A dual-band broadband high-gain printed omnidirectional antenna based on multimode resonance

Abstract

The present invention proposes a dual-band, broadband, high-gain printed omnidirectional antenna based on multimode resonance, comprising a metal sheet-loaded printed antenna, a feed coaxial line, a metal sleeve, and a radome. The main body of the antenna is the metal sheet-loaded printed antenna, and the basic unit on the printed antenna is a planar printed conical dipole antenna for generating broadband omnidirectional radiation. The coaxial unit printed antennas are arrayed on a vertical plane to generate high gain, and a central parallel feeding method is used to achieve equal amplitude and phase feeding, forming a synthesis of two antenna elements. Current perturbation is achieved by loading a semi-cylindrical metal sheet on the side of the printed dipole antenna, thereby enhancing the high-order harmonic characteristics of the antenna in the high frequency band and having good impedance matching characteristics, thereby forming dual-band radiation characteristics. The integrated design of the radiating oscillator and the feeding network greatly reduces the impact of the feeding network on the omnidirectional radiation, and optimizes the width of the printed PCB as much as possible, so that it has excellent omnidirectional non-circularity. The main body of the antenna is integrally printed and directly serves as a support for the loaded metal sheet, eliminating the need for an additional support structure, resulting in a simple structure and extremely light weight.

Description

Technical Field

[0001] The present invention relates to an omnidirectional antenna, in particular to a dual-frequency, broadband, high-gain printed omnidirectional antenna based on multi-mode resonance. Background Art

[0002] For communication systems, enabling point-to-point communication and data transmission is crucial. Omnidirectional antennas, with their 360° horizontal beam coverage, enable smooth communication between any number of stations. This is why they are widely used in mobile communications and other data link systems. The basic form of an omnidirectional antenna is a dipole antenna, which resonates at half the electrical wavelength and is typically narrowband. This, to a certain extent, limits its application in broadband systems. However, with the advancement of antenna technology, an increasing number of broadband antennas have been developed, expanding the application range of omnidirectional antennas. Even if omnidirectional antennas using half-wave dipoles achieve broadband, their gain is limited. Generally, the gain of such omnidirectional antennas is around 0 dBi, limiting their application in applications requiring higher gain. Consequently, there is a growing demand for high-gain broadband omnidirectional antennas. To achieve this, larger-diameter omnidirectional antennas are typically arrayed in the vertical plane to achieve high gain. This broadbandization is achieved through the use of larger-diameter unit omnidirectional antennas, while the height of the unit antennas does not exceed the wavelength of the corresponding high frequency, thus facilitating antenna array formation. With the promotion and application of portable and miniaturized systems, more and more systems require omnidirectional antennas to comprehensively consider requirements such as small size, light weight, wide bandwidth, multiple frequency bands, and high gain. These requirements are also mutually restrictive, which brings great challenges to the research and development of omnidirectional antennas.

[0003] The current main implementation methods and their shortcomings for miniaturized, dual-band, broadband, and high-gain omnidirectional antennas are as follows:

[0004] Wideband antennas, such as a wideband biconical antenna with a height exceeding two wavelengths and a diameter exceeding two wavelengths, can be used to cover the required dual-frequency resonances through ultra-wideband, while also achieving relatively high gain. However, this approach is large in size and weight, making it difficult to meet miniaturization requirements; and the gain is only 1-2 dB higher than that of a conventional dipole antenna.

[0005] The implementation method adopts a composite method of two sets of broadband high-gain omnidirectional antennas. For example, broadband high-gain antennas are designed to work with low frequencies and high frequencies respectively, which are described as F1 high-gain omnidirectional antenna and F2 high-gain omnidirectional antenna. The two antennas are placed one above the other, such as the F1 high-gain omnidirectional antenna is located on top of the F2 high-gain omnidirectional antenna. The two antennas are placed coaxially, thus forming a dual-band, broadband, high-gain omnidirectional antenna. However, in this implementation, the feeding RF cable of the F1 high-gain omnidirectional antenna needs to pass through the F2 high-gain omnidirectional antenna, which affects the impedance characteristics and omnidirectionality of the F2 high-gain omnidirectional antenna. This implementation usually has two output ports. If a single-port output is required, a duplexer is required to combine the two ports into a single port. The design of the duplexer is also very complicated, so this design is difficult and the antenna manufacturability is not good. At the same time, the height of the antenna needs to consider the height of the F1 high-gain omnidirectional antenna and the F2 high-gain omnidirectional antenna, the size of the duplexer, the size required for the transition from the output of the two antennas to the duplexer wiring, and the transition size required from the output of the duplexer to the output port. The height dimension of the antenna is large and cannot meet the requirements of miniaturization. The antenna has many components, each of which has a certain weight, and its weight cannot meet the requirements of lightweighting.

