3dB bridge

Abstract

The invention discloses a 3dB bridge which comprises a multi-layer dielectric body, and a first coupling line and a second coupling line are arranged on the two opposite sides of the multi-layer dielectric body respectively and are overlapped on the wide side of a coupling part. The first coupling line and the second coupling line are respectively divided into parallel finger-shaped conductor sections at the coupling part, and the adjacent finger sections correspond in a cross-layer staggered manner to form a multi-scale coupling channel of the same coupling part; corresponding input ends and output ends are respectively led out from the first coupling line and the second coupling line; and a parasitic resonance unit which is electromagnetically coupled with the finger section is arranged in the multilayer dielectric body at a distance d1 from the transverse edge of the coupling part. The 3dB bridge enables in-band coupling to be self-balanced along with frequency, a parasitic unit compensates a band edge in situ in a near field, the problem that single-scale coupling and boundary cannot be quantized is solved, wider fractional bandwidth, flatter amplitude and phase and improvement of band edge directivity and port isolation are achieved, repeatability and mass production consistency are ensured through d1, d2, T, k1 and k2 constraints, and the 3dB bridge adapts to co-fired ceramic packaging.

Description

TECHNICAL FIELD

[0001] The present application relates to a bridge, in particular to a 3dB bridge. BACKGROUND

[0002] The cellular mobile communication evolves to 5G / 5G-A / 6G and massive MIMO (mMIMO), the RF front-end module needs to realize wide fractional bandwidth, low insertion loss, flat amplitude and phase, high directivity and high port isolation in the middle and low frequency band such as sub-6GHz, and adapt to the high integration packaging and mass production process of LTCC / HTCC and other multi-layer ceramics. At the system level, the in-band flatness and band edge stability of the coupler affect the linearity and combining efficiency of the link such as transmit synthesis / receive distribution / loop calibration; the coordination of coupling field and port transition, shielding / grounding layout also relates to electromagnetic compatibility and reliability.

[0003] The common implementation of existing 3dB bridge (directional coupler) includes: uniform coupling microstrip / strip line structure in the same layer or opposite layers; Lange interdigital coupler with band cross-bridge; branch coupler based on quarter wavelength; and structure for realizing strong coupling by broadside coupling in multi-layer medium. To expand the bandwidth and shape the amplitude and phase, multiple sections of cascaded / segmented gradual changes are often used in engineering, or open / short stub compensation units are set outside the main coupling line; coaxial-ribbon line transition is often used for packaging interconnection, and ground / shielding structure is often used to reduce reflection.

[0004] However, the above-mentioned schemes generally have two key deficiencies: Most topologies work at a single equivalent scale, making it difficult to form parallel channels dominated by low and high frequencies in the same coupling section, making it difficult to self-balance the in-band coupling rate with frequency changes, and limiting the amplitude and phase flatness; Common compensation units are often arranged outside or on the outside of the coupling domain, and the near-field coupling strength and geometric boundary of the coupling field are difficult to quantify and constrain, making it difficult to selectively and controllably correct the coupling and phase at the band edge.

[0005] Therefore, there is an urgent need for a multi-scale coupling channel to be constructed in the same coupling section to suppress the in-band fluctuation, and the resonant compensation unit to be arranged in the quantifiable geometric distance band within the multi-layer medium body, so that the near-field, on-site and controlled band edge compensation between the coupling domain is realized, thereby improving the directivity and isolation while ensuring the implementation repeatability. SUMMARY

[0006] The present application aims to provide a kind of in the same coupling part by the finger conductor segment of cross-layer staggered formation multi-scale coupling channel, and in the medium inside the coupling part or its adjacent predetermined distance range, electromagnetic coupling parasitic resonance unit with the finger conductor segment is arranged to carry out near-field in situ compensation to passband edge, so as to realize wide fractional bandwidth, in-band amplitude and phase flat 3dB electric bridge while keeping compact size and low insertion loss.

[0007] The technical scheme adopted by the present application to solve the above problems is: a 3dB electric bridge, comprising a multilayer dielectric body and a first coupling line and a second coupling line arranged on opposite layers of the multilayer dielectric body.

[0008] The first coupling line and the second coupling line are oppositely arranged in a wide-side overlapping manner in the coupling part along the signal coupling direction, and the coupling part is defined as the wide-side overlapping area of the first coupling line and the second coupling line.

[0009] The first coupling line and the second coupling line are each divided into a plurality of parallel finger conductor segments in the coupling part, and the adjacent finger conductor segments correspond to each other in cross-layer staggering in the normal projection plane perpendicular to the layer plane of the multilayer dielectric body, so as to form a multi-scale coupling channel in the same coupling part.

[0010] The first coupling line leads to form a first output leg and a first input leg, and the free end of the first output leg is provided with a first output terminal, and the free end of the first input leg is provided with a first input terminal.

[0011] The second coupling line leads to form a second output leg and a second input leg, and the free end of the second output leg is provided with a second output terminal, and the free end of the second input leg is provided with a second input terminal. And, in the coupling part region of the multilayer dielectric body within the predetermined distance range of the lateral edge of the coupling part, or in the adjacent dielectric region of the multilayer dielectric body and continuous with the coupling part, a parasitic resonance unit electromagnetically coupled with the finger conductor segment is arranged to compensate for the coupling frequency characteristics of the coupling part.

[0012] Wherein, the lateral edge of the coupling part is the coupling part boundary in the orthogonal direction relative to the signal coupling direction; the predetermined distance range is the distance band of the geometric distance d measured in the lateral direction in the multilayer dielectric body with the lateral edge as the starting boundary, falling into the interval k1T, k2T, T is the medium thickness of the multilayer dielectric body at the coupling part, and k1 and k2 are dimensionless coefficients greater than zero.

[0013] Preferably, the plurality of finger conductor segments located in the coupling section include long fingers and short fingers, and are staggered along the signal coupling direction, wherein the long fingers are used to dominate low frequency coupling, the short fingers are used to dominate high frequency coupling, and the two layers of the finger conductor segments maintain a cross-layer corresponding relationship of wide-side overlapping in the coupling section.

[0014] Preferably, the finger conductor segments are arranged in a transverse direction on a normal projection plane perpendicular to the layer surface of the multilayer dielectric body to form at least one finger row; the parasitic resonance unit is arranged in the multilayer dielectric body, and a geometric distance d1 measured in the transverse direction with respect to the transverse edge of the coupling section satisfies d1∈[0.5T, 2T].

[0015] Preferably, the bridge includes a phase compensation structure; the coupling section is defined as a coupling segment in the signal coupling direction, and the coupling segment is an effective coupling length region of the coupling section; the phase compensation structure is arranged at the end of the coupling segment, and includes a side edge coupling transition segment and / or an end capacitive wing and / or a first notch to reduce the phase velocity difference between even modes and odd modes and improve directivity.

[0016] Wherein, the even mode is a propagation mode in which the first coupling line and the second coupling line are in phase, and the odd mode is a propagation mode in which the first coupling line and the second coupling line are in anti-phase.

[0017] Preferably, the bridge includes a packaging module for carrying the multilayer dielectric body and leading the first input end, the first output end, the second input end and the second output end out of the packaging module.

[0018] Preferably, the multilayer dielectric body is an LTCC and / or HTCC ceramic substrate.

[0019] Preferably, the coupling section is segmented into two or three segments along the signal coupling direction, and the finger width, finger length, finger spacing and / or effective layer spacing of each segment are different, so as to equivalently form multi-section coupling, thereby expanding the fractional bandwidth and improving the coupling flatness.

[0020] Preferably, the 3dB bridge comprises a geometry regulating unit arranged in the multilayer dielectric body, and a geometric distance d2 between the geometry regulating unit and the lateral edge of the coupling part is within the predetermined distance range; the geometry regulating unit is configured to adjust the rate of change of the coupling degree of the coupling part with frequency, the echo of the first input end / first output end / second input end / second output end, and the port isolation of the target operating frequency band edge when the 3dB bridge is in operation; the geometry regulating unit is a metal wing or a tuning slot or a second notch; wherein the geometric distance d2 is the minimum geometric distance between the geometry regulating unit and the lateral edge of the coupling part in the lateral direction, and d2∈[k1·T,k2·T].

[0021] Preferably, the geometry regulating unit is a metal wing, which is arranged in the multilayer dielectric body and integrally formed with the finger conductor segment of the first coupling line and / or the second coupling line, and extends from the end or side of the finger conductor segment in the lateral direction.

[0022] Preferably, the geometry regulating unit is a tuning slot or a second notch; the tuning slot is located in the multilayer dielectric body and is opened on the first coupling line and / or the second coupling line; the second notch is located in the multilayer dielectric body and is cut along the edge of the first coupling line and / or the second coupling line.

[0023] The beneficial effects of the embodiments in the present application are as follows: 1. By arranging the first coupling line and the second coupling line in the coupling part in a wide-side overlapping manner, and by dividing the first coupling line and the second coupling line into a plurality of parallel finger conductor segments in the coupling part and making adjacent finger segments correspondingly staggered across layers in the normal projection plane, a multi-scale coupling channel is constructed in the same coupling part; and by arranging a parasitic resonance unit in the multilayer dielectric body and electrically coupled with the finger conductor segment at a predetermined distance band d1∈[k1·T,k2·T] with the coupling part lateral edge as the starting boundary, the band edge compensation is realized, so that the technical problems of the prior art, such as the difficulty of self-balancing of the in-band coupling with frequency, the unquantifiable coupling domain / coupling boundary of the compensation unit, and the difficulty of selective correction of the passband edge amplitude and phase, are effectively solved, thereby realizing wider fractional bandwidth, flatter in-band amplitude and phase, significantly improved band edge directivity and port isolation in the low frequency band (including sub-6GHz), and obtaining the repeatability and consistency of near-field local compensation by the geometric constraints of d1, T, k1, and k2, which is suitable for engineering landing of high-integration packaging processes such as LTCC / HTCC.

[0024] 2. Due to the technical means that the first coupling line and the second coupling line are divided into long fingers and short fingers in the coupling section, and the two layers of finger-shaped conductor segments are staggered in the signal coupling direction, and the two layers of finger-shaped conductor segments keep the cross-layer corresponding relationship of the wide edge overlap, the low-frequency is dominated by the long finger and the high-frequency is dominated by the short finger in the same coupling section, which effectively solves the technical problems of the single scale coupling in the prior art, such as the large rate of in-band coupling with frequency, the amplitude and phase unevenness, and the difficulty in considering the low / high frequency response, and further realizes the wider fractional bandwidth, the more flat in-band amplitude and phase, and the more stable group delay characteristics, and keeps the comprehensive technical effects of strong coupling and low insertion loss under the given coupling length.

