Disclosure of Invention
The invention aims to provide the three-notch independent reconfigurable ultra-wideband monopole antenna which has three notch frequencies capable of being flexibly switched, can avoid three interference frequency bands by switching the three notch frequencies, and has the advantages that the three notch frequencies are adjustable, so that the frequency spectrum resource utilization rate can be improved, and the maintenance cost is reduced.
The three-notch independent reconfigurable ultra-wideband monopole antenna comprises a feed structure and an antenna radiation structure, wherein the feed structure is used for feeding signals into the antenna radiation structure, the antenna radiation structure is used for radiating signals fed into the feed structure to a free space, three U-shaped grooves are formed in the antenna radiation structure, each U-shaped groove can enable the antenna radiation structure to achieve a half-wavelength resonance structure, each U-shaped groove corresponds to one notch frequency, each U-shaped groove can cause inversion of current flowing through the U-shaped groove and corresponding to the notch frequency, radiation generated by the current flowing through the U-shaped groove and corresponding to the notch frequency is counteracted, the radiation cannot be radiated out through the antenna radiation structure, an adjustable capacitor is loaded in each U-shaped groove, and the path length and the reactance of the current flowing through each U-shaped groove can be changed by adjusting the adjustable capacitor in each U-shaped groove, so that the notch frequency corresponding to each U-shaped groove is changed.
Further, the antenna radiation structure is arranged on the dielectric substrate, the dielectric substrate is formed by integrally forming and connecting an isosceles trapezoid plate and a cuboid plate, the length direction of the cuboid plate is defined as the front-back direction, the width direction is defined as the left-right direction, the thickness direction is defined as the up-down direction, the isosceles trapezoid plate is positioned at the front side of the cuboid plate, the cross section of the isosceles trapezoid plate is an isosceles trapezoid, the upper bottom of the isosceles trapezoid is positioned at the front side of the lower bottom of the isosceles trapezoid plate and is parallel to the front end surface of the cuboid plate, the end surface formed by the upper bottom of the cross section of the isosceles trapezoid plate is the front end surface of the isosceles trapezoid plate, the end surface formed by the lower bottom is the rear end surface of the isosceles trapezoid plate, the end surfaces formed by the two waists are the left end surface and the right end surface of the isosceles trapezoid plate, and the front end surface of the isosceles trapezoid plate are completely overlapped; the antenna radiation structure comprises two metal patches, wherein the two metal patches are respectively called a first metal patch and a second metal patch, the shape and the size of the first metal patch are identical to those of the upper end face of the isosceles trapezoid plate, the first metal patch is attached to the upper end face of the isosceles trapezoid plate to completely cover the upper end face of the isosceles trapezoid plate, the second metal patch is attached to the upper end face of the cuboid plate, the second metal patch is rectangular, the length direction of the second metal patch is along the left-right direction, the width direction is along the front-back direction, the length of the second metal patch is equal to the width of the cuboid plate, the width of the second metal patch is smaller than the length of the cuboid plate, the first U-shaped groove is positioned on the left side of the first symmetrical plane, a distance is reserved between the first 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 arranged forward, the notch of the second U-shaped groove is arranged backward, the second U-shaped groove is positioned on the front side of the first U-shaped groove and the front side of the third U-shaped groove, a plane which enables the cuboid plate to be in bilateral symmetry is called a first symmetrical plane, the first U-shaped groove is positioned on the left side of the first symmetrical plane, a distance is reserved between the first U-shaped groove and the second U-shaped groove, the third U-shaped groove is positioned on the right side of the first symmetrical plane, a distance is reserved between the notch of the first U-shaped groove and the notch of the third U-shaped groove, and the second U-shaped groove are symmetrical planes about the first U-shaped groove and the third U-shaped groove.
