A multi-element electrically small antenna with reconfigurable side-firing and horizontal omnidirectional patterns

Abstract

The present application provides a multi-element electric small antenna with reconfigurable side-firing and horizontal omnidirectional patterns, including a first dielectric substrate and a second dielectric substrate arranged in parallel with each other; the first dielectric substrate is provided with a first radiating metal patch and a T-shaped connecting metal patch on the upper and lower surfaces respectively, and the second dielectric substrate is provided with a second radiating metal patch and a T-shaped radiating patch on the lower surface; the first radiating metal patch, the T-shaped connecting metal patch, and the second radiating metal patch are connected to each other through metal columns; PIN diodes are loaded on the first radiating metal patch, the second radiating metal patch, and between the second radiating metal patch and the T-shaped radiating patch, and the far-field directional pattern switching between side-firing and horizontal omnidirectional radiation is realized by switching the on-off state of the three PIN diodes. The present invention breaks through the previous directional pattern beam reconfiguration and antenna polarization mode reconfiguration, and realizes the reconfiguration of two types of directional patterns: vertically polarized horizontal omnidirectional radiation and circularly polarized side-firing.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, in particular to a multi-dipole electric small antenna with reconfigurable side-firing and horizontal omnidirectional directional patterns. Background Art

[0002] With the rapid development of wireless communication systems, reconfigurable antennas have received more and more attention due to their ability to improve the communication capacity of wireless systems, eliminate polarization mismatches, and expand the coverage of antenna radiation. Reconfigurable antennas are mainly divided into frequency, polarization, and pattern reconfigurable antennas. Among them, pattern reconfigurable antennas can dynamically change the antenna radiation direction and antenna radiation beam type, effectively reduce noise interference and expand signal coverage, and have therefore been widely studied. Electrically small antennas are suitable for compact environments because of their small size. The design of electrically small antennas is mainly a combination of dipole / monopole arrays, corresponding to high-gain antennas such as Huygens and Yagi, broadband antennas, and so on. However, there are relatively few reports on electrically small antennas with reconfigurable patterns. Summary of the invention

[0003] The purpose of the present invention is to provide a multi-dipole electric small antenna with reconfigurable side-firing and horizontal omnidirectional directional patterns.

[0004] The object of the present invention is achieved through such a technical solution, which comprises a first dielectric substrate and a second dielectric substrate arranged parallel to each other;

[0005] A first radiating metal patch is disposed on the upper surface of the first dielectric substrate, a T-shaped connecting metal patch is disposed on the lower surface of the first dielectric substrate, and a second radiating metal patch and a T-shaped radiating patch are disposed on the lower surface of the second dielectric substrate;

[0006] The first radiating metal patch and the T-shaped connecting metal patch, the first radiating metal patch and the second radiating metal patch, and the T-shaped connecting metal patch and the second radiating metal patch are all connected via metal columns;

[0007] The first radiating metal patch is loaded with a first PIN diode, the second radiating metal patch is loaded with a second PIN diode, the second radiating metal patch is connected to the T-shaped radiating patch via a third PIN diode, and the far-field radiation pattern switching between side-radiating and horizontal omnidirectional radiation is achieved by switching the on-off states of the first PIN diode, the second PIN diode, and the third PIN diode.

[0008] Further, the first radiation metal patch includes a first rectangular strip and a second rectangular strip that are orthogonally arranged to each other, both ends of the first rectangular strip are connected to a first fan ring strip, and both ends of the second rectangular strip are connected to a second fan ring strip;

[0009] The first radiating metal patch is also provided with a rectangular annular groove and two centrally symmetrical circular holes. The two ends of the first PIN diode are respectively connected to the patches on both sides of the rectangular annular groove. The first radiating metal patch is connected to the second radiating metal patch through three first metal pillars. The first radiating metal patch is connected to the T-shaped connecting metal patch through a second metal pillar.

