Coupler based on dielectric integrated suspended parallel strip line and communication device

Abstract

The application discloses a coupler based on a dielectric integrated suspended parallel strip line and a communication device, and relates to the technical field of microwave transmission. The coupler comprises a dielectric integrated suspended line platform, a differential coupler circuit and a defective metal ridge structure. The defective metal ridge structure is arranged between the upper and lower signal guide strips. The structure is coupled with the guide strips to generate resonance under common mode signal excitation, thereby effectively suppressing the common mode signal. Meanwhile, the overall size of the differential coupler is reduced through spatial multiplexing on the structure. In addition, the dielectric integrated suspended line platform is provided with an electromagnetic shielding cavity, and the differential coupler circuit is suspended in an air cavity in the electromagnetic shielding cavity, thereby effectively reducing dielectric loss and radiation loss and improving signal transmission efficiency.

Description

Technical Field

[0001] This application relates to the technical field of microwave transmission, and more particularly to a coupler and communication device based on a dielectric integrated suspended parallel stripline. Background Technology

[0002] With the rapid development of radio frequency (RF) circuits and wireless communication systems, higher demands are being placed on higher frequencies, faster data transmission rates, and better signal integrity. Compared to single-ended circuits, differential circuits offer better suppression of ambient noise, reduction of crosstalk, and immunity to electromagnetic interference, thus attracting increasing attention. Branch-line couplers are one of the most fundamental components in RF / microwave systems, providing the required equal / unequal power distribution and a specific phase difference between the two output ports. They are widely used in power amplifiers, phase shifters, antenna arrays, and other RF front-end circuits.

[0003] Therefore, couplers with differential functionality play a crucial role in fully differential RF front-end systems. Double-sided parallel striplines are a commonly used type of balanced transmission line. Their traditional structure includes a dielectric substrate and two signal conductors on either side. However, due to planar layout limitations, their common-mode rejection is typically poor, and they are prone to radiation loss when exposed to air, posing challenges to signal integrity and packaging efficiency. Summary of the Invention

[0004] The main objective of this application is to provide a coupler and communication device based on a dielectric integrated suspended parallel stripline, which aims to solve the technical problems of poor common-mode rejection capability, high radiation loss, and unfavorable system integration and packaging of traditional balanced transmission line structures.

[0005] To achieve the above objectives, this application proposes a coupler based on a dielectric-integrated suspended parallel stripline, comprising:

[0006] The dielectric integrated suspension line platform has an electromagnetic shielding cavity and an air cavity located within the electromagnetic shielding cavity;

[0007] A differential coupler circuit, suspended within the air cavity, includes a first signal guide band and a second signal guide band arranged vertically opposite to each other, the first signal guide band and the second signal guide band forming a balanced transmission line structure;

[0008] A defective metal ridge structure is disposed between the first signal conductor and the second signal conductor;

[0009] The defective metal ridge structure is used to couple with the first signal conduction band and the second signal conduction band to generate resonance under common-mode signal excitation, so as to suppress the common-mode signal.

[0010] In one embodiment, the dielectric integrated suspension line platform includes six dielectric boards S1~S6 stacked from top to bottom and an array of metallized vias penetrating each dielectric board, wherein the upper and lower surfaces of each dielectric board are coated with copper to form a metal layer.

[0011] The metal layer on the upper surface of the dielectric substrate S1, the metal layer on the lower surface of the dielectric substrate S6, and the metallized through-hole array form an electromagnetic shielding cavity.

[0012] A first air cavity is formed by hollowing out the middle of the dielectric plate S2 and its upper and lower metal layers, and a second air cavity is formed by hollowing out the middle of the dielectric plate S5 and its upper and lower metal layers.

[0013] The first signal conduction band and the second signal conduction band are respectively etched on the metal layer on the upper surface of the dielectric substrate S3 and the metal layer on the lower surface of the dielectric substrate S4;

[0014] The defective metal ridge structure is etched on the metal layer on the lower surface of the dielectric substrate S3 and the metal layer on the upper surface of the dielectric substrate S4.

[0015] In one embodiment, the defective metal ridge structure includes:

[0016] Multiple defective metal ridges are arranged parallel to and opposite to the first signal conduction band and the second signal conduction band, and are used to couple with the first signal conduction band and the second signal conduction band to form an LC resonant circuit under common-mode signal excitation, so as to generate resonance at the target resonant frequency.

[0017] The length of the defective metal ridge is set to match the target resonant frequency.

[0018] In one embodiment, the defective metal ridge structure is structurally symmetrical with respect to the first signal conduction band and with respect to the second signal conduction band, such that the potential of the defective metal ridge is 0V under differential mode signal excitation.

[0019] In one embodiment, the input / output port of the first signal conductor is led out along a first direction, and the input / output port of the second signal conductor is led out along a second direction perpendicular to the first direction.

[0020] In one embodiment, the metallized via array includes multiple rows of vias arranged along the first direction and the second direction;

[0021] Specifically, in the region corresponding to the first signal conductor input / output port, the via has a first lead-out notch at the dielectric substrate S3 and its upper and lower metal layers; in the region corresponding to the second signal conductor input / output port, the via has a second lead-out notch at the dielectric substrate S4 and its upper and lower metal layers.

[0022] In one embodiment, the differential coupler circuit is a branch-line coupler with four transmission branches, and each defective metal ridge is configured to correspond to one transmission branch of the differential coupler circuit.

[0023] In one embodiment, the dielectric substrate S3 and the dielectric substrate S4 are hollowed out in areas not covered by the first signal conductor, the second signal conductor, and the defective metal ridge.

[0024] In one embodiment, the thickness of dielectric substrate S1, dielectric substrate S2, dielectric substrate S5 and dielectric substrate S6 along the stacking direction is h1, and the thickness of dielectric substrate S3 and dielectric substrate S4 along the stacking direction is h2, wherein h1>h2.

[0025] In addition, to achieve the above objectives, this application also proposes a communication device, including the aforementioned coupler based on a medium-integrated suspended parallel stripline.

