An anti-interference high-order band-stop filter ultra-wideband antenna and an anti-interference method

Abstract

The present invention provides an anti-interference high-order band-stop filtering ultra-wideband antenna. It includes a dielectric substrate carrier, a printed monopole antenna board, a microstrip feeder conductor, a metal floor, and three types of open resonant ring structures on the antenna. The three types of resonant rings are a pair of circular ring-shaped complementary open resonant ring gaps etched on the printed monopole antenna board, two pairs of rectangular complementary open resonant ring gaps etched on the metal floor, and a pair of metal open resonant rings are placed on both sides of the microstrip feeder conductor. The ultra-wideband antenna with high-order band-stop filtering function provided by the present invention effectively improves the anti-interference performance between the ultra-wideband system and the WIFI system through the multi-level distribution of multiple types of resonant rings.

Description

Technical Field

[0001] The present invention relates to the field of antennas with a band-stop filtering function, and in particular to an antenna with an anti-interference band-stop filtering function used in an ultra-wideband system. Background Art

[0002] Ultra-wideband technology is a wireless carrier communication technology that uses a wide frequency band. It does not use the sinusoidal carrier in the traditional communication system, but uses nanosecond non-sinusoidal narrow pulses to transmit data, so it occupies a large spectrum range. In 2002, the US Communications Commission allocated a total of 7.5 GHz bands from 3.1 to 10.6 GHz for UWB, and also limited its radiation power to -41.3dBm. UWB technology has the advantages of low system complexity, low power spectrum density of transmitted signals, insensitivity to channel fading, low interception capability, high positioning accuracy, and strong penetration capability. It is especially suitable for positioning and ranging in dense multipath places such as indoors. Since 2019, due to the release of new products of ultra-wideband (UWB) technology including the iPhone 11 series by some well-known companies and institutions such as Apple and the Car Connectivity Consortium (CCC) and the development of digital key specifications, ultra-wideband technology and corresponding systems have further received widespread attention from the scientific and technological community and the media.

[0003] At the same time, with the rapid development of mobile communications and the Internet of Things, the use of frequency bands has become increasingly intensive. Since the ultra-wideband system occupies an extremely wide bandwidth, it has to share the spectrum with the existing narrowband system. The development and application of various other frequency band wireless systems have made the existing frequency band resources increasingly tight, and the contradiction between the growing functional requirements and the limited spectrum resources has become increasingly obvious. For example, the fourth generation (4G) and fifth generation (5G) mobile communication standards, Bluetooth, WiFi bands, etc. in different operators have overlapping working frequency bands with ultra-wideband communication systems. In order to reduce the mutual interference between the UWB system and these other systems and ensure the normal operation of each communication system, the next generation of UWB systems needs to adopt relevant anti-interference technologies. In order to suppress the potential interference between the ultra-wideband system and the narrowband system, it is usually necessary to introduce a band-stop filter in the ultra-wideband system, but this will undoubtedly increase the size, complexity and cost of the system. In recent years, another simple and effective method has been proposed, which uses an antenna with a band-stop filter function introduced in the ultra-wideband system. As a key component of the ultra-wideband system, the characteristics of the antenna will directly affect the transmission performance of the system. By introducing gaps or loading branches, the filtering function of the antenna can be realized, thereby demonstrating the characteristics of a band-stop filter.

[0004] The Chinese patent with the patent application number of 202011079087.8 and the patent name of "A Miniaturized Dual Notch Ultra-Wideband Antenna" proposes an ultra-wideband antenna with two notch characteristics. The antenna covers the frequency band of 3GHz10.6GHz, and two U-shaped slots of different lengths are opened on the radiation patch. The slot forms a stop band in the 3.0-4.3GHz and 7.0-7.8GHz frequency bands, but the anti-interference ability of this invention is only -5dB, which cannot effectively play a blocking role. The Chinese patent with the patent application number of 202111608640.7 and the patent name of "Plane Ultra-Wideband Dual Notch Antenna and Smart Wearable Device" also proposes an ultra-wideband antenna with dual notch characteristics. Two notch bands are formed in the WiMAX and WIFI bands by etching U-shaped and open circular grooves on the radiation unit and the floor respectively. However, the filtering performance is not good enough in this invention. The return loss value in the filtering frequency band is about -5dB, and the corresponding voltage standing wave ratio VSWR is about 3.5. The filter-loaded structure adopted by the above antenna has average filtering performance, which is not as good as expected and cannot effectively play an anti-interference role. Therefore, an ultra-wideband antenna with good filtering performance can reduce the mutual interference between the UWB system and other systems, while ensuring the normal operation of each communication system. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an ultra-wideband antenna with a center frequency of 5.5 GHz and good filtering function, which greatly improves the current band-stop performance and solves the problem of mutual interference between the ultra-wideband system and the WIFI communication system.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An anti-interference high-order band-stop filter ultra-wideband antenna comprises a dielectric substrate, wherein adjacent printed monopole antenna plates and microstrip feeder conductors are arranged on the front of the dielectric substrate, and a pair of metal open resonant rings are arranged on both sides of the microstrip feeder conductors; a metal floor is arranged on the back of the dielectric substrate, and the metal floor comprises complementary open resonant ring gaps.