[0010] Further, the T-shaped connecting metal sheet includes a sixth rectangular strip and a seventh rectangular strip which are arranged perpendicular to each other;

[0011] Both ends of the sixth rectangular strip are connected to the second radiation patch through a third metal column respectively, and the middle part of the sixth rectangular strip is connected to the first radiation metal patch through the second metal column;

[0012] The two third metal pillars are respectively located directly below the two circular holes.

[0013] Further, the second radiation metal patch includes a first T-shaped patch, a second T-shaped patch, a third T-shaped patch, and a fourth T-shaped patch which are arranged along the center of the second dielectric substrate rotated 90° in sequence;

[0014] The first T-shaped patch has the same size as the third T-shaped patch, the second T-shaped patch has the same size as the fourth T-shaped patch, the first T-shaped patch and the second T-shaped patch are connected to each other via a connecting strip, and the first T-shaped patch and the second T-shaped patch connected to each other are connected to the first radiation patch via three first metal pillars;

[0015] The second T-shaped patch and the fourth T-shaped patch are respectively connected to the T-shaped connecting metal sheet through a third metal column.

[0016] Further, the first T-shaped patch and the third T-shaped patch each include a third rectangular strip, and a third fan ring strip connected to an end of the third rectangular strip away from the center of the second dielectric substrate;

[0017] The second T-shaped patch and the fourth T-shaped patch both include a fourth rectangular strip and a fourth fan ring strip connected to an end of the fourth rectangular strip away from the center of the second dielectric substrate;

[0018] A rectangular groove is provided on the fourth rectangular strip of the second T-shaped patch, and two ends of the second PIN diode are respectively connected to the patches on both sides of the rectangular groove.

[0019] Further, the T-shaped radiation patch includes a fifth rectangular strip, and a fifth fan ring strip connected to an end of the fifth rectangular strip away from the center of the second dielectric substrate;

[0020] One end of the fifth rectangular strip close to the center of the second dielectric substrate is connected to the first T-shaped patch and the second T-shaped patch through a third PIN diode.

[0021] Furthermore, it also includes a coaxial line feed, wherein the inner conductor of the coaxial line feed is connected to the first radiation patch, and the outer conductor of the coaxial line feed is connected to the first T-shaped patch and the second T-shaped patch;

[0022] The first radiation patch, the T-shaped connecting metal sheet, the first T-shaped patch, the T-shaped radiation patch and the fourth fan ring strip of the second T-shaped patch are respectively connected to a bias inductor through the first bias patch, the second bias patch, the third bias patch, the fourth bias patch and the fifth bias patch;

[0023] The first dielectric substrate and the second dielectric substrate are both circular dielectric substrates.

[0024] Furthermore, the radius of the first dielectric substrate and the second dielectric substrate is the same, and the radius R1 is 29 mm. The thickness of the first dielectric substrate and the second dielectric substrate is the same, and the thickness h1 is 0.254 mm.

[0025] The distance h2 between the first dielectric substrate and the second dielectric substrate is 8 mm;

[0026] The length L1 of the first paranoid patch is 0.8 mm, the length L2 of the second paranoid patch is 1 mm, the length L3 of the third paranoid patch is 1.2 mm, the length L4 of the fourth paranoid patch is 1.2 mm, and the length L3 of the fifth paranoid patch is 1.2 mm.

[0027] Furthermore, the width of the first rectangular strip and the width of the second rectangular strip are the same, and the width W1 thereof is 8 mm;

[0028] The inner and outer radii of the first fan ring strip and the second fan ring strip are the same, the outer radius R2 is 29 mm, and the inner radius R3 is 25 mm;

[0029] The angle θ1 of the first fan ring strip is 88°, and the angle θ2 of the second fan ring strip is 78°;

[0030] The width W2 of the rectangular annular groove is 0.2 mm, and the diameter φ1 of the circular hole is 0.7 mm;

[0031] The length L6 of the sixth rectangular strip is 8 mm, and the widths of the sixth rectangular strip and the seventh rectangular strip are both W3, and the width W3 is 1.5 mm;

[0032] The diameter φ2 of the first metal column is 0.5 mm, and the diameter φ3 of the third metal column is 0.5 mm;

[0033] The distance g1 between adjacent first metal pillars is 2.8 mm, the distance g2 between the first metal pillar and the third metal pillar is 6 mm, and the distance g3 between the first metal pillar and the center of the second dielectric substrate is 3 mm.

