Miniaturized ultra-wideband antenna with trapped wave

Abstract

The invention belongs to the field of ultra-wideband antennas, and provides a miniaturized ultra-wideband antenna with trapped waves, which basically structurally comprises a dielectric substrate, a radiation unit and a microstrip feeder which are attached to one side of the dielectric substrate, and a grounding plate attached to the other side of the dielectric substrate. The radiation unit is formed by combining a circle and a polygon, and a U-shaped notch groove is formed in the radiation unit and used for suppressing electromagnetic waves of unneeded frequency bands. The grounding plate is provided with a second-order Minkowski fractal groove which is used for impedance optimization of the antenna. The ultra-wideband antenna provided by the invention is a monopole antenna, a Teflon ZYF300CA-C high-frequency plate is selected, the size of the antenna is 22mm * 28mm * 0.76 mm, the dielectric constant Dk of a substrate is 2.94, and the loss tangent Df is 0.0016; and the impedance of the microstrip feeder is 50 ohms. According to the invention, trapped waves can be generated near a 5.5 GHz frequency point, and S11lt can be satisfied in a frequency range of 3.47 to 4.92 GHz and a frequency range of 5.83 to 13.54 GHz; and-10 dB. The antenna has the characteristics of miniaturization, ultra wide band, omnidirectivity and low profile, and can be applied to an ultra wide band (UWB) communication technology.

Description

Technical Field

[0001] The invention belongs to the field of ultra-wideband antennas, and in particular relates to a miniaturized ultra-wideband antenna with notch waves. Background Art

[0002] Ultra-wideband (UWB) communication technology is a wireless carrier communication technology with a frequency bandwidth of 500MHz or above. With its rapid development, UWB positioning technology has also emerged. UWB positioning technology is an advanced wireless communication technology based on ultra-wideband communication technology and mainly used for indoor positioning functions. The UWB positioning system is a specific application form of UWB positioning technology. The units in the UWB positioning system exchange information through ultra-wideband antennas, so the ultra-wideband antenna is an important part of the UWB positioning system and has become a popular type of antenna research.

[0003] Since the UWB frequency band is relatively wide, according to the regulations of the Federal Communications Commission (FCC), the UWB frequency band ranges from 3.1 to 10.6 GHz. However, in the actual application of UWB positioning technology, antennas with such wide bandwidth are not required. Too wide bandwidth is not conducive to the interference suppression of UWB communication on other types of communication frequency bands, but has an adverse effect. In addition, if the bandwidth of the UWB antenna is too wide, especially the low frequency point is too low, the antenna size will be larger, which will be unfavorable for some application scenarios with miniaturization requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to design a miniaturized ultra-wideband antenna with notch that can be used in a UWB positioning system.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A miniaturized ultra-wideband antenna with notch wave comprises: a dielectric substrate 3, a radiation unit 1 attached to the upper surface of the dielectric substrate 3, a microstrip feed line 2, and a ground plate 4 attached to the lower surface of the dielectric substrate 3, wherein: The radiation unit 1 is bilaterally symmetrical with the vertical central axis of the upper surface of the dielectric substrate 3 as the central axis. The shape of the radiation unit 1 is a combination of a circle and two symmetrical right-angled trapezoidal patterns. A wave trap groove 5 is provided in the radiation unit 1. The microstrip feed line 2 has one end connected to the radiation unit and the other end extending to the edge of the dielectric substrate; The ground plate 4 is bilaterally symmetrical with the vertical central axis of the lower surface of the dielectric substrate 3 as the central axis, and the ground plate is rectangular in shape, one side of the rectangle is located at the edge of the dielectric substrate 3, and a fractal groove 6 is provided at the center of the other side opposite to the rectangle; A rectangular feeding surface 7 is provided on the side of the dielectric substrate 3 , and the rectangular feeding surface 7 is connected to the microstrip feed line 2 and the ground plate 4 .

[0006] Furthermore, the radiation unit 1 has a specific structure as follows: The two right-angled trapezoids are symmetrically arranged, the upper bases of the two right-angled trapezoids are respectively adjacent to and parallel to the edges of the dielectric substrate on both sides, the lower bases of the two right-angled trapezoids are both coincident with the vertical central axis of the upper surface of the dielectric substrate, the right-angled waists of the two right-angled trapezoids are both adjacent to and parallel to the edges of the dielectric substrate, and the intersection of the oblique waists and the lower bases is on the circumference of the circle; The notch groove 5 is located in the circle and has a "U-shape" shape, with the opening of the "U-shape" facing the right-angle waists of the two right-angle trapezoids, and both ends of the notch groove 5 are located on the edges of the circle.