[0008] As a further solution of the present invention, the printed monopole antenna board includes a pair of circular ring-shaped complementary open resonant ring gaps, which are located at the bottom of the printed monopole antenna board.

[0009] As a further solution of the present invention, the metal floor includes two pairs of rectangular complementary open resonant ring gaps.

[0010] As a further solution of the present invention, the open resonant ring is composed of two pairs of trapezoidal metal open resonant rings, and each pair of the two pairs of trapezoidal metal open resonant rings is composed of two parts. The first part is a trapezoidal metal branch opening inward, that is, a trapezoidal metal branch opening toward the microstrip feeder conductor strip, and the second part is a trapezoidal metal branch opening outward, that is, a trapezoidal metal branch opening toward both sides of the metal floor, wherein the ladder ring metal branch opening inward is placed inside the ladder ring metal branch opening outward.

[0011] As a further solution of the present invention, the pair of circular ring-shaped complementary open resonant ring gaps consists of two parts, the first part is a circular ring-shaped gap opening upward, and the second part is a circular ring-shaped gap opening downward, wherein the circular ring-shaped gap opening upward is placed inside the circular ring-shaped gap opening downward.

[0012] As a further solution of the present invention, the metal floor is an isosceles trapezoidal structure, and the two pairs of rectangular complementary open resonant ring gaps are symmetrical to the connecting line of the upper base midpoint and the lower base midpoint of the isosceles trapezoidal structure.

[0013] As a further solution of the present invention, each pair of rectangular complementary open resonant ring gaps consists of two parts, the first part is a rectangular gap opening inward, that is, opening toward the microstrip feeder conductor strip, and the second part is a rectangular gap opening outward, that is, opening toward both sides of the metal floor, wherein the rectangular annular gap opening inward is placed inside the rectangular annular gap opening outward.

[0014] As a further solution of the present invention, the microstrip feeder conductor strip widens from top to bottom to achieve impedance transformation; the dielectric constant of the dielectric substrate is 2-10.

[0015] As a further solution of the present invention, the printed monopole antenna board is a circular or elliptical conductor patch or a square or rectangular conductor patch with a rounded lower end, and the metal floor is a square, rectangular or trapezoidal conductor patch with a rounded upper end.

[0016] The present invention also discloses an anti-interference method for a high-order band-stop filtering ultra-wideband antenna, comprising the following steps: generating a first-order band-stop filter effect by loading a pair of metal printed open resonant rings, generating a second-order band-stop filter effect by etching a complementary open resonant ring gap, and generating a third-order band-stop filter effect by etching a pair of complementary open resonant ring gaps.

[0017] The present invention has the following beneficial effects:

[0018] The ultra-wideband antenna with high-order band-stop filtering function provided by the present invention effectively improves the anti-interference performance between the ultra-wideband system and the WIFI system through the multi-level distribution of multiple types of resonant structures.

[0019] In the present invention, the metal floor is arranged on the reverse side of the dielectric substrate, the metal floor is in an isosceles trapezoidal shape, the printed monopole antenna board is arranged on the front side of the dielectric substrate, the metal floor and the printed monopole antenna are arranged on the reverse side and the front side of the dielectric substrate respectively, thereby better realizing the ultra-wideband characteristics; the microstrip feed line conductive strip is arranged on the reverse side of the dielectric substrate, and the microstrip feed line is narrowed and widened from top to bottom, so as to realize the impedance matching of the bottom and top antenna radiation patches of the microstrip feed line.

[0020] In the present invention, a pair of circular ring-shaped complementary open resonant ring gaps at the bottom of the monopole antenna plate, two pairs of rectangular complementary open resonant ring gaps on the floor, and metal isosceles trapezoidal open resonant rings on the left and right sides of the microstrip feeder conductor strip respectively have the performance of band-stop filters. These three types of open resonant rings and complementary open resonant ring gaps are combined together, which is equivalent to cascading multiple types of filters, thereby achieving the effect of improving filtering performance.