Further, the first U-shaped groove comprises three rectangular grooves and two fan-shaped grooves with 180-degree central angles, and the three rectangular grooves are respectively called a first rectangular groove, The second rectangular groove and the third rectangular groove are respectively called a first rectangular groove and a second rectangular groove, the length direction of the first rectangular groove is along the left-right direction, the width direction is along the front-back direction, the left side edge of the first rectangular groove is parallel to the plane of the left end face of the cuboid plate, a distance is arranged between the left side edge of the first rectangular groove and the plane, the right side edge of the first rectangular groove is parallel to the first symmetrical plane, a distance is arranged between the right side edge of the first rectangular groove and the plane, the rear side edge of the first rectangular groove is positioned at the front side of the rear side edge of the second metal patch, a distance is arranged between the rear side edge of the first rectangular groove and the plane, the plane which enables the first rectangular groove to be in bilateral symmetry is called a second symmetrical plane, the second rectangular groove and the third rectangular groove are respectively positioned at the front side of the first rectangular groove, the length direction of the second rectangular groove and the third rectangular groove are all along the front-back direction, the width direction is along the left-right direction, the second rectangular groove is positioned at the left side of the second symmetrical surface, the left side edge of the second rectangular groove and the left side edge of the first rectangular groove are positioned at the same straight line, the rear side edge of the second rectangular groove is connected with the front side edge of the first rectangular groove and is in a fitting state, a distance is reserved between the right side edge of the second rectangular groove and the second symmetrical surface, the first fan-shaped groove is positioned at the front side of the second rectangular groove, the chord of the first fan-shaped groove is completely overlapped with the front side edge of the second rectangular groove, the third rectangular groove and the second fan-shaped groove are positioned at the left side of the second symmetrical surface, the second rectangular groove and the third rectangular groove are bilaterally symmetrical relative to the second symmetrical surface, the first fan-shaped groove and the second fan-shaped groove are bilaterally symmetrical relative to the second symmetrical surface, the second U-shaped groove comprises three rectangular grooves and two fan-shaped grooves with 180-degree central angles, and the three rectangular grooves are respectively called a fourth rectangular groove, A fifth rectangular groove and a sixth rectangular groove, the two fan-shaped grooves are respectively called a third fan-shaped groove and a fourth fan-shaped groove, the length direction of the fourth rectangular groove is along the left-right direction, the width direction is along the front-back direction, the fourth rectangular groove is bilaterally symmetrical with respect to the first symmetrical surface, the left side edge of the fourth rectangular groove is positioned on the left side of the second symmetrical surface and the right side of the straight line where the right side edge of the second rectangular groove is positioned, a distance is respectively arranged between the left side edge of the fourth rectangular groove and the second symmetrical surface and between the right side edge of the fourth rectangular groove and the straight line where the right side edge of the second rectangular groove is positioned, the front side edge of the fourth rectangular groove is positioned on the rear side of the front side edge of the second metal patch, a distance is arranged between the front side edge of the fourth rectangular groove and the fourth rectangular groove, the length direction of the fifth rectangular groove and the length direction of the sixth rectangular groove are along the front-back direction, the width direction of the fifth rectangular groove and the left side of the fourth rectangular groove are along the left-right direction, the left side of the fifth rectangular groove and the left side of the fourth rectangular groove are positioned in the same straight line, the front side of the fifth rectangular groove is connected with the rear side of the fourth rectangular groove and is in a fitting state, the third fan-shaped groove is positioned at the rear side of the fifth rectangular groove, the chord of the third fan-shaped groove is completely overlapped with the rear side of the fifth rectangular groove, a certain distance is reserved 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 positioned at the left side of the second symmetrical plane, the fifth rectangular groove and the sixth rectangular groove are in bilateral symmetry with respect to the second symmetrical plane, the third fan-shaped groove and the fourth fan-shaped groove are bilaterally symmetrical with respect to the second symmetrical surface, the adjustable capacitor loaded at the second U-shaped groove is called a first adjustable capacitor, the first adjustable capacitor is arranged at the middle of the first rectangular groove, one end of the first adjustable capacitor is connected with a part of the second metal patch, which is positioned at the front side of the first rectangular groove, the other end of the first adjustable capacitor is connected with a part of the second metal patch, which is positioned at 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 at the middle of the fourth rectangular groove, one end of the second adjustable capacitor is connected with a part of the second metal patch, which is positioned at the front side of the fourth rectangular groove, the other end of the second adjustable capacitor is connected with a part of the second metal patch, which is positioned at the rear side of the fourth rectangular groove, and the adjustable capacitor is called a third adjustable capacitor, which is positioned at the rear side of the fourth rectangular groove, is called a third adjustable capacitor, which is positioned at the right side of the fourth rectangular groove.
The three-notch independent reconfigurable ultra-wideband monopole antenna further comprises an electric boundary plate and a floor, wherein the electric boundary plate is used for realizing the restraint of electromagnetic waves and enabling the electromagnetic waves to be transmitted in a feed structure, the electric boundary plate is realized by adopting a rectangular metal patch, the length direction of the electric boundary plate is along the front-back direction, the width direction is along the left-right direction, the electric boundary plate is attached to the upper end face of the cuboid plate and is positioned at the left side of the first symmetrical plane, the rear side edge of the electric boundary plate and the rear end face of the cuboid plate are positioned at the same plane, the left side edge of the electric boundary plate and the left end face of the cuboid plate are positioned at the same plane, the front side edge of the electric boundary plate is positioned at the rear side of the rear side edge of the second metal patch, a distance is arranged between the electric boundary plate and the electric boundary plate, the right side edge of the electric boundary plate is positioned at the right side of a straight line of the fifth rectangular slot and the left side edge of the third rectangular slot, the distance is arranged between the electric boundary plate and the right side edge of the cuboid plate and the right side of the rectangular plate along the front side of the rectangular plate, and the distance is formed between the right side of the rectangular plate and the right side of the rectangular plate and the rectangular plate along the straight line of the right side of the rectangular plate.
