Substrate integrated dielectric resonator and antenna
Technical Field
the invention relates to the field of communication, in particular to a substrate integrated dielectric resonator and an antenna.
background
Referring to fig. 1, a conventional dielectric resonator is separately manufactured using a high dielectric constant, low loss ceramic material, and a feeding circuit thereof is additionally manufactured and, during assembly, the two are bonded using a dielectric paste. The assembly mode has low efficiency and large error, and particularly, the dielectric resonator antenna with high frequency has small size, large assembly error and relatively low yield.
Disclosure of Invention
The invention aims to solve the technical problems of low processing and assembling efficiency and large error in the prior art, and provides a substrate integrated dielectric resonator and an antenna.
The technical scheme adopted by the invention for solving the technical problems is as follows: constructing a substrate integrated dielectric resonator, which comprises a plurality of parts formed by hollowing out a dielectric substrate, wherein the plurality of parts comprise N rectangular parts, hollow-out areas are arranged between two long sides of each rectangular part and other parts, and the two short sides of each rectangular part are connected with the other parts;
Each rectangular part is provided with a plurality of rows of metalized through holes so as to divide the whole rectangular part into M rectangular resonator units distributed along the rectangular part, the length of the long side of each resonator unit is greater than 1.5 times that of the short side, and the working mode electric field of each resonator unit is perpendicular to the long side;
Wherein M, N are all positive integers of 1 or more.
preferably, a row of the metalized through holes is respectively formed at the junctions of the two short sides of the rectangular part and the other parts.
Preferably, the N rectangular portions are parallel to each other.
Preferably, the plurality of portions further have a ring-shaped portion in the shape of a rectangular ring, and the N rectangular portions are connected between a pair of side edges of the ring-shaped portion.
Preferably, the rectangular portion is parallel to the other pair of sides of the annular portion.
Preferably, two rows of the metalized via holes are formed in the rectangular portion, and the two rows of the metalized via holes are respectively located at the junction of the two short sides of the rectangular portion and the annular portion.
Preferably, M is an even number, the M rectangular resonator units are divided into two groups, a certain distance is left between the two groups of rectangular resonator units, each group of rectangular resonator units includes M/2 rectangular resonator units, and the M/2 rectangular resonator units in the same group are formed by M/2+1 rows of the metalized via holes at intervals.
The invention also constructs a substrate integrated dielectric resonator antenna which is formed by laminating a plurality of layers of dielectric substrates, the plane projections of the plurality of layers of dielectric substrates are overlapped, and the topmost layer of dielectric substrate is hollowed out to form the substrate integrated dielectric resonator.
furthermore, the topmost dielectric substrate and the metal ground on the upper surface of the dielectric substrate below the topmost dielectric substrate are bonded through the prepreg.
The substrate integrated dielectric resonator and the antenna have the following beneficial effects: in the invention, a dielectric substrate is utilized to form at least one resonator unit through hollow design and metallized via holes, the size of each resonator unit satisfies that the long side is more than 1.5 times of the short side, the field intensity of the edge of a working mode in the x direction can be ignored, and the metallized via holes are loaded on the short side, namely, a metal wall is loaded on the edge, namely, the original magnetic wall is changed into an electric wall, the electromagnetic field distribution of the working mode is not influenced, the resonant frequency of the electromagnetic field distribution is not changed, and the addition of the metal wall can block certain parasitic modes in the resonator unit, so that the performance of the antenna is ensured. The yield is improved, and the self-packaging characteristic is achieved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts:
Fig. 1 is an exploded view of a prior art isolated dielectric resonator antenna;
FIG. 2 is a schematic diagram of the electric field distribution of the primary mode of an isolated grounded dielectric resonator;
FIG. 3 is a graph of the trend of isolated grounded dielectric resonator mode and mode frequency with dimension b in the x-direction;
FIG. 4 is a graph of the electric field distribution for isolated grounded dielectric resonator modes at different dimensions in the x-direction;
FIG. 5 is a schematic diagram of the evolution of a dielectric resonator integrated from isolation to substrate;
Fig. 6 is an exploded view of a first embodiment of a substrate integrated dielectric resonator antenna of the present invention;
FIG. 7 is a diagram illustrating simulation results of reflection coefficient and gain according to the first embodiment;
FIG. 8 is a diagram showing simulation results of patterns according to the first embodiment;
fig. 9 is an exploded view of a second embodiment of the substrate integrated dielectric resonator antenna of the present invention;
FIG. 10 is a top perspective view of a second embodiment of the present invention;
FIG. 11 is a bottom perspective view of a second embodiment of the present invention;
FIG. 12 is a diagram showing simulation results of reflection coefficient and gain according to the second embodiment;
fig. 13 is a pattern diagram of the second embodiment.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Exemplary embodiments of the invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It should be understood that the embodiments and specific features in the embodiments of the present invention are described in detail in the present application, but not limited to the present application, and the features in the embodiments and specific features in the embodiments of the present invention may be combined with each other without conflict.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The idea of the invention is as follows: the traditional dielectric resonator has low processing and assembling efficiency and large error. Considering that the size of the device is small in the millimeter wave band, the dielectric resonator is processed based on the substrate integration technology, and is directly pressed with the feed circuit of the dielectric resonator through the multilayer PCB technology, so that the complexity of processing and assembly is greatly reduced, and the yield is improved. In combination with the alignment requirement between different layers in the PCB lamination technology, it is desirable to process the dielectric resonators on a monolithic dielectric substrate, and in combination with the antenna array, it is necessary to have a plurality of dielectric resonators in the same plane, and the connection between them is very important.
