CN106099379A - The integrated non-radiative Medium Wave Guide leaky-wave antenna of substrate - Google Patents

Abstract

The invention discloses a substrate-integrated non-radiative dielectric waveguide leaky wave antenna, which is a three-layer circuit structure composed of a coplanar waveguide and a three-layer substrate-integrated non-radiative dielectric waveguide, wherein the substrate-integrated non-radiative dielectric waveguide is It is realized by designing a series of air holes on the printed circuit board. The coplanar waveguide is integrated in the middle layer of the circuit. The coplanar waveguide is connected to the substrate through the triangular gradient structure to integrate the non-radiative dielectric waveguide, and the triangular gradient structure is adjusted at the same time. Impedance matching; a rectangular slot is opened on the bottom dielectric plate at the same end as the coplanar waveguide, which avoids interference to the performance of the coplanar waveguide while stabilizing the circuit. The invention can successfully realize the integration of non-radiative dielectric waveguide by connecting the coplanar waveguide to the substrate, and excite the high-order mode with better radiation performance, thereby forming a periodic leaky wave antenna and realizing the integration of microwave and millimeter wave hybrid multilayer circuits at the same time, It is beneficial to the design of the millimeter wave frequency band circuit, the manufacturing process is simple, and the cost is low.

Description

Substrate Integrated Nonradiative Dielectric Waveguide Leaky Wave Antenna

technical field

The invention relates to a substrate-integrated non-radiative dielectric waveguide leaky-wave antenna, in particular to a substrate-integrated non-radiative dielectric waveguide periodic leaky-wave antenna excited by a coplanar waveguide, which belongs to the field of microwave technology.

Background technique

With the research and development of millimeter-wave frequency band circuits, waveguide structures with low transmission loss and easy integration with planar circuit structures are favored. The radiation-free nature of the discontinuity makes it a promising millimeter-wave component.

There are precision and structural stability problems when non-radiative dielectric waveguides are applied to millimeter-wave circuit design. At the same time, as the frequency increases, the size of non-radiative dielectric waveguides will decrease, which affects the non-radiative dielectric waveguides and traditional planar circuits. Hybrid integration, substrate-integrated non-radiative dielectric waveguide is a planar non-radiative dielectric waveguide structure realized by applying substrate integration technology to traditional non-radiative dielectric waveguide. It overcomes the structural defects of non-radiative dielectric waveguide and realizes traditional non-radiative The planarization of the radiative dielectric waveguide, and the direct realization of the non-radiative dielectric waveguide structure on the printed circuit board or the metal-coated dielectric board are proposed, and the selection of the appropriate hole position and size can reduce the cut-off surface current as much as possible to reduce the radiation loss. , on the basis of this structure, a transition circuit is designed to realize a microwave and millimeter wave hybrid multilayer circuit, and a loose array of air holes is designed to realize a periodic leaky wave antenna.

Contents of the invention

The technical problem to be solved by the present invention is to provide a substrate-integrated non-radiative dielectric waveguide leaky-wave antenna, which is a substrate-integrated non-radiative dielectric waveguide periodic leaky-wave antenna excited by a coplanar waveguide. The substrate integrates the non-radiative dielectric waveguide to form a three-layer microwave and millimeter wave circuit structure, and the leaky wave antenna is realized through the design of the non-radiative dielectric waveguide through-hole.

The present invention adopts the following technical solutions for solving the problems of the technologies described above:

The invention provides a substrate-integrated non-radiative dielectric waveguide leaky-wave antenna, comprising a top dielectric board, a middle dielectric board, a bottom dielectric board, a top metal layer, a bottom metal layer, a top dielectric board, a middle dielectric board and a bottom dielectric board Coaxially stacked; the length of the top dielectric board is smaller than that of the middle dielectric board and the bottom dielectric board, and the width is equal to that of the middle layer dielectric board and the bottom dielectric board.

The top metal layer is arranged on the upper surface of the top dielectric board, the bottom metal layer is arranged on the lower surface of the bottom dielectric board, and the bottom metal layer coincides with the projection of the top metal layer on the lower surface of the bottom dielectric board.

