Wideband wearable filtering antenna with high out-of-band rejection level and wireless communication equipment

Abstract

The invention discloses a broadband wearable filter antenna with a high out-of-band rejection level and a wireless communication device, the antenna is composed of two layers of flexible dielectric substrates (a first dielectric substrate and a second dielectric substrate), a polydimethylsiloxane material is adopted, a rectangular radiation patch is loaded on the upper surface of the first dielectric substrate, a radiation zero point is introduced at a low frequency by loading an open annular groove, and the upper surface of the first dielectric substrate is provided with a first dielectric layer and a second dielectric layer; a high-frequency radiation zero point is introduced by loading the T-shaped strip on the upper surface of the second dielectric substrate, the high-frequency out-of-band rejection level is improved by loading the transverse rectangular groove and the longitudinal rectangular groove in the rectangular radiation patch, and the bandwidth is widened through loading of the open annular groove and the T-shaped strip. The antenna is integrally designed to be flexible, is suitable for wearable equipment, and still meets performance requirements after a human body tissue model is loaded. According to the invention, high out-of-band rejection level and broadband filtering performance are realized at the same time.

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 have an increasing demand for miniaturization, multifunctionality and high performance of communication devices. In order to meet these needs, filter antennas have been proposed as an emerging technology. However, existing filter antenna designs are mostly focused on rigid substrates, which are difficult to meet the requirements of wearable devices for flexibility, lightness and radiation safety. The introduction of wearable filter antennas is conducive to solving this problem. 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 a high out-of-band suppression level, which can have good broadband characteristics and stable gain while meeting the 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 solutions: a broadband wearable filtering antenna with a high out-of-band suppression level, comprising a first dielectric substrate, a second dielectric substrate, a ground, a rectangular radiation patch, a longitudinal rectangular groove, an open annular groove, a transverse rectangular groove, a coaxial probe and a T-shaped strip; the first dielectric substrate is stacked on the second dielectric substrate, the rectangular radiation patch is arranged on the upper surface of the first dielectric substrate, the open annular groove is located below the middle of the rectangular radiation patch, 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 is located inside the open annular groove, and is used to change the high-frequency out-of-band current distribution, the longitudinal rectangular groove is located on the left and right sides of the open annular groove, and is close to the left and right sides of the rectangular radiation patch, and is used to bring the TM20 mode resonance point close 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 zero point and widen the matching bandwidth, the ground is arranged on the lower surface of the second dielectric substrate, and the rectangular radiation patch and the T-shaped strip are connected through 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, and the left-right movement of the low-frequency radiation zero-point can be controlled by controlling the length of the open annular groove.

[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, and the left-right movement of the high-frequency radiation zero-point can be controlled by controlling the length of the T-shaped strip.

[0008] Preferably, the ground, the rectangular radiation patch, the open annular groove, the transverse rectangular groove, and the 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 symmetrical about the center line of the dielectric substrate.

[0010] Preferably, the opening of the open annular groove faces the upper side 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 ground, rectangular radiation patch and T-shaped strip are all made of 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 comprises the above-mentioned broadband wearable filtering antenna with 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 zero point and a new resonance point at low frequency by loading an open annular groove on a rectangular radiation patch, thereby achieving filtering performance at low frequency and broadening the bandwidth; by loading a T-shaped strip, a radiation zero point is introduced at high frequency and the bandwidth is further broadened; by loading longitudinal rectangular grooves on both sides of the open annular groove and loading transverse rectangular grooves inside the open annular groove, the high-frequency filtering performance can be effectively improved, and finally the performance of broadband and high out-of-band suppression level is achieved at the same time.

[0019] 2. The antenna of the present invention adopts a combination of loading open annular grooves, transverse rectangular grooves, longitudinal rectangular grooves on a rectangular radiation patch and loading T-shaped strips on a second dielectric substrate to achieve a broadband wearable filtering antenna with high out-of-band suppression level, wherein the impedance bandwidth is 22.42% (3.05-3.82GHz), the average gain in the passband is 5.9dBi, and the peak gain in the passband is 6.3dBi. At 2.3 and 4.78GHz of the gain curve, two radiation zero points with gains lower than -35.2 and -47.75dB are introduced, wherein the low-frequency out-of-band suppression level is higher than 35.3dB, and the high-frequency out-of-band suppression level is higher than 40.3dB. 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 a 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 FIG. 4 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 This is an efficiency curve diagram of a broadband wearable filtering antenna with a 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] Fig. 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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.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] Fig.17 A SAR value diagram of a three-layer human tissue model loaded with a broadband wearable filtering antenna with a high out-of-band suppression level according to an embodiment of the present invention. DETAILED DESCRIPTION