[0021] The high-order band-stop filter antenna of the present invention has been shown to be able to work in the range of 3.1-10.6 GHz through performance testing, and can cover the entire ultra-wideband communication frequency band. In the entire WIFI frequency band corresponding to 5.15-5.825 GHz, it produces good band-stop filtering characteristics, reduces the mutual interference between the UWB system and WIFI, and ensures the normal operation of multiple communication systems.

[0022] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Demonstrated the communication frequency band where WIFI and UWB coexist;

[0024] Figure 2 A schematic structural diagram of a common ultra-wideband antenna provided by an embodiment of the present invention;

[0025] Figure 3a A schematic diagram of the front structure of an ultra-wideband antenna with a high-order band-stop filter function provided by an embodiment of the present invention;

[0026] Figure 3b A schematic diagram of the back structure of an ultra-wideband antenna with a high-order band-stop filter function provided by an embodiment of the present invention;

[0027] Figure 4 A return loss curve diagram of an ultra-wideband antenna with a high-order band-stop filter function provided by one embodiment of the present invention;

[0028] Figure 5 A schematic diagram of the E-plane radiation direction of an ultra-wideband antenna with a high-order band-stop filter function at a frequency of 3.5 GHz provided by an embodiment of the present invention;

[0029] Figure 6 A schematic diagram of the H-plane radiation direction of an ultra-wideband antenna with a high-order band-stop filter function at a frequency of 3.5 GHz provided by an embodiment of the present invention;

[0030] Figure 7 A schematic diagram of the E-plane radiation direction of an ultra-wideband antenna with a high-order band-stop filter function at a frequency of 6.5 GHz provided by an embodiment of the present invention;

[0031] Figure 8 A schematic diagram of the H-plane radiation direction of an ultra-wideband antenna with a high-order band-stop filter function at a frequency of 6.5 GHz provided by an embodiment of the present invention;

[0032] Fig. 9 A schematic diagram of the E-plane radiation direction of an ultra-wideband antenna with a high-order band-stop filter function at a frequency of 10 GHz provided by an embodiment of the present invention;

[0033] Fig.10 A schematic diagram of the H-plane radiation direction of an ultra-wideband antenna with a high-order band-stop filter function at a frequency of 10 GHz provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further explained below in conjunction with the accompanying drawings and related knowledge, and described clearly and completely. Obviously, the described application is only a part of the embodiments of the present invention, rather than all the embodiments.

[0035] Reference Figure 1 The communication frequency band in which WIFI and UWB coexist is shown. Since the two frequency bands overlap, mutual interference between the systems is inevitable. Based on the problems existing in the prior art, an embodiment of the present invention provides an ultra-wideband antenna with good filtering function. By improving the antenna structure and radiation characteristics, a high-order band-stop filtering characteristic with a center frequency of 5.5 GHz is achieved, the band-stop performance is greatly improved, and the mutual interference problem between the ultra-wideband system and the WIFI communication system is solved.

[0036] Reference Figure 2As shown, a schematic diagram of the structure of an ultra-wideband antenna without high-order filtering characteristics. The antenna includes a first metal printed monopole antenna board 111, a first dielectric substrate 112, a first microstrip feeder conductor 113 and a first metal floor 114. The first metal monopole antenna board 111 is elliptical and is arranged on the front of the first dielectric substrate 112. The antenna monopole board unit is configured to radiate in the ultra-wideband communication band. The first metal floor 114 is arranged on the back of the first dielectric substrate 112. The first metal floor 114 is a rounded isosceles trapezoid. The width of the first metal floor 114 is 0.2-0.5 times the longest working wavelength, and the height of the first metal floor 114 is 0.1-0.8 times the width of the first metal floor 114; the top width of the first metal floor 114 is 0.2-0.8 times the bottom width of the first metal floor 114, and the projection distance between the first printed single antenna board 111 and the first metal floor 114 is 0.02-0.1 times the height of the first metal floor. This implementation can effectively serve as a part of the antenna matching circuit, participate in the radiation of the antenna, and ensure that the antenna can cover the entire ultra-wideband frequency band of 3.1-10.6 GHz.

