Quasi-planar dielectric resonator filter based on electromagnetic bandgap shield structure

Abstract

This invention discloses a quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure. It features equivalent artificial magnetic and electrical surfaces, resulting in an electromagnetic bandgap effect within the filter. This effect blocks the propagation of electromagnetic waves with wavelengths greater than one-quarter of the distance between the two surfaces. When the dielectric patch resonator is operating, only a small distance between the electrical and artificial magnetic surfaces is required to achieve broadband electromagnetic shielding. Therefore, the profile of the quasi-planar dielectric resonator filter can be made very low, making it easy to implement using multilayer printed circuit technology. Since the dielectric patch resonator is thin, it can be placed between upper and lower dielectric substrates, facilitating integration into multilayer planar circuits. Thus, the quasi-planar dielectric resonator filter offers advantages such as low profile and high integration density, resulting in low production costs. This invention has wide applications in the field of wireless communication technology.

Description

Technical Field

[0001] This embodiment relates to the field of wireless communication technology, and in particular to a quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure. Background Technology

[0002] The radio frequency (RF) front-end of satellite and base station communication systems places extremely high demands on the performance, size, and thermal stability of components. Bandpass filters, as essential and numerous passive components in the RF front-end, must meet these three requirements. Traditional planar filters, represented by microstrip lines, coplanar waveguides, and substrate-integrated waveguides, as well as stereo filters, represented by metal cavities, cannot simultaneously meet all three requirements. Dielectric resonators, with their advantages of low temperature drift coefficient, high quality factor, and small size, are widely used in filters for satellite and base station RF front-ends.

[0003] Existing dielectric resonator filters typically consist of three parts: a dielectric resonator, a metal shielding cavity, and a support pillar. The dielectric resonator is usually a circular or square dielectric block made of a ceramic material with high dielectric constant and low dielectric loss. The dielectric resonator is placed at the center inside the metal shielding cavity, with a low-dielectric-constant dielectric material serving as a support pillar at its bottom. This approach has three drawbacks. First, both the dielectric resonator itself and the metal shielding cavity have high profiles, making integration with other planar circuits difficult. Second, practical dielectric resonator filters usually contain multiple resonant cavities, each requiring a dielectric resonator and a support pillar. This means that multiple dielectric resonators and support pillars need to be manufactured, positioned, and assembled separately in actual production, leading to high filter manufacturing costs. Third, practical dielectric resonator filters often require the combination of various coupling structures with different properties, such as metal probes and metal coupling windows. The manufacturing and assembly processes for different coupling structures are separate, which also contributes to high production costs. Therefore, while existing dielectric resonator filters can meet the performance, size, and thermal stability requirements of RF front-ends, they suffer from high profiles and high production costs. Summary of the Invention

[0004] To address the technical problems of high profile and high production cost of current dielectric resonator filters, the purpose of this embodiment is to provide a quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure.

[0005] This invention includes a quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure.

[0006] An electromagnetic bandgap shielding structure is provided; the electromagnetic bandgap shielding structure includes a lower dielectric substrate, a supporting dielectric substrate, and an upper dielectric substrate; the upper surface of the supporting dielectric substrate has a rectangular hollow area; the upper surface of the upper dielectric substrate is provided with a second metal ground layer, and the lower surface of the upper dielectric substrate is printed with a mushroom-shaped metal structure, which is electrically connected to the second metal ground layer through a metal via.

[0007] Dielectric patch resonator; the dielectric patch resonator is in the form of a chip, the dielectric resonator is attached to the upper surface of the lower dielectric substrate, and the dielectric resonator is located within the rectangular cutout area;

[0008] The lower surface of the upper dielectric substrate is placed on the upper surface of the supporting dielectric substrate.

[0009] Furthermore, the dielectric patch resonator includes a first dual-mode resonant cavity, a second dual-mode resonant cavity, and a connecting rib, wherein the first dual-mode resonant cavity and the second dual-mode resonant cavity are connected by the connecting rib.

[0010] Furthermore, the first dual-mode resonant cavity is provided with a first chamfer, and the second dual-mode resonant cavity is provided with a second chamfer, wherein the first chamfer, the second chamfer, and the connecting rib are located on the same side of the dielectric patch resonator.

