阅读说明：本技术 一种用于改善微波无源器件性能的基片集成慢波空波导 (Substrate integrated slow wave air waveguide for improving performance of microwave passive device ) 是由 羌静霞 许锋 于 2019-10-28 设计创作，主要内容包括：本发明揭示了一种用于改善微波无源器件性能的基片集成慢波空波导,该基片集成慢波空波导包括上层介质板、中层介质板和下层介质板,上层介质板、中层介质板和下层介质板固定连接,上层介质板、中层介质板和下层介质板由上至下按序组成三层波导结构,上层介质板的下表面覆盖有第一底层金属层,中层介质板的上表面覆盖有第一顶层金属层,下层介质板的上表面覆盖有第二顶层金属层,下表面覆盖有第二底层金属层。本技术方案在保持基片集成空波导优点的同时,结合慢波效应,克服了高Q值与小型化难以结合的问题,在低损耗微波集成化电路中具有重要的应用价值,更适合应用于小型化、高Q值、低损耗等多方面要求严格的微波电路系统中。(The invention discloses a substrate integrated slow wave air waveguide for improving the performance of a microwave passive device, which comprises an upper dielectric plate, a middle dielectric plate and a lower dielectric plate, wherein the upper dielectric plate, the middle dielectric plate and the lower dielectric plate are fixedly connected, the upper dielectric plate, the middle dielectric plate and the lower dielectric plate form a three-layer waveguide structure from top to bottom in sequence, the lower surface of the upper dielectric plate is covered with a first bottom metal layer, the upper surface of the middle dielectric plate is covered with a first top metal layer, the upper surface of the lower dielectric plate is covered with a second top metal layer, and the lower surface is covered with a second bottom metal layer. The technical scheme combines the slow wave effect while keeping the advantages of the substrate integrated air waveguide, overcomes the problem that high Q value and miniaturization are difficult to combine, has important application value in a low-loss microwave integrated circuit, and is more suitable for being applied to microwave circuit systems with strict requirements in various aspects such as miniaturization, high Q value, low loss and the like.)

1. A substrate integrated slow wave air waveguide for improving the performance of a microwave passive device is characterized in that: comprises an upper dielectric slab (1), a middle dielectric slab (2) and a lower dielectric slab (3), wherein the upper dielectric slab (1), the middle dielectric slab (2) and the lower dielectric slab (3) are fixedly connected, the upper dielectric slab (1), the middle dielectric slab (2) and the lower dielectric slab (3) form a three-layer waveguide structure in sequence from top to bottom,

the lower surface of the upper dielectric slab is covered with a first bottom metal layer (4), the upper surface of the middle dielectric slab is covered with a first top metal layer (5), the upper surface of the lower dielectric slab is covered with a second top metal layer (6), and the lower surface is covered with a second bottom metal layer (7).

2. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 1, wherein: the periphery of the upper-layer dielectric plate (1), the middle-layer dielectric plate (2) and the lower-layer dielectric plate (3) is respectively and uniformly distributed with at least eight through holes (8) matched with the connecting pieces, the size of each through hole is consistent, and the connecting pieces are screws.

3. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 1, wherein: the upper dielectric plate (1), the middle dielectric plate (2) and the lower dielectric plate (3) are all Rogers 4003C dielectric plates, the dielectric constant is 3.55, the loss tangent is 0.027, and the thickness is 0.813 mm.

4. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 1, wherein: the transmission part of the middle-layer dielectric plate (2) is integrally hollowed to form a rectangular air waveguide, a feed port (9) is arranged on the first top-layer metal layer (5), a conical transition structure (10) is arranged on the rectangular air waveguide, the feed port (9) performs impedance matching on a conical asymptote of transition from the middle-layer dielectric plate to the air waveguide, and the side wall of the rectangular air waveguide except for the asymptote of feed is an electric wall (13), namely all metal.

5. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 4, wherein: the transition structure of the feed port of the middle dielectric layer is exponentially decreased gradually, and the tail end of the transition structure is in an arc shape.

6. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 4, wherein: the width of the feed port (9) is equal to the width of the substrate integrated slow wave air waveguide impedance matching.

7. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 1, wherein: and a feed port (9) is arranged on the left side of the first top metal layer (5) of the middle-layer dielectric plate, and the feed port (9) is connected with the conical asymptote.

8. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 1, wherein: the lower dielectric plate is provided with two rows of first metalized through holes (11) with uniform intervals along a metal wall (13) of the air waveguide of the middle dielectric layer, the intervals between the through holes are equal, the middle part of the lower dielectric plate is provided with uniform and dense second metalized through holes (12), and the second metalized through holes are uniformly distributed below the air waveguide of the middle dielectric layer, namely the inner sides of the two rows of first metalized through holes (11).

9. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 8, wherein: the top layer of the lower dielectric plate is arranged outside the two rows of first metalized through holes, namely outside the air waveguide of the middle dielectric layer and is made of metal; the bottom layer of the lower dielectric plate is ground, namely metal.

10. The substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to claim 1, wherein: the length of the upper dielectric plate (1) is smaller than that of the middle dielectric plate (2) and that of the lower dielectric plate (3), the length of the middle dielectric plate (2) is consistent with that of the lower dielectric plate (3), and the height and width of the upper dielectric plate (1), the middle dielectric plate (2) and that of the lower dielectric plate (3) are consistent.

Technical Field

The invention relates to a substrate integrated slow wave air waveguide for improving the performance of a microwave passive device, which can be used in the technical field of microwaves.

Background

With the rapid development of modern technologies, wireless communication technologies are being developed in the directions of miniaturization, high performance, and high integration. The substrate integrated waveguide is widely applied to microwave circuits due to the characteristics of high Q value, low loss, easy integration and the like. As circuits evolve, particularly at high frequencies, the presence of dielectrics limits the performance of the devices, and substrate losses increase insertion loss and reduce the quality factor. In order to solve the problem, the medium is removed from the substrate integrated waveguide to form the air waveguide, and the advantages of low cost and low profile are maintained. Thus. The application research of the substrate integrated circuit with high Q value has important theoretical value and engineering practical significance for realizing high-performance modern microwave millimeter wave passive devices and active circuits.

Due to the characteristic that the substrate integrated hollow waveguide removes media, the size of the substrate integrated hollow waveguide is relatively large, the profile is greatly increased due to the substrate integrated folded hollow waveguide, and the Q value is greatly reduced due to the substrate integrated half hollow waveguide, so that the problem of how to reduce the size of the substrate integrated hollow waveguide on the basis of keeping the high Q value is also solved.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a substrate integrated slow wave air waveguide for improving the performance of a microwave passive device.

The purpose of the invention is realized by the following technical scheme: the utility model provides an integrated slow wave air waveguide of substrate for improving microwave passive device performance, includes upper dielectric plate, middle level dielectric plate and lower floor dielectric plate, upper dielectric plate, middle level dielectric plate and lower floor dielectric plate fixed connection, upper dielectric plate, middle level dielectric plate and lower floor dielectric plate constitute three-layer waveguide structure in proper order from top to bottom, and the lower surface of upper dielectric plate covers has first bottom metal level, and the upper surface of middle level dielectric plate covers has first top metal level, and the upper surface of lower floor dielectric plate covers has second top metal level, and the lower surface covers has second bottom metal level.

Preferably, the periphery of the upper dielectric plate, the middle dielectric plate and the lower dielectric plate is respectively and equally distributed with at least eight through holes matched with the connecting pieces, the size of each through hole is consistent, and the connecting pieces are screws.

Preferably, the upper dielectric plate, the middle dielectric plate and the lower dielectric plate are both Rogers 4003C dielectric plates, the dielectric constant is 3.55, the loss tangent is 0.027, and the thickness is 0.813 mm.

