Dual antenna with ultra-wideband and high isolation and design method thereof

Abstract

The application discloses a binary antenna with ultra-wideband and high isolation and a design method thereof, and mainly solves the problem that the bandwidth of the existing traditional antenna is too narrow to adapt to the demand of a wideband communication system. The application comprises a dielectric substrate, a metal floor and two symmetrical cone monopole antennas and a symmetrically designed antenna decoupling matching network (DMN), wherein the DMN is formed by bending eleven groups of transmission lines with fixed length and width, the first seven groups are used for decoupling of the antenna, and the last four groups are used for matching adjustment. Through the DMN, high port isolation (> 20 dB) between the two cone monopole antennas is realized. The DMN designed in the application has high design freedom, and compared with other decoupling technologies, a wider decoupling bandwidth is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electromagnetic field and microwave technology, and relates to a binary antenna with super wide band and high isolation degree and a design method thereof. BACKGROUND

[0002] Multi-input multi-output (MIMO) antenna technology is widely used in 5G wireless communication systems to increase channel capacity, improve communication rate and reduce communication delay, etc., which requires high antenna isolation between antennas in a multi-antenna array. However, under the demand of modern technology development, antenna elements are usually placed in limited space. At this time, the increase of the number of antennas and the reduction of the distance between antennas will cause strong mutual coupling between adjacent antenna elements, resulting in strong electromagnetic interference and reducing the performance of the MIMO system. Therefore, how to simply and effectively improve the decoupling bandwidth of the MIMO antenna is a problem to be solved.

[0003] The existing methods for expanding the bandwidth of the antenna mainly include reducing Q value, modifying the equivalent circuit into a multi-resonant loop, improving the feeding mode, etc. However, reducing Q value is mainly achieved by increasing the thickness of the substrate, reducing the relative dielectric constant, and increasing the dielectric loss angle; the multi-resonant loop is mainly achieved by changing the shape of the patch, such as slot, U-shaped gap, additional coupling patch, etc. to increase the standing wave ratio bandwidth of the antenna, but this method will reduce the antenna efficiency; the improved feeding mode is achieved by electromagnetic coupling and additional impedance matching network to realize wide bandwidth. However, the decoupling and impedance matching functions of the decoupling network proposed in the past are designed separately, and even additional circuits are needed for matching, which not only increases the size of the antenna in the horizontal and vertical directions, but also increases the complexity of the design process. SUMMARY

[0004] The first object of the application is to provide a binary antenna with super wide band and high isolation degree to solve the problems of the prior art. The binary antenna with super wide band and high isolation degree not only realizes high isolation and wide bandwidth, but also has the impedance matching function built in the decoupling network, which solves the problem of complex design process of traditional super wide band decoupling matching network and is easily applicable to different antennas.

[0005] A binary antenna with super wide band and high isolation degree is provided, which is an axisymmetric structure and comprises:

[0006] a dielectric substrate (2);

[0007] a metal ground plate (3) located below the dielectric substrate (2);

[0008] an antenna main body (1) located above the dielectric substrate (2);

[0009] wherein,

[0010] The metal floor (3) is located on one side of the dielectric substrate (2) and leaves a clearance area;

[0011] The antenna main body (1) comprises two tapered monopole antennas (11) and an antenna decoupling and matching network (DMN) (12).

