A tri-band independently reconfigurable ultra-wideband monopole antenna

Abstract

The application discloses a three-trap independent reconfigurable ultra-wideband monopole antenna, which comprises a feeding structure and an antenna radiation structure, three U-shaped slots are arranged at the antenna radiation structure, each U-shaped slot can make the antenna radiation structure realize a half-wavelength resonance structure, each U-shaped slot corresponds to a trap frequency, and each U-shaped slot can cause the inversion of a current flowing therethrough and corresponding to the trap frequency, so that the radiation generated by the current is offset and cannot be radiated through the antenna radiation structure; an adjustable capacitor is loaded at each U-shaped slot, the path length and reactance size of the current flowing through each U-shaped slot can be changed by adjusting the adjustable capacitor at each U-shaped slot, so that the trap frequency corresponding to each U-shaped slot is changed; the three-trap independent reconfigurable ultra-wideband monopole antenna has the advantages that the three trap frequencies can be flexibly switched, three interference frequency bands can be avoided by switching the three trap frequencies, the three trap frequencies are adjustable, the spectrum resource utilization rate can be improved, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to a monopole antenna, in particular to a triple-notch independent reconfigurable ultra-wideband monopole antenna. Background Art

[0002] With the increasing development of mobile communications, communication systems are placing increasing demands on bandwidth. Ultra-wideband monopole antennas, as resonant antennas, possess broadband characteristics and are suitable for use in the 3.1-10.6 GHz civilian ultra-wideband frequency band designated by the FCC (Federal Communications Commission). However, many common communication services also fall within this civilian ultra-wideband frequency band, such as the n79 band used by mobile 5G, C-band satellite services, and wireless local area network (WLAN) bands. To prevent electromagnetic interference from these services in this civilian ultra-wideband band, designing an ultra-wideband monopole antenna with a notch function has become a simple and effective approach.

[0003] In recent years, antenna engineers have begun etching resonant structures directly onto or around the radiating patch of an ultra-wideband monopole antenna, enabling the antenna to notch within the interference frequency band. For example, a dual-notch monopole antenna, by adding two simple slots to its radiating patch, creates a dual-notch frequency characteristic, capable of eliminating electromagnetic interference from signals in the corresponding frequency bands. However, the resonant structure of existing ultra-wideband monopole antennas with notch characteristics is typically fixed and cannot be changed once designed. This means that their notch frequency is fixed and, when in use, can only eliminate electromagnetic interference from wireless devices whose operating frequency band matches their notch frequency. With the rapid development of wireless communication technology, the variety and number of wireless devices will continue to increase, and the number of wireless devices operating in frequency bands that do not match the notch frequency of existing ultra-wideband monopole antennas with notch characteristics is also increasing. This means that existing ultra-wideband monopole antennas with notch characteristics are facing an increasing number of interference sources.

[0004] In order to solve the problems caused by interference sources in existing ultra-wideband monopole antennas with notched characteristics, operators have to frequently replace ultra-wideband monopole antennas with notched characteristics or add additional filtering equipment, which leads to increased maintenance costs and waste of spectrum resources. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a three-notch independent reconfigurable ultra-wideband monopole antenna with three notch frequencies that can be flexibly switched. By switching the three notch frequencies, three interference frequency bands can be avoided, and the three notch frequencies are all adjustable, thereby improving the utilization rate of spectrum resources and reducing maintenance costs.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: a three-notch independent reconfigurable ultra-wideband monopole antenna, including a feeding structure and an antenna radiating structure, wherein the feeding structure is used to feed a signal into the antenna radiating structure, and the antenna radiating structure is used to radiate the signal fed by the feeding structure into free space, and the antenna radiating structure is provided with three U-shaped slots, each of which can enable the antenna radiating structure to achieve a half-wavelength resonant structure, each U-shaped slot corresponds to a notch frequency, and each U-shaped slot will cause the current flowing through it and corresponding to its notch frequency to be reversed, so that the radiation generated by the current flowing through it and corresponding to its notch frequency is offset and cannot be radiated through the antenna radiating structure, and each U-shaped slot is loaded with an adjustable capacitor. By adjusting the adjustable capacitor at each U-shaped slot, the path length and reactance of the current flowing through each U-shaped slot can be changed, thereby changing the notch frequency corresponding to each U-shaped slot.

[0007] Furthermore, the antenna radiation structure is arranged on a dielectric substrate, and the dielectric substrate is formed by an isosceles trapezoidal plate and a rectangular plate being integrally formed and connected. The length direction of the rectangular plate is defined as the front-to-back direction, the width direction is defined as the left-to-right direction, and the thickness direction is defined as the up-down direction. The isosceles trapezoidal plate is located on the front side of the rectangular plate, and the cross-section of the isosceles trapezoid is an isosceles trapezoid. The upper base of the isosceles trapezoid is located in front of its lower base and is parallel to the front end face of the rectangular plate. The end face formed by the upper base of the cross-section of the isosceles trapezoid is its front end face, and the end face formed by the lower base is its rear end face. The end faces, the end faces formed by the two waists are respectively the left end face and the right end face, the rear end face of the isosceles trapezoidal plate completely coincides with the front end face of the rectangular plate; the antenna radiation structure includes two metal patches, which are respectively referred to as the first metal patch and the second metal patch, the shape and size of the first metal patch are exactly the same as the upper end face of the isosceles trapezoidal plate, the first metal patch is attached to the upper end face of the isosceles trapezoidal plate, and the upper end face of the isosceles trapezoidal plate is completely covered; the second metal patch is attached to the upper end face of the rectangular plate, and the second The metal patch is rectangular, and its length direction is along the left-right direction and its width direction is along the front-back direction. The length of the second metal patch is equal to the width of the rectangular plate, the width of the second metal patch is less than the length of the rectangular plate, and the front side of the second metal patch completely coincides with the lower bottom of the first metal patch; three U-shaped grooves are opened on the second metal patch, and the upper end surface of the rectangular plate is exposed at the three U-shaped grooves. The three U-shaped grooves are respectively called the first U-shaped groove, the second U-shaped groove and the third U-shaped groove. The notch of the first U-shaped groove and the groove of the third U-shaped groove are The openings of the second U-shaped groove are all set forward, the opening of the second U-shaped groove is set backward, and the second U-shaped groove is located in front of the first U-shaped groove and the third U-shaped groove; the plane that makes the rectangular plate left-right symmetrical is called the first symmetry plane; the first U-shaped groove is located on the left side of the first symmetry plane, and there is a distance between the two, and the third U-shaped groove is located on the right side of the first symmetry plane, and there is a distance between the two; the first U-shaped groove and the third U-shaped groove are left-right symmetrical about the first symmetry plane; the second U-shaped groove is left-right symmetrical about the first symmetry plane.

