Low-cost ultrathin broadband microstrip antenna array

Abstract

The invention discloses a low-cost ultrathin broadband microstrip antenna array which is characterized by comprising a metal ground layer, a dielectric layer and a metal patch layer which are sequentially arranged from bottom to top, the metal patch layer comprises a radiation layer and a power dividing feed network, the radiation layer comprises metal patch array elements which are arranged in a periodic array mode, and the power dividing feed network is connected with the metal patch array elements. The metal patch array elements are connected through the power division feed network; the metal patch array element is a rectangular metal patch of which the two corners of the long side are cut, the rectangular metal patch is also provided with three open slots which are arranged in a triangular manner, and the open slots are parallel to the corresponding sides of the rectangular metal patch. According to the invention, the low profile is ensured, the relative bandwidth of 4.5% is realized, the patch is miniaturized by chamfering and slotting the patch, and the patch has the advantages of low cost and stable structure, and is suitable for batch production and processing.

Description

Technical Field

[0001] This invention belongs to the field of microstrip antenna technology, specifically relating to a low-cost, ultra-thin broadband microstrip antenna array. Background Technology

[0002] Microstrip antennas have been widely used in radar, satellite communications, and mobile terminals since the 1970s due to their outstanding advantages such as low profile, light weight, ease of fabrication, and compatibility with circuit boards. Their basic structure consists of three layers: a radiating patch, a dielectric substrate, and a metal ground plane; essentially, they are resonant devices.

[0003] However, traditional microstrip antennas suffer from two inherent, interconnected drawbacks that severely limit their application in the latest generation of wireless systems: firstly, their extremely narrow impedance bandwidth; and secondly, their strong dependence on the thickness of the dielectric substrate. The impedance bandwidth of an antenna (typically measured by a voltage standing wave ratio (VSWR) < 2) is directly proportional to the thickness of its dielectric substrate. Both theoretical analysis and practical application demonstrate that the bandwidth of a typical rectangular microstrip antenna is usually only 1% to 3% of its center frequency.

[0004] To broaden bandwidth, those skilled in the art typically employ a series of classic solutions, mainly including: 1. Increasing the thickness of the dielectric substrate: The bandwidth is approximately proportional to the substrate thickness. However, this will significantly increase the size, weight, and profile height of the antenna, deviating from the core advantage of the low profile of microstrip antennas, and will excite stronger surface waves, reducing radiation efficiency.

[0005] 2. Use a low dielectric constant substrate: Reducing the dielectric constant of the substrate can reduce the confinement of the field, which is beneficial for widening the bandwidth. However, low dielectric constant materials (such as air, foam, etc.) often have poor mechanical strength and are not conducive to reducing the electrical size of the radiating patch.

[0006] 3. Introducing multi-resonant structures: For example, using U-shaped slots, E-shaped patches, or double-layer stacked patch structures to expand the overall bandwidth by introducing multiple adjacent resonant points. However, these methods inevitably increase the structural complexity of the antenna, the profile height (stacked scheme), and the manufacturing cost.

[0007] With the rapid development of 5G and future mobile communication technologies, wearable devices, and IoT terminals have placed almost stringent demands on antennas: extreme thinness (commonly found in device casings), wide bandwidth (covering multiple frequency bands), high performance, and ease of mass production. Traditional broadband solutions and the demand for ultra-thin antennas have created a fundamental contradiction. On the one hand, pursuing ultra-thinness (e.g., substrate thickness less than 1mm) drastically degrades the inherently narrow bandwidth and causes a sharp drop in radiation efficiency due to increased ohmic and dielectric losses, rendering the antenna impractical. On the other hand, complex multi-layered stacked structures struggle to meet the extreme requirements of terminal devices in terms of internal space and assembly processes.

[0008] How to achieve both wide bandwidth and stable radiation characteristics under the strict constraints of ultra-thin design has become a technical challenge in this field and an urgent need for antenna research and industry. Summary of the Invention

[0009] Purpose of the invention / Technical problem This invention addresses the deficiencies and technical problems existing in the prior art by proposing a low-cost ultrathin broadband microstrip antenna array, which solves the problem of narrow bandwidth in the ultrathin design of traditional microstrip antennas.

[0010] Technical Solution: To achieve the above-mentioned technical objectives, the present invention is implemented through the following technical solution: a low-cost ultrathin broadband microstrip antenna array, comprising a metal ground layer, a dielectric layer and a metal patch layer arranged sequentially from bottom to top, wherein the metal patch layer includes a radiating layer and a power divider feed network, wherein the radiating layer includes metal patch array elements arranged in a periodic array, and the metal patch array elements are connected through the power divider feed network; The metal patch array element is a rectangular metal patch with its long side and two corners cut off. The rectangular metal patch also has three slots arranged in a triangular pattern, and the slots are arranged parallel to the corresponding sides of the rectangular metal patch.

[0011] Preferably, the metal patch array element has an external dimension of 13.4 mm × 24 mm and an element spacing of 35 mm.

[0012] Preferably, the two cut corners are isosceles right angles with a side length of 3.8mm, the size of the slot parallel to the long side of the rectangular metal patch is 7.8mm×1mm, and the size of the two slots parallel to the short side of the rectangular metal patch is 6.56mm×1mm.

