A one-transmitting and one-receiving omnidirectional antenna based on a 3D printing process

Abstract

The application discloses an antenna technical field and relates to a one-transmitting-one-receiving omnidirectional antenna based on a 3D printing process, which comprises a PCB board and transmitting antennas and receiving antennas arranged on the two sides of the PCB board respectively, and the transmitting antennas and the receiving antennas are of the same structure; the transmitting antenna comprises a circular waveguide structure, a plurality of windows arranged on the side wall of the circular waveguide structure, and a coaxial inner conductor, a waveguide transition structure, a semicircular waveguide structure and an L-shaped bending conversion structure arranged in the circular waveguide structure in sequence, and a baffle for extending to the coaxial inner conductor is arranged on the window; the application combines the 3D printing process requirements, designs a one-transmitting-one-receiving horizontal omnidirectional waveguide antenna, designs a waveguide antenna and a chip feeding structure, can meet the miniaturization and integration requirements, is installed on a wireless sensor, and metal 3D printing does not need a mold; from a three-dimensional model to a finished part, only printing parameter setting, forming and simple post-processing are needed, and the research and development cycle is shortened.

Description

Technical Field

[0001] This invention relates to the field of antennas, and more specifically to a single-transmitter, single-receiver omnidirectional antenna based on 3D printing technology. Background Technology

[0002] Omnidirectional antennas have wide application value because they can provide all-round coverage without relying on beam scanning or turntables to achieve large-angle electromagnetic signal coverage. An omnidirectional antenna is an antenna that can radiate uniformly within a 360° range and is often used in the Internet of Things, short-range target detection and sensing, and other fields. Traditional omnidirectional antenna designs usually use simple structures, such as dipole antennas and vertical antennas, but such antennas usually have certain limitations in terms of gain, bandwidth and efficiency.

[0003] Waveguide antennas mostly use metal structures, which have the advantages of low transmission loss and high antenna radiation efficiency, making them particularly suitable for the millimeter-wave band. Traditional metal parts manufacturing requires multiple steps, including "mold design, mold processing, part forming, and post-processing". Mold development cycles often take weeks or even months, and mold costs are high. Omnidirectional antennas can be achieved by setting several radiation slots on a circular waveguide, but these complex antenna structures are often difficult to manufacture. Summary of the Invention

[0004] The purpose of this invention is to provide a single-transmitter, single-receiver omnidirectional antenna based on 3D printing technology, which solves the problems existing in the production and processing of existing antennas.

[0005] The present invention achieves the above objectives through the following technical solution: a 3D printing-based omnidirectional antenna with one transmitter and one receiver, comprising: a PCB board and a transmitting antenna and a receiving antenna respectively disposed on both sides of the PCB board, wherein the transmitting antenna and the receiving antenna have the same structure;

[0006] The transmitting antenna includes a quasi-circular waveguide structure, several windows on the sidewall of the quasi-circular waveguide structure, and a coaxial inner conductor, a waveguide transition structure, a semi-circular waveguide structure, and an L-shaped bending transition structure arranged sequentially within the quasi-circular waveguide structure. The windows are provided with baffles for extending into the coaxial inner conductor.

[0007] Preferably, the quasi-circular waveguide structure is a cylinder with a central indentation, and several windows are arranged in a ring in the recessed area of ​​the cylinder.

[0008] Preferably, the window is trumpet-shaped, the baffle is a cuboid, the baffle is located on the inside of the window and has a gap between it and the inner conductor of the coaxial line.

[0009] Preferably, the top of the inner cavity of the quasi-circular waveguide structure is provided with a cylindrical block, and the inner conductor of the coaxial line is disposed on the cylindrical block.

[0010] Preferably, the waveguide transition structure is inclined toward the axis of the quasi-circular waveguide structure, and the inclination angle is acute.

[0011] Preferably, the PCB board includes a dielectric layer and a first metal layer and a second metal layer disposed on both sides of the dielectric layer. Both the first metal layer and the second metal layer are provided with windows. The window of the first metal layer is aligned with the end of the L-shaped bending conversion structure of the transmitting antenna, and the window of the second metal layer is aligned with the end of the L-shaped bending conversion structure of the receiving antenna. The dielectric layer is provided with two SIW to GCPW transition structures respectively connected to the two windows. Metallized vias are provided around the SIW to GCPW transition structures.

[0012] Preferably, the contact area between the receiving antenna and the PCB board is provided with a cuboid cavity.

[0013] Preferably, the semi-circular waveguide structure is arranged horizontally.

[0014] Preferably, the end of the inner conductor of the coaxial line extends into the semi-circular waveguide structure.