First, we list the electric field distribution of the main mode of the grounded dielectric resonator in fig. 2, where the main mode has a half-wavelength standing wave in the y-direction and uniform field distribution in the x-direction. The resonant frequency of the main mode of the dielectric resonator can be derived from the following equation:
k=π/a(2)
k=π/(2l)(3)
the above equations can be used to preliminarily determine the dimensions of the dielectric resonator, but since the derivation of the set of equations relies on the assumption of mixed magnetic walls, the accuracy of the equations decreases when the dimensions of the resonator fall within certain limits, as discussed below. The substrate we used to design the dielectric resonator was still Rogers 3010.635 mm thick, the initial value for the dielectric resonator size in question was 4 x 4mm2, and then parametric analysis was performed by increasing the size in a single direction.
the electric field distribution of the main mode of the grounded dielectric resonator with the square plane shape is listed in fig. 2 again, the electric field distribution of the main mode has half-wavelength standing waves along the y direction, and the electric field distribution is uniform along the x direction. And in addition, the two main mode resonators have the same frequency. As the dimension in the x direction increases, the two orthogonal modes begin to separate, and the mode frequency changes at a much slower rate than the modes, with a trend as shown in fig. 3. And the former tends to stabilize as the size in the x direction increases because when the size in the x direction is large enough, the intensity of the field at the edges of the mode in the x direction gradually decreases until it approaches zero, and the distribution of the electric field intensity at this moment is as shown in fig. 4. It can be seen that when b is 1.2a, the electric field strength at the x-direction edge of the dielectric resonator has been reduced to half the central field strength, i.e. 3dB attenuation compared to the maximum, with the edge field strength attenuating more as the x-direction dimension is further increased. Therefore, it can be considered that when the size in the x direction is larger than 1.5 times the size in the y direction, i.e. b is larger than or equal to 1.5a, the edge field strength can be ignored. At this time, the metal wall is loaded on the edge, as shown in fig. 5, that is, the original magnetic wall is changed into an electric wall, so that the electromagnetic field distribution of the mode is not influenced, and the resonant frequency of the mode is not changed. And the addition of the metal wall can block certain parasitic modes in the resonator, so that the performance of the antenna is ensured.
Based on the above analysis thought, the general thought of the invention is as follows: constructing a substrate integrated dielectric resonator, which comprises a plurality of parts formed by hollowing out a dielectric substrate, wherein the plurality of parts comprise N rectangular parts, hollow-out areas are arranged between two long sides of each rectangular part and other parts, and the two short sides of each rectangular part are connected with the other parts; the rectangular part is provided with a plurality of rows of metalized through holes so as to divide the whole rectangular part into M rectangular resonator units distributed along the rectangular part, the length of the long side of each resonator unit is greater than 1.5 times that of the short side, and the working mode electric field of each resonator unit is perpendicular to the long side of each resonator unit; wherein M, N are all positive integers of 1 or more.
The rectangular portions may be provided obliquely to the side edges of the entire dielectric substrate, or may be provided in parallel. In addition, the number of the rectangular portions may be one or more, and when the rectangular portion 12 is plural, the plural rectangular portions may be parallel to each other, or may not be parallel, as long as the arrangement of the resonator elements on the final rectangular portion is ensured to be satisfactory.
The following description will be made in detail by taking a specific embodiment of a two-substrate integrated dielectric resonator and an antenna composed of the same as an example.
