Pavilion-shaped microstrip antenna

Abstract

The pavilion-shaped microstrip antenna comprises a dielectric substrate, a radiation patch structure and a grounding plate, the radiation patch structure and the grounding plate are arranged on the same side of the dielectric substrate, and the dielectric substrate is only provided with a conductive layer on one side where the radiation patch structure is arranged. According to the special design, the radiation patch structure comprises a central rectangular conduction band, a triangular conduction band connected to the top of the central rectangular conduction band and bent conductive arms symmetrically distributed on the two sides of the central rectangular conduction band, and each bent conductive arm is formed by continuously bending multiple sections of conduction bands; the grounding plate and the radiation patch structure are arranged in a coplanar manner, and the grounding plate comprises a central grounding part located below the central rectangular conduction band and side grounding parts symmetrically arranged on the two sides of the central grounding part; and the conduction band section on the outermost side of the bent conductive arm and the corresponding side grounding part are arranged in parallel at an interval.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a pavilion-shaped microstrip antenna. Background Art

[0002] Microstrip antennas are a new type of antenna that gradually developed in the mid-to-late 20th century. Due to their advantages such as small size, low cost, strong structure and simple process, as well as the convenience of dual-band operation, they are widely used in communications, broadcasting, aerospace and other fields.

[0003] Compared to traditional antennas, microstrip antennas offer advantages such as small size, low profile, ease of integration, low cost, conformal conformity with the carrier, and excellent performance. Furthermore, aside from requiring lead holes at the feed point, they do not disrupt the carrier's mechanical structure, making them particularly advantageous for high-speed aircraft. With the continuous development of the mobile communications industry, communication equipment is becoming increasingly miniaturized and intelligent, placing increasing demands on the size, integration, and operating frequency of microstrip antennas. Microstrip antennas can be integrated with active components and circuits into a single component, making them suitable for mass production, simplifying overall device fabrication and commissioning, and significantly reducing costs.

[0004] Related prior art documents include: Reference 1: Denlinger. EJ “Radiation from Microstrip Resonators.” IEEE Transactions on Microwave Theory and Techniques, 1969, 17(4): 235-236. In 1969, he published research results on the radiation of rectangular and circular microstrip resonators. He believed that the radiation generated by rectangular and circular microstrip resonators was caused by the discontinuity of the conductor sheet, and that the radiation would increase with the thickness of the dielectric substrate and decrease with the increase of the dielectric constant of the dielectric substrate. The goal of his work was to reduce the radiation in order to achieve the purpose of improving the quality factor (Q) of the resonator.

[0005] Reference 2: Song Yinsuo, "Engineering Design of Microstrip Grid Antenna Array," Aviation Weaponry, 1985, (03): 1-4. Based on the analysis and experiment of the working principle of the microstrip grid antenna array, a simple engineering design method for determining the microstrip grid size was proposed. Once the operating frequency and dielectric material are given, the grid size can be determined quickly and accurately.

[0006] Reference 3: Luo Y, Chu Q X. “Oriental Crown-Shaped Differentially Fed Dual-Polarized Multidipole Antenna,” IEEE Transactonson Antennas and Propagation, 2015, 63(11): 4678-4685. A differentially fed dual-polarized multipole antenna is proposed, in which two pairs of long dipoles and two pairs of short dipoles are printed on an oriental crown-shaped substrate. By rationally designing the position of the dipoles, a stable radiation pattern is achieved in the horizontal plane within a relative bandwidth of 45%. Due to the symmetry of the antenna, the isolation between its differential ports is theoretically infinite. The proposed antenna achieves broadband impedance matching and a stable radiation pattern. The half-power beamwidth in the horizontal plane maintains an average value of 65 ◦ , the antenna looks like the famous Oriental Crown China Pavilion building at the World Expo held in Shanghai.