[0006] The implementation method adopts a dual-band directional antenna combination, such as designing a directional miniaturized radiating unit, which is described as a dual-band directional broadband radiating unit. It is formed by arranging 4 units (or more) in the vertical direction, and the maximum radiation direction of each antenna unit differs by 90° (in the azimuth plane), thereby forming a dual-band, high-gain omnidirectional antenna equivalent to 4 units. Since the directional radiation unit usually has a wider radiation plate, the array is formed by rotating the azimuth plane, which makes the antenna have a larger diameter and a higher height than the pure omnidirectional implementation. The antenna is composed of 4 units, which requires an additional combiner to synthesize into a single-port output, which is relatively complicated to implement. The paths of the 4-unit antenna to the power divider are different, and they require equal-amplitude and same-phase feeding to achieve efficient synthesis. This requires the use of RF cables with the same phase to feed the 4 units. This means that for the antenna unit farther away from the combiner, its feeding cable can be directly pulled in the height direction, while the feeding cable of the antenna unit closest to the combiner needs to be wrapped before it can be connected to the combiner. The routing relationship is relatively complex, and the production of equal-phase cables itself is difficult. Therefore, this implementation method is more difficult to produce. At the same time, considering that the antenna has many components, the weight of the antenna cannot meet the requirements of lightweight. Summary of the Invention

[0007] The problem to be solved by this application is to overcome the deficiencies of the above-mentioned prior art and realize the requirements of miniaturization, lightness, dual-band, wide bandwidth and high gain of omnidirectional antenna.

[0008] To solve the above problems, the present invention proposes a dual-band, broadband, high-gain printed omnidirectional antenna based on multimode resonance, comprising a PCB printed antenna 1, a loading metal sheet 2, a feeding coaxial line 3, a metal sleeve 4, and an antenna cover 5; wherein the PCB printed antenna 1 is located inside the antenna cover 5, the loading metal sheet 2 is located on the side of the PCB printed antenna 1 and is also located inside the antenna cover 5, the PCB printed antenna 1 and the loading metal sheet 2 are the radiating parts of the antenna, forming a structure of a two-element dipole antenna vertical array; the core wire of the feeding coaxial line 3 is electrically connected to one side of the PCB printed antenna 1 , the sheathed wire of the feed coaxial line 3 is electrically connected to the other side of the PCB printed antenna 1 to achieve effective feeding of the antenna; the bottom of the feed coaxial line 3 is connected to the metal sleeve 4 through a flange, and the RF connector passes through the bottom of the metal sleeve 4 to serve as the output port of the antenna; the metal sleeve 4 is a cylindrical structure, and its bottom is connected to the RF connector flange of the feed coaxial line 3; the antenna cover 5 is a fiberglass circular tube, the bottom of which is inserted into the inner side of the metal sleeve 4 and fixed, and it passes through the PCB printed antenna 1, the loading metal sheet 2, and the feed coaxial line 3, covering it in the cover, thereby forming a complete antenna structure.

[0009] The above-mentioned printed dual-band broadband high-gain omnidirectional antenna adopts a planar printed conical dipole antenna as the basic radiation unit, utilizes the double-layer structure of the dielectric substrate to make the copper layers on the front and back sides into a microstrip line transmission structure, and utilizes the 180° phase difference between the front and back sides of the microstrip line to feed the antenna, thereby realizing basic dipole antenna radiation; the two-unit planar printed conical dipole antenna adopts parallel feeding, and is fed at the exact center of the two-unit planar printed conical dipole antenna through a coaxial cable, and the feeding energy is transmitted by an equal-length microstrip line to realize equal amplitude and same-phase feeding of the two-unit dipole antenna, thereby obtaining the best synthesis efficiency and realizing a high-gain omnidirectional antenna; by loading the basic radiation unit on the PCB antenna with a metal sheet of appropriate size, the antenna is fed with a coaxial cable at the exact center of the two-unit planar printed conical dipole antenna. The design achieves secondary resonance characteristics, and the size of the loading piece is designed to adjust the resonance point to the frequency band where it needs to work, thereby realizing dual-band and wideband operation; the loading design of the basic radiation unit also expands the effective electrical size of the radiation oscillator, expands the resonance bandwidth, and enhances the original bandwidth of the antenna; through the reasonable design of the antenna, the two resonant frequency points of the antenna can meet its own array element synthesis conditions, and both high and low frequencies can obtain good gain enhancement effects; the antenna achieves broadband and dual-band broadband characteristics without increasing the envelope size, and it is miniaturized and portable; in addition, the antenna is implemented in PCB printing form, is very light in weight, meets the portability requirements, and has fewer parts, which is convenient for installation, debugging, and production.

