Wideband wearable filter antenna with high out-of-band suppression level and wireless communication device

Abstract

The present invention discloses a broadband wearable filtering antenna and wireless communication device with high out-of-band suppression. The antenna is composed of two layers of flexible dielectric substrates (first and second dielectric substrates) and is made of polydimethylsiloxane. A rectangular radiating patch is loaded on the upper surface of the first dielectric substrate, and a radiation zero point is introduced at low frequency by loading an open annular groove. A high-frequency radiation zero point is introduced by loading a T-shaped strip on the upper surface of the second dielectric substrate. The high-frequency out-of-band suppression level is improved by loading transverse and longitudinal rectangular grooves on the rectangular radiating patch. The loading of the open annular groove and the T-shaped strip widens the bandwidth. The antenna is of an overall flexible design, suitable for wearable devices, and still meets performance requirements after loading a human tissue model. The present invention simultaneously achieves high out-of-band suppression and broadband filtering performance.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, and in particular to a broadband wearable filtering antenna with a high out-of-band suppression level and a wireless communication device. Background Art

[0002] With the rapid development of wireless communication technology, users are increasingly demanding smaller, more versatile, and higher-performance communication devices. To meet these demands, filter antennas have emerged as an emerging technology. However, existing filter antenna designs often focus on rigid substrates, making them difficult to meet the flexibility, lightweight, and radiation safety requirements of wearable devices. The development of wearable filter antennas could help address this issue. Summary of the Invention

[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a broadband wearable filtering antenna with high out-of-band suppression level, which can have good broadband characteristics and stable gain while meeting wearable requirements, and has high out-of-band suppression level characteristics, thereby achieving high out-of-band suppression level and broadband performance.

[0004] A second object of the present invention is to provide a wireless communication device.

[0005] The first objective of the present invention is achieved through the following technical solution: a broadband wearable filter antenna with a high out-of-band suppression level, comprising a first dielectric substrate, a second dielectric substrate, a ground plane, a rectangular radiating patch, a longitudinal rectangular slot, an open annular slot, a transverse rectangular slot, a coaxial probe, and a T-shaped strip; the first dielectric substrate is stacked on the second dielectric substrate, the rectangular radiating patch is arranged on the upper surface of the first dielectric substrate, the open annular slot is located below the center of the rectangular radiating patch, and is used to generate a low-frequency radiation null point and a new resonance point and widen the matching bandwidth; the transverse rectangular slot is located inside the open annular slot and is used to change the high-frequency out-of-band current distribution; the longitudinal rectangular slot is located on the left and right sides of the open annular slot and close to the left and right sides of the rectangular radiating patch, and is used to bring the TM20 mode resonance point closer to the passband; the T-shaped strip is arranged on the upper surface of the second dielectric substrate and is used to generate a high-frequency radiation null point and widen the matching bandwidth; the ground plane is arranged on the lower surface of the second dielectric substrate; the rectangular radiating patch and the T-shaped strip are connected by a coaxial probe.

[0006] Preferably, the length of the open annular groove is half the wavelength corresponding to the low-frequency radiation zero-point frequency. By controlling the length of the open annular groove, the left-right movement of the low-frequency radiation zero-point can be controlled.

[0007] Preferably, the longitudinal length of the T-shaped strip plus half of its transverse length is a quarter wavelength corresponding to the high-frequency radiation zero point frequency. By controlling the length of the T-shaped strip, the left and right movement of the high-frequency radiation zero point can be controlled.

[0008] Preferably, the ground, rectangular radiation patch, open annular groove, transverse rectangular groove, and T-shaped strip are bilaterally symmetrical structures about the center line of the dielectric substrate.

[0009] Preferably, the longitudinal rectangular grooves on the left and right sides of the open annular groove are bilaterally symmetrical with respect to the center line of the dielectric substrate.

[0010] Preferably, the opening of the open annular groove faces the upper edge of the rectangular radiation patch.

[0011] Preferably, the rectangular radiation patch is located in the middle of the upper surface of the first dielectric substrate.

