Omega-shaped micro coaxial chip structure and radio frequency test calibration system and method

Abstract

The invention discloses an ultra-wideband coaxial interconnection structure, belongs to the technical field of microwave radio frequency, and solves the problems of complicated installation, misplug risk and limited high-frequency performance caused by special-shaped pairing of traditional interfaces. The method is characterized in that an omega-like rectangular coaxial transmission line is combined with an SU-8 photoresist medium support to realize high-efficiency connection of circular / rectangular coaxial and waveguide without male and female distinguishing. The middle elastic buffer area of the omega-like structure can absorb the deformation of the inner conductor during plugging, thereby improving the mechanical stability and durability. Cavity structures are arranged at the two ends of the interface to suppress parasitic coupling, the protruding design of the inner conductor enhances electric contact, and high-band impedance matching and signal integrity are guaranteed. The structure supports multi-form interconnection, shows excellent radio frequency performance in actual measurement from DC to 110GHz, has the theoretical upper limit of 300GHz, is adaptive to various interfaces, and has the advantages of low loss and simple assembly. The method is particularly suitable for high-frequency testing and packaging scenes, provides a reliable and low-loss system solution for ultra-wideband heterogeneous interconnection, remarkably reduces the operation complexity and improves the system reliability.

Description

Technical Field

[0001] The present invention belongs to the field of microwave radio frequency testing technology, and in particular relates to an Ω-shaped micro-coaxial chip structure, a radio frequency testing calibration system and a method. Background Art

[0002] In recent years, with the rapid development of millimeter-wave communications, satellite payload testing, and high-frequency integrated circuits, the demand for multi-modal interface compatibility and operational convenience in RF testing and calibration has become increasingly prominent. Traditional calibration methods primarily rely on circular coaxial-to-circular coaxial interface matching, but this is limited by the following issues: First, the same-shape and opposite-sex pairing rules, such as circular coaxial-to-circular coaxial and male-to-female matching, cannot directly support cross-shape connections, such as connecting circular coaxial to rectangular coaxial. This makes the calibration process cumbersome and has low fault tolerance. First, during operation, it is necessary to ensure that the male and female connectors of the device under test and the test instrument accurately match. If the same-sex male-male or female-female connectors are misused, physical connection failure or even physical damage to the interface will occur. Second, to meet the pairing requirements of different scenarios, the test system must be equipped with a large number of transition cables and adapters, significantly increasing equipment cost and calibration preparation time. In addition, frequent plugging and unplugging causes wear on the contact end faces, degrading impedance consistency and introducing additional calibration errors. Second, there is a bottleneck in high-frequency performance. Due to the exacerbated skin effect and mechanical processing limitations, the operating frequency upper limit of conventional circular coaxial cables is difficult to exceed 220GHz, requiring a 0.6mm connector. The insertion loss in the high-frequency band increases sharply, the cost is high, and it has not yet been maturely applied.

[0003] In contrast, rectangular coaxial cables, with their distributed electromagnetic field structure and lower-loss transmission mode, have a theoretical operating frequency of over 300 GHz and can maintain excellent signal integrity even at high frequencies, providing a potential technical path for next-generation terahertz communication testing. These issues collectively expose the limitations of traditional solutions in terms of efficiency, reliability, compatibility, and frequency band scalability. Therefore, a calibration solution that is compatible with heterogeneous interfaces, such as circular and rectangular coaxial cables, and simplifies connection operations is urgently needed to improve test efficiency, reduce the risk of human error, and unleash the potential of high-frequency testing. Summary of the Invention

[0004] In order to solve the above problems and achieve the above objectives, the present invention provides an Ω-shaped micro-coaxial chip structure, a radio frequency test and calibration system and method, which can realize the interconnection of rectangular coaxial and rectangular coaxial, the interconnection of rectangular coaxial and circular coaxial, and the conversion of rectangular coaxial to waveguide, and can also realize the calibration between rectangular coaxial.

[0005] In order to achieve the above-mentioned objectives, in a first aspect, the present invention provides an Ω-shaped micro-coaxial chip structure, comprising a first rectangular coaxial interface, a first horizontal rectangular coaxial line, a curved rectangular coaxial line, a second horizontal rectangular coaxial line, and a second rectangular coaxial interface connected in sequence, wherein the first horizontal rectangular coaxial line, the curved rectangular coaxial line, and the second horizontal rectangular coaxial line are inner conductors, and the inner conductors are suspended in the outer conductor through a dielectric support structure, the outer conductor of the first rectangular coaxial interface is concave inward to a set depth to form a cavity structure, and the inner conductor at the second rectangular coaxial interface protrudes relative to the outer conductor by a set length to form a protruding structure; the first horizontal rectangular coaxial line, the second horizontal rectangular coaxial line, and the curved rectangular coaxial line are all connected with arc-shaped inner conductors with the same cross-section for smooth transition.