[0026] One or more technical solutions proposed in this application have at least the following technical effects:

[0027] This application proposes a coupler based on a dielectric-integrated suspended parallel stripline, comprising a dielectric-integrated suspended line platform, a differential coupler circuit, and a defective metal ridge structure. The defective metal ridge structure is placed between the upper and lower signal conduction bands. This structure resonates with the conduction bands under common-mode signal excitation, effectively suppressing common-mode signals. While achieving common-mode suppression, the overall size of the differential coupler is reduced through spatial multiplexing in the structure. Furthermore, the dielectric-integrated suspended line platform has an electromagnetic shielding cavity, and the differential coupler circuit is suspended in an air cavity within the electromagnetic shielding cavity, effectively reducing dielectric loss and radiation loss, and improving signal transmission efficiency. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the layered structure of an embodiment of a coupler based on a dielectric integrated suspended parallel stripline according to this application;

[0031] Figure 2This is a schematic diagram of the layered structure of a second embodiment of a coupler based on a dielectric integrated suspended parallel stripline according to this application;

[0032] Figure 3 This is a schematic diagram of the structural parameters of the metal layer G5 according to an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the structural parameters of the metal layer G6 according to an embodiment of this application;

[0034] Figure 5 This is a simulation result diagram of scattering parameters during differential mode signal transmission according to an embodiment of this application;

[0035] Figure 6 This is a simulation result of the phase difference during differential signal transmission according to an embodiment of this application;

[0036] Figure 7 This is a diagram showing the common-mode suppression results of an embodiment of this application;

[0037] Figure 8 This is a diagram showing the cross-mode suppression result of an embodiment of this application.

[0038] Reference numerals: 01, dielectric integrated suspension line platform, 11, metallized via array, 12, first lead-out notch, 14, air cavity, 02, differential coupler circuit, 21, first signal conductor, 22, second signal conductor, 03, defective metal ridge structure, 31, defective metal ridge.

[0039] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0041] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0042] With the rapid development of radio frequency (RF) circuits and wireless communication systems, the demand for higher frequencies, faster data transmission rates, and better signal integrity is increasing. Against this backdrop, differential circuits have gained widespread attention due to their advantages in suppressing environmental noise, reducing crosstalk, and resisting electromagnetic interference, becoming an important choice for realizing high-performance RF systems. As one of the fundamental components of RF and microwave systems, branch-line couplers can achieve equal or unequal power distribution and generate a specific phase difference between output ports, thus being widely used in power amplifiers, phase shifters, antenna arrays, and other RF front-end circuits. Therefore, couplers with differential functionality play a crucial role in constructing fully differential RF front-end systems.

[0043] In differential circuit design, double-sided parallel stripline is a commonly used balanced transmission line structure. Its traditional form consists of a single dielectric substrate and two signal conductors distributed on both sides. However, limited by planar layout, this structure often has limited common-mode rejection capability, and because the conductors are exposed to air, they are prone to radiation loss, thus affecting signal integrity and limiting system packaging efficiency. To solve these problems, three-dimensional heterogeneous integration technology has been introduced. By vertically integrating shielding layers, grounding structures, or functional modules between multiple dielectric layers, it can not only effectively enhance common-mode noise rejection but also reduce radiation loss, while achieving a more compact packaging layout. This provides a high-performance, high-reliability integrated solution for fully differential RF front-end systems.

[0044] To address the shortcomings of existing differential couplers in terms of common-mode suppression and structural compactness, this invention proposes a coupler based on a dielectric integrated suspended parallel stripline, comprising: a dielectric integrated suspended stripline platform 01, which internally forms an electromagnetic shielding cavity and an air cavity 14 located within the electromagnetic shielding cavity; a differential coupler circuit 02, suspended within the air cavity 14, including a first signal conductor 21 and a second signal conductor 22 arranged vertically opposite each other, the first signal conductor 21 and the second signal conductor 22 forming a balanced transmission line structure; and a defective metal ridge structure 03 disposed between the first signal conductor 21 and the second signal conductor 22; wherein, the defective metal ridge structure 03 is used to couple with the first signal conductor 21 and the second signal conductor 22 to generate resonance under common-mode signal excitation, thereby suppressing the common-mode signal.

[0045] This invention provides a coupler based on a dielectric integrated suspended parallel stripline, comprising three parts: a dielectric integrated suspended line platform 01, a differential coupler circuit 02, and a defective metal ridge structure 03. The dielectric integrated suspended line platform 01 (SISL) is a multilayer planar circuit structure composed of alternating layers of dielectric substrates and metal layers. Inside the platform, a shielded electromagnetic cavity surrounded by metal walls is formed by patterning specific metal layers and hollowing out the dielectric substrate. An air cavity 14 is further formed within the shielded cavity, constructed by removing a portion of the dielectric material. This platform structure encloses the main circuit body within the metal cavity, blocking the external radiation path of electromagnetic energy, thereby eliminating the radiation loss of traditional open or semi-open balanced transmission line structures. Simultaneously, the air cavity 14 replaces most of the solid dielectric, reducing dielectric loss caused by dielectric polarization relaxation. These two factors work together to reduce the overall transmission loss of the coupler.

[0046] like Figure 1As shown, the differential coupler circuit 02 is suspended within the aforementioned air cavity 14. The transmission line structure of this circuit is a Double-Sided Parallel-Strip Line (DSPSL). The DSPSL includes a first signal conductor 21 and a second signal conductor 22 arranged parallel to each other, forming a differential transmission structure. Under differential signal excitation, the current amplitudes carried on the two conductors are equal and their phases are opposite. The electric field energy is mainly concentrated in the dielectric region between the two conductors and within the nearby air cavity 14. The DSPSL structure itself has inherent common-mode rejection characteristics and is easy to achieve high characteristic impedance, facilitating connection with other circuits. In this invention, the DSPSL is embedded inside the air cavity 14 of the SISL platform. This combined structure can be called a Substrate Integrated Suspended Parallel-Strip Line (ISPSL). The ISPSL can form a self-encapsulating structure, solving the problem of high radiation loss and the need for an additional metal shielding box caused by traditional DSPSLs exposed to air.