[0012] The antenna decoupling and matching network (12) comprises two axisymmetric antenna decoupling units, each of which is a multilayer structure and specifically comprises a first group to an eleventh group of transmission lines; one end of the first group of transmission lines LL1 is connected to the radiation port of one of the tapered monopole antennas (11), and the other end is connected to one end of the second group of transmission lines LL2 and one end of the third group of transmission lines LL3; the other end of the second group of transmission lines LL2 is connected to the other end of the second group of transmission lines LL2 in the other antenna decoupling unit; the other end of the third group of transmission lines LL3 is connected to one end of the fourth group of transmission lines LL4 and one end of the fifth group of transmission lines LL5; the other end of the fourth group of transmission lines LL4 is connected to the other end of the fourth group of transmission lines LL4 in the other antenna decoupling unit; the other end of the fifth group of transmission lines LL5 is connected to one end of the sixth group of transmission lines LL6 and one end of the seventh group of transmission lines LL7; the other end of the sixth group of transmission lines LL6 is connected to the other end of the sixth group of transmission lines LL6 in the other antenna decoupling unit; the other end of the seventh group of transmission lines LL7 is connected to one end of the eighth group of transmission lines LL8 and one end of the ninth group of transmission lines LL9; the other end of the eighth group of transmission lines LL8 is connected to the metal floor (3) through a through hole; the other end of the ninth group of transmission lines LL9 is connected to one end of the tenth group of transmission lines LL10 and one end of the eleventh group of transmission lines LL11; the other end of the tenth group of transmission lines LL10 is connected to the metal floor (3) through a through hole; and the other end of the eleventh group of transmission lines LL11 is used as a feeding port.

[0013] Preferably, part or all of the first group to the eleventh group of transmission lines are bent in different forms.

[0014] Preferably, the bending portions of the first group to the eleventh group of transmission lines are chamfered.

[0015] Preferably, the long side of the metal floor (3) is equal in length to the short side of the dielectric substrate (2).

[0016] Preferably, the center distance between the two tapered monopole antennas (11) is 0.124λ, where λ represents the wavelength corresponding to the center frequency 2.5GHz of the antenna operating frequency.

[0017] Preferably, the parameters of the transmission lines in the antenna decoupling and matching network (12) are as follows:

[0018] The first group of transmission lines (LL1) is 0.114λ long and 0.007λ wide;

[0019] The second group of transmission lines (LL2) is 0.075λ long and 0.0008λ wide;

[0020] The third group of transmission lines (LL3) is 0.1λ long and 0.01λ wide;

[0021] The fourth group of transmission lines (LL4) is 0.07λ long and 0.005λ wide;

[0022] The fifth group of transmission lines (LL5) is 0.172λ long and 0.122λ wide;

[0023] The sixth group of transmission lines (LL6) is 0.824λ long and 0.001λ wide;

[0024] The seventh group of transmission lines (LL7) is 0.325λ long and 0.01λ wide;

[0025] The eighth group of transmission lines (LL8) is 0.164λ long and 0.0025λ wide;

[0026] The ninth group of transmission lines (LL9) is 0.009λ long and 0.0024λ wide;

[0027] The tenth group of transmission lines (LL10) is 0.171λ long and 0.012λ wide;

[0028] The eleventh group of transmission lines (LL11) is 0.294λ long and 0.006λ wide.

[0029] Another object of the present application is to provide a design method of the antenna, comprising the following steps:

[0030] Step 1: Constructing the strongly coupled two-cone monopole antenna (11), obtaining the scattering parameters S 11 , S 12 , and then obtaining the odd and even mode admittances, the expressions of the odd and even mode admittances are as follows:

[0031]

[0032]

[0033] In the formula, G odd and G even are the odd mode and even mode of the strongly coupled two-cone monopole antenna (11), Y O and Y E are the odd mode admittance and even mode admittance of the strongly coupled two-cone monopole antenna (11);

[0034] Step 2: design a symmetrical antenna decoupling matching network (12) for the two strongly coupled conical monopole antennas (11), according to the odd mode model and the even mode model of the antenna decoupling matching network (12), taking the admittance Y and the electrical length e of each transmission line as variables, and taking the odd and even mode admittance of each layer of the decoupling matching network as intermediate quantities, to calculate the odd and even mode impedance of the decoupled conical monopole antennas (11);

[0035] The odd mode model of the antenna decoupling matching network (12) is that the second, fourth, and sixth groups of transmission lines of one antenna decoupling unit are disconnected from the second, fourth, and sixth groups of transmission lines of another antenna decoupling unit, and are instead connected to ground;