[0006] Furthermore, a plurality of dielectric support structures are evenly arranged near the two ports, one is provided in the middle section of the curved rectangular coaxial line, and the dielectric support structure is made of SU-8 photoresist.

[0007] Furthermore, a positioning hole is provided on the outer conductor.

[0008] Furthermore, the curvature of the curved rectangular coaxial line does not exceed half a circular arc.

[0009] In a second aspect, the present invention provides an ultra-wideband coaxial interconnection structure, comprising at least one of the above-mentioned Ω-shaped micro-coaxial chip structures; a first rectangular coaxial interface is interconnected with a circular coaxial interface, and is connected to a rectangular coaxial interface of an external device through a second rectangular coaxial interface.

[0010] Furthermore, the second rectangular coaxial interface is directly connected to the waveguide interface.

[0011] In a third aspect, the present invention also provides a radio frequency test and calibration system for an ultra-wideband coaxial interconnection structure, wherein the second rectangular coaxial interfaces of two Ω-shaped micro-coaxial chip structures are directly connected, and the two first rectangular coaxial interfaces are respectively connected to standard circular coaxial connectors; or the first rectangular coaxial interface is connected to the standard circular coaxial connector, and the second rectangular coaxial interface is an air open circuit structure or a short-circuit plate structure is set; or the second rectangular coaxial interfaces of two Ω-shaped micro-coaxial chip structures are connected through a rectangular coaxial line, and the two first rectangular coaxial interfaces are respectively connected to standard circular coaxial connectors, or the first rectangular coaxial interface is connected to the standard circular coaxial connector, and the second rectangular coaxial interface is connected to a patch load structure.

[0012] In a fourth aspect, the present invention provides a radio frequency test and calibration method for an ultra-wideband coaxial interconnection structure. Based on the TRL calibration method, through-calibration is achieved by directly connecting the second rectangular coaxial interfaces of two Ω-shaped micro-coaxial chip structures, and the two first rectangular coaxial interfaces are respectively connected to standard circular coaxial connectors; reflection calibration is achieved by connecting the first rectangular coaxial interface to the standard circular coaxial connector, and the second rectangular coaxial interface is an air open circuit structure or a short-circuit plate structure; line calibration is achieved by connecting the second rectangular coaxial interfaces of two Ω-shaped micro-coaxial chip structures through a rectangular coaxial line, and the two first rectangular coaxial interfaces are respectively connected to standard circular coaxial connectors, and micro-coaxial transmission line structures of different lengths are used during the calibration process.

[0013] Furthermore, based on the SOLT calibration method, the through calibration is achieved by directly connecting two second rectangular coaxial interfaces of the Ω-shaped micro-coaxial chip structure, and the two first rectangular coaxial interfaces are respectively connected to the standard circular coaxial connectors; the open circuit calibration is achieved by connecting the first rectangular coaxial interface to the standard circular coaxial connector, and the second rectangular coaxial interface is an air open circuit structure; the short circuit calibration is achieved by connecting the first rectangular coaxial interface to the standard circular coaxial connector, and the second rectangular coaxial interface is a short circuit piece structure; the load calibration is achieved by connecting the first rectangular coaxial interface to the standard circular coaxial connector, and the second rectangular coaxial interface is a patch load structure.

[0014] The ultra-wideband coaxial interconnect structure radio frequency test calibration method of the present invention can also be used for DC to 67 GHz, DC to 110 GHz, DC to 145 GHz, and DC to 220 GHz ultra-wideband radio frequency tests.

[0015] Compared with existing technologies, the present invention has at least the following advantages: It provides a method and application structure for interconnecting and calibrating circular coaxial and rectangular coaxial cables. Through an Ω-shaped micro-coaxial chip structure, seamless mechanical coupling and impedance matching between circular and rectangular coaxial ends are achieved without the need for additional adapters. The need to distinguish between male and female connectors is eliminated, allowing direct connection of any interface, significantly simplifying the operation process and avoiding the risk of mismatching. The Ω-shaped curved portion provides redundant deformation space when the inner conductor is subjected to stress, preventing plastic deformation and fracture during insertion and removal, and ensuring long-term reliability. Simulation results show that when two Ω-shaped micro-coaxial chip structures are connected back-to-back and connected to two 1.0mm connectors, they exhibit excellent RF performance from DC to 110 GHz. Theoretically, the operating frequency can reach up to 300 GHz, providing a systematic solution for cross-modality RF calibration that combines high compatibility, high reliability, and high-frequency scalability.

