Microstrip patch antenna

Abstract

The invention discloses a microstrip patch antenna, relates to the technical field of antennas, solves the problems of low gain and complex antenna lamination of a microstrip patch antenna provided in the prior art, and adopts the technical scheme that the microstrip patch antenna comprises a split ring and radiation patches symmetrically arranged on the left side and the right side of the split ring; a microstrip line feed port is formed in the left side of the lower part of the split ring; the radiation patches are connected through a microstrip line with the length of L, and the microstrip line with the length of L is used for adjusting the phase difference of electromagnetic waves radiated by the radiation patches on the left side and the right side, so that energy radiated by the radiation patches on the left side and the right side is superposed in a far field to obtain antenna gain; the microstrip line feed port is provided with a matching branch knot.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and more specifically, to a microstrip patch antenna. Background Art

[0002] Microstrip patch antennas are widely used in microwave communication systems because of their low cost and low profile.

[0003] Common microstrip patch antennas have the disadvantages of low gain and narrow bandwidth. Currently, the bandwidth of microstrip patch antennas is increased by coupling the stripline gap and exciting the parasitic radiation patch. However, the antenna designed in this way has the disadvantage of complex lamination. When used in phased array antennas, it will lead to complex antenna board lamination, which is not conducive to production. Summary of the invention

[0004] The object of the present invention is to provide a microstrip patch antenna to solve the problems of narrow band, low gain and complex antenna stacking of the microstrip patch antenna provided by the prior art.

[0005] The present application provides a microstrip patch antenna, which is printed on a metal layer of a double-sided PCB board. The microstrip patch antenna includes an open ring and radiation patches symmetrically arranged on the left and right sides of the open ring, and a microstrip line feeding port is arranged at the left position below the open ring;

[0006] The radiating patches are connected by a microstrip line with a length of L, and the microstrip line with a length of L is used to adjust the phase difference of the electromagnetic waves radiated by the radiating patches on the left and right sides, so that the energy radiated by the radiating patches on the left and right sides is superimposed in the far field to obtain antenna gain;

[0007] A matching branch is arranged on the microstrip line feeding port.

[0008] In one implementation, a plurality of slots are provided on the two radiation patches, and a high-order mode is introduced into each slot; wherein the slots between the radiation patches are symmetrically arranged.

[0009] In one implementation, the split ring is folded in a vertical direction.

[0010] In one implementation, a microstrip patch antenna with an open ring folded is applied to a phased array antenna.

[0011] In one implementation, the radiation patch on the left side of the split ring is mirror-flipped to achieve phase modulation.

[0012] In one implementation, the radiation patch on the right side of the split ring is mirror-flipped to achieve phase modulation.

[0013] In one implementation, the microstrip line feeding port is adjusted from the left side of the open ring to the middle position below the open ring.

[0014] In one implementation, the open ring is in a rectangular shape.

[0015] In one implementation, the radiation patch is rectangular in shape.

[0016] In one implementation, the microstrip patch antenna operates in the Ka band.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. An embodiment of the present invention provides a microstrip patch antenna, which includes an open ring and radiating patches symmetrically arranged on the left and right sides of the open ring, and a microstrip line feeding port is arranged on the left side below the open ring; the radiating patches are connected by a microstrip line with a length of L, and the microstrip line with a length of L is used to adjust the phase difference of the electromagnetic waves radiated by the radiating patches on the left and right sides, so that the energy radiated by the radiating patches on the left and right sides is superimposed in the far field to obtain a higher antenna gain and narrowband.