[0036] The even mode model of the antenna decoupling matching network (12) is that the second, fourth, and sixth groups of transmission lines of one antenna decoupling unit are disconnected from the second, fourth, and sixth groups of transmission lines of another antenna decoupling unit, and are instead left floating;

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] where Y1 to Y 11 are the admittance variables of the first to eleventh groups of transmission lines in the antenna decoupling matching network (12), respectively, e1, e3, e5, e7 to e11 are the electrical length variables of the first to eleventh groups of transmission lines in the antenna decoupling matching network (12) respectively; i is the imaginary unit; Y O and Y E are the odd mode admittance and the even mode admittance of the two strongly coupled conical monopole antennas (11) respectively; Y odd and Z odd are the odd mode admittance and the odd mode impedance of the decoupled antenna respectively; Y even and Zeven are the even mode admittance and the even mode impedance of the decoupled antenna respectively; Y o1 to Y o5 and Y e1 to Y e5 are intermediate variables for calculating Y odd and Y even ;

[0052] Step 3: taking the odd and even modes of the two decoupled conical monopole antennas (11) as intermediate values, the scattering parameters S 11 ' and S 12 ' of the two decoupled conical monopole antennas (11) are calculated from the odd and even mode impedances of the two decoupled conical monopole antennas (11) ;

[0053]

[0054]

[0055]

[0056]

[0057] where Γ odd and Γ even are the odd mode and the even mode of the decoupled antenna; Z is the characteristic impedance of the antenna, which is 50 ohms;

[0058] Step 4: in order to make the decoupled binary antenna array have a wide bandwidth and high isolation, the scattering parameters S 11 ' and S 12 ' of the decoupled antenna are taken as the optimization target to tend to 0, and the inductance and electrical length of each transmission line in the antenna decoupling matching network (12) are optimized to meet the target.

[0059] Compared with the prior art, the advantages of the present application are as follows:

[0060] (1) The decoupled antenna of the present application has a wider decoupling bandwidth, which can reach 1.02 GHz.

[0061] (2) The antenna decoupling matching structure is composed of eleven decoupling structures, and has higher design freedom.

[0062] (3) The application has simple structure, and the impedance matching is built in the decoupling network, so that separate design is not needed, and the realization is easier. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a planar structure schematic diagram of the decoupled binary conical monopole antenna array;

[0064] Figure 2 is a layer information diagram of the decoupled binary conical monopole antenna array;

[0065] Figure 3 is a topological principle diagram of the designed decoupling matching network;

[0066] Figure 4 is a topological principle diagram of the odd mode model of the designed decoupling matching network;

[0067] Figure 5 is a topological principle diagram of the even mode model of the designed decoupling matching network;

[0068] Figure 6 is a size annotation diagram of the designed decoupling matching network;

[0069] Figure 7 is an S parameter diagram of the binary conical monopole antenna array before decoupling;

[0070] Figure 8 is an S parameter diagram of the binary conical monopole antenna array after decoupling;

[0071] Marked in the figure: antenna body 1, dielectric substrate 2, metal floor 3, conical monopole antenna 11, antenna decoupling matching network 12. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical scheme and advantages of the application more clear and understandable, the application is further described in detail by combining specific examples and combining the drawings, but the application is not limited to these examples.

[0073] A binary antenna with super wide band and high isolation degree is an axisymmetric structure, such as Figures 1-2 Comprising:

[0074] Dielectric substrate 2; metal floor 3, located below the dielectric substrate 2; antenna body 1, located above the dielectric substrate 2; the metal floor 3 is located on one side of the dielectric substrate 2, and a clearance is left;

[0075] The antenna body 1 comprises two conical monopole antennas 11 and an antenna decoupling matching network DMN 12;