Preferably, the transmission part of the middle dielectric plate is integrally hollowed to form a rectangular air waveguide, the feed port is arranged on the first top metal layer, a tapered transition structure is arranged on the rectangular air waveguide, the feed port performs impedance matching from a tapered asymptote of the transition from the middle dielectric plate to the air waveguide, and the side wall of the rectangular air waveguide except for the asymptote of the feed is an electric wall, that is, all the side wall is metal.

Preferably, the transition structure of the feed port of the middle dielectric layer is exponentially decreased, and the tail end of the transition structure is in an arc shape.

Preferably, the width of the feed port is equal to the width of the substrate integrated slow wave air waveguide impedance matching.

Preferably, a feed port is arranged on the left side of the first top metal layer of the middle-layer dielectric plate, and the feed port is connected with the tapered asymptote.

Preferably, the lower dielectric plate is provided with two rows of first metalized through holes with uniform intervals along the metal wall of the air waveguide of the middle dielectric layer, the intervals between the through holes are equal, the middle part of the lower dielectric plate is provided with uniform and dense second metalized through holes, and the second metalized through holes are uniformly distributed below the air waveguide of the middle dielectric layer, namely the inner sides of the two rows of first metalized through holes.

Preferably, the top layer of the lower dielectric plate is arranged outside the two rows of first metalized through holes, namely outside the air waveguide of the middle dielectric layer, and is made of metal; the bottom layer of the lower dielectric plate is ground, namely metal.

Preferably, the length of the upper dielectric plate is smaller than the lengths of the middle dielectric plate and the lower dielectric plate, the lengths of the middle dielectric plate and the lower dielectric plate are consistent, and the heights and the widths of the upper dielectric plate, the middle dielectric plate and the lower dielectric plate are consistent.

Compared with the prior art, the invention adopting the technical scheme has the following technical effects: the technical scheme combines the slow wave effect while keeping the advantages of the substrate integrated air waveguide, overcomes the problem that high Q value and miniaturization are difficult to combine, and has important application value in a low-loss microwave integrated circuit. The technical scheme is that on the basis of substrate integrated air waveguide, metal through holes are uniformly arranged in a lower-layer dielectric slab, so that an electric field is concentrated in the air waveguide, and a magnetic field is still distributed in the whole structure, so that the longitudinal and transverse dimensions are reduced simultaneously.

Compared with the traditional substrate integrated slow wave structure, the waveguide improves the Q value by nearly 8 times, and greatly reduces the insertion loss; compared with the traditional substrate integrated hollow waveguide structure, the waveguide structure is more compact. On the basis of keeping the three-layer structure of the air waveguide, the invention does not increase the processing difficulty and cost, realizes the combination of high Q value and miniaturization, and is more suitable for being applied to microwave circuit systems with strict requirements in various aspects such as miniaturization, high Q value, low loss and the like.

Drawings

Fig. 1 is a top view of a substrate integrated slow wave air waveguide for improving the performance of a microwave passive device according to the present invention.

Fig. 2 is a top view of a fourth order filter of the present invention for substrate integrated slow wave air waveguides for improved microwave passive device performance.

Fig. 3 is a schematic diagram of an intermediate layer air waveguide of the substrate integrated slow wave air waveguide of the present invention for improving the performance of microwave passive devices.

Fig. 4 is a three-dimensional split view of a substrate-integrated slow wave air waveguide for improving microwave passive device performance in accordance with the present invention.

Fig. 5 is a three-dimensional split view of a substrate integrated slow wave air waveguide fourth order filter for improving microwave passive device performance in accordance with the present invention.

FIG. 6 is a cross-sectional view of the internal electric field of the substrate integrated slow wave air waveguide for improving the performance of the microwave passive device.

FIG. 7 is a cross-sectional view of the internal magnetic field of the substrate integrated slow wave air waveguide for improving the performance of the microwave passive device according to the present invention.

FIG. 8 is a simulation diagram of S-parameters of a substrate integrated slow-wave air waveguide for improving the performance of a microwave passive device according to the present invention.

Fig. 9 is a comparison of the simulation and actual measurement results of the S parameter of the fourth-order filter of the substrate integrated slow wave air waveguide for improving the performance of the microwave passive device.