[0007] Reference 4: Feng BT, et al. “A Compact Vehicle-Mounted Garden-Themed Artistic Antenna with Isolation Improvement for 2G / 3GLTE / 5G Sub-6-GHz / WiFi / Bluetooth Communications,” IEEE Transactions on Vehicular Technology, 2023, 72(4):4851-4862. A multi-band vehicle-mounted garden-themed artistic antenna with isolation improvement for 2G / 3G / LTE / 5Gsub6 GHz / WiFi / Bluetooth is proposed. The antenna is mainly composed of three printed circuit board substrates. In order to obtain a good isolation level, two pavilion-shaped 4G band (including 2G / 3G / LTE band) patches and two tree-shaped 5G band (including 5G sub-6GHz band) patches are placed diagonally on the four corners of the top substrate, while another two tree-shaped 5G band patches and a peach-shaped WiFi band patch are arranged on the bottom substrate. In order to further improve the isolation, two fence posts are arranged between adjacent antenna elements on the bottom substrate. A flat patch array printed on an intermediate substrate is used to reduce the mutual coupling factor, broaden the frequency bandwidth, and improve the peak gain and radiation efficiency.

[0008] Reference 5: Dou Haipeng, Chen Xue, and Zhang Wenmei, "Research and Comparison of Two Miniaturized Comb-Shaped Microstrip Antennas," Journal of Changchun University of Technology (Natural Science Edition), 2010, 31(4): 463-466. Two miniaturized microstrip antennas suitable for wireless communication systems are proposed. Both antenna patches adopt a comb-shaped structure design. The combination of patch meandering and loaded short-circuit probes significantly reduces the antenna size. The study shows that both antennas can achieve an operating bandwidth greater than 5 MHz near the 2.4 GHz frequency band.

[0009] As can be seen from the above-mentioned prior art, existing microstrip antennas are complex in design, introduce back cavities, have high profiles, are large in size, and have low gain. Conductor loss, dielectric loss, and surface wave excitation contribute to low efficiency. Poor isolation between the feeder and the radiating element easily induces stray radiation. Surface grooving and loading stubs distort the radiation pattern and increase size, impacting overall integration. Multi-layer designs also increase processing complexity and cost, and in practical applications, they can face challenges in manufacturing difficulty and assembly precision. Summary of the Invention

[0010] In view of the defects and shortcomings of the existing technology, the present invention provides a pavilion-shaped microstrip antenna, which solves the technical bottlenecks of traditional microstrip antennas in miniaturization, gain improvement and radiation stability through innovative structural design.

[0011] Considering the common problems of oversize, insufficient gain, and unstable radiation patterns faced by traditional microstrip antennas in mobile communication applications, a quarter-wavelength structure is still bulky, especially for space-constrained scenarios such as drones and portable devices, and the multi-layer design increases conductor loss and processing difficulty. This invention utilizes a breakthrough single-sided conductive dielectric substrate structure to construct a unique pavilion-shaped radiator, achieving a performance leap through three key innovations: First, a triangular conductive strip is integrated on top of a central rectangular conductive strip, significantly expanding the radiation area and increasing the peak gain to 2.64dBi in actual measurements; second, the symmetrical curved arm is designed as a coil-like structure with multiple continuous bends. By increasing the inductance, the antenna size is effectively reduced to a compact 15.5×20mm²; finally, the conductive strip segment at the end of the curved arm is innovatively maintained at a precise parallel spacing with the ground portion. This design, combined with the coplanar central ground portion and the side ground portions, optimizes current distribution and extends the operating bandwidth to 700MHz (6.2–6.9GHz).

[0012] This structural synergy achieves breakthroughs in multiple dimensions: the coiled bend of the flexure arm not only enables miniaturization but also collaborates with the triangular guide strip to form a stable radiation pattern, producing uniform omnidirectional radiation in the yoz plane (with pattern circularity deviation controlled within ±3dB). Meanwhile, the xoz plane maintains directional radiation characteristics, with a gain fluctuation of only 0.27dBi in the 6-7GHz band. The feed system utilizes a gradual design of a trapezoidal impedance transition zone (the narrow end connects to the vertical feed line, the wide end extends to the rectangular guide strip), achieving near-ideal impedance matching of 51.7+j0.5Ω at the center frequency of 6.5GHz, with a reflection coefficient depth of -35dB.