[0076] The antenna decoupling matching network 12 includes two axisymmetric antenna decoupling units, each of which is a multilayer structure and specifically includes a first group to an eleventh group of transmission lines; one end of the first group of transmission lines LL1 is connected to the radiation port of one of the two conical monopole antennas 11, and the other end is connected to one end of the second group of transmission lines LL2 and one end of the third group of transmission lines LL3; the other end of the second group of transmission lines LL2 is connected to the other end of the second group of transmission lines LL2 in the other antenna decoupling unit; the other end of the third group of transmission lines LL3 is connected to one end of the fourth group of transmission lines LL4 and one end of the fifth group of transmission lines LL5; the other end of the fourth group of transmission lines LL4 is connected to the other end of the fourth group of transmission lines LL4 in the other antenna decoupling unit; the other end of the fifth group of transmission lines LL5 is connected to one end of the sixth group of transmission lines LL6 and one end of the seventh group of transmission lines LL7; the other end of the sixth group of transmission lines LL6 is connected to the other end of the sixth group of transmission lines LL6 in the other antenna decoupling unit; the other end of the seventh group of transmission lines LL7 is connected to one end of the eighth group of transmission lines LL8 and one end of the ninth group of transmission lines LL9; the other end of the eighth group of transmission lines LL8 is connected to the metal floor 3 through a through hole; the other end of the ninth group of transmission lines LL9 is connected to one end of the tenth group of transmission lines LL10 and one end of the eleventh group of transmission lines LL11; the other end of the tenth group of transmission lines LL10 is connected to the metal floor 3 through a through hole; and the other end of the eleventh group of transmission lines LL11 is used as a feed port.

[0077] The first group to the seventh group of transmission lines of the antenna decoupling matching network 12 are used for antenna decoupling, and the eighth group to the eleventh group of transmission lines are used for matching adjustment.

[0078] The S parameter diagram of the two conical monopole antennas 11 after decoupling has three zero points, so that the decoupling bandwidth can reach 1.02 GHz.

[0079] The antenna decoupling matching network 12 is a three-layer parallel decoupling network, which basically corresponds to the three zero points of the scattering parameters of the antenna after decoupling.

[0080] The design method of the above-mentioned antenna includes the following steps:

[0081] Step 1: constructing two strongly coupled conical monopole antennas 11, obtaining the scattering parameters S 11 , S 12 of the two strongly coupled conical monopole antennas 11, and obtaining the odd and even mode admittances from the scattering parameters S 11 , S 12 ;

[0082] Step 2: Design a symmetrical antenna decoupling matching network 12 for the strong coupling of two conical monopole antennas 11, and according to the odd mode model and the even mode model of the antenna decoupling matching network 12, taking the admittance Y and the electrical length e of each transmission line as variables, and taking the odd and even mode admittance of each layer of the decoupling matching network as intermediate quantities, the odd and even mode impedances of the decoupled conical monopole antennas 11 are calculated; the odd and even mode impedance calculation process of the decoupled antenna is formula (3)-(16).

[0083] The odd mode model of the antenna decoupling matching network 12 is that the second, fourth and sixth groups of transmission lines of one antenna decoupling unit are disconnected from the second, fourth and sixth groups of transmission lines of another antenna decoupling unit, and are connected to ground; the odd mode model topological schematic diagram is shown in Figure 4 .

[0084] The even mode model of the antenna decoupling matching network 12 is that the second, fourth and sixth groups of transmission lines of one antenna decoupling unit are disconnected from the second, fourth and sixth groups of transmission lines of another antenna decoupling unit, and are suspended; the even mode model topological schematic diagram is shown in Figure 5 .

[0085] The topological schematic diagram of the first to eleventh groups of transmission lines in the antenna decoupling matching network 12 is shown in Figure 3 ;

[0086] Step 3: Taking the odd and even modes of the two decoupled conical monopole antennas 11 as intermediate values, the scattering parameters S 11 ' and S 12 ' of the two decoupled conical monopole antennas 11 are calculated according to the odd and even mode impedances, see formula (17)-(20).

