A multi-frequency, multi-tooth, multi-coupled microstrip antenna

Abstract

The present invention discloses a multi-frequency, multi-tooth, multi-coupled microstrip antenna, which includes a single-layer dielectric substrate, a special-shaped multi-tooth, multi-coupled radiating unit on the top surface of the dielectric substrate, a U-shaped radiating unit on the bottom surface of the dielectric substrate, and a feed microstrip line. The special-shaped multi-tooth, multi-coupled radiating unit includes a square radiating unit and a circular radiating unit from the outside to the inside, both of which are connected to the feed microstrip line at the bottom. The square radiating unit is composed of two bilaterally symmetrical multi-tooth conductor wide strips, two bilaterally symmetrical multi-tooth conductor narrow strips, and a narrow strip perpendicular to the feed microstrip line, with the five conductor strips connected end to end. The circular radiating unit is obtained by cutting out a circle from a dodecagon and has multiple teeth on its left and right sides. The U-shaped radiating unit includes two bilaterally symmetrical narrow rectangular conductor strips and a wide rectangular conductor strip at the bottom. The present invention has a simple structure and a small size, is easy to integrate with planar circuits, and can meet the technical requirements of multi-band communication in wireless communications.

Description

Technical Field

[0001] The present invention belongs to the field of antennas, and in particular relates to a multi-frequency, multi-tooth, multi-coupling microstrip antenna. Background Art

[0002] Since the theory of microstrip antennas was first proposed in the mid-20th century, related technologies have advanced significantly. Microstrip antennas, with their advantages of low cost, ease of mass production, compact size, and light weight, have found widespread application in mobile communications, radar, satellite communications, and other fields. To meet the application needs of multi-band wireless communication systems, multi-band microstrip antennas have been a key area of ​​research for researchers both domestically and internationally. Various methods exist to enable multi-band microstrip antennas, including multi-patch technology, bending technology, slotting technology, and parasitic element loading. However, traditional multi-band microstrip antenna technologies suffer from large size, hindering their miniaturization and failing to meet the application requirements of certain multi-band communications applications. Further research is needed to achieve both multi-band and miniaturization of microstrip antennas. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the object of the present invention is to provide a multi-frequency, multi-tooth, multi-coupled microstrip antenna to solve the problem of large size of the multi-frequency microstrip antenna in the prior art.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A multi-frequency, multi-tooth, multi-coupling microstrip antenna comprises a single-layer dielectric substrate for the antenna, a special-shaped multi-tooth, multi-coupling radiating unit arranged on the top surface of the single-layer dielectric substrate for the antenna, a U-shaped radiating unit on the bottom surface, and a feeding microstrip line; the special-shaped multi-tooth, multi-coupling radiating unit is located above the inner side of the U-shaped portion of the U-shaped radiating unit, the feeding microstrip line is arranged above the bottom of the U-shaped radiating unit, and the feeding microstrip line is connected to the special-shaped multi-tooth, multi-coupling radiating unit; the special-shaped multi-tooth, multi-coupling radiating unit comprises a square radiating unit and a circular radiating unit, the circular radiating unit is arranged on the inner side of the square radiating unit, the inner sides of the two side edges of the square radiating unit, the two sides of the circular radiating unit, and the top of the square radiating unit are respectively provided with multi-tooth structures, the tops of the square radiating unit and the circular radiating unit are provided with openings, and the bottoms of the square radiating unit and the circular radiating unit are connected to the feeding microstrip line.