[0008] Furthermore, the first U-shaped groove includes three rectangular grooves and two fan-shaped grooves with central angles of 180 degrees. The three rectangular grooves are respectively called the first rectangular groove, the second rectangular groove and the third rectangular groove, and the two fan-shaped grooves are respectively called the first fan-shaped groove and the second fan-shaped groove. The length direction of the first rectangular groove is along the left-right direction, and the width direction is along the front-back direction. The left side of the first rectangular groove is parallel to the plane where the left end face of the rectangular plate is located, and there is a distance between the two. The right side of the first rectangular groove is parallel to the first symmetry plane, and there is a distance between the two. The rear side of the first rectangular groove is located in front of the rear side of the second metal patch, and there is a distance between the two. The plane that makes the first rectangular groove left-right symmetrical is called the second symmetry plane. The second rectangular groove and the third rectangular groove are respectively located in front of the first rectangular groove. The length directions of the second rectangular groove and the third rectangular groove are both along the front-to-back direction, and the width directions are both along the left-to-right direction. The second rectangular groove is located on the left side of the second symmetric plane, and the left side of the second rectangular groove is located on the same straight line as the left side of the first rectangular groove. The rear side of the second rectangular groove is connected to the front side of the first rectangular groove and is in a fitted state. There is a distance between the right side of the second rectangular groove and the second symmetric plane. The first fan-shaped groove is located on the front side of the second rectangular groove, and the chord of the first fan-shaped groove completely coincides with the front side of the second rectangular groove. The third rectangular groove and the second fan-shaped groove are both located on the right side of the second symmetric plane. The second rectangular groove and the third rectangular groove are left-right symmetrical about the second symmetric plane, and the first fan-shaped groove and the second fan-shaped groove are left-right symmetrical about the second symmetric plane.The second U-shaped groove includes three rectangular grooves and two fan-shaped grooves with central angles of 180 degrees. The three rectangular grooves are respectively called the fourth rectangular groove, the fifth rectangular groove and the sixth rectangular groove, and the two fan-shaped grooves are respectively called the third fan-shaped groove and the fourth fan-shaped groove. The length direction of the fourth rectangular groove is along the left-right direction, and the width direction is along the front-back direction. The fourth rectangular groove is bilaterally symmetrical about the first symmetry plane. The left side of the fourth rectangular groove is located on the left side of the second symmetry plane and on the right side of the straight line where the right side of the second rectangular groove is located. There are respectively A distance, the front side of the fourth rectangular groove is located on the rear side of the front side of the second metal patch, and there is a distance between the two, the fifth rectangular groove and the sixth rectangular groove are respectively located on the rear side of the fourth rectangular groove, the length directions of the fifth rectangular groove and the sixth rectangular groove are both along the front-to-back direction, and the width directions are both along the left-to-right direction, the left side of the fifth rectangular groove and the left side of the fourth rectangular groove are located in the same straight line, the front side of the fifth rectangular groove is connected to the rear side of the fourth rectangular groove and is in a fitted state, the third fan-shaped groove is located on the rear side of the fifth rectangular groove, and the chord of the third fan-shaped groove is aligned with the rear side of the fifth rectangular groove. The edges completely overlap, there is a distance between the third fan-shaped groove and the front side of the first rectangular groove, the sixth rectangular groove and the fourth fan-shaped groove are both located on the right side of the first symmetry plane, the fifth rectangular groove and the sixth rectangular groove are left-right symmetrical about the first symmetry plane, and the third fan-shaped groove and the fourth fan-shaped groove are left-right symmetrical about the first symmetry plane; the adjustable capacitor loaded at the first U-shaped groove is called the first adjustable capacitor, the first adjustable capacitor is arranged in the middle of the first rectangular groove, one end of the first adjustable capacitor is connected to a part of the second metal patch located on the front side of the first rectangular groove, and the first adjustable capacitor is connected to the The other end of the adjustable capacitor is connected to a portion of the second metal patch located on the rear side of the first rectangular slot. The adjustable capacitor loaded on the second U-shaped slot is referred to as the second adjustable capacitor. The second adjustable capacitor is disposed in the middle of the fourth rectangular slot. One end of the second adjustable capacitor is connected to a portion of the second metal patch located on the front side of the fourth rectangular slot, and the other end of the second adjustable capacitor is connected to a portion of the second metal patch located on the rear side of the fourth rectangular slot. The adjustable capacitor loaded on the third U-shaped slot is referred to as the third adjustable capacitor. The first and third adjustable capacitors are bilaterally symmetrical about the first symmetry plane.

[0009] Furthermore, the three-notch independent reconfigurable ultra-wideband monopole antenna also includes an electric boundary plate and a floor. The electric boundary plate is used to realize the binding of electromagnetic waves so that the electromagnetic waves are transmitted in the feeding structure. The electric boundary plate is realized by a rectangular metal patch. The length direction of the electric boundary plate is along the front-to-back direction, and the width direction is along the left-to-right direction. The electric boundary plate is attached to the upper end face of the rectangular plate and is located on the left side of the first symmetry plane. The rear side of the electric boundary plate is in the same plane as the rear end face of the rectangular plate. The left side of the electric boundary plate is in the same plane as the left end face of the rectangular plate. The front side of the electric boundary plate is located behind the rear side of the second metal patch, and there is a gap between the two. There is a distance between the right side of the electric boundary plate and the straight line where the right side of the fifth rectangular groove is located and the left side of the straight line where the left side of the third rectangular groove is located. There is a distance between the right side of the electric boundary plate and the straight line where the right side of the fifth rectangular groove is located, and there is a distance between the right side of the electric boundary plate and the straight line where the left side of the third rectangular groove is located. The floor is realized by a rectangular metal patch, the length direction of the floor is along the left-right direction, and the width direction is along the front-back direction. The floor is attached to the upper end surface of the rectangular plate; the floor is located on the right side of the first symmetry plane, and the electric boundary plate and the floor are left-right symmetrical about the first symmetry plane.

[0010] Furthermore, the feeding structure includes two metal patches, which are respectively referred to as the third metal patch and the fourth metal patch. The third metal patch and the fourth metal patch are both rectangular, and their length directions are along the front-to-back direction, and their width directions are along the left-to-right direction. The third metal patch is attached to the upper end surface of the rectangular plate and is located between the electrical boundary plate and the floor. The rear side of the third metal patch is located in the same plane as the rear end surface of the rectangular plate. There is a distance between the left side of the third metal patch and the right side of the electrical boundary plate. There is a distance between the right side of the third metal patch and the left side of the floor. The length of the third metal patch is smaller than the length of the electrical boundary plate. The fourth metal patch is attached to the upper end surface of the rectangular plate and is located on the front side of the third metal patch. The width of the fourth metal patch is smaller than the width of the third metal patch. The front side of the fourth metal patch is connected to the rear side of the second metal patch and is in a bonded state. The third metal patch is bilaterally symmetrical with respect to the first symmetry plane, and the fourth metal patch is bilaterally symmetrical with respect to the first symmetry plane.