[0011] Furthermore, the upper surface of the lower dielectric substrate is provided with a first microstrip line and a second microstrip line, one end of the first microstrip line is located within the projection of the first dual-mode resonant cavity, and one end of the second microstrip line is located within the projection of the second dual-mode resonant cavity.

[0012] Furthermore, the mushroom-shaped metal structure is a metal patch array, which includes a cross-shaped metal patch and multiple rectangular metal patches, with each rectangular metal patch periodically distributed around the periphery of the cross-shaped metal patch;

[0013] The upper dielectric substrate is provided with a metal via array, which includes a plurality of metal vias. The position of each metal via corresponds to a corresponding cross-shaped metal patch or a rectangular metal patch. The metal vias are used to electrically connect the corresponding cross-shaped metal patch or rectangular metal patch to the second metal ground layer.

[0014] The projection of the cross-shaped metal patch is located between the first dual-mode resonant cavity and the second dual-mode resonant cavity.

[0015] Furthermore, the cross-shaped metal patch includes horizontal branch lines and vertical branch lines, and the horizontal branch lines intersect with the vertical branch lines.

[0016] Furthermore, the transverse branch line is parallel to the connecting rib, and the transverse branch line is orthogonal to the longitudinal branch line.

[0017] Furthermore, a first metal ground layer is provided on the lower surface of the lower dielectric substrate.

[0018] Furthermore, the dielectric patch resonator is made of a ceramic material with low loss and high dielectric constant.

[0019] Furthermore, both the upper dielectric substrate and the lower dielectric substrate are made of Rogers RT / Duroid 5880 material, and the supporting dielectric substrate is made of 4003c material.

[0020] The beneficial effects of this embodiment are as follows: In the quasi-planar dielectric resonator filter based on the electromagnetic bandgap shielding structure in this embodiment, the lower surface of the upper dielectric substrate in the electromagnetic bandgap shielding structure is printed with a mushroom-shaped metal structure. Therefore, the lower surface of the upper dielectric substrate is equivalent to an artificial magnetic surface, while the first metal ground on the upper surface of the lower dielectric substrate is equivalent to an electric surface. Thus, an electromagnetic bandgap effect is formed in the region between the parallel artificial magnetic surface and the electric surface. The electromagnetic bandgap effect can prohibit the propagation of electromagnetic waves with wavelengths greater than one-quarter of the distance between the two surfaces in the region between the two surfaces, thereby improving the performance of the dielectric patch resonator during operation. It can achieve the effect of energy shielding, and only requires a very small distance between the electric surface and the artificial magnetic surface to achieve a wide-band electromagnetic shielding effect. Therefore, the profile of the quasi-planar dielectric resonator filter can be made very low, and it is easy to realize through multilayer printed circuit technology. The dielectric chip resonator is thin, and its thickness is comparable to that of a conventional dielectric substrate, much smaller than a quarter wavelength of the operating frequency band. Therefore, it can be easily placed between the upper and lower dielectric substrates and is easy to integrate into multilayer planar circuits. Therefore, the quasi-planar dielectric resonator filter has the advantages of low profile and high integration, thus achieving low production cost. Attached Figure Description

[0021] Figure 1 This is an exploded view of the quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure in the embodiment.

[0022] Figure 2 This is a combined structure diagram of a quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure in the embodiment;

[0023] Figure 3 This is a cross-sectional view of the quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure in the embodiment.

[0024] Figure 4 This is a schematic diagram of the operating mode of the quasi-planar dielectric resonator filter in the embodiment;

[0025] Figure 5 This is a schematic diagram of the simulation test results of the quasi-planar dielectric resonator filter in the embodiment.

[0026] Reference numerals: 1011—Lower dielectric substrate, 10111—First microstrip line, 10112—Second microstrip line, 10113—First metal ground layer, 1013—Supporting dielectric substrate, 10131—Knock-out area, 1012—Upper dielectric substrate, 10121—Metal patch array, 10123—Second metal ground layer, 10124—Metal via array, 101221—Horizontal branch line, 101222—Vertical branch line, 1021—First dual-mode resonant cavity, 10211—First chamfer, 1022—Connecting rib, 1023—Second dual-mode resonant cavity, 10231—Second chamfer. Detailed Implementation

[0027] In this embodiment, the exploded view of the quasi-planar dielectric resonator filter based on the electromagnetic bandgap shielding structure is as follows: Figure 1 As shown. (Refer to...) Figure 1 The quasi-planar dielectric resonator filter consists of two main parts: an electromagnetic bandgap shielding structure and a dielectric patch resonator. The electromagnetic bandgap shielding structure includes components such as a lower dielectric substrate 1011, a supporting dielectric substrate 1013, and an upper dielectric substrate 1012.