In the non-overlapping area between the middle layer dielectric board and the top layer dielectric board, on the upper surface of the middle layer dielectric board, a coplanar waveguide is set inward from a short side of the middle layer dielectric board, wherein the central conduction band of the coplanar waveguide is along the middle medium The long side direction of the plate extends to the folding line, and the edges of the metal grounding plates on both sides of the coplanar waveguide close to the short side of the middle dielectric board coincide with the edge of the projection of the top metal layer on the middle dielectric board.

In the overlapping area of the top dielectric board, the middle dielectric board, and the bottom dielectric board, a dielectric strip is reserved along the fold line along the long side, and arrayed air holes are arranged symmetrically on both sides of the dielectric strip to form a substrate integration A non-radiative dielectric waveguide; wherein the spacing between the air vias close to the coplanar waveguide is smaller than the spacing between the air vias farther from the coplanar waveguide.

On the upper surface of the intermediate layer dielectric plate, at the end of the coplanar waveguide close to the substrate-integrated non-radiative dielectric waveguide, a first triangular tapered structure is set inwardly along the dielectric strip from one end of the central guide band of the coplanar waveguide, and from the coplanar waveguide The metal grounding plates on both sides are provided with second and third triangular gradient structures inwardly along the dielectric strip on the side close to the central conduction band, so as to connect the coplanar waveguide to the substrate integrated non-radiative dielectric waveguide; wherein, the first triangular The gradient structure is symmetrical to the fold line with respect to the long side direction, and the second and third triangular gradient structures are symmetrical to the fold line with respect to the long side direction.

On the lower surface of the bottom dielectric plate, from the short side of the bottom metal layer close to the coplanar waveguide, two trapezoidal grooves are made inward along the dielectric strip to match the first to third triangular gradient structures on the middle layer dielectric plate ; Among them, the two trapezoidal grooves are symmetrical to the broken line with respect to the long side direction.

As a further optimization solution of the present invention, the size of the arrayed air through holes and the spacing between the air through holes are determined according to the operating frequency of the circuit.

As a further optimization solution of the present invention, the size of the arrayed air through holes and the spacing between the air through holes are determined according to the operating frequency of the circuit.

As a further optimization solution of the present invention, the first to third triangular tapered structures are located in the dielectric strip area reserved for the substrate-integrated non-radiative dielectric waveguide.

As a further optimization solution of the present invention, a rectangular groove is opened inward from the short side of the bottom dielectric plate close to the coplanar waveguide to stabilize the circuit; wherein, the rectangular groove is symmetrical to the fold line with respect to the long side direction.

As a further optimization solution of the present invention, the length of the above-mentioned rectangular slot is equal to the length of the coplanar waveguide by bisecting the line along the long side direction.

Compared with the prior art, the present invention adopts the above technical scheme and has the following technical effects: the present invention simplifies the manufacturing process of the non-radiative dielectric waveguide, and effectively suppresses the leakage of the substrate-integrated non-radiative dielectric waveguide at the dense array air through holes The loss increases the leakage loss of the substrate-integrated non-radiative waveguide at the loose array air hole; the integration of multi-layer circuits realizes the planarization of the circuit, simplifies the manufacturing process and reduces the corresponding processing cost; At the same time, the present invention adopts a three-layer circuit structure, fully utilizes the space, and connects the coplanar waveguide from the middle of the substrate-integrated non-radiative dielectric waveguide, and the triangular gradient structure can realize better transition performance. At the same time, the manufacturing process is flexible and simple, which can realize the connection of the coplanar waveguide to the substrate integrated non-radiative dielectric waveguide three-layer circuit to form a periodic leaky wave antenna, which provides a basis for the design of other types of antennas in the microwave and millimeter wave band hybrid integrated multilayer circuits.

Description of drawings

Fig. 1 is a three-dimensional structure diagram of the present invention.

Fig. 2 is a top view and a side view of the present invention, wherein (a) is a top view, and (b) is a side view.