[0016] Furthermore, the present invention provides an Ω-shaped micro-coaxial chip structure comprising an Ω-shaped rectangular coaxial transmission line and a dielectric support structure. The Ω-shaped rectangular coaxial transmission line comprises two horizontal rectangular coaxial interfaces with a curved rectangular coaxial line section in between. The first horizontal rectangular coaxial interface connects to the circular coaxial transmission line, while the second horizontal rectangular coaxial interface connects to a rectangular coaxial interface on another device, thereby enabling circular-to-rectangular coaxial interconnection and calibration. This structure also enables efficient, low-loss, ultra-wideband signal interconnection and conversion from the circular coaxial interface to the rectangular coaxial interface, making it suitable for complex system integration.

[0017] Furthermore, in the Ω-shaped rectangular coaxial transmission line, one end connected to the circular coaxial transmission line has a cavity structure for reducing parasitic coupling. The outer conductor is removed along the rectangular cross-section near the port on the top and bottom layers of the outer conductor to form a cavity structure, and the cavity structure is simple.

[0018] Furthermore, in the Ω-shaped rectangular coaxial transmission line, the inner conductor at one end connected to the rectangular coaxial transmission line protrudes 20 microns from the outer conductor, so that a sufficiently tight connection can be achieved when devices are connected to each other.

[0019] Furthermore, in the Ω-shaped rectangular coaxial transmission line, the SU-8 photoresist support structure is evenly arranged on the transmission line near the two ports; in the Ω-shaped rectangular coaxial transmission line, the single support at the center of the curved section ensures the stability of the inner conductor while minimizing the amount of dielectric to reduce loss. The deformation of the inner conductor can be controlled in the curved area, and multiple support points near the ports enhance the mechanical stability of the structure.

[0020] Furthermore, the positioning holes are provided on the outer conductor to facilitate positioning, installation and packaging of the coaxial interconnect structure and improve the stability of the packaging.

[0021] Furthermore, the curvature of the bent rectangular coaxial line does not exceed half a circular arc, minimizing the additional phase shift and loss introduced by the bend, making the arc-shaped smooth transition design more effective, maintaining impedance continuity, and helping to achieve the best balance between structural compactness and electrical performance while meeting the turning requirements.

[0022] Furthermore, the smoothly transitioned arc-shaped inner conductor significantly reduces signal reflection and loss at the bend, ensuring broadband transmission performance.

[0023] Furthermore, through the protruding structure design, the rectangular coaxial output interface of the chip can be directly and efficiently connected to the waveguide interface, and the second rectangular coaxial interface is directly connected to the waveguide interface, eliminating the need for additional converters, simplifying the system structure, and reducing insertion loss. It is particularly suitable for high-frequency waveguide system integration, and can realize the interconnection of rectangular waveguide and rectangular coaxial, rectangular waveguide and circular coaxial, and can realize the frequency band conversion functions of 0.6mm coaxial to WR-5 rectangular waveguide, 0.6mm coaxial to WR-6 rectangular waveguide, 0.8mm coaxial to WR-8 rectangular waveguide, and 1.0mm coaxial to WR-10 rectangular waveguide.

[0024] The present invention provides a radio frequency test and calibration system for an ultra-wideband coaxial interconnect structure. Based on a combination of standardized calibration parts for the coaxial interconnect structure, the system covers all types of calibration standard parts requirements through different connection forms (direct connection, open circuit, short circuit, delay line, load), allowing the single-chip structure to be reused as a multi-purpose calibration tool, significantly simplifying the construction of the ultra-wideband test system.

[0025] Furthermore, the Ω-shaped micro-coaxial chip structure naturally implements the core elements of TRL calibration: direct connections correspond to through-holes, open / short terminations correspond to reflections, and simplified transmission lines correspond to delay lines. This allows high-precision TRL calibration at the chip level without the need for complex adapters, making it particularly suitable for high-frequency, broadband testing.

[0026] Furthermore, the Ω-shaped micro-coaxial chip structure can be flexibly configured as the elements required for SOLT calibration: direct connection realizes direct connection, air open circuit realizes open circuit, short-circuit plate realizes short circuit, and load structure realizes load. A single platform can provide a full set of SOLT calibration, greatly improving test efficiency and consistency.