Example one
Fig. 6 is an exploded view of a first embodiment of the substrate-integrated dielectric resonator antenna according to the present invention, and referring to fig. 1, it can be seen that the resonator elements in this embodiment are not isolated, and in this embodiment, M is 1, and N is 1.
Specifically, the substrate integrated dielectric resonator antenna in this embodiment is formed by laminating multiple dielectric substrates 1, 2, and 3, and the laminated planar dimensions of the multiple dielectric substrates 1, 2, and 3 are the same, wherein the topmost dielectric substrate 1 is hollowed out to form the substrate integrated dielectric resonator of the present invention, and as shown in 100 in the figure, the substrate integrated dielectric resonator is a hollowed-out region.
the term "the same plane size" means that the edge profiles of the planar projections of the dielectric substrates 1, 2, and 3 are completely the same. For example, in the present embodiment, the edge profiles of the planar projection of the multilayer structure are all rectangular. In other words, the dielectric substrates 1, 2, and 3 of the present embodiment are rectangular plate-shaped structures with the same size, which can meet the alignment requirement between different layers in the PCB lamination technology, and can laminate the multilayer structures into a whole by the PCB lamination technology.
Especially in the millimeter wave band, considering that the size of the device is small, the traditional processing and assembly are very complex, but the embodiment can process the dielectric resonator based on the substrate integration technology, process the dielectric resonator on the whole dielectric substrate, and directly press the dielectric resonator with the feed circuit thereof through the multilayer PCB technology, which is beneficial to reducing the complexity of processing and assembly and improving the yield.
Specifically, the dielectric substrate 1 includes annular portions 11 and rectangular portions 12, a hollow area is formed between two long sides of each rectangular portion 12 and the adjacent annular portion 11, and two short sides of each rectangular portion 12 are connected to the annular portions 11.
In this embodiment, the annular portion 11 is a rectangular ring, the rectangular portion 12 is connected between a pair of sides of the annular portion 11, and the rectangular portion 12 is parallel to the other pair of sides of the annular portion 11, i.e. the whole substrate 1 is substantially hollow and designed to be "japanese".
two rows of metalized vias 101 are disposed on the rectangular portion 12 to divide the entire rectangular portion 12 into one rectangular resonator unit distributed along the rectangular portion 12, in this embodiment, the two rows of metalized vias 101 are respectively located at the boundary between two short sides of the rectangular portion 12 and the annular portion 11. The length b of the long side of the resonator unit is larger than 1.5 times of the length a of the short side, and the length a of the short side can be finely adjusted according to the design frequency. The mode of operation of the resonator element has an electric field perpendicular to its long sides. Specifically, the primary mode of the resonator unit is a mode, and the x-axis of the TE mode is parallel to the rectangular portion 12.
It should be noted that, in other embodiments, the rectangular portion 12 may be disposed obliquely with respect to the side of the annular portion 11. In addition, the number of the rectangular portions 12 may be larger, and when there are a plurality of rectangular portions 12, the plurality of rectangular portions 12 may or may not be parallel to each other, as long as the arrangement of the resonator elements on the final rectangular portion is ensured to meet the requirement. In addition, when there are a plurality of rectangular portions 12, a hollow area is also formed between two long sides of each rectangular portion 12 and the adjacent rectangular portion 12. In addition, the number of resonator elements on the rectangular portion 12 may be more, which are simple variations of the present embodiment and are within the scope of the present invention.
with continued reference to fig. 6, the lower surface of substrate 3 is provided with a metal ground 6, the upper surface of substrate 2 is provided with a metal ground 4, and a metal ground 5 is provided between the upper surface of substrate 3 and the lower surface of substrate 2. The substrate 3 is mainly used for designing a power distribution network to realize power feeding. The layer substrate 2 is primarily designed as a SIW cavity to couple signals to the resonator elements.
Referring to fig. 7-8, simulation results of the antenna of the present embodiment are shown, and it can be seen that the performance of the dielectric resonator antenna designed based on the substrate integration technology is almost unchanged, and this characteristic provides feasibility for processing the integrated dielectric resonator by using the substrate integration technology.
Example two
On the basis of the first embodiment, considering that a plurality of dielectric resonators are required to be in the same plane in an antenna array, the connection between the dielectric resonators is particularly important. For this reason, the present embodiment provides a substrate-integrated dielectric resonator antenna, and the present embodiment is the case where M is 4 and N is 1. Referring to fig. 9 and 10, a differential substrate integrated dielectric resonator antenna fed by 4 × 1 serial-parallel TE20 mode SIW is shown.