Further, the feed structure include two metal patches, be called third metal patch and fourth metal patch respectively with these two metal patches, third metal patch with fourth metal patch all be the rectangle, and its length direction all along the fore-and-aft direction, the third metal patch attach and be in on the up end of cuboid board, and be located between electrical boundary plate and the floor, the rear side of third metal patch with the rear end face of cuboid board be located the coplanar, the left side of third metal patch with the right side of electrical boundary plate between have a distance, the right side of third metal patch with the left side of floor between have a distance, the length of third metal patch be less than the length of electrical boundary plate, fourth metal patch attach and be located on the up end of cuboid board, and be located the front side of third metal patch with the right side of third metal patch, the width of fourth metal patch is less than the right side of third metal patch and the right side of symmetry of fourth metal patch be the right side of symmetry, the fourth metal patch is the right side of symmetry.
Further, the upper bottom of the first metal patch is 4.8mm in length, the lower bottom is 13mm in length, the height is 4mm, the thickness is 0.035mm, the second metal patch is 13mm in length, the width is 6mm, the thickness is 0.035mm, the first rectangular groove is 5mm in length, the width is 0.5mm, the distance between the left side edge of the first rectangular groove and the left side edge of the second metal patch is 1mm, the distance between the rear side edge of the first rectangular groove and the rear side edge of the second metal patch is 0.75mm, the second rectangular groove is 1.5mm in length, the width is 0.5mm, the radius of the first rectangular groove is 0.25mm, the length of the fourth rectangular groove is 8mm, the width is 0.5mm, the distance between the left side edge of the fourth rectangular groove and the left side edge of the second metal patch is 2.5mm, the distance between the rear side edge of the fourth rectangular groove and the rear side edge of the second metal patch 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 cuboid plate is 22mm, the width is 13mm, the thickness is 0.8mm, the length of the floor plate is 8.7mm, the width is 5.65mm, the thickness is 0.035mm, the length of the electric boundary plate is 8.7mm, the width is 5.65mm, the thickness is 0.035mm, and the materials of the floor plate and the electric boundary plate are all metal copper; the length of the third metal patch is 5.98mm, the width of the third metal patch is 1.35mm, the thickness of the third metal patch is 0.035mm, the length of the fourth metal patch is 4.02mm, the width of the third metal patch is 1.17mm, and the thickness of the fourth metal patch is 0.035mm, and the third metal patch and the fourth metal patch are both made of metal copper.
Compared with the prior art, the invention has the advantages that the three U-shaped grooves are formed in the antenna radiation structure, each U-shaped groove can enable the antenna radiation structure to realize a half-wavelength resonance structure, each U-shaped groove corresponds to one notch frequency, each U-shaped groove can cause inversion of current flowing in the U-shaped groove and corresponding to the notch frequency, radiation generated by the current flowing in the U-shaped groove and corresponding to the notch frequency is counteracted, the radiation cannot be radiated out through the antenna radiation structure, an adjustable capacitor is loaded in each U-shaped groove, the path length and reactance of the current flowing in each U-shaped groove can be changed by adjusting the adjustable capacitor in each U-shaped groove, so that the notch frequency corresponding to each U-shaped groove is changed.
Detailed Description
The invention is described in further detail below with reference to the embodiments of the drawings.
In a first embodiment, as shown in fig. 1, a three-notch independent reconfigurable ultra-wideband monopole antenna includes a feed structure and an antenna radiation structure, the feed structure is used for feeding signals into the antenna radiation structure, the antenna radiation structure is used for radiating signals fed into the feed structure to free space, three U-shaped slots are formed in the antenna radiation structure, each U-shaped slot enables the antenna radiation structure to achieve a half-wavelength resonance structure, each U-shaped slot corresponds to one notch frequency, each U-shaped slot can cause inversion of current flowing through the U-shaped slot and corresponding to the notch frequency, radiation generated by current flowing through the U-shaped slot and corresponding to the notch frequency cannot be counteracted, adjustable capacitors are added at the U-shaped slots, and path length and reactance of current flowing through the U-shaped slots can be changed by adjusting the adjustable capacitors at the U-shaped slots, so that the notch frequency corresponding to the U-shaped slots is changed.
