High gain multi-band stacked printed yagi antenna

Abstract

The application relates to a high-gain multi-frequency-band stacked printed Yagi antenna and belongs to the technical field of antennas. Multiple Yagi antenna units are printed on the same surface of a dielectric plate in a common-aperture form and are arranged in sequence according to the order from low to high frequencies. The adjacent antenna units are connected through a high-impedance structure. When an antenna of a certain frequency band is excited, the high-impedance structure can limit the current on the dipole from flowing to other units, thereby suppressing the coupling between the antennas and not affecting the normal work of other antenna units. The structure not only enables the frequency band and bandwidth of each Yagi antenna to be individually adjusted according to requirements, but also provides a feeding path for the coaxial feeder, so that the individual antenna units can work independently.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology and relates to a high-gain multi-band stacked printed Yagi antenna for use in communication, navigation, GPS and other systems. Background Technology

[0002] A Yagi antenna is an end-fire antenna consisting of an active dipole, a passive reflector (slightly longer than the active dipole), and several passive directors (slightly shorter than the active dipole) arranged in parallel. Due to its high gain and good directivity, it is often used in fields such as direction finding and navigation.

[0003] Common Yagi antennas are single-port fed. To increase the antenna's operating frequency range, methods such as adding parasitic stubs to the vibrator can be used. These methods produce very narrow bandwidths, each frequency band cannot be controlled independently, and they come at the cost of antenna gain. To improve antenna gain, multiple directors are often added above the vibrator, but this method greatly increases the antenna's profile height.

[0004] With the development of multi-band and miniaturized antennas, Yagi antennas need to be multiple antennas to work in multiple frequency bands. This not only increases the difficulty of decoupling, but also reduces the gain and greatly increases the space occupied by the antenna. Summary of the Invention

[0005] The technical problem to be solved by this invention is:

[0006] To avoid the decoupling and gain reduction problems caused by multiple frequency bands in Yagi antennas, this invention provides a high-gain multi-band stacked printed Yagi antenna.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] A high-gain multi-band stacked printed Yagi antenna is characterized by comprising a dielectric substrate and metal directors. Multiple frequency band antenna elements are printed on the dielectric substrate. Each antenna element includes a feed balun printed on the front side of the dielectric substrate and a radiating element printed on the back side. The feed balun and radiating elements are arranged from top to bottom according to frequency band height. Each radiating element includes a reflector, an active element, and a patch director arranged sequentially from bottom to top. A high-impedance structure is provided between the reflector and patch director of two adjacent frequency bands. Metal directors parallel to the dielectric substrate are provided on both sides of the dielectric substrate.

[0009] A further technical solution of the present invention: the metal guide is composed of n vertical and q horizontal metal sheets, where 1≤n≤20 and 1≤q≤20.

[0010] A further technical solution of the present invention: the material of the metal guide is aluminum.

[0011] A further technical solution of the present invention: the active dipole of the antenna element adopts the form of a half-wave dipole or a full-wave dipole.

[0012] A further technical solution of the present invention: the balun adopts an "L" shape.

[0013] A further technical solution of the present invention: the active element of the antenna unit is bent in the low frequency band, thereby reducing the lateral dimension of the antenna.

[0014] A further technical solution of the present invention: multiple patch directors can be set in the high-frequency band.

[0015] A further technical solution of the present invention: the dielectric substrate is made of FR4_epoxy material with a dielectric constant ε r =4.4.

[0016] A further technical solution of the present invention includes an antenna radome, which is located outside the metal director and can completely surround the antenna.

[0017] An application of a high-gain multi-band stacked printed Yagi antenna, characterized in that the front end is used for communication, navigation or GPS to transmit and receive signals.

[0018] The beneficial effects of this invention are as follows:

[0019] The present invention provides a high-gain multi-band stacked printed Yagi antenna, which uses a high-impedance patch to connect two adjacent antenna elements, so that the coaxial line of each element can pass through the ground plane along the patch and be connected to the power supply to achieve power feeding. The structure is simple, easy to install, and low in cost, and each antenna element can work independently.