[0019] 2. An embodiment of the present invention provides a microstrip patch antenna, which folds the open ring and can effectively reduce the length of the antenna in the vertical direction, thereby avoiding the disadvantage of complex lamination caused by the use of stripline coupling gaps to excite parasitic radiation patches. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0021] Figure 1 A first structural schematic diagram of a microstrip patch antenna provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of a standing wave at the first port of a microstrip patch antenna provided in an embodiment of the present application;

[0023] Figure 3 A first radiation pattern of the microstrip patch antenna provided in an embodiment of the present application;

[0024] Figure 4 A second structural schematic diagram of a microstrip patch antenna provided in an embodiment of the present application;

[0025] Figure 5 A schematic diagram of a standing wave at the second port of the microstrip patch antenna provided in an embodiment of the present application;

[0026] Figure 6A second radiation pattern of the microstrip patch antenna provided in an embodiment of the present application;

[0027] Figure 7 A third structural schematic diagram of a microstrip patch antenna provided in an embodiment of the present application;

[0028] Figure 8 A schematic diagram of a third port standing wave of a microstrip patch antenna provided in an embodiment of the present application;

[0029] Fig. 9 A third radiation pattern (35 GHz) of a microstrip patch antenna provided in an embodiment of the present application;

[0030] Fig.10 A fourth structural schematic diagram of a microstrip patch antenna provided in an embodiment of the present application;

[0031] Fig.11 A schematic diagram of a fourth port standing wave of a microstrip patch antenna provided in an embodiment of the present application;

[0032] Fig.12 This is a fourth radiation pattern (35 GHz) of a microstrip patch antenna provided in an embodiment of the present application.

[0033] Marks and corresponding parts names in the attached drawings:

[0034] 1. Open ring; 2. Radiating patch; 3. Matching branches. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0036] It should be noted that the terms "include" or "may include" used in various embodiments of the present application indicate the presence of the function, operation or element applied for, and do not limit the addition of one or more functions, operations or elements. In addition, as used in various embodiments of the present application, the terms "include", "have" and their cognates are only intended to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items.

[0037] In various embodiments of the present application, the expression "or" or "at least one of B or / and C" includes any combination or all combinations of the words listed at the same time. For example, the expression "B or C" or "at least one of B or / and C" may include B, may include C, or may include both B and C.

[0038] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0040] Please refer to Figure 1 , Figure 1 A first structural diagram of a microstrip patch antenna provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the microstrip patch antenna is printed on the metal layer of the double-sided PCB board, and the microstrip patch antenna operates in the Ka band. The microstrip patch antenna includes an open ring 1 and radiating patches 2 symmetrically arranged on the left and right sides of the open ring 1, and a microstrip line feeding port is arranged on the left side below the open ring 1; the radiating patches 2 are connected by a microstrip line with a length of L, and the microstrip line with a length of L is used to adjust the phase difference of the electromagnetic waves radiated by the radiating patches 2 on the left and right sides, so that the energy radiated by the radiating patches 2 on the left and right sides is superimposed in the far field to obtain the antenna gain; a matching branch 3 is arranged on the microstrip line feeding port.

[0041] Specifically, the microstrip patch antenna is the most basic microstrip antenna, which consists of a dielectric substrate, a ground plane, and a conductive sheet or microstrip line. The thickness of the dielectric substrate is much smaller than the wavelength. The metal thin layer at the bottom of the substrate is connected to the ground plane, and the metal thin layer with a specific shape is made on the front through a photolithography process as a radiator. The working principle of the microstrip patch antenna is to use a conductive material to cover the surface of the dielectric to form a strip structure, and then connect it with other circuit elements to realize the transmission and reception of electromagnetic waves. Usually, a microstrip line or coaxial line is used for feeding, so that the radio frequency electromagnetic field is excited between the conductor radiation patch and the ground plane, and radiates outward through the gap between the radiation patch and the surrounding ground plane. The microstrip patch antenna has the following characteristics and advantages, namely small size and light weight: the microstrip patch antenna has the characteristics of one-dimensional miniaturization, which can greatly reduce the size and weight of the antenna. Easy to integrate: due to the simple structure of the microstrip patch antenna, it is easy to integrate with other circuit elements, so it is widely used in integrated circuits and microwave circuits. Low cost: The processing of microstrip patch antennas mainly relies on mature photolithography technology, the development of integration technology and plate making technology, making the production of microstrip antennas convenient and simple, and low-cost, especially in large-scale production, which not only saves costs, but also has high consistency between antennas. Diversified performance: By designing radiating patch units of different shapes, or selecting appropriate unit arrays, side-fire arrays, end-fire arrays, various polarizations, point scanning microstrip phased arrays, etc. can be realized.