[0037] Reference Figure 3a and Figure 3b to Figure 10 As shown, the present invention provides an anti-interference high-order band-stop filter ultra-wideband antenna. It includes dielectric substrates 211 and 221, a printed monopole antenna board 212, a microstrip feeder conductor 215, a metal floor 222, and three types of open resonant ring structures on the antenna. Figure 2 A plurality of metal printed open resonant rings and complementary open resonant ring gaps are loaded on the antenna. The three types of resonant rings are a pair of circular ring-shaped complementary open resonant ring gaps etched on the printed monopole antenna board, two pairs of rectangular complementary open resonant ring gaps etched on the metal floor 222, and a pair of metal open resonant rings are placed on both sides of the microstrip feeder conductor. The ultra-wideband antenna with high-order band-stop filtering function provided by the present invention effectively improves the anti-interference performance between the ultra-wideband system and the WIFI system through the multi-level distribution of multiple types of resonant structures.

[0038] Reference Figure 3a and Figure 3b The front and back of the antenna are shown respectively. After the improvement, the printed monopole antenna board includes a pair of circular ring-shaped complementary open resonant ring slots 213, which are placed at the bottom of the monopole antenna board. After the improvement, the metal floor 222 includes two pairs of rectangular complementary open resonant ring slots 223. After the improvement, a pair of metal open resonant rings are placed on both sides of the microstrip feeder conductor. The open resonant ring is composed of two pairs of trapezoidal metal open resonant rings 214.

[0039] Reference Figure 4As shown, it is a return loss curve diagram of the ultra-wideband antenna without band-stop characteristics and the ultra-wideband antenna with high-order band-stop filtering function provided by the present invention, Figure 4 The vertical axis is return loss / dB, and the horizontal axis is frequency / GHz. Figure 4 It can be seen that Figure 2 An ultra-wideband antenna without high-order filtering characteristics provided by an embodiment of the present invention can operate in the entire 3.1-10.6 GHz ultra-wideband frequency band. Figure 4 It can also be seen that the ultra-wideband antenna with high-order band-stop filtering function in this embodiment produces a stopband characteristic at 5.13GHz-5.89GHz, and the extreme value of the return loss is greater than -1dB. The filtering performance is much better than the technology mentioned in the background technology. The effect of multiple resonant ring cascade is reflected.

[0040] Figure 5 , Figure 6 Schematic diagrams of the E-plane and H-plane radiation directions of an ultra-wideband antenna with a high-order band-stop filtering function provided by an embodiment of the present invention at a frequency of 3.5 GHz;

[0041] Figure 7 , Figure 8 Schematic diagrams of the E-plane and H-plane radiation directions of an ultra-wideband antenna with a high-order band-stop filtering function provided by an embodiment of the present invention at a frequency of 6.5 GHz;

[0042] Fig. 9 , Fig.10 The schematic diagrams of the E-plane and H-plane radiation directions of the ultra-wideband antenna with high-order band-stop filtering function at 10 GHz are provided in accordance with an embodiment of the present invention. From the radiation patterns at 3.5 GHz, 6.5 GHz and 10 GHz in the ultra-wideband frequency band, it can be seen that the ultra-wideband antenna with high-order band-stop filtering function has relatively consistent radiation characteristics over a very wide frequency band.

[0043] In the present invention, a dielectric substrate, a metal printed monopole antenna plate, a metal floor and a microstrip feeder conductor are included. The metal monopole antenna plate is elliptical and is arranged on the front of the dielectric substrate. The antenna monopole plate unit is configured to radiate in an ultra-wideband communication band. The antenna is loaded with multiple metal printed open resonant rings and complementary open resonant ring gaps. Among them, a pair of circular ring-shaped complementary open resonant ring gaps are etched on the printed monopole antenna plate and placed at the bottom of the monopole antenna plate. Two pairs of rectangular complementary open resonant ring gaps are etched on the metal floor. A pair of metal open resonant rings are respectively placed on both sides of the microstrip feeder conductor. The open resonant ring is composed of two pairs of trapezoidal metal open resonant rings.

[0044] In the present invention, the metal floor is arranged on the reverse side of the dielectric substrate, the metal floor is in an isosceles trapezoid, the printed monopole antenna board is arranged on the front side of the dielectric substrate, and the metal floor and the printed monopole antenna are arranged on the reverse side and the front side of the dielectric substrate respectively, thereby better realizing the ultra-wideband characteristics.

[0045] Further preferably, the microstrip feeder conductor strip is arranged on the reverse side of the dielectric substrate, and the microstrip feeder becomes wider from top to bottom, so as to achieve impedance matching between the bottom and top antenna radiation patches of the microstrip feeder.

[0046] Further preferably, the bottom edge of the metal floor is rounded to optimize impedance matching and relax the tolerance of antenna processing.