Detailed Description

Objects, advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments. The embodiments are merely exemplary for applying the technical solutions of the present invention, and any technical solution formed by replacing or converting the equivalent thereof falls within the scope of the present invention claimed.

The invention discloses a substrate integrated slow wave air waveguide for improving the performance of a microwave passive device, which comprises an upper dielectric plate 1, a middle dielectric plate 2 and a lower dielectric plate 3, wherein the upper dielectric plate 1, the middle dielectric plate 2 and the lower dielectric plate 3 are fixedly connected, and the upper dielectric plate 1, the middle dielectric plate 2 and the lower dielectric plate 3 form a three-layer waveguide structure in sequence from top to bottom, as shown in figures 1, 2, 3 and 4.

The length of the upper dielectric plate 1 is smaller than that of the middle dielectric plate 2 and that of the lower dielectric plate 3, the length of the middle dielectric plate 2 is consistent with that of the lower dielectric plate 3, and the height and width of the upper dielectric plate 1, the middle dielectric plate 2 and that of the lower dielectric plate 3 are consistent.

The lower surface of the upper dielectric slab is covered with a first bottom metal layer 4, the upper surface of the middle dielectric slab is covered with a first top metal layer 5, the upper surface of the lower dielectric slab is covered with a second top metal layer 6, and the lower surface is covered with a second bottom metal layer 7.

The periphery of the upper dielectric plate 1, the middle dielectric plate 2 and the lower dielectric plate 3 is respectively and equally distributed with at least eight through holes 8 matched with the connecting pieces, the size of each through hole is consistent, and the connecting pieces are screws. The upper dielectric plate 1, the middle dielectric plate 2 and the lower dielectric plate 3 are both Rogers 4003C dielectric plates, the dielectric constant is 3.55, the loss tangent is 0.027, and the thickness is 0.813 mm.

The transmission part of the middle-layer dielectric plate 2 is integrally hollowed to form a rectangular air waveguide, a feed port 9 is arranged on the first top-layer metal layer 5, a tapered transition structure 10 is arranged on the rectangular air waveguide, the feed port 9 performs impedance matching from a tapered asymptote of transition from the middle-layer dielectric plate to the air waveguide, and the side wall of the rectangular air waveguide except for the asymptote of feed is provided with an electric wall 13, namely all the electric wall is metal. The transition structure of the feed port of the middle dielectric layer is exponentially decreased gradually, and the tail end of the transition structure is in an arc shape. The width of the feed port 9 is equal to the width of the substrate integrated slow wave air waveguide impedance matching. And a feed port 9 is arranged on the left side of the first top metal layer 5 of the middle-layer dielectric plate, and the feed port 9 is connected with the conical asymptote.

The lower dielectric plate is provided with two rows of first metalized through holes 11 with uniform intervals along a metal wall 13 of the air waveguide of the middle dielectric layer, the intervals between the through holes are equal, the middle part of the lower dielectric plate is provided with uniform and dense second metalized through holes 12, and the second metalized through holes are uniformly distributed below the air waveguide of the middle dielectric layer, namely the inner sides of the two rows of first metalized through holes 11. The top layer of the lower dielectric plate is arranged outside the two rows of first metalized through holes, namely outside the air waveguide of the middle dielectric layer and is made of metal; the bottom layer of the lower dielectric plate is ground, namely metal.

As shown in fig. 5, the substrate-integrated slow wave air waveguide sequentially includes, from top to bottom, an upper dielectric substrate, an upper bottom metal layer, a middle top metal layer, a middle dielectric substrate, a lower top metal layer, a lower dielectric substrate, and a lower bottom metal layer.