[0025] 3. Due to the technical means that the finger-shaped conductor segments are arranged to form at least one finger row in the transverse direction of the normal projection plane, and the parasitic resonance unit is arranged in the multi-layer medium body, and the geometric distance d1 of the parasitic resonance unit from the transverse edge of the coupling section is controlled in [0.5T, 2T], the near-field, in-situ and quantitative energy exchange in the strong field region near the transverse edge of the coupling section can be realized, which effectively solves the technical problems of the prior art, such as the compensation unit being located outside the coupling domain, the weak selective modification ability of the passband edge, and the poor repeatability of the effect, which are caused by the unquantifiable coupling strength and geometric boundary, and further realizes the technical effects of significantly improving the band edge directionality and port isolation, minimizing the in-band influence of compensation while keeping the in-band amplitude and phase flat, and enhancing the consistency and repeatability under manufacturing tolerance.

[0026] 4. Due to the technical means that the phase compensation structure (side coupling transition section and / or end capacitive fin and / or first notch) is arranged at the end of the coupling section, and the even / odd mode propagation is geometrically matched at the end with the effective coupling length of the coupling section as the explicit object, the phase velocity difference between the even mode and the odd mode can be flattened in-situ and the end reflection phase distortion can be suppressed, which effectively solves the technical problems of the prior art, such as the directionality decline, the insufficient band edge isolation, and the in-band and out-of-band amplitude fluctuation difficult to be comprehensively optimized caused by the mismatch of the phase velocity of the even / odd mode, and further realizes the comprehensive technical effects of wider fractional bandwidth, flatter in-band amplitude and phase, significantly improved band edge directionality and port isolation in the target frequency band (including sub-6GHz), and repeatable manufacturing consistency and lower insertion loss by parameterized geometry.

[0027] 5. By setting a geometric regulation unit in the multilayer medium body, and performing the nearest edge minimum geometric distance constraint on the relative coupling part transverse edge with a predetermined distance band d2∈[k1·T, k2·T], and the geometric regulation unit adopts the engineered geometric features such as metal wing, tuning slot hole, and second notch to fine-tune the coupling body in situ, the technical problems in the prior art that the compensation unit is far away from the coupling domain, the near-field coupling strength and the boundary are not quantifiable, the parameter shaping depends on trial and error, and the consistency is poor are effectively solved, thereby realizing the accurate shaping of the change rate of the coupling degree with frequency, reducing the four-port return under the premise of not destroying the in-band flatness, and significantly improving the directivity and port isolation of the target frequency band edge, while enhancing the repeatability and mass production consistency under the manufacturing tolerance. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A schematic structural diagram of a first coupling line and a second coupling line in a coupled state in a preferred embodiment of the present application is shown.

[0029] Figure 2 A schematic top view of a first coupling line and a second coupling line in a coupled state in a preferred embodiment of the present application is shown.

[0030] Figure 3 An exploded view of a first coupling line and a second coupling line arranged on both sides of a multilayer medium body in a preferred embodiment of the present application is shown.

[0031] Figure 4 A schematic structural diagram of a first coupling line and a second coupling line arranged on both sides of a multilayer medium body in a preferred embodiment of the present application is shown.

[0032] Figure 5 A schematic sectional view of a first coupling line and a second coupling line placed in a packaging module in a preferred embodiment of the present application is shown.

[0033] Figure 6 A schematic structural diagram of a first coupling line and a second coupling line placed in a packaging module in a preferred embodiment of the present application is shown.

[0034] Wherein: 10, multilayer medium body; 20, first coupling line; 210, first input pin; 220, first output pin; 30, second coupling line; 310, second input pin; 320, second output pin; 40, coupling part; 50, finger conductor; 510, long finger; 520, short finger; 60, first input end; 70, first output end; 80, second input end; 90, second output end; 1000, packaging module; 1010, parasitic resonance capacitor. DETAILED DESCRIPTION

[0035] The specific embodiments of the present application will be further described in conjunction with the drawings and examples. The following examples are used to illustrate the present application but not to limit the scope of the present application.

[0036] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0037] In the description of the present application, it needs to be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication between the two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0038] Referring to Figures 1 to 6 A 3dB bridge is provided in a preferred embodiment of the present application. Most of the existing 3dB bridges operate at a single equivalent scale, which is difficult to form parallel channels dominated by low frequency and high frequency in the same coupling part 40, resulting in difficulty in self-balancing the in-band coupling rate with frequency, and limited amplitude and phase flatness. Moreover, common compensation units are usually arranged outside the coupling domain or on the outside branch, and the near-field coupling strength and geometric boundary of the coupling field are difficult to quantify and constrain, and the coupling and phase of the passband edge are difficult to selectively and controllably correct.

[0039] To solve the above problems, a preferred embodiment of the present application proposes a 3dB bridge, which comprises a multilayer dielectric body 10 and a first coupling line 20 and a second coupling line 30 arranged on opposite layers of the multilayer dielectric body 10. The first coupling line 20 and the second coupling line 30 are oppositely arranged in a wide edge overlapping manner in a coupling part 40 along a signal coupling direction, and the coupling part 40 is defined as the wide edge overlapping area of the first coupling line 20 and the second coupling line 30. The first coupling line 20 and the second coupling line 30 are each divided into a plurality of parallel finger-shaped conductors 50 segments in the coupling part 40, and the adjacent finger-shaped conductor 50 segments are staggered corresponding to the layers in the normal projection plane perpendicular to the layers of the multilayer dielectric body 10, so as to form a multi-scale coupling channel in the same coupling part 40. The first coupling line 20 is led out to form a first output leg 220 and a first input leg 210, the free end of the first output leg 220 is provided with a first output end 70, and the free end of the first input leg 210 is provided with a first input end 60. The second coupling line 30 is led out to form a second output leg 320 and a second input leg 310, the free end of the second output leg 320 is provided with a second output end 90, and the free end of the second input leg 310 is provided with a second input end 80. In the coupling part 40 region within the multilayer dielectric body 10 and within a predetermined distance range of the transverse edge of the coupling part 40, or in the adjacent dielectric region within the multilayer dielectric body 10 and continuous with the coupling part 40, a parasitic resonance capacitor 1010 is arranged to electromagnetically couple with the finger-shaped conductor 50 segment, for compensating the coupling frequency characteristics of the coupling part 40. Wherein, the transverse edge of the coupling part 40 is the boundary of the coupling part 40 in the direction orthogonal to the signal coupling direction; the predetermined distance range is a distance band in which the geometric distance d1 measured in the transverse direction with the transverse edge as the starting boundary falls within the interval [k1T, k2T] in the multilayer dielectric body 10, T is the dielectric thickness of the multilayer dielectric body 10 at the coupling part 40, and k1 and k2 are dimensionless coefficients greater than zero.

[0040] Specifically: The multilayer dielectric body 10 preferably adopts a low-temperature or high-temperature co-fired ceramic laminated structure, has an upper outer surface and a lower outer surface, and internally configures dielectric layers and metal layers for grounding, shielding or mechanical support.

[0041] The first coupling line 20 is arranged on the upper outer surface of the multilayer dielectric body 10, and the second coupling line 30 is arranged on the lower outer surface of the multilayer dielectric body 10. The two coupling lines are oppositely arranged in a wide-side overlapping manner in the coupling section 40 extending along the signal coupling direction, and the coupling section 40 is defined as the wide-side overlapping area of the first coupling line 20 and the second coupling line 30 in the interlayer direction. The coupling section 40 is distributed in a strip shape along the signal coupling direction, and the transverse edges are jointly defined by the outer boundaries of the two coupling lines on the normal projection plane. The thickness of the dielectric at the coupling section 40 is denoted as T, which is equal to the geometric thickness of the multilayer dielectric body 10 between the upper outer surface and the lower outer surface.

[0042] In the coupling section 40, the first coupling line 20 and the second coupling line 30 are each divided into a plurality of parallel finger conductors 50 segments. Each finger conductor 50 segment is arranged side by side in the transverse direction on the normal projection plane and is cross-layer staggered with respect to the finger conductors 50 segments on the opposite outer surface: a certain finger conductor 50 segment located on the upper outer surface overlaps with the adjacent finger conductor 50 segment located on the lower outer surface in the interlayer direction, but forms a staggered relationship in the signal coupling direction and the transverse direction, thereby forming a multi-scale coupling channel with different equivalent overlapping scales in the same coupling section 40. The wide sides of each finger conductor 50 segment maintain an overlapping relationship in the interlayer direction to ensure the cross-layer coupling strength and directionality.

[0043] The first coupling line 20 is respectively led out at both ends of the coupling section 40 to form a first input pin 210 and a first output pin 220, and the free end of the first input pin 210 is a first input end 60, and the free end of the first output pin 220 is a first output end 70. The second coupling line 30 is respectively led out at both ends of the coupling section 40 to form a second input pin 310 and a second output pin 320, and the free end of the second input pin 310 is a second input end 80, and the free end of the second output pin 320 is a second output end 90. Each end portion is preferably connected to an external circuit in the form of a solder pad or a metal lead.

[0044] To compensate for the coupling frequency characteristics, a parasitic resonance capacitor 1010 is arranged in the multilayer dielectric body 10 within a predetermined distance range from the transverse edge of the coupling section 40. The predetermined distance range takes the transverse edge of the coupling section 40 as the starting boundary, and the geometric distance d1 measured in the transverse direction falls within the distance band [k1·T, k2·T]. The parasitic resonance capacitor 1010 is coupled with the finger conductor 50 segment through near-field electromagnetic interaction. The parasitic resonance capacitor 1010 can be realized by forming a metalized island, a nearly closed loop, a metal sheet with a slit, or an equivalent inductance-capacitance network inside the dielectric; it is preferably not directly electrically connected with the first coupling line 20 and the second coupling line 30 to maintain the controllability of selective compensation.