[0047] like Figure 3 As shown, the defective metal ridge structure 33 is disposed inside the dielectric substrate between the first signal conduction band 21 and the second signal conduction band 22, i.e., integrated into the dielectric substrate of the aforementioned SISPSL. In differential signal mode, since the potentials of the two signal conduction bands cancel each other out at the center plane, forming a virtual electric wall, the electric field at the location of the defective metal ridge 31 is very weak. Therefore, this structure has little impact on the transmission of differential signals, maintaining the original differential performance of the coupler. Under common-mode signal excitation, the first signal conduction band 21 and the second signal conduction band 22 have the same potential, and a strong electric field coupling is formed between them and the defective metal ridge 31. The defective metal ridge 31, together with the upper and lower conduction bands and its own capacitance to ground, constitutes a resonant unit. When the common-mode signal frequency is close to the resonant frequency of this unit, a strong coupling is generated between the defective metal ridge 31 and the conduction band, which is blocked by resonant reflection, thereby generating a strong common-mode signal suppression effect near that frequency point. By setting multiple defective metal ridges 31 of different sizes, multiple resonant points can be introduced. These resonant points merge with each other, which can expand the bandwidth of common-mode suppression.

[0048] This application achieves functional integration and space reuse. The defective metal ridge 31 is embedded inside the SISPSL dielectric substrate carrying the differential conduction band, eliminating the need for additional circuit layout area as required by cascaded common-mode rejection filters. The SISL platform provides electromagnetic shielding and a low-loss environment, while its multi-layered structure naturally enables three-dimensional encapsulation of the circuit. This design allows the SISPSL-based differential coupler to achieve low transmission loss, high common-mode rejection capability, and simultaneously achieve miniaturization and high integration.

[0049] In one embodiment, such as Figure 2 As shown, the dielectric integrated suspension line platform 01 includes six dielectric boards S1~S6 stacked from top to bottom and a metallized through-hole array 11 penetrating each dielectric board. The upper and lower surfaces of each dielectric board are coated with copper to form a metal layer.

[0050] The metal layer on the upper surface of dielectric substrate S1, the metal layer on the lower surface of dielectric substrate S6, and the metallized via array 11 form an electromagnetic shielding cavity; a first air cavity is formed by hollowing out the middle of dielectric substrate S2 and its upper and lower metal layers, and a second air cavity is formed by hollowing out the middle of dielectric substrate S5 and its upper and lower metal layers; the first signal guide band 21 and the second signal guide band 22 are respectively etched on the metal layer on the upper surface of dielectric substrate S3 and the metal layer on the lower surface of dielectric substrate S4; the defect metal ridge structure 03 is etched on the metal layer on the lower surface of dielectric substrate S3 and the metal layer on the upper surface of dielectric substrate S4.

[0051] In one specific embodiment, the dielectric integrated suspension line platform 01 adopts a stacked structure of six dielectric PCBs and twelve metal layers. From top to bottom, the six dielectric PCBs are labeled S1, S2, S3, S4, S5, and S6. Each dielectric PCB has copper plating on both its upper and lower surfaces to form a metal layer, totaling twelve metal layers, labeled G1 to G12 from top to bottom. A periodically arranged array of metallized vias 11 penetrates all the dielectric PCBs and metal layers.

[0052] Metal layer G1, metal layer G12, and the metallized via array 11 together constitute a complete metal shielding cavity. Metal layer G1 serves as the top cover, metal layer G12 as the bottom cover, and the metallized via array 11 as the sidewalls, enclosing the entire internal circuit structure to form an electromagnetic shielding cavity. This effectively prevents the outward radiation of electromagnetic energy from the internal circuit and shields the internal circuit from external electromagnetic interference, thereby reducing radiation loss and improving electromagnetic compatibility.

[0053] The dielectric substrate S2 and its upper and lower surface metal layers G3 and G4 are hollowed out in the middle region to form a first air cavity. The dielectric substrate S5 and its upper and lower surface metal layers G9 and G10 are also hollowed out in the middle region to form a second air cavity. These two air cavities are symmetrically distributed vertically and are filled with air. The dielectric constant of air is much lower than that of solid dielectric materials; therefore, the presence of the air cavity 14 significantly reduces the equivalent dielectric constant along the signal transmission path, thereby reducing dielectric loss caused by dielectric material polarization. The air cavity structure is a key feature for achieving low transmission loss in the SISL platform.

[0054] The transmission line portion of the differential coupler circuit 02 consists of metal layers G5 and G8. Metal layer G5 is located on the upper surface of dielectric substrate S3, serving as the first signal conduction band 21. Metal layer G8 is located on the lower surface of dielectric substrate S4, serving as the second signal conduction band 22. These two metal conduction bands are parallel to each other, separated by the lower half of dielectric substrate S3, the upper half of dielectric substrate S4, and the bonding layer between them, forming a double-sided parallel stripline structure. In differential operating mode, signals are transmitted from G5 and G8 with equal amplitude and opposite phase, and their electric field energy is mainly confined to the region between the two conduction bands. This structure itself has balanced characteristics and is easy to design and implement the required odd-mode characteristic impedance.

[0055] The defective metal ridge structure 03 consists of metal layers G6 and G7. Metal layer G6 is located on the lower surface of dielectric substrate S3, and metal layer G7 is located on the upper surface of dielectric substrate S4. G6 and G7 are patterned into specific strip or block patterns, separated from the adjacent metal layers G5 and G8 by portions of the dielectric of dielectric substrates S3 and S4, and the edges of the patterns of G6 and G7 are isolated from the surrounding metal ground (such as G4 and G9). This structure is embedded between the two signal conductions of the DSPSL. During differential signal transmission, since the center plane between G5 and G8 is approximately an electric wall, the electric field at this location is very weak, resulting in extremely low induced voltages on G6 and G7, which have little impact on the propagation of differential signals. Under common-mode signal excitation, G5 and G8 have the same potential, forming a strong capacitive coupling with G6 and G7. The defective metal ridge structure 03 of G6 and G7, the coupling capacitance between the upper and lower signal conductions, and the parasitic capacitance to the surrounding metal ground together constitute the resonant circuit. When the frequency of the common-mode signal approaches the resonant frequency of these resonant circuits, energy coupling and reflection occur, resulting in significant common-mode signal suppression near that frequency. By designing the pattern size of the defective metal ridge structure 03, multiple resonant frequency points can be independently adjusted, thereby broadening the bandwidth of common-mode suppression.

[0056] Metal layers G2 and G11, serving as the primary internal grounding layers, are tightly connected to the metallized vias, jointly enhancing the integrity of the shielding cavity and providing a stable reference ground plane for the internal circuitry. Metal layers G3, G4, G9, and G10, in addition to forming the boundary of the air cavity 14, also serve as internal grounding layers, helping to maintain the electromagnetic field distribution and suppress unwanted modes.