[0010] Furthermore, the planar printed conical dipole antenna is a two-dimensional form of the conical dipole antenna. It has similar wide-band characteristics to the conical dipole antenna and is equivalent to the conical dipole antenna. However, due to its two-dimensional structure, it has great advantages in size and weight and is easy to print on the PCB board, forming a planar printed conical dipole antenna attached to the PCB, which is conducive to achieving the antenna's miniaturization and lightweight requirements.

[0011] Furthermore, a PCB substrate is used as the structural support for the planar conical dipole antenna. By printing the upper and lower oscillators on the front and back of the PCB, respectively, the planar printed conical dipole antenna is fed via microstrip lines on the front and back of the PCB. The front microstrip line connects the upper oscillator (defined as a phase of 0°), and the back microstrip line connects the lower oscillator (with a phase of 180° relative to the upper oscillator). This is equivalent to the coaxial cable feeding scenario where the core wire of the coaxial cable connects the upper oscillator and the sheath wire connects the lower oscillator. By implementing feeding via microstrip lines printed on the PCB, there is no need to add additional feeding components, achieving an integrated design for antenna radiation and feeding. At the same time, this integrated design approach also allows the design of feeding to be considered during antenna design, allowing the two to achieve maximum impedance matching, helping the antenna achieve the most efficient radiation effect.

[0012] Furthermore, the antenna uses two sets of planar printed conical dipole antennas for array design, achieving an increase in gain compared to a single dipole antenna. Since the single planar printed conical dipole antenna is a half-wave oscillator, according to antenna principles, it has a gain of about 2dBi. The gain can usually be enhanced by increasing the radiator, such as expanding the antenna into a dipole form of 1 wavelength. The biconical antenna in actual engineering uses this principle. However, considering impedance matching, it needs to be accompanied by an increase in diameter, and the diameter usually needs to be more than 0.5 wavelengths. With this increase in diameter, the size and weight increase significantly. If a two-dimensional form is used, its horizontal non-circularity will worsen, and the normal gain of the wide surface will be much greater than the normal gain of the narrow surface. This solution uses two sets of planar printed conical dipole antennas for array design, achieving an omnidirectional high gain of 4~5dBi. Since the diameter of the antenna has not increased, it has a good horizontal non-circularity, realizing a high-gain omnidirectional antenna.

[0013] Furthermore, a design using two sets of planar printed conical dipole antennas arrayed in the vertical plane theoretically increases the gain of the two-element array by 2-3dB. Furthermore, the antenna units of the two-element planar printed conical dipole antenna array in the vertical plane are all omnidirectional, and they are synthesized only in the vertical plane, maintaining the antenna's omnidirectional radiation characteristics in the horizontal plane. By compressing the vertical plane's directional pattern, the antenna's gain in the horizontal plane is enhanced, resulting in a high-gain omnidirectional antenna.

[0014] Furthermore, the two sets of planar printed conical dipole antennas and the feed network are printed on the same PCB, minimizing processing errors and installation tolerances between the two, resulting in excellent amplitude and phase consistency. The feed network is also designed simultaneously with the two sets of planar printed conical dipole antennas, minimizing network insertion loss and impedance matching loss, all of which ensure high antenna synthesis efficiency.

[0015] Furthermore, a 50-ohm universal coaxial cable is used for RF feeding. The core wire of the coaxial cable is connected to the front microstrip line, and the sheath wire is connected to the back microstrip line. The present application can also use coaxial cables with different characteristic impedances. By adjusting the parameters of the antenna and the feeding microstrip line, the characteristic impedance of the antenna and the input port are impedance matched.

