Filtering antenna and electronic device

Abstract

A filtering antenna and an electronic device, which belong to the technical field of antennas. The filtering antenna comprises a grounding layer (GNDL), a first dielectric layer (ILDA), a second dielectric layer (ILDB) and a radiation patch (RP), which are sequentially stacked, and also comprises a coupling probe (PRB), wherein the coupling probe (PRB) comprises a microstrip line (PRB1) sandwiched between the first dielectric layer (ILDA) and the second dielectric layer (ILDB), and also comprises a feed member (PRB2) penetrating the first dielectric layer (ILDA); the microstrip line (PRB1) comprises a primary line (PA) and an open-circuited branch line connected to the primary line (PA); the feed member (PRB2) is electrically connected to the primary line (PA); the distance between a feed center of the microstrip line (PRB1) and a first end of the primary line (PA) is D1; and the distance between the first end of the primary line (PA) and the orthographic projection of an edge (RPE) of the radiation patch on the second dielectric layer (ILDB) is D4, wherein 2.5≤D1 / D4≤3.0. The filtering antenna can simultaneously realize radiation and filtering functions.

Description

Filter antennas and electronic devices Technical Field

[0001] The present disclosure relates to the field of antenna technology, and in particular to a filtering antenna and an electronic device. Background Art

[0002] With the development of the Internet of Things (IoT) and 5G mobile communications, wireless communication technologies and wireless smart devices are constantly evolving, dramatically improving people's quality of life. This has also led to a dramatic increase in the complexity of modern wireless communication systems, necessitating wireless communication systems that support multiple frequencies, standards, and formats. Research on the RF front-end of communication systems focuses on frequency-tunable and multifunctional devices and antennas, which are of great practical significance to the development of wireless communication systems.

[0003] Antenna-filter fusion design has been a hot research area in recent years. Filter antennas are antennas that can achieve both radiation and filtering functions. Common design methods include adding open / short-circuited branches, etching gaps, adding parasitic structures, and adding metal probes. Fusion designs eliminate both filtering and matching circuits, resulting in more compact filter antennas and lower losses. Filter antennas based on patch antenna design offer advantages such as compact structure, simple design, and low cost.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0005] Summary of the Invention

[0006] The purpose of the present disclosure is to overcome the above-mentioned deficiencies of the prior art and provide a filtering antenna and electronic equipment that simultaneously achieve radiation and filtering functions.

[0007] According to one aspect of the present disclosure, a filtering antenna is provided, comprising a ground layer, a first dielectric layer, a second dielectric layer, and a radiating patch stacked in sequence, and a coupling probe; the coupling probe comprises a microstrip line sandwiched between the first dielectric layer and the second dielectric layer, and a feeding element extending through the first dielectric layer; the microstrip line comprises a main line extending in a first direction and an open branch line connected to the main line; the feeding element is electrically connected to the main line; the distance between the feeding center of the microstrip line and the first end of the main line is D1; ​​the distance between the orthographic projection of the first end of the main line on the second dielectric layer and the orthographic projection of the edge of the radiating patch on the second dielectric layer is D4;

[0008] Among them, 2.5≤D1 / D4≤3.0.

[0009] According to one embodiment of the present disclosure, the width of the main line is greater than the width of the open branch line.

[0010] According to one embodiment of the present disclosure, the main line has a first symmetry axis along the first direction; the radiation patch has a second symmetry axis along the first direction;

[0011] The orthographic projection of the first symmetry axis on the radiation patch coincides with the second symmetry axis.

[0012] According to one embodiment of the present disclosure, the orthographic projection of the first end of the main line on the second dielectric layer is located within the orthographic projection range of the radiation patch on the second dielectric layer.

[0013] According to one embodiment of the present disclosure, the distance between the orthographic projection of the second end of the trunk line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D5;

[0014] Among them, D4<D5.

[0015] According to an embodiment of the present disclosure, the radius of the feeder is between 0.35 and 0.45 mm.

[0016] According to one embodiment of the present disclosure, the radiation patch is square with a side length between 13 and 17 mm.

[0017] According to one embodiment of the present disclosure, the length of the main line is between 15 and 17 mm.

[0018] According to one embodiment of the present disclosure, the open branch line includes a first branch line extending along the first direction and a second branch line extending along the second direction; the second direction is perpendicular to the first direction; the first end of the second branch line is connected to the main line, and the second end of the second branch line is connected to the first end of the first branch line, and the second end of the first branch line is located on a side of the second branch line close to the first end of the main line;

[0019] The length of the main line is L1, and the length of the first branch line is L2;

[0020] Among them, 2.0≤L1 / L2≤2.4.

[0021] According to one embodiment of the present disclosure, the second branch line has a first side of the second branch line and a second side of the second branch line that are arranged opposite to each other; in the first direction, the first side of the second branch line is located on a side of the second side of the second branch line that is close to the feeding center; the distance between the feeding center and the straight line on which the first side of the second branch line lies is D3, and the distance between the second end of the main line and the straight line on which the first side of the second branch line lies is X1;

[0022] Among them, D3 is basically equal to X1.

[0023] According to an embodiment of the present disclosure, in the first direction, the second end of the first branch line is located between the feeding center and the first end of the main line.

[0024] According to an embodiment of the present disclosure, in the first direction, the distance between the feeding center and the second end of the first branch line is D2;

[0025] Among them, D2<D3.

[0026] According to one embodiment of the present disclosure, the distance between the main line and the first branch line is X2;

[0027] Among them, X2 is smaller than D1.

[0028] According to one embodiment of the present disclosure, the open branch line also includes a third branch line; the third branch line has the same extension direction as the first branch line and is respectively arranged on both sides of the second branch line; the first end of the third branch line is connected to the second end of the second branch line; the orthographic projection of the second end of the third branch line on the second dielectric layer is located within the orthographic projection of the radiation patch on the second dielectric layer.

[0029] According to one embodiment of the present disclosure, the length of the third branch line is L2x; the distance between the orthographic projection of the second end of the third branch line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is X3;

[0030] Among them, X3<L2x.

[0031] According to an embodiment of the present disclosure, the open branch line further includes a fifth branch line extending along the second direction and a fourth branch line extending along the first direction;

[0032] The fourth branch line and the first branch line are respectively located on both sides of the main line; the first end of the fifth branch line is connected to the main line, and the second end of the fifth branch line is connected to the first end of the fourth branch line; the second end of the fourth branch line is located on the side of the first end of the fourth branch line close to the feeding center.

[0033] According to an embodiment of the present disclosure, a center line of the fifth branch line and a center line of the second branch line are located on the same straight line.

[0034] According to an embodiment of the present disclosure, the distance between the fourth branch line and the main line is X4; the distance between the first branch line and the main line is X2;

[0035] Among them, X2 and X4 are basically equal.

[0036] According to an embodiment of the present disclosure, the length of the first branch line is L2, and the length of the fourth branch line is L4;

[0037] Among them, L4<L2.

[0038] According to one embodiment of the present disclosure, the open branch line also includes a fifth branch line extending along the second direction and a fourth branch line extending along the first direction, and the fourth branch line and the first branch line are respectively located on both sides of the main line; the first end of the fifth branch line is connected to the main line, and the second end of the fifth branch line is connected to the first end of the fourth branch line; the second end of the fourth branch line is located on the side of the first end of the fourth branch line away from the feeding center.

[0039] According to an embodiment of the present disclosure, a center line of the fifth branch line and a center line of the second branch line are located on the same straight line.

[0040] According to an embodiment of the present disclosure, the distance between the fourth branch line and the main line is X4; the distance between the first branch line and the main line is X2;

[0041] Among them, X2 and X4 are basically equal.

[0042] According to one embodiment of the present disclosure, the orthographic projection of the second end of the fourth branch line on the second dielectric layer is located within the orthographic projection of the radiation patch on the second dielectric layer; the length of the fourth branch line is L4;

[0043] The distance between the orthographic projection of the second end of the fourth branch line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is X5;

[0044] Among them, X5<L4.

[0045] According to an embodiment of the present disclosure, the microstrip line further includes a sixth branch line extending along the first direction, and the sixth branch line and the open branch line are respectively located on both sides of the main line.

[0046] According to an embodiment of the present disclosure, the sixth branch line has a first end and a second end; the first end of the sixth branch line is close to the first end of the main line, and the second end of the sixth branch line is close to the second end of the main line;

[0047] In the first direction, the distance between the first end of the sixth branch line and the feeding center is D6;

[0048] Among them, D6<D1.

[0049] According to one embodiment of the present disclosure, the distance between the sixth branch line and the main line is D7;

[0050] The D7 is not greater than the radius of the feeding element.

[0051] According to an embodiment of the present disclosure, the length of the sixth branch line is L6; the length of the main line is L1;

[0052] Among them, L6<L1.