[0034] Furthermore, the third rectangular strip and the fourth rectangular strip have the same width, and their widths W4 are both 8 mm;

[0035] The inner radius R4 of the third fan ring strip is 24 mm, the outer radius R5 of the third fan ring strip is 28 mm, and the angle θ3 of the third fan ring strip is 76°;

[0036] The inner radius R6 of the fourth fan ring strip is 20.5 mm, the outer radius R7 of the fourth fan ring strip is 24.5 mm, and the angle θ4 of the fourth fan ring strip is 71°;

[0037] The spacing g4 between the third T-shaped patch, the fourth T-shaped patch and the connecting strip is 0.25 mm;

[0038] The width W5 of the fifth rectangular strip is 8 mm;

[0039] The inner radius R8 of the fifth fan ring strip is 16.9 mm, the outer radius R9 of the fourth fan ring strip is 19.5 mm, and the angle θ5 of the fifth fan ring strip is 16°.

[0040] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0041] 1. The present invention breaks through the previous reconfigurable directional pattern beam and antenna polarization mode, and realizes the reconfigurable directional pattern of two types: vertically polarized horizontal omnidirectional radiation and circularly polarized broadside radiation.

[0042] 2. The present invention has simple feeding and high integration, and only requires one feeding port and three PIN diodes to realize the functions.

[0043] 3. The present invention has the characteristics of small size, low profile, easy processing and low production cost.

[0044] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings of the present invention are as follows.

[0046] Figure 1 It is a three-dimensional exploded schematic diagram of the antenna of the present invention.

[0047] Figure 2 This is a formal diagram of the antenna of the present invention.

[0048] Figure 3 It is a top view of the first dielectric substrate and the first radiating metal patch of the antenna of the present invention.

[0049] Figure 4 This is a dimensional diagram of the first dielectric substrate and the first radiating metal patch of the antenna of the present invention.

[0050] Figure 5 It is a bottom view of the first dielectric substrate and the T-shaped connecting metal sheet of the antenna of the present invention.

[0051] Figure 6 The figure is a dimension diagram of the first dielectric substrate and the T-shaped connecting metal sheet of the antenna of the present invention.

[0052] Figure 7 It is a bottom view of the second dielectric substrate, the second radiation metal patch and the T-shaped radiation patch of the antenna of the present invention.

[0053] Figure 8 It is a dimension diagram of the second dielectric substrate, the second radiating metal patch and the T-shaped radiating patch of the antenna of the present invention.

[0054] Fig. 9 is the reflection coefficient (|S 11 |) versus frequency.

[0055] Fig.10 This is the radiation pattern of the antenna of the present invention at a frequency of 1.62 GHz when circularly polarized broadside is achieved.

[0056] Fig.11 It is a schematic diagram of the axial ratio curve when the antenna of the present invention realizes circular polarization broadside.

[0057] Fig.12 is the reflection coefficient (|S 11 |) versus frequency.

[0058] Fig.13 This is the radiation pattern of the antenna of the present invention at a frequency of 1.62 GHz when achieving horizontal omnidirectional radiation.

[0059] Fig.14 The figure is a schematic diagram of the radiation efficiency of the antenna of the present invention in two states: circularly polarized broadside radiation and horizontal omnidirectional radiation.