[0013] The entire structure can be fabricated using single-sided etching, eliminating the need for a conductive layer underneath the dielectric substrate. This avoids the complexity and loss associated with traditional multi-layer designs while significantly reducing production costs. Field measurements have verified that the antenna's reflection coefficient remains consistently below -10dB in the 6.2–6.9GHz frequency band, and its voltage standing wave ratio remains below 2 in the 6.2–6.92GHz band, perfectly meeting the demanding requirements of personal wireless communications and data transmission systems.

[0014] The solutions adopted by the present invention to solve the technical problems specifically include: A pavilion-shaped microstrip antenna includes a dielectric substrate and a radiating patch structure and a ground plane disposed on the same side of the dielectric substrate. The dielectric substrate has a conductive layer only on the side where the radiating patch structure is disposed. The special design of the antenna is as follows: The radiating patch structure includes a central rectangular conductive strip, a triangular conductive strip connected to the top of the central rectangular conductive strip, and curved conductive arms symmetrically distributed on both sides of the central rectangular conductive strip, each curved conductive arm being formed by continuously bending multiple sections of the conductive strip; The ground plate is arranged coplanar with the radiation patch structure, and includes a central ground portion located below the central rectangular conductive strip and side ground portions symmetrically arranged on both sides of the central ground portion; The outermost conductive strip section of the curved conductive arm is parallel to and spaced from the corresponding side grounding portion.

[0015] Furthermore, the curved conductive arm is formed by bending four sections of conductive strips, including a first horizontal section connecting the central rectangular conductive strip, a second vertical section bent vertically, a third horizontal section bent horizontally, and a fourth vertical section extending vertically; the fourth vertical section is arranged parallel to and opposite to the side grounding portion.

[0016] Furthermore, a feeding structure is also included, and the feeding structure includes: A feeder conductor strip vertically connected to the center of the central rectangular conductor strip; A trapezoidal impedance transition zone connected to the end of the feeder conductor strip; A rectangular feed strip connected to a trapezoidal impedance transition strip.

[0017] Furthermore, the narrow end of the trapezoidal impedance transition zone is connected to the feed line conductive strip, and the wide end is connected to the rectangular feed conductive strip.

[0018] Furthermore, the width of the central ground portion is smaller than the width of the side ground portions.

[0019] Furthermore, the conductive strip of the curved conductive arm is bent to form a coil-shaped structure.

[0020] Furthermore, the bottom side of the triangular conductive strip coincides with the wide side of the rectangular conductive microstrip.

[0021] Furthermore, the dielectric material of the dielectric substrate is FR4.

[0022] Furthermore, the dimensions of the curved conductive arm, the triangular conductive strip and the ground plate are configured so that the reflection coefficient of the antenna in the 6.2-6.9 GHz frequency band is less than -10 dB.

[0023] Furthermore, the ratio of the total length of the curved conductive arms to the length of the central rectangular conductive strip is 1.5-2.5.

[0024] Compared with the prior art, the present invention and its preferred embodiments have at least the following beneficial effects: 1. Breakthrough solution to the contradiction between miniaturization and performance The curved conductive arms utilize a coil-like, multi-segment design, significantly increasing antenna inductance and reducing the physical size to less than a quarter wavelength of a traditional microstrip antenna while avoiding the gain loss associated with meander technology. The triangular and rectangular conductive strips work together to expand the radiating area within a compressed space, directly increasing gain and overcoming the industry pain point of rapidly decreasing gain in miniaturized antennas.