[0016] Furthermore, the feed coaxial line is soldered to the back microstrip line through multiple connection points, and solder pads are added on the bottom of the PCB. This not only ensures a good electrical connection between the coaxial line and the microstrip line, but also makes them structurally integrated, facilitating the installation of the antenna body, base, and radome.

[0017] Furthermore, a semi-cylindrical metal sheet is loaded on the side of the planar printed conical dipole antenna, the main function of which is to strengthen the current disturbance on the antenna and enhance the high-order resonance of the planar printed conical dipole antenna, so that it can obtain better broadband impedance matching, realize the dual-band, broadband radiation characteristics of the antenna, and obtain the dual-band broadband voltage standing wave ratio and antenna gain; at the same time, since the loaded metal sheet is semi-cylindrical, the projection width of the narrow side of the planar printed conical dipole antenna is increased, further improving the omnidirectional shape of the antenna, and having extremely low omnidirectional non-circularity.

[0018] The technical effects achieved by the present invention are embodied in the following aspects:

[0019] The use of a planar printed conical dipole antenna utilizes the better broadband characteristics of the conical dipole antenna compared to the ordinary cylindrical dipole antenna, so that the antenna unit of the present application has a better impedance bandwidth;

[0020] A wide semi-cylindrical metal sheet is loaded on the side of a planar printed conical dipole antenna to stimulate the antenna's higher-order resonant modes. By adjusting parameters such as the size and loading position of the metal sheet, a higher impedance matching characteristic is achieved at the higher-order mode position, forming a dual-band characteristic.

[0021] The designed planar printed conical dipole antenna unit has a small PCB width and a small horizontal projection, resulting in good horizontal omnidirectional radiation characteristics. Two units are arranged in a vertical array to maintain horizontal omnidirectional radiation while compressing the vertical beam to increase antenna gain, thus achieving a high-gain omnidirectional antenna.

[0022] The two planar printed conical dipole antenna elements and the feed network are printed on the same PCB board, maximizing the amplitude and phase consistency between the radiating elements, reducing the insertion loss of the feed network, and improving the impedance matching characteristics, thereby achieving good antenna synthesis efficiency and ensuring high gain characteristics;

[0023] The antenna is loaded with wide semi-cylindrical metal sheets on the sides, forming a structure equivalent to a cylindrical loading sheet, which improves the antenna's omnidirectional non-circularity. The feed network is arranged in the center to reduce the impact of the feed network's introduced current radiation on the omnidirectional performance, ensuring the antenna has excellent omnidirectional characteristics.

[0024] The spacing of the two-element planar printed conical dipole antenna is rationally adjusted to achieve the synthesis efficiency of both the main resonance and higher-order resonance frequency bands, with high antenna gain in both frequency bands.

[0025] The printed PCB antenna itself is lightweight, and when used as a supporting structure for the metal element, no additional support is required, thus maximizing the antenna's lightweight characteristics.

[0026] The antenna has a simple structure and a high degree of integration, making it easy to produce and manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of the printed dual-band broadband high-gain omnidirectional antenna of the present invention;

[0028] Figure 2 Schematic diagram of the PCB printed antenna structure of the present invention

[0029] Figure 3 Schematic diagram of the relationship between the planar printed conical dipole antenna and its metal loading plate of the present invention

[0030] Figure 4 Schematic diagram of the feed coaxial line of the present invention

[0031] Figure 5 Schematic diagram of the metal sleeve of the present invention

[0032] Figure 6 Schematic diagram of the antenna cover of the present invention

[0033] Figure 7 This is a diagram showing the composition of the planar conical dipole antenna radiation unit of the present invention.

[0034] Figure 8 The voltage standing wave ratio curve of the dual-band broadband resonance of the present invention;

[0035] Figure 9 is the gain curve of the dual-band broadband resonance of the present invention;

[0036] Figure 10 is the polarization isolation curve of the dual-band broadband resonance of the present invention;

[0037] Figure 11 The azimuth plane normalized radiation pattern of the antenna of the present invention at 2.4 GHz and 5.8 GHz.