[0060] In the figure: 1-first dielectric substrate; 2-second dielectric substrate; 3-first radiating metal patch; 4-T-type connecting metal patch; 5-second radiating metal patch; 6-T-type radiating patch; 7-first PIN diode; 8-second PIN diode; 9-third PIN diode; 10-coaxial line feeding; 111-first bias patch; 112-second bias patch; 113-third bias patch; 114-fourth bias patch; 115-fifth bias patch; 301-first rectangular strip; 302-second rectangular strip; 303-first fan ring strip; 304-first Two fan ring strips; 305-rectangular ring groove; 306-circular hole; 307-first metal column; 308-second metal column; 401-sixth rectangular strip; 402-seventh rectangular strip; 403-third metal column; 501-first T-shaped patch; 502-second T-shaped patch; 503-third T-shaped patch; 504-fourth T-shaped patch; 505-connecting strip; 601-fifth rectangular strip; 602-fifth fan ring strip; 5011-third rectangular strip; 5012-third fan ring strip; 5021-fourth rectangular strip; 5022-fourth fan ring strip. DETAILED DESCRIPTION

[0061] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0062] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0063] like Figure 1-Figure 5 The multi-element electric small antenna with reconfigurable side-radiating and horizontal omnidirectional patterns comprises a first dielectric substrate 1 and a second dielectric substrate 2 which are arranged parallel to each other;

[0064] A first radiating metal patch 3 is disposed on the upper surface of the first dielectric substrate 1, a T-shaped connecting metal patch 4 is disposed on the lower surface of the first dielectric substrate 1, and a second radiating metal patch 5 and a T-shaped radiating patch 6 are disposed on the lower surface of the second dielectric substrate 2;

[0065] The first radiating metal patch 3 and the T-shaped connecting metal patch 4, the first radiating metal patch 3 and the second radiating metal patch 5, and the T-shaped connecting metal patch 4 and the second radiating metal patch 5 are all connected by metal columns;

[0066] The first radiating metal patch 3 is loaded with a first PIN diode 7, the second radiating metal patch 5 is loaded with a second PIN diode 8, the second radiating metal patch 5 is connected to the T-shaped radiating patch 6 via a third PIN diode 9, and the far-field radiation pattern switching between side radiation and horizontal omnidirectional radiation is achieved by switching the on-off states of the first PIN diode 7, the second PIN diode 8, and the third PIN diode 9.

[0067] As an embodiment of the present invention, the first radiation metal patch 3 includes a first rectangular strip 301 and a second rectangular strip 302 which are orthogonally arranged to each other, both ends of the first rectangular strip 301 are connected to a first fan ring strip 303, and both ends of the second rectangular strip 302 are connected to a second fan ring strip 304;

[0068] The first radiating metal patch 3 is also provided with a rectangular annular groove 305 and two centrally symmetrical circular holes 306. The two ends of the first PIN diode 7 are respectively connected to the patches on both sides of the rectangular annular groove 305. The first radiating metal patch 3 is connected to the second radiating metal patch 5 through three first metal pillars 307. The first radiating metal patch 3 is connected to the T-shaped connecting metal patch 4 through a second metal pillar 308.

[0069] As an embodiment of the present invention, the T-shaped connecting metal sheet 4 includes a sixth rectangular strip 401 and a seventh rectangular strip 402 which are arranged perpendicular to each other;

[0070] Both ends of the sixth rectangular strip 401 are connected to the second radiation patch 5 through a third metal column 403, and the middle of the sixth rectangular strip 401 is connected to the first radiation metal patch 3 through a second metal column 308;

[0071] The two third metal pillars 403 are respectively located directly below the two circular holes 306 .

[0072] As an embodiment of the present invention, the second radiation metal patch 5 includes a first T-shaped patch 501, a second T-shaped patch 502, a third T-shaped patch 503, and a fourth T-shaped patch 504 which are arranged along the center of the second dielectric substrate 2 rotated 90° in sequence;

[0073] The first T-shaped patch 501 has the same size as the third T-shaped patch 503, the second T-shaped patch 502 has the same size as the fourth T-shaped patch 504, the first T-shaped patch 501 and the second T-shaped patch 502 are connected to each other via a connecting strip 505, and the first T-shaped patch 501 and the second T-shaped patch 502 connected to each other are connected to the first radiation patch 3 via three first metal pillars 406;

[0074] The second T-shaped patch 502 and the fourth T-shaped patch 504 are connected to the T-shaped connecting metal sheet 4 via a third metal column 403 respectively.