[0006] Furthermore: the square radiation unit includes a first multi-tooth conductor wide strip, a second multi-tooth conductor wide strip, a first multi-tooth conductor narrow strip, a second multi-tooth conductor narrow strip and a bottom narrow strip, the middle of the bottom narrow strip is connected to the feed microstrip line, one end of the bottom narrow strip is connected to the first multi-tooth conductor narrow strip, and the other end is connected to the second multi-tooth conductor narrow strip, the first multi-tooth conductor narrow strip and the second multi-tooth conductor narrow strip are perpendicular to the bottom narrow strip, the first multi-tooth conductor narrow strip is connected to the first multi-tooth conductor wide strip, the first multi-tooth conductor narrow strip is perpendicular to the first multi-tooth conductor wide strip, the second multi-tooth conductor narrow strip is connected to the second multi-tooth conductor wide strip, the second multi-tooth conductor narrow strip is perpendicular to the second multi-tooth conductor wide strip, and the first multi-tooth conductor wide strip and the second multi-tooth conductor wide strip are spaced a distance apart.

[0007] Furthermore, a multi-tooth structure is provided on the inner side of each of the first multi-tooth conductor strip and the second multi-tooth conductor strip, and each multi-tooth structure has seventeen teeth.

[0008] Furthermore, a multi-tooth structure is provided on the top of each of the first multi-tooth conductor wide strip and the second multi-tooth conductor wide strip, and each multi-tooth structure has eight teeth.

[0009] Furthermore: the multi-tooth structures on both sides of the circular frame radiation unit are respectively opposite to the multi-tooth structures of the first multi-tooth conductor narrow strip and the second multi-tooth conductor narrow strip, the multiple tooth amplitude envelopes are triangular, the multiple teeth have different lengths, the middle tooth has the longest length, and the tooth lengths of the middle teeth gradually shorten towards the two sides.

[0010] Furthermore, the top of the circular frame radiation unit presents two left-right symmetrical sharp corners, and the two sharp corners are close to the square frame radiation unit but not connected.

[0011] Furthermore: the inner side of the circular frame radiation unit is circular, and the bottoms of the opposite sides of the first multi-tooth conductor width strip and the second multi-tooth conductor width strip are provided with missing corners, and the missing corners maintain the same arc as the circular shape of the inner side of the circular frame radiation unit.

[0012] Furthermore: the feeding microstrip line includes a trapezoidal microstrip line and a rectangular microstrip line connected to the trapezoidal microstrip line.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) Compared with other traditional microstrip antennas operating in the lowest 900 MHz frequency band, the present invention is smaller in size;

[0015] (2) The present invention adopts multi-tooth multi-coupling antenna technology to achieve multi-band antenna operation, extend the current path, and reduce the volume, which can meet the technical requirements of multi-band wireless communication;

[0016] (3) The antenna is small in size and simple in structure, making it easy to integrate with planar circuits and capable of achieving quasi-omnidirectional radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of the multi-frequency, multi-tooth, multi-coupled microstrip antenna of the present invention;

[0018] Figure 2 is the simulation result of the antenna reflection coefficient S11 parameter;

[0019] Figure 3 is the 926MHz normalized radiation pattern of the multi-frequency, multi-tooth, multi-coupled microstrip antenna;

[0020] Figure 4 is the 1346MHz normalized radiation pattern of the multi-frequency, multi-tooth, multi-coupled microstrip antenna;

[0021] Figure 5 This is the normalized radiation pattern of the multi-frequency, multi-tooth, multi-coupled microstrip antenna at 2319MHz.

[0022] Figure numerals: 1-special-shaped multi-tooth multi-coupling radiation unit, 2-U-shaped radiation unit, 3-feed microstrip line, 11-square radiation unit, 12-circular radiation unit, 111-first multi-tooth conductor wide strip, 112-second multi-tooth conductor wide strip, 113-first multi-tooth conductor narrow strip, 114-second multi-tooth conductor narrow strip, 115-bottom narrow strip, 31-trapezoidal microstrip line, 32-rectangular microstrip line. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] The application principle of the present invention is described in detail below with reference to the accompanying drawings.