[0028] Reference Figure 1 The upper surface of the supporting dielectric substrate 1013 has a rectangular hollow area 10131. The lower surface of the lower dielectric substrate 1011 is provided with a first metal ground layer 10113. The upper surface of the upper dielectric substrate 1012 is provided with a second metal ground layer 10123. The lower surface of the upper dielectric substrate 1012 is printed with a mushroom-shaped metal structure. The mushroom-shaped metal structure is electrically connected to the second metal ground layer 10123 through metal vias.

[0029] Reference Figure 1 The dielectric patch resonator is a thin sheet that is attached to the upper surface of the lower dielectric substrate 1011 and located within the rectangular cutout area 10131.

[0030] Reference Figure 1 The lower surface of the upper dielectric substrate 1012 is placed on the upper surface of the supporting dielectric substrate 1013.

[0031] In this embodiment, the lower dielectric substrate 1011 is made of Rogers RT / Duroid 5880 material with a thickness of 0.508 mm and a dielectric constant of 2.2; the upper dielectric substrate 1012 is made of Rogers RT / Duroid 5880 material with a thickness of 1.575 mm and a dielectric constant of 2.2; and the supporting dielectric substrate 1013 is made of 4003c material with a thickness of 0.813 mm and a dielectric constant of 3.38.

[0032] In this embodiment, refer to Figure 1 The dielectric patch resonator includes three parts: a first dual-mode resonant cavity 1021, a second dual-mode resonant cavity 1023, and a connecting rib 1022. The first dual-mode resonant cavity 1021 and the second dual-mode resonant cavity 1023 are connected by the connecting rib 1022.

[0033] In this embodiment, refer to Figure 1 The first dual-mode resonant cavity 1021 has a first chamfer 10211, and the second dual-mode resonant cavity 1023 has a second chamfer 10231. Specifically, the first dual-mode resonant cavity 1021 can be considered as a complete rectangular plate, while... Figure 1 A portion is cut off from the upper left corner of the first dual-mode resonator 1021, forming a first chamfer 10211. Similarly, the second dual-mode resonator 1023 can be initially considered as a complete rectangular plate, while... Figure 1 A portion of the upper right corner of the second dual-mode resonant cavity 1023 is cut off, and the cut-off portion forms the second chamfer 10231.

[0034] In this embodiment, refer to Figure 1 The first chamfer 10211, the second chamfer 10231 and the connecting rib 1022 are located on the same side of the dielectric patch resonator. That is, one end of the connecting rib 1022 is connected to the upper right corner of the first dual-mode resonator 1021, and the other end of the connecting rib 1022 is connected to the upper left corner of the second dual-mode resonator 1023.

[0035] In this embodiment, the dielectric patch resonator is made of a ceramic material with low loss and high dielectric constant. Specifically, the first dual-mode resonant cavity 1021, the second dual-mode resonant cavity 1023, and the connecting rib 1022 in the dielectric patch resonator can be manufactured using a ceramic material with a dielectric constant of 20.5. The tangent loss angle of the ceramic material is 0.0001, and the thickness is 0.6 mm. Since the thickness of the supporting dielectric substrate 1013 (0.813 mm) is greater than the thickness of the dielectric patch resonator (0.6 mm), the depth of the rectangular cutout region 10131 within the supporting dielectric substrate 1013 is greater than the thickness of the dielectric patch resonator, allowing the dielectric patch resonator to be completely placed within the rectangular cutout region 10131.

[0036] In this embodiment, the mushroom-shaped metal structure printed on the lower surface of the upper dielectric substrate 1012 is specifically a metal patch array 10121. (Refer to...) Figure 1 The metal patch array 10121 consists of a cross-shaped metal patch and multiple rectangular metal patches. The cross-shaped metal patch is located at the center of the lower surface of the upper dielectric substrate 1012, and the rectangular metal patches are periodically distributed around the cross-shaped metal patch. Specifically, a Cartesian coordinate system can be established with the location of the cross-shaped metal patch as the origin, and multiple points with integer coordinates can be selected in the Cartesian coordinate system. The rectangular metal patches are arranged at the locations of these points.