Similarly, the embodiment is also formed by laminating a multilayer structure, the metal ground 5 is provided with one coupling slot 501 parallel to the rectangular portion 12, the metal ground 4 is provided with four sets of coupling slots 401, each set of coupling slots 401 corresponds to one resonator unit, the coupling slots 401 are also parallel to the rectangular portion 12, the substrate 2 is provided with metal through holes 201 to form a TE20 mode SIW cavity, and the substrate 3 is provided with metal through holes 301 to form a TE10 mode SIW power divider. The signal can pass through a coupling gap 501 of a metal ground 5 above the TE10 mode SIW power divider to couple electromagnetic energy to a TE20 mode SIW cavity on the upper layer, so that the conversion from a TE10 mode to a TE20 mode is realized. And the pair of symmetric coupling slots 401 on the TE20 mode SIW cavity couples the differential TE20 mode electromagnetic energy to the substrate integrated resonator, thereby exciting the modes in the dielectric resonator.
Referring to fig. 9, the present embodiment differs from the first embodiment in that the number of resonator elements on the rectangular portion 12 is increased, as compared with fig. 6. In addition, the present embodiment is different from the first embodiment in that the third metal ground 4 is bonded to the lower surface of the top substrate 1 through the prepreg 7.
Specifically, M (M ═ 4) resonator units are formed in the rectangular portion 12. The M rectangular resonator elements are divided into two groups, and referring to fig. 9 and 10, 1a and 1b are a group of resonator elements, 2a and 2b are a group of resonator elements, and two adjacent groups of rectangular resonator elements are spaced by a certain distance. The M/2 (i.e. 2) rectangular resonator units in the same group are formed by M/2+1 rows (i.e. 3 rows) of metallized through holes 101 at intervals, i.e. in the same group, two adjacent rows of metallized through holes 101 form one rectangular resonator unit.
Of course, it will be appreciated that in other embodiments, the rectangular portion 12 may continue to expand into more sets of resonator elements. In addition, it should be noted that although only one rectangular portion 12 is provided in both embodiments of the present invention, actually, in other embodiments, there may be more rectangular portions 12.
In the embodiment, the feeding network design is performed in combination with the conversion of TE10 mode SIW and TE20 mode SIW, and the TE10 mode SIW with the width of a1 and the TE20 mode SIW with the width of a2 perform electromagnetic energy transmission through the coupling gap on the metal ground shared by the two. The TE20 mode has a transition of the coupling portion to the feeding portion, which is achieved by a change in SIW width from a2 to a3, ensuring impedance matching with each other, with specific dimensions as shown in table 1.
TABLE 1 resonator antenna dimensions
Size (mm) |
a
|
b
|
c
|
ls1
|
ws1
|
a1
|
a2
|
a3
|
Parameter value |
3.9
|
7.1
|
5.3
|
3.5
|
0.5
|
4.4
|
7.4
|
10.8
|
Size (mm) |
dd
|
px
|
py
|
ls2
|
ws2
|
ds
|
ps
|
|
Parameter value |
1.7
|
3.6
|
0.6
|
2.5
|
0.5
|
2.6
|
5.3
|
|
the simulated reflection coefficient and gain of the antenna and the radiation patterns of 26.5GHz, 28GHz and 29.5GHz refer to FIGS. 12 and 13. It can be seen that the antenna array has a frequency range of 26.5-29.5GHz of | S11| < -10dB, and covers the 28GHz frequency band of 5G communication. The maximum value of the in-band gain reaches 12.15dBi, the 3dB gain bandwidth is 25.8-29.6GHz, the in-band gain is flat, the in-band directional diagram has good symmetry, and the cross polarization is lower than-40 dB.
In summary, the substrate integrated dielectric resonator and the antenna of the invention have the following beneficial effects: in the invention, a dielectric substrate is utilized to form at least one resonator unit through hollow design and metallized via holes, the size of each resonator unit satisfies that the long side is more than 1.5 times of the short side, the field intensity of the edge of a working mode in the x direction can be ignored, and the metallized via holes are loaded on the short side, namely, a metal wall is loaded on the edge, namely, the original magnetic wall is changed into an electric wall, the electromagnetic field distribution of the working mode is not influenced, the resonant frequency of the electromagnetic field distribution is not changed, and the addition of the metal wall can block certain parasitic modes in the resonator unit, so that the performance of the antenna is ensured. The yield is improved, and the self-packaging characteristic is achieved.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.