[0012] Preferably, the medium used for the first dielectric substrate and the second dielectric substrate is flexible and bendable polydimethylsiloxane (PDMS), with a dielectric constant of 2.7 and a loss tangent of 0.013.

[0013] Preferably, the materials of the ground, rectangular radiation patch and T-shaped strip are all conductive nylon fabric with a surface resistivity of less than 0.009Ω / m 2 .

[0014] Preferably, the first dielectric substrate and the second dielectric substrate are equal in size and are both cubes.

[0015] Preferably, the ground covers the entire lower surface of the second dielectric substrate.

[0016] The second object of the present invention is achieved through the following technical solution: a wireless communication device includes the above-mentioned broadband wearable filtering antenna with a high out-of-band suppression level.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] 1. The antenna of the present invention introduces a radiation null at low frequencies and a new resonance point by loading an open annular slot on a rectangular radiation patch, thereby achieving filtering performance at low frequencies while broadening the bandwidth. By loading a T-shaped strip, a radiation null is introduced at high frequencies while further broadening the bandwidth. By loading longitudinal rectangular slots on both sides of the open annular slot and transverse rectangular slots inside the open annular slot, high-frequency filtering performance can be effectively improved, ultimately achieving both broadband and high out-of-band suppression performance.

[0019] 2. The antenna of the present invention combines open annular slots, transverse rectangular slots, and longitudinal rectangular slots on a rectangular radiating patch with T-shaped strips on a second dielectric substrate to achieve a broadband wearable filter antenna with high out-of-band suppression. The antenna has an impedance bandwidth of 22.42% (3.05-3.82 GHz), an average gain of 5.9 dBi within the passband, and a peak gain of 6.3 dBi within the passband. At 2.3 and 4.78 GHz, two radiation nulls with gains below -35.2 and -47.75 dB are introduced on the gain curve. Low-frequency out-of-band suppression exceeds 35.3 dB, and high-frequency out-of-band suppression exceeds 40.3 dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of a broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0021] Figure 2 This is a top view of the first dielectric substrate of the broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0022] Figure 3 This is a top view of the second dielectric substrate of the broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0023] Figure 4 FIG4 is an S-parameter diagram of a broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0024] Figure 5 FIG. 4 is a gain curve diagram of a broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0025] Figure 6 FIG. 4 is an efficiency curve of a broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0026] Figure 7 This is the E-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 3.2 GHz according to an embodiment of the present invention.

[0027] Figure 8 This is the H-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 3.2 GHz according to an embodiment of the present invention.

[0028] Figure 9 This is the E-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 3.7 GHz according to an embodiment of the present invention.

[0029] Figure 10 This is the H-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 3.7 GHz according to an embodiment of the present invention.

[0030] Figure 11 This is the E-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 2.3 GHz according to an embodiment of the present invention.

[0031] Figure 12 This is the H-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 2.3 GHz according to an embodiment of the present invention.

[0032] Figure 13 This is the E-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 4.78 GHz according to an embodiment of the present invention.

[0033] Figure 14 This is the H-plane radiation field pattern of the broadband wearable filtering antenna with high out-of-band suppression level at 4.78 GHz according to an embodiment of the present invention.

[0034] Figure 15 This is a schematic structural diagram of a broadband wearable filtering antenna with high out-of-band suppression level loaded with a three-layer human tissue model according to an embodiment of the present invention.

[0035] Figure 16 The S-parameter diagram of a three-layer human tissue model loaded with a broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention.