[0057] In this embodiment, the outer conductor shielding cavity is formed by metal layers G2 and G11 and the metallized via array 11; the differential transmission line circuit of the inner conductor is formed by metal layers G5 and G8; and the embedded common-mode rejection resonant structure is formed by metal layers G6 and G7. The entire structure is manufactured in an integrated manner using a multilayer PCB process, effectively combining the low loss and self-packaging characteristics of the SISL platform, the balanced transmission characteristics of the DSPSL, and the broadband common-mode rejection characteristics of the defective metal ridge 31. This integrated design ensures circuit performance while avoiding the use of an external shielding box and maximizing the saving of the planar layout area of ​​the circuit board.

[0058] In one embodiment, the defective metal ridge structure 03 includes:

[0059] Multiple defective metal ridges 31 are arranged parallel to and opposite to the first signal conduction band 21 and the second signal conduction band 22, and are used to couple with the first signal conduction band 21 and the second signal conduction band 22 to form an LC resonant circuit under common-mode signal excitation, so as to generate resonance at the target resonant frequency; wherein, the length of the defective metal ridge 31 is matched with the target resonant frequency.

[0060] This can be understood as follows: under common-mode signal excitation, the first signal conduction band 21 and the second signal conduction band 22 are at the same potential. At this time, each defective metal ridge 31 unit forms a coupling capacitor with the signal conduction bands above and below it through a dielectric substrate. Simultaneously, the metal strip structure of each defective metal ridge 31 unit exhibits equivalent inductance characteristics. This equivalent inductance, together with the aforementioned coupling capacitor, constitutes an LC resonant circuit. When the frequency of the input common-mode signal matches the inherent resonant frequency of this LC circuit, the circuit resonates. At the resonant frequency, the coupling between the defective metal ridge 31 unit and the signal conduction band is enhanced, causing most of the common-mode signal energy to be reflected or absorbed by the resonant structure, thereby generating a strong common-mode signal suppression effect at that specific frequency.

[0061] The length of the defective metal ridge 31 unit is a key physical parameter that determines its equivalent inductance and thus controls its resonant frequency. By designing the length of each defective metal ridge 31 unit, its resonant frequency can be matched with the target frequency of the common-mode signal that needs to be suppressed. Specifically, increasing the length of the metal ridge increases its equivalent inductance, resulting in a lower resonant frequency; conversely, shortening the length decreases the equivalent inductance, resulting in a higher resonant frequency.

[0062] Specifically, see the attached document. Figure 4The schematic diagram of metal layer G6 shown includes a cavity region and four defective metal ridges 31 distributed around the cavity. These four defective metal ridges 31 have similar structural outlines, differing mainly in the length of their respective slots. When the differential coupler transmits a common-mode signal, metal layers G5 and G8 are at the same high potential, while the central cavity region, connected to the surrounding grounded metal layer, maintains a zero potential and can serve as an effective ground reference. In this state, coupling capacitance is formed between the high-potential metal layers G5 and G8 and each defective metal ridge 31. Simultaneously, each defective metal ridge 31 itself constitutes an inductive path. Therefore, for each defective metal ridge 31, an LC resonant circuit is formed between it, the upper and lower signal conduction bands, and ground. When the common-mode signal frequency reaches the resonant frequency of the LC circuit corresponding to a certain defective metal ridge 31, the circuit resonates. At the resonant point, the input impedance from the signal conductor to the defective metal ridge 31 theoretically approaches zero or a minimum value, causing the common-mode signal at that frequency to be short-circuited to ground or to undergo total reflection, thus preventing it from being transmitted forward through the coupler.

[0063] By setting multiple defective metal ridges 31 with different slot lengths, i.e., different resonant frequencies, common-mode rejection can be generated at multiple discrete frequency points. By rationally designing the distribution of these resonant frequency points, making them close to or partially overlapping each other, effective common-mode rejection can be achieved over a wider frequency range, thereby expanding the common-mode rejection bandwidth. Furthermore, the resonant characteristics of each defective metal ridge 31 can be independently adjusted, providing flexibility for optimizing the common-mode rejection response of the coupler. This method of integrating multiple tunable resonant units within the dielectric substrate inside the transmission line achieves broadband common-mode rejection without increasing the planar size of the circuit, achieving a high degree of integration of function and structure.

[0064] In one embodiment, the defective metal ridge structure 31 is structurally symmetrical with respect to the first signal conduction band 21 and with respect to the second signal conduction band 22, such that the potential of the defective metal ridge 31 is 0V under differential mode signal excitation.

[0065] In this embodiment, the defective metal ridge structure 03 is physically symmetrical about the central plane between the first signal conductor 21 and the second signal conductor 22. Specifically, the defective metal ridge structure 03 is precisely positioned within this central plane, and its dielectric thickness with the upper first signal conductor 21 and its dielectric thickness with the lower second signal conductor 22 are equal.

[0066] When the differential coupler transmits a differential-mode signal, the current amplitudes carried on the first signal conductor 21 and the second signal conductor 22 are equal, but their phases differ by 180 degrees. According to electromagnetic field theory, the tangential component of the electric field is zero on the central plane between two parallel and anti-phase excited conductors, and this plane constitutes an ideal electric wall or virtual ground plane. Since the defective metal ridge structure 03 is symmetrically placed within this central plane, it is located on this virtual ground plane. Therefore, under differential-mode signal excitation, the electric field strength at the location of the defective metal ridge structure 03 is theoretically zero, resulting in an induced potential of zero volts on its metal body.

[0067] Specifically, in the stacked structure embodiment, when a positive potential is applied to metal layer G5 (first signal conduction band 21) and an equal-amplitude negative potential is applied to metal layer G8 (second signal conduction band 22), the electric fields generated by G5 and G8 cancel each other out at the spatial location of the defective metal ridge structure 03 composed of metal layers G6 and G7. This makes the net induced charge on metal layers G6 and G7 zero, and their potential remains at the same zero potential as the surrounding ground reference point. Therefore, in differential mode, the defective metal ridge structure 03 is equivalent to a ground plane node with a fixed potential located inside the transmission line.

[0068] Since the defective metal ridge 31 has a zero potential under differential mode signal, there is no time-varying potential difference between it and the upper and lower signal conduction bands. This results in the coupling capacitance between the defective metal ridge 31 and the signal conduction bands not being excited during differential mode signal transmission, and no energy exchange occurring. Therefore, the defective metal ridge structure 03 has no substantial impact on the propagation characteristics of the differential mode signal, including its characteristic impedance, phase velocity, and insertion loss. The energy of the differential mode signal is completely confined to the main coupling region between the first and second signal conduction bands 22, and its transmission behavior is consistent with that of a standard double-sided parallel stripline without the defective metal ridge structure 03.