[0025] like Figure 1The microstrip multi-frequency antenna shown in the figure includes an antenna single-layer dielectric substrate, a special-shaped multi-tooth multi-coupled radiating unit 1 coated on the top surface of the dielectric substrate, a U-shaped radiating unit 2 coated on the bottom surface of the dielectric substrate, and a feeding microstrip line 3; the center axes of the special-shaped multi-tooth multi-coupled radiating unit 1, the U-shaped radiating unit 2, and the feeding microstrip line 3 are on the same straight line, forming a bilaterally symmetrical structure; the special-shaped multi-tooth multi-coupled radiating unit 1 includes a square frame radiating unit 11 and a circular frame radiating unit 12 from the outside to the inside, and the bottom is connected to the square frame radiating unit 11 and the circular frame radiating unit 12. The feeding microstrip line 3 is connected; the square radiation unit 11 is composed of two sections of multi-tooth conductor wide strips symmetrically on the left and right, two sections of multi-tooth conductor narrow strips symmetrically on the left and right, and a narrow strip perpendicular to the feeding microstrip line. The five sections of conductor strips are connected end to end, including a first multi-tooth conductor wide strip 111, a second multi-tooth conductor wide strip 112, a first multi-tooth conductor narrow strip 113, a second multi-tooth conductor narrow strip 114 and a bottom narrow strip 115. The middle of the bottom narrow strip 115 is connected to the feeding microstrip line 3. One end of the bottom narrow strip 115 is connected to the first multi-tooth conductor narrow strip 113, and the other end is connected to the second multi-tooth conductor narrow strip 114. The first multi-tooth conductor narrow strip 113 and the second multi-tooth conductor narrow strip 114 are perpendicular to the bottom narrow strip 115. The first multi-tooth conductor narrow strip 113 is connected to the first multi-tooth conductor wide strip 111, and the first multi-tooth conductor narrow strip 113 is perpendicular to the first multi-tooth conductor wide strip 111. The second multi-tooth conductor narrow strip 114 is connected to the second multi-tooth conductor wide strip 112, and the second multi-tooth conductor narrow strip 114 is perpendicular to the second multi-tooth conductor wide strip 112. There is a distance between the first multi-tooth conductor wide strip 111 and the second multi-tooth conductor wide strip 112; the circular frame radiation unit 12 is obtained by digging out a circle from a dodecagon with a side length of L3, and has multiple teeth on the left and right sides; the U-shaped radiation unit 2 includes two sections of conductor narrow rectangular strips that are symmetrical on the left and right and a conductor wide rectangular strip at the bottom, and the overall structure is U-shaped.

[0026] Specifically, the long sides of the first and second multi-tooth conductor strips 111, 112 are horizontal, with a length of L5 and a width of W3. Each strip has eight teeth on its top, and a corner is missing at its lower right corner. The spacing between the first and second multi-tooth conductor strips 111, 112 is D1.

[0027] The long sides of the first multi-tooth conductor strip 113 and the second multi-tooth conductor strip 114 are in the vertical direction. The long side of the multi-tooth conductor strip is L4 in length and W4 in width, and seventeen teeth are formed on the inner side.

[0028] The nine teeth on the left and right sides of the circular frame radiation unit 12 are opposite to the multiple teeth of the two sections of multi-tooth conductor narrow strips. The amplitude envelope of the nine teeth is triangular. The nine teeth are of different lengths, and the middle tooth is the longest.

[0029] The circular frame radiation unit 12 has a wide bottom and a narrow top, and the top presents two symmetrical sharp corners, which are close to the top of the square frame radiation unit but are not connected.

[0030] The feeding microstrip line 3 includes a trapezoidal microstrip line 31 and a rectangular microstrip line 32 connected to the trapezoidal microstrip line 31. The height of the trapezoidal microstrip line is L1 and the upper base width is W1. The lower base width of the trapezoidal microstrip line is the same as the width of the rectangular microstrip line, both of which are W2. The total length of the feeding microstrip line is L2.