[0020] To achieve multi-band and miniaturization, this invention employs an overlapping technique, printing multiple Yagi antenna elements on the same side of a dielectric substrate in a common-aperture configuration, arranged sequentially from low to high frequency. Adjacent antenna elements are connected via a high-impedance structure. When an antenna in a certain frequency band is excited, this high-impedance structure restricts the current flow from the vibrator to other elements, thereby suppressing coupling between antennas and ensuring the normal operation of other antenna elements. This structure not only allows the frequency band and bandwidth of each Yagi antenna to be individually adjusted as needed, but also provides a feeding path for the coaxial feed line, enabling each antenna element to operate independently.

[0021] To avoid increasing the antenna profile height, this invention provides directors composed of several horizontal and vertical rectangular metal plates on both sides of the dielectric substrate. This type of director improves the gain and also improves the antenna's standing wave ratio.

[0022] 1. Metal directors can improve antenna gain and reduce antenna standing wave ratio in some frequency bands without increasing the antenna profile height.

[0023] 2. Generally speaking, the closer the antennas are, the greater the coupling and the greater the interference between them. By adding a high-impedance structure, the coupling between closely arranged antenna elements is greatly reduced, allowing each frequency band element to operate independently;

[0024] 3. Common multi-band Yagi antennas form new resonant points by adding parasitic structures, but the bandwidth of the frequency band where the resonant point is located is very narrow. However, in this invention, each frequency band is realized by a reflector-active oscillator-director structure, which has a wider bandwidth.

[0025] 4. The Yagi antenna in this invention can be individually fed and controlled for each frequency band. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1 This is a schematic diagram of the overall structure of the Yagi antenna of the present invention;

[0028] Figure 2 This is a front view of the Yagi antenna of the present invention (with the metal sheet removed);

[0029] Figure 3 This is a rear view of the Yagi antenna of the present invention (with the metal sheet removed);

[0030] Figure 4 This is a three-dimensional view of the metal sheet (connected to the floor) of the present invention;

[0031] Figure 5 This refers to the standing wave in the 900MHz band of this invention;

[0032] Figure 6 This refers to the standing wave in the 1.575GHz band of this invention;

[0033] Figure 7 This refers to the standing wave in the 2.4GHz band of this invention;

[0034] Figure 8 This refers to the standing wave in the 5.8GHz band of this invention;

[0035] Figure 9 This refers to the gain in the 900MHz band of this invention;

[0036] Figure 10 This refers to the gain in the 1.575GHz band of this invention;

[0037] Figure 11 This refers to the gain in the 2.4GHz band of this invention;

[0038] Figure 12 This refers to the gain in the 5.8GHz band of this invention;

[0039] Figure 13 The effect of the presence or absence of a metal director on antenna gain: (a) 900MHz band; (b) 1.575GHz band; (c) 2.4GHz band; (d) 5.8GHz band;

[0040] Figure 14 The effect of the presence or absence of a metal director on antenna standing wave ratio: (a) 900MHz band; (b) 1.575GHz band; (c) 2.4GHz band; (d) 5.8GHz band.

[0041] Wherein: 1-Dielectric radome; 2-Dielectric substrate; 3-900MHz feed balun; 4-1.575GHz antenna element feed balun; 5-2.4GHz antenna element feed balun; 6-5.8GHz antenna element feed balun; 7-900MHz antenna element reflector; 8-900MHz antenna element active element; 9-900MHz antenna element director; 10-1.575GHz antenna element reflector; 11-1.575GHz antenna element active element... Active element; 12-1.575GHz antenna element director; 13-2.4GHz antenna element reflector; 14-2.4GHz active element antenna element; 15-2.4GHz antenna element director; 16-5.8GHz antenna element reflector; 17-5.8GHz active element antenna element; 18-5.8GHz antenna element director; 19-Feed coaxial line; 20-High impedance structure; 21-Metal director; 22-Metal ground plane; 23-Round hole in the ground plane. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0043] This invention provides a high-gain multi-band stacked printed Yagi antenna, operating in the frequencies of 840-930MHz, 1.52-1.67GHz, 2.4-2.5GHz, and 5.7-5.9GHz, covering four frequency bands. Employing a common aperture design, the antennas are arranged from bottom to top on a dielectric substrate using overlapping technology, with center frequencies of 900MHz, 1.575GHz, 2.4GHz, and 5.8GHz. Due to the global universality of the ISM band, this antenna can be widely used in various wireless products. The antenna elements for each frequency band are printed in a stacked manner on the same surface of the dielectric substrate. By adding a high-impedance patch between the reflectors and directors of adjacent antenna elements, the coaxial cable can pass through the patch and connect to the power supply, achieving simple and efficient feeding of multiple antenna elements while ensuring independent operation of each element. This solves the problem of large space occupation in traditional multi-band antennas.