[0011] Furthermore, the upper bottom length of the first metal patch is 4.8 mm, the lower bottom length is 13 mm, the height is 4 mm, and the thickness is 0.035 mm. The length of the second metal patch is 13 mm, the width is 6 mm, and the thickness is 0.035 mm. The length of the first rectangular groove is 5 mm, the width is 0.5 mm, and the distance between the left side of the first rectangular groove and the left side of the second metal patch is 1 mm. mm, the distance between the rear side of the first rectangular groove and the rear side of the second metal patch is 0.75 mm, the length of the second rectangular groove is 1.5 mm, the width is 0.5 mm, the radius of the first fan-shaped groove is 0.25 mm, the length of the fourth rectangular groove is 8 mm, the width is 0.5 mm, the distance between the left side of the fourth rectangular groove and the left side of the second metal patch is 2.5 mm, the distance between the rear side of the fourth rectangular groove and the rear side of the second metal patch is 5 mm, the length of the fifth rectangular groove is 1.5 mm, the width is 0.5 mm, the radius of the third fan-shaped groove is 0.25 mm, and the material of the dielectric substrate is FR-4 , the dielectric constant is 4.4, the length of the rectangular plate is 22mm, the width is 13mm, and the thickness is 0.8mm, the length of the floor is 8.7mm, the width is 5.65mm, and the thickness is 0.035mm, the length of the electrical boundary plate is 8.7mm, the width is 5.65mm, and the thickness is 0.035mm, and the materials of the floor and the electrical boundary plate are both metal copper; the length of the third metal patch is 5.98mm, the width is 1.35mm, and the thickness is 0.035mm, the length of the fourth metal patch is 4.02mm, the width is 1.17mm, and the thickness is 0.035mm; the materials of the third metal patch and the fourth metal patch are both metal copper.

[0012] Compared with the prior art, the advantage of the present invention lies in that three U-shaped slots are provided at the antenna radiation structure, each U-shaped slot can enable the antenna radiation structure to achieve a half-wavelength resonant structure, each U-shaped slot corresponds to a notch frequency, and each U-shaped slot will cause the current flowing through it and corresponding to its notch frequency to be reversed, so that the radiation generated by the current flowing through it and corresponding to its notch frequency is offset and cannot be radiated through the antenna radiation structure. Each U-shaped slot is loaded with an adjustable capacitor. By adjusting the adjustable capacitor at each U-shaped slot, the path length and reactance of the current flowing through each U-shaped slot can be changed, thereby changing the notch frequency corresponding to each U-shaped slot. Therefore, the present invention has three notch frequencies that can be flexibly switched. By switching the three notch frequencies, three interference frequency bands can be avoided, and the three notch frequencies are all adjustable, thereby improving the utilization rate of spectrum resources and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A top view of the triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention;

[0014] Figure 2 This is a schematic structural diagram of the first rectangular slot of the triple-notch independently reconfigurable ultra-wideband monopole antenna of the present invention;

[0015] Figure 3 This is a schematic structural diagram of the second rectangular slot of the triple-notch independently reconfigurable ultra-wideband monopole antenna of the present invention;

[0016] Figure 4 The triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention has a first adjustment capacitor with a capacitance of 0.5 pF, a second adjustment capacitor with a capacitance of 1 pF, and a third adjustment capacitor with a capacitance of 0.3 pF. parameter diagram;

[0017] Figure 5 Surface current diagram of the three-notch independent reconfigurable ultra-wideband monopole antenna of the present invention at the 3.79GHz notch point;

[0018] Figure 6 The triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is configured such that the capacitance of the second adjustment capacitor and the capacitance of the third adjustment capacitor are fixed and the capacitance of the first adjustment capacitor changes. Parameter variation diagram;

[0019] Figure 7 The triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is configured such that the capacitance of the first adjustment capacitor and the capacitance of the third adjustment capacitor are fixed and the capacitance of the second adjustment capacitor changes. Parameter variation diagram;

[0020] Figure 8 The triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is configured such that the capacitance of the first adjustment capacitor and the capacitance of the second adjustment capacitor are fixed, and the capacitance of the third adjustment capacitor is changed. Parameter variation diagram. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0022] Example 1: Figure 1As shown, a three-notch independent reconfigurable ultra-wideband monopole antenna includes a feeding structure and an antenna radiating structure. The feeding structure is used to feed a signal into the antenna radiating structure, and the antenna radiating structure is used to radiate the signal fed into it by the feeding structure into free space. Three U-shaped slots are provided at the antenna radiating structure, each of which can enable the antenna radiating structure to achieve a half-wavelength resonant structure. Each U-shaped slot corresponds to a notch frequency. Each U-shaped slot will cause the current flowing through it and corresponding to its notch frequency to be reversed, so that the radiation generated by the current flowing through it and corresponding to its notch frequency is offset and cannot be radiated out through the antenna radiating structure. Each U-shaped slot is loaded with an adjustable capacitor. By adjusting the adjustable capacitor at each U-shaped slot, the path length and reactance of the current flowing through each U-shaped slot can be changed, thereby changing the notch frequency corresponding to each U-shaped slot.

[0023] In this embodiment, the U-shaped slot can generate a notch characteristic, which actually introduces a half-wavelength resonant structure. By designing the size of the U-shaped slot according to the frequency to be filtered, the desired notch frequency can be achieved. By loading an adjustable capacitor at each U-shaped slot, the current needs to pass through the adjustable capacitor when moving around the U-shaped slot, so that the original current path is divided into two, which increases the length and reactance of the current path, resulting in a change in the notch frequency, thereby changing the notch frequency. The capacitance value of the adjustable capacitor will affect the current path and reactance in the U-shaped slot. By changing the capacitance value of the adjustable capacitor, the path length and reactance of the current flowing through each U-shaped slot can be changed. The three U-shaped slots are independent of each other, so the three notch frequencies can be adjusted independently.