[0027] Furthermore, the RF test and calibration method of the ultra-wideband coaxial interconnect structure described in this application can cover the extreme wideband testing requirements from DC to terahertz frequency bands, highlighting the key application value of the structure and calibration method in the millimeter wave / terahertz field, and meeting the testing challenges of cutting-edge high-frequency systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To more clearly illustrate the embodiments of the present invention or the prior art solutions, the following briefly introduces the drawings used in the embodiments or the prior art solutions. It should be noted that the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0029] Figure 1 An oblique axonometric diagram of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 2A horizontal cross-sectional view of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 3 A front view of a detailed diagram of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 4 A schematic diagram of the interconnection between an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process and a device with a coaxial external interface provided by an embodiment of the present invention; Figure 5 A schematic diagram of a rectangular coaxial through-calibration structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 6 A schematic diagram of a rectangular coaxial open-circuit calibration structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 7 A schematic diagram of a rectangular coaxial short-circuit calibration structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 8 A schematic diagram of a rectangular coaxial line alignment structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 9 A schematic diagram of a rectangular coaxial load calibration structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; Figure 10 A diagram showing simulation results of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention; In the accompanying drawings, 1. First rectangular coaxial interface; 2. Second rectangular coaxial interface; 3. First horizontal rectangular coaxial line; 4. Bent rectangular coaxial line; 5. Second horizontal rectangular coaxial line; 6. Positioning hole; 7. Standard circular coaxial connector; 8. Standard rectangular coaxial connector; 9. Air open circuit structure; 10. Short-circuit plate structure; 11. Rectangular coaxial line; 12. Cavity structure; 13. Protrusion structure; 14. Dielectric support structure; 15. Patch load structure. DETAILED DESCRIPTION

[0030] In order to make the objects, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be noted that the described embodiments are only part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0031] In the description of the embodiments of the present invention, it should be understood that the terms "horizontal", "horizontal direction", "top", "bottom", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and cannot be considered as indicating that the elements or devices indicated are in a specific orientation.

[0032] The present invention proposes an ultra-wideband coaxial interconnection structure that is not male or female, which can realize the conversion of rectangular coaxial-rectangular coaxial, rectangular coaxial-circular coaxial and rectangular coaxial-waveguide. The ultra-wideband coaxial interconnection structure includes an Ω-shaped micro-coaxial chip structure, an interface connected to the circular coaxial, an interface connected to the rectangular coaxial and a dielectric support structure 14. Based on the Ω-shaped micro-coaxial chip structure, the deformation of the inner conductor in the Ω-shaped micro-coaxial chip structure can be controlled in the bending part. After the interface on the Ω-shaped micro-coaxial chip structure comes into close contact with other devices, since the middle section of the coaxial line is in the Ω-shape, the stress and deformation will be limited to the bending part, and the stress and deformation at the interface are very small, which can effectively protect the inner conductor and improve reliability and service life.

[0033] The interfaces of rectangular coaxial-rectangular coaxial, rectangular coaxial-circular coaxial, and rectangular coaxial-waveguide conversions all utilize an equivalent connector, namely a circular coaxial transmission line structure or a rectangular coaxial transmission line structure, for excitation. The impedance matching of the discontinuities is performed using the inner and outer conductor designs of an Ω-shaped micro-coaxial chip structure, thereby enabling effective conversion between the micro-coaxial line and the standard coaxial connector.

[0034] In the description of the embodiments of the present invention, the structural dimensions given are preferred parameters. With reference to the embodiments of the present invention, the dimensional parameters of each component may be modified to further obtain the actual required performance.