[0038] Figure 12 The normalized elevation pattern of the antenna of the present invention at 2.4 GHz and 5.8 GHz. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] See also Figures 2 to 6 The present application provides a dual-band broadband high-gain printed omnidirectional antenna based on multi-mode resonance, including a PCB printed antenna 1, a loading metal sheet 2, a feeding coaxial line 3, a metal sleeve 4, and an antenna cover 5.

[0041] See also Figure 1 The PCB printed antenna 1, the loading metal sheet 2, and the feeding coaxial line 3 are located in a closed structure formed by the metal sleeve 4 and the antenna cover 5; the PCB printed antenna 1 is the main radiation part, and it and the loading metal sheet 2 are combined to form the radiator of the present application, and the radiation of the antenna of the present application is realized by feeding the feeding coaxial line 3; the feeding coaxial line 3 is installed at the root of the metal sleeve 4 and serves as the signal input / output interface of the antenna of the present application.

[0042] See also Figure 2 The PCB printed antenna 1 is a two-layer copper-clad structure of the PCB, 1-1 is the front copper-clad layer, 1-2 is the back copper-clad layer, 1-3 is the dielectric layer, 1-4 is the feed microstrip line, and the copper layers 1-1 and 1-2 constitute a binary H-shaped planar dipole antenna radiator, which is fed by the feed microstrip line 1-4. The antenna structure is attached to the dielectric layer 1-3; the antenna radiation band, impedance matching and gain optimization are achieved by adjusting the parameters such as the dipole width W1, dipole length L1 and dipole spacing D1 on the copper layers 1-1 and 1-2. Preferably, W1=17mm, L1=48mm and D1=72mm are selected;

[0043] See also Figure 3The loading metal sheet 2 is a semi-cylindrical metal loading sheet welded or bonded to the side of the planar printed conical dipole antenna of the PCB printed antenna 1. Each planar printed conical dipole antenna unit has four sides (both sides of the upper oscillator and both sides of the lower oscillator), and each side needs to be loaded with a metal sheet. The upper and lower metal sheets of each planar printed conical dipole antenna unit need to be symmetrical about the central horizontal line of the "H" shape to conform to the principle of the dipole antenna; by adjusting the width W2, length L2, and gap D2 of the metal sheet, the antenna radiation band, impedance matching, gain and other parameters are optimized. Preferably, W2=18mm, L2=36mm, and D2=10mm are selected;

[0044] See also Figure 4 The feeding coaxial line 3 is made of a 50-ohm coaxial line, one end of which is provided with a core wire 3-1 extending out of a shielding layer 3-2 and an insulating layer 3-3, and the other end is provided with a radio frequency connector 3-4; the extending core wire 3-1 of the feeding coaxial line 3 is L-shaped, so that it is convenient to pass through the feeding countersunk hole on the dielectric layer 1-3 of the PCB printed antenna 1 from the back and connect to the front copper clad layer 1-1 of the PCB printed antenna 1, and the shielding layer 3-2 is connected to the back copper clad layer 1-2; the radio frequency connector 3-4 passes through the metal sleeve 4 as the input / output interface of the antenna;

[0045] See also Figure 5 The metal sleeve 4 is a cylindrical metal cavity, the inner side of which is connected to the antenna cover 5 as its support; the bottom is connected to the RF connector flange of the feed coaxial line 3 to realize the output of the RF interface; the inner wall diameter D4 and inner wall length L4 of the metal sleeve 4 are adjusted according to the size of the selected antenna cover, preferably D4=D5+t5+0.2mm, L4=0.1*L5;

[0046] See also Figure 6 The antenna cover 5 is a glass fiber reinforced plastic circular tube structure, the outer side of which is installed on the inner side of the metal sleeve 4 to ensure waterproofness and wave transmission of the antenna. The inner diameter D5 is selected according to the width W1 of the oscillator of the PCB printed antenna 1, preferably D5 = W1 + 1mm. The wall thickness t5 of the antenna cover 5 needs to take into account both wave transmission and structural strength, preferably t5 = 1mm.

[0047] See also Figures 8 to 12 , which are the voltage standing wave ratio, gain curve, polarization isolation, azimuth and elevation plane radiation pattern results obtained by a dual-band broadband high-gain printed omnidirectional antenna based on multi-mode resonance designed in this application.