[0024] Example 2: This example is basically the same as Example 1, except that: in this example, the antenna radiation structure is provided on a dielectric substrate, and the dielectric substrate is formed by an isosceles trapezoidal plate 1 and a rectangular parallelepiped plate 2 integrally formed and connected. The length direction of the rectangular parallelepiped plate 2 is defined as the front-to-back direction, the width direction is defined as the left-to-right direction, and the thickness direction is defined as the up-down direction. The isosceles trapezoidal plate 1 is located on the front side of the rectangular parallelepiped plate 2, and the cross section of the isosceles trapezoidal plate 1 is an isosceles trapezoid. The upper base of the isosceles trapezoid is located in front of its lower base and is parallel to the front end face of the rectangular parallelepiped plate 2. The cross section of the isosceles trapezoidal plate 1 is The end face formed by the upper base is its front end face, the end face formed by the lower base is its rear end face, the end faces formed by the two waists are its left end face and right end face respectively, and the rear end face of the isosceles trapezoidal plate 1 completely coincides with the front end face of the rectangular parallelepiped plate 2; the antenna radiation structure includes two metal patches, which are respectively referred to as the first metal patch 3 and the second metal patch 4. The shape and size of the first metal patch 3 are exactly the same as those of the upper end face of the isosceles trapezoidal plate 1. The first metal patch 3 is attached to the upper end face of the isosceles trapezoidal plate 1, completely covering the upper end face of the isosceles trapezoidal plate 1; the second metal patch 4 is attached to the upper end face of the isosceles trapezoidal plate 1. On the upper end surface of the rectangular plate 2, the second metal patch 4 is rectangular, and its length direction is along the left-right direction, and its width direction is along the front-back direction. The length of the second metal patch 4 is equal to the width of the rectangular plate 2, and the width of the second metal patch 4 is less than the length of the rectangular plate 2. The front side of the second metal patch 4 completely coincides with the lower bottom of the first metal patch 3; three U-shaped grooves are opened on the second metal patch 4, and the upper end surface of the rectangular plate 2 is exposed at the three U-shaped grooves. The three U-shaped grooves are respectively called the first U-shaped groove 5, the second U-shaped groove 6 and the third U-shaped groove 7. The first U-shaped groove The notches of the first and third U-shaped grooves 5 and 7 are both set forward, and the notches of the second U-shaped grooves 6 are set backward. The second U-shaped groove 6 is located in front of the first U-shaped groove 5 and the third U-shaped groove 7. The plane that makes the rectangular plate 2 bilaterally symmetrical is called the first symmetry plane 8. The first U-shaped groove 5 is located on the left side of the first symmetry plane 8, and there is a distance between the two. The third U-shaped groove 7 is located on the right side of the first symmetry plane 8, and there is a distance between the two. The first U-shaped groove 5 and the third U-shaped groove 7 are bilaterally symmetrical about the first symmetry plane 8; the second U-shaped groove 6 is bilaterally symmetrical about the first symmetry plane 8.

[0025] In this embodiment, the notch frequency achieved by the first U-shaped groove 5 is higher than the notch frequency achieved by the second U-shaped groove 6 , and is lower than the notch frequency achieved by the third U-shaped groove 7 .

[0026] In this embodiment, the rear end face of the second metal patch 4 in the antenna radiating structure is connected to the front end face of the fourth metal patch 22 in the feeding structure, ensuring that the feeding structure can effectively transmit electromagnetic waves to the antenna radiating structure. The antenna radiating structure is formed by integrally forming a first metal patch 3 in the form of an isosceles trapezoidal plate and a second metal patch 4 in the form of a rectangular parallelepiped plate. The antenna radiating structure has an irregular shape, which helps to scatter and radiate signals, thereby improving the radiation gain of the antenna. The antenna radiating structure uses three U-shaped slots to increase the radiation area, which can promote broadband performance. When the feeding structure feeds electromagnetic waves into the antenna radiating structure, surface currents are generated on the surface of the antenna radiating structure. The overall current direction is in the front-to-back direction, but the current direction changes near the three U-shaped slots. At the preset notch frequency, the first U-shaped slot 5 causes the current to reverse at its slot mouth, resulting in the currents near the first U-shaped slot 5 canceling each other, so that the radiation at the notch frequency is canceled, generating a notch, and suppressing the radiation of the signal at the notch frequency. At the preset notch frequency, the second U-shaped slot 6 causes the current at its notch to reverse, causing the currents near the second U-shaped slot 6 to cancel each other out, canceling out the radiation at the notch frequency, creating a notch, and suppressing the radiation of the signal at the notch frequency. At the preset notch frequency, the third U-shaped slot 7 causes the current at its notch to reverse, causing the currents near the third U-shaped slot 7 to cancel each other out, canceling out the radiation at the notch frequency, creating a notch, and suppressing the radiation of the signal at the notch frequency.

[0027] Example 3: This example is basically the same as Example 2, except that: Figure 2 and Figure 3As shown, in this embodiment, the first U-shaped groove 5 includes three rectangular grooves and two fan-shaped grooves with a central angle of 180 degrees. The three rectangular grooves are respectively referred to as the first rectangular groove 9, the second rectangular groove 10 and the third rectangular groove 11, and the two fan-shaped grooves are respectively referred to as the first fan-shaped groove 12 and the second fan-shaped groove 13. The length direction of the first rectangular groove 9 is along the left-right direction, and the width direction is along the front-back direction. The left side of the first rectangular groove 9 is parallel to the plane where the left end face of the rectangular plate 2 is located, and there is a distance between the two. The right side of the first rectangular groove 9 is parallel to the first symmetry plane 8, and there is a distance between the two. The rear side of the first rectangular groove 9 is located in front of the rear side of the second metal patch 4, and there is a distance between the two. The plane that makes the first rectangular groove 9 bilaterally symmetrical is called the second symmetry plane, and the second rectangular groove 10 and the third rectangular groove 11 are respectively located in the first and second symmetry planes. On the front side of a rectangular groove 9, the length directions of the second rectangular groove 10 and the third rectangular groove 11 are both along the front-to-back direction, and the width directions are both along the left-to-right direction. The second rectangular groove 10 is located on the left side of the second symmetry plane, and the left side of the second rectangular groove 10 is on the same straight line as the left side of the first rectangular groove 9. The rear side of the second rectangular groove 10 is connected to the front side of the first rectangular groove 9 and is in a fitted state. There is a distance between the right side of the second rectangular groove 10 and the second symmetry plane. The first fan-shaped groove 12 is located on the front side of the second rectangular groove 10, and the chord of the first fan-shaped groove 12 completely coincides with the front side of the second rectangular groove 10. The third rectangular groove 11 and the second fan-shaped groove 13 are both located on the right side of the second symmetry plane. The second rectangular groove 10 and the third rectangular groove 11 are left-right symmetrical about the second symmetry plane, and the first fan-shaped groove 12 and the second fan-shaped groove 13 are left-right symmetrical about the second symmetry plane.The second U-shaped groove 6 includes three rectangular grooves and two fan-shaped grooves with central angles of 180 degrees. The three rectangular grooves are respectively referred to as the fourth rectangular groove 14, the fifth rectangular groove 15 and the sixth rectangular groove 16, and the two fan-shaped grooves are respectively referred to as the third fan-shaped groove 17 and the fourth fan-shaped groove 18. The length direction of the fourth rectangular groove 14 is along the left-right direction, and the width direction is along the front-back direction. The fourth rectangular groove 14 is bilaterally symmetrical about the first symmetry plane 8. The left side of the fourth rectangular groove 14 is located on the left side of the second symmetry plane and on the right side of the straight line where the right side of the second rectangular groove 10 is located. The left side of the fourth rectangular groove 14 is located between the second symmetry plane and the right side of the second rectangular groove 10. There is a distance between the straight lines where the edges are located, the front side of the fourth rectangular groove 14 is located behind the front side of the second metal patch 4, and there is a distance between the two, the fifth rectangular groove 15 and the sixth rectangular groove 16 are respectively located on the back side of the fourth rectangular groove 14, the length directions of the fifth rectangular groove 15 and the sixth rectangular groove 16 are both along the front-to-back direction, and the width directions are both along the left-to-right direction. The left side of the fifth rectangular groove 15 and the left side of the fourth rectangular groove 14 are located in the same straight line, the front side of the fifth rectangular groove 15 is connected to the back side of the fourth rectangular groove 14 and is in a fitted state, the third fan-shaped groove 17 is located on the back side of the fifth rectangular groove 15, and the third fan-shaped groove 17 The chord completely coincides with the rear side of the fifth rectangular slot 15, there is a distance between the third fan-shaped slot 17 and the front side of the first rectangular slot 9, the sixth rectangular slot 16 and the fourth fan-shaped slot 18 are both located on the right side of the first symmetry plane, the fifth rectangular slot 15 and the sixth rectangular slot 16 are left-right symmetrical about the first symmetry plane, the third fan-shaped slot 17 and the fourth fan-shaped slot 18 are left-right symmetrical about the first symmetry plane; the adjustable capacitor loaded at the first U-shaped slot 5 is called the first adjustable capacitor C1, the first adjustable capacitor C1 is arranged in the middle of the first rectangular slot 9, one end of the first adjustable capacitor C1 is connected to a part of the second metal patch 4 located on the front side of the first rectangular slot 9, and the first adjustable capacitor C1 is connected to the second metal patch 4. The other end of the adjustable capacitor C1 is connected to the portion of the second metal patch 4 located on the rear side of the first rectangular slot 9. The adjustable capacitor loaded on the second U-shaped slot 6 is referred to as the second adjustable capacitor C2. The second adjustable capacitor C2 is arranged in the middle of the fourth rectangular slot 14. One end of the second adjustable capacitor C2 is connected to the portion of the second metal patch 4 located on the front side of the fourth rectangular slot 14, and the other end of the second adjustable capacitor C2 is connected to the portion of the second metal patch 4 located on the rear side of the fourth rectangular slot 14. The adjustable capacitor loaded on the third U-shaped slot 7 is referred to as the third adjustable capacitor C3. The first adjustable capacitor C1 and the third adjustable capacitor C3 are bilaterally symmetrical about the first symmetry plane 8.