[0025] 2. Omnidirectional radiation stability and broadband performance The coplanar ground plane layout optimizes current distribution through central and side ground sections, extending bandwidth to 700MHz. The end-conductor strip segments are spaced parallel to the ground sections to suppress surface wave interference and ensure an undistorted omnidirectional radiation pattern. The trapezoidal impedance transition band ensures smooth matching of the feed system, with the center frequency impedance approaching the ideal 50Ω, addressing the narrow bandwidth and difficult matching issues of traditional antennas.

[0026] 3. Simple manufacturing and low cost advantages The single-sided FR4 dielectric substrate has no conductive bottom layer, eliminating the drilling and alignment processes of traditional multi-layer designs, significantly reducing production costs. The fully etched structure requires no additional welding or assembly, making it suitable for large-scale mass production and promoting the popularization of micro-communication devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 Schematic diagram of the structural parameters of the pavilion-shaped microstrip antenna according to an embodiment of the present invention; Figure 2 is a reflection characteristic curve of the pavilion-shaped microstrip antenna according to an embodiment of the present invention; Figure 3 : is the impedance characteristic curve of the pavilion-shaped microstrip antenna according to an embodiment of the present invention; Figure 4 1 is the E-plane and H-plane directional diagram of the pavilion-shaped microstrip antenna according to an embodiment of the present invention; Figure 5 1 is a voltage standing wave ratio curve of the pavilion-shaped microstrip antenna according to an embodiment of the present invention; Figure 6 is a gain curve of the pavilion-shaped microstrip antenna according to an embodiment of the present invention; Figure 7 2 is a structural characteristic diagram of a pavilion-shaped microstrip antenna according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the features and advantages of the present invention more clearly understood, the following embodiments are given for detailed description: It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] The embodiment of the present invention discloses a pavilion-shaped omnidirectional microstrip antenna operating at 6.5 GHz. The antenna can obtain a relatively good reflection coefficient, an omnidirectional radiation pattern and a relatively high gain, and is mainly used in personal wireless communications and wireless data transmission systems. Figure 7As shown, its main structure includes a triangular conductive microstrip 2, a rectangular conductive microstrip 3, and two symmetrical curved conductive microstrip structures consisting of conductive microstrips 4, 5, 6, and 13, etched on a dielectric substrate material 1 without a ground plane. The feeding structure consists of a conductive strip 7 placed perpendicular to the center of the conductive strip 3, a trapezoidal impedance transition strip 8, and a rectangular conductive strip 9. The ground plane is on the same side of the antenna pattern and consists of a rectangular microstrip 11 and two rectangular microstrips 10 located on both sides thereof. There is no conductive layer on the bottom layer of the dielectric material 1. The excitation is loaded between the rectangular microstrip 11 and the rectangular microstrip 9, as shown in the dotted box 12. In order to reduce the size of the antenna, the pavilion-shaped microstrip antenna structure proposed in this embodiment bends the two symmetrical arms of the antenna into a coil shape, thereby increasing the inductance of the antenna. A triangular microstrip is added above the radiating microstrip to increase the area of ​​the radiating patch and improve the gain. The top conductive layer is 14.

[0031] In the omnidirectional pavilion-shaped microstrip antenna provided by the present invention, a relatively conventional basic design includes a plurality of conductive microstrip patches on one side of a dielectric substrate and a ground plane located below the feeder on the same side.

[0032] The core features of the present invention are as follows: The main radiating patch is formed by etching triangular and rectangular conductive strips on the dielectric plate to increase gain. The symmetrical arms formed by the two conductive microstrips are bent into a coil shape to increase the inductance of the antenna.

[0033] A ground plane is provided on the same surface as the radiation patch to extend the working frequency band of the antenna and for impedance matching.

[0034] The feeding structure consists of a trapezoidal microstrip connected by microstrips of unequal width at both ends, which is used for impedance transition between the feed source and the antenna.