[0087] Step 4: In order to make the decoupled binary antenna array have wide bandwidth and high isolation, taking the scattering parameters S 11 ' and S 12 ' of the decoupled antenna array to be 0 as the optimization target, the admittance and electrical length of each transmission line in the antenna decoupling matching network (12) that best meets the target are optimized.

[0088] Figure 6 The DMN specific size annotation diagram of the present application is shown in the figure, the system floor 3 is placed at the bottom, the width Wg is 50.19 mm, the length Lg is 77.37 mm, and the thickness hh is 0.035 mm. The medium substrate 2 has a length of Wg+d=84.06 mm, a width of Lg, and a thickness h of 0.508 mm. The thickness of the conical monopole antenna and the DMN is hh=0.035 mm, the center distance between the two monopole antennas is df=14.87 mm, and the length of the antenna is L=19 mm.

[0089] The length of the first group of transmission lines on the left and right sides of the symmetry axis is LL1=l1A+l1B=13.66 mm, and the line width is W1=0.88 mm.

[0090] The length of one side of the second group of transmission lines is LL2 = l2A + l2B + l2C + l2D + l2E + l2F = 9.03 mm, and the line width is W2 = 0.09 mm.

[0091] The length of both sides of the third group of transmission lines about the symmetry axis is LL3 = l3A + l3B + l3C = 11.78 mm, and the line width is W3 = 1.25 mm.

[0092] The length of one side of the fourth group of transmission lines is LL4 = l4A + l4B + l4C = 8.16 mm, and the line width is W4 = 0.65 mm.

[0093] The length of both sides of the fifth group of transmission lines about the symmetry axis is LL5 = l5A + l5B + l5C = 20.68 mm, and the line width is W5 = 1.46 mm.

[0094] The length of one side of the sixth group of transmission lines is LL6 = l6A + l6B + l6C + l6D = 9.89 mm, and the line width is W6 = 0.1407 mm.

[0095] The length of both sides of the seventh group of transmission lines about the symmetry axis is L7 = l7A + l7B + l7C + l7D + l7E + l7F = 39.00 mm, and the line width is W7 = 1.17 mm.

[0096] The length of both sides of the eighth group of transmission lines about the symmetry axis is LL8 = l8A + l8B + l8C + l8D + l8E = 19.71 mm, and the line width is W8 = 0.30 mm.

[0097] The length of both sides of the ninth group of transmission lines about the symmetry axis is LL9 = 1.06 mm, and the line width is W9 = 0.29 mm.

[0098] The length of both sides of the tenth group of transmission lines about the symmetry axis is LL10 = l10A + l10B = 20.55 mm, and the line width is W10 = 1.43 mm.

[0099] The length of one side of the eleventh group of transmission lines is LL11 = l11A + l11B + l11C + l11D + l11E + l11F + l11G = 35.34 mm, and the line width is W11 = 0.70 mm.

[0100] Figure 3 The topological principle diagram of the decoupling matching network is shown, and the length and width of each group of transmission lines are determined by the impedance and electrical length.

[0101] Figure 4 、 5 The odd mode and even mode topological principle diagrams of the designed decoupling matching network are shown, wherein Z O and Z EOdd mode impedance and even mode impedance of the original coupled binary tapered monopole antenna array, respectively

[0102] Figure 7 The S parameter diagram of the coupled binary tapered monopole antenna array used in the application has a matching bandwidth of 1.1 GHz.

[0103] Figure 8 The S parameter diagram of the decoupled binary tapered monopole antenna array has a decoupling bandwidth of 1.02 GHz.

[0104] The above only describes one embodiment of the application, which is used to help understand the method and core idea of the application. The design method of the binary antenna decoupling matching network based on ultra-wideband and high isolation degree proposed by the application can also be applied to other types of binary antenna arrays. It should be noted that, for those skilled in the art, improvements can be made to the application without departing from the principles of the application, and these improvements will fall within the scope of the claims of the application. The application is not limited to the scope of the specific embodiments, and for those skilled in the art, any changes within the spirit and scope of the application as defined in the appended claims are obvious, and all applications utilizing the concept of the application are within the scope of protection.