[0069] This symmetrical design ensures the selective operation of the defective metal ridge structure 03, generating strong resonant coupling and suppression only for common-mode signals, while having no effect on differential-mode signals. This characteristic allows the coupler to effectively suppress common-mode noise and improve the common-mode rejection ratio while fully preserving and transmitting useful differential signals, ensuring the normal operation of the differential circuit. Furthermore, since the differential-mode signal is unaffected, this common-mode rejection function does not require sacrificing the bandwidth of the differential signal or increasing its insertion loss, achieving decoupling and independent optimization of common-mode rejection and differential-mode transmission performance. Specifically, when the differential coupler is transmitting differential-mode signals, assuming metal layer G5 is at a positive potential and metal layer G8 is at a negative potential, then metal layers G6 and G7 are at zero potential and can be considered as a virtual ground plane. That is, the presence of the defective metal ridge 31 will not affect the transmission of differential-mode signals.

[0070] In one embodiment, the input / output port of the first signal guide 21 is led out along a first direction, and the input / output port of the second signal guide 22 is led out along a second direction perpendicular to the first direction.

[0071] Specifically, see the attached document. Figure 3 The schematic diagram of the metal layer G5 shows a branch-line coupler with four ports. When all ports are terminated with matched loads, the signal power input from port 1 is evenly distributed to the outputs of ports 2 and 3, with a fixed 90-degree phase difference between the output signals of ports 2 and 3. Port 4, ideally, has no power output and is defined as an isolation port. Due to the high geometric symmetry of this branch-line coupler structure, its four ports are electrically equivalent. Any port can be used as an input port. In this case, one of the two adjacent ports located on the same side of the rectangle as the input port becomes the isolation port, while the two ports located on the opposite side of the input port become the output ports, maintaining equal power distribution and a 90-degree phase difference.

[0072] The performance of the branch line coupler is determined by two sets of key dimensional parameters: the length and width of the first set of branch lines are denoted as l. r1 With w r1 The length and width of the second group of branch lines are denoted as l. r2 With w r2 These dimensions directly determine the characteristic impedance, power distribution ratio, and phase relationship of the coupler at the center frequency. Furthermore, the length and width of the rectangular region occupied by the coupler's metallic pattern are denoted as l. cav With w cav This region is related to the size of the lower air cavity. The branch-line coupler on the first signal conductor 21 (metal layer G5) has its four input / output port connection lines extending and leading out along a first direction, such as the x-direction. The branch-line coupler on the second signal conductor 22 (metal layer G8) has its four input / output port connection lines extending and leading out along a second direction perpendicular to the first direction, such as the y-direction. This means that the port orientation of the upper and lower coupler circuits is rotated by 90 degrees.

[0073] This orthogonal port layout design allows the first signal guide 21 and the second signal guide 22 to overlap spatially without any planar projection conflict in their port connections. This allows the upper and lower circuit layers to be tightly stacked vertically, sharing the same planar projection area, thus saving planar layout area on the circuit board and achieving three-dimensional integration. Simultaneously, because the upper and lower circuit layers are isolated by a dielectric substrate, they are electrically independent, processing the positive and negative signals of the differential signal pair separately. The orthogonal port design facilitates vertical interconnection or planar routing with external differential interfaces or adjacent circuit modules, improving the flexibility of circuit integration and routing freedom.

[0074] In one embodiment, the metallized via array 11 includes multiple rows of vias arranged along the first direction and the second direction; wherein, in the region corresponding to the input / output port of the first signal conductor 21, the vias are provided with a first lead-out notch 12 at the dielectric substrate S3 and its upper and lower metal layers; in the region corresponding to the input / output port of the second signal conductor 22, the vias are provided with a second lead-out notch at the dielectric substrate S4 and its upper and lower metal layers.

[0075] In this embodiment, the metallized via array 11 is composed of multiple rows of metallized vias arranged regularly along the first and second directions. These vias penetrate all dielectric plates and metal layers of the entire dielectric integrated suspension line platform 01, forming a continuous metal sidewall surrounding the internal circuit area, thus constituting an electromagnetic shielding cavity.

[0076] In the region corresponding to the input / output port of the first signal conductor 21, the metallized via array 11 provides a first lead-out notch 12 at the dielectric substrate S3 and its adjacent metal layers above and below. Specifically, in this local region, specific opening or interruption patterns are pre-designed and manufactured in the dielectric substrate S3 layer, the metal layer G5 above it, and the metal layer G6 below it, so that the metallized via pillars at this location are cut off or removed. This notch provides a physical channel for the port connection line of the first signal conductor 21 etched on the metal layer G5, allowing it to pass through the sidewall of the closed shielding cavity formed by the metallized via array 11 and extend to the external circuit area without short-circuiting with the via pillars that serve as the sidewall of the shielding cavity.

[0077] Similarly, in the region corresponding to the input / output port of the second signal conductor 22, the metallized via array 11 has a second lead-out notch at the dielectric substrate S4 and its adjacent metal layers above and below. Specifically, in this local region, specific opening or interruption patterns are pre-designed and manufactured in the dielectric substrate S4 layer, the metal layer G7 above it, and the metal layer G8 below it, so that the metallized via pillars at this location are cut off or removed. This notch provides a physical channel for the port connection line of the second signal conductor 22 etched on the metal layer G8, allowing it to pass through the other side wall of the shielded cavity and extend to the external circuit area.

[0078] The first lead-out notch 12 and the second lead-out notch are spatially offset. Since the first signal guide 21 port leads out along a first direction, while the second signal guide 22 port leads out along a second direction perpendicular to it, these two notches are located at two different positions on the sidewall of the shielding cavity. This offset design allows the ports of the upper and lower signal lines to lead out independently from different sides, avoiding intersections and interference between port traces in the planar or vertical direction. By setting these structured lead-out notches, the shielding cavity formed by the metallized via array 11 maintains complete continuity in most areas, ensuring electromagnetic shielding effectiveness. Local openings are only made at necessary port lead-out locations to allow signal lines to pass through. This design solves the physical connection problem between internal circuits and external interconnections while maintaining overall shielding integrity. The dimensions of the notch area are precisely designed to minimize the opening size while ensuring smooth signal line passage, thereby reducing potential electromagnetic leakage. This method is an effective technical means to achieve external lead design in the self-encapsulated structure of the SISL platform.