[0042] Figure 1 The first structural schematic diagram of a microstrip patch antenna provided in the embodiment is printed on a double-sided PCB board, the top layer includes a feeder in the form of a microstrip line and an antenna radiation patch made of metal material, the bottom layer is a complete metal ground, and between the metal ground and the radiation layer is a dielectric substrate with a thickness of h and a length and width of P. The dielectric substrate involved in this embodiment is M6 with a thickness of 0.508mm, and the size of the dielectric substrate is 16*16mm. The antenna includes an open ring 1 and two radiation patches 2 symmetrical about the center of the antenna, and the shapes of the open ring 1 and the radiation patch 2 are both rectangular.

[0043] The radiation patch 2 is a metal strip or sheet in the microstrip patch antenna that is responsible for capturing and radiating electromagnetic waves. It is usually printed on the surface of the dielectric substrate and forms a capacitive coupling with the ground plane, thereby providing the necessary electromagnetic field distribution.

[0044] The microstrip line feed port is located on the left side of the open ring 1. Specifically, the microstrip line feed port refers to a structure that uses a microstrip line to transmit the radio frequency signal to the antenna radiation part. The microstrip line is a popular planar transmission line that is easy to process and integrate, and can adjust its shape arbitrarily to form a slot-type, step-type or gradient-type coupling structure. The main function of the microstrip line feed port is to achieve efficient transmission and impedance matching of radio frequency signals, ensuring that the antenna can work normally and radiate the expected electromagnetic waves. The microstrip line feed port adopts direct feeding or coaxial feeding. This embodiment adopts direct feeding, that is, the microstrip line is directly connected to the radiation patch for feeding. This method is also called side feeding. The position of the feeding point can be selected as needed, usually located at the center of one side of the radiation patch or close to one side. When designing the microstrip line feed port, the following factors need to be considered: Impedance matching: The impedance of the antenna is usually not matched with the commonly used 50 ohm impedance, so it is necessary to make appropriate matching between the input feed line and the antenna. Impedance matching can be achieved by selecting an appropriate feeding point position, using an impedance matching transformer, etc. Feed point location: The location of the feed point has a great influence on the performance of the antenna. Generally, the feed point should be selected near the location with the largest electric field and the largest current to improve the feeding efficiency and radiation power. At the same time, factors such as the symmetry and frequency characteristics of the antenna need to be considered to determine the optimal feed point location. Microstrip line width: The width of the microstrip line will affect its transmission performance and radiation performance. It is usually required that the microstrip line should not be too wide. Generally, the width of the microstrip line is much smaller than one wavelength to avoid unnecessary radiation and interference.

[0045] In the design of microstrip antennas, there is usually a mismatch between the impedance of the antenna and the commonly used 50 ohm impedance. This mismatch will cause reflection and loss of the RF signal during transmission, reducing the radiation efficiency and performance of the antenna. Therefore, the purpose of setting a matching branch on the microstrip line feed port is to achieve impedance matching, thereby improving the performance of the antenna. When designing matching branches, the following factors need to be considered: Size and position: The size and position of the matching branch have a great influence on the impedance matching effect. It is usually necessary to determine the size and position of the matching branch according to the specific size, operating frequency and impedance requirements of the antenna. Material selection: The material of the matching branch should have good conductivity and stability to ensure that it can work stably for a long time. Processing accuracy: The processing accuracy of the matching branch has a great influence on its performance. Therefore, the processing accuracy needs to be strictly controlled during the processing to ensure that the size and shape of the matching branch meet the design requirements.