[0028] In this embodiment, the length of the first U-shaped slot 5 is calculated as the sum of twice the length of the first rectangular slot 9, twice the length of the second rectangular slot 10, twice the length of the third rectangular slot 11, the arc length of the first fan-shaped slot 12, and the arc length of the second fan-shaped slot 13. The length of the first U-shaped slot 5 is designed to be approximately half the wavelength of the signal at its notch frequency. The length of the second U-shaped slot 6 is calculated as the sum of twice the length of the fourth rectangular slot 14, twice the length of the fifth rectangular slot 15, twice the length of the sixth rectangular slot 16, and the arc length of the third fan-shaped slot 17 and the arc length of the fourth fan-shaped slot 18. The length of the second U-shaped slot 6 is designed to be approximately half the wavelength of the signal at its notch frequency. The length of the third U-shaped slot 7 is equal to the length of the first U-shaped slot 5 and is approximately half the wavelength of the signal at its notch frequency. At the preset notch frequency of the U-shaped slot, the phase relationship between the current and the electric field changes, causing the current in the U-shaped slot to reverse. This reversal causes some of the current in the U-shaped slot to cancel each other, forming a notch. The three adjustable capacitors force current to pass through the three U-shaped slots as it moves around them, splitting the original current path in two. This increases the length and reactance of the current path, resulting in a change in the notch frequency. The capacitance of each adjustable capacitor affects the current path and reactance within the U-shaped slot in which it resides, thereby changing the notch frequency within that slot, achieving adjustable notch frequency. According to the principle of half-wave resonant structure, the longer the designed length of the U-shaped slot, the lower the notch frequency. The second U-shaped slot 6 is designed to be longer, resulting in a lower notch frequency than the first and third U-shaped slots 5 and 7. The first U-shaped slot 5 is designed to be shorter, resulting in a higher notch frequency than the second U-shaped slot 6. The third U-shaped slot 7 is designed to be the same length as the first U-shaped slot 5. By adjusting the adjustable capacitor within it, its preset notch frequency can be increased compared to the first U-shaped slot 5. The first and third U-shaped slots 5 and 7 are bilaterally symmetrical about the first symmetry plane 8; the second U-shaped slot 6 is bilaterally symmetrical about the first symmetry plane 8. The second U-shaped slot 6 is positioned midway between the first and third U-shaped slots 5 and 7 to optimize their interaction and avoid interference. Maintaining the symmetry of the three U-shaped slots within the entire triple-notch independently reconfigurable ultra-wideband monopole antenna improves its directivity and gain. The even distribution of the three U-shaped slots achieves a smoother frequency response.

[0029] Embodiment 4: This embodiment is basically the same as embodiment 3, with the difference that: in this embodiment, a three-notch independent reconfigurable ultra-wideband monopole antenna also includes an electric boundary plate 19 and a floor 20. The electric boundary plate 19 is used to bind electromagnetic waves so that the electromagnetic waves are transmitted in the feeding structure. The electric boundary plate 19 is implemented by a rectangular metal patch. The length direction of the electric boundary plate 19 is along the front-to-back direction, and the width direction is along the left-to-right direction. The electric boundary plate 19 is attached to the upper end face of the rectangular plate 2 and is located on the left side of the first symmetry plane 8. The rear side of the electric boundary plate 19 is in the same plane as the rear end face of the rectangular plate 2, the left side of the electric boundary plate 19 is in the same plane as the left end face of the rectangular plate 2, and the front side of the electric boundary plate 19 is located on the second metal patch. The rear side of the rear side of the sheet 4 is located, and there is a distance between the two. The right side of the electrical boundary plate 19 is located to the right of the straight line where the right side of the fifth rectangular groove 15 is located and to the left of the straight line where the left side of the third rectangular groove 11 is located. There is a distance between the right side of the electrical boundary plate 19 and the straight line where the right side of the fifth rectangular groove 15 is located, and there is a distance between the right side of the electrical boundary plate 19 and the straight line where the left side of the third rectangular groove 11 is located; the floor 20 is realized by a rectangular metal patch, the length direction of the floor 20 is along the left-right direction, and the width direction is along the front-back direction. The floor 20 is attached to the upper end surface of the rectangular plate 2; the floor 20 is located on the right side of the first symmetry plane 8, and the electrical boundary plate 19 and the floor 20 are symmetrical about the first symmetry plane 8.