[0079] In one embodiment, the differential coupler circuit 02 is a branch-line coupler with four transmission branches, and each of the defective metal ridges 31 is configured to correspond to one transmission branch of the differential coupler circuit 02.

[0080] Specifically, see the attached document. Figure 3 With appendix Figure 4 The branch line coupler consists of two sets of transmission branches. The length and width of the first set of branches are l and l, respectively. r1 With w r1 The length and width of the second group of branches are l and l respectively. r2 With w r2 The rectangular region occupied by the coupler's metal pattern, i.e., the cavity region, has a length and width of l. cav With w cav .

[0081] The basic outline of each defective metal ridge 31 unit is rectangular, with a length of l. in Width is w inOne corner of the rectangle is cut off, with the length of the cut right-angled side being q. This chamfer is designed to adjust the current distribution at the edge of the metal ridge to fine-tune its equivalent inductance. A rectangular slot is provided in the central region of each defective metal ridge 31 element. The distance between this slot and the outer edge of the metal ridge element is g, and the width of the slot itself is s. The structural outline and dimensions l of the four defective metal ridge 31 elements are shown. in w in q, g, and s are all kept constant; the only difference between them is the length of their respective rectangular slots, denoted as l. c1 l c2 l c3 With l c4 The defective metal ridge structure 03 on metal layer G6 and metal layer G7 is the same, both containing four units with the above-mentioned characteristics.

[0082] Under differential-mode signal excitation, the potentials of metal layers G5 and G8 are out of phase, while metal layers G6 and G7 are at virtual ground potential. At this time, the defective metal ridge 31 unit acts as a zero-potential node, with no time-varying electric field coupling between it and the upper and lower signal conduction bands, thus not affecting the transmission characteristics of the differential-mode signal. Under common-mode signal excitation, the potentials of metal layers G5 and G8 are the same, and the cavity region is at zero potential. At this time, each defective metal ridge 31 unit forms an electric field coupling with the upper and lower metal layers G5 and G8, generating an equivalent coupling capacitance. Simultaneously, current flows through the metal path of each defective metal ridge 31 unit, and this path exhibits equivalent inductance characteristics. The coupling capacitance and equivalent inductance constitute an LC resonant circuit. When the common-mode signal frequency coincides with the resonant frequency of this LC circuit, the circuit resonates, and the input impedance from the signal conduction band to the defective metal ridge 31 decreases sharply, causing the common-mode signal energy at that frequency to be strongly reflected or absorbed.

[0083] The length l of the rectangular groove c This is a key parameter for adjusting the equivalent inductance value of each defective metal ridge unit (31 units). Changes in slot length directly alter the effective current flow path length and shape within the metal ridge. Increasing the slot length l... c This forces the current to take a longer path, thus increasing the equivalent inductance of the unit; conversely, it reduces l. c This will shorten the current path and reduce the equivalent inductance. According to the LC resonant frequency formula f... res = 1 / (2π With the coupling capacitance C relatively fixed, the slot length l of the four defective metal ridge 31 units can be adjusted independently. c1 To l c4 It allows for precise setting of the different resonant frequencies of the four LC resonant circuits.

[0084] By placing four defective metal ridge units 31 near the four transmission branches of the branch-line coupler, the common-mode signal can be coupled to these four resonant units simultaneously during transmission within the coupler. This is achieved through the design of l c1 To l c4 The values ​​are adjusted to ensure that the four resonant frequencies are reasonably distributed within a target frequency band. When the common-mode signal frequency falls into this band, one or more defective metal ridge elements will always operate near their resonant frequencies, resulting in effective common-mode suppression. The superposition effect of multiple discrete resonant peaks can form a flat and deep common-mode suppression band over a wider frequency range, thereby extending the common-mode suppression bandwidth of the differential coupler. This design achieves broadband suppression of common-mode noise without interfering with the differential-mode signal performance.

[0085] In one embodiment, the dielectric substrate S3 and the dielectric substrate S4 are hollowed out in areas not covered by the first signal guide 21, the second signal guide 22 and the defective metal ridge 31.

[0086] Specifically, in one embodiment, dielectric plates S3 and S4 have a portion of their dielectric material selectively removed in specific areas. Specifically, on dielectric plate S3, the dielectric material is hollowed out in the area excluding the area carrying the first signal conductor pattern 21, the defective metal ridge structure 03, and the necessary support structure. Similarly, on dielectric plate S4, the dielectric material is also hollowed out in the area excluding the area carrying the second signal conductor pattern 22, the defective metal ridge structure 03, and the necessary support structure. This hollowing-out operation forms air cavities 14 located inside dielectric plates S3 and S4. These air cavities 14 are adjacent to or partially overlap with the first and second air cavities formed by dielectric plates S2 and S5 in the vertical direction. Through this design, the effective dielectric constant of the signal transmission path, particularly the area between the first signal conductor 21 and the second signal conductor 22, and the area around the defective metal ridge structure 03, is further reduced. This is because more solid dielectric is replaced by air, which has a dielectric constant close to 1. The loss tangent of solid dielectric materials is typically higher than that of air. Reducing the volume of the solid dielectric around the signal path means reducing energy dissipation caused by dielectric polarization relaxation and conductivity losses. Therefore, hollowing out the blank areas in dielectric substrates S3 and S4 can effectively reduce the dielectric loss of the entire differential coupler when transmitting differential-mode signals, thereby improving the insertion loss performance of the circuit.

[0087] Furthermore, this hollowed-out structure alters the distribution of the electromagnetic field within the transmission line's cross-section. More electric field energy is directed towards the low-loss region filled with air, thus reducing concentration in the solid dielectric. This not only helps reduce losses but also improves the power capacity of the circuit structure, as the breakdown field strength of air is typically higher than that of solid dielectric materials.