[0035] In embodiment 1, the present invention provides an Ω-shaped micro-coaxial chip interconnection structure, comprising an Ω-shaped rectangular coaxial transmission line and a dielectric support structure 14, wherein the Ω-shaped rectangular coaxial transmission line comprises a first rectangular coaxial interface 1, a first horizontal rectangular coaxial line 3, a curved rectangular coaxial line 4, a second horizontal rectangular coaxial line 5, and a second rectangular coaxial interface 2 connected in sequence, wherein the outer sides of the first horizontal rectangular coaxial line 3, the curved rectangular coaxial line 4, and the second horizontal rectangular coaxial line 5 are outer conductors; the connection between the first horizontal rectangular coaxial line 3, the second horizontal rectangular coaxial line 5, and the curved rectangular coaxial line 4 is formed by a A circular arc inner conductor of the same cross-section is used for transition. The outer conductor of the first horizontal rectangular coaxial line 3 at the first rectangular coaxial interface 1 is provided with a cavity structure 12 for reducing parasitic coupling. The cavity structure 12 is formed by the outer conductor at the first rectangular coaxial interface 1 being recessed inward by a set distance. A protruding structure 13 is provided on the inner conductor at the second rectangular coaxial interface 2. The protruding structure 13 is formed by the inner conductor protruding by a set distance relative to the outer conductor. The dielectric support structure 14 includes uniformly arranged SU-8 photoresist support structures near the two ports and a single SU-8 photoresist support structure in the middle of the curved rectangular coaxial line 4. At the first rectangular coaxial interface 1, the outer conductor is removed along the rectangular cross-section near the port on the top and bottom layers of the outer conductor to form a cavity structure 12, thereby reducing parasitic coupling; at the second rectangular coaxial interface 2, the inner conductor protrudes by a set length compared to the outer conductor to form a protruding structure 13, thereby ensuring closer contact between the outer rectangular coaxial interface and the second rectangular coaxial interface 2; the SU-8 photoresist support structure in the dielectric support structure 14 is evenly arranged on the transmission line near the two ports to enhance structural stability; only one dielectric support structure 14 is set in the middle of the entire curved rectangular coaxial line 4, so that the deformation of the inner conductor is controlled to occur mainly in the bending area, so as to absorb the deformation, extend the service life of the overall structure and improve reliability.

[0036] In a second embodiment, the present invention provides a calibration method for rectangular coaxial structures, including TRL calibration, multi-line TRL calibration, and SOLT calibration. TRL calibration includes through-calibration in which an Ω-shaped micro-coaxial chip is directly connected via a first rectangular coaxial interface 1, reflection calibration performed via a simplified open-air structure 9 or a simplified short-circuit plate structure 10, and line calibration performed via a rectangular coaxial line 11. Multi-line TRL calibration includes line calibration performed via rectangular coaxial lines 11 of various lengths, including TRL calibration. SOLT calibration includes open-circuit calibration via a simplified open-air structure 9, short-circuit calibration via a simplified short-circuit plate structure 10, load calibration via a patch load structure 15, and through-calibration in which an Ω-shaped micro-coaxial chip is directly connected via the first rectangular coaxial interface 1.

[0037] See also Figure 1, an oblique axonometric diagram of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention, Figure 2 A horizontal cross-sectional view of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention. Figure 3 A front detail view of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided in an embodiment of the present invention includes a first rectangular coaxial interface 1, a second rectangular coaxial interface 2, a first horizontal rectangular coaxial line 3, a curved rectangular coaxial line 4, a second horizontal rectangular coaxial line 5, and a positioning hole 6 for positioning the chip and the fixture. The first horizontal rectangular coaxial line 3, the curved rectangular coaxial line 4, and the second horizontal rectangular coaxial line 5 are supported by a dielectric support structure 14. The first horizontal rectangular coaxial line 3, the second horizontal rectangular coaxial line 5, and the curved rectangular coaxial line 4 are connected by a circular arc inner conductor with the same cross-section for transition. The impedance of the first rectangular coaxial interface 1 and the second rectangular coaxial interface 2 is 50 ohms, and they are used to connect the standard circular coaxial connector 7 and the standard rectangular coaxial connector 8 respectively; wherein at the first rectangular coaxial interface 1, the outer conductor of the top and bottom layers of the outer conductor near the port is removed along the rectangular cross section to form a cavity structure 12, thereby reducing parasitic coupling; at the second rectangular coaxial interface 2, the inner conductor protrudes 20 microns relative to the outer conductor to form a protruding structure 13, the purpose of which is to ensure a closer contact between the external rectangular coaxial interface and the second rectangular coaxial interface 2. At the same time, since there is no dielectric support structure 14 on the bent portion of the bent rectangular coaxial line 4, the inward deformation of the protruding structure 13 will be transmitted to the bent portion of the bent rectangular coaxial line 4, and the bent portion absorbs the deformation, thereby ensuring the service life of the protruding structure 13, the first horizontal rectangular coaxial line 3 and the second horizontal rectangular coaxial line 5, thereby increasing the service life of the entire structure. A positioning hole 6 is provided on the outer conductor. The positioning hole 6 is provided on both sides above the ultra-wideband coaxial interconnection structure that does not distinguish between male and female. The position of the positioning hole 6 is referenced. Figure 3 .

[0038] See also Figure 4 , a schematic diagram of the interconnection between an ultra-wideband coaxial interconnection structure based on a copper-based additive manufacturing process and a device with a coaxial external interface provided by an embodiment of the present invention, wherein a circular coaxial line is used as a simplified standard circular coaxial connector 7, and the external device is connected to the first rectangular coaxial interface 1 through the standard circular coaxial connector 7, and a rectangular coaxial line 11 is used as a simplified standard rectangular coaxial connector 8, and the external device is connected to the second rectangular coaxial interface 2 through the standard rectangular coaxial connector 8.