[0053] According to one embodiment of the present disclosure, the microstrip line also includes a seventh branch line extending along the second direction; the first end of the seventh branch line is connected to the sixth branch line, and the orthographic projection of the second end of the seventh branch line on the second dielectric layer is located outside the orthographic projection of the radiation patch on the second dielectric layer.

[0054] According to an embodiment of the present disclosure, the seventh branch line has a first side and a second side that are oppositely arranged; in the first direction, the first side of the seventh branch line is located on a side of the second side close to the feeding center;

[0055] The sixth branch line has a first end and a second end; the first end of the sixth branch line is close to the first end of the main line, and the second end of the sixth branch line is close to the second end of the main line; the distance between the first end of the sixth branch line and the first side of the seventh branch line is X6, and the distance between the second end of the sixth branch line and the first side of the seventh branch line is X7;

[0056] Among them, X6 and X7 are basically equal.

[0057] According to an embodiment of the present disclosure, the sixth branch line has a first end and a second end; the first end of the sixth branch line is close to the first end of the main line, and the second end of the sixth branch line is close to the second end of the main line;

[0058] The orthographic projections of the second end of the sixth branch line and the second end of the main line on the second dielectric layer are both located outside the orthographic projection of the radiation patch on the second dielectric layer;

[0059] The distance between the orthographic projection of the second end of the sixth branch line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D9;

[0060] The distance between the orthographic projection of the second end of the main line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D5;

[0061] Among them, D9>D5.

[0062] According to another aspect of the present disclosure, an electronic device is provided, comprising the above-mentioned filtering antenna.

[0063] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0065] FIG1 is a schematic diagram of a stacked structure of a filtering antenna in one embodiment of the present disclosure.

[0066] FIG2 is a schematic diagram of a top view of the coupling probe in the first embodiment of the present disclosure.

[0067] FIG3 is a diagram showing frequency-gain simulation results of the filtering antenna of the first verification example of the present disclosure.

[0068] FIG4-1 is a surface current distribution diagram of the radiation patch at the low-frequency radiation zero point in the first verification example of the present disclosure.

[0069] FIG4-2 is a surface current distribution diagram of the radiation patch at the high-frequency radiation zero point in the first verification example of the present disclosure.

[0070] FIG5-1 is a surface current distribution diagram of the coupling probe at the low-frequency radiation zero point in the first verification example of the present disclosure.

[0071] FIG5-2 is a surface current distribution diagram of the coupling probe at the high-frequency radiation zero point in the first verification example of the present disclosure.

[0072] FIG6 is a schematic diagram of a top view of the coupling probe in the second embodiment of the present disclosure.

[0073] FIG7 is a diagram showing frequency-gain simulation results of the filtering antenna of the second verification example of the present disclosure.

[0074] FIG8-1 is a surface current distribution diagram of the radiation patch at the low-frequency radiation zero point in the second verification example of the present disclosure.

[0075] FIG8-2 is a surface current distribution diagram of the radiation patch at the high-frequency radiation zero point in the second verification example of the present disclosure.

[0076] FIG9-1 is a surface current distribution diagram of the coupling probe at the low-frequency radiation zero point in the second verification example of the present disclosure.

[0077] FIG9-2 is a surface current distribution diagram of the coupling probe at the high-frequency radiation zero point in the second verification example of the present disclosure.

[0078] FIG10 is a schematic diagram of a top view of the coupling probe in the third embodiment of the present disclosure.

[0079] FIG11 is a diagram showing frequency-gain simulation results of the filtering antenna of the third verification example of the present disclosure.

[0080] FIG12-1 is a surface current distribution diagram of the radiation patch at the low-frequency radiation zero point in the third verification example of the present disclosure.

[0081] FIG12-2 is a surface current distribution diagram of the radiation patch at the high-frequency radiation zero point in the third verification example of the present disclosure.

[0082] FIG13-1 is a surface current distribution diagram of the coupling probe at the low-frequency radiation zero point in the third verification example of the present disclosure.

[0083] FIG13-2 is a surface current distribution diagram of the coupling probe at the high-frequency radiation zero point in the third verification example of the present disclosure.

[0084] FIG14 is a schematic diagram of a top view of the structure of a coupling probe in the fourth embodiment of the present disclosure.

[0085] FIG15 is a diagram showing the frequency-gain simulation results of the filtering antenna of the fourth verification example of the present disclosure.

[0086] FIG16-1 is a surface current distribution diagram of the radiation patch at the low-frequency radiation zero point in the fourth verification example of the present disclosure.

[0087] FIG16-2 is a surface current distribution diagram of the radiation patch at the high-frequency radiation zero point in the fourth verification example of the present disclosure.

[0088] FIG17-1 is a surface current distribution diagram of the coupling probe at the low-frequency radiation zero point in the fourth verification example of the present disclosure.

[0089] FIG17-2 is a surface current distribution diagram of the coupling probe at the high-frequency radiation zero point in the fourth verification example of the present disclosure.

[0090] FIG18 is a schematic diagram of a top view of the structure of a coupling probe in the fifth embodiment of the present disclosure.

[0091] FIG19 is a diagram showing the frequency-gain simulation results of the filtering antenna of the fifth verification example of the present disclosure.

[0092] FIG20-1 is a surface current distribution diagram of the radiation patch at the low-frequency radiation zero point in the fifth verification example of the present disclosure.

[0093] FIG20-2 is a surface current distribution diagram of the radiation patch at the high-frequency radiation zero point in the fifth verification example of the present disclosure.

[0094] FIG21-1 is a surface current distribution diagram of the coupling probe at the low-frequency radiation zero point in the fifth verification example of the present disclosure.

[0095] FIG21-2 is a surface current distribution diagram of the coupling probe at the high-frequency radiation zero point in the fifth verification example of the present disclosure.

[0096] FIG22 is a schematic diagram of a top view of the structure of a coupling probe in the sixth embodiment of the present disclosure.

[0097] FIG23 is a diagram showing the frequency-gain simulation results of the filtering antenna of the sixth verification example of the present disclosure.

[0098] FIG24-1 is a surface current distribution diagram of the radiation patch at the low-frequency radiation zero point in the sixth verification example of the present disclosure.

[0099] FIG24-2 is a surface current distribution diagram of the radiation patch at the high-frequency radiation zero point in the sixth verification example of the present disclosure.

[0100] FIG25-1 is a surface current distribution diagram of the coupling probe at the low-frequency radiation zero point in the sixth verification example of the present disclosure.

[0101] FIG25-2 is a surface current distribution diagram of the coupling probe at the high-frequency radiation zero point in the sixth verification example of the present disclosure.

[0102] FIG26 is a schematic structural diagram of an electronic device in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0103] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many 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 and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0104] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.

[0105] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0106] An embodiment of the present disclosure provides a filtering antenna, see Figure 1, the filtering antenna includes a ground layer GNDL, a first dielectric layer ILDA, a second dielectric layer ILDB and a radiation patch RP stacked in sequence, and a coupling probe PRB. The coupling probe PRB includes a microstrip line PRB1 sandwiched between the first dielectric layer ILDA and the second dielectric layer ILDB, and a feeding element PRB2 that passes through the first dielectric layer ILDA. Referring to Figures 2, 6, 10, 14, 18 and 22, the microstrip line PRB1 includes a main line PA extending along a first direction X and an open branch line connected to the main line PA. The microstrip line PRB1 and the feeding element PRB2 of the present disclosure form an L probe, which transfers energy to the radiation patch RP of the antenna by proximity coupling.

[0107] Therefore, the filtering antenna provided in the embodiments of the present disclosure is a coupled probe-fed patch antenna with a low profile. This filtering antenna utilizes backfeed, resulting in a compact structure. Furthermore, this filtering antenna, as a patch antenna, offers advantages such as simple structure, ease of fabrication, and low cost.

[0108] From a circuit perspective, the radiating patch RP itself is equivalent to a first inductor and a first capacitor; the coupling probe PRB introduces an additional second inductor, while the coupling between the microstrip line PRB1 and the radiating patch RP creates an additional second capacitor. The first inductor and capacitor create a transmission pole, causing the filter antenna to resonate; the second inductor and capacitor create a transmission zero, which, in turn, creates a radiation null in the antenna structure.

[0109] Referring to Figures 2, 6, 10, 14, 18 and 22, the distance between the feeding center of the microstrip line PRB1 and the first end of the main line PA is D1; ​​the distance between the orthographic projection of the first end of the main line PA on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiation patch on the second dielectric layer ILDB is D4.

[0110] Wherein, 2.5≤D1 / D4≤3.0. In this way, the antenna can achieve better impedance matching.