[0037] In this embodiment, refer to Figure 1 The upper dielectric substrate 1012 is provided with a metal via array 10124 consisting of multiple metal vias, one of which corresponds to a cross-shaped metal patch, and the other metal vias each correspond to a rectangular metal patch. Specifically, each metal via is aligned with its corresponding cross-shaped or rectangular metal patch, that is, the projection of each metal via coincides with its corresponding cross-shaped or rectangular metal patch. Each metal via penetrates the upper dielectric substrate 1012, thereby electrically connecting the cross-shaped metal patch to the second metal ground layer 10123 on the upper surface of the upper dielectric substrate 1012, and electrically connecting the rectangular metal patch to the second metal ground layer 10123 on the upper surface of the upper dielectric substrate 1012.

[0038] In this embodiment, the overall structure diagram of the quasi-planar dielectric resonator filter after assembly of all components is shown below. Figure 2 As shown, the cross-sectional view is as follows Figure 3 As shown. (Refer to...) Figure 2 The cross-shaped metal patch can be placed at the center of the lower surface of the upper dielectric substrate 1012, and the dielectric patch resonator can be placed at the center of the upper surface of the lower dielectric substrate 1011, so that the projection of the cross-shaped metal patch is located between the first dual-mode resonant cavity 1021 and the second dual-mode resonant cavity 1023.

[0039] In this embodiment, refer to Figure 1 and Figure 2 The cross-shaped metal patch consists of horizontal branch lines 101221 and vertical branch lines 101222, which intersect. Specifically, refer to... Figure 2 and Figure 3The orientation of the cross-shaped metal patch can be set so that the horizontal branch line 101221 in the cross-shaped metal patch is parallel to the connecting rib 1022 in the dielectric patch resonator, while the horizontal branch line 101221 is perpendicular to the vertical branch line 101222, that is, the horizontal branch line 101221 is parallel to the gap between the first dual-mode resonator 1021 and the second dual-mode resonator 1023.

[0040] In this embodiment, refer to Figure 1 and Figure 2 The upper surface of the lower dielectric substrate 1011 is provided with a first microstrip line 10111 and a second microstrip line 10112. The beginning of the first microstrip line 10111 and the beginning of the second microstrip line 10112 can be located at the edge of the upper surface of the lower dielectric substrate 1011, while the end of the first microstrip line 10111 extends to the bottom of the first dual-mode resonator, and the end of the second microstrip line 10112 extends to the bottom of the second dual-mode resonator. That is, the end of the first microstrip line 10111 is located within the projection of the first dual-mode resonant cavity 1021, and the end of the second microstrip line 10112 is located within the projection of the second dual-mode resonant cavity 1023.

[0041] In this embodiment, the first microstrip line 10111 and the second microstrip line 10112 can serve as feed lines. That is, when using a quasi-planar dielectric resonator filter, the quasi-planar dielectric resonator filter is fed through the first microstrip line 10111 and the second microstrip line 10112. Specifically, the beginning of the first microstrip line 10111 can be used as port 1 of the quasi-planar dielectric resonator filter, and the beginning of the second microstrip line 10112 can be used as port 2 of the quasi-planar dielectric resonator filter.

[0042] In this embodiment, the working principle of the quasi-planar dielectric resonator filter based on the electromagnetic bandgap shielding structure is as follows:

[0043] Because the lower surface of the upper dielectric substrate 1012 in the electromagnetic bandgap shielding structure is printed with a mushroom-shaped metal structure, the lower surface of the upper dielectric substrate 1012 is equivalent to an artificial magnetic surface, while the first metal ground on the upper surface of the lower dielectric substrate 1011 is equivalent to an electric surface. Therefore, the region between the parallel artificial magnetic surface and the electric surface forms an electromagnetic bandgap effect. This electromagnetic bandgap effect can prevent the propagation of electromagnetic waves with wavelengths greater than one-quarter of the distance between the two surfaces, thus achieving an energy shielding effect when the dielectric patch resonator is working. According to the shielding principle, only... Wideband electromagnetic shielding can be achieved with a very small distance between the electrical and artificial magnetic surfaces. Since the distance between the electrical and artificial magnetic surfaces is roughly equivalent to the cross-section of a quasi-planar dielectric resonator filter, the cross-section of the quasi-planar dielectric resonator filter can be made very low, making it easy to implement using multilayer printed circuit technology. The dielectric patch resonator is thin, with a thickness comparable to that of a conventional dielectric substrate, much smaller than a quarter wavelength of the operating frequency band. Therefore, it can be easily placed between the upper dielectric substrate 1012 and the lower dielectric substrate 1011. This characteristic makes it easy to integrate into multilayer planar circuits. These characteristics give the quasi-planar dielectric resonator filter based on the electromagnetic bandgap shielding structure in this embodiment the advantages of low cross-section and high integration. High integration facilitates mass production, thereby achieving low production costs.