[0039] A waveguide probe is set on the inner conductor end face of the second rectangular coaxial interface 2, and then the second rectangular coaxial interface 2 is directly connected to the waveguide interface.

[0040] See also Figure 5, a schematic diagram of a rectangular coaxial straight-through calibration structure of an ultra-wideband coaxial interconnection structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention includes a simplified standard circular coaxial connector 7 and a pair of directly connected Ω-shaped micro-coaxial chips, wherein the second rectangular coaxial interfaces 2 of the two Ω-shaped micro-coaxial chip interconnection structures are connected, and the two first rectangular coaxial interfaces 1 are located at both ends of the rectangular coaxial straight-through calibration structure, and the first rectangular coaxial interfaces 1 are connected to the standard circular coaxial connector 7.

[0041] See also Figure 6 , a schematic diagram of a rectangular coaxial open-circuit calibration structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention includes a simplified standard circular coaxial connector 7, a simplified air open-circuit structure 9, and a single Ω-shaped micro-coaxial chip, wherein a first rectangular coaxial interface 1 is connected to the standard circular coaxial connector 7, and an air open-circuit structure 9 is provided at the second rectangular coaxial interface 2; as an example, the air open-circuit structure 9 adopts a standard reflector and is located at the end of the second rectangular coaxial interface 2. The air gap between the inner conductor and the outer conductor realizes an ideal open-circuit boundary condition, which can provide a stable reflection signal within the ultra-wide frequency band and be used as an open-circuit standard in TRL calibration. It has the characteristics of simple structure, excellent reflection performance, and compatibility with micro-coaxial chips.

[0042] See also Figure 7 , a schematic diagram of a rectangular coaxial short-circuit calibration structure of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention includes a simplified standard circular coaxial connector 7, a simplified short-circuit plate structure 10, and a single Ω-shaped micro-coaxial chip, wherein the first rectangular coaxial interface 1 is connected to the standard circular coaxial connector 7, and the short-circuit plate structure 10 is provided at the second rectangular coaxial interface 2. As an example, the short-circuit plate structure 10 is a simplified short-circuit standard part, located at the end of the second rectangular coaxial interface 2. The short-circuit plate structure 10 is a metal plate, which simultaneously connects the inner conductor and the outer conductor; by setting an ideal metal short-circuit boundary condition, the total reflection state is simulated. It is used to provide a short-circuit reference in TRL calibration, has a simple structure, stable reflection phase, and is suitable for ultra-wideband modeling and performance extraction.

[0043] See also Figure 8 , a schematic diagram of a calibration structure of a rectangular coaxial line 11 of an ultra-wideband coaxial interconnection structure provided by an embodiment of the present invention includes a simplified standard circular coaxial connector 7, a simplified rectangular coaxial line 11, and a pair of Ω-shaped micro-coaxial chips interconnected by the simplified rectangular coaxial line 11; the two ends of the simplified rectangular coaxial line 11 are connected to the second rectangular coaxial interface 2, and the two first rectangular coaxial interfaces 1 are respectively connected to the standard circular coaxial connector 7.

[0044] See also Figure 9A schematic diagram of a rectangular coaxial load calibration structure for an ultra-wideband coaxial interconnect structure provided by an embodiment of the present invention includes a simplified standard circular coaxial connector 7, a patch load structure 15, and a single Ω-shaped micro-coaxial chip structure, wherein a first rectangular coaxial interface 1 is connected to the standard circular coaxial connector 7, and a second rectangular coaxial interface 2 is connected to the patch load structure 15. As an example, the connection between the second rectangular coaxial interface 2 and the patch load structure 15 can be implemented using a micro-coaxial load structure with ultra-wideband performance, including a micro-coaxial packaging structure and a quartz substrate. The quartz substrate is disposed on the micro-coaxial packaging structure in an inverted manner, and the quartz substrate is electrically connected to the micro-coaxial packaging structure. The quartz substrate includes a quartz plate, a thin-film resistor, and a metal pad. The thin-film resistor and the metal pad are disposed on the surface of the quartz plate, the thin-film resistor is located between the metal pads, and the metal pad is used to connect to the micro-coaxial packaging structure. Three metal pads are provided, the middle metal pad is electrically connected to the inner conductor, and the metal pads on both sides are electrically connected to the outer conductor.