[0111] In the embodiment of the present disclosure, the extension direction of the main line PA is the first direction X, and the direction perpendicular to the main line PA and parallel to the plane of the ground layer GNDL can be defined as the second direction Y. In this way, the first direction X, the second direction Y, and the normal direction of the filter antenna are mutually perpendicular.

[0112] In the embodiment of the present disclosure, the feeding center is not set at the center or end of the main line PA, but is set close to the first end of the main line PA and has a certain distance from the first end of the main line PA. This is conducive to introducing new resonant modes or impedance matching, thereby optimizing the performance of the filtering antenna and improving the compactness of the filtering antenna. Not only that, the main line PA can also introduce a high-frequency radiation zero point on the right side of the passband. The high-frequency radiation zero point of the filtering antenna is affected by the distance D4 in the first direction X between the first end of the main line PA and the edge RPE of the radiation patch and the length of the main line PA. In the embodiment of the present disclosure, 2.5≤D1 / D4≤3.0; on the one hand, this can better achieve impedance matching, and on the other hand, it is also conducive to adjusting and optimizing the filtering performance of the filtering antenna.

[0113] In the embodiment of the present disclosure, the introduction of the open branch line can introduce a low-frequency radiation zero point on the left side of the passband. In one example, the open branch line can include a section of open transmission line, and the total length of the open transmission line is approximately one-quarter of the propagation wavelength corresponding to the low-frequency radiation zero point. For example, the first branch line PB and the second branch line PC in Figure 2 can be used as a section of a bent open transmission line. Of course, it can be understood that the open branch line can also include other open structures to adjust parameters such as impedance, low-frequency radiation zero point, gain in the passband, passband flatness, and sideband selectivity.

[0114] Moreover, in the embodiment of the present disclosure, both the position of the feed center and the shape of the microstrip line PRB1 will adjust the resonant mode or introduce a new resonant mode in the filtering antenna, thereby making the filtering antenna have a wide bandwidth and good impedance matching.

[0115] The filter antenna provided in the embodiments of the present disclosure features a simple structural design and is therefore easy to manufacture. For example, conventional PCB processing techniques can be used to fabricate the filter antenna. The filter antenna can perform both antenna and filtering functions, and therefore, when used in antenna arrays, can reduce cross-frequency coupling between closely spaced antenna elements in different frequency bands.

[0116] In some embodiments of the present disclosure, the feed element PRB2 may be a metalized via penetrating the first dielectric layer ILDA. In other embodiments, the feed element PRB2 may be an inner conductor of a coaxial probe penetrating the first dielectric layer ILDA. Of course, the feed element PRB2 may also adopt other conductive structures and forms.

[0117] The structure, principle and effect of the filtering antenna according to the embodiment of the present disclosure are further explained and illustrated below with reference to the accompanying drawings.

[0118] Figure 2 illustrates a schematic diagram of the top structure of the coupling probe PRB in the first embodiment of the present disclosure. Figure 6 illustrates a schematic diagram of the top structure of the coupling probe PRB in the second embodiment of the present disclosure. Figure 10 illustrates a schematic diagram of the top structure of the coupling probe PRB in the third embodiment of the present disclosure. Figure 14 illustrates a schematic diagram of the top structure of the coupling probe PRB in the fourth embodiment of the present disclosure. Figure 18 illustrates a schematic diagram of the top structure of the coupling probe PRB in the fifth embodiment of the present disclosure. Figure 22 illustrates a schematic diagram of the top structure of the coupling probe PRB in the sixth embodiment of the present disclosure. It can be understood that the coupling probe PRB in the filtering antenna of the embodiment of the present disclosure is not limited to the six forms exemplified in Figures 2, 6, 10, 14, 18 and 22.

[0119] In one embodiment of the present disclosure, the distance between the feed center and the first end of the main line PA is D1, and the length of the main line PA is L1, wherein 0.15≤D1 / L1≤0.2.

[0120] 2 , 6 , 10 , 14 , 18 , and 22 , in some embodiments of the present disclosure, the width W1 of the main line PA is greater than the width of the open branch line, so that the antenna can achieve better impedance matching.

[0121] Referring to Figures 2, 6, 10, 14, 18 and 22, in some embodiments of the present disclosure, the main line PA has a first axis of symmetry along the first direction X; the radiation patch RP has a second axis of symmetry along the first direction X; the orthographic projection of the first axis of symmetry on the radiation patch RP coincides with the second axis of symmetry.

[0122] 2 , 6 , 10 , 14 , 18 and 22 , in some embodiments of the present disclosure, the orthographic projection of the first end of the main line PA on the second dielectric layer ILDB is within the orthographic projection range of the radiation patch RP on the second dielectric layer ILDB.

[0123] 2 , 6 , 10 , 14 , 18 and 22 , in some embodiments of the present disclosure, the orthographic projection of the first end of the first branch line PB on the second dielectric layer ILDB is outside the orthographic projection range of the radiation patch RP on the second dielectric layer ILDB.

[0124] Referring to Figures 2, 6, 10, 14, 18, and 22, in some embodiments of the present disclosure, the distance between the orthographic projection of the first end of the main line PA on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiating patch on the second dielectric layer ILDB is D4. The distance between the orthographic projection of the second end of the main line PA on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiating patch on the second dielectric layer ILDB is D5. D4 < D5. Furthermore, 0.45 ≤ D4 / D5 ≤ 0.6.

[0125] Thus, along the first direction X, the length of the main line PA is greater than the length of the radiating patch RP. The first end of the main line PA is within the coverage area of ​​the radiating patch RP, while the second end of the main line PA is outside the coverage area of ​​the radiating patch RP. By configuring D4 and D5, the filtering antenna can have a suitable high-frequency radiation null point.

[0126] Referring to Figures 2, 6, 10, 14, 18, and 22, in some embodiments of the present disclosure, the radius of the feed element PRB2 is between 0.35 and 0.45 mm. In one example, the inner conductor INC of a coaxial probe serves as the feed element PRB2, and the radius of the inner conductor INC of the coaxial probe is 0.4 mm. This allows for better impedance matching of the antenna.

[0127] In some embodiments of the present disclosure, the radius of the outer conductor of the coaxial probe CC may be between 0.6 and 1.2 mm. For example, the radius of the outer conductor may be 0.92 mm.

[0128] Referring to Figures 2, 6, 10, 14, 18, and 22, in some embodiments of the present disclosure, the radiating patch RP is square with a side length between 13 and 17 mm. This allows the filter antenna to operate at a central frequency of approximately 3.5 GHz. Furthermore, the radiating patch RP is square with a side length of 15 mm.

[0129] In some embodiments of the present disclosure, the ground layer GNDL is square with a side length between 35 and 45 mm. For example, the side length of the ground layer GNDL is 40 mm. The dimensions of the first dielectric layer ILDA and the second dielectric layer ILDB may be no smaller than the dimensions of the ground layer GNDL. For example, the edges of the first dielectric layer ILDA and the second dielectric layer ILDB may be flush with the ground layer GNDL or extend beyond the edges of the ground layer GNDL by 1 to 2 mm.

[0130] In one example, the central axis of the ground layer GNDL coincides with the central axis of the radiation patch RP.

[0131] 2 , 6 , 10 , 14 , 18 , and 22 , in some embodiments of the present disclosure, the length of the main line PA is 15 to 17 mm. For example, the length of the main line PA is 16 mm.

[0132] In some embodiments of the present disclosure, the ground layer GNDL, the radiation patch RP, and the microstrip line PRB1 are made of metal materials with excellent electrical conductivity, such as copper, gold, aluminum, and the like.

[0133] In some embodiments of the present disclosure, the thickness of any of the ground layer GNDL, the radiating patch RP, and the microstrip line PRB1 can be relatively thin, for example, no more than 50 microns, and particularly no more than 20 microns. In one example, the thickness of the ground layer GNDL, the radiating patch RP, and the microstrip line PRB1 are all 17 microns.

[0134] In some embodiments of the present disclosure, the second dielectric layer ILDB and the first dielectric layer ILDA may be made of the same material. Of course, the second dielectric layer ILDB and the first dielectric layer ILDA may also be made of different materials.

[0135] In some embodiments of the present disclosure, the thickness of the first dielectric layer ILDA is greater than the thickness of the second dielectric layer ILDB, and the thicknesses of the first dielectric layer ILDA and the second dielectric layer ILDB are both between 1 and 4 mm. For example, the thickness of the second dielectric layer ILDB is between 1 and 2 mm, and the thickness of the first dielectric layer ILDA is between 3 and 4 mm. It will be appreciated that the thicknesses of the first and second dielectric layers ILDA and ILDB may vary as the material properties of the first and second dielectric layers ILDA and ILDB change.