In this embodiment, the U-shaped groove may generate a notch characteristic, and in fact, a half-wavelength resonant structure is introduced, and the size of the U-shaped groove is designed according to the frequency to be filtered, so that the required notch frequency can be achieved. By loading an adjustable capacitor at each U-shaped slot, 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 parts, which increases the length and reactance of the current path, resulting in a change in the notch frequency, and thus a change in the notch frequency. The capacitance value of the adjustable capacitor can influence the current path and reactance in the U-shaped groove, the path length and reactance of the current flowing through each U-shaped groove can be changed by changing the capacitance value of the adjustable capacitor, and the three U-shaped grooves are mutually independent, so that the three notch frequencies can be independently adjusted.
In the second embodiment, the antenna radiation structure is arranged on a dielectric substrate, the dielectric substrate is formed by integrally forming an isosceles trapezoid plate 1 and a cuboid plate 2, the length direction of the cuboid plate 2 is defined as the front-back direction, the width direction is defined as the left-right direction, the thickness direction is defined as the up-down direction, the isosceles trapezoid plate 1 is positioned at the front side of the cuboid plate 2, the cross section of the isosceles trapezoid plate 1 is an isosceles trapezoid, the upper bottoms of the isosceles trapezoids are positioned at the front side of the lower bottoms of the isosceles trapezoids and are parallel to the front end surface of the cuboid plate 2, the end surface formed by the upper bottom of the cross section of the isosceles trapezoid plate 1 is the front end surface of the isosceles trapezoid plate, the end surface formed by the lower bottom is the rear end surface of the isosceles trapezoid plate, the end surfaces formed by two waists are the left end surface and the right end surface of the isosceles trapezoid plate 1 are completely overlapped with the front end surface of the cuboid plate 2; the antenna radiation structure comprises two metal patches, namely a first metal patch 3 and a second metal patch 4, wherein the shape and the size of the first metal patch 3 are identical to those of the upper end face of an isosceles trapezoid plate 1, the first metal patch 3 is attached to the upper end face of the isosceles trapezoid plate 1 to completely cover the upper end face of the isosceles trapezoid plate 1, the second metal patch 4 is attached to the upper end face of a cuboid plate 2, the second metal patch 4 is rectangular, the length direction of the second metal patch 4 is along the left-right direction, the width direction is along the front-back direction, the length of the second metal patch 4 is equal to the width of the cuboid plate 2, the width of the second metal patch 4 is smaller than the length of the cuboid plate 2, the front side edge of the second metal patch 4 is completely overlapped with the lower bottom of the first metal patch 3, three U-shaped grooves are formed in the first metal patch 3, the upper end face of the cuboid plate 2 is exposed at three U-shaped grooves, the three U-shaped grooves are respectively called a first U-shaped groove 5, a second U-shaped groove 6 and a third U-shaped groove 7, the notch of the first U-shaped groove 5 and the notch of the third U-shaped groove 7 are arranged forwards, the notch of the second U-shaped groove 6 is arranged backwards, the second U-shaped groove 6 is positioned at the front side of the first U-shaped groove 5 and the third U-shaped groove 7, a plane which enables the cuboid plate 2 to be bilaterally symmetrical is called a first symmetrical surface 8, the first U-shaped groove 5 is positioned at the left side of the first symmetrical surface 8, a distance is reserved between the first U-shaped groove 5 and the third U-shaped groove 7, the notch of the first U-shaped groove 5 and the notch of the third U-shaped groove 7 are bilaterally symmetrical with respect to the first symmetrical surface 8, and the second U-shaped groove 6 is bilaterally symmetrical with respect to the first symmetrical surface 8.
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 smaller than the notch frequency achieved by the third U-shaped groove 7.
In this embodiment, the rear end face of the second metal patch 4 in the antenna radiation structure is connected to the front end face of the fourth metal patch 22 in the feed structure, so as to ensure that the feed structure can effectively transmit electromagnetic waves into the antenna radiation structure. The antenna radiation structure is formed by integrally forming and connecting the first metal patch 3 in the isosceles trapezoid plate pattern and the second metal patch 4 in the cuboid plate pattern, and the antenna radiation structure presents an irregular shape, and the shape is favorable for scattering and radiating signals, so that the radiation gain of the antenna is improved. The antenna radiation structure increases the radiation area by using three U-shaped grooves, and can promote the broadband performance. When the feed structure feeds electromagnetic waves into the antenna radiating structure, surface currents are generated on the surface of the antenna radiating structure, and the overall current direction is the front-back direction, but the current direction is changed near the three U-shaped grooves. At a preset notch frequency, the first U-shaped groove 5 causes the current to reverse at the notch thereof, so that the currents near the first U-shaped groove 5 cancel each other, the radiation at the notch frequency thereof is canceled, a notch is generated, and the radiation of the signal at the notch frequency thereof is suppressed. At a preset notch frequency, the second U-shaped groove 6 causes the current to reverse at its notch, resulting in the currents near the second U-shaped groove 6 canceling each other, so that the radiation at its notch frequency is canceled, a notch is created, and the radiation of the signal at its notch frequency is suppressed. At a preset notch frequency, the third U-shaped groove 7 causes the current to reverse at its notch, resulting in the currents near the third U-shaped groove 7 canceling each other, so that the radiation at its notch frequency is canceled, a notch is created, and the radiation of the signal at its notch frequency is suppressed.