Among them, 1-metal grounding plate; 2-center conduction band; 3-gap between the center conduction band and metal grounding plate; 4-triangular gradient structure; 5-trapezoidal groove; 6-periodic spacing D1; 7-periodic Spacing D2; 8-rectangular slot; 9-top dielectric board; 10-intermediate dielectric board; 11-bottom dielectric board.

Figure 3 is a top view of the top dielectric board.

Fig. 4 is a top view of the middle layer dielectric plate.

Fig. 5 is a bottom view of the middle layer dielectric plate.

Figure 6 is a bottom view of the bottom dielectric board.

Fig. 7 is a simulation S-parameter diagram of the embodiment of the present invention.

Fig. 8 is a simulation direction diagram of the embodiment of the present invention.

detailed description

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:

The present invention provides a substrate-integrated non-radiative dielectric waveguide leaky-wave antenna, which is a periodic leaky-wave antenna realized by a three-layer circuit structure composed of a coplanar waveguide connected to a three-layer substrate integrated non-radiative dielectric waveguide, as shown in the figure 1 to 6, where the coplanar waveguide and the substrate-integrated non-radiative dielectric waveguide are integrated on the same dielectric board; On-chip integrated non-radiative dielectric waveguide to achieve impedance matching; a rectangular slot is opened on the bottom dielectric plate, which can stabilize the circuit while avoiding the impact on the performance of the coplanar waveguide; two openings are made from the bottom metal layer close to the short side of the coplanar waveguide. The first trapezoidal groove matches the three triangular gradient structures at the intermediate dielectric substrate to better achieve impedance matching at the transition, and the two trapezoidal grooves are symmetrical about the fold line in the direction of the long side.

The substrate-integrated non-radiative dielectric waveguide is realized on a three-layer dielectric board. The manufacturing method is as follows: the three-layer dielectric board and the metal layers on the upper and lower surfaces are used as the metal plate of the traditional non-radiative dielectric waveguide, and the middle area of the dielectric board is A dielectric strip is reserved, and a series of arrayed air holes are designed on both sides of the dielectric strip to form a substrate-integrated non-radiative dielectric waveguide. Among them, the number of air through holes is determined by the size of the printed circuit board; the diameter and spacing of the air through holes are related to the operating frequency of the circuit, which affects the design of the periodic leaky wave antenna.

In the embodiment of the present invention, the thickness of the intermediate layer dielectric substrate where the coplanar waveguide is located is 0.635 mm , and the relative permittivity is 6.15 ; the total thickness of the three-layer dielectric substrate is 5.715 mm (the thickness of the bottom dielectric plate is 2.54 mm , plate is 0.635 mm , the top dielectric plate is 2.54 mm ), the relative permittivity is 6.15 ; the length of the triangular gradient structure is 4.8 mm , and the outward width is 3.05 mm . The substrate integrated non-radiative medium simulated by 3D electromagnetic simulation software The magnetic field distribution in the waveguide (operating frequency 21GHz), as shown in Figure 8. Figure 8 shows that the substrate-integrated non-radiative dielectric waveguide based on the printed circuit board can be applied to millimeter-wave band circuit design, and can be mixed and integrated into a multilayer circuit; further, the present invention proposes a transition circuit from a coplanar waveguide to a substrate-integrated waveguide, It can effectively realize the planarization of the circuit and the hybrid integration of microwave and millimeter wave multilayer circuits. The corresponding simulation results are shown in Figure 7. The frequency bandwidth at which the return loss drops below -20dB is 4GHz, which shows that the transition circuit has a good performance. transmission.

The transition circuit from the coplanar waveguide to the substrate-integrated non-radiative dielectric waveguide makes full use of space, reduces electromagnetic interference, and uses a triangular gradient structure with better performance to realize access from the middle to the substrate-integrated non-radiative dielectric waveguide. The arrayed air via holes in the substrate-integrated non-radiative dielectric waveguide, the spacing of the via holes near the coplanar waveguide is smaller than the part far away from the coplanar waveguide, and the arrayed air via holes with small spacing can effectively suppress electromagnetic waves in the substrate integrated non-radiative waveguide. The leakage loss propagating in the radiative dielectric waveguide, and the design of the arrayed air holes with large spacing make the electromagnetic wave radiate periodically. Therefore, the present invention provides a basis for designing other types of antennas of hybrid integrated multilayer circuits in the microwave and millimeter wave bands.