[0136] In some embodiments of the present disclosure, the dielectric constant of either the first dielectric layer ILDA or the second dielectric layer ILDB is between 5 and 7, thereby facilitating a reduction in thickness of the first dielectric layer ILDA and the second dielectric layer ILDB. For example, the dielectric constants of the first dielectric layer ILDA and the second dielectric layer ILDB are both 6.15.

[0137] In some embodiments of the present disclosure, the dielectric loss tangent of either the first dielectric layer ILDA or the second dielectric layer ILDB is no greater than 0.003 to reduce energy loss. For example, the dielectric loss tangent of either the first dielectric layer ILDA or the second dielectric layer ILDB is 0.002.

[0138] In one example, the dielectric constants of the first dielectric layer ILDA and the second dielectric layer ILDB are both 6.15, the dielectric loss tangents are both 0.002, the thickness of the first dielectric layer ILDA is 3.18 mm, and the thickness of the second dielectric layer ILDB is 1.27 mm.

[0139] In one embodiment of the present disclosure, the center operating frequency of the filtering antenna is 3.5 GHz. In one example, the filtering antenna operates in the 5G n78 frequency band.

[0140] As follows, the filtering antenna according to the embodiment of the present disclosure is further explained and illustrated by taking six embodiments, including the first to sixth embodiments, as examples.

[0141] First embodiment

[0142] FIG2 illustrates a schematic diagram of the top structure of the coupling probe PRB in the first embodiment of the present disclosure. Referring to FIG2 , the open branch line includes a first branch line PB and a second branch line PC; the first branch line PB is arranged in parallel with the main line PA, and the extension direction of the second branch line PC is perpendicular to the main line PA, that is, the second branch line PC extends along the second direction Y. The first end of the second branch line PC is connected to the main line PA, and the second end of the second branch line PC is connected to the first end of the first branch line PB, and the second end of the first branch line PB is located on the side of the second branch line PC close to the first end of the main line PA. In this embodiment, the first branch line PB and the second branch line PC together act as an open transmission line, which can cooperate with the main line PA to introduce a low-frequency radiation zero point in the passband of the filtering antenna. It can be understood that the low-frequency radiation zero point can be adjusted by adjusting the total length of the first branch line PB and the second branch line PC.

[0143] In the embodiment of the present disclosure, the length of the main line PA is L1, the length of the first branch line PB is L2, and the length of the second branch line PC is L3. The second branch line PC has a first side of the second branch line PC and a second side of the second branch line PC that are arranged opposite to each other. In the first direction X, the first side of the second branch line PC is located on the side of the second side of the second branch line PC close to the feeding center. The first branch line PB is located on the side of the first side of the second branch line PC away from the second side of the second branch line PC. Therefore, the length of the first branch line PB refers to the distance between the second end of the first branch line PB and the straight line where the first side of the second branch line PC is located.

[0144] In one example, 2.0≤L1 / L2≤2.4.

[0145] Optionally, the value of L2+L3 is within the range of 9.5 to 11.5 mm, for example, 10.5 mm. Thus, the low-frequency radiation null is approximately at 2.97 GHz. In one example, L3 is between 2.5 and 3.5 mm, and L2 is between 7 and 8 mm. For example, L2 is 7.5 mm and L3 is 3 mm.

[0146] In the disclosed embodiment, the distance between the feed center and the straight line on which the first side of the second branch line PC lies is D3, and the distance between the second end of the main line PA and the straight line on which the first side of the second branch line PC lies is X1. Optionally, D3 and X1 are substantially equal, for example, 0.9 ≤ D3 / X1 ≤ 1.1, and in particular, D3 / X1 = 1.

[0147] Optionally, in the first direction X, the second end of the first branch line PB is located between the feeding center and the first end of the main line PA.

[0148] In the embodiment of the present disclosure, the distance between the feeding center and the second end of the first branch wire PB is D2 in the first direction X. In one example, 0.3≤D2 / D1≤0.4, for example, D2 / D1=0.33.

[0149] Optionally, D2<D3, in particular 0.1≤D2 / D3≤0.2.

[0150] In the embodiment of the present disclosure, the distance between the main line PA and the first branch line PB is X2. Optionally, X2<D1, in particular, 0.5≤X2 / D1≤0.75.

[0151] In the disclosed embodiment, the width of the main line PA is W1. The width of the first branch line PB is W2. The width of the second branch line PC is W3. Optionally, W1 is between 1.2 and 2.0 mm; W2 is between 0.8 and 1.2 mm; and W3 is between 0.8 and 1.2 mm. W2 and W3 are both smaller than W1. Furthermore, W2 and W3 are equal.

[0152] In the disclosed embodiments, for ease of description, the portion of the main line PA between its first end and the second branch line PC is referred to as the first main line segment PAA, and the portion of the main line PA between its second end and the second branch line PC is referred to as the second main line segment PAB. In this embodiment, through these configurations, the filtering antenna introduces a new resonant mode to increase bandwidth and achieve better impedance matching. Furthermore, the filtering antenna incorporates filtering response characteristics, and has a compact structure and simple design.

[0153] This embodiment also provides a first verification example. In this first verification example, the side length of the ground layer GNDL is 40 mm; the dielectric constants of the first dielectric layer ILDA and the second dielectric layer ILDB are both 6.15; the dielectric loss tangents of the first dielectric layer ILDA and the second dielectric layer ILDB are both 0.002; the thickness of the first dielectric layer ILDA is 3.18 mm, and the thickness of the second dielectric layer ILDB is 1.27 mm; the side length of the radiation patch RP is 15 mm; and the thickness of the radiation patch RP, the ground layer GNDL, and the microstrip line PRB1 are all 17 microns. For other parameters of the filtering antenna of this first verification example, please refer to Table 1:

[0154] Table 1: Parameters of filter antenna

[0155] The present disclosure simulated the first verification example using HFSS software. For the simulation results, please see Figures 3, 4-1, 4-2, 5-1, and 5-2.

[0156] Figure 3 shows the frequency-gain simulation results for the filter antenna in this first verification example, plotting the simulated frequency (Freq) versus peak-realized gain (PeakRealizedGain) curve. As shown in Figure 3, there are radiation nulls on both sides of the passband, located at 2.985 GHz (low-frequency radiation null) and 4.085 GHz (high-frequency radiation null), respectively. Out-of-band suppression is greater than -20 dB, and gain flatness within the passband is excellent, exceeding 3.3 dBi from 3.37 to 3.70 GHz.

[0157] Figure 4-1 shows the surface current (Jsurf) distribution of the radiating patch at the low-frequency radiation zero point. As shown in Figure 4-1, at the low-frequency radiation zero point, the current intensity on the radiating patch is very weak, and the radiating patch basically does not participate in radiation.

[0158] Figure 4-2 shows the surface current (Jsurf) distribution of the radiating patch at the high-frequency radiation null point. As shown in Figure 4-2, at the high-frequency radiation null point, the current in the center of the radiating patch is weak and in opposite directions. The currents along the two radiating edges extending in the second direction Y (particularly the radiating edge near the second end of the main line PA) are higher, with the currents on either side of the radiating edges in opposite directions canceling each other out. This creates a high-frequency radiation null point for the filter antenna. In the subsequent surface current distribution diagrams, the primary current direction is indicated by a dashed arrow.

[0159] Figure 5-1 shows the surface current (Jsurf) distribution of the coupled probe PRB at the low-frequency radiation null. As shown in Figure 5-1, at this low-frequency radiation null, the current in the second segment of the main line (PAB) is very low. The currents in the first segment of the main line (PAA) and the first branch line (PB) flow in opposite directions, canceling each other out. Consequently, very little energy is coupled to the radiating patch, and the radiating patch contributes essentially no radiation. This creates a low-frequency radiation null in the filter antenna.

[0160] Figure 5-2 shows the surface current (Jsurf) distribution of the coupled probe PRB at the high-frequency radiation null. As shown in Figure 5-2, at the high-frequency radiation null, the currents on the first segment of the main line, PAA, and the first branch line, PB, have the same direction, and are strongest on the second segment of the main line, PAB. This indicates that a significant amount of energy on the microstrip line, PRB1, can be coupled to the radiating patch. However, the induced current on the radiating patch is in the opposite direction, forming a high-frequency radiation null.

[0161] Second embodiment

[0162] FIG6 illustrates a schematic diagram of a top view of the coupled probe PRB in the second embodiment of the present disclosure. Referring to FIG6 and FIG2 , the difference between the second embodiment and the first embodiment is that the open branch line further includes a third branch line PBx; the third branch line PBx extends in the same direction as the first branch line PB and is disposed on both sides of the second branch line PC. The first end of the third branch line PBx is connected to the second end of the second branch line PC; the orthographic projection of the second end of the third branch line PBx on the second dielectric layer ILDB is within the orthographic projection of the radiation patch RP on the second dielectric layer ILDB.