[0075] As an embodiment of the present invention, the first T-shaped patch 501 and the third T-shaped patch 503 both include a third rectangular strip 5011 and a third fan ring strip 5012 connected to an end of the third rectangular strip 5011 away from the center of the second dielectric substrate 2;

[0076] The second T-shaped patch 502 and the fourth T-shaped patch 504 both include a fourth rectangular strip 5021 and a fourth fan ring strip 5022 connected to an end of the fourth rectangular strip 5021 away from the center of the second dielectric substrate 2;

[0077] A rectangular groove 5023 is formed on the fourth rectangular strip 5021 of the second T-shaped patch 502 , and two ends of the second PIN diode 8 are connected to the patches on both sides of the rectangular groove 5023 .

[0078] As an embodiment of the present invention, the T-shaped radiation patch 6 includes a fifth rectangular strip 601 and a fifth fan ring strip 602 connected to an end of the fifth rectangular strip 601 away from the center of the second dielectric substrate 2;

[0079] One end of the fifth rectangular strip 601 close to the center of the second dielectric substrate 2 is connected to the first T-shaped patch 501 and the second T-shaped patch 502 through the third PIN diode 9 .

[0080] As an embodiment of the present invention, it also includes a coaxial line feed 10, the inner conductor of the coaxial line feed 10 is connected to the first radiation patch 3, and the outer conductor of the coaxial line feed 10 is connected to the first T-shaped patch 501 and the second T-shaped patch 502;

[0081] The first radiation patch 3, the T-shaped connecting metal sheet 4, the first T-shaped patch 501, the T-shaped radiation patch 6 and the fourth fan ring strip 5021 of the second T-shaped patch 502 are connected to a bias inductor through the first bias patch 111, the second bias patch 112, the third bias patch 113, the fourth bias patch 114 and the fifth bias patch 115 respectively;

[0082] The first dielectric substrate 1 and the second dielectric substrate 2 are both circular dielectric substrates.

[0083] In the example of the present invention, when the first PIN diode 7 and the second PIN diode 8 are in the on state and the third PIN diode 9 is in the off state, the odd mode of the antenna is excited, thereby realizing the forward radiation mode; when the first PIN diode 7 and the second PIN diode 8 are in the off state and the third PIN diode 9 is in the on state, the even mode of the antenna is excited, thereby realizing the horizontal omnidirectional radiation mode; the first PIN diode 7, the second PIN diode 8, and the third PIN diode 9 are all PIN diodes with a model of Bar50-02V, and the coaxial line feed 10 uses a 50Ω coaxial line feed.

[0084] According to the above structure, set the parameters as follows:

[0085] The first dielectric substrate 1 and the second dielectric substrate 2 have the same radius, R1 of which is 29 mm, and the first dielectric substrate 1 and the second dielectric substrate 2 have the same thickness, h1 of which is 0.254 mm.

[0086] The distance h2 between the first dielectric substrate 1 and the second dielectric substrate 2 is 8 mm;

[0087] The length L1 of the first paranoid patch 111 is 0.8 mm, the length L2 of the second paranoid patch 112 is 1 mm, the length L3 of the third paranoid patch 113 is 1.2 mm, the length L4 of the fourth paranoid patch 114 is 1.2 mm, and the length L3 of the fifth paranoid patch 115 is 1.2 mm;

[0088] The width of the first rectangular strip 301 and the width of the second rectangular strip 302 are the same, and the width W1 thereof is 8 mm;

[0089] The inner and outer radii of the first fan ring strip 303 and the second fan ring strip 303 are the same, the outer radius R2 is 29 mm, and the inner radius R3 is 25 mm;