[0013] Preferably, the dielectric layer uses an SD106K dielectric substrate with a node constant of 4.05 and a loss tangent of 0.006.

[0014] Preferably, the power distribution network adopts a 1-to-6 equal amplitude in-phase power distribution network.

[0015] Preferably, the power distribution network adopts a side-feeding method.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following advantages: (1) The present invention belongs to the field of antennas, and ensures low profile ( At the same time, it achieved a relatively wide bandwidth, with a relative bandwidth of 4.5%. (2) This invention achieves miniaturization of the patch by chamfering and slotting. (3) This invention has the advantages of low cost and stable structure, and is suitable for mass production. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the low-cost ultrathin broadband microstrip antenna array described in this invention.

[0018] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0019] Figure 3 The image shows the VSWR parameter curves of the antenna array in an embodiment of the present invention.

[0020] Figure 4 This is the e-plane radiation pattern of the antenna array in an embodiment of the present invention.

[0021] Figure 5 This is the h-plane radiation pattern of the antenna array in an embodiment of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specifically stated, the relative arrangement, expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0023] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used here to describe the spatial positional relationship of a device or feature as shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figure. For example, if the device in the figure is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations).

[0024] like Figure 1 and 2 As shown, the low-cost ultrathin broadband microstrip antenna array of the present invention includes a metal ground layer, a dielectric layer, and a metal patch layer arranged sequentially from bottom to top. The metal patch layer includes a radiating layer and a power divider feed network, which are located on the same layer, making the overall structure easy to manufacture and inexpensive. The radiating layer includes metal patch array elements arranged in a periodic array, and the metal patch array elements are connected through the power divider feed network. The metal patch array element is a rectangular metal patch with two isosceles triangles cut off from its long side. The rectangular metal patch also has three slots arranged in a triangular pattern, with the slots parallel to the corresponding sides of the rectangular metal patch. The metal patch array has external dimensions of 13.4 mm × 24 mm and a spacing of 35 mm. As a preferred embodiment, the two corners of the cut metal patch array are isosceles right angles with a side length of 3.8 mm. The size of the slot parallel to the long side of the rectangular metal patch is 7.8 mm × 1 mm, and the size of the two slots parallel to the short side of the rectangular metal patch is 6.56 mm × 1 mm.

[0025] The dielectric substrate uses low-cost SD106K with a dielectric constant of 4.05 and a loss tangent of 0.006, and a thickness of 0.81 mm. Compared to Rogers substrates, its overall cost is significantly reduced. The power divider network and the radiating patch are located on the same layer, making the overall structure easy to manufacture.

[0026] As a preferred embodiment, the power distribution network of this invention employs a 1-to-16 equal-radiation in-phase feed, which expands the bandwidth and ensures the phase consistency of multiple radiating patches, thereby improving the array gain. The feeding method uses side feeding, and open-circuit stubs at the ports are used for tuning to compensate for manufacturing errors.

[0027] Figure 3The figure shows the VSWR parameter curve of the antenna array in this embodiment. In the frequency band of 5.692GHz to 5.95GHz, VSWR < 2, and the relative bandwidth reaches 4.5%.

[0028] Figure 4 The antenna array in this embodiment has an e-plane radiation pattern with a maximum gain of 16.6 dB and a half-power beamwidth of 18.62°.

[0029] Figure 5 The image shows the h-plane radiation pattern of the antenna array in this embodiment, with a maximum gain of 16.6 dB and a half-power beamwidth of 18.72°. It should be noted that the structure described in this invention can be implemented in many different forms and is not limited to the embodiments described. Any equivalent transformations made by those skilled in the art based on the description and drawings of this invention, or direct or indirect applications in other related technical fields, such as the loading and unloading of other items, are included within the protection scope of this invention.

Claims

1. A low-cost, ultrathin broadband microstrip antenna array, characterized in that: It includes a metal ground layer, a dielectric layer and a metal patch layer arranged sequentially from bottom to top. The metal patch layer includes a radiating layer and a power divider network. The radiating layer includes metal patch array elements arranged in a periodic array. The metal patch array elements are connected through the power divider network. The metal patch array element is a rectangular metal patch with its long side and two corners cut off. The rectangular metal patch also has three slots arranged in a triangular pattern, and the slots are arranged parallel to the corresponding sides of the rectangular metal patch.

2. The low-cost ultrathin broadband microstrip antenna array according to claim 1, characterized in that: The metal patch array element has an external dimension of 13.4 mm × 24 mm and an element spacing of 35 mm.

3. The low-cost ultrathin broadband microstrip antenna array according to claim 2, characterized in that: The two cut corners are isosceles right angles with a side length of 3.8mm. The size of the slot parallel to the long side of the rectangular metal patch is 7.8mm×1mm, and the size of the two slots parallel to the short side of the rectangular metal patch is 6.56mm×1mm.

4. The low-cost ultrathin broadband microstrip antenna array according to claim 1, characterized in that: The dielectric layer uses an SD106K dielectric substrate with a node constant of 4.05 and a loss tangent of 0.

006.

5. The low-cost ultrathin broadband microstrip antenna array according to claim 1, characterized in that: The power distribution network adopts a 1-to-6 equal amplitude in-phase power distribution network.

6. The low-cost ultrathin broadband microstrip antenna array according to claim 5, characterized in that: The power distribution network adopts a side-feeding method.

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