[0047] Further preferably, a pair of circular ring-shaped complementary open resonant ring gaps are provided at the bottom of the monopole antenna plate.

[0048] Further preferably, two pairs of rectangular complementary open resonant ring gaps on the metal floor and the metal isosceles trapezoidal open resonant rings on the left and right sides of the microstrip feeder conductor strip respectively have the performance of band-stop filters. These three types of open resonant rings and complementary open resonant ring gaps are combined together, which is equivalent to cascading multiple types of filters, thereby achieving the effect of improving the filtering performance.

[0049] The ultra-wideband antenna with high-order band-stop filtering function of the embodiment of the present invention has been tested and shown to be able to work in the 3.1-10.6GHz ultra-wideband frequency band, and to produce a stopband characteristic in the 5.13GHz-5.89GHz range, and the extreme value of the return loss is greater than -1dB, and the effect of multiple resonant ring cascades is reflected. The anti-interference performance between the ultra-wideband system and the WIFI system is greatly improved.

[0050] The following provides specific implementation methods:

[0051] Example 1

[0052] An anti-interference high-order band-stop filter ultra-wideband antenna, comprising a dielectric substrate 211, a printed monopole antenna board 212, a microstrip feeder conductor 215, a metal floor 222, and a loaded metal printed split resonant ring (SRR) 214 and an etched complementary split resonant ring gap (CSRR);

[0053] The upper surface of the dielectric substrate 211 carrier includes a printed monopole antenna plate 212, a microstrip feeder conductor 215, a pair of loaded metal printed split resonant rings (SRR) 214 and an etched complementary split resonant ring slot (CSRR) 213, and the lower surface of the dielectric substrate includes a metal floor 222 and a pair of complementary split resonant ring slots (CSRR) 223 etched on the metal floor;

[0054] In the present invention, the antenna unit is configured to radiate in the ultra-wideband communication frequency band, a pair of loaded metal printed open resonant rings 214 are respectively placed on both sides of the microstrip feeder conductor 215, an etched complementary open resonant ring slot 213 is placed at the bottom of the monopole antenna plate, and a pair of etched complementary open resonant ring slots 223 are placed on the metal floor;

[0055] In the present invention, a pair of loaded metal printed open resonant rings 214 are configured to produce a band-stop filter effect for the first time on the WIFI frequency band, an etched complementary open resonant ring slot 213 is configured to produce a band-stop filter effect for the second time on the WIFI frequency band, and a pair of etched complementary open resonant ring slots 223 are configured to produce a band-stop filter effect for the third time on the WIFI frequency band;

[0056] In a preferred embodiment of the present invention, the printed monopole antenna board 212 is a circular or elliptical conductor patch or a square or rectangular conductor patch with a rounded lower end. The metal floor 222 is a square, rectangular or trapezoidal conductor patch with a rounded upper end. Further preferably, the metal floor 222 is arranged on the reverse side of the dielectric substrate, the metal floor is a rounded isosceles trapezoid, the width of the metal floor is 0.2-0.5 times the longest working wavelength, and the height of the metal floor is 0.1-0.8 times the width of the metal floor;

[0057] More preferably, the top width of the metal floor 222 is 0.2-0.8 times the bottom width of the metal floor, and the projection distance between the printed single antenna board and the metal floor is 0.02-0.1 times the height of the metal floor.

[0058] Reference Figure 3a As shown, the microstrip feeder strip 215 is arranged on the front side of the dielectric substrate 211, and the microstrip feeder strip 215 is narrowed and widened from top to bottom to achieve impedance transformation. Optionally, the first end of the microstrip feeder strip 215 is electrically connected to the printed monopole antenna board, and the second end of the microstrip feeder strip 215 is electrically connected to the signal transmission structure of the system.

[0059] In a preferred embodiment of the present invention, the dielectric constant of the dielectric substrate 211 is 2-10, the loss tangent is less than or equal to 0.001, and the thickness is less than or equal to 3 mm.

[0060] In a preferred embodiment of the present invention, each open resonant ring (SRR) 214 includes two groups of open metal conduction strips of the same shape and different sizes, one of which is placed inside the other, and the openings of the two groups are opposite to each other. Each complementary open resonant ring (CSRR) slot 213 includes two groups of open slots of the same shape and different sizes on a metal plate, one of which is placed inside the other, and the openings of the two groups are opposite to each other.

[0061] In a preferred embodiment of the present invention, the width of each group of open metal bands in each open resonant ring is 0.1-1 mm, and the spacing between the metal bands is 0.5-2 times the width of the metal bands. The width of each group of open gaps in each complementary open resonant ring is 0.1-1 mm, and the spacing between the gaps is 0.5-2 times the gap width. The upper and lower spacing of each resonant ring is more than twice the gap width of the complementary open resonant ring or the width of the metal band of the open resonant ring.