[0036] Figure 17 SAR value diagram of a three-layer human tissue model loaded with a broadband wearable filtering antenna with high out-of-band suppression level according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] Currently, wearable antennas have the problems of large size, low integration and single function. Integrating a wearable antenna and a filter into a wearable filter antenna can make the antenna have both radiation and filtering performance while meeting the wearable requirements, which is conducive to the miniaturization and multi-function of the wearable antenna. Therefore, this embodiment provides a broadband wearable filter antenna with high out-of-band suppression level, see Figures 1 to 3As shown, it comprises a first dielectric substrate 1, a second dielectric substrate 2, a ground 3, a rectangular radiating patch 4, a longitudinal rectangular groove 5, an open annular groove 6, a transverse rectangular groove 7, a coaxial probe 8 and a T-shaped strip 9; the first dielectric substrate 1 is stacked on the second dielectric substrate 2, the rectangular radiating patch 4 is arranged in the middle position of the upper surface of the first dielectric substrate 1, the open annular groove 6 is located below the middle of the rectangular radiating patch 4, and its opening faces the upper edge of the rectangular radiating patch 4, the transverse rectangular groove 7 is located inside the open annular groove 6, the longitudinal rectangular groove 5 is located on the left and right sides of the open annular groove 6, and is close to the left and right sides of the rectangular radiating patch 4, the T-shaped strip 9 is arranged on the upper surface of the second dielectric substrate 2, the ground 3 is arranged on the lower surface of the second dielectric substrate 2, and the rectangular radiating patch 4 and the T-shaped strip 9 are connected via the coaxial probe 8.

[0040] This embodiment generates a low-frequency radiation zero point and a new resonance point by loading an open annular groove 6 on the rectangular radiation patch 4, thereby widening the matching bandwidth. The length of the open annular groove 6 is half the wavelength corresponding to the frequency of the low-frequency radiation zero point. By controlling the length of the open annular groove 6, the left and right movement of the low-frequency radiation zero point can be controlled.

[0041] Furthermore, a radiation zero point is introduced at high frequency by setting a T-shaped strip 9 on the upper surface of the second dielectric substrate 2, and the matching bandwidth is further widened. The longitudinal length of the T-shaped strip 9 plus half of the transverse length is a quarter wavelength corresponding to the high-frequency radiation zero point frequency. By controlling the length of the T-shaped strip 9, the left and right movement of the high-frequency radiation zero point can be controlled.

[0042] Furthermore, by adding longitudinal rectangular slots 5 on the left and right sides of the open annular slot 6, the TM20 mode resonance point is moved closer to the passband, thereby improving the high frequency out-of-band suppression level and enhancing the high frequency selectivity.

[0043] Furthermore, by adding a transverse rectangular groove 7 inside the open annular groove 6, the high-frequency out-of-band current distribution is changed, and the out-of-band suppression level is further improved.

[0044] Preferably, the ground 3, rectangular radiation patch 4, open annular groove 6, transverse rectangular groove 7, and T-shaped strip 9 are bilaterally symmetrical with respect to the center line of the dielectric substrate.

[0045] Preferably, the longitudinal rectangular grooves 5 on the left and right sides of the open annular groove 6 are bilaterally symmetrical with respect to the center line of the dielectric substrate.

[0046] Preferably, the medium used for the first dielectric substrate 1 and the second dielectric substrate 2 is flexible and bendable polydimethylsiloxane (PDMS), with a dielectric constant of 2.7 and a loss tangent of 0.013.

[0047] Preferably, the material of the ground 3, rectangular radiation patch 4 and T-shaped strip 9 are all conductive nylon fabrics with a surface resistivity of less than 0.009Ω / m 2 .

[0048] Preferably, the first dielectric substrate 1 and the second dielectric substrate 2 are equal in size and are both cubes.

[0049] Preferably, the ground 3 covers the entire lower surface of the second dielectric substrate 2 .

[0050] See also Figure 4 As shown in FIG. 1 , this is an S parameter simulation curve diagram of the broadband wearable filtering antenna with high out-of-band suppression level in this embodiment. From the figure, we can see that the antenna's |S 11 |<-10dB bandwidth is 3.05-3.82GHz, 22.42%, applied to the 3.5GHz WiMAX band (3.4-3.6GHz).