[0030] In this embodiment, the electrical boundary plate and floor are made of metallic conductors. The electric field of the electromagnetic wave is perpendicular to the floor 20, and the current is also perpendicular to the electric field and parallel to the floor 20. The electrical boundary plate and floor confine the incoming electromagnetic wave within the feed structure, preventing it from radiating outward and consuming energy, thereby improving antenna performance.

[0031] Embodiment 5: This embodiment is basically the same as the embodiment 4, except that: in this embodiment, the feeding structure includes two metal patches, which are respectively referred to as the third metal patch 21 and the fourth metal patch 22. The third metal patch 21 and the fourth metal patch 22 are both rectangular, and their length directions are along the front-to-back direction, and their width directions are along the left-to-right direction. The third metal patch 21 is attached to the upper end surface of the rectangular plate 2 and is located between the electrical boundary plate 19 and the floor 20. The rear side of the third metal patch 21 is in the same plane as the rear end surface of the rectangular plate 2, and the left side of the third metal patch 21 is aligned with the electrical boundary plate 19. 9, there is a distance between the right side edge of the third metal patch 21 and the left side edge of the floor 20, the length of the third metal patch 21 is less than the length of the electrical boundary plate 19, the fourth metal patch 22 is attached to the upper end surface of the rectangular plate 2 and is located on the front side of the third metal patch 21, the width of the fourth metal patch 22 is less than the width of the third metal patch 21, the front side edge of the fourth metal patch 22 is connected to the rear side edge of the second metal patch 4 and is in a fitted state, the third metal patch 21 is left-right symmetrical about the first symmetry plane 8, and the fourth metal patch 22 is left-right symmetrical about the first symmetry plane 8.

[0032] In this embodiment, the feeding structure adopts CPW feeding, feeding from bottom to top, and the input impedance of the feeding structure matches the 50𝛺 coaxial line.

[0033] In this embodiment, the feeding structure can transmit signals and feed the signals into the antenna radiation structure from bottom to top. The input impedance of the feeding structure is 50𝛺 to achieve impedance matching, thereby reducing signal reflection and loss and ensuring efficient energy transmission.

[0034] Example 6: This example is basically the same as Example 5, except that: in this example, the upper base length of the first metal patch 3 is 4.8 mm, the lower base length is 13 mm, the height is 4 mm, and the thickness is 0.035 mm; the length of the second metal patch 4 is 13 mm, the width is 6 mm, and the thickness is 0.035 mm; the length of the first rectangular groove 9 is 5 mm, the width is 0.5 mm, and the distance between the left side of the first rectangular groove 9 and the left side of the second metal patch 4 is 1 mm. mm, the distance between the rear side of the first rectangular groove 9 and the rear side of the second metal patch 4 is 0.75 mm, the length of the second rectangular groove 10 is 1.5 mm, the width is 0.5 mm, the radius of the first fan-shaped groove 12 is 0.25 mm, the length of the fourth rectangular groove 14 is 8 mm, the width is 0.5 mm, the distance between the left side of the fourth rectangular groove 14 and the left side of the second metal patch 4 is 2.5 mm, the distance between the rear side of the fourth rectangular groove 14 and the rear side of the second metal patch 4 is 5 mm, the length of the fifth rectangular groove 15 is 1.5 mm, the width is 0.5 mm, the radius of the third fan-shaped groove 17 is 0.25 mm, the material of the dielectric substrate is FR-4, the dielectric constant The number is 4.4, the length of the rectangular plate 2 is 22 mm, the width is 13 mm, and the thickness is 0.8 mm, the length of the floor 20 is 8.7 mm, the width is 5.65 mm, and the thickness is 0.035 mm, the length of the electrical boundary plate 19 is 8.7 mm, the width is 5.65 mm, and the thickness is 0.035 mm, and the material of the floor 20 and the electrical boundary plate 19 are both copper; the length of the third metal patch 21 is 5.98 mm, the width is 1.35 mm, and the thickness is 0.035 mm, the length of the fourth metal patch 22 is 4.02 mm, the width is 1.17 mm, and the thickness is 0.035 mm; the material of the third metal patch 21 and the fourth metal patch 22 are both copper.

[0035] In order to verify the performance of the triple-notch independently reconfigurable ultra-wideband monopole antenna of the present invention, simulation software was used to implement the triple-notch independently reconfigurable ultra-wideband monopole antenna of the sixth embodiment of the present invention and perform simulation.

[0036] The triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention has a first adjustment capacitor with a capacitance of 0.5 pF, a second adjustment capacitor with a capacitance of 1 pF, and a third adjustment capacitor with a capacitance of 0.3 pF. Parameter diagram as shown Figure 4 As shown, analysis Figure 4It can be seen that after loading three adjustment capacitors and three U-shaped slots, the bandwidth of the three-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is 3.67GHz~11.12GHz. At the same time, the three-notch independent reconfigurable ultra-wideband monopole antenna of the present invention generates three notch points at 3.79GHz, 5.89GHz and 7.5GHz. At the notch points, the S11 of the three-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is higher than -10dB, and the notch selectivity is good. The surface current diagram of the three-notch independent reconfigurable ultra-wideband monopole antenna of the present invention at the 3.79GHz notch point is as follows Figure 5 As shown; Figure 5 The direction of the middle triangle arrow is the direction of current. The addition of the adjustable capacitor divides the original current path into two. The two current loops are 1 / 2 of the total length of the three U-shaped slots. Therefore, the total length of the three U-shaped slots is designed to be 1 / 4 of the wavelength at the notch frequency. The change in the capacitance value of the adjustment capacitor affects the equivalent current path and reactance value. A larger capacitance value will result in a lower notch frequency, while a smaller capacitance value will result in a higher notch frequency, thus making the notch frequency tunable.

[0037] The triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is configured such that the capacitance of the second adjustment capacitor and the capacitance of the third adjustment capacitor are fixed and the capacitance of the first adjustment capacitor changes. Parameter change diagram Figure 6 As shown, the triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention is configured such that the capacitance of the first adjustment capacitor and the capacitance of the third adjustment capacitor are fixed and the capacitance of the second adjustment capacitor is changed. Parameter change diagram Figure 7 As shown, the triple-notch independent reconfigurable ultra-wideband monopole antenna of the present invention has the first adjustment capacitor and the second adjustment capacitor fixed in capacitance, and the third adjustment capacitor changes in capacitance. Parameter change diagram Figure 8 As shown. Figure 6 It can be seen that, under the condition that other conditions remain unchanged, when the first adjustment capacitor C When the value of 1 is equal to 0.5pF, 0.7pF and 0.9pF respectively, the first notch point generated at the first U-shaped groove is located at 4.96GHz, 4.4GHz and 3.97GHz respectively, and the other two notch points generated at the second and third U-shaped grooves remain fixed; Figure 7 It can be seen that, under other conditions unchanged, when the second adjustable capacitor C When the 2 points are 0.5pF, 0.7pF, and 1.2pF, the second notch points generated at the second U-shaped groove are located at 4.46GHz, 5.52GHz, and 5.89GHz respectively, and the other two notch points generated at the first and third U-shaped grooves remain fixed; Figure 8It can be seen that, under the condition that other conditions remain unchanged, when the third adjustable capacitor C When the 3-point notch is divided into 0.4pF, 0.5pF, 0.8pF, and 0.9pF, the third notch points are located at 5.64GHz, 6.68GHz, and 6.89GHz respectively, and the other two notches generated by the first and second U-shaped grooves remain fixed;