[0048] See also Figure 8This is the dual-frequency VSWR curve. The operating frequency band (VSWR is less than 2) of the design of this application example is 2.15~3.18GHz & 5.5~6.34GHz, and its relative impedance bandwidth is 38.6% & 14.1%; Figure 8 A comparison of the case with and without a metal sheet is also given. It is obvious that the metal sheet widens the low-frequency working bandwidth and stimulates high-order resonance, making the antenna have dual-band working characteristics and a wide bandwidth. Compared with the existing thin rod omnidirectional antenna, the antenna of this application has dual-band characteristics and the relative bandwidth of the main frequency is also wider. Figure 9 , the gain value of the embodiment of the present application is designed to be greater than 4dBi in the 2.28~2.54GHz frequency band, and greater than 5dBi in the 5.61~6.02GHz frequency band; Figure 9 A comparison between the cases with and without loaded metal sheets is also given. It is obvious that the loaded metal sheet widens the working bandwidth of the low-frequency gain and also obtains high gain characteristics in a wider bandwidth range at high frequencies. The antenna has wide bandwidth gain characteristics in both low-frequency and high-frequency bands.

[0049] The example design of the antenna in this application can be applied to the dual-band WIFI, dual-band drone communication, and dual-band drone interference frequency bands of 2.4~2.5GHz and 5.7~5.9GHz. The VSWR within this frequency band is less than 1.5, and the gain in the 2.4~2.5GHz band is greater than 4dBi, and the gain in the 5.7~5.9GHz band is greater than 5dBi.

[0050] See also Figure 10 This is the dual-frequency polarization isolation curve. The example of this application is designed in vertical polarization, and its polarization isolation is less than -50 dB in the operating frequency bands of 2.4~2.5GHz and 5.7~5.9GHz.

[0051] See also Figure 11 This is the horizontal plane radiation pattern of the dual-band antenna at 2.4GHz and 5.8GHz. It has excellent omnidirectional coverage characteristics in the horizontal plane, and the non-circularity is less than 1.5 dB, which is 0.5dB@2.4GHz and 1.3dB@5.8GHz respectively.

[0052] See also Figure 12 This is the vertical radiation pattern of the dual-band antenna at 2.4GHz and 5.8GHz. It has a wide beam coverage in the vertical plane, reaching 46°@2.4GHz and 26°@5.8GHz respectively.

Claims

1. A dual-band, broadband, high-gain printed omnidirectional antenna based on multi-mode resonance, characterized by: The invention comprises a PCB printed antenna (1), a loading metal sheet (2), a feeding coaxial line (3), a metal sleeve (4), and an antenna cover (5); wherein the PCB printed antenna (1) is located inside the antenna cover (5); the loading metal sheet (2) is located on the side of the PCB printed antenna (1) and is also located inside the antenna cover (5); the PCB printed antenna (1) radiation unit and the loading metal sheet (2) are connected to form the radiation part of the antenna, forming a structure of a two-element dipole antenna vertical array; the core wire of the feeding coaxial line (3) is electrically connected to one side of the PCB printed antenna (1); the sheath wire of the feeding coaxial line (3) is electrically connected to the PCB printed antenna (1); and the sheath wire of the feeding coaxial line (3) is electrically connected to the PCB printed antenna (1). The other side of the wire (1) is electrically connected to realize effective feeding of the antenna; the bottom of the feeding coaxial line (3) is connected to the metal sleeve (4) through a flange, and the radio frequency connector passes through the bottom of the metal sleeve (4) to serve as the output port of the antenna; the metal sleeve (4) is a cylindrical structure, the bottom of which is connected to the radio frequency connector flange of the feeding coaxial line (3); the antenna cover (5) is a glass fiber reinforced plastic circular tube, the bottom of which is inserted into the inner side of the metal sleeve (4) for fixing and passes through the PCB printed antenna (1), the loading metal sheet (2), and the feeding coaxial line (3) to form the antenna radiation component, and the antenna radiation component is covered in the antenna cover, thereby forming a complete antenna structure.