[0090] The angle θ1 of the first fan ring strip 303 is 88°, and the angle θ2 of the second fan ring strip 303 is 78°;

[0091] The width W2 of the rectangular annular groove 305 is 0.2 mm, and the diameter φ1 of the circular hole 306 is 0.7 mm;

[0092] The length L6 of the sixth rectangular strip 401 is 8 mm, and the widths of the sixth rectangular strip 401 and the seventh rectangular strip 402 are both W3, and the width W3 is 1.5 mm;

[0093] The diameter φ2 of the first metal column 406 is 0.5 mm, and the diameter φ3 of the third metal column 403 is 0.5 mm;

[0094] The distance g1 between adjacent first metal pillars 406 is 2.8 mm, the distance g2 between the first metal pillar 406 and the third metal pillar 403 is 6 mm, and the distance g3 between the first metal pillar 406 and the center of the second dielectric substrate 2 is 3 mm;

[0095] The third rectangular strip 5011 and the fourth rectangular strip 5021 have the same width, and their widths W4 are both 8 mm;

[0096] The inner radius R4 of the third fan ring strip 5012 is 24 mm, the outer radius R5 of the third fan ring strip 5012 is 28 mm, and the angle θ3 of the third fan ring strip 5012 is 76°;

[0097] The inner radius R6 of the fourth fan ring strip 5022 is 20.5 mm, the outer radius R7 of the fourth fan ring strip 5022 is 24.5 mm, and the angle θ4 of the fourth fan ring strip 5022 is 71°;

[0098] The spacing g4 between the third T-shaped patch 503, the fourth T-shaped patch 504 and the connecting strip 505 is 0.25 mm;

[0099] The width W5 of the fifth rectangular strip 601 is 8 mm;

[0100] The inner radius R8 of the fifth fan ring strip 602 is 16.9 mm, the outer radius R9 of the fourth fan ring strip 5022 is 19.5 mm, and the angle θ5 of the fifth fan ring strip 602 is 16°.

[0101] According to the above parameters, the overall structure of the antenna is simulated and analyzed in the electromagnetic simulation software HFSS. When the first PIN diode 7 and the second PIN diode 8 are in the on state, and the third PIN diode 9 is in the off state, the invented directional pattern reconfigurable antenna realizes circular polarization side radiation. Fig. 9 , 10As shown in Figure 11, its reflection coefficient is lower than -10d B in the frequency range of 1.61 to 1.64GHz, and at the center frequency of 1.62GHz of the two modes, the axial ratio is lower than 2dBi, the maximum achievable gain is 3.9dBi, the radiation efficiency is >75%, and it has good circularly polarized radiation performance.

[0102] When the first PIN diode 7 and the second PIN diode 8 are in the cut-off state and the third PIN diode 9 is in the on state, the invented directional pattern reconfigurable antenna realizes horizontal omnidirectional radiation. Fig.12 , 13 As shown, its reflection coefficient is lower than -10d B in the frequency range of 1.61 to 1.63GHz. At the center frequency of 1.62GHz of the two modes, the maximum achievable gain is 1.7dBi, the radiation efficiency is >94%, and it has good radiation performance.

[0103] like Fig.14 As shown, the solid line in the figure is the radiation efficiency curve within the passband of the horizontal omnidirectional radiation mode, and the dotted line in the figure is the radiation efficiency curve within the passband of the circularly polarized edge-emitting mode.