[0163] Compared with the first embodiment, the second embodiment can increase the length of the open stub line, which can reduce the low-frequency radiation zero point.

[0164] In the disclosed embodiment, the length of the third branch line PBx is L2x; the distance between the orthographic projection of the second end of the third branch line PBx on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiation patch on the second dielectric layer ILDB is X3. Optionally, X3 < L2x, in particular, 0.3 ≤ X3 / L2x ≤ 0.4.

[0165] This second embodiment also provides a second verification example, which differs from the first verification example only in that a third branch line PBx is added. The length L2x of the third branch line PBx is 2.5 mm, and the width of the third branch line PBx is the same as that of the first branch line PB, both being 1 mm.

[0166] The present disclosure simulated the second verification example using HFSS software. For the simulation results, please see Figures 7, 8-1, 8-2, 9-1, and 9-2.

[0167] Figure 7 shows the frequency-gain simulation results for the filter antenna in the second verification example, plotting the simulated frequency (Freq) versus peak-realized gain (PeakRealizedGain) curve. As shown in Figure 7, there are radiation nulls on both sides of the passband, located at 2.965 GHz (low-frequency radiation null) and 4.1 GHz (high-frequency radiation null), respectively. Out-of-band suppression is greater than -20 dB, and gain flatness within the passband is excellent, exceeding 3.3 dBi within the 3.38-3.71 GHz range.

[0168] Figure 8-1 shows the surface current (Jsurf) distribution of the radiating patch at the low-frequency radiation zero point. As shown in Figure 8-1, at the low-frequency radiation zero point, the current intensity on the radiating patch is very weak, and the radiating patch basically does not participate in radiation.

[0169] Figure 8-2 shows the surface current (Jsurf) distribution of the radiating patch at the high-frequency radiation null point. As shown in Figure 8-2, at the high-frequency radiation null point, the current intensity in the center of the radiating patch is relatively weak and in opposite directions. The current intensity on the two radiating edges extending along the second direction Y (particularly the radiating edge near the second end of the main line PA) is relatively strong. The currents on both sides of the radiating edges have opposite directions and cancel each other out. This creates a high-frequency radiation null point for the filter antenna.

[0170] Figure 9-1 shows the surface current (Jsurf) distribution of the coupled probe PRB at the low-frequency radiation null. As shown in Figure 9-1, at this low-frequency radiation null, the current in the second segment of the main line (PAB) is very low. The currents in the first segment of the main line (PAA) and the first branch line (PB) flow in opposite directions, canceling each other out. Consequently, very little energy is coupled to the radiating patch, and the radiating patch contributes essentially no radiation. This creates a low-frequency radiation null in the filter antenna.

[0171] Figure 9-2 shows the surface current (Jsurf) distribution of the coupled probe PRB at the high-frequency radiation null. As shown in Figure 9-2, at the high-frequency radiation null, the currents on the first segment of the main line, PAA, and the first branch line, PB, have the same direction, with the intensity being greatest on the second segment of the main line, PAB. This indicates that a significant amount of energy on the microstrip line, PRB1, can be coupled to the radiating patch. However, the induced current on the radiating patch is in the opposite direction, forming a high-frequency radiation null.

[0172] Third embodiment

[0173] Figure 10 illustrates a schematic diagram of the top structure of the coupling probe PRB in the third embodiment of the present disclosure. Referring to Figure 10 and Figure 2, the difference between the third embodiment and the first embodiment is that the open branch line also includes a fifth branch line PE and a fourth branch line PD. Wherein, the fourth branch line PD is arranged in parallel with the main line PA, and is located on both sides of the main line PA respectively with the first branch line PB. The fifth branch line PE is perpendicular to the main line PA; the first end of the fifth branch line PE is connected to the main line PA, and the second end of the fifth branch line PE is connected to the first end of the fourth branch line PD; the second end of the fourth branch line PD is located on the side of the first end of the fourth branch line PD close to the feeding center.

[0174] Compared with the first embodiment, the third embodiment can increase the length of the open branch line. The open branch line includes two parts located on both sides of the main line PA, one part including the fifth branch line PE and the fourth branch line PD, and the other part including the first branch line PB and the second branch line PC. On the one hand, by increasing the length of the open branch line, the radiation null point can be adjusted, especially the low-frequency radiation null point. On the other hand, the open branch lines are distributed on both sides of the main line PA, which can have a significant impact on the current path on the microstrip line PRB1, thereby significantly affecting the sideband selectivity and gain within the passband of the filtering antenna.

[0175] Optionally, the width W4 of the fourth branch line PD is the same as the width W2 of the first branch line PB, for example, both are 1 mm.

[0176] Optionally, referring to Figure 10 , the centerline of the fifth branch line PE and the centerline of the second branch line PC are located on the same straight line. Furthermore, the width W5 of the fifth branch line PE is the same as the width W3 of the second branch line PC, for example, both are 1 mm.

[0177] In the embodiment of the present disclosure, the spacing between the fourth branch line PD and the main line PA is X4; the spacing between the first branch line PB and the main line PA is X2. Optionally, X2 and X4 are substantially equal. For example, X2 and X4 are the same, such as both being 2 mm.

[0178] Optionally, the length of the first branch line PB is L2, and the length of the fourth branch line PD is L4. Optionally, L4 < L2, for example, 0.3 ≤ L4 / L2 ≤ 0.4; this can achieve a balance between impedance matching and radiation zero point matching. For example, L2 is 7.5 mm and L4 is 2.5 mm.

[0179] The third embodiment also provides a third verification example. This third verification example differs from the first verification example only in that a fourth branch line PD and a fifth branch line PE are added. The length L4 of the fourth branch line PD is 2.5 mm, the length L5 of the fifth branch line PE is 3 mm, the width W4 of the fourth branch line PD is 1 mm, and the width W5 of the fifth branch line PE is 1 mm.

[0180] The present disclosure simulated the third verification example using HFSS software. For the simulation results, please see Figures 11, 12-1, 12-2, 12-1, and 12-2.

[0181] Figure 11 is a frequency-gain simulation result diagram of the filtering antenna of the third verification example, showing the simulated frequency (Freq)-actual gain (PeakRealizedGain) curve. Referring to Figure 11, there is a radiation null on both sides of the passband, located at 2.975GHz (low-frequency radiation null) and 3.945GHz (high-frequency radiation null); the out-of-band suppression level is greater than -20dB. Compared with the second verification example, the gain flatness within the passband and the sideband selectivity of the third verification example are slightly deteriorated, but the gain within the passband is significantly improved, with the gain within 3.31-3.46GHz being greater than 5dBi.

[0182] Figure 12-1 shows the surface current (Jsurf) distribution of the radiating patch at the low-frequency radiation zero point. As shown in Figure 12-1, at the low-frequency radiation zero point, the current intensity on the radiating patch is very weak, and the radiating patch basically does not participate in radiation.

[0183] Figure 12-2 shows the surface current (Jsurf) distribution of the radiating patch at the high-frequency radiation null point. As shown in Figure 12-2, at the high-frequency radiation null point, the current intensity in the center of the radiating patch is relatively weak and in opposite directions. The current intensity on the two radiating edges extending along the second direction Y (particularly the radiating edge near the second end of the main line PA) is relatively high. The currents on both sides of the radiating edges have opposite directions and cancel each other out. This creates a high-frequency radiation null point for the filter antenna.

[0184] Figure 13-1 shows the surface current (Jsurf) distribution of the coupled probe PRB at the low-frequency radiation null. As shown in Figure 13-1, at the low-frequency radiation null, the currents in the first segment of the main line, PAA, and the first branch line, PB, have opposite directions, canceling each other out. The currents in the second segment of the main line, PAB, and the fourth branch line, PD, also have opposite directions, canceling each other out. Consequently, very little energy is coupled to the radiating patch, and the radiating patch contributes essentially no radiation. This creates a low-frequency radiation null in the filter antenna.

[0185] Figure 13-2 shows the surface current (Jsurf) distribution of the coupled probe PRB at the high-frequency radiation null. As shown in Figure 13-2, at the high-frequency radiation null, the currents on the first segment of the main line, PAA, and the first branch line, PB, have the same direction, with the current intensity being greatest on the second segment, PAB, of the main line. The currents on the fourth branch line, PD, and the first segment, PAA, of the main line have opposite directions, but the current intensity on the fourth branch line, PD, is less than that on the first segment, PAA. Therefore, a significant amount of energy on the microstrip line, PRB1, can be coupled to the radiating patch. However, the induced currents on the radiating patch are in the opposite direction, forming a high-frequency radiation null.