[0007] Furthermore, the fractal groove 6 provided on the ground plate 4 is a second-order Minkowski fractal groove, wherein: The first-order fractal is a square; The second-order fractal is composed of three small squares extending from the centers of the three sides of the first-order fractal, with side lengths being one-third of the first-order fractal square.

[0008] Furthermore, the dielectric substrate 3 is made of Teflon ZYF300CA-C high-frequency plate, with a size of 22 mm×28 mm×0.76 mm, a dielectric constant Dk of 2.94, and a loss tangent Df of 0.0016.

[0009] Furthermore, the radiation unit has a size of: The distance La between the edge of the radiation unit and the edge of the dielectric substrate is 0.2 mm; The distance L2 from the lower edge of both sides of the radiation unit to the bottom of the radiation unit is 5.5 mm; The radius R of the circular part of the radiation unit is 7 mm; The overall length L1 of the notch groove is 6 mm; The overall width W1 of the notch groove is 10 mm; The groove width Lt of the notch groove is 0.5 mm; The distance Lx from the top of the notch groove to the edge of the dielectric substrate is 2.5 mm.

[0010] Furthermore, the microstrip feed line 2 is a microstrip line with a characteristic impedance of 50 ohms and a width of 1.9 mm.

[0011] Furthermore, the ground plate 4 is in the shape of a rectangle of 22 mm×13.5 mm; the second-order Minkowski fractal groove has a first-order fractal square side length of 2 mm and a second-order fractal small square side length of 2 / 3 mm.

[0012] Based on the above technical solution, the present invention has the following advantages and beneficial effects: The present invention performs bandwidth limitation and notch design on the UWB antenna. Bandwidth limitation is to design the impedance bandwidth of the antenna to the bandwidth actually required in the UWB positioning system, and notch design is to filter part of the frequency band of the UWB antenna, thereby achieving a certain anti-interference ability. In addition, the present invention effectively optimizes the impedance of the antenna in the low-frequency part by improving the shape of the radiation unit of the monopole ultra-wideband antenna and adding a fractal groove on the ground plate, thereby realizing the miniaturization of the antenna.

[0013] The antenna of the present invention has the characteristics of miniaturization, ultra-wideband, omnidirectionality and low profile, and can be applied to ultra-wideband (UWB) communication technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the overall structure of the antenna according to an embodiment of the present invention.

[0015] Figure 2 Dimensional diagram of the antenna according to an embodiment of the present invention ((a) is a top view, and (b) is a bottom view).

[0016] Figure 3 4 is the S parameter simulation result of the antenna according to the embodiment of the present invention.

[0017] Figure 4 3D far-field radiation pattern of the antenna of the embodiment of the present invention at a frequency of 4.0 GHz.

[0018] Figure 5 3D far-field radiation pattern of the antenna according to the embodiment of the present invention at a frequency of 6.5 GHz.

[0019] Figure 6 3D far-field radiation pattern of the antenna according to the embodiment of the present invention at a frequency of 8.0 GHz.

[0020] Figure 7 This is a diagram showing the electric field strength distribution of the antenna according to an embodiment of the present invention at a frequency of 4.0 GHz.

[0021] Figure 8 This is a diagram showing the electric field strength distribution of the antenna according to an embodiment of the present invention at a frequency of 5.54 GHz.

[0022] Fig. 9 This is a diagram showing the electric field strength distribution of the antenna according to an embodiment of the present invention at a frequency of 6.5 GHz.

[0023] Fig.10 This is a diagram showing the electric field strength distribution of the antenna according to an embodiment of the present invention at a frequency of 8.0 GHz.

[0024] Reference numerals: Radiating unit 1, microstrip feed line 2, dielectric substrate 3, ground plate 4, notch groove 5, fractal groove 6, rectangular feeding surface 7. DETAILED DESCRIPTION

[0025] The technical solution provided by the present application will be further described below in conjunction with specific embodiments and accompanying drawings. The advantages and features of the present application will become more apparent with the following description.

[0026] refer to Figure 1 A miniaturized ultra-wideband antenna with notch wave comprises: a dielectric substrate 3, a radiation unit 1 attached to the upper surface of the dielectric substrate 3, a microstrip feed line 2, and a ground plate 4 attached to the lower surface of the dielectric substrate 3. Wherein: The dielectric substrate 3 is made of Teflon ZYF300CA-C high-frequency plate, with a size of 22 mm×28 mm×0.76 mm, a dielectric constant Dk of 2.94, and a loss tangent Df of 0.0016.

[0027] The radiation unit 1 is made of metal and is bilaterally symmetrical with the vertical center axis of the upper surface of the dielectric substrate 3 as the center axis. The shape of the radiation unit 1 is a combination of a circle and two symmetrical right-angled trapezoidal patterns. A wave trap groove is provided in the radiation unit 1.