[0062] The printed monopole antenna board in the present invention includes an elliptical antenna radiation body, a pair of circular ring-shaped complementary open resonant ring gaps, a metal floor as part of the antenna impedance matching structure to participate in radiation, the metal floor includes two pairs of rectangular complementary open resonant ring gaps, the loaded metal printed open resonant ring includes two pairs of trapezoidal metal open resonant rings, and a pair of metal open resonant rings are respectively placed on both sides of the microstrip feeder conductor. Among them, the antenna unit is an elliptical conductor patch, which has a simple structure, is easy to implement in terms of process, and is easy to integrate with the circuit.

[0063] In the present invention, the metal floor 222 is arranged on the reverse side of the dielectric substrate 211, the metal floor 222 is an isosceles trapezoid, the printed monopole antenna board is arranged on the front side of the dielectric substrate, and the metal floor and the printed monopole antenna are respectively arranged on the reverse side and the front side of the dielectric substrate, thereby better realizing the ultra-wideband characteristics.

[0064] In the present invention, the microstrip feeder conductor strip is arranged on the reverse side of the dielectric substrate, and the microstrip feeder becomes wider from top to bottom to achieve impedance matching between the bottom and top antenna radiation patches of the microstrip feeder.

[0065] The high-order band-stop filter antenna of the embodiment of the present invention has been shown to be able to operate at 3.1-10.6 GHz through performance testing, and can cover the entire ultra-wideband communication frequency band. In the entire WIFI frequency band corresponding to 5.15-5.825 GHz, it produces good band-stop filtering characteristics, reduces the mutual interference between the UWB system and WIFI, and ensures the normal operation of multiple communication systems.

[0066] Example 2

[0067] An anti-interference high-order band-stop filter ultra-wideband antenna comprises a dielectric substrate 211, a printed monopole antenna plate 212, a microstrip feeder conductor 215, a metal floor 222, a loaded metal printed split resonant ring (SRR) 214 and an etched complementary split resonant ring slot (CSRR); a pair of loaded metal printed split resonant rings 214 are configured to produce a band-stop filter effect for the first time in the WIFI frequency band, an etched complementary split resonant ring slot 213 is configured to produce a band-stop filter effect for the second time in the WIFI frequency band, and a pair of etched complementary split resonant ring slots 223 are configured to produce a band-stop filter effect for the third time in the WIFI frequency band. The resonant ring is equivalent to a plurality of band-stop filters cascaded, thereby achieving the effect of a high-order band-stop filter, and improving the anti-interference capability between the ultra-wideband system and the WIFI system.

[0068] In a preferred embodiment, when the antenna operates in an ultra-wideband frequency band, the current distribution is not uniform. When the metal monopole antenna 212 radiates, the current is more concentrated on the lower side of the monopole. In order to achieve a better anti-interference effect, a pair of circular ring-shaped complementary open resonant ring gaps 213 are placed at the bottom of the monopole antenna plate 212. A pair of circular ring-shaped complementary open resonant ring gaps 213 are composed of two parts, the first part is a circular ring gap opening upward, and the second part is a circular ring gap opening downward. The circular ring gap opening upward is placed inside the circular ring gap opening downward. This pair of circular ring-shaped complementary open resonant ring gaps 213 is symmetrical with the minor axis of the ellipse as the midline to reduce the increase in cross-polarization of the antenna caused by current asymmetry.