[0031] The multiple couplings of the special-shaped multi-tooth multi-coupling radiating unit 1 and the U-shaped radiating unit 2 are the main reason for the antenna to generate multi-band radiation, and the multiple teeth play a role in reducing the antenna frequency. Whether the square radiating unit 11 in the special-shaped multi-tooth multi-coupling radiating unit 1 is connected to the feeding microstrip line, and whether the two sharp corners of the circular radiating unit 12 are close to the top of the square radiating unit and are not connected, will affect whether the lowest operating frequency band resonates. The special-shaped multi-tooth multi-coupling radiating unit 1 and the U-shaped radiating unit 2 not only participate in the antenna radiation, but also play a role in impedance matching. Adjusting the size parameters of these two units is conducive to adjusting the matching of each frequency band.

[0032] In the embodiment of the present invention, when the antenna substrate is a WL-CT350 substrate (ε r =3.48, tanδ = 0.004), after optimizing the antenna structure and dimensions using the simulation software HFSS, the overall length L of the antenna dielectric substrate is 58mm and the width W is 55mm. The antenna dimensions use the following parameters:

[0033] W1=6.2mm, W2=12.8mm, W3=8.1mm, W4=2.9mm, D1=12mm, L1=5.4mm,

[0034] L2 = 9.7mm, L3 = 11.1mm, L4 = 50.7mm, L5 = 19mm, L6 = 6.3mm, L7 = 12.8mm, L8 = 13.9mm, S = 1.1mm. Furthermore, the radius of the circle cut out of the dodecagon is 18.3mm. The length and width of the eight teeth above the two wide multi-tooth conductor strips are 2.2mm and 1mm respectively, while the length and width of the seventeen teeth inside the two narrow multi-tooth conductor strips are 1.9mm and 1mm respectively. The nine teeth on the left and right sides of the circular radiating element are 1mm wide, and the width of the two symmetrical narrow rectangular conductor strips in the U-shaped radiating element is 1.5mm.

[0035] Figure 2 is the obtained antenna reflection coefficient S11 parameter simulation result. Figure 2As can be seen, when the antenna reflection coefficient S11 is less than -10dB (corresponding to a standing wave ratio (VSWR) ≤ 2), the antenna resonant frequencies are 926 / 1346 / 2319 MHz, respectively. Table 1 lists the antenna's reflection coefficient, antenna efficiency, and gain at each resonant frequency. The gain at each resonant frequency is 2.2dBi (926 MHz), 3.86dBi (1346 MHz), and 5.48dBi (2319 MHz), meeting the requirements of typical applications.

[0036] Table 1 Antenna parameters

[0037]

[0038] Figures 3 to 5 is the normalized radiation pattern at each frequency point, where Figure 3 is the 926MHz normalized radiation pattern of the multi-frequency, multi-tooth, multi-coupled microstrip antenna; Figure 4 is the 1346MHz normalized radiation pattern of the multi-frequency, multi-tooth, multi-coupled microstrip antenna; Figure 5 This is the normalized radiation pattern of the multi-frequency, multi-tooth, multi-coupled microstrip antenna at 2319 MHz. The normalized radiation patterns at each frequency point demonstrate that the antenna's directivity meets the requirements for wireless communications applications.

[0039] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-frequency, multi-tooth, multi-coupled microstrip antenna, characterized by: The invention comprises an antenna single-layer dielectric substrate, a special-shaped multi-tooth multi-coupling radiation unit (1) arranged on the top surface of the antenna single-layer dielectric substrate, a feeding microstrip line (3), and a U-shaped radiation unit (2) on the bottom surface; the special-shaped multi-tooth multi-coupling radiation unit (1) is located above the inner side of the U-shaped portion of the U-shaped radiation unit (2); the feeding microstrip line (3) is arranged above the bottom of the U-shaped radiation unit (2); the feeding microstrip line (3) is connected to the special-shaped multi-tooth multi-coupling radiation unit (1); the special-shaped multi-tooth multi-coupling radiation unit (1) comprises a square frame radiation unit (11) and a round frame radiation unit (12); the round frame radiation unit (12) is arranged on the inner side of the square frame radiation unit (11); The inner side, the inner sides of the two side edges of the square frame radiation unit (11), the two outer sides of the circular frame radiation unit (12) and the outer side of the top of the square frame radiation unit (11) are respectively provided with a multi-tooth structure, the tops of the square frame radiation unit (11) and the circular frame radiation unit (12) are provided with an opening, and the bottoms of the square frame radiation unit (11) and the circular frame radiation unit (12) are connected to the feeding microstrip line (3); the square frame radiation unit (11) is composed of two sections of multi-tooth conductor wide strips that are symmetrical on the left and right, two sections of multi-tooth conductor narrow strips that are symmetrical on the left and right, and a narrow strip that intersects the feeding microstrip line at right angles; the circular frame radiation unit (12) is obtained by digging out a circle from a dodecagon with a side length of L3, and has multiple teeth on the left and right outer sides.

2. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 1, characterized in that: The square frame radiation unit (11) comprises a first multi-tooth conductor wide strip (111), a second multi-tooth conductor wide strip (112), a first multi-tooth conductor narrow strip (113), a second multi-tooth conductor narrow strip (114) and a bottom narrow strip (115); the middle of the bottom narrow strip (115) is connected to the feed microstrip line (3); one end of the bottom narrow strip (115) is connected to the first multi-tooth conductor narrow strip (113), and the other end is connected to the second multi-tooth conductor narrow strip (114); the first multi-tooth conductor narrow strip (113) and the second multi-tooth conductor narrow strip (114) The first multi-tooth conductor narrow strip (113) is perpendicular to the bottom narrow strip (115), connected to the first multi-tooth conductor wide strip (111), the first multi-tooth conductor narrow strip (113) is perpendicular to the first multi-tooth conductor wide strip (111), the second multi-tooth conductor narrow strip (114) is connected to the second multi-tooth conductor wide strip (112), the second multi-tooth conductor narrow strip (114) is perpendicular to the second multi-tooth conductor wide strip (112), and the first multi-tooth conductor wide strip (111) and the second multi-tooth conductor wide strip (112) are spaced a distance apart.

3. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 2, characterized in that: A multi-tooth structure is provided on the inner side of each of the first multi-tooth conductor strip (113) and the second multi-tooth conductor strip (114), and each multi-tooth structure has seventeen teeth.

4. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 2, characterized in that: The top outer sides of the first multi-tooth conductor width strip (111) and the second multi-tooth conductor width strip (112) are respectively provided with a multi-tooth structure, and the number of teeth of each multi-tooth structure is eight; the length and width of the eight teeth above the two sections of the multi-tooth conductor width strip are 2.2 mm and 1 mm respectively.

5. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 3, characterized in that: The multi-tooth structures on the two outer sides of the circular frame radiation unit (12) are respectively opposite to the multi-tooth structures of the first multi-tooth conductor narrow strip (113) and the second multi-tooth conductor narrow strip (114), and the multiple teeth amplitude envelope is presented as a triangle. The multiple teeth have different lengths, the length of the middle tooth is the longest, and the length of the teeth on the middle teeth toward the two sides gradually shortens; the left and right outer sides of the circular frame radiation unit (12) are specifically nine teeth, and the nine teeth are opposite to the multi-tooth structures of the first multi-tooth conductor narrow strip (113) and the second multi-tooth conductor narrow strip (114).

6. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 1, characterized in that: The top of the circular frame radiation unit (12) presents two left-right symmetrical sharp corners, and the two sharp corners are close to the square frame radiation unit (11), but are not connected.

7. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 2, characterized in that: The inner side of the circular frame radiation unit (12) is circular, and the bottoms of the opposite sides of the first multi-tooth conductor width strip (111) and the second multi-tooth conductor width strip (112) are provided with missing corners, and the missing corners maintain the same arc as the circular shape of the inner side of the circular frame radiation unit (12).

8. The multi-frequency, multi-tooth, multi-coupled microstrip antenna according to claim 1, characterized in that: The feeding microstrip line (3) comprises a trapezoidal microstrip line (31) and a rectangular microstrip line (32) connected to the trapezoidal microstrip line.

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