5 and the second load port 6. Specifically, they are connected to the connector and then externally connected to the load. In addition, the inner conductor of the wide-side Y-junction 14 is wider, and the mechanical properties of the rectangular coaxial port at the wide-side Y-junction 14 are stronger. Therefore, the rectangular coaxial port of the wide-side Y-junction 14 is horizontally connected to the connector and used as the input port 1, the output port 2, the coupling port 3, and the isolation port 4 of the dual directional coupler. The characteristic impedance of the coaxial port converted by the wide-side Y-junction 14 is determined by the width of the inner conductor near the port and the distance between the inner conductor and the outer conductor 7 near the port. In order to facilitate the packaging of the connector interface, after separating the coupling lines at the wide-side Y-junction 14, they are respectively bent at 45° and then respectively connected to the input port 1, the output port 2, the coupling port 3, and the isolation port 4, so that the included angle between two adjacent ports is 90°, and the directions of the four horizontal coaxial interfaces are 90° to each other two by two, which is convenient for use after being horizontally connected to the coaxial connector.

[0040] The two load ports are circular coaxial interfaces and can be externally connected to coaxial loads by vertically connected coaxial connectors; the combined application of horizontal and vertical coaxial ports ensures the feasibility of the packaging design and also reduces the area of the chip.

[0041] As an alternative embodiment, GSG interfaces are provided at the input port 1, output port 2, coupling port 3, and isolation port 4, and the integration of the micro-coaxial ultra-wideband bi-directional coupler and the MMIC system can be achieved by wire bonding.

[0042] Please refer to Figure 3 , which shows the schematic diagram of the eight-layer process used for the micro-coaxial ultra-wideband bi-directional coupler A based on the 1.0mm coaxial connector package according to the embodiments of the present invention; it includes an inner conductor, an outer conductor 7, and a dielectric support bar 11. The inner conductor includes a first micro-coaxial coupling line 8, a second micro-coaxial coupling line 9, a third micro-coaxial coupling line 10, and a Y-junction. The outer conductor 7 is arranged outside the inner conductor, and the dielectric support bar 11 is embedded between the inner conductor and the outer conductor 7 and is a slender rectangle. The dielectric support bar 11 passes through the inner conductor, and the inner conductor is suspended inside the outer conductor 7 through the dielectric support bar 11. The outer conductor 7 can be formed in eight layers with a total thickness of 0.8mm. The dielectric support bar 11 is located in the fifth layer, and the thickness of the dielectric support bar 11 h SU8 = 0.04mm. Through TDR analysis, if the thickness of each layer in the forming process is 100μm, the characteristic impedance of the coaxial port corresponding to the wide-side Y-junction 14 of the micro-coaxial ultra-wideband bi-directional coupler is 55 ohms, while the impedance at the circular coaxial interface is 50 ohms. If the impedance matching of the port is achieved by increasing the gradual length of the coaxial line, the chip area will increase, and the return loss of the input port 1 will also deteriorate inherently due to impedance discontinuity. In the present invention, by adjusting the processing technology of the sixth layer of the first micro-coaxial coupling line 8 at the wide-side Y-junction 14, the height of the inner coaxial is increased by 40μm, so that the impedance of the coaxial port output by the wide-side Y-junction 14 is directly 50 ohms. When matching with the coaxial connector, there will only be structural discontinuity, and the impedance discontinuity is reduced. After design, the return loss of the input port 1 reaches below 20dB, and the directivity is also improved, achieving very good results.