[0069] In a preferred embodiment, when the antenna works in the ultra-wideband frequency band, the metal floor 222, as part of the matching circuit, also participates in the radiation. This means that current is also gathered on the metal floor 222. In order to enhance the anti-interference effect, the complementary open resonant ring gap is used to be configured on the metal floor 222. In order to ensure the symmetry of the current flowing through the floor, the resonant ring should also be symmetrical with the connection line of the upper bottom midpoint and the lower bottom midpoint of the isosceles trapezoidal floor 222 after smoothing. A pair of complementary open resonant ring gaps can be placed symmetrically with the connection line as the center line. On the other hand, since the microstrip feeder conductor 215 also takes the connection line as the center line, the current will flow above the center line. A pair of complementary open resonant ring gaps placed below the microstrip feeder conductor 215 will cause too much impact on the current flowing through, resulting in too wide a resistance band width, causing unnecessary waste of communication frequency band resources. To solve this problem, two pairs of complementary open resonant ring gaps 223 are placed on the left and right sides of the connection line between the upper bottom midpoint and the lower bottom midpoint of the trapezoidal floor 222. Two pairs of rectangular complementary open resonant ring gaps 223 assume this function. Each pair of rectangular complementary open resonant ring gaps 223 consists of two parts, the first part is a rectangular gap that opens inward, that is, toward the microstrip feeder line guide strip 215, and the second part is a rectangular gap that opens outward, that is, toward both sides of the floor. The rectangular annular gap that opens inward is placed inside the rectangular annular gap that opens outward. The two pairs of rectangular complementary open resonant ring gaps 223 are symmetrical on the left and right sides of the connecting line of the upper bottom midpoint and the lower bottom midpoint of the trapezoidal floor 222 to reduce the cross polarization of the antenna caused by the current asymmetry. In addition, the placement position has a small overlap with the projection of the microstrip feeder line 215 onto the floor 222, which not only ensures the stability of the current flowing through, but also can achieve the effect of the band-stop function.

[0070] In some embodiments, when the antenna operates in an ultra-wideband frequency band, the current flowing through the metal feed conductive strip 215 will generate an electric field on both sides of the conductive strip. Placing a metal open resonant ring can also play the role of a band-stop filter. And the closer to the metal conductive strip 215, the greater the electric field strength. In order to achieve a better anti-interference effect, two pairs of trapezoidal metal open resonant rings 214 are placed on both sides of the feed conductive strip 215. The trapezoidal bottom side of the trapezoidal metal open resonant ring 214 is longer than the upper side, which can produce more coupling effects with the metal feed conductive strip 215.

[0071] Further preferably, two pairs of trapezoidal metal open resonant rings 214 are placed on the left and right sides of the feeder conductor 215. Each pair of trapezoidal ring-shaped open resonant rings 214 consists of two parts, the first part is a trapezoidal metal branch opening inward, that is, toward the microstrip feeder conductor, and the second part is a trapezoidal metal branch opening outward, that is, toward both sides of the floor. The inward-opening ladder ring metal branch is placed inside the outward-opening ladder ring metal branch. The two pairs of trapezoidal open resonant rings 214 are placed on the left and right sides of the feeder conductor 215, which can also reduce the cross-polarization of the antenna caused by current asymmetry.

[0072] Among them, the size of the loaded metal printed open resonant ring, the width of the metal conduction band and the size and width of the etched complementary open resonant ring gap will seriously affect the bandwidth and center frequency of the antenna. In addition, each individual open resonant ring and the complementary open resonant ring gap also produce mutual coupling when the antenna is working. Mutual coupling includes the mutual coupling of the rectangular complementary open resonant ring gap 223 and the circular complementary open resonant ring gap 213, the mutual coupling of the metal isosceles trapezoidal open resonant ring 214 and the rectangular complementary open resonant ring gap 223, and the mutual coupling of the metal isosceles trapezoidal open resonant ring 214 and the circular complementary open resonant ring gap 213. Excessive mutual coupling will cause the center frequency of the stop band to shift and affect the matching characteristics within the passband. In order to reduce the influence of mutual coupling, it is necessary to reasonably arrange the positions of each resonant ring and increase the physical distance between each resonant ring. In some embodiments, the physical distance between each resonant ring in the vertical direction is not less than 0.8mm.

[0073] In some embodiments, the microstrip feed line strip 215 is disposed on the front side of the dielectric substrates 211 and 221. The microstrip feed line strip 215 widens from top to bottom to achieve impedance transformation. The characteristic impedance of the input end of the microstrip feed line strip 215 is 50 ohms. The lower end of the microstrip feed line strip 215 is connected to the inner conductor of the coaxial connector.

[0074] In some embodiments, the dielectric substrates 211 and 221 have a dielectric constant of 2-10, a loss tangent of less than or equal to 10-3, and a thickness of less than or equal to 3 mm.

[0075] Reference Figure 4 As shown, it is a return loss curve diagram of the ultra-wideband antenna without band-stop characteristics and the ultra-wideband antenna with high-order band-stop filtering function provided by the present invention, Figure 4 The vertical axis is return loss / dB, and the horizontal axis is frequency / GHz. Figure 4 It can be seen that Figure 2 An ultra-wideband antenna without high-order filtering characteristics provided by an embodiment of the present invention can operate in the entire 3.1-10.6 GHz ultra-wideband frequency band. Figure 4 It can also be seen that the ultra-wideband antenna with high-order band-stop filtering function in this embodiment produces a stopband characteristic at 5.13GHz-5.89GHz, and the extreme value of the return loss is greater than -1dB. The filtering performance is much better than the technology mentioned in the background technology. The effect of multiple resonant ring cascade is reflected.