Claims

1. A binary antenna with ultra-wideband and high isolation, which is an axisymmetric structure, comprising: a dielectric substrate (2); a metal ground plate (3) located below the dielectric substrate (2); an antenna body (1) located above the dielectric substrate (2); wherein the metal ground plate (3) is located on one side of the dielectric substrate (2) and leaves a clearance; the antenna body (1) comprises two tapered monopole antennas (11) and an antenna decoupling matching network (12); the lower part of the two tapered monopole antennas (11) corresponds to the clearance, and the lower part of the antenna decoupling matching network (12) corresponds to the metal ground plate (3); characterized in that: the antenna decoupling matching network (12) comprises two axisymmetric antenna decoupling units, each of which is a multi-layer structure and specifically comprises a first group to an eleventh group of transmission lines; one end of the first group of transmission lines (LL1) is connected to the radiation port of one of the tapered monopole antennas (11), and the other end is connected to one end of the second group of transmission lines (LL2) and one end of the third group of transmission lines (LL3); the other end of the second group of transmission lines (LL2) is connected to the other end of the second group of transmission lines (LL2) in the other antenna decoupling unit; the other end of the third group of transmission lines (LL3) is connected to one end of the fourth group of transmission lines (LL4) and one end of the fifth group of transmission lines (LL5); the other end of the fourth group of transmission lines (LL4) is connected to the other end of the fourth group of transmission lines (LL4) in the other antenna decoupling unit; the other end of the fifth group of transmission lines (LL5) is connected to one end of the sixth group of transmission lines (LL6) and one end of the seventh group of transmission lines (LL7); the other end of the sixth group of transmission lines (LL6) is connected to the other end of the sixth group of transmission lines (LL6) in the other antenna decoupling unit; the other end of the seventh group of transmission lines (LL7) is connected to one end of the eighth group of transmission lines (LL8) and one end of the ninth group of transmission lines (LL9); the other end of the eighth group of transmission lines (LL8) is connected to the metal ground plate (3) through a via hole; the other end of the ninth group of transmission lines (LL9) is connected to one end of the tenth group of transmission lines (LL10) and one end of the eleventh group of transmission lines (LL11); the other end of the tenth group of transmission lines (LL10) is connected to the metal ground plate (3) through a via hole; and the other end of the eleventh group of transmission lines (LL11) is used as a feeding port. The first group to the eleventh group of transmission lines satisfy the following relationship: the first group to the eleventh group of transmission lines are partially or entirely bent in different forms. The first group to the eleventh group of transmission lines are chamfered at the bending positions. The long side of the metal ground plate (3) is equal in length to the short side of the dielectric substrate (2). The center distance between the two tapered monopole antennas (11) is 0.124λ, wherein λ represents the wavelength corresponding to the center frequency 2.5 GHz of the antenna operating frequency. The parameters of the transmission lines in the antenna decoupling matching network (12) are as follows: the first group of transmission lines (LL1) is 0.114λ long and 0.007λ wide; the second group of transmission lines (LL2) is 0.075λ long and 0.0008λ wide; the third group of transmission lines (LL3) is 0.1λ long and 0.01λ wide; ​ ​ ​ 2. The antenna of claim 1, wherein ​ （3） （4） （5） （6） （7） （8） （9） （10） （11） （12） （13） （14） （15） （16） wherein to Yi, i = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 are the admittance variables of the first to eleventh groups of transmission lines in the antenna decoupling matching network (12) respectively, , , , , , , to Yi, i = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 are the electrical length variables of the first to eleventh groups of transmission lines in the antenna decoupling matching network (12) respectively; i is the imaginary unit; and YoevenandYooodevenare the odd mode admittance and the even mode admittance of the two strongly coupled conical monopole antennas (11) respectively; and YoddandYoddare the odd mode admittance and the odd mode impedance of the decoupled antennas respectively; and YevenandYevenare the even mode admittance and the even mode impedance of the decoupled antennas respectively; to and to are the intermediate variables for calculating and are the intermediate variables for calculating 3. The antenna of claim 1, wherein ​ 4. The antenna of claim 3, wherein ​ 5. The antenna of claim 1, wherein ​ 6. The antenna of claim 1, wherein ​ 7. The antenna of claim 1, wherein ​ ​ ​ ​ The fourth group of transmission lines (LL4) is 0.07λ long and 0.005λ wide; The fifth group of transmission lines (LL5) is 0.172λ long and 0.122λ wide; The sixth group of transmission lines (LL6) is 0.824λ long and 0.001λ wide; The seventh group of transmission lines (LL7) is 0.325λ long and 0.01λ wide; The eighth group of transmission lines (LL8) is 0.164λ long and 0.0025λ wide; The ninth group of transmission lines (LL9) is 0.009λ long and 0.0024λ wide; The tenth group of transmission lines (LL10) is 0.171λ long and 0.012λ wide; The eleventh group of transmission lines (LL11) is 0.294λ long and 0.006λ wide.