[0045] The material, dielectric constant and loss tangent of the multilayer medium body 10 can be selected according to the target frequency band and packaging process; the conductor pattern preferably adopts a low-resistance metal film or a metal paste sintering layer. To constrain radiation and stabilize coupling, a ground metal layer and via belt can be provided in the adjacent inner layer of the coupling part 40 to improve field distribution and return under the condition of external surface wiring.

[0046] When a signal is injected from any input terminal, the signal propagates in the coupling part 40 along the signal coupling direction. Since the first coupling line 20 and the second coupling line 30 are located on the opposite two sides of the outer surface and form a wide side overlap in the interlayer direction, the interlayer electric field is enhanced in the strip area and strong coupling is generated. The cross-layer staggered topology composed of parallel finger conductors 50 segments in the coupling part 40 provides multiple equivalent overlap scales: larger equivalent overlap scales are more sensitive to low frequency components, smaller equivalent overlap scales are more sensitive to high frequency components, and both act in parallel in the same coupling domain, making the in-band coupling self-balancing with frequency changes, thereby suppressing amplitude and phase fluctuations.

[0047] The parasitic resonance capacitor 1010 provided in the medium interior and satisfying d1∈[k1·T, k2·T] is in the near-field range of the transverse strong field of the coupling part 40, and the parasitic resonance selectively couples with the coupling field at the edge of the target working frequency band, providing in-situ amplitude and phase compensation to correct the directivity and isolation at the passband edge. Since there is no direct electrical connection, the parasitic resonance capacitor 1010 has little disturbance to in-band transmission, while having targeted adjustment capability for the band edge. After coupling, the signal is led out by each output pin, and the four-port realizes the expected power distribution and directional coupling relationship.

[0048] The embodiment is suitable for radio frequency front-end, array feed network and general microwave module of mobile communication base station or terminal, especially for wideband directional coupling application in low and medium frequency bands. The device is preferably installed in a multilayer ceramic package or a module carrier board, and when wired on the outer surface, it is recommended to configure a continuous ground layer or metal shield outside the coupling part 40 to reduce radiation and environmental sensitivity; the working environment meets the temperature, humidity and mechanical strength requirements of conventional electronic devices. The stack and boundary conditions around the coupling part 40 should be consistent with the design to avoid coupling deviation caused by environmental changes.

[0049] In this embodiment, by using the technical means of arranging the first coupling line 20 and the second coupling line 30 on the opposite outer surfaces of the multilayer medium body 10 in a wide edge overlapping manner, forming a multi-scale coupling channel through the cross-layer stagger of the parallel finger-shaped conductor 50 segments in the same coupling part 40, and arranging the parasitic resonance capacitor 1010 electromagnetically coupled with the finger-shaped conductor 50 segments in the predetermined distance band with the coupling part 40 as the boundary, the technical problems of the prior art that the single-scale coupling leads to the difficulty in self-balancing of the in-band coupling rate with frequency and the difficulty in selective correction of the passband edge amplitude and phase due to the distance of the compensation unit from the coupling domain are effectively solved, and the technical effects of expanding the fractional bandwidth, making the in-band amplitude and phase more flat, significantly improving the band edge directivity and port isolation, and achieving the implementation repeatability and mass production consistency brought by in-situ compensation are achieved.

[0050] It should be noted that, in order to maintain the relationship of electromagnetic coupling without direct conduction with the first coupling line 20 and the second coupling line 30, the parasitic resonance capacitor 1010 is preferably a suspended metal resonance body or a quasi-suspended resonance body weakly connected with the ground reference. In the LTCC / HTCC stack, any one of the following three types of equivalent structures (or two / three combined) can be used: The capacitive patch resonance body (planar patch / slit patch) has a closed or nearly closed metal patch shape, which can be rectangular, elliptical or polygonal with rounded corners. A slit can also be formed in the patch to form a slit patch. Its coupling mode is mainly capacitive coupling with the edge electric field of the finger-shaped conductor 50 segment, and the band edge capacitor is selectively compensated. The capacitive patch resonance body is placed on the internal metal layer adjacent to the coupling part 40 (not the outer surface layer), and is separated from the first coupling line 20 and the second coupling line 30 on the outer surface by the multilayer medium body 10.

[0051] The ring-shaped resonance body can be a closed metal ring or an open ring with a single slit or double slits, and can be a rectangular ring, a circular ring or an elliptical ring. The ring-shaped resonance body can be capacitively coupled with the coupling line through the ring slit, and can also be inductively coupled with the main line current through the ring current to achieve inductance-capacitance hybrid compensation, which is suitable for fixed-point enhancement of band edge directivity and isolation. The ring-shaped resonance body is placed on the internal metal layer adjacent to the coupling part 40; if necessary, a small amount of ground via is arranged on the outer side of the ring to form a weak shield and stabilize the resonance Q value.

[0052] The metal column disc resonance body, i.e. the via column with a top disc / bottom disc, has the specific structure that the metalized via serves as an equivalent inductor, and a metal capacitor disc is arranged at one end or both ends of the via to form a compact LC resonance body. The metal column disc resonance body is capacitively coupled with the edge field of the finger-shaped conductor 50 segment through the capacitor disc, and the via column forms a small amount of magnetic coupling with the surrounding loop. The via column penetrates several layers of medium, but is not connected with the first / second coupling line 30; the capacitor disc is located on the internal layer close to the coupling domain.

[0053] The three types of structures meet the requirements of electromagnetic coupling and non-direct conduction. In actual engineering, the patch type main compensation is usually selected according to the target band edge position and compensation amount, the ring type is used for fine tuning directivity, and the metal column disc resonant body is usually used for micro area compact layout or thickness limited situation.

[0054] The parasitic resonant capacitor 1010 is a metal pattern or pattern-via combination embedded in the multi-layer dielectric body 10, which is separated from the first coupling line 20 and the second coupling line 30 by a dielectric layer and is not electrically connected to the two coupling lines. In order to stabilize the resonant frequency and Q value, a reference ground layer can be arranged below or above the layer where the parasitic resonant capacitor 1010 is located; if necessary, a small area edge of the parasitic resonant capacitor 1010 is grounded or semi-grounded by a high-impedance and short-path via to form a "weak constraint boundary", but the coupling with the main line is still mainly realized through electromagnetic near field.

[0055] In the LTCC / HTCC, the parasitic pattern adopts the conventional metal paste printing and co-firing or metal film deposition and sintering process to avoid crossing the laminated joint; the aperture and disc surface of the via column and disc structure are consistent with the process standard, which is beneficial to the control of mass production tolerance.

[0056] In addition, it also needs to be clear that the position and distribution rule of the parasitic resonant capacitor 1010, that is, the lateral, longitudinal and normal three-dimensional constraints.

[0057] First of all, it is the lateral constraint. Taking the lateral edge of the coupling part 40 as the starting boundary, the minimum geometric distance d1 of the nearest side in the lateral direction needs to fall into the predetermined distance band. This ensures that the parasitic resonant capacitor 1010 is in the strong near field region, realizing in-situ and quantifiable coupling.

[0058] Then, it is the longitudinal distribution (along the signal coupling direction). A set of parasitic resonant capacitors 1010 can be arranged at each of the two end band edge sensitive areas of the coupling part 40 for symmetric compensation of low band edge / high band edge; or a set of them can be arranged in the middle of the coupling section for flattening the in-band slope while not damaging the directivity at the end. Specifically, mirror-symmetrical arrangement can be adopted, and the pair of parasitic resonant capacitors 1010 are symmetrically placed about the electrical center of the coupling section to suppress the directivity degradation caused by the imbalance of even / odd modes. In addition, if the fluctuation at the high frequency end is larger, the parasitic resonant capacitor 1010 near the high frequency end can be appropriately close to the lateral edge or its equivalent capacitance / loop can be increased; vice versa.

[0059] Then, it is the normal layer position (vertical to the thickness direction of the medium), and the parasitic resonant capacitor 1010 is arranged on the one or two internal metal layers close to the coupling domain (in the multi-layer dielectric body 10), which can obtain stronger and more stable coupling; if it is necessary to weaken the effect or expand the tuning margin, the parasitic resonant capacitor 1010 can be sunk by one layer.

[0060] The relative position and cooperation mechanism of the parasitic resonance capacitor 1010 and the first coupling line 20 and the second coupling line 30 are as follows: The parasitic resonance capacitor 1010 is in a plane-edge or plane-plane relationship with the edge of the finger conductor 50 segment on the normal projection plane to obtain sufficient edge field coupling; for a ring or column-disk structure, the ring gap or the opening / edge of the capacitor disk can be directed to the edge of the finger conductor 50 segment to enhance the capacitive coupling.

[0061] The cooperation with the split-finger multi-scale is that when the low-frequency side deviation is large, the parasitic resonance capacitor 1010 can be designed to be capacitive-dominant (larger patch, narrower ring gap, larger disk surface), to improve the equivalent coupling and make up for the deficiency of the long finger 510 channel at the band edge. When the high-frequency side deviation is large, the parasitic resonance capacitor 1010 can be designed to be inductive-dominant or mixed (appropriate increase in ring circumference, increase in gap width, and increase in column-disk loop), to suppress excessive coupling or correct the phase, and to form a complement with the short finger 520 channel.

[0062] The selective correction of the parasitic resonance capacitor 1010 to the band edge and the self-balancing of the multi-scale finger array to the in-band slope jointly make the amplitude and phase more flat in the band, improve the directionality and isolation at the band edge, and at the same time avoid the parasitic response and process sensitivity caused by traditional external stubs.

[0063] It needs to be further explained that the dielectric thickness T at the coupling part 40 is determined according to the stack, and optional k1 and k2 are determined, and then the transverse allowed band is obtained; the distance between any outer edge of the parasitic resonance capacitor 1010 and the transverse edge of the coupling part 40 must satisfy the d1 constraint. Preferably, a patch type is selected as the main compensation. The patch side length, ring circumference or disk area has a monotonic relationship with the target band edge center frequency; without introducing specific numerical values, the starting point is "of the same order of magnitude as the finger width" in engineering, and then fine tuning is performed through simulation and sample regression. The patch or ring gap opening faces the edge of the coupling part 40; the parasitic resonance capacitors 1010 with the same function are arranged in pairs in mirror image to avoid mode imbalance. The parasitic resonance capacitor 1010 is placed in the one or two internal metal layers close to the coupling domain; if it is necessary to stabilize the Q value and reduce external influences, continuous ground can be configured on the back side and a moderate window can be left to avoid complete shielding leading to weak coupling. Moreover, the same set of metal and via rules as the main line are preferentially used; the parasitic resonance capacitor 1010 is prevented from crossing the laminated seam; structures sensitive to the band edge (such as ring gap, patch round corner, disk edge retreat) are reserved for small adjustment allowance, facilitating production correction.