[0076] Figure 5 , Figure 6 Schematic diagrams of the E-plane and H-plane radiation directions of an ultra-wideband antenna with a high-order band-stop filtering function provided by an embodiment of the present invention at a frequency of 3.5 GHz; Figure 7 , Figure 8 Schematic diagrams of the E-plane and H-plane radiation directions of an ultra-wideband antenna with a high-order band-stop filtering function provided by an embodiment of the present invention at a frequency of 6.5 GHz; Fig. 9 , Fig.10 The schematic diagrams of the E-plane and H-plane radiation directions of the ultra-wideband antenna with high-order band-stop filtering function at 10 GHz are provided in accordance with an embodiment of the present invention. From the radiation patterns at 3.5 GHz, 6.5 GHz and 10 GHz in the ultra-wideband frequency band, it can be seen that the ultra-wideband antenna with high-order band-stop filtering function has relatively consistent radiation characteristics over a very wide frequency band.

[0077] The technical principle of the present invention is described above in combination with the specific embodiments, which are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments, and all technical solutions under the idea of ​​the present invention belong to the protection scope of the present invention. Those skilled in the art can think of other specific implementations of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. An anti-interference high-order band-stop filter ultra-wideband antenna, characterized in that: It comprises a dielectric substrate, wherein adjacent printed monopole antenna plates and microstrip feeder conductors are arranged on the front of the dielectric substrate, and a pair of metal open resonant rings are arranged on both sides of the microstrip feeder conductors; A metal floor is provided on the back of the dielectric substrate, and the metal floor includes complementary open resonant ring gaps. The printed monopole antenna board includes a pair of circular ring-shaped complementary open resonant ring gaps, which are located at the bottom of the printed monopole antenna board. The pair of circular ring-shaped complementary open resonant ring gaps are composed of two parts, the first part is a circular ring gap opening upward, and the second part is a circular ring gap opening downward, wherein the circular ring gap opening upward is placed inside the circular ring gap opening downward, and the open resonant ring is composed of two pairs of trapezoidal metal open resonant rings, and each pair of the two pairs of trapezoidal metal open resonant rings is composed of two The invention is composed of two parts, the first part is a trapezoidal metal branch opening inward, that is, a trapezoidal metal branch opening toward the microstrip feeder conductor, and the second part is a trapezoidal metal branch opening outward, that is, a trapezoidal metal branch opening toward both sides of the metal floor, wherein the ladder ring metal branch opening inward is placed inside the ladder ring metal branch opening outward, and the trapezoidal bottom side of the trapezoidal metal open resonant ring is closer to the metal feeder conductor than the upper side; the metal floor is an isosceles trapezoidal structure, and the gaps of the two pairs of rectangular complementary open resonant rings are symmetrical to the connecting lines of the upper bottom midpoint and the lower bottom midpoint of the isosceles trapezoidal structure, and the printed monopole antenna board is a circular or elliptical conductor patch or a square or rectangular conductor patch with a rounded lower end.

2. The anti-interference high-order band-stop filtering ultra-wideband antenna according to claim 1, characterized in that: The metal floor comprises two pairs of rectangular complementary open resonant ring slots.

3. The anti-interference high-order band-stop filtering ultra-wideband antenna according to claim 2, characterized in that: Each pair of rectangular complementary open resonant ring gaps consists of two parts. The first part is a rectangular gap opening inward, that is, opening toward the microstrip feeder conductor strip, and the second part is a rectangular gap opening outward, that is, opening toward both sides of the metal floor, wherein the rectangular annular gap opening inward is placed inside the rectangular annular gap opening outward.

4. The anti-interference high-order band-stop filtering ultra-wideband antenna according to claim 3, characterized in that: The microstrip feeder conductor strip widens from top to bottom to achieve impedance transformation; the dielectric constant of the dielectric substrate is 2-10.

5. An anti-interference method using the anti-interference high-order band-stop filter ultra-wideband antenna as claimed in claim 1, characterized in that: The following steps are involved: A first-order band-stop filter effect is generated by loading a pair of metal printed open resonant rings, a second-order band-stop filter effect is generated by etching a complementary open resonant ring gap, and a third-order band-stop filter effect is generated by etching a pair of complementary open resonant ring gaps. By combining the open resonant ring and the complementary open resonant ring gaps, the anti-interference filtering performance is effectively improved.

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