A 5G filter antenna with multiple radiation nulls and low cross-polarization

Abstract

The present invention discloses a 5G filtering antenna with multiple radiation zero points and low cross polarization. The specific scheme includes: an upper square metal patch, an upper dielectric substrate, a middle square metal patch, a lower dielectric substrate, a lower square metal floor, a feeding connector, a long metal shorting pin and a short metal shorting pin. The filtering antenna generates multiple radiation zero points through the coupling between the radiation slot and the coupling slot, thereby improving the frequency selectivity; by introducing the short metal shorting pin to form two left and right cavities, the out-of-band suppression performance of the filtering antenna is improved, and low cross polarization is achieved through the inner conductor feeding probe in the left cavity. In addition, the filtering antenna also has the advantages of compact structure, low profile, light weight, flexible adjustment of bandwidth and radiation zero point position, etc., which is very suitable for the application of my country's 5G communication system.

Description

Technical Field

[0001] The present invention relates to a filtering antenna, in particular to a 5G filtering antenna with high frequency selectivity, low cross polarization and multiple radiation zero points. Background Art

[0002] As a new type of RF front-end equipment, the filter antenna integrates the antenna for transmitting and receiving electromagnetic wave signals with the bandpass filter for frequency selection. It has both filtering and radiation functions. It realizes the miniaturization, low cost and low loss of RF front-end equipment. It plays a great role in the fifth-generation mobile communication system and has extremely high research value.

[0003] Substrate integrated waveguide (SIW) technology is a technology that inserts metal short-circuit pins into a dielectric substrate with metal plates on the top and bottom. It has a planar structure similar to a microstrip line and is easy to integrate with other planar circuits. However, it has a lower cost when applied to high-frequency fields because it can reduce dielectric loss and suppress surface wave loss. Due to its advantages of low insertion loss and radiation loss, substrate integrated waveguides are often used in the research of high-performance filters and antennas. In recent years, many SIW filter antennas have also been proposed. However, the existing research lacks designs that have both high frequency selectivity and good radiation directivity, and the number of radiation zero points is small, which makes it difficult to meet the needs of the fifth-generation mobile communication system. Summary of the invention

[0004] According to the problems existing in the prior art, the present invention discloses a 5G filtering antenna with high frequency selectivity, low cross polarization and multiple radiation zero points. The specific scheme includes: an upper square metal patch, an upper dielectric substrate, a middle square metal patch, a lower dielectric substrate, a lower square metal floor, a feed connector, a long metal short-circuit pin and a short metal short-circuit pin;

[0005] The upper square metal patch is located on the upper surface of the upper dielectric substrate, and the upper square metal patch is provided with a radiation gap I and a radiation gap II;

[0006] The middle-layer square metal patch is located on the upper surface of the lower dielectric substrate, and the middle-layer square metal patch is provided with a coupling gap I and a coupling gap II;

[0007] The lower square metal floor is located on the lower surface of the lower dielectric substrate;

[0008] The long metal short-circuit needle passes through the upper dielectric substrate and the lower dielectric substrate in sequence from top to bottom, and connects the upper square metal patch, the middle square metal patch and the lower square metal floor in sequence;

[0009] The short metal short-circuit needle is located on the vertical center line of the upper dielectric substrate and penetrates the upper dielectric substrate to form two left and right cavities;

[0010] The feeding connector comprises an inner conductor feeding probe and an outer conductor. The inner conductor feeding probe sequentially penetrates the upper dielectric substrate and the lower dielectric substrate from top to bottom and is connected to the upper square metal patch and the middle square metal patch. The outer conductor is connected to the lower square metal floor.

[0011] The upper dielectric substrate is tightly fitted to the lower dielectric substrate, and the upper dielectric substrate and the lower dielectric substrate are fixedly connected via the long metal short-circuit pins.

[0012] The working bandwidth and the position of the radiation zero point are adjusted by adjusting the sizes of the radiation slot I, the radiation slot II, the coupling slot I, and the coupling slot II and the distances from the center of the filtering antenna.

[0013] The position of the feeding connector is adjustable, and the radiation of the cross-polarized wave is reduced by changing the position of the feeding connector.

[0014] The coupling between the radiation slot I and the coupling slot I generates two radiation zero points on the right side of the passband and improves the frequency selectivity on the right side of the passband; the coupling between the radiation slot II and the coupling slot II generates a radiation zero point on the left side of the passband and improves the frequency selectivity on the left side of the passband.