[0104] In summary, the present invention has the characteristics of small size and low profile. When using one feeding port, it can realize the switching of horizontal omnidirectional radiation and broadside radiation pattern only by turning on and off three PIN diodes, accompanied by the conversion of vertical linear polarization and circular polarization states, and has good radiation performance.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A multi-element electric small antenna with reconfigurable side-firing and horizontal omnidirectional patterns, characterized in that: It comprises a first dielectric substrate (1) and a second dielectric substrate (2) which are arranged parallel to each other; A first radiating metal patch (3) is provided on the upper surface of the first dielectric substrate (1), a T-shaped connecting metal patch (4) is provided on the lower surface of the first dielectric substrate (1), and a second radiating metal patch (5) and a T-shaped radiating patch (6) are provided on the lower surface of the second dielectric substrate (2); The first radiating metal patch (3) and the T-shaped connecting metal patch (4), the first radiating metal patch (3) and the second radiating metal patch (5), and the T-shaped connecting metal patch (4) and the second radiating metal patch (5) are all connected via metal columns; The first radiating metal patch (3) is loaded with a first PIN diode (7), the second radiating metal patch (5) is loaded with a second PIN diode (8), the second radiating metal patch (5) is connected to the T-shaped radiating patch (6) via a third PIN diode (9), and the switching of the far-field directivity patterns of side radiation and horizontal omnidirectional radiation is achieved by switching the on and off states of the first PIN diode (7), the second PIN diode (8), and the third PIN diode (9); The first radiation metal patch (3) comprises a first rectangular strip (301) and a second rectangular strip (302) which are arranged orthogonally to each other, both ends of the first rectangular strip (301) are connected to a first fan ring strip (303), and both ends of the second rectangular strip (302) are connected to a second fan ring strip (304); The first radiating metal patch (3) is also provided with a rectangular annular groove (305) and two centrally symmetrical circular holes (306); the two ends of the first PIN diode (7) are respectively connected to the patches on both sides of the rectangular annular groove (305); the first radiating metal patch (3) is connected to the second radiating metal patch (5) via three first metal pillars (307); and the first radiating metal patch (3) is connected to the T-shaped connecting metal patch (4) via a second metal pillar (308); The T-shaped connecting metal sheet (4) comprises a sixth rectangular strip (401) and a seventh rectangular strip (402) which are arranged perpendicular to each other; The two ends of the sixth rectangular strip (401) are respectively connected to the second radiation patch (5) via a third metal column (403), and the middle part of the sixth rectangular strip (401) is connected to the first radiation metal patch (3) via a second metal column (308); The two third metal pillars (403) are respectively located directly below the two circular holes (306); The second radiation metal patch (5) comprises a first T-shaped patch (501), a second T-shaped patch (502), a third T-shaped patch (503), and a fourth T-shaped patch (504) which are arranged in sequence and rotated 90 degrees along the center of the second dielectric substrate (2); The first T-shaped patch (501) and the third T-shaped patch (503) have the same size, the second T-shaped patch (502) and the fourth T-shaped patch (504) have the same size, the first T-shaped patch (501) and the second T-shaped patch (502) are connected to each other via a connecting strip (505), and the first T-shaped patch (501) and the second T-shaped patch (502) connected to each other are connected to the first radiation patch (3) via three first metal pillars (307); The second T-shaped patch (502) and the fourth T-shaped patch (504) are respectively connected to the T-shaped connecting metal sheet (4) via a third metal column (403); The first T-shaped patch (501) and the third T-shaped patch (503) both comprise a third rectangular strip (5011) and a third fan ring strip (5012) connected to an end of the third rectangular strip (5011) away from the center of the second dielectric substrate (2); The second T-shaped patch (502) and the fourth T-shaped patch (504) both comprise a fourth rectangular strip (5021) and a fourth fan ring strip (5022) connected to an end of the fourth rectangular strip (5021) away from the center of the second dielectric substrate (2); A rectangular groove (5023) is provided on the fourth rectangular strip (5021) of the second T-shaped patch (502), and two ends of the second PIN diode (8) are respectively connected to the patches on both sides of the rectangular groove (5023); The T-shaped radiation patch (6) comprises a fifth rectangular strip (601) and a fifth fan ring strip (602) connected to an end of the fifth rectangular strip (601) away from the center of the second dielectric substrate (2); One end of the fifth rectangular strip (601) close to the center of the second dielectric substrate (2) is connected to the first T-shaped patch (501) and the second T-shaped patch (502) via a third PIN diode (9).