[0038] In summary, the three notches created by the U-shaped slots can be independently tuned via corresponding adjustable capacitors, resulting in notches of varying frequencies. The remaining two notches remain essentially fixed, ensuring the independent reconfigurability of the three notches. Consequently, the three independently reconfigurable ultra-wideband monopole antenna of the present invention can adjust the three notches as needed, effectively suppressing frequency bands such as N79, C-band satellite services, and WLAN, offering significant advantages in anti-interference capabilities and spectrum utilization.

Claims

1. A triple-notch independent reconfigurable ultra-wideband monopole antenna, comprising a feed structure and an antenna radiating structure, wherein the feed structure is used to feed a signal into the antenna radiating structure, and the antenna radiating structure is used to radiate the signal fed into the feed structure into free space, characterized in that The antenna radiation structure is provided with three U-shaped slots, each of which enables the antenna radiation structure to achieve a half-wavelength resonant structure. Each U-shaped slot corresponds to a notch frequency. Each U-shaped slot causes the current flowing through it and corresponding to its notch frequency to be reversed, so that the radiation generated by the current flowing through it and corresponding to its notch frequency is offset and cannot be radiated through the antenna radiation structure. Each U-shaped slot is loaded with an adjustable capacitor. By adjusting the adjustable capacitor at each U-shaped slot, the path length and reactance of the current flowing through each U-shaped slot can be changed, thereby changing the notch frequency corresponding to each U-shaped slot; The antenna radiation structure is arranged on a dielectric substrate, and the dielectric substrate is formed by integrally forming an isosceles trapezoidal plate and a rectangular parallelepiped plate. The length direction of the rectangular parallelepiped plate is defined as the front-to-back direction, the width direction is defined as the left-to-right direction, and the thickness direction is defined as the up-down direction. The isosceles trapezoidal plate is located on the front side of the rectangular parallelepiped plate. The cross-section of the isosceles trapezoidal plate is an isosceles trapezoid. The upper base of the isosceles trapezoid is located in front of its lower base and is parallel to the front end face of the rectangular parallelepiped plate. The end face formed by the upper base of the cross-section of the isosceles trapezoidal plate is its front end face, and the end face formed by the lower base is its rear end face. The end faces formed by the two waists are its left and right end faces respectively. The rear end face of the isosceles trapezoidal plate completely coincides with the front end face of the rectangular parallelepiped plate. The antenna radiation structure includes two metal patches, which are respectively referred to as the first metal patch and the second metal patch. The shape and size of the first metal patch are exactly the same as the upper end face of the isosceles trapezoidal plate. The first metal patch is attached to the upper end face of the isosceles trapezoidal plate, completely covering the upper end face of the isosceles trapezoidal plate; the second metal patch is attached to the upper end face of the rectangular plate, the second metal patch is rectangular, and its length direction is along the left-right direction and its width direction is along the front-back direction. The length of the second metal patch is equal to the width of the rectangular plate, the width of the second metal patch is smaller than the length of the rectangular plate, and the front side of the second metal patch completely coincides with the lower bottom of the first metal patch; three U-shaped grooves are opened on the second metal patch On the sheet, the upper end surface of the rectangular plate is exposed at three U-shaped grooves, and the three U-shaped grooves are respectively called the first U-shaped groove, the second U-shaped groove and the third U-shaped groove. The notch of the first U-shaped groove and the notch of the third U-shaped groove are both set forward, the notch of the second U-shaped groove is set backward, and the second U-shaped groove is located in front of the first U-shaped groove and the third U-shaped groove; the plane that makes the rectangular plate left-right symmetrical is called the first symmetry plane; the first U-shaped groove is located on the left side of the first symmetry plane, and there is a distance between the two, and the third U-shaped groove is located on the right side of the first symmetry plane, and there is a distance between the two; the first U-shaped groove and the third U-shaped groove are left-right symmetrical with respect to the first symmetry plane; the second U-shaped groove is left-right symmetrical with respect to the first symmetry plane.