[0088] For the defective metal ridge structure 03, the surrounding dielectric environment also affects its equivalent capacitance and inductance parameters. The hollowing-out operation adjusts the coupling capacitance between the metal ridge and the upper and lower signal conductors, as well as between the metal ridge and the surrounding ground plane. This provides additional design freedom for tuning the resonant frequency of the defective metal ridge 31, allowing engineers to fine-tune the frequency response of common-mode rejection by controlling the shape and extent of the hollowed-out area without changing the shape and dimensions of the metal ridge itself. This embodiment achieves fine-tuning of the circuit's transmission and resonance characteristics by changing the local filling dielectric without altering the basic circuit topology and external dimensions, simultaneously achieving the dual goals of reducing losses and optimizing performance. This process can be implemented through standard PCB milling or laser ablation post-processing steps.

[0089] In one embodiment, the thickness of dielectric substrate S1, dielectric substrate S2, dielectric substrate S5 and dielectric substrate S6 along the stacking direction is h1, and the thickness of dielectric substrate S3 and dielectric substrate S4 along the stacking direction is h2, wherein h1>h2.

[0090] In this embodiment, the differential coupler's stacked structure has a specific thickness configuration, with the thickness of metal layers G1 to G12 all being t. The thickness of dielectric substrates S1, S2, S5, and S6 along the stacking direction is h1. The thickness of dielectric substrates S3 and S4 along the stacking direction is h2, satisfying the relationship h1>h2. The diameter of the metallized via is d, and the distance between the centers of adjacent vias is p.

[0091] The thickness configuration determines the vertical structure of the signal transmission path. Metal layers G5, G6, G7, and G8 constitute the inner conductor circuit, where G5 and G8 are the signal conduction band layers, and G6 and G7 are the defect metal ridge layers 31. Dielectric plate S3 is located between metal layers G5 and G6, and dielectric plate S4 is located between metal layers G7 and G8. Since h2 is less than h1, the dielectric spacing between the signal conduction band layers (G5, G8) and the adjacent defect metal ridge layers 31 (G6, G7) is thinner. This thinner dielectric spacing h2 enhances the electric field coupling strength between the signal conduction band and the defect metal ridge 31. In common-mode operation, stronger coupling means a larger equivalent coupling capacitance, which helps to lower the resonant frequency of the LC resonant circuit, or allows the use of a smaller physical size defect metal ridge structure 03 at the same resonant frequency.

[0092] Dielectric substrate S2 is located between metal layers G4 and G5, and dielectric substrate S5 is located between metal layers G8 and G9. Since h1 is greater than h2, the dielectric spacing between the signal conduction layers (G5, G8) and the first reference ground planes above and below (G4, G9) is relatively thick. This thicker dielectric spacing h1 weakens the coupling between the signal conduction layers and the external reference ground plane, thereby reducing the dependence of signal transmission on the ground plane. This helps to concentrate electromagnetic field energy more effectively within the inner core region composed of G5, G6, G7, and G8, improving the circuit's enclosure, reducing outward radiation loss, and minimizing interference from the external environment on circuit performance.

[0093] More specifically, for differential-mode signals, the electric field is mainly distributed in the region between G5 and G8. A thicker h1 results in a greater distance between the upper and lower reference ground planes, minimizing its impact on the differential-mode field distribution. This helps achieve higher differential-mode characteristic impedance and reduces conductor loss. For common-mode signals, the suppression performance mainly depends on the resonance of the defective metal ridge 31. A thinner h2 enhances the coupling between G5 and G6, and between G7 and G8, making the resonance effect of the defective metal ridge 31 more significant, thereby improving the depth and bandwidth control capability of common-mode suppression. The metal layer thickness t affects the conductor's conductive cross-sectional area, thus affecting the conductor's ohmic loss. The via diameter d and the via spacing p determine the density and integrity of the sidewall shielding cavity formed by the metallized via array 11; a smaller p / d ratio provides better electromagnetic shielding.

[0094] An asymmetric dielectric thickness configuration, with h1 > h2, is employed to optimize differential-mode transmission and common-mode rejection performance separately. The thicker h1 primarily serves low-loss, high-isolation transmission of differential-mode signals; the thinner h2 primarily serves to enhance common-mode resonant coupling, achieving effective common-mode rejection. This structural design allows the differential coupler to simultaneously meet the two key requirements of high-performance differential-mode transmission and broadband common-mode rejection in a single stack.

[0095] In summary, this embodiment takes a circuit board-level coupler based on dielectric integrated suspended parallel striplines as an example, using Rogers RT / duroid 5880 material with a relative permittivity of 2.2 and a dielectric loss tangent of 0.0009. The specific physical dimensions of the circuit are as follows:

[0096] The length and width of the two sets of branch lines are l r1 = 6.14mm, w r1 = 1.1mm, l r2 = 5.15mm and w r2 =0.66mm, the length and width of the cavity are l cav = 9.46mm and w cav = 9.35mm, the length of the defect ridge is lin = 4.2mm, width is w in = 3mm, the chamfer side length is q = 1.3mm. The distance from the groove of the defect ridge to the edge of the cavity is g = 1mm, the groove width is s = 0.2mm, and the groove lengths of the four defect ridges are l respectively. c1 = 2.8mm, l c2 = 2.56mm, l c3 = 2.11mm and l c4 =1.28mm. The diameter of the metallized via is d = 0.3mm, the distance between adjacent vias is p = 0.5mm, the thickness of the metal layer is t = 0.017mm, the thickness of dielectric substrates S1, S2, S5, and S6 is h1 = 0.508mm, and the thickness of dielectric substrates S3 and S4 is h2 = 0.254mm.

[0097] according to Figure 5 The simulation results of the differential-mode scattering parameters show that the differential coupler exhibits the following characteristics under differential-mode signal excitation: the input return loss (|Sdd11|) is better than 15dB within 19.6% of the relative bandwidth, and the port isolation is also better than 15dB. This indicates that the structure achieves good impedance matching and port isolation within the target frequency band. Figure 6 The simulation results of the phase characteristics shown indicate that, under differential mode operation, the phase difference between the through port and the coupled port remains stable at around 90 degrees within the operating frequency band, meeting the basic functional requirements of a branch-line coupler. According to... Figure 7 The simulation results of the common-mode scattering parameters show that when a common-mode signal is input from port A (i.e., the differential port formed by port 1 and port 1'), the amplitudes of its transmission parameters Scc21, Scc31, and Scc41 are all below -20dB in the frequency range of 9.2GHz to 11.2GHz. This indicates that the structure effectively suppresses common-mode signals in this frequency band, with a suppression depth exceeding 20dB. According to... Figure 8 The simulation results of cross-mode suppression shown indicate that the cross-mode suppression of this differential coupler is better than 25dB within the operating frequency band, demonstrating that the conversion between differential and common-mode signals is effectively controlled.