[0064] In this embodiment, by embedding the parasitic resonance capacitor 1010 inside the multi-layer dielectric body 10 and controlling the distance d1 from the nearest edge of the coupling part 40 to a predetermined distance band as a geometric constraint, combined with the engineering of resonant shapes such as patch, ring or column-disk, and the directional arrangement of the edge field of the finger conductor 50 segment, the technical problems of the prior art, such as the compensation unit being far away from the coupling domain, the near-field coupling strength being unquantifiable, and the band edge being difficult to selectively correct, are effectively solved, thereby realizing the technical effects of significantly improving the band edge directivity and port isolation, reducing the return loss and insertion loss while maintaining the in-band amplitude and phase flatness, and improving the consistency and repeatability of mass production under manufacturing tolerance.

[0065] Further, the plurality of finger conductors 50 segments located in the coupling part 40 include two types of long fingers 510 and short fingers 520, and are arranged in an interleaved manner along the signal coupling direction, wherein the long fingers 510 are used to dominate low-frequency coupling, the short fingers 520 are used to dominate high-frequency coupling, and two layers of the finger conductors 50 segments maintain a wide edge overlapping cross-layer correspondence in the coupling part 40.

[0066] Specifically: The coupling part 40 of this embodiment is composed of a region formed by the first coupling line 20 and the second coupling line 30 in the interlayer direction. In order to introduce multi-scale coupling in the same coupling domain, each coupling line in the coupling part 40 is divided into a plurality of parallel finger conductors 50 segments. The finger conductors 50 segments include two types of relatively long long fingers 510 and relatively short short fingers 520. The long fingers 510 and the short fingers 520 are arranged in an interleaved manner along the signal coupling direction, and are horizontally arranged in the normal projection plane, and maintain a wide edge overlapping cross-layer correspondence with the finger conductors 50 segments of the opposite layer, so that the two side finger arrays form a stable electric field coupling channel in the interlayer direction.

[0067] The length of the long finger 510 is greater than that of the short finger 520, the end extends deeper into the overlapping area of the opposite finger array, and the equivalent overlapping length is longer, which is suitable for establishing a stronger coupling channel at a lower frequency. The length of the short finger 520 is relatively small, the end partially overlaps with the opposite finger array, and the equivalent overlapping length is shorter, which is suitable for forming dominant coupling at a higher frequency. In order to reduce reflection caused by sudden changes, the ends of the long fingers 510 and the short fingers 520 are preferably chamfered or rounded, and the edges between the fingers can be rounded or beveled to smooth the edge electric field. The material of the finger conductor 50 is a conductive metal pattern laid on the opposite conductor layer; the relative positioning of the two side finger arrays in the normal direction is preferably symmetrically aligned or slightly offset, so as to balance between coupling strength and process tolerance.

[0068] At the entrance and exit regions of the coupling section 40, the long fingers 510 and the short fingers 520 gradually transition from the solid main line to the array of fingers, and the line width and the interval of the transition section gradually change along the coupling direction to achieve a smooth transition from the main line to the multi-scale finger array. The segments of the finger-shaped conductors 50 maintain a parallel relationship, and the finger width, the finger interval, and the finger end shape determine the spatial filling rate and the edge field distribution of the coupling section 40, thereby determining the weight distribution of the multi-scale channel.

[0069] After the signal enters the coupling section 40 along the coupling direction, the wide edges of the two side finger arrays overlap in the interlayer direction, so that the electric field is concentrated in the medium between the finger arrays. Due to the difference in geometric scale between the long fingers 510 and the short fingers 520, there are two types of coupling channels with long and short equivalent overlap lengths in the same coupling domain. The long finger 510 channel is more sensitive to lower frequency electromagnetic fields and can provide main coupling at lower frequencies; the short finger 520 channel is more sensitive to higher frequency electromagnetic fields and can maintain or correct the coupling at higher frequencies. The long and short fingers 520 are staggered along the coupling direction, so that the local equivalent overlap length periodically switches within the micro-section scale, thereby forming a self-balancing in the same domain for the coupling slope with frequency, and suppressing the in-band amplitude and phase fluctuations.

[0070] During propagation, the wide edge overlap between the finger arrays ensures that the interlayer electric field component is dominant, the lateral parallelism makes the edge field distribution balanced, and the cross-layer correspondence reduces the phase velocity difference fluctuations caused by mode asymmetry. The gradual transition at the entrance and exit reduces end reflection and additional phase shift, so that the contributions of multi-scale coupling are superimposed in an approximately linear manner within the main passband, thereby obtaining a more flat coupling and phase response.

[0071] During the design and debugging stage, the comprehensive weight of the two types of channels is controlled by adjusting the number ratio, relative order, and staggered rhythm of the long fingers 510 and the short fingers 520; the edge field intensity and distribution are refined by fine-tuning the finger width and the finger interval; the sensitivity of the interlayer coupling strength is adjusted by changing the slight misalignment of the opposite side finger arrays in the normal direction; the end reflection and phase distortion are controlled by setting the geometric gradual transition at the entrance and exit. The coordinated optimization of the above parameters makes the coupling curve have a smaller slope within the target bandwidth, and maintains the stability of directionality and isolation at the band edge.

[0072] Without changing the basic principle, the combination of the long fingers 510 and the short fingers 520 can also use single-long-single-short alternation, double-long-single-short alternation, or non-equidistant staggered rhythm, to match different in-band flatness and band edge roll-off requirements. The finger end shape can be rectangular, bevelled, or rounded, and the finger gap can be equidistant or gradually changing, to suppress local standing waves. The corresponding relationship of the two side finger arrays in the normal direction can be completely aligned or slightly misaligned, to balance between coupling strength and process tolerance. If further reduction of end reflection is required, a longer geometric gradual transition can be set at the entrance and exit to make the transition from the main line to the finger array smoother.

[0073] In this embodiment, the coupling lines are divided into two types, long fingers 510 and short fingers 520, and staggered in the coupling direction, and the two side finger arrays overlap in the width direction, which effectively solves the technical problems of single scale coupling leading to difficult self-balancing of in-band coupling rate with frequency variation and amplitude and phase flatness, and achieves the technical effects of obtaining more flat coupling and phase response in the target frequency band, wider available bandwidth, and better consistency when process tolerance exists.

[0074] In some further embodiments, the segments of the finger conductor 50 are arranged in a transverse direction on a normal projection plane of the layer surface of the multilayer dielectric body 10 to form at least one finger array; the parasitic resonance capacitor 1010 is arranged in the multilayer dielectric body 10, and the geometric distance d1 measured in the transverse direction with respect to the transverse edge of the coupling part 40 satisfies d1 ∈ [0.5T, 2T].

[0075] Specifically: The normal projection plane is used to geometrically map the segments of the finger conductor 50 distributed on different bearing surfaces to the same observation plane, so as to determine the transverse spacing, overlap relationship and field distribution between each other. The finger array is composed of several equal-width or nearly equal-width finger segments, and the adjacent finger segments maintain a constant or slowly varying transverse gap. The end of the finger segment can be rounded or chamfered to weaken the edge electric field singular point. The finger array extends through the coupling part 40 along the signal coupling direction, and the overall direction of the finger array is orthogonal to the transverse direction. The planar position of the finger array is limited by the geometric center and the boundary of the coupling part 40.

[0076] The parasitic resonance capacitor 1010 is arranged on the inner metal layer of the multilayer dielectric body 10 or is composed of the inner metal pattern and the dielectric via hole, and is isolated from the coupling part 40 by the dielectric and is not directly conducted. The geometric distance from the nearest side of the parasitic resonance capacitor 1010 to the lateral edge of the coupling part 40 is denoted as d1, which is measured in the lateral direction and satisfies that d1 is within a predetermined distance band measured from the lateral edge of the coupling part 40 with the dielectric thickness T as the scale and limited by the coefficient interval. In order to obtain stable and controllable near-field coupling, the parasitic resonance capacitor 1010 is preferably arranged on the inner one or two metal layers close to the coupling part 40, and is in a facing relationship with the footprint in the normal projection plane, so that it mainly establishes capacitive or inductive-capacitive hybrid coupling with the edge field of the footprint. The parasitic resonance capacitor 1010 can be a metal patch, an open or nearly closed ring pattern, an equivalent inductive-capacitive body composed of a metalized via hole and a small metal disc on the top surface, and its size and the direction of the gap opening can be determined according to the band edge position of the target frequency band and the required compensation amount. In order to improve the arrangement repeatability and bidirectional consistency, the parasitic resonance capacitor 1010 is preferably placed in mirror symmetry with respect to the geometric center of the coupling part 40, and is aligned or quasi-aligned with the footprint in the long direction.

[0077] The relative orientation between the footprint and the parasitic resonance capacitor 1010 is selected according to the edge field maximization principle, that is, the edge of the opening, gap or capacitor disc of the parasitic resonance capacitor 1010 is preferentially oriented towards the edge of the footprint to enhance the local electric field coupling; when it is necessary to reduce the coupling strength or converge the resonance quality factor, the parasitic resonance capacitor 1010 can be sunk by one layer or a continuous ground can be arranged on the back thereof and a ground window can be opened to adjust the field leakage path. All metal patterns are formed by a conductor process matched with the multilayer dielectric body 10, and the installation mode is to complete the printing, deposition and patterning of the metal pattern before sintering or laminating, and then integrate with the dielectric to avoid position errors introduced by re-mounting in the late stage of the finished product.