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

[0038] Example 1

[0039] At present, wearable antennas have the problems of large size, low integration and single function. The wearable antenna and filter are integrated into a wearable filter antenna. Under the premise of meeting the wearable requirements, the antenna has both radiation and filtering performance, which is conducive to the miniaturization and multi-function of the wearable antenna. Therefore, this embodiment provides a broadband wearable filter antenna with a 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 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 in the middle position of the upper surface of the first dielectric substrate 1, the open annular groove 6 is located in the middle and lower part of the rectangular radiation patch 4, and its opening faces the upper side of the rectangular radiation 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 radiation 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 radiation patch 4 and the T-shaped strip 9 are connected through the coaxial probe 8.

[0040] In this embodiment, an open annular groove 6 is loaded on the rectangular radiation patch 4 to generate a low-frequency radiation zero point and a new resonance point, thereby widening the matching bandwidth. The length of the open annular groove 6 is half a 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, by setting a T-shaped strip 9 on the upper surface of the second dielectric substrate 2, a radiation zero point is introduced at high frequency, 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 loading the longitudinal rectangular grooves 5 on the left and right sides of the open annular groove 6, the TM20 mode resonance point is brought close to the passband, thereby improving the high frequency out-of-band suppression level and enhancing the high frequency selectivity.

[0043] Furthermore, by loading the 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, the rectangular radiation patch 4, the open annular groove 6, the transverse rectangular groove 7, and the T-shaped strip 9 are in a bilaterally symmetrical structure 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 by 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 ground 3, the rectangular radiation patch 4 and the T-shaped strip 9 are all made of conductive nylon fabric with a surface resistivity 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 the figure, it 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, it can be seen that the antenna |S 11 |<-10dB bandwidth is 3.05-3.82GHz, 22.42%, applied to 3.5GHz WiMAX band (3.4-3.6GHz).

[0051] See also Figure 5 As shown in FIG. 1 , the gain simulation curve of the broadband wearable filter antenna with high out-of-band suppression level in the present embodiment is shown, the average gain in the band is 5.9 dBi, and the peak gain in the passband is 6.3 dBi. At 2.3 and 4.78 GHz of the gain curve, two radiation zero points with gains lower than -35.2 and -47.75 dB are introduced, where the low-frequency out-of-band suppression level is higher than 35.3 dB, and the high-frequency out-of-band suppression level is higher than 40.3 dB.

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

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

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

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

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

[0057] See also Fig.15 The figure is a schematic diagram of 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 radiation of the antenna to the human body meets the safety standards.

[0058] See also Fig.16 As shown in FIG. 1 , the S parameter diagram of the broadband wearable filter antenna with high out-of-band suppression level in this embodiment is loaded with a three-layer human tissue model. As can be seen from the figure, after loading three layers of human tissue, the bandwidth is narrowed to a certain extent, 3.13-3.85GHz, 20.63%. However, it can still cover the 3.5GHz WiMAX band, meeting the use requirements.

[0059] See also Fig.17 As shown in FIG. 1 , the SAR value diagram of the broadband wearable filter antenna with high out-of-band suppression level in this embodiment loaded with a three-layer human tissue model is shown. As can be seen from the figure, the maximum SAR value of the antenna is 0.061 W / kg, which is much lower than the international safety standard of 1.6 W / kg.

[0060] In summary, the present invention generates a new resonance point while introducing a radiation zero point at low frequency by loading an open annular groove on a rectangular radiation patch, and combines with the original resonance point of the rectangular radiation patch to broaden the bandwidth. 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 broadened 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, the loading of a three-layer human tissue model can be used to ensure 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 gain in the band is 5.9dBi, the peak gain in the passband is 6.3dBi, the low-frequency out-of-band suppression level is higher than 35.3dB, the high-frequency out-of-band suppression level is higher than 40.3dB, and the maximum SAR value is 0.061W / kg, which is much 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 equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A broadband wearable filter antenna with high out-of-band suppression level, characterized in that: 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 to broaden the matching bandwidth; the transverse rectangular groove (7) 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 to broaden 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 bring 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 of a 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), the rectangular radiation patch (4), the open annular groove (6), the transverse rectangular groove (7), and the T-shaped strip (9) are in a left-right symmetrical structure with respect to 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 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 fabrics, 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 described in any one of claims 1 to 9.

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