[0043] Please refer to Figure 4, a schematic diagram of a coupled line compensation structure 12 of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package according to an embodiment of the present invention, taking a first micro coaxial coupled line 8 and a third micro coaxial coupled line 10 as examples; a dielectric support bar 11 spanning between the first micro coaxial coupled line 8 and the second micro coaxial coupled line 9 and between the first micro coaxial coupled line 8 and the third micro coaxial coupled line 10 increases the parasitic capacitance between the micro coaxial coupled lines and has a destructive effect on the directivity. A coupled line compensation structure 12 is provided at the dielectric support bar 11 to improve this problem and enhance the directivity of the micro coaxial ultra-wideband bi-directional coupler; in order to compensate for the parasitic coupling brought by the dielectric support bar, starting from the rules of the coupled line size parameters and the odd and even mode impedances, the width of the inner conductor at the loading position of the dielectric support bar 11 can be reduced by a set size, and the odd and even mode impedances are corrected by changing the geometric size of the inner conductor. The specific coupled line compensation structure 12 is as Figure 4 shown. Since the coupled line compensation structure 12 restores the odd and even mode impedance characteristics of the coupled lines, the simulation result of the micro coaxial ultra-wideband bi-directional coupler maintains a directivity of 20 dB.

[0044] Please refer to Figure 5 , a front cross-sectional view of a micro coaxial ultra-wideband bi-directional coupler A based on a 1.0 mm coaxial connector package according to an embodiment of the present invention, which also shows the structural details of a narrow-side Y-junction 13. The narrow-side Y-junction 13 includes an outer conductor matching structure 16 and a tapered inner conductor structure 17. The distance between the inner conductors of the narrow-side Y-junction 13 is relatively small, and the internal matching structure of the outer conductor 7 at the narrow-side Y-junction 13 is very likely to affect the coupling degree, return loss, and directivity of the micro coaxial ultra-wideband bi-directional coupler. Therefore, at the narrow-side Y-junction 13, the outer conductor matching structure 16 is set as a three-layer stepped matching structure to balance the return loss and coupling degree performance, so that the micro coaxial ultra-wideband bi-directional coupler maintains a stable coupling degree and good return loss within the operating frequency band. The width of the inner conductor is relatively thin, which is not conducive to the size matching of the load port and the mechanical strength performance. Therefore, at the narrow-side Y-junction 13, the inner conductor gradually changes to a wider size to form a tapered inner conductor structure 17, and it presents an outer shape with two consecutive 45° twists, twisting the load port inside the chip topology of the micro coaxial ultra-wideband bi-directional coupler. Therefore, without occupying additional chip area, impedance matching with a circular load port is achieved, which is beneficial for realizing a compact structure package.

[0045] Please refer to Figure 6, An axonometric view of a micro coaxial ultra-wideband dual directional coupler A based on a 1.0 mm coaxial connector package provided by an embodiment of the present invention. When the model is simulated in the figure, equivalent 1.0 mm coaxial connectors 18 are added to the input port 1, output port 2, coupling port 3, isolation port 4, first load port 5, and second load port 6 respectively. The outer conductor inner diameter of the equivalent 1.0 mm coaxial connector 18 is 1 mm, the inner conductor diameter of the equivalent 1.0 mm coaxial connector 18 is 0.434 mm, and the length is 3 mm. At both ends of the micro coaxial ultra-wideband dual directional coupler, positioning pin holes 19 are extended and opened on the outer conductor 7 away from the ports. The positioning pin holes 19 are used to position the chip during packaging and integration.

[0046] The simulation results of the first type of micro coaxial ultra-wideband dual directional coupler A are as Figures 7 to 10 shown. In the broadband frequency range from DC to 120 GHz, the return loss of the input port 1 is higher than 20 dB, the coupling degree jitters between 10 and 12 dB, the insertion loss is less than 2.5 dB, and the directivity is higher than 20 dB. Therefore, the micro coaxial ultra-wideband dual directional coupler A can help improve the performance of the ultra-wideband vector network analyzer and promote the miniaturization of the vector network analyzer.

[0047] Please refer to Figure 11 , An axonometric view of the packaging structure of a micro coaxial ultra-wideband dual directional coupler A based on a 1 mm flange type connector package provided by an embodiment of the present invention; the packaging structure includes an upper cover plate 20 and a lower cover plate 21. The micro coaxial ultra-wideband dual directional coupler is fixed between the upper cover plate 20 and the lower cover plate 21 through the positioning pin holes 19 and the cover plate positioning pins 22. The upper cover plate 20 and the lower cover plate 21 are fastened by screws 23. The screws 23 pass through the through holes of the upper cover plate 20 and enter the threaded holes provided in the lower cover plate 21 for fastening. 1 mm flange type connectors are provided at the input port 1, output port 2, coupling port 3, isolation port 4, first load port 5, and second load port 6.