[0044] like Figure 1-4 As shown, the present invention includes a dielectric substrate 2, a metal director 21, and a metal ground plane 22. The dielectric substrate 2 and the metal ground plane 22 are placed vertically. Metal sheets parallel to the dielectric substrate 2 are placed on both sides of the dielectric substrate 2. The metal sheets are connected to the metal ground plane 22, i.e., the metal director 21.

[0045] Specifically, the dielectric substrate 2 uses FR4_epoxy (dielectric constant ε) r =4.4) The plate material is rectangular in shape. The dielectric constant, shape and thickness of the dielectric substrate 2 can be selected according to the actual installation strength requirements, antenna placement and cost considerations.

[0046] Feed baluns and radiating elements are printed on both sides of the dielectric substrate 2, with each feed balun and antenna element forming an antenna element. The feed baluns include four frequency bands: a 900MHz feed balun 3, a 1.575GHz antenna element feed balun 4, a 2.4GHz antenna element feed balun 5, and a 5.8GHz antenna element feed balun 6, arranged sequentially from low to high frequency, corresponding to the bottom-up arrangement of the dielectric substrate 2. The radiating elements cover 900MHz, 1.575GHz, 2.4GHz, and 5.8GHz. The 900MHz radiating element includes a 900MHz antenna element reflector 7, a 900MHz antenna element active element 8, and a 900MHz antenna element director 9, arranged from bottom to top. The 1.575GHz radiating element includes a 1.575GHz antenna element active element 8, and a 1.575GHz antenna element director 9. The 1.575GHz antenna element reflector 10, the 1.575GHz antenna element active element 11, and the 1.575GHz antenna element director 12 are arranged from bottom to top; the 2.4GHz radiating element includes the 2.4GHz antenna element reflector 13, the 2.4GHz antenna element active element 14, and the 2.4GHz antenna element director 15, arranged from bottom to top; the 5.8GHz radiating element includes the 5.8GHz antenna element reflector 16, the 5.8GHz antenna element active element 17, and the 5.8GHz antenna element director 18, arranged from bottom to top; each antenna element in each frequency band has a small hole corresponding to the feed balun for introducing the feed coaxial line 19 to connect with the feed balun.

[0047] Each adjacent antenna element is connected using a high-impedance structure, such as... Figure 3 As shown by reference numeral 20 in the attached figure, a high-impedance structure is located between the director of the low-frequency antenna element and the reflector of the high-frequency antenna element. Specifically, a high-impedance structure is provided between the 900MHz antenna element director 9 and the 1.575GHz antenna element reflector 10, between the 1.575GHz antenna element director 12 and the 2.4GHz antenna element reflector 13, and between the 2.4GHz antenna element director 15 and the 5.8GHz antenna element reflector 16. When an antenna in a certain frequency band is excited, this high-impedance structure can suppress the current flowing from the vibrator to other elements, thereby reducing the coupling between elements and enabling each element to operate independently.

[0048] Specifically, the antenna element is a half-wave dipole, and the form of the active element (e.g., half-wave dipole, full-wave dipole, etc.) can be selected according to actual needs.

[0049] Specifically, the power supply balun adopts an approximately "L" shape, and its specific shape and location are as follows: Figure 2 As shown. The shape and position of the power supply balun can be adjusted according to the actual situation.

[0050] Specifically, the metal guide 21 is made of metal (e.g., aluminum), and its thickness can be selected according to actual conditions, preferably the same as the thickness of the metal floor 22. The metal guide 21 is composed of two horizontal and one vertical rectangular metal plates. In fact, the number and combination of metal plates are not limited and can be selected according to actual needs.

[0051] Preferably, the metal sheet and metal ground 22 are cut out in their entirety during processing and then bent. Antennas processed in this way have better performance than those made by cutting the metal sheet and metal ground 22 separately and then welding them together.

[0052] In order to provide electromagnetic isolation and protection for the antenna, a dielectric antenna cover 1 is provided outside the antenna. The dielectric antenna cover 1 is rectangular in shape, can completely cover the antenna, and maintains a certain distance from the antenna.