2. The multi-element electric small antenna with reconfigurable side-fire and horizontal omnidirectional patterns as claimed in claim 1, characterized in that: It also includes a coaxial line feed (10), wherein the inner conductor of the coaxial line feed (10) is connected to the first radiation patch (3), and the outer conductor of the coaxial line feed (10) is connected to the first T-shaped patch (501) and the second T-shaped patch (502); The first radiation patch (3), the T-shaped connecting metal sheet (4), the first T-shaped patch (501), the T-shaped radiation patch (6), and the fourth fan ring strip (5022) of the second T-shaped patch (502) are respectively connected to a bias inductor via a first bias patch (111), a second bias patch (112), a third bias patch (113), a fourth bias patch (114), and a fifth bias patch (115); The first dielectric substrate (1) and the second dielectric substrate (2) are both circular dielectric substrates.

3. The multi-element electric small antenna with reconfigurable side-fire and horizontal omnidirectional patterns as claimed in claim 2, characterized in that: The radius of the first dielectric substrate (1) and the second dielectric substrate (2) are the same, and the radius R1 is 29 mm; the thickness of the first dielectric substrate (1) and the second dielectric substrate (2) are the same, and the thickness h1 is 0.254 mm; The distance h2 between the first dielectric substrate (1) and the second dielectric substrate (2) is 8 mm; The length L1 of the first bias patch (111) is 0.8 mm, the length L2 of the second bias patch (112) is 1 mm, the length L3 of the third bias patch (113) is 1.2 mm, the length L4 of the fourth bias patch (114) is 1.2 mm, and the length L3 of the fifth bias patch (115) is 1.2 mm.

4. The multi-element electric small antenna with reconfigurable side-fire and horizontal omnidirectional patterns as claimed in claim 3, characterized in that: The width of the first rectangular strip (301) and the width of the second rectangular strip (302) are the same, and the width W1 of both is 8 mm; The inner and outer radii of the first fan ring strip (303) and the second fan ring strip (304) are the same, their outer radii R2 are both 29 mm, and their inner radii R3 are both 25 mm; The angle θ1 of the first fan ring strip (303) is 88°, and the angle θ2 of the second fan ring strip (304) is 78°; The width W2 of the rectangular annular groove (305) is 0.2 mm, and the diameter of the circular hole (306) is 0.7 mm; The length L6 of the sixth rectangular strip (401) is 8 mm, and the widths of the sixth rectangular strip (401) and the seventh rectangular strip (402) are both W3, and the width W3 is 1.5 mm; The diameter of the first metal column (307) is 0.5 mm, and the diameter of the third metal column (403) is 0.5 mm; The spacing g1 between adjacent first metal pillars (307) is 2.8 mm, the spacing g2 between the first metal pillar (307) and the third metal pillar (403) is 6 mm, and the spacing g3 between the first metal pillar (307) and the center of the second dielectric substrate (2) is 3 mm.

5. The multi-element electric small antenna with reconfigurable side-beam and horizontal omnidirectional patterns as claimed in claim 4, characterized in that: The third rectangular strip (5011) and the fourth rectangular strip (5021) have the same width, and their widths W4 are both 8 mm; The inner radius R4 of the third fan ring strip (5012) is 24 mm, the outer radius R5 of the third fan ring strip (5012) is 28 mm, and the angle θ3 of the third fan ring strip (5012) is 76°; The inner radius R6 of the fourth fan ring strip (5022) is 20.5 mm, the outer radius R7 of the fourth fan ring strip (5022) is 24.5 mm, and the angle θ4 of the fourth fan ring strip (5022) is 71°; The spacing g4 between the third T-shaped patch (503), the fourth T-shaped patch (504) and the connecting strip (505) is 0.25 mm; The width W5 of the fifth rectangular strip (601) is 8 mm; The inner radius R8 of the fifth fan ring strip (602) is 16.9 mm, the outer radius R9 of the fourth fan ring strip (5022) is 19.5 mm, and the angle θ5 of the fifth fan ring strip (602) is 16°.

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