8. The method of designing an antenna according to any one of claims 1-7, characterized in that The method comprises the following steps: Step 1: Constructing the strongly coupled two conical monopole antennas (11), the scattering parameters of the strongly coupled two conical monopole antennas (11) , The odd and even mode admittances are obtained, and the expression of the odd and even mode admittances is as follows: ， （1） ， （2） wherein and are the odd and even modes, respectively, of a strongly coupled pair of conical monopole antennas (11), and are the odd and even mode admittances, respectively, of a strongly coupled pair of conical monopole antennas (11). Step 2: design a symmetrical antenna decoupling matching network (12) for the two strongly coupled conical monopole antennas (11), according to the odd mode model and the even mode model of the antenna decoupling matching network (12), taking the admittance Y and the electrical length e of each segment of transmission line as variables, and taking the odd and even mode admittance of each layer of the decoupling matching network as intermediate quantities, to calculate the odd and even mode impedances of the decoupled conical monopole antennas (11); The odd mode model of the antenna decoupling matching network (12) is that the second, fourth and sixth groups of transmission lines of one antenna decoupling unit are disconnected from the second, fourth and sixth groups of transmission lines of another antenna decoupling unit, and are instead connected to ground; The even mode model of the antenna decoupling matching network (12) is that the second, fourth and sixth groups of transmission lines of one antenna decoupling unit are disconnected from the second, fourth and sixth groups of transmission lines of another antenna decoupling unit, and are instead left floating. （3） （4） （5） （6） （7） （8） （9） （10） （11） （12） （13） （14） （15） （16） wherein to are admittance variables of the first to eleventh groups of transmission lines in the antenna decoupling matching network (12), respectively, , , , , , , to are electrical length variables of the first to eleventh groups of transmission lines in the antenna decoupling matching network (12), respectively; i is the imaginary unit; and are odd-mode admittance and even-mode admittance of the two strongly coupled conical monopole antennas (11), respectively; and are odd-mode admittance and odd-mode impedance of the decoupled antennas, respectively; and are even-mode admittance and even-mode impedance of the decoupled antennas, respectively; to and to are intermediate variables for calculating and ​ Step 3: Calculate the scattering parameters of the two decoupled conical monopole antennas (11) from the odd and even mode impedances of the two decoupled conical monopole antennas (11) , ; （17） （18） （19） （20） wherein and is the decoupling of the odd and even modes of the antenna; is the characteristic impedance of the antenna Step 4: To make the decoupled binary antenna array have wide bandwidth and high isolation, the scattering parameters of the decoupled binary antenna array , tend to 0 as the optimization goal, and the inductance and electrical length of each transmission line in the antenna decoupling matching network (12) are optimized to meet the goal.

9. The method of designing an antenna of any of claim 8, wherein The value is 50 ohms.

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