[0015] The out-of-band suppression performance of the filtering antenna is improved by forming the left and right cavities by the short metal short-circuit pins.

[0016] Due to the adoption of the above technical scheme, the present invention provides a 5G filtering antenna with high frequency selectivity, low cross-polarization and multiple radiation zero points. The structure generates multiple radiation zero points through the coupling between the radiation slot and the coupling slot, thereby improving the frequency selectivity; by introducing a short metal short-circuit needle to form two left and right cavities, the out-of-band suppression performance of the filtering antenna is improved; and low cross-polarization is achieved through the inner conductor feeding probe in the left cavity; the double-layer dielectric substrate of the structure fits tightly, reducing the cross-section of the 5G filtering antenna; it also has the advantages of compact structure, small size, light weight, flexible adjustment of bandwidth and radiation zero point position, etc., and is very suitable for the application of my country's 5G communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a structural exploded diagram of a 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention;

[0019] Figure 2 This is a structural diagram of the upper square metal patch of the 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention;

[0020] Figure 3 This is a structural diagram of a middle-layer square metal patch of a 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention;

[0021] Figure 4 The S parameters and gain curve diagram of the 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention;

[0022] Figure 5 It is the normalized directivity diagram at the center frequency of the 5G filtering antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention. DETAILED DESCRIPTION

[0023] In order to make the technical solutions and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention:

[0024] like Figure 1 A 5G filtering antenna with high frequency selectivity, low cross-polarization and multiple radiation zero points is shown, including an upper square metal patch 1, an upper dielectric substrate 2, a middle square metal patch 3, a lower dielectric substrate 4, a lower square metal floor 5, a feeding connector 6, a long metal short-circuit pin 7 and a short metal short-circuit pin 8.

[0025] Further, such as Figure 2 and Figure 3As shown, the upper square metal patch 1 is located on the upper surface of the upper dielectric substrate 2; the upper square metal patch 1 is provided with a radiation gap I11 and a radiation gap II12; the middle square metal patch 3 is located on the upper surface of the lower dielectric substrate 4; the middle square metal patch 3 is provided with a coupling gap I31 and a coupling gap II32. The lower square metal floor 5 is located on the lower surface of the lower dielectric substrate 4; the long metal short-circuit needle 7 passes through the upper dielectric substrate 2 and the lower dielectric substrate 4 from top to bottom, and connects the upper square metal patch 1, the middle square metal patch 3 and the lower square metal floor 5.

[0026] Furthermore, the short metal short-circuit pin 8 is located on the vertical center line of the upper dielectric substrate 2 and penetrates the upper dielectric substrate 2, thereby forming two left and right cavities; the feeding connector 6 includes an inner conductor feeding probe 61 and an outer conductor 62; the inner conductor feeding probe 61 penetrates the upper dielectric substrate 2 and the lower dielectric substrate 4 from top to bottom in sequence, and is connected to the upper square metal patch 1 and the middle square metal patch 3; the outer conductor 62 is connected to the lower square metal floor 5.

[0027] Furthermore, the upper dielectric substrate 2 is tightly fitted to the lower dielectric substrate 4 , and the upper dielectric substrate 2 and the lower dielectric substrate 4 are fixedly connected via the long metal short-circuit pin 7 .

[0028] Furthermore, by adjusting the sizes of the radiation slot I11, the radiation slot II12, the coupling slot I31, and the coupling slot II32 and their distances from the center of the filtering antenna, the working bandwidth and the position of the radiation zero point are adjusted.

[0029] Furthermore, the position of the feed connector 6 is adjustable, and the radiation of the cross-polarized wave is reduced by changing the position of the feed connector 6;

[0030] Furthermore, the coupling between the radiation slot I11 and the coupling slot I31 generates two radiation zero points on the right side of the passband and improves the frequency selectivity on the right side of the passband; the coupling between the radiation slot II12 and the coupling slot II32 generates a radiation zero point on the left side of the passband and improves the frequency selectivity on the left side of the passband;

[0031] Furthermore, the left and right cavities formed by the short metal short-circuit pin 8 improve the out-of-band suppression performance of the filtering antenna.