[0186] Fourth embodiment

[0187] Figure 14 illustrates a schematic diagram of the top structure of the coupling probe PRB in the fourth embodiment of the present disclosure. Referring to Figure 14 and Figure 2, the difference between the fourth embodiment and the first embodiment is that the open branch line also includes a fifth branch line PE and a fourth branch line PD. The fourth branch line PD is arranged in parallel with the main line PA, and is located on both sides of the main line PA with the first branch line PB; the fifth branch line PE is perpendicular to the main line PA; the first end of the fifth branch line PE is connected to the main line PA, and the second end of the fifth branch line PE is connected to the first end of the fourth branch line PD; the second end of the fourth branch line PD is located on the side of the first end of the fourth branch line PD away from the feeding center. Compared with the third embodiment, the fourth branch line PD and the first branch line PB of the fourth embodiment are located on both sides of the fifth branch line PE and the second branch line PC, respectively.

[0188] Compared with the first embodiment, this fourth embodiment can increase the length of the open branch line. The open branch line includes two parts located on both sides of the main line PA, one part including the fifth branch line PE and the fourth branch line PD, and the other part including the first branch line PB and the second branch line PC. On the one hand, by increasing the length of the open branch line, the radiation null point can be adjusted, especially the low-frequency radiation null point. On the other hand, the open branch lines are distributed on both sides of the main line PA, which can have a significant impact on the current path on the microstrip line PRB1, thereby significantly affecting the sideband selectivity and gain within the passband of the filtering antenna.

[0189] Optionally, the width W4 of the fourth branch line PD is the same as the width W2 of the first branch line PB, for example, both are 1 mm.

[0190] Optionally, referring to Figure 14 , the centerline of the fifth branch line PE and the centerline of the second branch line PC are located on the same straight line. Furthermore, the width W5 of the fifth branch line PE is the same as the width W3 of the second branch line PC, for example, both are 1 mm.

[0191] In the disclosed embodiment, the spacing between the fourth branch line PD and the main line PA is X4; the spacing between the first branch line PB and the main line PA is X2. Optionally, X2 and X4 are substantially equal, for example, 0.95 ≤ X2 / X4 ≤ 1.05. For example, X2 and X4 are the same, such as both 2 mm.

[0192] Optionally, the length of the first branch line PB is L2, and the length of the fourth branch line PD is L4. 0.3≤L2 / L4≤0.4; in this way, a balance between impedance matching and radiation zero point matching can be achieved. For example, L2 is 7.5 mm, and L4 is 2.5 mm.

[0193] Optionally, the orthographic projection of the second end of the fourth branch line PD on the second dielectric layer ILDB is located within the orthographic projection of the radiation patch RP on the second dielectric layer ILDB. The length of the fourth branch line PD is L4; the distance between the orthographic projection of the second end of the fourth branch line PD on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiation patch on the second dielectric layer ILDB is X5. Wherein, X5 < L4, for example, 0.3 ≤ X5 / L4 ≤ 0.4.

[0194] This fourth embodiment also provides a fourth verification example. This fourth verification example differs from the third verification example only in that the fourth branch line PD is located on the side of the fifth branch line PE that is away from the feed center. This disclosure simulated this fourth verification example using HFSS software. The simulation results are shown in Figures 15, 16-1, 16-2, 17-1, and 17-2.

[0195] Figure 15 is a frequency-gain simulation result diagram of the filter antenna of the fourth verification example, showing the simulated frequency (Freq)-actual gain (PeakRealizedGain) curve. Referring to Figure 15, there is a radiation null on both sides of the passband, located at 2.975GHz (low-frequency radiation null) and 3.965GHz (high-frequency radiation null); the out-of-band suppression level is greater than -20dB. Compared with the second verification example, the gain flatness within the passband and the sideband selectivity of the fourth verification example are slightly deteriorated, but the gain within the passband is significantly improved, and the gain within 3.30-3.48GHz is greater than 5dBi.

[0196] Figure 16-1 shows the surface current (Jsurf) distribution of the radiating patch at the low-frequency radiation zero point. As shown in Figure 16-1, at the low-frequency radiation zero point, the current intensity on the radiating patch is very weak, and the radiating patch basically does not participate in radiation.

[0197] Figure 16-2 shows the surface current (Jsurf) distribution of the radiating patch at the high-frequency radiation null point. As shown in Figure 16-2, at the high-frequency radiation null point, the current in the center of the radiating patch is weak and in opposite directions. The currents along the two radiating edges extending along the second direction Y (particularly the radiating edge near the second end of the main line PA) are stronger, with the currents on either side of the radiating edges in opposite directions, thus canceling each other out. This creates a high-frequency radiation null point in the filter antenna.

[0198] Figure 17-1 shows the surface current (Jsurf) distribution of the coupled probe PRB at the low-frequency radiation null. As shown in Figure 17-1, at the low-frequency radiation null, the currents in the first segment of the main line (PAA), the second segment of the main line (PAB), the first branch line (PB), and the fourth branch line (PD) are directed in opposite directions, canceling each other out. Consequently, very little energy is coupled to the radiating patch, and the radiating patch contributes essentially no radiation. This creates a low-frequency radiation null in the filter antenna.

[0199] Figure 17-2 shows the surface current (Jsurf) distribution of the coupled probe PRB at the high-frequency radiation null. As shown in Figure 17-2, at the high-frequency radiation null, the currents on the first segment PAA of the main line, the second segment PAB of the main line, the first branch line PB, and the fourth branch line PD all have the same direction, with the intensity being greatest on the second segment PAB of the main line. Therefore, a significant amount of energy on the microstrip line PRB1 can be coupled to the radiating patch. However, the induced current on the radiating patch is in the opposite direction, forming a high-frequency radiation null.

[0200] Compared to the third verification example, the length of the open-circuited branch line in this fourth verification example remains unchanged; the only difference is that the fourth branch line PD is positioned opposite the fifth branch line PE. This change in the orientation of the fourth branch line PD has minimal impact on the current path on the main line PA, and therefore has minimal impact on the filter antenna's sideband selectivity and gain within the passband.

[0201] Fifth embodiment

[0202] Figure 18 illustrates a top-down schematic diagram of the coupled probe PRB in the fifth embodiment of the present disclosure. Referring to Figure 18 and Figure 2 , this fifth embodiment differs from the first embodiment in that the microstrip line PRB1 further includes a proximity-coupling branch line. The proximity-coupling branch line includes a sixth branch line PF, which is arranged parallel to the main line PA and, along with the open branch line, is located on either side of the main line PA.

[0203] In an embodiment of the present disclosure, the sixth branch line PF has a first end of the sixth branch line PF close to the first end of the main line PA and a second end of the sixth branch line PF close to the second end of the main line PA. In the first direction X, the dimension between the first end of the sixth branch line PF and the feeding center is D6. Optionally, D6 < D1, in particular 0.5 ≤ D6 / D1 ≤ 0.75, for example D6 / D1 = 0.66. In this embodiment, in the first direction X, the first end of the sixth branch line PF is located between the feeding center and the first end of the main line PA.

[0204] In the disclosed embodiment, the spacing between the sixth branch line PF and the main line PA is D7. Optionally, D7 is not greater than the radius of the feeder PRB2. For example, the radius of the feeder PRB2 is 0.4 mm, and D7 is 0.3 mm. In this way, there is a small gap between the main line PA and the sixth branch line PF, which facilitates coupling between the main line PA and the sixth branch line PF.

[0205] In the embodiment of the present disclosure, the length of the sixth branch line PF is L6. Optionally, L6 < L1, in particular 0.9 ≤ L6 / L1 < 1.0. In this way, the second end of the main line PA and the second end of the sixth branch line PF can be close to each other. Of course, as needed, the length of the sixth branch line PF can be longer or shorter. In one example, the second end of the sixth branch line PF is flush with the second end of the main line PA.

[0206] Optionally, the second end of the sixth branch line PF is beyond the coverage of the radiation patch RP.

[0207] In the embodiment of the present disclosure, the width of the sixth branch line PF is W6. Optionally, 0.9≤W6 / W1≤1.1, for example, W6=W1.

[0208] This fifth embodiment also provides a fifth verification example, which differs from the first verification example only in the addition of a sixth branch line PF. The length L6 of the sixth branch line PF is 15 mm, and the width W6 of the sixth branch line PF is 1 mm. In the first direction X, the distance D6 between the first end of the sixth branch line PF and the feed center is 2 mm, and the second end of the sixth branch line PF is flush with the second end of the main line PA. The distance D7 between the sixth branch line PF and the main line PA is 0.3 mm.

[0209] The present disclosure simulated the fifth verification example using HFSS software. For the simulation results, please see Figures 19, 20-1, 20-2, 21-1, and 21-2.