[0051] See also Figure 5 Figure 2 shows a simulated gain curve for the broadband wearable filter antenna with high out-of-band rejection in this embodiment. The average in-band gain is 5.9 dBi, and the peak gain in the passband is 6.3 dBi. At 2.3 and 4.78 GHz, two radiation nulls with gains below -35.2 and -47.75 dB are introduced into the gain curve. The low-frequency out-of-band rejection level exceeds 35.3 dB, and the high-frequency out-of-band rejection level exceeds 40.3 dB.

[0052] See also Figure 6 As shown in FIG. , this is the efficiency curve of the broadband wearable filtering antenna with a high out-of-band suppression level in this embodiment. The average efficiency within the band is 84%, and the efficiency drops rapidly outside the band.

[0053] See also Figure 7 and Figure 8 As shown in FIG. 1 , the E-plane radiation field pattern and H-plane radiation field pattern of the broadband wearable filter antenna with high out-of-band suppression level at 3.2 GHz are shown. As can be seen from the figure, the antenna has good directional radiation characteristics at this frequency, and the cross-polarization is less than -10 dB.

[0054] See also Figure 9 and Figure 10 As shown in FIG. 1 , the E-plane radiation field pattern and H-plane radiation field pattern of the broadband wearable filter antenna with high out-of-band suppression level at 3.7 GHz are shown. As can be seen from the figure, the antenna has good directional radiation characteristics at this frequency point, and the cross-polarization is less than -10 dB.

[0055] See also Figure 11 and Figure 12As shown in FIG. 1 , the E-plane radiation field pattern and H-plane radiation field pattern of the broadband wearable filter antenna with high out-of-band suppression level at 2.3 GHz are shown. It can be seen from the figure that the antenna does not radiate at this frequency, and both the main polarization and cross polarization are less than -10 dB.

[0056] See also Figure 13 and Figure 14 As shown in FIG. 1 , the E-plane radiation field pattern and H-plane radiation field pattern of the broadband wearable filter antenna with high out-of-band suppression level at 4.78 GHz are shown. It can be seen from the figure that the antenna does not radiate at this frequency, and both the main polarization and cross polarization are less than -30 dB.

[0057] See also Figure 15 The figure shows the structure of the broadband wearable filter antenna with high out-of-band suppression level in this embodiment loaded with a three-layer human tissue model. The three-layer human tissue model is loaded to simulate the impact of human body loading on antenna performance and to evaluate whether the antenna's radiation to the human body meets safety standards.

[0058] See also Figure 16 Figure 2 shows the S-parameters of the broadband wearable filter antenna with high out-of-band suppression in this embodiment, loaded with a three-layer human tissue model. As can be seen from the figure, after loading the three layers of human tissue, the bandwidth narrows somewhat, to 3.13-3.85 GHz, a 20.63% decrease. However, it still covers the 3.5 GHz WiMAX band, meeting usage requirements.

[0059] See also Figure 17 Figure 2 shows the SAR value of the broadband wearable filter antenna with high out-of-band suppression in this embodiment, loaded onto a three-layer human tissue model. As can be seen from the figure, the antenna's maximum SAR value is 0.061 W / kg, far below the international safety standard of 1.6 W / kg.

[0060] In summary, the present invention introduces a radiation zero point at low frequency by loading an open annular groove on a rectangular radiation patch, thereby generating a new resonance point. Combined with the original resonance point of the rectangular radiation patch, the bandwidth is widened. The length of the open annular groove is approximately half the wavelength corresponding to the center frequency of the low-frequency radiation zero point. The position of the zero point can be controlled by controlling the length of the open annular groove. In addition, by loading a T-shaped strip, the bandwidth is further widened while introducing a radiation zero point at high frequency. The longitudinal length of the T-shaped strip plus half of the transverse length is a quarter wavelength corresponding to the high-frequency radiation zero point frequency. The position of the high-frequency radiation zero point can be controlled by controlling the length of the T-shaped strip. The loading of transverse and longitudinal rectangular grooves further improves the high-frequency out-of-band suppression level and improves the filtering characteristics. And subsequently, by loading a three-layer human tissue model, it can be ensured that the antenna can maintain normal operating performance when integrated with the human body. Finally, |S was achieved. 11|<-10dB bandwidth is 3.05-3.82GHz, the average in-band gain is 5.9dBi, the peak gain in the passband is 6.3dBi, the low-frequency out-band suppression level is higher than 35.3dB, the high-frequency out-band suppression level is higher than 40.3dB, and the maximum SAR value is 0.061W / kg, which is far lower than the international safety standard of 1.6W / kg.