[0035] Based on the above design, any size of this structure is within the scope of protection of the present invention.

[0036] This invention considers the design of a monopole antenna with a wide impedance bandwidth that can fully cover all required frequency bands used by wireless terminals. However, for some mobile or portable devices, a quarter wavelength is still too large. The solution provided is to significantly increase the antenna's output voltage and length by increasing the antenna's contact and inductance. The pavilion-shaped microstrip antenna, on the other hand, bends its two arms into a coil shape, increasing the antenna's inductance while miniaturizing its size.

[0037] The above design of the present invention is suitable for wireless communication devices such as drones, robots, and unmanned vehicles. The pavilion-shaped microstrip antenna disclosed in this invention is easy to integrate, facilitating the miniaturization of communication equipment and meeting the needs of applications such as communication, detection, speed measurement, ranging, and imaging. It is simple to implement, easy to manufacture, and has low process complexity, effectively reducing production costs and possessing a wide range of applications.

[0038] Based on the design scheme provided above, a more specific design example is provided below to more specifically and fully demonstrate the scheme of the embodiment of the present invention. The designed pavilion-shaped microstrip antenna has an operating frequency of 6.5 GHz, a bandwidth of 700 MHz, an antenna peak gain of 2.64 dBi, a port reflection coefficient of less than -10 dB, and a dielectric material of 15.5 mm × 20 mm, FR4, a constant of 4.4, and a thickness of 1.6 mm.

[0039] The geometric configuration of the pavilion-shaped microstrip antenna in this example is as follows: Figure 7 As shown. Figure 7 In the schematic diagram, the feed source 12 passes through a conductive microstrip 9 and then connects to the feed line conductive microstrip 7 through a trapezoidal transition conductive microstrip 8. The radiating microstrip patch consists of a rectangular conductive microstrip 3, a triangular conductive microstrip 2, two symmetrical curved conductive microstrips (composed of conductive microstrips 4, 5, 6, and 13), an insulating dielectric plate 1, and conductive ground planes 10 and 11.

[0040] In this design, a central rectangular conductive strip 3 supports a triangular conductive strip 2 at the top. Extending from either side are curved arms composed of microstrips 4, 5, 6, and 13, their ends maintain a specific distance from the ground plane 10. The ground plane on the same side is composed of the central rectangle 11 and two side rectangles 10, forming a complete pavilion topology. This simple and efficient design provides a solution for mobile communication devices that combines miniaturization, high gain, and omnidirectional radiation capabilities.

[0041] Figure 1A prototype of the designed antenna is presented, along with a visual representation of the design layout. The structural parameter values ​​are: W1=1.6 mm, L1=4.65 mm, W2=14 mm, L2=1.95 mm, L3=2 mm, L4=3.5 mm, W3=0.95 mm, W4=4 mm, W5=0.95 mm, L6=1.1 mm, L7=0.95 mm, W6=2.5 mm, L8=0.5 mm, L9=2 mm, W7=20 mm, W8=3 mm, H=1.6 mm, W9=0.8 mm, L10=0.4 mm, L11=0.35 mm, W10=8.5 mm, L12=0.35 mm, L13=15.5 mm. The above values ​​represent the optimal overall performance. This patent protects this structural shape and is not limited to the specific parameter values ​​listed above.

[0042] Figure 2 The resonant response of the designed pavilion-shaped microstrip antenna is given, and the center frequency f 0 is 6.5 GHz, the corresponding reflection is -35 dB, the impedance bandwidth of -10 dB is 700 MHz, the frequency is from 6.2 GHz to 6.9 GHz, and the relative bandwidth FBW is 10.8%.

[0043] Figure 3 This is the impedance curve. At the center frequency of 6.5 GHz, the impedance is 51.7+j0.5Ω; at 6.2 GHz, the impedance is 36.65-j25.35Ω; at 6.9 GHz, the impedance is 86.5+j24.5Ω.