[0053] The invention also includes four feeding coaxial lines 19, corresponding to four frequency bands (900MHz, 1.575GHz, 2.4GHz, and 5.8GHz). The lower end of the feeding coaxial line 19 passes through a circular hole 23 in the metal ground plane 22 along the longitudinal direction of the antenna vibrator and is connected to the power supply; the upper inner core passes from the back side of the dielectric substrate 2 to the front side and is soldered to the balun. When the power is turned on, the balun at the corresponding frequency will excite the vibrator and radiate electromagnetic waves.

[0054] Specifically, the most basic Yagi antenna consists of an active element (approximately half a wavelength in length), a reflector (slightly longer than the active element), and a director (slightly shorter than the active element). The reflector and director convert the original bidirectional radiation into unidirectional radiation, thereby increasing the antenna gain. Depending on the gain requirements, the number of directors can be appropriately increased. For example, the antenna element corresponding to the 5.7-5.9 GHz band in this invention contains three directors. Figure 3 Reference numeral 18 in the attached figure. Furthermore, this type of antenna, the Yagi antenna, operates independently without interference between its various frequency bands.

[0055] In particular, for the 900MHz antenna element, because the vibrator is too long, it is bent backward to reduce the overall lateral size, thus achieving a miniaturized antenna design.

[0056] like Figures 5-8 The standing wave ratio (SWR) for each frequency band is between 2.25 and 1.05.

[0057] like Figures 9-12 The gain for each frequency band is between 7 and 9 dB.

[0058] This invention has been applied to a company's handheld anti-drone device, serving a directional function. The antenna size matches the device's internal dimensions, making manufacturing simple and installation secure. The antenna is small and lightweight, minimizing physical exertion on the user. Actual testing has shown that the device using this invention can successfully interfere with a DJI Mavic 2 drone at a distance of 1.2 km from the user.

[0059] The features of this invention are as follows:

[0060] 1. Yagi antennas in the m-band (2≤m) are arranged using a common aperture configuration and overlapping techniques;

[0061] 2. Add a high-impedance patch between the reflector and director of adjacent antenna elements to reduce the coupling between antennas, so that the elements of each frequency band can work independently, and at the same time, provide a feeding path for the coaxial line.

[0062] 3. Use metal sheets containing n vertical and q horizontal (1≤n≤20, 1≤q≤20) structures to improve antenna gain and reduce standing waves of antenna elements in some frequency bands.

[0063] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A high-gain multi-band stacked printed Yagi antenna, characterized in that... The device includes a dielectric substrate, metal directors, and a metal ground plane. The dielectric substrate and the metal ground plane are placed vertically. Multiple frequency band antenna elements are printed on the dielectric substrate. Each antenna element includes a feed balun printed on the front side of the dielectric substrate and a radiating element printed on the back side. The feed balun and the radiating elements are arranged from top to bottom according to the frequency band, where "from top to bottom" refers to the vertical direction from away from the metal ground plane to close to it. Each radiating element includes a reflector, an active element, and a patch director arranged sequentially from bottom to top. In two adjacent frequency bands, a high-impedance structure is provided between the patch director of the lower frequency band antenna element and the reflector of the higher frequency band antenna element. Metal directors parallel to the dielectric substrate are provided on both sides of the front and back sides of the dielectric substrate, and the metal directors are connected to the metal ground plane.

2. The high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... The metal guide is composed of n metal plates perpendicular to the metal floor and q metal plates parallel to the metal floor, where 1≤n≤20 and 1≤q≤20.

3. A high-gain multi-band stacked printed Yagi antenna according to claim 2, characterized in that... The metal guide is made of aluminum.

4. A high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... The active dipole of the antenna element is in the form of a half-wave dipole or a full-wave dipole.

5. A high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... The baron is L-shaped.

6. A high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... The active element of the antenna unit is bent in the low-frequency band, which reduces the lateral dimension of the antenna.

7. A high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... Multiple surface mount directors are configured for the high-frequency band.

8. A high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... The dielectric substrate is made of FR4_epoxy material with a dielectric constant of [missing value]. .

9. A high-gain multi-band stacked printed Yagi antenna according to claim 1, characterized in that... It also includes an antenna radome, which is located outside the metal director and can completely surround the antenna.

10. An application of a high-gain multi-band stacked printed Yagi antenna, characterized in that, The Yagi antenna as described in any one of claims 1-9 is used for transmitting and receiving signals at the front end of a communication, navigation, or positioning system.

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