[0048] Please refer to Figure 12, is an exploded view of the packaging structure of a micro coaxial ultra-wideband dual-directional coupler A based on a 1mm flange-type connector packaging; a through hole is opened at the position corresponding to the load port on the upper cover plate 20, and the 1.0mm coaxial connector 24 in the vertical direction is assembled with the upper cover plate 20 through the positioning through hole and the screw 23 of the upper cover plate 20. After assembly, the coaxial end face of the 1.0mm coaxial connector 24 in the vertical direction is correspondingly connected to the two load ports of the micro coaxial ultra-wideband dual-directional coupler. The micro coaxial ultra-wideband dual-directional coupler is placed in the groove of the lower cover plate 21, and the depth of the groove is consistent with the thickness of the micro coaxial ultra-wideband dual-directional coupler. The 1.0mm coaxial connector 24 in the horizontal direction is connected to the upper cover plate 20 and the lower cover plate 21 respectively through the cover plate positioning pin 22 after the upper cover plate 20, the lower cover plate 21 and the micro coaxial ultra-wideband dual-directional coupler are assembled, positioned at the interface of the micro coaxial ultra-wideband dual-directional coupler, and fastened to the upper cover plate 20 and the lower cover plate 21 respectively through the screw 23.

[0049] Example 2, please refer to Figure 13 , is a schematic diagram of the eight-layer process used for a micro coaxial ultra-wideband dual-directional coupler B based on a 0.8mm coaxial connector packaging provided by an embodiment of the present invention. The micro coaxial ultra-wideband dual-directional coupler B is processed based on a standard eight-layer micro coaxial process, that is, the height of each layer h av = 100μm, and the height of the inner conductor h inner2 = 200μm. The design of the inner conductors of the micro coaxial ultra-wideband dual-directional coupler B and the micro coaxial ultra-wideband dual-directional coupler A is the same. The difference lies in the interconnection matching structure between the ports and the connectors and the height of the inner conductor. If the height of the inner conductor of the micro coaxial ultra-wideband dual-directional coupler B is the same as that of the micro coaxial ultra-wideband dual-directional coupler A, which is 240μm, then when the horizontal port is interconnected with the 0.8mm coaxial connector 26, since the inner conductor is eccentric with respect to the outer conductor 7, higher-order modes will be generated, resulting in spike resonance in its high-frequency performance, which is not conducive to the use of the micro coaxial ultra-wideband dual-directional coupler.

[0050] Please refer to Figure 14 , is a front detail view of a micro coaxial ultra-wideband dual-directional coupler B based on a 0.8mm coaxial connector packaging provided by an embodiment of the present invention; among them, it includes a rectangular coaxial interface in the horizontal direction and two circular coaxial interfaces in the vertical direction. The rectangular coaxial interface includes an input port 1, an output port 2, a coupling port 3, and an isolation port 4. The circular coaxial interfaces include a first load port 5 and a second load port 6; the impedance of the six ports is 50 ohms, which is used to connect the 0.8mm coaxial connector.

[0051] Please refer to Figure 15, An axonometric view of the micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by the embodiment; during simulation in the figure, equivalent 0.8mm coaxial connectors 25 are respectively set at the input port 1, output port 2, coupling port 3, isolation port 4, first load port 5 and second load port 6. The outer conductor inner diameter of the equivalent 0.8mm coaxial connector 25 is 0.8mm, the inner conductor diameter of the equivalent 0.8mm coaxial connector 25 is 0.374mm, and the length is 3mm. At both ends of the micro - coaxial ultra - wideband dual - directional coupler away from the ports, positioning pin holes 19 are extendedly opened on the outer conductor 7, and the positioning pin holes 19 are used to fix the position of the micro - coaxial ultra - wideband dual - directional coupler during packaging and integration.