[0045] See also Figure 10 , a simulation result diagram of an ultra-wideband coaxial interconnect structure based on a copper-based additive manufacturing process provided by an embodiment of the present invention shows that the echo is less than -15dB in the DC to 110GHz frequency band, which can achieve seamless mechanical coupling and impedance matching between circular coaxial interfaces (such as 1.0mm connectors) and rectangular coaxial interfaces, and eliminate the need to distinguish between male and female heads, with little impact on test accuracy.

[0046] The present invention provides an ultra-wideband coaxial interconnect structure that solves the problems of complex operation, high risk of misinsertion, and limited high-frequency performance caused by the requirement for opposite-sex interface pairing in traditional coaxial connections. Based on an Ω-shaped micro-coaxial chip structure design and in conjunction with a dielectric support structure 14, it can achieve efficient connections between circular coaxial and rectangular coaxial, between rectangular coaxial, and between rectangular coaxial and waveguide, without relying on male and female interfaces. The middle section of the Ω-shaped micro-coaxial chip structure provides an elastic buffer area with the help of the curved rectangular coaxial line 4, which can effectively absorb the deformation of the inner conductor during insertion and removal, thereby significantly improving the mechanical stability and repeated service life of the connector. The dielectric support structure 14 is evenly arranged on the transmission line near the two ports. For the curved rectangular coaxial line 4, the dielectric support structure 14 is only provided in the middle, controlling the deformation of the inner conductor to the curved area. Increasing the thickness of the dielectric support structure 14 can improve the mechanical strength of the micro-coaxial chip during interconnection. The ultra-wideband coaxial interconnect structure of the present invention is applicable to operating frequency bands covering DC to 67 GHz, DC to 110 GHz, DC to 145 GHz, and DC to 220 GHz.

[0047] The calibration methods used in the present invention include TRL, multi-line TRL and SOLT calibration methods. The calibration parts used are standard rectangular coaxial calibration parts, including rectangular coaxial short-circuit calibration parts, rectangular coaxial line calibration parts and rectangular coaxial load calibration parts. The purpose is to adapt to the connection characteristics of the ultra-wideband coaxial interconnection structure proposed in the present invention. The rectangular coaxial short-circuit calibration part, namely the short-circuit plate structure 10, is used to provide an ideal short-circuit reference. The design ensures good conductivity and structural stability to reduce the influence of parasitic capacitance; the rectangular coaxial line calibration part, namely the rectangular coaxial line 11, is used for the transmission line standard in the TRL and multi-line TRL calibration methods. Its length and impedance strictly match the target frequency band to ensure calibration accuracy; the rectangular coaxial load calibration part, namely the patch load structure 15, is used to provide a good matching load to ensure the stability of the reference impedance of the measurement system and reduce the reflection coefficient as much as possible to optimize the calibration accuracy. This structure has strong compatibility, flexible connection, and convenient assembly. It is suitable for a variety of high-frequency testing and packaging scenarios. It has excellent RF performance in the DC to 110GHz frequency band, and the theoretical upper limit of the operating frequency can reach 300GHz, providing a high-reliability, low-loss, and easy-to-operate systematic solution for realizing ultra-wideband heterogeneous interface interconnection. The ultra-wideband coaxial interconnection structure described in this application can be used to realize circular coaxial-rectangular coaxial interconnection and calibration in the DC to 67GHz, DC to 110GHz, DC to 145GHz, and DC to 220GHz bands, overcoming the problem that the existing structure cannot directly support cross-morphological connections (such as circular coaxial and rectangular coaxial) and has a high-frequency performance bottleneck. It can be compatible with special-shaped interfaces (such as circular coaxial and rectangular coaxial) and simplify the calibration scheme of the connection operation to improve test efficiency, reduce the risk of human operation errors, and release the potential of high-frequency testing.

[0048] The above is a description of the Ω-shaped micro-coaxial chip structure, RF test and calibration system, and method provided by the present invention. Those skilled in the art will appreciate that variations in the specific implementation and scope of application are possible based on the principles of the present invention. In summary, this description should not be construed as limiting the present invention.

Claims

1. A micro-coaxial chip structure of a similar Ω shape, characterized in that: The invention comprises a first rectangular coaxial interface (1), a first horizontal rectangular coaxial line (3), a curved rectangular coaxial line (4), a second horizontal rectangular coaxial line (5) and a second rectangular coaxial interface (2) which are connected in sequence. The first horizontal rectangular coaxial line (3), the curved rectangular coaxial line (4) and the second horizontal rectangular coaxial line (5) are inner conductors. The inner conductors are suspended in the outer conductor through a dielectric support structure (14). The outer conductor of the first rectangular coaxial interface (1) is concave inward to a set depth to form a cavity structure (12). The inner conductor at the second rectangular coaxial interface (2) protrudes relative to the outer conductor by a set length to form a protruding structure (13). The first horizontal rectangular coaxial line (3) and the second horizontal rectangular coaxial line (5) are connected to the curved rectangular coaxial line (4) with arc-shaped inner conductors of the same cross-section for smooth transition.