2. The dual-band, broadband, high-gain printed omnidirectional antenna based on multimode resonance according to claim 1, characterized in that: The PCB printed antenna (1) is a dielectric copper-clad structure, comprising a front copper-clad layer (1-1), a back copper-clad layer (1-2), and a dielectric (1-3), wherein the front copper-clad layer (1-1) and the back copper-clad layer (1-2) constitute a binary dipole antenna radiator; the antenna is frequency-band-adjusted by adjusting the oscillator width W1, the length L1-1 of the vertical part of the oscillator, the length L1-2 of the inclined part of the oscillator in the vertical direction, the bottom width W1-1 of the oscillator, and the oscillator spacing D1 on the front copper-clad layer (1-1) and the back copper-clad layer (1-2), wherein the adjustment range of W1, L1-1, L1-2, W1-1, and D1 is 1-1000 mm.

3. The dual-band, broadband, high-gain printed omnidirectional antenna based on multimode resonance according to claim 1, characterized in that: The width W2 of the loading metal sheet (2) is 1-1000mm, and the length L2 is 1-1000mm. The loading metal sheet (2) is fixed to the side of the PCB printed antenna (1) by welding or bonding. The number of the loading metal sheets (2) is equal to the number of the vibrators on the PCB printed antenna (1). The gap between the two loading metal sheets on the same pair of dipole units is D2-1, which has a value of 1-1000mm. The gap between adjacent loading metal sheets between the dipole units is D2-2, which has a value of 1-1000mm.

4. The dual-band, broadband, high-gain printed omnidirectional antenna based on multimode resonance according to claim 1, characterized in that: The feeding coaxial line (3) is a cable assembly consisting of a coaxial line and a radio frequency connector, wherein one end of the core wire (3-1) extends out of the shielding layer (3-2) and the other end is a radio frequency connector (3-3); the extended core wire (3-1) of the feeding coaxial line (3) is L-shaped and passes through the feeding countersunk hole on the medium (1-3) of the PCB printed antenna (1) from the back; the radio frequency connector (3-3) of the feeding coaxial line (3) is connected to the metal sleeve (4), thereby forming the output of the antenna.

5. The dual-band, broadband, high-gain printed omnidirectional antenna based on multi-mode resonance according to claim 1, characterized in that: The metal sleeve (4) is a metal cavity with a cylindrical structure, the inner side of which is connected to the antenna cover (5) as its support; the diameter of the metal sleeve is D4, the length is L4, and the thickness is t4. The bottom of the metal sleeve is connected to the radio frequency connector flange of the feed coaxial line (3) to realize the output of the radio frequency interface.

6. The dual-band, broadband, high-gain printed omnidirectional antenna based on multimode resonance according to claim 1, characterized by: The antenna cover (5) is a glass fiber reinforced plastic circular tube structure, which is located at the outermost side of the antenna and is used to protect the antenna radiator and play a role in fixing and waterproofing. The antenna cover (5) has a diameter of D5, a length of L5, and a thickness of t5. The antenna cover (5) is a wave-transmitting structure, and the electromagnetic waves radiated by the antenna pass through its side wall and radiate outward.

7. The dual-band, broadband, high-gain printed omnidirectional antenna based on multi-mode resonance according to claim 2, characterized by: The front copper clad layer (1-1) and the back copper clad layer (1-2) are combined to form two pairs of equal-amplitude and in-phase radiating units, namely, radiating unit one and radiating unit two; radiating unit one is composed of a front upper oscillator (1-1-1) of the front copper clad layer (1-1) and a back upper oscillator (1-2-1) of the back copper clad layer (1-2); radiating unit two is composed of a front lower oscillator (1-1-2) of the front copper clad layer (1-1) and a back lower oscillator (1-2-2) of the back copper clad layer; a front metal strip line (1-1-3) on the front copper clad layer (1-1) and a back metal strip line (1-2-3) on the back copper clad layer (1-2) feed radiating unit one and radiating unit two, and the lengths from the center point of the feed through hole (1-2-4) to the feeding positions of radiating unit one and radiating unit two are equal, that is, equal-amplitude and in-phase feeding is formed, thereby ensuring the synthesis efficiency of radiating unit one and radiating unit two.

8. The dual-band, broadband, high-gain printed omnidirectional antenna based on multi-mode resonance according to claim 7, characterized by: The loading metal sheet (2) is fixed on the side of the PCB printed antenna (1); the radiation unit 1 is connected to the upper loading sheet (2-1) of the loading metal sheet (2); the radiation unit 2 is connected to the lower loading sheet (2-2) of the loading metal sheet (2); the radiation unit 1 and the radiation unit 2 form a radiation unit with dual-band broadband characteristics through the connection with the loading metal sheet (2).

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