The upper dielectric plate 1, the middle dielectric plate 2 and the lower dielectric plate 3 are both Rogers 4003C dielectric plates, the dielectric constant is 3.55, the loss tangent is 0.027, the thickness is 0.813mm, and metalized through holes are uniformly distributed on the lower dielectric substrate. The width of the substrate integrated slow wave air waveguide is 14.45mm, and the width of the substrate integrated slow wave air waveguide under the same working frequency band is 19.05mm, so that the size of the substrate integrated slow wave air waveguide is reduced by 24%. The unloaded Q value of the substrate integrated slow wave air waveguide is up to 1680, which is 5.35 times of the Q value of the substrate integrated slow wave waveguide and 6.04 times of the Q value of the substrate integrated slow wave waveguide.

As shown in fig. 3, the microstrip line is connected to the substrate integrated slow wave air waveguide through a tapered transition structure, and serves as an input port of the waveguide. For better impedance matching, the conical transition structure is in exponential distribution and gradually changes, and the tail end is in a circular arc shape.

Fig. 6 and 7 are cross-sectional views of an electric field and a magnetic field inside the substrate integrated slow-wave air waveguide for improving the performance of the microwave passive device, and the lower dielectric plate concentrates the electric field to the middle air layer by metallizing through holes under the condition of not influencing the distribution of the magnetic field, so that the slow-wave effect is realized.

Fig. 8 is a graph of simulation results of S parameters of a substrate integrated slow wave air waveguide for improving the performance of a microwave passive device, in which the abscissa represents frequency and the ordinate represents amplitude, and in the case that the thicknesses of the middle dielectric plate and the lower dielectric plate are the same, the return loss of the waveguide is greater than 18dB, and the higher the frequency is, the lower the return loss is caused by the gradual mismatch of input ports.

Fig. 9 is a graph of the results of S-parameter simulation and testing of the fourth order filter, in which the abscissa represents frequency and the ordinate represents amplitude. The center frequency of a fourth-order filter designed by utilizing the substrate integrated slow wave air waveguide is 11.22GHz, the relative bandwidth is 7.6%, the return loss is more than 20dB, the insertion loss simulation value is less than 0.88dB, the test value is less than 1.2dB, and the error mainly lies in the process loss of joint welding. The insertion loss of the substrate integrated waveguide fourth-order filter with the same working frequency band is 2dB, and the insertion loss of the substrate integrated slow wave waveguide fourth-order filter with the same working frequency band is up to 3.2 dB. The size of the substrate integrated air waveguide fourth-order filter with the same working frequency band is 14.29cm²The actual size of the substrate integrated slow wave air waveguide fourth-order filter is 9cm²The equivalent ratio is reduced by 37%, and the combination of compact structure, low loss and high Q value is realized.

The substrate integrated slow wave air waveguide is a substrate integrated slow wave air waveguide improved by a substrate integrated air waveguide. The improved bottom dielectric layer forms a slow wave effect in the waveguide by opening uniform and dense metalized through holes, and concentrates an electric field in a middle air layer under the condition of not changing the distribution of a magnetic field, so that the transverse and longitudinal dimensions of the waveguide are reduced while the high Q value is kept, and finally the combination of the high Q value and miniaturization is realized.

The invention can realize the slow wave effect and the low-loss transmission of the waveguide on the basis of the three-layer structure of the substrate integrated hollow waveguide, obviously reduces the size of the substrate integrated hollow waveguide and is easier for the integration of a planar circuit compared with the substrate integrated hollow waveguide of the same technology, greatly increases the Q value and reduces the insertion loss compared with the substrate integrated slow wave waveguide of the same technology, and has better practicability.

By utilizing the waveguide structure, the invention designs the substrate integrated slow wave air waveguide four-order filter for improving the performance of a microwave passive device, has low insertion loss, high Q value and relatively reduced size, and fully shows the excellent characteristics of the waveguide structure. Compared with the substrate integrated air waveguide of the same technology, the invention realizes the coexistence of high Q value and miniaturization, is easy to process and has compact structure, and has wide application prospect in microwave circuits and systems with strict requirements in various aspects such as miniaturization, high Q value, low loss and the like.

The invention has various embodiments, and all technical solutions formed by adopting equivalent transformation or equivalent transformation are within the protection scope of the invention.