[0028] Specifically, the shape of the radiation unit 1 is a combination of a circle and two symmetrical right-angled trapezoids. The circle is the original shape of the radiation unit. In order to make full use of the space on the dielectric substrate, the two symmetrical right-angled trapezoids are combined with the circle into a new shape, thereby expanding the impedance bandwidth of the antenna in the low-frequency part. The two right-angled trapezoids are symmetrically arranged, the upper bases of the two right-angled trapezoids are respectively adjacent to and parallel to the edges of the two sides of the dielectric substrate, the lower bases of the two right-angled trapezoids are both coincident with the vertical central axis of the upper surface of the dielectric substrate, the right-angled waists of the two right-angled trapezoids are both adjacent to and parallel to the edge of the dielectric substrate, the intersection of the oblique waist and the lower base is on the circumference of the circle, and the center of the circle is located on the lower base of the right-angled trapezoid. Among them, the lower base of the right-angled trapezoid is 5.5mm longer than the upper base, and the radius of the circle is 7mm.

[0029] Specifically, a "U-shaped" wave trap groove 5 is provided on the radiation unit 1. The wave trap groove 5 is located in a circle, symmetrical with the vertical center axis of the dielectric substrate 3 as the center axis, and the opening of the "U-shape" faces the right-angle waists of the two right-angle trapezoids. The groove width of the wave trap groove 5 is 0.5 mm.

[0030] The microstrip feed line 2 has one end connected to the radiation unit and the other end extending to the edge of the dielectric substrate. The microstrip feed line 2 is a microstrip line with a characteristic impedance of 50 ohms and a width of 1.9 mm.

[0031] The ground plate 4 is made of metal and is bilaterally symmetrical with the vertical center axis of the lower surface of the dielectric substrate 3 as the center axis. Specifically, the ground plate 4 is in the shape of a rectangle of 22 mm×13.5 mm, one side of the rectangle is located at the edge of the dielectric substrate 3, and a fractal groove 6 is provided at the center of the other side opposite to the side, which is used to optimize the antenna impedance, specifically a second-order Minkowski fractal groove, wherein: the first-order fractal is a square with a side length of 2 mm; the second-order fractal is three small squares with a side length of 2 / 3 mm extended from the center of the three sides of the first-order fractal, and the side length is one-third of the first-order fractal square.

[0032] A rectangular feeding surface 7 is provided on the side of the dielectric substrate, and the rectangular feeding surface 7 is connected to the microstrip feed line 2 and the ground plate 4 .

[0033] The specific dimensions of the antenna are shown in the figure below. Figure 2 , Figure 2 (a) is a schematic diagram of the antenna from above, and (b) is a schematic diagram of the antenna from above. Figure 2 The specific values ​​of the corresponding size parameters of the antenna.

[0034] Table 1 in, W0 is the antenna width; L0 is the antenna length; La is the distance between the edge of the antenna radiation unit and the edge of the dielectric substrate; L1 is the overall length of the notch groove; W1 is the overall width of the notch groove; Lx is the distance from the top of the notch groove to the edge of the dielectric substrate; L2 is the distance from the lower edge of both sides of the radiation unit to the bottom of the radiation unit; R is the radius of the circular part of the radiation unit; Lt is the groove width of the notch groove; Wk is the width of the microstrip feed line; Lg is the length of the ground plate; d is the side length of the first-order fractal square of the second-order Minkowski fractal groove of the ground plate.

[0035] refer to Figure 3 , which is a simulation diagram of the reflection coefficient S11 of the antenna input port of an embodiment of the present invention. It can be seen from the figure that the antenna satisfies S11<-10dB in the 3.47~4.92GHz and 5.83~13.54GHz frequency bands, and satisfies S11>-10dB in the 4.93~5.83GHz frequency band, which is a notch frequency band.

[0036] refer to Figure 4, which is a 3D simulation diagram of the far-field radiation of the antenna of an embodiment of the present invention at a frequency of 4.0 GHz.

[0037] refer to Figure 5 , which is a 3D simulation diagram of the far-field radiation of the antenna of an embodiment of the present invention at a frequency of 6.5 GHz.

[0038] refer to Figure 6 , which is a 3D simulation diagram of the far-field radiation of the antenna of an embodiment of the present invention at a frequency of 8.0 GHz.

[0039] Depend on Figure 4 , Figure 5 , Figure 6 It can be seen that the antenna of the present invention meets the radiation characteristics of an omnidirectional antenna.

[0040] refer to Figure 7 , is a diagram showing the electric field strength distribution of the antenna of an embodiment of the present invention at a frequency of 4.0 GHz.