The above is only a specific implementation mode in the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technology can understand the conceivable transformation or replacement within the technical scope disclosed in the present invention. All should be covered within the scope of the present invention, therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (5)

1. The substrate integrated non-radiative dielectric waveguide leaky wave antenna is characterized in that it comprises a top dielectric board, an intermediate dielectric board, a bottom dielectric board, a top metal layer, a bottom metal layer, a top dielectric board, an intermediate dielectric board and a bottom dielectric The boards are stacked coaxially; the length of the top dielectric board is smaller than that of the middle dielectric board and the bottom dielectric board, and the width is equal to that of the middle dielectric board and the bottom dielectric board; The top metal layer is arranged on the upper surface of the top dielectric board, the bottom metal layer is arranged on the lower surface of the bottom dielectric board, and the projection of the bottom metal layer and the top metal layer on the lower surface of the bottom dielectric board coincides; In the non-overlapping area between the middle layer dielectric board and the top layer dielectric board, on the upper surface of the middle layer dielectric board, a coplanar waveguide is set inward from a short side of the middle layer dielectric board, wherein the central conduction band of the coplanar waveguide is along the middle medium The long side direction of the plate is extended to the folding line, and the edge of the metal ground plate on both sides of the coplanar waveguide close to the short side direction of the middle layer dielectric board is coincident with the edge of the projection of the top metal layer on the middle layer dielectric board; In the overlapping area of the top dielectric board, the middle dielectric board, and the bottom dielectric board, a dielectric strip is reserved along the fold line along the long side, and arrayed air holes are arranged symmetrically on both sides of the dielectric strip to form a substrate integration A non-radiative dielectric waveguide; wherein the spacing between the air vias near the coplanar waveguide is smaller than the spacing between the air vias away from the coplanar waveguide; On the upper surface of the intermediate layer dielectric plate, at the end of the coplanar waveguide close to the substrate-integrated non-radiative dielectric waveguide, a first triangular tapered structure is set inwardly along the dielectric strip from one end of the central guide band of the coplanar waveguide, and from the coplanar waveguide The metal grounding plates on both sides are provided with second and third triangular gradient structures inwardly along the dielectric strip on the side close to the central conduction band, so as to connect the coplanar waveguide to the substrate integrated non-radiative dielectric waveguide; wherein, the first triangular The gradient structure is symmetrical to the fold line in the direction of the long side, and the second and third triangular gradient structures are symmetrical to the fold line in the direction of the long side; On the lower surface of the bottom dielectric plate, from the short side of the bottom metal layer close to the coplanar waveguide, two trapezoidal grooves are made inward along the dielectric strip to match the first to third triangular gradient structures on the middle layer dielectric plate ; Among them, the two trapezoidal grooves are symmetrical to the broken line with respect to the long side direction. 2. The substrate-integrated non-radiative dielectric waveguide leaky wave antenna according to claim 1, characterized in that the size of the arrayed air through holes and the spacing between the air through holes are determined according to the operating frequency of the circuit. 3. The substrate-integrated non-radiative dielectric waveguide leaky-wave antenna according to claim 1, wherein the first to third triangular tapered structures are located in the reserved dielectric strip area of the substrate-integrated non-radiative dielectric waveguide. 4. The substrate-integrated non-radiative dielectric waveguide leaky-wave antenna according to claim 1, wherein a rectangular slot is opened inwardly from the bottom dielectric plate near the short side of the coplanar waveguide to stabilize the circuit; wherein the rectangular slot Symmetrical to the polyline about the long side direction. 5. The substrate-integrated non-radiative dielectric waveguide leaky-wave antenna according to claim 4, characterized in that, along the long-side direction of the zigzag line, the length of the rectangular slot is equal to the length of the coplanar waveguide.