The third embodiment is basically the same as the second embodiment in that, as shown in fig. 2 and 3, the first U-shaped groove 5 includes three rectangular grooves and two fan-shaped grooves with 180 degrees central angles, and the three rectangular grooves are respectively referred to as a first rectangular groove 9, The second rectangular groove 10 and the third rectangular groove 11, the two fan-shaped grooves are respectively called a first fan-shaped groove 12 and a second fan-shaped groove 13, the length direction of the first rectangular groove 9 is along the left-right direction, the width direction is along the front-back direction, the left side edge of the first rectangular groove 9 is parallel to the plane of the left end face of the cuboid plate 2, a distance is arranged between the two, the right side edge of the first rectangular groove 9 is parallel to the first symmetrical surface 8, a distance is arranged between the two, the rear side edge of the first rectangular groove 9 is positioned at the front side of the rear side edge of the second metal patch 4, a distance is arranged between the two, the plane which enables the first rectangular groove 9 to be in bilateral symmetry is called a second symmetrical surface, the second rectangular groove 10 and the third rectangular groove 11 are respectively positioned at the front side of the first rectangular groove 9, the length directions of the second rectangular groove 10 and the third rectangular groove 11 are all along the front-back direction, the width direction is along the left-right direction, the second rectangular groove 10 is positioned at the left side of the second symmetrical surface, the left side edge of the second rectangular groove 10 and the left side edge of the first rectangular groove 9 are positioned in the same straight line, the rear side edge of the second rectangular groove 10 is connected with the front side edge of the first rectangular groove 9 and is in an attaching state, a certain distance is reserved between the right side edge of the second rectangular groove 10 and the second symmetrical surface, the first fan-shaped groove 12 is positioned at the front side of the second rectangular groove 10, the chord of the first fan-shaped groove 12 is completely overlapped with the front side edge of the second rectangular groove 10, the third rectangular groove 11 and the second fan-shaped groove 13 are positioned at the left side of the second symmetrical surface, the second rectangular groove 10 and the third rectangular groove 11 are in bilateral symmetry about the second symmetrical surface, and the first fan-shaped groove 12 and the second fan-shaped groove 13 are in bilateral symmetry about the second symmetrical surface; the second U-shaped groove 6 comprises three rectangular grooves and two fan-shaped grooves with 180 degrees central angles, the three rectangular grooves are respectively called a fourth rectangular groove 14, The fifth rectangular groove 15 and the sixth rectangular groove 16, the two fan-shaped grooves are respectively called a third fan-shaped groove 17 and a fourth fan-shaped groove 18, the length direction of the fourth rectangular groove 14 is along the left-right direction, the width direction is along the front-back direction, the fourth rectangular groove 14 is bilaterally symmetrical about the first symmetrical plane 8, the left side edge of the fourth rectangular groove 14 is positioned on the left side of the second symmetrical plane and the right side edge of the second rectangular groove 10 is positioned on the right side of a straight line, a distance is respectively arranged between the left side edge of the fourth rectangular groove 14 and the second symmetrical plane and between the right side edge of the second rectangular groove 10 and the straight line, the front side edge of the fourth rectangular groove 14 is positioned on the rear side of the front side edge of the second metal patch 4, a distance is arranged between the front side edge of the fourth rectangular groove 14 and the sixth rectangular groove 16 is positioned on the rear side of the fourth rectangular groove 14, the length direction of the fifth rectangular groove 15 and the length direction of the sixth rectangular groove 16 are along the front-back direction, the width direction is along the left-right direction, the left side edge of the fifth rectangular groove 15 and the left side edge of the fourth rectangular groove 14 are positioned on the same straight line, the front side edge of the fifth rectangular groove 15 is connected with the rear side edge of the fourth rectangular groove 14 and is in a fitting state, the third fan-shaped groove 17 is positioned at the rear side of the fifth rectangular groove 15, the chord of the third fan-shaped groove 17 is completely overlapped with the rear side edge of the fifth rectangular groove 15, a certain distance is reserved between the third fan-shaped groove 17 and the front side edge of the first rectangular groove 9, the sixth rectangular groove 16 and the fourth fan-shaped groove 18 are positioned at the left side of the second symmetrical surface, the fifth rectangular