[0041] refer to Figure 8 , is a diagram showing the electric field strength distribution of the antenna of an embodiment of the present invention at a frequency of 5.54 GHz.

[0042] refer to Fig. 9 , is a diagram showing the electric field strength distribution of the antenna of an embodiment of the present invention at a frequency of 6.5 GHz.

[0043] refer to Fig.10 , is a diagram showing the electric field strength distribution of the antenna of an embodiment of the present invention at a frequency of 8.0 GHz.

[0044] Depend on Figure 7~Figure 10 By comparison, it can be seen that in the notch frequency band, the notch groove design of the present invention can well suppress the electromagnetic waves in the notch frequency band and play a filtering role.

[0045] The above description is only a description of the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be deemed as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present application.

Claims

1. A miniaturized ultra-wideband antenna with a notch, characterized in that: include: A dielectric substrate (3), a radiation unit (1) and a microstrip feeder (2) attached to the upper surface of the dielectric substrate (3), and a grounding plate (4) attached to the lower surface of the dielectric substrate (3), wherein: The radiation unit (1) is bilaterally symmetrical with the vertical central axis of the upper surface of the dielectric substrate (3) as the central axis; the shape of the radiation unit (1) is a combination of a circle and two symmetrical right-angled trapezoidal patterns; a wave trapezoid groove (5) is provided in the radiation unit (1); The microstrip feed line (2) has one end connected to the radiation unit (1) and the other end extending to the edge of the dielectric substrate (3); The grounding plate (4) is bilaterally symmetrical with the vertical central axis of the lower surface of the dielectric substrate (3) as the central axis. The grounding plate (4) is rectangular in shape, one side of the rectangle is located at the edge of the dielectric substrate (3), and a fractal groove (6) is provided at the center of the other side opposite to the rectangle. A rectangular feeding surface (7) is provided on the side of the dielectric substrate (3), and the rectangular feeding surface (7) is connected to the microstrip feed line (2) and the grounding plate (4).

2. A miniaturized ultra-wideband antenna with notch as claimed in claim 1, characterized in that: The radiation unit (1) has a specific structure as follows: The two right-angled trapezoids are symmetrically arranged, the upper bases of the two right-angled trapezoids are respectively adjacent to and parallel to the edges of the dielectric substrate on both sides, the lower bases of the two right-angled trapezoids are both coincident with the vertical central axis of the upper surface of the dielectric substrate, the right-angled waists of the two right-angled trapezoids are both adjacent to and parallel to the edge of the dielectric substrate, the intersection of the oblique waists and the lower bases is on the circumference of the circle, and the center of the circle is located on the lower base of the right-angled trapezoid; The wave trap groove (5) is located in the circle and has a "U" shape, with the opening of the "U" facing the right-angled waists of the two right-angled trapezoids.

3. A miniaturized ultra-wideband antenna with notch as claimed in claim 1, characterized in that: The fractal groove (6) provided on the ground plate (4) is a second-order Minkowski fractal groove, wherein: The first-order fractal is a square; The second-order fractal is composed of three small squares extending from the centers of the three sides of the first-order fractal, with side lengths being one-third of the first-order fractal square.

4. A miniaturized ultra-wideband antenna with notch as claimed in claim 1, characterized in that: The dielectric substrate (3) is made of Teflon ZYF300CA-C high-frequency plate, with a size of 22 mm×28 mm×0.76 mm, a dielectric constant Dk of 2.94, and a loss tangent Df of 0.0016.

5. A miniaturized ultra-wideband antenna with notch as claimed in claim 2, characterized in that: The radiation unit (1) has a size of: The distance La between the edge of the radiation unit and the edge of the dielectric substrate is 0.2 mm; The distance L2 from the lower edge of both sides of the radiation unit to the bottom of the radiation unit is 5.5 mm; The radius R of the circular part of the radiation unit is 7 mm; The overall length L1 of the notch groove is 6 mm; The overall width W1 of the notch groove is 10 mm; The groove width Lt of the notch groove is 0.5 mm; The distance Lx from the top of the notch groove to the edge of the dielectric substrate is 2.5 mm.

6. A miniaturized ultra-wideband antenna with notch as claimed in claim 1, characterized in that: The microstrip feed line (2) is a microstrip line with a characteristic impedance of 50 ohms and a width of 1.9 mm.

7. A miniaturized ultra-wideband antenna with notch as claimed in claim 3, characterized in that: The ground plate (4) is in the shape of a rectangle of 22 mm x 13.5 mm; The second-order Minkowski fractal groove has a first-order fractal square side length of 2 mm and a second-order fractal small square side length of 2 / 3 mm.

Images