[0078] When the coupling signal enters the coupling section 40 along the coupling direction, the finger array provides a main coupling field generated by the edge field regularly distributed along the transverse direction overlapping the interlayer wide side. In the normal projection plane, the transverse rhythm of the finger array determines the spatial distribution of the equivalent edge capacitance, thereby affecting the slope of the coupling with frequency and the local phase delay. The parasitic resonance capacitor 1010 is located in the predetermined distance band and in the near-field region of the coupling section 40 transverse strong field, and the intrinsic resonance exchanges energy with the main coupling field, thereby selectively modifying the coupling amplitude and phase at the edge of the target frequency band. Since the parasitic resonance capacitor 1010 is not directly connected to the main conductor, the in-band transmission is only mildly affected near the passband center, while significant directivity and isolation improvement can be achieved in the band edge region. In actual operation, by adjusting the shape size of the parasitic resonance capacitor 1010, the opening angle of the gap, and the layer position, the resonance point of the parasitic resonance capacitor 1010 can be aligned with the target band edge, and the coupling strength and compensation depth can be set by fine-tuning the specific value of d1 in the predetermined distance band.

[0079] After determining the medium thickness T and the geometric boundary of the coupling section 40, first complete the transverse layout of the finger array in the normal projection plane, so that adjacent finger segments satisfy the predetermined spacing and filling rate in the transverse direction, thereby obtaining a stable main coupling field distribution. Then, according to the position of the target band edge, the form of the parasitic resonance capacitor 1010 is selected, and the geometric center or the nearest side of the parasitic resonance capacitor 1010 is placed in the predetermined distance band, so that d1 satisfies the constraint. In the debugging stage, the effective capacitance or the equivalent loop length of the parasitic resonance capacitor 1010 is fine-tuned to correct the band edge response, and the transverse rhythm of the finger array is maintained without sudden changes; if there is in-band fluctuation, the layer position and the ground window opening size of the parasitic resonance capacitor 1010 are adjusted to converge, without changing the basic rhythm of the finger array, to maintain the continuity and repeatability of the main coupling.

[0080] The finger array can be a single column or a multi-column layout, and the transverse offset between the columns in the multi-column case is used to refine the edge field distribution; the transverse pitch of the finger segments can be constant or can vary along the coupling direction to achieve in-band slope fine-tuning. When the form of the parasitic resonance capacitor 1010 is selected from a patch, an open loop, and a via column with a metal disc, the available layer position, the degree of wiring congestion, and the band edge compensation depth can be considered; when further consistency is required, two symmetric parasitic resonance capacitors 1010 can be used for differential tuning by a small size difference. If the system is more sensitive to radiation, a continuous ground can be provided on the back of the parasitic resonance capacitor 1010 and a small size ground window can be opened to reduce the coupling to external fields and stabilize the resonance loss.

[0081] In this embodiment, by adopting the technical means of arranging at least one finger array in the transverse direction in the normal projection plane and arranging the parasitic resonance capacitor 1010 in the multi-layer medium body 10 in a manner that the distance to the nearest edge of the coupling part 40 is constrained by a predetermined distance band, the technical problems of weak band edge selective correction ability and poor repeatability caused by the difficulty in controlling the edge field of the finger array, the compensation unit far away from the coupling domain, and the unquantifiable coupling strength and geometric boundary are effectively solved, thereby realizing the technical effects of in-situ controllable compensation of amplitude and phase of the target band edge while maintaining the flatness in the band, improving the directivity and port isolation, and enhancing the consistency of mass production.

[0082] In some embodiments, a 3dB bridge includes a phase compensation structure. The coupling part 40 is defined as a coupling section in the signal coupling direction, which is the effective coupling length region of the coupling part 40. The phase compensation structure is arranged at the end of the coupling section and includes a side edge coupling transition section and / or an end capacitive fin and / or a first notch to reduce the phase velocity difference between even and odd modes and improve directivity. The even mode is a propagation mode with the same phase of the electric potential of the first coupling line 20 and the second coupling line 30, and the odd mode is a propagation mode with the opposite phase of the electric potential of the first coupling line 20 and the second coupling line 30.

[0083] Specifically: The coupling part 40 is defined as a region with a certain effective coupling length in the signal coupling direction, which is called a coupling section. The phase compensation structure (not shown in the figure) is arranged at the end of the coupling section, and its geometric features are continuously connected to the end of the coupling section and transition to the straight line section or transition region of the lead-out pin. The phase compensation structure includes one or more combinations of a side edge coupling transition section, an end capacitive fin, and a first notch.

[0084] The side edge coupling transition section is a gradually changing coupling band arranged along the lateral edge of the end of the coupling section. It continuously transitions the equivalent edge spacing of the coupling section to the edge spacing of the end connection section through tapered or diverging boundaries, and the shape can be a smooth curve or an approximate curve of multiple segments. The side edge coupling transition section is connected to the edge of the main body of the coupling section with a continuous tangent, avoiding additional reflections caused by sudden changes.

[0085] The end capacitive fin is a metal widening part arranged at the end of the coupling section, which is integrally formed with the end conductor and extends laterally. The outer contour of the fin smoothly connects with the end edge. The end capacitive fin adjusts the modal phase velocity of the end by increasing the equivalent ground capacitance of the end and the effective capacitance to the even mode field.

[0086] The first notch is a recessed structure cut along the end or side edge of the coupling segment, the notch is integrally formed with the end conductor and partially shrinks the conductor boundary in the transverse or oblique direction. The first notch adjusts the phase velocity of the odd mode by reducing the end equivalent edge capacitance or local equivalent width.

[0087] The phase compensation structure can be implemented with a metal pattern in the same layer as the coupling segment, with the same material and thickness as the coupling segment conductor. The connection between each geometric element and the coupling segment is a seamless continuous planar metal pattern connection, and the installation method is completed by the same conductor film forming and patterning process as the main body, ensuring integrated topography and positional accuracy. The profile and size of the phase compensation structure are determined according to the target frequency band, coupling degree target, and phase velocity difference of the even and odd modes, and are refined through simulation and sample regression.

[0088] There are two types of intrinsic propagation modes in the coupling segment: even mode and odd mode. The even mode is a propagation mode with the same phase of the potential of the two coupled lines, and the electric field is more concentrated outside the two lines; the odd mode is a propagation mode with opposite phase of the potential of the two coupled lines, and the electric field is mainly concentrated between the two lines. Due to the boundary conditions and incomplete symmetry of geometry, the equivalent capacitance and inductance of the even and odd modes are different, resulting in a deviation in the phase velocity of the two modes. This phase velocity difference is easily converted into a phase error at the end of the coupling segment and manifests as a decrease in directivity and isolation.

[0089] The phase compensation structure adjusts the phase velocity by applying differential equivalent loads to the two types of modes at the end. The end capacitance wing increases the equivalent capacitance of the even mode without significantly changing the coupling path of the odd mode, thereby reducing the phase velocity of the even mode. The first notch reduces the equivalent capacitance or local effective width of the odd mode without significantly changing the boundary conditions of the even mode, thereby increasing the phase velocity of the odd mode. The side edge coupling transition segment establishes a gradual boundary at the end edge, suppresses the energy redistribution and additional reflection of the modes at the end, and makes the above two end adjustments more stable and effective in a wide frequency range.

[0090] In actual operation, the signal propagates along the coupling segment to the end, and the phase compensation structure fine-tunes the equivalent capacitance and inductance of the even and odd modes, making their phase delays at the end consistent. This process does not require additional control or active adjustment, but relies solely on the passive characteristics of the geometric configuration. The action area of the phase compensation structure is continuously connected with the end of the coupling segment, and does not destroy the multi-scale coupling distribution in the coupling segment, while reducing the phase distortion in the port transition.

[0091] The phase compensation design first determines the adjustment emphasis according to the direction of the difference in phase velocity between the even mode and the odd mode in the coupling section. When the even mode phase velocity is too fast, the edge extension of the end capacitive wing is preferentially increased or the edge profile of the wing is made closer to the outside reference boundary to enhance the even mode end capacitance. When the local section odd mode phase velocity is too slow, a first notch is preferentially introduced at the corresponding position to reduce the odd mode end capacitance by locally narrowing the edge or forming an inward concave profile at the end. If both types of deviation coexist, the side edge coupling transition section is used to establish a smooth mode conversion window at the end, so that the combined adjustment of the wing and the notch presents a linear superposition characteristic.

[0092] At the connection between the end of the coupling section and the lead-out foot, the curvature of the conductor boundary is kept continuous and the smoothness of the transition length is controlled to suppress the excitation of the undesired high-order mode. The ground and shielding relationship between the phase compensation structure and the lead-out foot is kept consistent to avoid introducing new asymmetric boundaries at the end. The relative positions between the elements of the phase compensation structure are determined to avoid mutual shielding, ensuring that the influence of the wing on the even mode and the influence of the notch on the odd mode can be independently adjusted.

[0093] When stable phase velocity flattening needs to be achieved in a wider frequency band, a gradually changing curvature distribution can be used for the outer profile of the side edge coupling transition section, so that the edge spacing presents a flexible gradient along the coupling direction, thereby reducing the compensation sensitivity and improving the wideband robustness.

[0094] When the even mode end capacitance needs to be further enhanced, the end capacitive wing can adopt a bilateral symmetric outer extension form, and a round corner can be added to the outer edge of the wing to reduce the edge field concentration. When a stronger odd mode acceleration effect is needed, the first notch can adopt a trapezoidal or arc-shaped recess, and the recess depth can be gradually changed along the transverse direction or along the coupling direction to balance the phase velocity improvement and the in-band flatness. The side edge coupling transition section can be used simultaneously with the gradual change of the conductor width, and a double transition window is established at the end by the joint gradient of the edge and the width. If the system requires bidirectional symmetric directivity, the phase compensation structure can be symmetrically arranged at both ends of the coupling section, so that the phase velocity flattening at both ends meets the bidirectional working demand at the same time. If the reflection of the port transition needs to be further reduced, a small amplitude impedance transition geometry can be further arranged after the compensation area to make the phase flattening and impedance matching cooperate.

[0095] The phase compensation structure cooperates with the parasitic resonant capacitor 1010 and the bridge main body to mainly reflect that the bridge main body forms a certain coupling distribution and a mode propagation channel in the coupling section, the parasitic resonant capacitor 1010 selectively compensates the amplitude-phase response of the band edge in the near-field range close to the coupling domain, and the phase compensation structure geometrically balances the phase velocity difference of the even mode and the odd mode at the end of the coupling section. The three are divided in space and complementary in mechanism: the main body is responsible for the continuity and energy distribution of the in-band coupling, the parasitic structure is responsible for the local correction of the band edge, and the phase compensation is responsible for the modal phase alignment at the end. The parasitic resonant capacitor 1010 makes it easier for the target band edge to reach under small geometric perturbation, and the phase compensation eliminates the end phase drift that may be introduced by parasitic adjustment. Both of them work together to improve directivity and isolation while maintaining in-band flatness and stable port echo. In this way, without adding additional active control, a wideband, flat and higher directivity comprehensive performance can be achieved.