2. The triple-notch independent reconfigurable ultra-wideband monopole antenna according to claim 1, characterized in that The first U-shaped groove includes three rectangular grooves and two fan-shaped grooves with central angles of 180 degrees. The three rectangular grooves are respectively called the first rectangular groove, the second rectangular groove and the third rectangular groove, and the two fan-shaped grooves are respectively called the first fan-shaped groove and the second fan-shaped groove. The length direction of the first rectangular groove is along the left-right direction, and the width direction is along the front-back direction. The left side of the first rectangular groove is parallel to the plane where the left end face of the rectangular plate is located, and there is a distance between the two. The right side of the first rectangular groove is parallel to the first symmetry plane, and there is a distance between the two. The rear side of the first rectangular groove is located in front of the rear side of the second metal patch, and there is a distance between the two. The plane that makes the first rectangular groove left-right symmetrical is called the second symmetry plane. The second rectangular groove and the third rectangular groove are respectively located in front of the first rectangular groove. The length directions of the fan-shaped groove and the third rectangular groove are both along the front-to-back direction, and the width directions are both along the left-to-right direction. The second rectangular groove is located on the left side of the second symmetric plane, and the left side of the second rectangular groove is located in the same straight line as the left side of the first rectangular groove. The rear side of the second rectangular groove is connected to the front side of the first rectangular groove and is in a fitted state. There is a distance between the right side of the second rectangular groove and the second symmetric plane. The first fan-shaped groove is located on the front side of the second rectangular groove, and the chord of the first fan-shaped groove completely coincides with the front side of the second rectangular groove. The third rectangular groove and the second fan-shaped groove are both located on the right side of the second symmetric plane. The second rectangular groove and the third rectangular groove are bilaterally symmetrical about the second symmetric plane, and the first fan-shaped groove and the second fan-shaped groove are bilaterally symmetrical about the second symmetric plane.The second U-shaped groove includes three rectangular grooves and two fan-shaped grooves with central angles of 180 degrees. The three rectangular grooves are respectively called the fourth rectangular groove, the fifth rectangular groove and the sixth rectangular groove, and the two fan-shaped grooves are respectively called the third fan-shaped groove and the fourth fan-shaped groove. The length direction of the fourth rectangular groove is along the left-right direction, and the width direction is along the front-back direction. The fourth rectangular groove is left-right symmetrical about the first symmetry plane. The left side of the fourth rectangular groove is located on the left side of the second symmetry plane and on the right side of the straight line where the right side of the second rectangular groove is located. There is a distance between the left side of the fourth rectangular groove and the second symmetry plane and the straight line where the right side of the second rectangular groove is located. The front side of the fourth rectangular groove is located behind the front side of the second metal patch, and there is a distance between the two. The fifth rectangular groove and the sixth rectangular groove are respectively Located on the rear side of the fourth rectangular groove, the length directions of the fifth rectangular groove and the sixth rectangular groove are both along the front-to-back direction, and the width directions are both along the left-to-right direction. The left side of the fifth rectangular groove is in the same straight line as the left side of the fourth rectangular groove. The front side of the fifth rectangular groove is connected to the rear side of the fourth rectangular groove and is in a fitted state. The third fan-shaped groove is located on the rear side of the fifth rectangular groove, and the chord of the third fan-shaped groove completely coincides with the rear side of the fifth rectangular groove. There is a distance between the third fan-shaped groove and the front side of the first rectangular groove. The sixth rectangular groove and the fourth fan-shaped groove are both located on the right side of the first symmetry plane. The fifth rectangular groove and the sixth rectangular groove are bilaterally symmetrical with respect to the first symmetry plane, and the third fan-shaped groove and the fourth fan-shaped groove are bilaterally symmetrical with respect to the first symmetry plane. The adjustable capacitor loaded at the first U-shaped groove is called a first adjustable capacitor. The first adjustable capacitor is arranged in the middle of the first rectangular groove. One end of the first adjustable capacitor is connected to a part of the second metal patch located on the front side of the first rectangular groove, and the other end of the first adjustable capacitor is connected to a part of the second metal patch located on the rear side of the first rectangular groove; the adjustable capacitor loaded at the second U-shaped groove is called a second adjustable capacitor. The second adjustable capacitor is arranged in the middle of the fourth rectangular groove. One end of the second adjustable capacitor is connected to a part of the second metal patch located on the front side of the fourth rectangular groove, and the other end of the second adjustable capacitor is connected to a part of the second metal patch located on the rear side of the fourth rectangular groove; the adjustable capacitor loaded at the third U-shaped groove is called a third adjustable capacitor. The first adjustable capacitor and the third adjustable capacitor are bilaterally symmetrical about the first symmetry plane.

3. The triple-notch independent reconfigurable ultra-wideband monopole antenna according to claim 2, characterized in that It also includes an electric boundary plate and a floor. The electric boundary plate is used to bind electromagnetic waves so that the electromagnetic waves are transmitted in the feeding structure. The electric boundary plate is implemented by a rectangular metal patch. The length direction of the electric boundary plate is along the front-to-back direction, and the width direction is along the left-to-right direction. The electric boundary plate is attached to the upper end face of the rectangular plate and is located on the left side of the first symmetry plane. The rear side of the electric boundary plate and the rear end face of the rectangular plate are in the same plane. The left side of the electric boundary plate and the left end face of the rectangular plate are in the same plane. The front side of the electric boundary plate is located behind the rear side of the second metal patch, and there is a distance between the two. The electric The right side of the boundary plate is located to the right of the straight line where the right side of the fifth rectangular groove is located and to the left of the straight line where the left side of the third rectangular groove is located. There is a distance between the right side of the electrical boundary plate and the straight line where the right side of the fifth rectangular groove is located, and there is a distance between the right side of the electrical boundary plate and the straight line where the left side of the third rectangular groove is located. The floor is realized by a rectangular metal patch, the length direction of the floor is along the left-right direction, and the width direction is along the front-back direction. The floor is attached to the upper end surface of the rectangular plate; the floor is located to the right of the first symmetry plane, and the electrical boundary plate and the floor are left-right symmetrical about the first symmetry plane.

4. The triple-notch independent reconfigurable ultra-wideband monopole antenna according to claim 3, characterized in that The feeding structure includes two metal patches, which are respectively referred to as the third metal patch and the fourth metal patch. The third metal patch and the fourth metal patch are both rectangular, and their length directions are along the front-to-back direction, and their width directions are along the left-to-right direction. The third metal patch is attached to the upper end surface of the rectangular plate and is located between the electrical boundary plate and the floor. The rear side of the third metal patch is located in the same plane as the rear end surface of the rectangular plate. There is a distance between the left side of the third metal patch and the right side of the electrical boundary plate. There is a distance between the right side of the metal patch and the left side of the floor. The length of the third metal patch is less than the length of the electrical boundary plate. The fourth metal patch is attached to the upper end surface of the rectangular plate and is located on the front side of the third metal patch. The width of the fourth metal patch is less than the width of the third metal patch. The front side of the fourth metal patch is connected to the rear side of the second metal patch and is in a bonded state. The third metal patch is bilaterally symmetrical with respect to the first symmetry plane, and the fourth metal patch is bilaterally symmetrical with respect to the first symmetry plane.

5. The triple-notch independent reconfigurable ultra-wideband monopole antenna according to claim 4, characterized in that The upper bottom length of the first metal patch is 4.8mm, the lower bottom length is 13mm, the height is 4mm, and the thickness is 0.035mm. The length of the second metal patch is 13mm, the width is 6mm, and the thickness is 0.035mm. The length of the first rectangular groove is 5mm, the width is 0.5mm, the distance between the left side of the first rectangular groove and the left side of the second metal patch is 1mm, the distance between the back side of the first rectangular groove and the back side of the second metal patch is 0.75mm, the length of the second rectangular groove is 1.5mm, the width is 0.5mm, the radius of the first fan-shaped groove is 0.25mm, the length of the fourth rectangular groove is 8mm, the width is 0.5mm, the distance between the left side of the fourth rectangular groove and the left side of the second metal patch is 2.5mm, and the back side of the fourth rectangular groove is 0.75mm. The distance between them is 5mm, the length of the fifth rectangular groove is 1.5mm, the width is 0.5mm, the radius of the third fan-shaped groove is 0.25mm, the material of the dielectric substrate is FR-4, the dielectric constant is 4.4, the length of the rectangular plate is 22mm, the width is 13mm, and the thickness is 0.8mm, the length of the floor is 8.7mm, the width is 5.65mm, and the thickness is 0.035mm, the length of the electrical boundary plate is 8.7mm, the width is 5.65mm, and the thickness is 0.035mm, and the materials of the floor and the electrical boundary plate are both metal copper; the length of the third metal patch is 5.98mm, the width is 1.35mm, and the thickness is 0.035mm, the length of the fourth metal patch is 4.02mm, the width is 1.17mm, and the thickness is 0.035mm; the materials of the third metal patch and the fourth metal patch are both metal copper.

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