[0210] Figure 19 shows the frequency-gain simulation results for the fifth verification example's filter antenna, plotting the simulated frequency (Freq) versus peak-realized gain (PeakRealizedGain) curve. Referring to Figure 18, there are radiation nulls on both sides of the passband, located at 2.97 GHz (low-frequency radiation null) and 4.075 GHz (high-frequency radiation null), respectively. Out-of-band suppression is greater than -20 dB. Gain flatness within the passband is excellent, exceeding 3.3 dBi from 3.33 to 3.71 GHz.

[0211] Figure 20-1 shows the surface current (Jsurf) distribution of the radiating patch at the low-frequency radiation zero point. As shown in Figure 20-1, at the low-frequency radiation zero point, the current intensity on the radiating patch is very weak, and the radiating patch basically does not participate in radiation.

[0212] Figure 20-2 shows the surface current (Jsurf) distribution of the radiating patch at the high-frequency radiation null point. As shown in Figure 20-2, at the high-frequency radiation null point, the current intensity in the center of the radiating patch is relatively weak and in opposite directions. The current intensity on the two radiating edges extending along the second direction Y (particularly the radiating edge near the second end of the main line PA) is relatively strong. The currents on both sides of the radiating edges have opposite directions and cancel each other out. This creates a high-frequency radiation null point for the filtering antenna.

[0213] Figure 21-1 shows the surface current (Jsurf) distribution of the coupled probe PRB at the low-frequency radiation null. As shown in Figure 21-1, at the low-frequency radiation null, the currents in the first segment PAA of the main line and the first branch line PB flow in opposite directions, canceling each other's energy. Furthermore, the currents in the two coupled edges of the sixth branch line PF, extending along the first direction X, flow in opposite directions, canceling each other's energy. Consequently, very little energy is coupled to the radiating patch, and the radiating patch contributes essentially to no radiation. This creates a low-frequency radiation null in the filtering antenna.

[0214] Figure 21-2 shows the surface current (Jsurf) distribution of the coupled probe PRB at the high-frequency radiation null point. As shown in Figure 21-2, at the high-frequency radiation null point, the currents on the first segment PAA of the main line and the first branch line PB have the same direction, and the intensity is greatest on the second segment PAB of the main line. The currents on the two coupled edges of the sixth branch line PF, extending along the first direction X, have opposite directions, and their energies cancel each other out. Therefore, a large amount of energy on the microstrip line PRB1 can be coupled to the radiating patch. However, the induced currents on the radiating patch are opposite, forming a high-frequency radiation null point.

[0215] Compared to the first verification example, the fifth verification example maintains the same length of the open-circuit stubs, but introduces additional proximity-coupled stubs. However, the currents in the proximity-coupled stubs are directed in opposite directions, minimizing the impact on the current path of the main PA and the filter antenna's sideband selectivity and passband gain.

[0216] Sixth embodiment

[0217] Figure 22 illustrates a schematic diagram of the top view structure of the coupling probe PRB in the sixth embodiment of the present disclosure. Referring to Figure 22 and Figure 18, the difference between the sixth embodiment and the fifth embodiment is that the adjacent coupling branch line also includes a seventh branch line PG. The seventh branch line PG is perpendicular to the sixth branch line PF; the first end of the seventh branch line PG is connected to the sixth branch line PF, and the orthographic projection of the second end of the seventh branch line PG on the second dielectric layer ILDB is located outside the orthographic projection of the radiation patch RP on the second dielectric layer ILDB. In other words, the seventh branch line PG extends along the second direction Y and is arranged on the side of the sixth branch line PF away from the main line PA. The second end of the seventh branch line PG extends into the coverage range of the radiation patch RP.

[0218] In the disclosed embodiment, the seventh branch line PG has a first side and a second side that are disposed opposite each other. In the first direction X, the first side of the seventh branch line PG is located on a side of the second side of the seventh branch line PG that is closer to the feed center. The distance between the feed center and the line containing the first side of the seventh branch line PG is D8. The length of the sixth branch line PF is L6x.

[0219] Optional, 0.3≤D8 / L6x≤0.4.

[0220] In the embodiment of the present disclosure, the sixth branch line PF has a first end of the sixth branch line PF close to the first end of the main line PA and a second end of the sixth branch line PF close to the second end of the main line PA; the distance between the first end of the sixth branch line PF and the first side of the seventh branch line PG is X6, and the distance between the second end of the sixth branch line PF and the second side of the seventh branch line PG is X7.

[0221] Optionally, X6 and X7 are substantially equal, for example, 0.95≤X6 / X7≤1.05.

[0222] In the disclosed embodiment, referring to FIG22 , the second end of the sixth branch line PF and the second end of the main line PA both extend beyond the coverage of the radiating patch RP. The distance between the orthographic projection of the second end of the sixth branch line PF on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiating patch on the second dielectric layer ILDB is D9. The distance between the orthographic projection of the second end of the main line PA on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiating patch on the second dielectric layer ILDB is D5.

[0223] Optionally, D9>D5, for example, 1.9≤D9 / D5≤2.0.

[0224] In the embodiment of the present disclosure, the distance between the orthographic projection of the second end of the seventh branch line PG on the second dielectric layer ILDB and the orthographic projection of the edge RPE of the radiation patch on the second dielectric layer ILDB is D10, and the length of the seventh branch line PG is L7. Optionally, 0.3≤D10 / L7≤0.4.

[0225] Optionally, the width W7 of the seventh branch line PG is greater than the width W6 of the sixth branch line PF.

[0226] In this embodiment, the introduced proximity-coupling spur lines include both a sixth spur line PF extending along the first direction X and a seventh spur line PG extending along the second direction Y. The ends of both the sixth and seventh spur lines PF and PG extend beyond the coverage area of ​​the radiating patch RP. Therefore, these proximity-coupling spur lines can significantly influence the current path on the main line PA, thereby adjusting the performance of the filtering antenna.

[0227] The sixth embodiment also provides a sixth verification example, which differs from the first verification example only in that a sixth branch line PF and a seventh branch line PG are added. The length L6x of the sixth branch line PF is 17 mm, and the width W6 of the sixth branch line PF is 1 mm; in the first direction X, the distance D6 between the first end of the sixth branch line PF and the feeding center is 2 mm. The distance D7 between the sixth branch line PF and the main line PA is 0.3 mm. The length L7 of the seventh branch line PG is 8 mm, and the width W7 of the seventh branch line PG is 1.2 mm. In the first direction X, the distance D8 between the first side of the seventh branch line PG and the feeding center is 5.9 mm.

[0228] The present disclosure simulated the sixth verification example using HFSS software. For the simulation results, please see Figures 23, 24-1, 24-2, 25-1, and 25-2.

[0229] Figure 23 shows the frequency-gain simulation results for the filter antenna of the sixth verification example, plotting the simulated frequency (Freq) versus peak-realized gain (PeakRealizedGain) curve. As shown in Figure 23, there are radiation nulls on both sides of the passband, located at 2.955 GHz (low-frequency radiation null) and 4.06 GHz (high-frequency radiation null), respectively; out-of-band suppression is greater than -20 dB. Compared to the first verification example, the gain flatness within the passband and the sideband selectivity of this sixth verification example are slightly worse, with a gain greater than 3.3 dBi within 3.20-3.52 GHz.

[0230] Figure 24-1 shows the surface current (Jsurf) distribution of the radiating patch at the low-frequency radiation zero point. As shown in Figure 24-1, at the low-frequency radiation zero point, the current intensity on the radiating patch is very weak, and the radiating patch basically does not participate in radiation.

[0231] Figure 24-2 shows the surface current (Jsurf) distribution of the radiating patch at the high-frequency radiation null point. As shown in Figure 24-2, at the high-frequency radiation null point, the current intensity in the center of the radiating patch is relatively weak and in opposite directions. The current intensity on the two radiating edges extending along the second direction Y (particularly the radiating edge near the second end of the main line PA) is relatively strong. The currents on both sides of the radiating edges have opposite directions and cancel each other out. This creates a high-frequency radiation null point for the filtering antenna.

[0232] Figure 25-1 shows the surface current (Jsurf) distribution of the coupled probe PRB at the low-frequency radiation null. As shown in Figure 25-1, at the low-frequency radiation null, the currents in the first segment of the main line (PAA) and the first branch line (PB) are directed in opposite directions, canceling each other's energy. The currents in adjacent coupled branches form a closed loop, canceling each other's energy. Consequently, very little energy is coupled to the radiating patch, and the radiating patch contributes essentially no radiation. This creates a low-frequency radiation null in this filtering antenna.

[0233] Figure 25-2 shows the surface current (Jsurf) distribution of the coupled probe PRB at the high-frequency radiation null. As shown in Figure 25-2, at the high-frequency radiation null, the currents on the first segment of the main line, PAA, and the first branch line, PB, have the same direction, with the currents being strongest on the second segment of the main line, PAB. The currents on adjacent coupled branch lines do not completely cancel each other out, but their intensities are relatively weak. Therefore, a significant amount of energy on the microstrip line PRB1 can be coupled to the radiating patch. However, the induced currents on the radiating patch are in the opposite direction, forming a high-frequency radiation null.