[0052] Please refer to Figure 16 , An axonometric view of the packaging structure of the micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by the embodiment; the packaging structure includes an upper cover plate 20 and a lower cover plate 21. The micro - coaxial ultra - wideband dual - directional coupler B is fixed between the upper cover plate 20 and the lower cover plate 21 through the positioning pin holes 19 and the cover plate positioning pins 22, and the upper cover plate 20 and the lower cover plate 21 are fastened by screws 23. The screws 23 pass through the through - holes of the upper cover plate 20 and enter the threaded holes provided in the lower cover plate 21 for fastening.

[0053] Please refer to Figure 17 , An exploded view of the packaging structure of the micro - coaxial ultra - wideband dual - directional coupler B based on 0.8mm coaxial connector packaging provided by the embodiment; conventional 0.8mm coaxial connectors 26 are used both in the vertical direction and the horizontal direction. The 0.8mm coaxial connector 26 in the vertical direction is connected to the upper cover plate 20 through the positioning through - holes and fastening screws on the upper cover plate 20. After assembly, the coaxial end faces of the 0.8mm coaxial connector 26 in the vertical direction are correspondingly connected to the end faces of the two load ports of the micro - coaxial ultra - wideband dual - directional coupler. Through - holes are opened at the positions of the upper cover plate 20 corresponding to the load ports. The micro - coaxial ultra - wideband dual - directional coupler is placed in the groove of the lower cover plate 21, and the depth of the groove is consistent with the thickness of the micro - coaxial ultra - wideband dual - directional coupler. The connector in the horizontal direction is inserted into the semi - cylindrical groove integrally formed by the upper cover plate 20 and the lower cover plate 21 after the upper cover plate 20, the lower cover plate 21 and the micro - coaxial ultra - wideband dual - directional coupler are assembled, so as to be positioned at the ports of the micro - coaxial ultra - wideband dual - directional coupler, and is fixedly connected to the upper cover plate 20 and the lower cover plate 21 by screws 23. The screws 23 for fastening the 0.8mm coaxial connector 26 in the packaging structure all pass through the connection holes on the 0.8mm coaxial connector 26 and are respectively inserted into the threaded holes of the upper cover plate 20 and the lower cover plate 21 for fastening.

[0054] The simulation results of the micro - coaxial dual - directional coupler B based on 0.8mm coaxial connector packaging are as Figure 18 , Figure 19 ,Figure 20 and Figure 21 As shown, in the broadband frequency range from DC to 150 GHz, the return loss of input port 1 is higher than 14 dB, the coupling degree jitter is between 10 dB and 12 dB, the insertion loss is less than 3 dB, and the directivity is higher than 18 dB. Therefore, the micro coaxial dual directional coupler B based on the 0.8 mm coaxial connector 26 package can improve the performance of the ultra-wideband vector network analyzer and facilitate its application in cutting-edge fields such as 6G communication and quantum measurement and control.

[0055] The above is the description of a micro coaxial chip interconnection structure based on a connector and a connector-like structure provided by the present invention. For those skilled in the art, according to the idea of the embodiments of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A micro coaxial dual directional coupler with ultra-wideband performance, characterized in that, It includes two ultra-wideband micro-coaxial single directional couplers. Among them, the micro-coaxial coupling line of the ultra-wideband micro-coaxial single directional coupler is a multi-section tapered coupling line with continuously varying impedance; the first ends of the two single directional couplers are both provided with narrow-side Y-junctions (13), and the second ends of the two single directional couplers are respectively provided with wide-side Y-junctions (14). The two coaxial ports at the first ends of the two single directional couplers are cascaded through the narrow-side Y-junction (13), and the other two coaxial ports are used as load ports; the spacing and cross-section of the micro-coaxial coupling line at the first end are smaller than those of the micro-coaxial coupling line at the second end. The four coaxial ports at the second ends of the two single directional couplers serve as the input port (1), output port (2), coupling port (3), and isolation port (4) of the bi-directional coupler; the axis of the load port is perpendicular to the plane where the axes of the four coaxial ports at the second end are located.

2. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 1, characterized in that, It includes an inner conductor, an outer conductor (7), and a dielectric support bar (11). The load port includes a first load port (5) and a second load port (6); the outer conductor (7) is hollow, and the inner conductor is suspended in the outer conductor (7) through a plurality of axially arranged dielectric support bars (11); the inner conductor includes a first micro-coaxial coupling line (8), a second micro-coaxial coupling line (9), a third micro-coaxial coupling line (10), and a Y-junction. The input port (1), the first micro-coaxial coupling line (8), the output port (2), the coupling port (3), the second micro-coaxial coupling line (9), and the second load port (6) form a single directional coupler; the input port (1), the first micro-coaxial coupling line (8), the output port (2), the isolation port (4), the third micro-coaxial coupling line (10), and the first load port (5) form a single directional coupler. The input port (1) and the output port (2) are located on the first micro-coaxial coupling line (8), the coupling port (3) and the second load port (6) are located on the second micro-coaxial coupling line (9), and the isolation port (4) and the first load port (5) are located on the third micro-coaxial coupling line (10).

3. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 2, wherein The first ends of the two single directional couplers are bent into a C shape and nested with each other; one port of the narrow-side Y-junction (13) is connected through a cascaded transition coaxial line (15), and the first micro-coaxial coupling line (8) serving as the main path transmission line becomes an integral body. The included angle between two adjacent ports of the wide-side Y-junction (14) is 90°.

4. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 1, characterized in that, The input port (1), output port (2), coupling port (3), isolation port (4), and the two load ports are provided with 1.0 mm coaxial connectors or 0.8 mm coaxial connectors. The ultra-wideband micro-coaxial single directional coupler is formed based on the metal additive manufacturing process and is formed by an eight-layer process. The thickness of the dielectric support bar (11) is 0.04 mm.

5. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 4, wherein When setting a 1mm coaxial connector, the forming height of the fifth layer h sp Increase the set value, the height of the inner conductor h inner1 Correspondingly increase the same value as the set value; at the position of the narrow-side Y-junction (13), the outer conductor matching structure (16) is set as a three-layer stepped matching structure, and the inner conductor gradually changes to a wider size to form a tapered inner conductor structure (17).

6. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 4, characterized in that, When setting up a 0.8 mm coaxial connector, the height of each layer h av is 100 μm; the height of the micro coaxial coupling line h inner2 is 0.2 mm.

7. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 1, characterized in that, A coupling line compensation structure (12) is formed by reducing the width of the inner conductor at the dielectric support bar (11).

8. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 1, characterized in that The input port (1), output port (2), coupling port (3), and isolation port (4) are all provided with GSG interfaces.

9. The micro coaxial dual directional coupler with ultra-wideband performance according to claim 1, characterized in that, The load port adopts a micro-coaxial built-in integrated load.

10. A micro coaxial dual-directional coupler packaging structure, characterized in that, It includes an upper cover plate (20) and a lower cover plate (21). There is a groove between the upper cover plate (20) and the lower cover plate (21), and the groove is used to accommodate the micro coaxial dual directional coupler as described in any one of claims 1-9. The planar shape of the groove is consistent with the planar projection of the micro coaxial dual directional coupler; the depth of the groove is consistent with the thickness of the micro coaxial dual directional coupler.

11. The micro coaxial dual-directional coupler packaging structure according to claim 10, characterized in that, Coaxial connectors are arranged at positions corresponding to the ports of the micro coaxial dual directional coupler on the upper cover plate (20) through side plates. The side plates are fixedly connected to the upper cover plate (20) and the lower cover plate (21), and through holes are opened at positions corresponding to the load ports on the upper cover plate (20).

12. The micro coaxial dual-directional coupler packaging structure according to claim 10, characterized in that, Semicylindrical grooves are opened at positions corresponding to the horizontal direction ports of the micro coaxial dual directional coupler on the upper cover plate (20) and the lower cover plate (21), and through holes are opened at positions corresponding to the load ports on the upper cover plate (20).

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