[0044] Figure 4 The radiation pattern of the antenna in this embodiment at 6.5 GHz is shown in FIG.

[0045] Figure 5 This is the antenna voltage standing wave ratio curve. The frequency band where VSWR is less than 2 is from 6.2 GHz to 6.92 GHz, and the standing wave ratio performance is good.

[0046] Figure 6 This is the gain curve of the antenna in this example. The peak gain of the antenna fluctuates within the range of 2.37-2.64 dBi in the 6 GHz to 7 GHz frequency band, and the gain does not fluctuate much within a wider frequency band.

[0047] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other manner. Any person skilled in the art may utilize the above-disclosed technical content to modify or modify the present invention into equivalent embodiments. However, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical content of the present invention and are based on the technical essence of the present invention remain within the scope of protection of the present invention.

[0049] The present invention is not limited to the above-mentioned best embodiment. Anyone can derive other forms of a pavilion-shaped microstrip antenna based on the inspiration of the present invention. All equivalent changes and modifications made within the scope of application of the present invention should fall within the scope of the present invention.

Claims

1. A pavilion-shaped microstrip antenna comprising a dielectric substrate and a radiating patch structure and a ground plane disposed on the same side of the dielectric substrate, wherein the dielectric substrate has a conductive layer only on the side where the radiating patch structure is disposed, characterized in that: The radiating patch structure includes a central rectangular conductive strip, a triangular conductive strip connected to the top of the central rectangular conductive strip, and curved conductive arms symmetrically distributed on both sides of the central rectangular conductive strip, each curved conductive arm being formed by continuously bending multiple sections of the conductive strip; The ground plate is arranged coplanar with the radiation patch structure, and includes a central ground portion located below the central rectangular conductive strip and side ground portions symmetrically arranged on both sides of the central ground portion; The outermost conductive strip section of the curved conductive arm is parallel to and spaced from the corresponding side grounding portion.

2. The pavilion-shaped microstrip antenna according to claim 1, characterized in that: The curved conductive arm is formed by bending four sections of conductive strips, including a first horizontal section connecting the central rectangular conductive strip, a second vertical section bent vertically, a third horizontal section bent horizontally, and a fourth vertical section extending vertically; the fourth vertical section is arranged parallel to and opposite to the side grounding portion.

3. The pavilion-shaped microstrip antenna according to claim 1, wherein: Also included is a feeding structure, the feeding structure comprising: A feeder conductor strip vertically connected to the center of the central rectangular conductor strip; A trapezoidal impedance transition zone connected to the end of the feeder conductor strip; A rectangular feed strip connected to a trapezoidal impedance transition strip.

4. The pavilion-shaped microstrip antenna according to claim 3, characterized in that: The narrow end of the trapezoidal impedance transition zone is connected to the feeder conductive strip, and the wide end is connected to the rectangular feed conductive strip.

5. The pavilion-shaped microstrip antenna according to claim 1, wherein: The width of the central ground portion is smaller than the width of the side ground portions.

6. The pavilion-shaped microstrip antenna according to claim 1, characterized in that: The conductive strip of the curved conductive arm is bent to form a coil-shaped structure.

7. The pavilion-shaped microstrip antenna according to claim 1, characterized in that: The bottom side of the triangular conductive strip coincides with the wide side of the rectangular conductive microstrip.

8. The pavilion-shaped microstrip antenna according to claim 1, characterized in that: The dielectric material of the dielectric substrate is FR4.

9. The pavilion-shaped microstrip antenna according to claim 1, characterized in that: The dimensions of the curved conductive arm, the triangular conductive strip and the ground plate are configured so that the reflection coefficient of the antenna in the 6.2-6.9 GHz frequency band is less than -10 dB.

10. The pavilion-shaped microstrip antenna according to claim 1, characterized in that: The ratio of the total length of the curved conductive arms to the length of the central rectangular conductive strip is 1.5-2.5.

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