[0096] In the embodiment, by adopting the technical means of setting a side edge coupling transition section and / or an end capacitor wing and / or a first notch at the end of the coupling section to apply differential end load to the even mode and the odd mode to flatten the modal phase velocity difference, the technical problems of phase distortion at the end of the coupling section and mismatch of even and odd mode phase velocity in the prior art, which lead to decreased directivity and insufficient band edge isolation, are effectively solved, thereby realizing the technical effects of significantly improving directivity and port isolation while maintaining in-band amplitude and phase flatness, reducing end reflection, and having good production consistency.

[0097] In some embodiments, the coupling part 40 is segmented into at least two ends along the signal coupling direction, and the finger width, finger length, finger spacing and / or effective layer spacing of each segment are different, so as to equivalent form multiple coupling sections, thereby expanding the fractional bandwidth and improving the coupling flatness.

[0098] Specifically: The coupling part 40 is divided into multiple sections along the signal coupling direction. Each section still adopts the coupling topology of the array of finger-shaped conductors 50, but at least one of the finger width, finger length, finger spacing and effective layer spacing is different from each other. In order to ensure electromagnetic continuity, the geometric transition zone is used to transition between the two adjacent sections, and the transition zone and the two main sections are smoothly connected in planar profile.

[0099] The finger width is used to adjust the equivalent conductor width and edge electric field range of each section; the finger length is used to set the equivalent coupling length and sensitivity to different frequency components of the section; the finger spacing is used to adjust the concentration of the edge electric field and the coupling strength; and the effective layer spacing is determined by the medium stack thickness between the relative layers carrying the finger-shaped conductors 50 and the local windowing of the intermediate reference metal, and is used to refine the interlayer coupling. By selecting different parameter combinations in different sections, the coupling part 40 presents a stepped or gradually varying coupling distribution in the longitudinal direction.

[0100] The segmentation boundary of the coupling section 40 is preferably set at an integer period of the finger array rhythm to avoid introducing additional edge field discontinuity at the boundary. The finger conductors 50 within each segment maintain lateral parallelism, interlayer wide edge overlap and cross-layer correspondence, ensuring that the basic mechanism of strong coupling remains unchanged. The impedance transition zone is reserved between the two ends of the coupling section 40 and the lead-out pins, so that the reflection between the segmented coupling section 40 and the external port is suppressed. The conductor material is matched with the multilayer medium body 10, and is formed using conventional thick film or thin film processes; the interlayer alignment accuracy meets the finger array misalignment tolerance requirements.

[0101] The multi-segment coupling is equivalent to introducing distributed equivalent coupling coefficient and equivalent phase shift control along the propagation direction of the coupling section 40. Relatively larger finger width, smaller finger spacing and smaller effective interlayer spacing will enhance the coupling strength of the segment; relatively longer finger length will extend the equivalent coupling length of the segment and increase the weight of the low frequency component; relatively shorter finger length and moderately relaxed geometric parameters make the segment more sensitive to high frequency components. By adapting different parameter combinations in different segments, the overall slope of the coupling with frequency in the passband is mutually offset, so that a more flat amplitude and phase characteristics are obtained.

[0102] After the signal enters the coupling section 40 from one end, it successively experiences multiple segments with different coupling strengths. Each segment produces different degrees of phase delay and energy exchange for even and odd modes, and the gradual transition of adjacent segments further reduces interface reflection, so that the multi-segment coupling effect is approximately superimposed as a reduction in the slope in the band and controlled roll-off at the band edge. Through simulation and iteration of the regression sample, the designer can adjust the parameters of each segment to the optimal combination that meets the target in-band flatness and band edge directivity.

[0103] The determination of the number of segments and the length ratio of each segment should comply with the comprehensive trade-off of target bandwidth, directivity and insertion loss. Generally speaking, increasing the number of segments is beneficial to widening the bandwidth and refining the shaping, but it will increase the manufacturing complexity and sensitivity; therefore, it is preferred to shape with fewer segments and effective parameter differences. The geometric transition zone set between the two adjacent segments should have continuous boundary curvature and monotonous parameter gradient to suppress high-order mode excitation and local standing wave. The initial values of the parameters of each segment can be set according to the shape of the target coupling curve, following the principles of "stronger coupling in low frequency segments, moderate weakening of coupling in high frequency segments" or "buffering in the middle segment, shaping at both ends", and then fine-tuning the finger width, finger spacing and interlayer spacing in small steps to achieve fine matching. To avoid mismatch caused by process dispersion, it is recommended to use a more gradual geometric gradient in the segment that is most sensitive to coupling, and to reserve a boundary margin in the direction of alignment error.

[0104] In some alternative embodiments and alternatives, the segmentation manner can adopt a stepped or a gradual change. The stepped one emphasizes the discrete difference of the parameters of each segment, facilitating the realization of explicit coupling focus migration; the gradual change one emphasizes continuous change, being suitable for obtaining smaller ripple in the band. The parameter dimension can be changed individually or in linkage: for example, only by adjusting the finger spacing to realize segmentation; or in linkage on the finger width and the effective layer spacing to obtain a larger adjustable range. The segment length can be equal or be unequally distributed according to the frequency weight to match the target passband shape. For the case requiring stronger band edge control, segments with stronger parameter difference can be adopted at the position close to the band edge response more sensitive, while segments with mild parameter difference are adopted in the band to maintain flatness.

[0105] In the present embodiment, since the technical means of segmenting the coupling part 40 along the signal coupling direction and setting different finger width, finger length, finger spacing and or effective layer spacing in different segments to equivalently form multi-section coupling are adopted, the technical problems in the prior art that the single coupling topology leads to large rate of in-band coupling change with frequency, amplitude and phase flatness and difficulty in balancing the band edge roll-off and directivity are effectively solved, and the technical effects of expanding fractional bandwidth, suppressing in-band ripple and stabilizing band edge directivity and port isolation while maintaining low insertion loss and good matching are realized.

[0106] In some embodiments, the 3dB electrical bridge includes a geometric regulation unit arranged in the multilayer dielectric body 10, and the geometric distance d2 between the geometric regulation unit and the lateral edge of the coupling part 40 is within the predetermined distance range; the geometric regulation unit is configured to adjust the rate of change of the coupling degree of the coupling part 40 with frequency, the echo of the first input end 60 / the first output end 70 / the second input end 80 / the second output end 90 and the port isolation of the target operating frequency band edge when the 3dB electrical bridge is in the working state; the geometric regulation unit is a metal wing or a tuning slot or a second notch; wherein the geometric distance d2 is the minimum geometric distance between the geometric regulation unit and the lateral edge of the coupling part 40 in the lateral direction, and d2 ∈ [k1·T, k2·T].

[0107] Specifically: The geometric regulation unit (not shown in the figure) is arranged in the internal metal layer of the multilayer dielectric body 10 and is isolated from the coupling part 40 by medium without direct conduction. The minimum geometric distance between the geometric regulation unit and the lateral edge of the coupling part 40 in the lateral direction is recorded as d2, which is within the predetermined distance band defined by the upper and lower limits of the medium thickness, so as to ensure that the geometric regulation unit is in the near field range of the lateral strong field of the coupling part 40.

[0108] The geometric regulation unit can be a metal wing, a tuning slot, or a second notch. The metal wing is an integral metal widening part extending transversely outward from the end or side of the coupling line or the finger conductor 50 segment, and the outer contour is smoothly connected with the body conductor. Its function is to increase the local edge capacitance and change the equivalent capacitance distribution of the end or side. The tuning slot is a slit in the coupling line conductor pattern, which can penetrate the conductor width or form a nearly closed trend inside the conductor to extend the current path, introduce local equivalent inductance, and reduce equivalent edge capacitance, thereby changing the local reactance. The second notch is a recess formed by cutting along the edge of the coupling line or the finger conductor 50 segment, which weakens the edge electric field by narrowing the local equivalent width, reduces the equivalent capacitance, and finely adjusts the coupling strength of the adjacent coupling channels.

[0109] The three types of geometric features are realized by planar metal patterns, and the material and thickness are consistent with the main conductor. The installation method is to complete the metal pattern printing, deposition, and patterning before the dielectric stack is formed or co-fired, so that the geometric regulation unit is solidified with the stack, avoiding position errors introduced by post-mounting. The geometric regulation unit is preferably arranged facing the transverse edge of the coupling part 40 in the normal projection plane to improve the coupling efficiency with the edge electric field; its longitudinal position can be selected in the end adjacent or middle adjacent region of the coupling part 40 according to the target compensation frequency band, all of which are subject to the premise that d2 is in the predetermined distance band.

[0110] When the device is working, the coupling part 40 forms a main coupling field between the layers, and there is a strong edge electric field at the transverse edge. The geometric regulation unit is in the near-field region within the predetermined distance band, which can change the local equivalent capacitance and equivalent inductance to achieve fine shaping of the coupling degree with respect to the frequency change rate. The metal wing mainly increases the edge capacitance, tends to increase the low-end coupling or slow down the high-end coupling attenuation; the tuning slot mainly introduces equivalent inductance and reduces local capacitance, tends to suppress excessive high-end coupling or correct phase delay; the second notch mainly reduces the edge capacitance, tends to weaken the local coupling and smooth the phase change at the boundary.

[0111] In terms of port return, the geometric regulation unit changes the local reactance of the coupling part 40 and the lead-out segment to achieve reflection suppression at the inlet and outlet; in terms of band edge isolation, the geometric regulation unit selectively corrects the coupling and phase response of the band edge in a near-field and in-situ manner to improve the directivity and port isolation. In actual operation, by fine-tuning the size, opening orientation, layer position, and minimum distance from the transverse edge of the geometric regulation unit, its resonance and reactive reactance produce controlled energy exchange with the main coupling field in the target frequency band, thereby achieving comprehensive shaping of amplitude and phase and return.