2. The Ω-shaped micro-coaxial chip structure according to claim 1, characterized in that: A plurality of dielectric support structures (14) are evenly arranged near the two ports, and one is provided in the middle section of the curved rectangular coaxial line (4). The dielectric support structure (14) is made of SU-8 photoresist.

3. The Ω-shaped micro-coaxial chip structure according to claim 1, characterized in that: A positioning hole (6) is provided on the outer conductor.

4. The Ω-shaped micro-coaxial chip structure according to claim 1, characterized in that: The curvature of the curved rectangular coaxial line (4) does not exceed one-half of a circle arc.

5. An ultra-wideband coaxial interconnect structure, characterized in that: The invention comprises at least one Ω-shaped micro-coaxial chip structure as described in any one of claims 1 to 4; a first rectangular coaxial interface (1) is interconnected with a circular coaxial interface, and is connected to a rectangular coaxial interface of an external device through a second rectangular coaxial interface (2).

6. The ultra-wideband coaxial interconnect structure according to claim 5, characterized in that: The second rectangular coaxial interface (2) is directly connected to the waveguide interface.

7. A radio frequency test and calibration system for an ultra-wideband coaxial interconnect structure, characterized in that: The second rectangular coaxial interfaces (2) of the two Ω-shaped micro-coaxial chip structures are directly connected, and the two first rectangular coaxial interfaces (1) are respectively connected to the standard circular coaxial connector (7); or the first rectangular coaxial interface (1) is connected to the standard circular coaxial connector (7), and the second rectangular coaxial interface (2) is an air open circuit structure (9) or a short circuit plate structure (10) is provided; or the second rectangular coaxial interfaces (2) of the two Ω-shaped micro-coaxial chip structures are connected through a rectangular coaxial line (11), and the two first rectangular coaxial interfaces (1) are respectively connected to the standard circular coaxial connector (7); or the first rectangular coaxial interface (1) is connected to the standard circular coaxial connector (7), and the second rectangular coaxial interface (2) is connected to the patch load structure (15).

8. A radio frequency test and calibration method for an ultra-wideband coaxial interconnect structure, characterized in that: Based on the TRL calibration method, through calibration is achieved by directly connecting two second rectangular coaxial interfaces (2) of the Ω-shaped micro-coaxial chip structure, and respectively connecting two first rectangular coaxial interfaces (1) to standard circular coaxial connectors (7); reflection calibration is achieved by connecting the first rectangular coaxial interface (1) to the standard circular coaxial connector (7), and the second rectangular coaxial interface (2) is an air open circuit structure (9) or a short circuit plate structure (10); line calibration is achieved by connecting two second rectangular coaxial interfaces (2) of the Ω-shaped micro-coaxial chip structure through a rectangular coaxial line (11), and respectively connecting two first rectangular coaxial interfaces (1) to standard circular coaxial connectors (7), and rectangular coaxial lines (11) of different lengths are used during the calibration process.

9. The radio frequency test and calibration method of the ultra-wideband coaxial interconnect structure according to claim 8, characterized in that: Based on the SOLT calibration method, the through calibration is achieved by directly connecting two second rectangular coaxial interfaces (2) of a micro-coaxial chip structure of a similar Ω shape, and respectively connecting two first rectangular coaxial interfaces (1) to standard circular coaxial connectors (7); the open circuit calibration is achieved by connecting the first rectangular coaxial interface (1) to the standard circular coaxial connector (7), and the second rectangular coaxial interface (2) is an air open circuit structure (9); the short circuit calibration is achieved by connecting the first rectangular coaxial interface (1) to the standard circular coaxial connector (7), and the second rectangular coaxial interface (2) is a short circuit plate structure (10); and the load calibration is achieved by connecting the first rectangular coaxial interface (1) to the standard circular coaxial connector (7), and the second rectangular coaxial interface (2) is connected to a patch load structure (15).

10. Application of the ultra-wideband coaxial interconnect structure radio frequency test calibration method according to claim 8 or 9 in ultra-wideband radio frequency testing, characterized in that: Used for DC to 67 GHz, DC to 110 GHz, DC to 145 GHz, and DC to 220 GHz ultra-wideband RF testing.

Images