groove 15 and the sixth rectangular groove 16 are in bilateral symmetry about the second symmetrical surface, and the third fan-shaped groove 17 and the fourth fan-shaped groove 18 are in bilateral symmetry about the second symmetrical surface; the adjustable capacitor loaded at the first U-shaped groove 5 is called a first adjustable capacitor C1, the first adjustable capacitor C1 is arranged in the middle of the first rectangular groove 9, one end of the first adjustable capacitor C1 is connected with a part of the second metal patch 4 positioned on the front side of the first rectangular groove 9, the other end of the first adjustable capacitor C1 is connected with a part of the second metal patch 4 positioned on the rear side of the first rectangular groove 9, the adjustable capacitor loaded at the second U-shaped groove 6 is called a second adjustable capacitor C2, the second adjustable capacitor C2 is arranged in the middle of the fourth rectangular groove 14, one end of the second adjustable capacitor C2 is connected with a part of the second metal patch 4 positioned on the front side of the fourth rectangular groove 14, the other end of the second adjustable capacitor C2 is connected with a part of the second metal patch 4 positioned on the rear side of the fourth rectangular groove 14, the adjustable capacitor loaded at the third U-shaped groove 7 is called a third adjustable capacitor C3, and the first adjustable capacitor C1 and the third adjustable capacitor C3 are symmetric leftwards and rightwards about the first symmetric surface 8.
In this embodiment, the sum of the length of the first rectangular groove 9, the length of the second rectangular groove 10, the length of the third rectangular groove 11, the arc length of the first fan-shaped groove 12 and the arc length of the second fan-shaped groove 13 in the first U-shaped groove 5 is twice as long as the first U-shaped groove 5, and the length of the first U-shaped groove 5 is designed to be about half of the signal wavelength of the notch frequency thereof. The sum of twice the length of the fourth rectangular groove 14, twice the length of the fifth rectangular groove 15 and twice the length of the sixth rectangular groove 16 in the second U-shaped groove 6, the arc length of the third fan-shaped groove 17 and the arc length of the fourth fan-shaped groove 18 is taken as the length of the second U-shaped groove 6, and the length of the second U-shaped groove 6 is designed to be about half of the signal wavelength of its notch frequency.
The length of the third U-shaped groove 7 is equal to the length of the first U-shaped groove 5, about half the signal wavelength of its notch frequency. Under the preset notch frequency of the U-shaped groove, the phase relation between the current and the electric field can change, so that the current in the U-shaped groove is reversed, and partial currents in the U-shaped groove are mutually counteracted to form a notch. The three adjustable capacitors cause the current to need to pass through the adjustable capacitors as it moves around the three U-shaped slots, the original current path being split in two, which increases the length and reactance of the current path, resulting in a change in the notch frequency. The capacitance value of each adjustable capacitor can influence the current path and reactance in the U-shaped groove where the adjustable capacitor is located, so that the notch frequency of the U-shaped groove where the adjustable capacitor is located is changed, and the notch frequency adjustable function is realized. According to the principle of half-wave resonance structure, the longer the designed length of the U-shaped groove is, the smaller the notch frequency is. Wherein the second U-shaped groove 6 is designed to be longer and has a smaller notch frequency than the first U-shaped groove 5 and the third U-shaped groove 7. The first U-shaped groove 5 is designed to be short in length and its notch frequency is large relative to the second U-shaped groove 6. The length of the third U-shaped groove 7 is consistent with that of the first U-shaped groove 5, and the preset notch frequency of the third U-shaped groove is higher than that of the first U-shaped groove 5 by adjusting the adjustable capacitance at the third U-shaped groove. The first U-shaped groove 5 and the third U-shaped groove 7 are bilaterally symmetrical about the first symmetrical plane 8, and the second U-shaped groove 6 is bilaterally symmetrical about the first symmetrical plane 8. The second U-shaped groove 6 is arranged at the corresponding position of the middle positions of the first U-shaped groove 5 and the third U-shaped groove 7 so as to optimize the mutual influence between the first U-shaped groove 5 and the third U-shaped groove and avoid mutual interference. Meanwhile, symmetry of the three U-shaped grooves in the whole three-notch independent reconfigurable ultra-wideband monopole antenna is maintained, directivity and gain of the three-notch independent reconfigurable ultra-wideband monopole antenna can be improved, and smoother frequency response can be achieved through uniform distribution of the three U-shaped grooves.