[0044] Based on the above working principle, by using a monolithically designed dielectric patch resonator, that is, by connecting two dual-mode dielectric resonant cavities together through connecting rib 1022, the two resonant cavities can be manufactured, positioned and assembled simultaneously, effectively saving production costs. The coupling structure of each mode of the dielectric patch resonator filter can be achieved by printing cross-shaped metal patches on the lower surface of the upper dielectric substrate 1012, while the input and output structure is achieved by printing microstrip lines on the upper surface of the lower dielectric substrate 1011. That is, all coupling structures can be completed by printed circuit technology, further saving production costs. In addition, thanks to the flexibility of printed circuit technology, the shape of the coupling structure can be flexibly designed according to requirements.

[0045] In this embodiment, refer to Figure 4 When the quasi-planar dielectric resonator filter is working, refer to Figure 4 The first dual-mode resonant cavity 1021 is fed through ports 1 and 2 to align with the planar dielectric resonator filter. It operates in the first degenerate mode 201, which includes a first TM mode. 11 I Model 2011 and First TM 11 II Mode 2012, the second dual-mode resonator 1023 operates in the second degenerate mode 202, the second degenerate mode includes the second TM 11 IMod 2021 and Second TM 11 II Mod 2022. First microstrip line 10111 and first TM 11 II Mode 2012 coupling, second microstrip line 10112 and second TM 11 II Modulus 2022 coupling.

[0046] With the first dual-mode resonant cavity 1021 having a first chamfer 10211 and the second dual-mode resonant cavity 1023 having a second chamfer 10231, refer to Figure 5 First TM 11 I Model 2011 and First TM 11 II Module 2012 is coupled through the first chamfer 10211, and the second TM 11 I Mod 2021 and Second TM 11 II Module 2022 is coupled through the second chamfer 10231, the first TM 11 I Model 2011 and Second TM 11 I Module 2021 is coupled through lateral branch lines 101221, the first TM 11 II Model 2012 and Second TM 11 II Module 2022 is coupled through longitudinal branch line 101222.

[0047] according to Figure 4 It can be seen that the dielectric patch resonator filter composed of two dual-mode dielectric resonator cavities is a fourth-order filter. Each cavity operates in a pair of degenerate modes, resulting in a total of four coupling paths, among which the first TM... 11 II Model 2012 and Second TM 11 II The coupling between modes is a cross-coupling path, while the remaining coupling paths are main coupling paths. This topology can introduce two transmission zeros on both sides of the passband, thereby improving the selectivity of the passband.

[0048] Figure 5 To simulate and test the quasi-planar dielectric resonator filter in this embodiment, the measured return loss and insertion loss versus frequency are plotted. The center operating frequency used in the simulation is 17.52 GHz. Figure 5 It can be seen that the 3dB passband relative bandwidth is 3.58%, the lowest insertion loss in the passband is 0.92dB, and the return loss in the passband is greater than 16dB, indicating that the quasi-planar dielectric resonator filter has good performance.

[0049] In summary, the quasi-planar dielectric resonator filter in this embodiment has the following advantages: no additional metal shielding cavity is required; the shielding structure and coupling structure can be fabricated using multilayer printed circuit technology; the thickness of the dielectric patch resonator is similar to that of the dielectric substrate; the overall profile of the filter is low, and it has a quasi-planar structure, which can be directly applied to multilayer planar circuit boards; multiple dielectric resonator cavities are connected into a monolithic structure by connecting ribs, so that the manufacturing, positioning and assembly of all resonators can be completed in one go, resulting in low production costs.