[0032] Figure 4 The S parameter amplitude and gain parameter curve of the 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention. Figure 4It can be seen that the center frequency of the filtering antenna is 3.5 GHz, and the impedance bandwidth is 6.8% (3.38 GHz-3.62 GHz); the gain curve has three radiation zero points, which are located at 3.27 GHz, 3.68 GHz and 4.68 GHz, respectively, which improves the filtering performance; the gain is 5.94 dBi at the center frequency of 3.5 GHz, and the left and right frequency band selectivities of the antenna are 293.6 dB / GHz and 459 dB / GHz, respectively; this shows that the 5G filtering antenna provided by the present invention has the characteristics of multiple radiation zero points and high frequency selectivity.

[0033] Figure 5 It is the normalized directivity diagram at the center frequency (3.5GHz) of the 5G filtering antenna with high frequency selectivity, low cross polarization and multiple radiation zero points of the present invention. Figure 5 It can be seen that the cross-polarization waves within the half-power beamwidth of the E-plane and H-plane of the antenna are respectively 50dB and 33dB lower than the main polarization waves, showing excellent cross-polarization suppression performance.

[0034] In summary, the present invention provides a 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zero points. The filter antenna generates multiple radiation zero points through the coupling between the radiation slot and the coupling slot, thereby improving the frequency selectivity; by introducing a short metal short-circuit needle to form two left and right cavities, the out-of-band suppression performance of the filter antenna is improved, and low cross polarization is achieved through the inner conductor feeding probe in the left cavity. In addition, the filter antenna also has the advantages of compact structure, low profile, light weight, flexible adjustment of bandwidth and radiation zero position, etc., which is very suitable for the application of my country's 5G communication system.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A 5G filter antenna with high frequency selectivity, low cross polarization and multiple radiation zeros, characterized in that include: An upper square metal patch (1), an upper dielectric substrate (2), a middle square metal patch (3), a lower dielectric substrate (4), a lower square metal floor (5), a feed connector (6), a long metal short-circuit pin (7) and a short metal short-circuit pin (8); The upper square metal patch (1) is located on the upper surface of the upper dielectric substrate (2), and a radiation gap I (11) and a radiation gap II (12) are provided on the upper square metal patch (1); The middle-layer square metal patch (3) is located on the upper surface of the lower-layer dielectric substrate (4), and a coupling gap I (31) and a coupling gap II (32) are provided on the middle-layer square metal patch (3); The lower square metal floor (5) is located on the lower surface of the lower dielectric substrate (4); The long metal short-circuit needle (7) passes through the upper dielectric substrate (2) and the lower dielectric substrate (4) in sequence from top to bottom, and sequentially connects the upper square metal patch (1), the middle square metal patch (3) and the lower square metal floor (5); The short metal short-circuit needle (8) is located on the vertical center line of the upper dielectric substrate (2) and penetrates the upper dielectric substrate (2) to form two left and right cavities; The feeding connector (6) comprises an inner conductor feeding probe (61) and an outer conductor (62), wherein the inner conductor feeding probe (61) sequentially penetrates the upper dielectric substrate (2) and the lower dielectric substrate (4) from top to bottom and is connected to the upper square metal patch (1) and the middle square metal patch (3), and the outer conductor (62) is connected to the lower square metal floor (5); The working bandwidth and the position of the radiation zero point are adjusted by adjusting the sizes of the radiation slot I (11), the radiation slot II (12), the coupling slot I (31), and the coupling slot II (32) and their distances from the center of the filtering antenna; Reducing the radiation of cross-polarized waves by changing the position of the feed connector (6); The coupling between the radiation slot I (11) and the coupling slot I (31) generates two radiation zero points on the right side of the passband and improves the frequency selectivity on the right side of the passband; the coupling between the radiation slot II (12) and the coupling slot II (32) generates a radiation zero point on the left side of the passband and improves the frequency selectivity on the left side of the passband.

2. The 5G filtering antenna according to claim 1, characterized in that: The upper dielectric substrate (2) is tightly fitted to the lower dielectric substrate (4), and the upper dielectric substrate (2) and the lower dielectric substrate (4) are fixedly connected via the long metal short-circuit pin (7).

3. The 5G filtering antenna according to claim 1, characterized in that: The two left and right cavities formed by the short metal short-circuit needle (8) improve the out-of-band suppression performance of the filtering antenna.

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