In the present embodiment, the three-notch independent reconfigurable ultra-wideband monopole antenna further comprises an electric boundary plate 19 and a floor 20, wherein the electric boundary plate 19 is used for realizing constraint of electromagnetic waves and transmitting the electromagnetic waves in a feed structure, the electric boundary plate 19 is realized by adopting a rectangular metal patch, the length direction of the electric boundary plate 19 is along the front-back direction, the width direction is along the left-right direction, the electric boundary plate 19 is attached to the upper end surface of the cuboid plate 2 and is positioned at the left side of the first symmetrical surface 8, the rear side edge of the electric boundary plate 19 and the rear end surface of the cuboid plate 2 are positioned at the same plane, the left side edge of the electric boundary plate 19 and the left end surface of the cuboid plate 2 are positioned at the same plane, the front side edge of the electric boundary plate 19 is positioned at the rear side of the rear side edge of the second metal patch 4, a distance is arranged between the electric boundary plate 19 and the right side edge of the fifth rectangular slot 15, a distance is arranged between the right side edge of the fifth rectangular slot 15 and the right side edge of the third rectangular slot 11, and a distance is arranged between the right side edge of the fifth rectangular slot 15 and the right side edge of the fifth rectangular slot 11; the floor 20 is realized by rectangular metal patches, the length direction of the floor 20 is along the left-right direction, the width direction is along the front-back direction, the floor 20 is attached to the upper end surface of the cuboid plate 2, the floor 20 is positioned on the right side of the first symmetrical plane 8, and the electric boundary plate 19 and the floor 20 are in bilateral symmetry about the first symmetrical plane 8.
In this embodiment, the material of the electrical boundary plate and the floor is a metal conductor, the electric field of the electromagnetic wave is perpendicular to the floor 20, and the current is perpendicular to the electric field and parallel to the floor 20. The electric boundary plate and the floor can restrict the fed electromagnetic wave to be transmitted in the feed structure, so that the electromagnetic wave cannot radiate outwards, energy is consumed, and the performance of the antenna is improved.
In the fifth embodiment, the feeding structure includes two metal patches, which are respectively referred to as a third metal patch 21 and a fourth metal patch 22, the third metal patch 21 and the fourth metal patch 22 are rectangular, the length directions of the two metal patches are all along the front-back direction, the width directions of the two metal patches are all along the left-right direction, the third metal patch 21 is attached to the upper end surface of the rectangular parallelepiped plate 2 and is located between the electric boundary plate 19 and the floor 20, the rear side edge of the third metal patch 21 is located on the same plane with the rear end surface of the rectangular parallelepiped plate 2, a distance is provided between the left side edge of the third metal patch 21 and the right side edge of the electric boundary plate 19, the right side edge of the third metal patch 21 and the left side edge of the floor 20 are provided with a distance, the length of the third metal patch 21 is smaller than the length of the electric boundary plate 19, the fourth metal patch 22 is attached to the upper end surface of the rectangular parallelepiped plate 2, the width of the fourth metal patch 22 is smaller than the width of the third metal patch 21, the width of the fourth metal patch 22 is located on the front side of the rectangular parallelepiped plate 21, the fourth metal patch 22 is located on the right-left side and the right side of the rectangular parallelepiped plate 2, the fourth metal patch 22 is symmetric about the front side edge of the fourth metal patch 21 and the fourth metal patch is symmetric about the fourth metal patch 8, and the fourth metal patch 8 is symmetric about the right side surface of the fourth metal patch 8.
In this embodiment, the feeding structure adopts CPW feeding, and the feeding structure is fed from bottom to top, and the input impedance of the feeding structure is matched with that of a 50Ω coaxial line.
In this embodiment, the feeding structure is capable of transmitting signals, and feeding signals into the antenna radiation structure from bottom to top, and the input impedance of the feeding structure is 50Ω, so as to achieve impedance matching, so as to reduce signal reflection and loss, and ensure efficient energy transmission.