[0050] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "up," "down," "left," and "right" used in this disclosure are only relative to the relative positional relationships of the components of this disclosure in the accompanying drawings. The singular forms "a," "an," and "the" used in this disclosure are also intended to include the plural forms, unless the context clearly indicates otherwise. Moreover, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this embodiment specification is only for describing specific embodiments and is not intended to limit the embodiments. The term "and / or" as used in this embodiment includes any combination of one or more of the associated listed items.

[0051] It should be understood that although the terms first, second, third, etc., may be used to describe various elements in this disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, a first element may also be referred to as a second element without departing from the scope of this disclosure, and similarly, a second element may also be referred to as a first element. The use of any and all instances or exemplary language (“e.g.,” “such as,” etc.) provided in this embodiment is intended only to better illustrate the embodiments in this embodiment and, unless otherwise required, does not impose a limitation on the scope of this embodiment.

[0052] The above are merely preferred embodiments in this embodiment. This embodiment is not limited to the above-described implementation methods. As long as the same means are used to achieve the technical effects of this embodiment, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this embodiment should be included within the scope of protection of this embodiment. Within the scope of protection of this embodiment, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. A quasi-planar dielectric resonator filter based on an electromagnetic bandgap shielding structure, characterized in that, The quasi-planar dielectric resonator filter includes: An electromagnetic bandgap shielding structure is provided; the electromagnetic bandgap shielding structure includes a lower dielectric substrate, a supporting dielectric substrate, and an upper dielectric substrate; the upper surface of the supporting dielectric substrate has a rectangular hollow area; the upper surface of the upper dielectric substrate is provided with a second metal ground layer, and the lower surface of the upper dielectric substrate is printed with a mushroom-shaped metal structure, which is electrically connected to the second metal ground layer through a metal via. A dielectric surface mount resonator; the dielectric surface mount resonator is in the form of a plate, and is attached to the upper surface of the lower dielectric substrate, and is located in the cutout area; the dielectric surface mount resonator includes a first dual-mode resonant cavity, a second dual-mode resonant cavity, and a connecting rib, and the first dual-mode resonant cavity and the second dual-mode resonant cavity are connected by the connecting rib; The lower surface of the upper dielectric substrate is placed on the upper surface of the supporting dielectric substrate; The mushroom-shaped metal structure is a metal patch array, which includes a cross-shaped metal patch and multiple rectangular metal patches. The rectangular metal patches are periodically distributed around the cross-shaped metal patch. The upper dielectric substrate is provided with a metal via array, which includes a plurality of metal vias. The position of each metal via corresponds to a corresponding cross-shaped metal patch or a rectangular metal patch. The metal vias are used to electrically connect the corresponding cross-shaped metal patch or rectangular metal patch to the second metal ground layer. The projection of the cross-shaped metal patch is located between the first dual-mode resonant cavity and the second dual-mode resonant cavity.

2. The quasi-planar dielectric resonator filter according to claim 1, characterized in that, The first dual-mode resonant cavity has a first chamfer, and the second dual-mode resonant cavity has a second chamfer, wherein the first chamfer, the second chamfer, and the connecting rib are located on the same side of the dielectric patch resonator.

3. The quasi-planar dielectric resonator filter according to claim 2, characterized in that, The upper surface of the lower dielectric substrate is provided with a first microstrip line and a second microstrip line. One end of the first microstrip line is located within the projection of the first dual-mode resonant cavity, and one end of the second microstrip line is located within the projection of the second dual-mode resonant cavity.

4. The quasi-planar dielectric resonator filter according to claim 1, characterized in that, The cross-shaped metal patch includes horizontal branch lines and vertical branch lines, and the horizontal branch lines intersect with the vertical branch lines.

5. The quasi-planar dielectric resonator filter according to claim 4, characterized in that, The transverse branch line is parallel to the connecting rib, and the transverse branch line is orthogonal to the longitudinal branch line.

6. The quasi-planar dielectric resonator filter according to claim 1, characterized in that, The lower surface of the lower dielectric substrate is provided with a first metal ground layer.

7. The quasi-planar dielectric resonator filter according to claim 1, characterized in that, The dielectric patch resonator is made of a ceramic material with low loss and high dielectric constant.

8. The quasi-planar dielectric resonator filter according to claim 1, characterized in that, Both the upper dielectric substrate and the lower dielectric substrate are made of Rogers RT / Duroid 5880 material, and the supporting dielectric substrate is made of 4003c material.

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