[0112] First, the lateral edge position of the coupling part 40 and the medium thickness are determined to obtain a predetermined distance band. Then, the placement direction and opening direction of the geometric control unit are determined in the normal projection plane, so as to face the main coupling direction of the edge electric field, so as to improve the coupling efficiency and reduce the required geometric change amount. For the metal wing, the equivalent capacitance is adjusted by controlling the extension length and the contour curvature of the outer edge. For the tuning slot hole, the equivalent inductance and the equivalent capacitance are adjusted by controlling the length, the width and the direction of the slot. For the second notch, the local reactance is adjusted by controlling the depth and the edge topography of the recess. All the parameter adjustments are constrained by keeping d2 in the predetermined distance band, without changing the basic insulation relationship with the main conductor. In order to improve consistency, a mirror-symmetrical arrangement about the geometric center of the coupling part 40 can be used. In order to reduce the sensitivity in the wide frequency band, a slowly-varying contour or a multi-section small gradual change can be used in the longitudinal direction.

[0113] It should be noted that the geometric control unit is arranged inside the multi-layer medium body 10 and is constrained to be in the predetermined distance band at the minimum distance to the lateral edge of the coupling part 40, because there is a stable near-field intensity area at the lateral edge of the coupling part 40, and a small geometric change of the local reactance is most sensitive at this position, so that an observable amplitude and phase shaping capability can be obtained with a small change amount, without destroying the main coupling distribution at the passband center. The metal wing, the tuning slot hole and the second notch respectively change the local equivalent capacitance, the equivalent inductance or the combination of the two, to realize a directional and clear fine adjustment of the coupling strength and the phase delay, so that the coupling slope, the port return loss and the band edge isolation can be controlled simultaneously in the same structure. The design uses quantifiable geometric parameters as control variables, so that the sensitivity of the response to manufacturing tolerances and environmental drift can be engineered and managed.

[0114] In this embodiment, since the technical means of arranging the geometric control unit inside the medium and being constrained by the predetermined distance band is used, the technical problems of the prior art that the compensation unit is far away from the coupling domain, the coupling strength and the boundary are unquantifiable, the in-band and band-edge shaping are difficult to be considered, and the port return loss is difficult to be suppressed are effectively solved, and the technical effects of more controllable coupling with frequency change, lower port reflection, significantly improved directionality and isolation of the target band edge, and better production consistency are realized.

[0115] Further, in one embodiment, when the geometric control unit is a metal wing, the metal wing is arranged in the multi-layer medium body 10 and is integrally formed with the finger conductor 50 segment of the first coupling line 20 and / or the second coupling line 30, and extends in the lateral direction from the end or the side of the finger conductor 50 segment.

[0116] In this embodiment, the geometry control unit is a metal flap. The metal flap is disposed in the multilayer dielectric body 10 and is integrally formed with the finger conductor 50 segment of the first coupling line 20 and the second coupling line 30 by a same layer continuous metal pattern. The root of the flap smoothly connects with the conductor boundary of the finger conductor 50 segment, and the outer edge extends to the outside of the coupling domain in the transverse direction. The outer contour can be a rounded rectangle, a sector, or a streamlined curve to reduce the peak of the edge electric field. The thickness of the flap is consistent with the conductor layer and is composed of the same metal material as the main conductor, and is integrally solidified by a film forming and patterning step matched with the lamination process. The flap can be arranged at the end adjacent position or the side adjacent position relative to the finger conductor 50 segment to respectively emphasize the end capacitance shaping or the side capacitance shaping. The flap is insulated from the surrounding medium and is not directly conductive with other metal patterns.

[0117] When the device is working, there is a strong electric field component at the edge of the coupling part 40. The metal flap, as an integral extension of the finger conductor 50 segment, can increase the local equivalent capacitance and extend the equipotential surface within the flap coverage range, so that the coupling field is controlled to expand in the transverse direction. The flap located at the end mainly changes the phase delay and reflection characteristics at the end of the coupling segment, and the flap located at the side mainly changes the transverse distribution and frequency change slope of the coupling strength. By refining the extension length and the outer edge morphology of the flap, the change rate of the coupling degree, the echo of each port, and the directivity and port isolation of the target operating frequency band edge can be simultaneously affected when the device is in the working state.

[0118] The root of the flap needs to keep the curvature continuous geometry transition with the finger conductor 50 segment to avoid introducing additional reflections at the beginning of the flap. The extension length and the outer edge morphology determine the increment and the range of the equivalent capacitance. The greater the extension and the smoother the edge, the more conducive to obtaining smooth amplitude and phase shaping. The longitudinal position of the flap determines its focus on the in-band and the band edge: being close to the end of the coupling segment is more conducive to phase balancing and echo suppression, and being close to the middle of the coupling segment is more conducive to the refinement of the coupling slope. To maintain bidirectional consistency, the pair of flaps should be mirror arranged about the geometric center of the coupling domain; to reduce the sensitivity to process dispersion, the outer edge of the flap should use a gradual curve rather than a sharp corner.

[0119] In some optional embodiments and alternatives, the outer edge of the flap can use a circular arc, a spline, or a multi-segment smooth polyline to match different amplitude and phase shaping targets. The flap can be arranged on one side to achieve directional shaping, or can be arranged symmetrically on both sides to maintain mode balance. If a more moderate adjustment is needed, the extension length can be reduced and the round corner radius can be increased; if a stronger adjustment is needed, the flap surface area can be increased or a multi-stage extension composite profile can be introduced. The flap can be used in cooperation with a local ground window or a shielding window to further limit the field distribution and improve consistency.

[0120] In this embodiment, the metal wing formed integrally with the finger conductor 50 and extending laterally in the multilayer dielectric body 10 effectively solves the technical problems of difficult to control the edge capacitance, difficult to optimize the coupling slope and port return in the same domain, and further realizes the technical effects of smoothing the coupling degree with frequency, effectively suppressing the port return, and significantly improving the target working frequency band edge directionality and port isolation.

[0121] In another embodiment, the geometric control unit is a tuning slot or a second notch; the tuning slot is located in the multilayer dielectric body 10 and is formed on the first coupling line 20 and / or the second coupling line 30; the second notch is located in the multilayer dielectric body 10 and is formed by cutting along the edge of the first coupling line 20 and / or the second coupling line 30.

[0122] In this embodiment, the geometric control unit is a tuning slot or a second notch. The tuning slot is directly formed on the conductor pattern of the coupling line, and the slot shape can be a straight line, a broken line or a closed approximate trajectory. The slot width can be constant or slowly varying along the length direction, and the slot end can be provided with a rounded corner to reduce the current peak. The second notch is a recess formed by cutting along the edge of the coupling line or the finger conductor 50 segment. The recessed profile is smoothly connected with the original conductor boundary, and the form can be arc-shaped, trapezoidal or streamline curve. Both types of structures are formed by metal patterning process matched with the stack, located inside the multilayer dielectric body 10, and insulated from other metal layers without introducing cross-layer conduction.

[0123] When the device is working, the tuning slot extends the equivalent current path of the conductor surface and introduces a concentrated electric field at the slot gap, thereby locally producing obvious changes in equivalent inductance and capacitance, so that the coupling strength and phase delay have a adjustable range. The second notch reduces the local equivalent capacitance by narrowing the equivalent width of the edge and weakening the edge electric field strength, and changes the lateral distribution of the coupling field. Both of them can finely shape the change rate of the coupling degree when the device is in working state, and improve the return loss characteristics of each port by changing the local reactance; at the edge of the target working frequency band, both of them can improve the directionality and port isolation by changing the amplitude and phase response in place.

[0124] The length and orientation of the tuning slot determine the size and distribution of the equivalent inductance, and the slot width and slot end shape determine the concentration degree of the equivalent capacitance and the loss level. In order to obtain a smooth frequency response, the slot hole should adopt a round corner transition and introduce a slow change in the longitudinal direction. The depth and profile curvature of the second notch determine the amplitude and bandwidth of the capacitance reduction, the deeper the recess and the slower the curvature, the stronger the suppression of the band edge and the smaller the disturbance in the band. The setting position of the two should face the transverse edge of the coupling domain, so as to form efficient coupling with the edge electric field; when it is necessary to maintain mode balance, it is appropriate to be mirror image arranged in pairs. In order to avoid introducing new high-order modes or local standing waves, the boundary of the slot hole and the notch needs to keep the curvature continuous with the original conductor boundary, and a smooth transition is reserved at the junction with the lead-out section.

[0125] In some optional embodiments and alternatives, the tuning slot can adopt single-slot or multi-slot parallel, series combination form to obtain a wider shaping range; the slot hole orientation can be consistent with the signal propagation direction to emphasize phase adjustment, or it can be consistent with the transverse direction to emphasize coupling strength adjustment. The second notch can adopt single-sided recess to obtain directional shaping, or it can adopt bilateral symmetric recess to maintain mode balance. Both can be used together, first coarsely adjusted by the notch, and then finely adjusted by the slot hole, so as to realize multi-dimensional adjustment without significantly increasing the occupied area.

[0126] In this embodiment, since the technical means of directly opening a tuning slot on the conductor pattern in the multilayer medium body 10 or forming a second notch along the conductor edge and maintaining electromagnetic continuity with smooth transition are adopted, the technical problems of unquantifiable local reactance, difficult to balance in-band shaping and band edge isolation, and limited port echo suppression means in the prior art are effectively solved, and the technical effects of fine adjustment of coupling slope and phase in the same coupling domain, effective reduction of port echo, and significant improvement of target working frequency band edge directionality and port isolation are realized.

[0127] In some embodiments, the 3dB bridge includes a packaging module 1000 for carrying the multilayer medium body 10 and leading the first input end 60, the first output end 70, the second input end 80 and the second output end 90 out of the packaging module 1000.

[0128] Specifically: The packaging module 1000 of the embodiment is used to fix, protect and complete the external lead-out of the four ports of the multilayer medium body 10 of the bridge. The packaging module 1000 comprises a bearing substrate, a cavity or encapsulation structure, lead-out solder terminals and a reference ground metal. The bearing substrate can be a ceramic substrate, a metalized substrate or an organic substrate, and the surface forms a mounting area for positioning and adhesion. The multilayer medium body 10 is fixed in the mounting area of the bearing substrate by an adhesive or a low-melting solder, and the fixed surface is kept flat and parallel to the substrate reference plane to ensure the subsequent terminal coplanarity.