[0098] Based on the simulation results above, the differential coupler designed in this embodiment achieves both good differential-mode operating characteristics and effective common-mode signal suppression in the frequency range of 9.2 GHz to 11.2 GHz (relative bandwidth of 19.6%). The differential-mode operating characteristics include low return loss, high isolation, and a stable 90-degree phase difference; the common-mode suppression characteristics exhibit a suppression depth exceeding 20 dB. This design verifies the feasibility of achieving a high-performance, self-encapsulated differential coupler based on the dielectric integrated suspension line platform 01 and the integrated defective metal ridge structure 03.

[0099] Furthermore, to achieve the above objectives, this application also proposes a communication device including a coupler based on a dielectric-integrated suspended parallel stripline as described in any of the foregoing embodiments. This coupler serves as a component of the communication device's radio frequency front-end or microwave / millimeter-wave circuit module. Its specific functions include, but are not limited to: achieving directional coupling of signals, power distribution and combining, and constituting a key component in a balanced mixer, phase shifter, or beamforming network.

[0100] Because the coupler employs a dielectric-integrated suspension line platform 01 and an integrated defective metal ridge structure 03, it features self-encapsulation, low loss, high common-mode rejection, and ease of planar integration. Applying these couplers to communication equipment yields the following direct benefits: reducing the need for external shielding cavities or independently packaged components, thereby reducing the overall size and weight of the equipment. Its low-loss characteristics help reduce the cascaded noise figure of the system or improve transmission efficiency. Its high common-mode rejection capability effectively suppresses common-mode noise and electromagnetic interference in the circuit, improving the signal integrity and anti-interference capability of the communication link. Its planar structure facilitates integration with other active and passive circuit modules using standard printed circuit board processes, which is beneficial for miniaturizing and high-density RF front-ends of communication equipment.

[0101] The communication equipment may be, but is not limited to, base station equipment, satellite communication terminals, microwave relay equipment, radar systems, test and measurement instruments, or any electronic device containing a radio frequency front-end. In this equipment, the coupler is electrically connected to other circuits in the system, such as amplifiers, filters, antennas, or digital processing units, through its input / output ports to jointly achieve specific communication or signal processing functions.

[0102] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A coupler based on a dielectric integrated suspended parallel stripline, characterized in that, include: The dielectric integrated suspension line platform has an electromagnetic shielding cavity and an air cavity located within the electromagnetic shielding cavity; A differential coupler circuit, suspended within the air cavity, includes a first signal guide band and a second signal guide band arranged vertically opposite to each other, the first signal guide band and the second signal guide band forming a balanced transmission line structure; A defective metal ridge structure is disposed between the first signal conductor and the second signal conductor; The defective metal ridge structure is used to couple with the first signal conduction band and the second signal conduction band to generate resonance under common-mode signal excitation, so as to suppress the common-mode signal.

2. The coupler based on dielectric integrated suspended parallel stripline according to claim 1, characterized in that, The dielectric integrated suspension line platform includes six dielectric boards S1~S6 stacked from top to bottom and an array of metallized through holes penetrating each dielectric board. The upper and lower surfaces of each dielectric board are coated with copper to form a metal layer. The metal layer on the upper surface of the dielectric substrate S1, the metal layer on the lower surface of the dielectric substrate S6, and the metallized through-hole array form an electromagnetic shielding cavity. A first air cavity is formed by hollowing out the middle of the dielectric plate S2 and its upper and lower metal layers, and a second air cavity is formed by hollowing out the middle of the dielectric plate S5 and its upper and lower metal layers. The first signal conduction band and the second signal conduction band are respectively etched on the metal layer on the upper surface of the dielectric substrate S3 and the metal layer on the lower surface of the dielectric substrate S4; The defective metal ridge structure is etched on the metal layer on the lower surface of the dielectric substrate S3 and the metal layer on the upper surface of the dielectric substrate S4.

3. The coupler based on dielectric integrated suspended parallel strip line according to claim 2, characterized in that, The defective metal ridge structure includes: Multiple defective metal ridges are arranged parallel to and opposite to the first signal conduction band and the second signal conduction band, and are used to couple with the first signal conduction band and the second signal conduction band to form an LC resonant circuit under common-mode signal excitation, so as to generate resonance at the target resonant frequency. The length of the defective metal ridge is set to match the target resonant frequency.

4. The coupler based on dielectric integrated suspended parallel strip line according to claim 2, characterized in that, The defective metal ridge structure is structurally symmetrical with respect to the first signal conduction band and the second signal conduction band, such that the potential of the defective metal ridge is 0V under differential mode signal excitation.

5. The coupler based on dielectric integrated suspended parallel strip line according to claim 3, characterized in that, The input / output ports of the first signal conductor are led out along a first direction, and the input / output ports of the second signal conductor are led out along a second direction perpendicular to the first direction.

6. The coupler based on dielectric integrated suspended parallel stripline according to claim 5, characterized in that, The metallized via array includes multiple rows of vias arranged along the first direction and the second direction; Specifically, in the region corresponding to the first signal conductor input / output port, the via has a first lead-out notch at the dielectric substrate S3 and its upper and lower metal layers; in the region corresponding to the second signal conductor input / output port, the via has a second lead-out notch at the dielectric substrate S4 and its upper and lower metal layers.

7. The coupler based on dielectric integrated suspended parallel stripline according to claim 5, characterized in that, The differential coupler circuit is a branch-line coupler with four transmission branches, and each defective metal ridge is configured to correspond to one transmission branch of the differential coupler circuit.

8. The coupler based on dielectric integrated suspended parallel stripline according to claim 3, characterized in that, The dielectric plates S3 and S4 are hollowed out in the areas not covered by the first signal guide, the second signal guide, and the defective metal ridge.

9. The coupler based on dielectric integrated suspended parallel strip line according to claim 2, characterized in that, The thickness of dielectric substrate S1, dielectric substrate S2, dielectric substrate S5 and dielectric substrate S6 along the stacking direction is h1, and the thickness of dielectric substrate S3 and dielectric substrate S4 along the stacking direction is h2, wherein h1>h2.

10. A communication device, characterized in that, Including the coupler based on dielectric integrated suspended parallel strip as described in any one of claims 1-9.

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