[0046] In actual applications, there are various forms and types of matching branches, such as single-branch matching network, multi-branch matching network, balun matching, etc. These matching branches can be selected and designed according to specific application scenarios and antenna design requirements, and this embodiment does not make specific limitations.

[0047] The distance between the two radiating patches 2 is L. The microstrip line with a length of L is used to adjust the phase difference of the electromagnetic waves radiated by the two radiating patches 2, so that the energy radiated by the two radiating patches 2 can be superimposed in the far field to obtain a larger antenna gain. In order to achieve a good match between the antenna and the microstrip line, Figure 1 Add matching branch 3 at the position shown. Figure 2 The port S parameters of the antenna are shown, which satisfy S11≤-10dB in the frequency band of 33.85-36.48GHz. Figure 3 The figure shows the simulation result of the radiation pattern of the antenna at 35 GHz. According to the simulation result, the normal gain of the antenna is 10.2 dB.

[0048] In some embodiments, Figure 4 As shown, Figure 4 A second structural diagram of a microstrip patch antenna provided in an embodiment of the present application is shown. Figure 4 In the embodiment, a plurality of gaps are provided on two radiation patches 2, and a high-order mode is introduced into each gap; wherein the gaps between the radiation patches 2 are symmetrically provided.

[0049] Specifically, in order to obtain a higher antenna gain, the present invention proposes Figure 4 The antenna type shown, in Figure 1 On the basis of the antenna shown in FIG. 1 , multiple slots are opened on the radiation patch 2, and a high-order mode is introduced into each slot, thereby improving the gain and expanding the matching bandwidth. Figure 4 As shown, the slot is a rectangular shape. It can also be another shape under the condition of satisfying the same antenna gain performance. This embodiment does not make specific limitations. Secondly, the shape of the radiating patch can be a variety of regular shapes such as rectangular, circular, triangular, etc., or it can be an irregular shape to meet specific application requirements. Changes in shape will affect the radiation characteristics and radiation pattern of the antenna. For example, a rectangular radiating patch antenna is one of the most common types, and its radiation direction is usually upward and has a high radiation gain.

[0050] Secondly, higher-order modes are relative to the fundamental mode. The fundamental mode is a basic mode when electromagnetic waves propagate in a waveguide or optical fiber, while higher-order modes are all modes except the fundamental mode.

[0051] Figure 1 The antenna shown is Figure 4 The antennas shown have the same radiating aperture. Figure 5 Shown Figure 4 The simulation results of the port S parameters of the antenna shown in the figure show that the antenna of this type meets S11≤-10dB in the frequency band of 33.61-36.84GHz. Figure 6The figure shows the simulated radiation pattern of the antenna at 35GHz. According to the simulation results, Figure 4 The antenna shown has a normal gain of 10.79 dB at 35 GHz. Figure 1 The antenna gain is shown to be improved by 0.59 dB.

[0052] In some embodiments, Figure 7 As shown, Figure 7 A third structural schematic diagram of a microstrip patch antenna provided in an embodiment of the present application, Figure 7 In the process, the open ring 1 is folded in the vertical direction.

[0053] Specifically, Figure 1 The antenna shown is Figure 4 The size of the antenna shown is relatively large. When used in an active phased array antenna, the distance between antenna units is limited, and grating lobes are likely to appear. In order to make the high-gain antenna suitable for scanning phased arrays, this embodiment proposes Figure 7 The folded antenna shown in the figure. In this embodiment, the open ring 1 is folded, which can effectively reduce the length of the antenna in the vertical direction. Figure 7 The size of the antenna shown is 4.5 mm*12 mm. The microstrip radiation patch 2 antenna after folding the open ring 1 is applied to the phased array antenna. At 35 GHz, 45° scanning in the pitch direction can be achieved without grating lobes. Figure 8 Shown Figure 7 The simulation results of the port S parameters of the antenna shown in the figure show that the antenna meets S11≤-10dB in the frequency band of 34.22-37.49. Fig. 9 The figure shows the radiation pattern of the antenna at 35 GHz. According to the simulation results, the normal gain is 9 dB.