[0234] The present disclosure also provides an electronic device, see Figure 26, which can have any one of the filtering antennas 100 described in the above filtering antenna embodiments. In some examples, the electronic device is a 5G terminal, such as a tablet computer, a notebook, etc. In other examples, the electronic device can also be a device with a tag antenna, and at least one tag antenna in the device adopts the filtering antenna described in the above filtering antenna embodiments. In this way, the electronic device can achieve active or passive identification or reading. In other embodiments, the electronic device is a wearable device, such as wearable clothes, hats, glasses, gloves, etc., so that the wearable device can achieve body area network communication through the filtering antenna. Furthermore, the filtering antenna can be set on a biocompatible material or a fabric material, or part of the material of the filtering antenna can be made of a biocompatible material or a fabric material.

[0235] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A filtering antenna, comprising a ground layer, a first dielectric layer, a second dielectric layer and a radiation patch which are stacked in sequence, and a coupling probe; the coupling probe comprises a microstrip line sandwiched between the first dielectric layer and the second dielectric layer, and a feeding element penetrating the first dielectric layer; the microstrip line comprises a main line extending in a first direction and an open branch line connected to the main line; the feeding element is electrically connected to the main line; the distance between the feeding center of the microstrip line and the first end of the main line is D1; ​​the distance between the orthographic projection of the first end of the main line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D4; in, 2.5≤D1 / D4≤3.

0.

2. The filtering antenna according to claim 1, wherein: The width of the main line is greater than the width of the open branch line.

3. The filtering antenna according to claim 1, wherein: The main line has a first symmetry axis along the first direction; the radiation patch has a second symmetry axis along the first direction; The orthographic projection of the first symmetry axis on the radiation patch coincides with the second symmetry axis.

4. The filtering antenna according to claim 1, wherein: The orthographic projection of the first end of the main line on the second dielectric layer is located within the orthographic projection range of the radiation patch on the second dielectric layer.

5. The filtering antenna according to claim 1, wherein: The distance between the orthographic projection of the second end of the trunk line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D5; Among them, D4<D5.

6. The filtering antenna according to claim 1, wherein: The radius of the feeding element is between 0.35 and 0.45 mm.

7. The filtering antenna according to claim 1, wherein: The radiation patch is square, and the side length is between 13 and 17 mm.

8. The filtering antenna according to claim 1, wherein: The length of the main line is between 15 and 17 mm.

9. The filtering antenna according to any one of claims 1 to 8, wherein: The open branch line includes a first branch line extending along the first direction and a second branch line extending along the second direction; the second direction is perpendicular to the first direction; a first end of the second branch line is connected to the main line, and a second end of the second branch line is connected to a first end of the first branch line, and the second end of the first branch line is located on a side of the second branch line close to the first end of the main line; The length of the main line is L1, and the length of the first branch line is L2; Among them, 2.0≤L1 / L2≤2.

4.

10. The filtering antenna according to claim 9, wherein: The second branch line has a first side of the second branch line and a second side of the second branch line that are arranged opposite to each other; in the first direction, the first side of the second branch line is located on a side of the second side of the second branch line close to the feeding center; the distance between the feeding center and the straight line where the first side of the second branch line is located is D3, and the distance between the second end of the main line and the straight line where the first side of the second branch line is located is X1; Among them, D3 is basically equal to X1.

11. The filtering antenna according to claim 9, wherein: In the first direction, the second end of the first branch line is located between the feeding center and the first end of the trunk line.

12. The filtering antenna according to claim 11, wherein: In the first direction, the distance between the feeding center and the second end of the first branch line is D2; Among them, D2<D3.

13. The filtering antenna according to claim 9, wherein: The distance between the main line and the first branch line is X2; Among them, X2 is smaller than D1.

14. The filtering antenna according to claim 9, wherein: The open branch line also includes a third branch line; the third branch line has the same extension direction as the first branch line and is respectively arranged on both sides of the second branch line; the first end of the third branch line is connected to the second end of the second branch line; the orthographic projection of the second end of the third branch line on the second dielectric layer is located within the orthographic projection of the radiation patch on the second dielectric layer.

15. The filtering antenna according to claim 14, wherein: The length of the third branch line is L2x; the distance between the orthographic projection of the second end of the third branch line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is X3; Among them, X3<L2x.

16. The filtering antenna according to claim 9, wherein: The open branch line further includes a fifth branch line extending along the second direction and a fourth branch line extending along the first direction; The fourth branch line and the first branch line are respectively located on both sides of the main line; the first end of the fifth branch line is connected to the main line, and the second end of the fifth branch line is connected to the first end of the fourth branch line; the second end of the fourth branch line is located on the side of the first end of the fourth branch line close to the feeding center.

17. The filtering antenna according to claim 16, wherein: The center line of the fifth branch line and the center line of the second branch line are located on the same straight line.

18. The filtering antenna according to claim 16, wherein: The distance between the fourth branch line and the main line is X4; the distance between the first branch line and the main line is X2; Among them, X2 and X4 are basically equal.

19. The filtering antenna according to claim 16, wherein: The length of the first branch line is L2, and the length of the fourth branch line is L4; Among them, L4<L2.

20. The filtering antenna according to claim 9, wherein: The open branch line also includes a fifth branch line extending along the second direction and a fourth branch line extending along the first direction, the fourth branch line and the first branch line are respectively located on both sides of the main line; the first end of the fifth branch line is connected to the main line, and the second end of the fifth branch line is connected to the first end of the fourth branch line; the second end of the fourth branch line is located on the side of the first end of the fourth branch line away from the feeding center.

21. The filtering antenna according to claim 20, wherein: The center line of the fifth branch line and the center line of the second branch line are located on the same straight line.

22. The filtering antenna according to claim 20, wherein: The distance between the fourth branch line and the main line is X4; the distance between the first branch line and the main line is X2; Among them, X2 and X4 are basically equal.

23. The filtering antenna according to claim 20, wherein: The orthographic projection of the second end of the fourth branch line on the second dielectric layer is located within the orthographic projection of the radiation patch on the second dielectric layer; the length of the fourth branch line is L4; The distance between the orthographic projection of the second end of the fourth branch line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is X5; Among them, X5<L4.

24. The filtering antenna according to claim 9, wherein: The microstrip line further includes a sixth branch line extending along the first direction, and the sixth branch line and the open branch line are respectively located on two sides of the main line.

25. The filtering antenna according to claim 24, wherein: The sixth branch line has a first end and a second end; the first end of the sixth branch line is close to the first end of the main line, and the second end of the sixth branch line is close to the second end of the main line; In the first direction, the distance between the first end of the sixth branch line and the feeding center is D6; Among them, D6<D1.

26. The filtering antenna according to claim 24, wherein: The distance between the sixth branch line and the main line is D7; The D7 is not greater than the radius of the feeding element.

27. The filtering antenna according to claim 24, wherein: The length of the sixth branch line is L6; the length of the main line is L1; Among them, L6<L1.

28. The filtering antenna according to claim 24, wherein: The microstrip line also includes a seventh branch line extending along the second direction; the first end of the seventh branch line is connected to the sixth branch line, and the orthographic projection of the second end of the seventh branch line on the second dielectric layer is located outside the orthographic projection of the radiation patch on the second dielectric layer.

29. The filtering antenna according to claim 28, wherein: The seventh branch line has a first side and a second side that are arranged opposite to each other; in the first direction, the first side of the seventh branch line is located on a side of the second side close to the feeding center; The sixth branch line has a first end and a second end; the first end of the sixth branch line is close to the first end of the main line, and the second end of the sixth branch line is close to the second end of the main line; the distance between the first end of the sixth branch line and the first side of the seventh branch line is X6, and the distance between the second end of the sixth branch line and the first side of the seventh branch line is X7; Among them, X6 and X7 are basically equal.

30. The filtering antenna according to claim 28, wherein: The sixth branch line has a first end and a second end; the first end of the sixth branch line is close to the first end of the main line, and the second end of the sixth branch line is close to the second end of the main line; The orthographic projections of the second end of the sixth branch line and the second end of the main line on the second dielectric layer are both located outside the orthographic projection of the radiation patch on the second dielectric layer; The distance between the orthographic projection of the second end of the sixth branch line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D9; The distance between the orthographic projection of the second end of the trunk line on the second dielectric layer and the orthographic projection of the edge of the radiation patch on the second dielectric layer is D5; Among them, D9>D5.

31. An electronic device comprising the filtering antenna according to any one of claims 1 to 30.

Images