[0129] The first input end 60, the first output end 70, the second input end 80 and the second output end 90 on the multilayer medium body 10 are respectively electrically connected to the external solder terminals of the packaging module 1000 through short-distance metal wires or metalized vias, and each solder terminal is located at the periphery or bottom surface of the packaging module 1000, facilitating surface mounting with a circuit board. In order to maintain the stability of the electromagnetic boundary, a continuous or quasi-continuous reference ground metal is arranged inside the bearing substrate, and a ground via belt or ground ring belt is arranged around the four terminals to form a repeatable near-field environment and reduce the influence of external environmental changes on the characteristics of the bridge.

[0130] A cover or encapsulation layer can be arranged outside the packaging module 1000 to protect the internal structure. The cover has a cavity height matching the multilayer medium body 10 between the cover and the bearing substrate, and the material and thickness of the cover are selected to avoid causing obvious additional waveguide effects near the four terminals. The external solder terminals are treated with electroplated solderable surfaces, and the terminal layout follows the principle of two-by-two separation or opposite edge distribution to minimize the crosstalk and loop area between adjacent terminals. The packaging module 1000 is provided with assembly positioning marks and functional identifiers on the bottom surface, facilitating production testing and system integration.

[0131] When the device is working, signals enter the solder terminals of the packaging module 1000 from the external circuit board, and reach the corresponding ports of the multilayer medium body 10 through short-distance transition structures. The reference ground metal and the ground via belt define the electromagnetic boundary of the port area, so that the equivalent impedance of the port transition and the return current path are stable and controllable, thereby stably transmitting the coupling and phase characteristics of the bridge main body to the outside. The four ports distribute energy according to the predetermined directional relationship, and the packaging module 1000 only bears the functions of mechanical support and electrical connection, without changing the working mechanism of the bridge main body. The near-field space formed by the cavity and the cover of the packaging structure maintains the consistency of the medium and metal boundary around the coupling domain, reducing the response drift caused by external assembly differences.

[0132] In production testing and assembly process, the carrier substrate is first cleaned and surface pre-processed, the multi-layer dielectric body 10 is positioned and attached and solidified, then the metal interconnection of the terminal to the port is formed and the outer surface is processed. After the assembly of the cover or encapsulation layer, the appearance and electrical performance are retested, and the insertion loss, return loss and directivity of the four ports meet the specifications. When the system is used, the package module 1000 is welded and fixed with the circuit board by standard reflow soldering or equivalent process, and the external wiring is designed to access the four terminals according to impedance control and reference ground.

[0133] To obtain stable consistency, the transition of the four external soldering terminals to the corresponding internal ports should be as short and straight as possible and keep geometric symmetry, and smooth transition is used at the corner to suppress additional reflection. The reference ground metal is kept continuous around the terminal, and if necessary, equally spaced ground via belts are arranged on both sides of the terminal to shorten the return current path and reduce crosstalk. The adhesive material between the multi-layer dielectric body 10 and the carrier substrate is selected to have stable dielectric constant and loss, and after solidification, there should be no warping and stress concentration to ensure the terminal coplanarity and soldering reliability. The cover or encapsulation material should match the working frequency band to avoid introducing strong dielectric load; the cavity height and boundary distance should be consistent to reduce the disturbance of different batches of assembly to the near-field environment. The terminal surface treatment should consider the solderability and long-term reliability, and the terminal spacing and pad size should be tolerance controlled to ensure the assembly yield of the board level.

[0134] In some optional embodiments and alternatives, the package form can be a cavity sealing type with a ceramic cavity and a metal cover, or a mold sealing type with a substrate and an encapsulation resin, or a leadless array type with a bottom pad grid. The external soldering terminals can adopt a layout mode of four-corner distribution or opposite-side distribution, which is selected according to the system wiring direction and radio frequency isolation requirement. The internal port interconnection can adopt a combination mode of short-distance surface wiring, metalized via and inner-layer wiring, which is determined according to the layer and space constraints. If the system needs, a reference ground window or a micro transition structure for terminal electrical stability only can be added inside the package module 1000, provided that the port definition and working mechanism of the bridge body are not changed.

[0135] It should be noted that the reason for setting the package module 1000 is to provide a reproducible mechanical and electromagnetic boundary condition for the bridge and to open four ports to the system board level in the form of standardized terminals. Through the carrier and encapsulation, the bridge body is immune to direct effects of external assembly stress, pollution and environmental changes; through the structured design of the reference ground and the terminal transition, the equivalent impedance and return current path of the port area are defined, thereby reducing the response drift caused by external board material, cover, adjacent metal, etc. The unified terminal layout and size standardize the testing and mass production process, facilitating quick reuse and interchange in different systems.

[0136] In the embodiment, the technical means of carrying the multi-layer medium body 10 by the packaging module 1000 and leading the first input end 60, the first output end 70, the second input end 80 and the second output end 90 out of the packaging module 1000 are adopted, so that the technical problems of the existing technology, such as the complex bridge bare chip assembly, the sensitivity of the external environment to the port boundary condition, the inconsistent interface form, the poor consistency and the high integration cost are effectively solved, and the technical effects of the stable port transition, the simplified board-level assembly, the standardized test and mass production process, the rapid reuse in different systems and the more controllable directionality and echo performance are achieved.

[0137] The above description in the specification is only an example of the present application. Those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways without deviating from the content of the specification or exceeding the scope defined by the claims, which shall belong to the protection scope of the present application.

Claims

1. A 3dB bridge, comprising a multilayer dielectric body and a first coupling line and a second coupling line disposed on opposite layers of the multilayer dielectric body, characterized in that: The first coupling line and the second coupling line are arranged opposite each other in a wide-side overlapping manner within the coupling portion along the signal coupling direction, and the coupling portion is defined as the wide-side overlapping area of ​​the first coupling line and the second coupling line; The first coupling line and the second coupling line each branch into multiple parallel finger-shaped conductor segments at the coupling section, and adjacent finger-shaped conductor segments are staggered across layers on the normal projection plane perpendicular to the multilayer dielectric body layer to form a multi-scale coupling channel within the same coupling section. The first coupling line leads out to form a first output pin and a first input pin. The free end of the first output pin is designated as the first output terminal, and the free end of the first input pin is designated as the first input terminal. The second coupling line leads out to form a second output pin and a second input pin. The free end of the second output pin is designated as the second output terminal, and the free end of the second input pin is designated as the second input terminal. Furthermore, within the multilayer dielectric body, in the coupling region located within a predetermined distance range of the lateral edge of the coupling portion, or in the adjacent dielectric region within the multilayer dielectric body and continuous with the coupling portion, a parasitic resonant unit electromagnetically coupled to the finger conductor segment is provided to compensate for the coupling frequency characteristics of the coupling portion. Wherein, the lateral edge of the coupling part is the boundary of the coupling part in the orthogonal direction relative to the signal coupling direction; the predetermined distance range is the distance band within the multilayer dielectric body where the geometric distance d1 measured along the lateral direction with the lateral edge as the starting boundary falls into the interval [k1T,k2T], where T is the dielectric thickness of the multilayer dielectric body at the coupling part, and k1 and k2 are dimensionless coefficients greater than zero.

2. The 3dB bridge according to claim 1, characterized in that, The multiple finger-shaped conductor segments located within the coupling section include two types: long fingers and short fingers, which are arranged alternately along the signal coupling direction. The long fingers are used to dominate low-frequency coupling, and the short fingers are used to dominate high-frequency coupling. The two layers of finger-shaped conductor segments maintain a cross-layer correspondence with overlapping wide sides within the coupling section.

3. The 3dB bridge according to claim 1, characterized in that, The finger-shaped conductor segments are arranged in the lateral direction on the normal projection plane perpendicular to the multilayer dielectric body layer to form at least one finger row; the parasitic resonant unit is disposed in the multilayer dielectric body, and the geometric distance d1 measured in the lateral direction relative to the lateral edge of the coupling part satisfies d1∈[0.5T,2T].

4. The 3dB bridge according to claim 1, characterized in that, Includes a phase compensation structure; the coupling part is defined as a coupling segment along the signal coupling direction, the coupling segment being the effective coupling length region of the coupling part; the phase compensation structure is disposed at the end of the coupling segment, including a side coupling transition segment and / or an end capacitor wing and / or a first notch, to reduce the phase velocity difference between even mode and odd mode and improve directivity; Wherein, the even mode is a propagation mode in which the potentials of the first coupling line and the second coupling line are in phase, and the odd mode is a propagation mode in which the potentials of the first coupling line and the second coupling line are out of phase.

5. The 3dB bridge according to claim 1, characterized in that, It includes a packaging module, which is used to carry the multilayer media body and leads the first input terminal, the first output terminal, the second input terminal and the second output terminal out of the packaging module.

6. The 3dB bridge according to claim 1, characterized in that, The multilayer dielectric substrate is an LTCC and / or HTCC ceramic substrate.

7. The 3dB bridge according to claim 1, characterized in that, The coupling section is segmented into at least two ends along the signal coupling direction. Each segment has different finger width, finger length, finger spacing and / or effective layer spacing to form an equivalent multi-segment coupling, thereby expanding the fractional bandwidth and improving coupling flatness.

8. The 3dB bridge according to claim 1, characterized in that, The system includes a geometric control unit disposed within the multilayer dielectric body, wherein the geometric distance d2 between the geometric control unit and the lateral edge of the coupling portion is within the predetermined distance range; the geometric control unit is configured to adjust the rate of change of the coupling degree of the coupling portion with frequency, the echo of the first input terminal / first output terminal / second input terminal / second output terminal, and the port isolation of the target operating frequency band edge when the 3dB bridge is in operation; the geometric control unit is a metal fin, a tuning slot, or a second notch; wherein the geometric distance d2 is the minimum geometric distance in the lateral direction between the geometric control unit and the lateral edge of the coupling portion, and d2∈[k1·T,k2·T].

9. The 3dB bridge according to claim 8, characterized in that, The geometric control unit is a metal wing, which is disposed in the multilayer dielectric body and integrally formed with the finger-shaped conductor segment of the first coupling line and / or the second coupling line, and extends laterally from the end or side of the finger-shaped conductor segment.

10. The 3dB bridge according to claim 8, characterized in that, The geometric control unit is a tuning slot or a second notch; the tuning slot is located within the multilayer dielectric body and is formed on the first coupling line and / or the second coupling line; the second notch is located within the multilayer dielectric body and is formed by cutting along the edge of the first coupling line and / or the second coupling line.

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