Example six: this embodiment is substantially the same as embodiment five except that: in this embodiment, the length of the upper bottom of the first metal patch 3 is 4.8mm, the length of the lower bottom is 13mm, the height is 4mm, the thickness is 0.035mm, the length of the second metal patch 4 is 13mm, the width is 6mm, the thickness is 0.035mm, the length of the first rectangular groove 9 is 5mm, the width is 0.5mm, the distance between the left side edge of the first rectangular groove 9 and the left side edge of the second metal patch 4 is 1mm, the distance between the rear side edge of the first rectangular groove 9 and the rear side edge of the second metal patch 4 is 0.75mm, the length of the second rectangular groove 10 is 1.5mm, the width is 0.5mm, the radius of the first fan-shaped groove 12 is 0.25mm, the length of the fourth rectangular groove 14 is 8mm, the width is 0.5mm, the distance between the left side edge of the fourth rectangular groove 14 and the left side edge of the second metal patch 4 is 2.5mm, the distance between the rear side edge of the fourth rectangular groove 14 and the rear side edge of the second metal patch 4 is 5mm, the fifth rectangular groove 14 is 5.5 mm, the width is 0.35 mm, the thickness of the electric board is 0.25mm, the thickness of the thickness is 0.25mm, the length of the electric board is 8mm, the length of the thickness of the front rectangular groove is 8mm, and the thickness, the length of the length and the and the the third metal patch 21 has a length of 5.98mm, a width of 1.35mm and a thickness of 0.035mm, the fourth metal patch 22 has a length of 4.02mm, a width of 1.17mm and a thickness of 0.035mm, and the third metal patch 21 and the fourth metal patch 22 are both made of metallic copper.
In order to verify the performance of the triple-notch independent reconfigurable ultra-wideband monopole antenna, simulation software is adopted to realize and simulate the triple-notch independent reconfigurable ultra-wideband monopole antenna of the sixth embodiment of the invention.
The three-notch independent reconfigurable ultra-wideband monopole antenna of the invention has the advantages that the capacitance value of the first adjusting capacitor is 0.5pF, the capacitance value of the second adjusting capacitor is 1pF, the capacitance value of the third adjusting capacitor is 0.3pF, the S11 parameter chart is shown in figure 4, after the three adjusting capacitors and the three U-shaped grooves are loaded, the bandwidth of the three-notch independent reconfigurable ultra-wideband monopole antenna of the invention is 3.67 GHz-11.12 GHz, three notch points are generated at the positions of 3.79GHz, 5.89GHz and 7.5GHz, the S11 of the three-notch independent reconfigurable ultra-wideband monopole antenna of the invention at the notch is higher than-10 dB, and the selectivity of the notch is good. The surface current diagram of the three-notch independent reconfigurable ultra-wideband monopole antenna at the 3.79GHz notch point is shown in fig. 5, the direction of a triangular arrow in fig. 5 is the current direction, the original current path is divided into two parts by adding an adjustable capacitor, and two current loops are respectively 1/2 of the total length of three U-shaped grooves, so that the total length of the three U-shaped grooves is designed to be 1/4 of the wavelength at the notch frequency, the change of the capacitance value of the adjustable capacitor affects the equivalent current path and the reactance value, the larger capacitance value can lead to lower notch frequency, and the smaller capacitance value can lead to higher notch frequency, and therefore the notch frequency is tunable.
The S11 parameter change diagram of the triple-notch independent reconfigurable ultra-wideband monopole antenna in the invention when the capacitance value of the second adjusting capacitor and the capacitance value of the third adjusting capacitor are fixed is shown in fig. 6, the S11 parameter change diagram of the triple-notch independent reconfigurable ultra-wideband monopole antenna in the invention when the capacitance value of the first adjusting capacitor and the capacitance value of the third adjusting capacitor are fixed is shown in fig. 7, the capacitance value of the first adjusting capacitor and the capacitance value of the second adjusting capacitor are fixed, and the S11 parameter change diagram of the triple-notch independent reconfigurable ultra-wideband monopole antenna in the invention when the capacitance value of the third adjusting capacitor is changed is shown in fig. 8. As can be seen from fig. 6, under the condition that other conditions are unchanged, when the value of the first adjustable capacitance C1 is equal to 0.5pF, 0.7pF and 0.9pF, respectively, the first notch point generated at the first U-shaped groove is respectively located at 4.96GHz, 4.4GHz and 3.97GHz, and the remaining two notch points generated at the second U-shaped groove and the third U-shaped groove are kept fixed, while under the condition that other conditions are unchanged, when the second adjustable capacitance C2 is divided into 0.5pF, 0.7pF and 1.2pF, the second notch point generated at the second U-shaped groove is respectively located at 4.46GHz, 5.52GHz and 5.89GHz, and the remaining two notch points generated at the first U-shaped groove and the third U-shaped groove are respectively located at 4.96GHz, 4.4GHz and 3.97 GHz;
In summary, the notch points generated by the three U-shaped grooves can be independently tuned by the corresponding adjustable capacitors, so that notch points with different frequencies are generated, and the other two notch points are basically kept fixed, thereby meeting the independent reconfigurable performance of the three notch points. Therefore, the three-notch independent reconfigurable ultra-wideband monopole antenna can adjust three notch points according to use requirements, effectively inhibit frequency bands such as n79, C-band satellite service, WLAN and the like, and has great advantages in the aspects of anti-interference capability and spectrum utilization rate.