[0061] Example 2

[0062] This embodiment provides a wireless communication device, including the broadband wearable filtering antenna with high out-of-band suppression level described in Embodiment 1.

[0063] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A broadband wearable filter antenna with high out-of-band suppression level, characterized by: The invention comprises a first dielectric substrate (1), a second dielectric substrate (2), a ground (3), a rectangular radiation patch (4), a longitudinal rectangular groove (5), an open annular groove (6), a transverse rectangular groove (7), a coaxial probe (8) and a T-shaped strip (9); the first dielectric substrate (1) is stacked on the second dielectric substrate (2); the rectangular radiation patch (4) is arranged on the upper surface of the first dielectric substrate (1); the open annular groove (6) is located below the middle of the rectangular radiation patch (4) and is used to generate a low-frequency radiation zero point and a new resonance point and widen the matching bandwidth; the transverse rectangular groove (7) is located below the middle of the rectangular radiation patch (4) and is used to generate a low-frequency radiation zero point and a new resonance point and widen the matching bandwidth; The rectangular groove (7) is located inside the open annular groove (6) and is used to change the current distribution outside the high-frequency band. The longitudinal rectangular groove (5) is located on the left and right sides of the open annular groove (6) and close to the left and right sides of the rectangular radiation patch (4) and is used to move the TM20 mode resonance point close to the passband. The T-shaped strip (9) is arranged on the upper surface of the second dielectric substrate (2) and is used to generate a high-frequency radiation zero point and widen the matching bandwidth. The ground (3) is arranged on the lower surface of the second dielectric substrate (2). The rectangular radiation patch (4) and the T-shaped strip (9) are connected through a coaxial probe (8).

2. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The length of the open annular groove (6) is half the wavelength corresponding to the low-frequency radiation zero-point frequency, and the left-right movement of the low-frequency radiation zero-point can be controlled by controlling the length of the open annular groove (6).

3. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The longitudinal length of the T-shaped strip (9) plus half of its transverse length is a quarter wavelength corresponding to the high-frequency radiation zero-point frequency. By controlling the length of the T-shaped strip (9), the left-right movement of the high-frequency radiation zero-point can be controlled.

4. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The ground (3), rectangular radiation patch (4), open annular groove (6), transverse rectangular groove (7), and T-shaped strip (9) are in a bilaterally symmetrical structure about the center line of the dielectric substrate.

5. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The longitudinal rectangular grooves (5) on the left and right sides of the open annular groove (6) are bilaterally symmetrical with respect to the center line of the dielectric substrate.

6. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The opening of the open annular groove (6) faces the upper edge of the rectangular radiation patch (4).

7. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The rectangular radiation patch (4) is located in the middle of the upper surface of the first dielectric substrate (1).

8. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The dielectric used in the first dielectric substrate (1) and the second dielectric substrate (2) is flexible and bendable polydimethylsiloxane, with a dielectric constant of 2.7 and a loss tangent of 0.013; the material of the ground (3), the rectangular radiation patch (4) and the T-shaped strip (9) are all conductive nylon fabric with a surface resistivity of less than 0.009Ω / m 2 .

9. The broadband wearable filtering antenna with high out-of-band suppression level according to claim 1, characterized in that The first dielectric substrate (1) and the second dielectric substrate (2) are of equal size and are both cubes, and the ground (3) covers the entire lower surface of the second dielectric substrate (2).

10. A wireless communication device, characterized in that A broadband wearable filtering antenna with a high out-of-band suppression level comprising the antenna according to any one of claims 1 to 9.

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