[0054] In some embodiments, Fig.10 As shown, Fig.10 A fourth structural diagram of a microstrip patch antenna provided in an embodiment of the present application, Fig.10 In the embodiment, the radiation patch 2 on the left side of the open ring 1 is mirror-flipped to achieve phase modulation; or, the radiation patch 2 on the right side of the open ring 1 is mirror-flipped to achieve phase modulation.

[0055] Specifically, Fig.10 The antenna shown is Figure 7 The deformation of the antenna shown (the radiating patch on the right is flipped). Figure 1 , Figure 4 , Figure 7All three antennas need to adjust the width L of the open ring 1 to achieve phase modulation of the two radiating patches 2, so as to maximize the gain. The size of the open ring 1 is L, which is related to the wavelength and is generally half a wavelength. Therefore, the size of the radiating patch 2 antenna in the horizontal direction is limited. In order to achieve miniaturization of the antenna, this embodiment proposes Fig.10 The antenna scheme shown in the figure can achieve phase modulation by adjusting the direction of the radiation patch 2 on the right.

[0056] In one embodiment, the microstrip line feeding port is adjusted from the left side of the open ring 1 to the middle position below the open ring 1. That is, the feeding port is introduced from the middle position below the open ring 1, and the position of the microstrip feed line relative to the two radiation patches 2 is adjusted to maximize the gain of the antenna in the normal direction. Fig.10 The size of the antenna shown is 5*9mm. Fig.11 for Fig.10 The simulation results of the port curve of the antenna shown in FIG. 1 show that the antenna meets S11<-10dB in the frequency band of 33.3-36.9GHz. Fig.12 The figure shows the simulated radiation pattern of the antenna at 35 GHz. According to the simulation results, the normal gain of the antenna at 35 GHz is 8.45 dB.

[0057] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A microstrip patch antenna, wherein the microstrip patch antenna is printed on a metal layer of a double-sided PCB board, characterized in that: The microstrip patch antenna comprises an open ring and radiation patches symmetrically arranged on the left and right sides of the open ring, and a microstrip line feeding port is arranged at the left position below the open ring; The radiating patches are connected by a microstrip line with a length of L, and the microstrip line with a length of L is used to adjust the phase difference of the electromagnetic waves radiated by the radiating patches on the left and right sides, so that the energy radiated by the radiating patches on the left and right sides is superimposed in the far field to obtain antenna gain; A matching branch is arranged on the microstrip line feeding port.

2. A microstrip patch antenna according to claim 1, characterized in that: A plurality of gaps are provided on the two radiation patches, and a high-order mode is introduced into each gap; wherein the gaps between the radiation patches are symmetrically arranged.

3. A microstrip patch antenna according to claim 2, characterized in that: Fold the split ring vertically.

4. A microstrip patch antenna according to claim 3, characterized in that: The split-ring folded microstrip patch antenna is applied to phased array antenna.

5. The microstrip patch antenna according to claim 3, characterized in that: The radiating patch on the left side of the split ring is mirrored to achieve phase modulation.

6. The microstrip patch antenna according to claim 3, characterized in that: The radiating patch on the right side of the split ring is mirrored to achieve phase modulation.

7. A microstrip patch antenna according to any one of claims 5 to 6, characterized in that: The microstrip line feeding port is adjusted from the left side of the open ring to the middle position below the open ring.

8. The microstrip patch antenna according to claim 1, characterized in that: The shape of the open ring is rectangular.

9. The microstrip patch antenna according to claim 1, characterized in that: The radiation patch is in the shape of a rectangle.

10. The microstrip patch antenna according to claim 1, characterized in that: The microstrip patch antenna operates in the Ka frequency band.

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