[0015] Preferably, the transmitting antenna and the receiving antenna are symmetrical about the center of the PCB board rotated 180°.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. The main structure of the antenna is a quasi-circular waveguide with multiple evenly distributed horn-shaped windows on its side. Electromagnetic waves radiate outward from these windows. Because this structure requires the electromagnetic waves within the quasi-circular waveguide to primarily be TM (transient electromagnetic waves). 01 The electromagnetic wave field of this mode points from the center outwards, therefore coaxial feeding is used; the top of the quasi-circular waveguide has an 8-plate baffle structure, TM 01 In the case of a rectangular window, there is no voltage difference on both sides, and the electric field has a very weak ability to radiate outward. The sloping structure can generate a voltage difference on both sides of the horn window, which greatly enhances the radiation ability of the electric field, thereby achieving a horizontal omnidirectional radiation pattern.

[0018] 2. By rationally arranging the size of the cuboid cavity, high isolation between the transmitting and receiving antennas is achieved; the ports of the transmitting and receiving antennas are all located at the end of the GCPW structure, which can be directly replaced with BGA packaged chips for easy connection to the chip; the inner conductor of the coaxial line has a section that tilts towards the center and a section of semi-circular waveguide structure are used to meet the structural requirements of 3D printing, improve the isolation between the transmitting and receiving antennas, and achieve the unsupported design inside the 3D printed structure. At the same time, it realizes a horizontally polarized omnidirectional antenna, and the loaded PCB board structure is conducive to the integration of the antenna and the chip, realizing an integrated design;

[0019] 3. In accordance with the requirements of 3D printing technology, a horizontal omnidirectional waveguide antenna with one transmitter and one receiver was designed. The waveguide antenna and chip feeding structure were designed to meet the requirements of miniaturization and integration. When installed in a wireless sensor, metal 3D printing does not require molds. From the 3D model to the finished part, only the printing parameter setting, molding and simple post-processing need to be completed. The R&D cycle can be shortened by 50%-90% and the production cost can be reduced. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the omnidirectional antenna structure with one transmitter and one receiver according to the present invention;

[0021] Figure 2 This is a schematic diagram of the PCB board structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the second metal layer structure of the present invention;

[0023] Figure 4 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the middle;

[0024] Figure 5 This is a cross-sectional view of the connection between the transmitting antenna and the receiving antenna of the present invention;

[0025] Figure 6 For the present invention Figure 5 Enlarged schematic diagram of the structure at point B;

[0026] Figure 7 This is a schematic cross-sectional view of the transmitting antenna structure of the present invention;

[0027] Figure 8 This is a schematic diagram of the simulation results of the reflection coefficient of the single-transmitter, single-receiver omnidirectional antenna of the present invention;

[0028] Figure 9 This is a schematic diagram of the isolation simulation results of the single-transmitter and single-receiver omnidirectional antenna of the present invention;

[0029] Figure 10 This is a schematic diagram showing the horizontal radiation pattern of the omnidirectional antenna with one transmitter and one receiver at 60GHz according to the present invention.

[0030] In the diagram: 1. Transmitting antenna; 101. Quasi-circular waveguide structure; 102. Window; 103. Baffle; 104. Cylindrical block; 105. Coaxial inner conductor; 106. Waveguide transition structure; 107. Semi-circular waveguide structure; 108. L-shaped bending transition structure; 2. Receiving antenna; 201. Cuboid cavity; 3. PCB board; 301. First metal layer; 302. Window; 303. Metallized via; 304. Second metal layer; 305. SIW to GCPW transition structure; 306. Dielectric layer. Detailed Implementation

[0031] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0032] Example 1

[0033] Please see Figure 1 A 3D-printed omnidirectional antenna with one transmitter and one receiver includes: a PCB board 3 and a transmitting antenna 1 and a receiving antenna 2 respectively disposed on the upper and lower sides of the PCB board 3. The transmitting antenna 1 and the receiving antenna 2 have the same structure.

[0034] Please see Figure 1 , Figure 5 and Figure 7 The transmitting antenna 1 includes a quasi-circular waveguide structure 101. Several windows 102 are formed on the sidewalls of the quasi-circular waveguide structure 101. Each window 102 is horn-shaped, and each side of the window 102 has a cuboid-shaped baffle 103 located inside the quasi-circular waveguide structure 101. This structure requires the electromagnetic waves within the quasi-circular waveguide to primarily be TM. 01 The electromagnetic wave electric field of this mode points from the center outwards, therefore coaxial feeding is used; TM 01 In this mode, there is no voltage difference on both sides of the rectangular window, and the electric field radiation capability is very weak. The baffle structure can generate a voltage difference on both sides of the horn-shaped window, greatly enhancing the electric field radiation capability. The size of the horn-shaped window 102 is 1.11mm*2.38mm, and the size of the baffle 103 is 1.55mm*2.55mm with a thickness of 0.2mm. The top of the inner cavity of the quasi-circular waveguide structure 101 is provided with a metal cylindrical block 104, and the end of the metal cylindrical block 104 is provided with a coaxial inner conductor 105. The radius of the metal cylindrical block 104 is 1.92mm and the height is 2.82mm. The metal cylindrical block 104 can also provide adjustment and matching. There is a transition section (i.e., waveguide transition structure 106) between the quasi-circular waveguide structure 101 and the coaxial inner conductor 105 that is inclined towards the center. The tilt angle of the waveguide transition structure 106 is an acute angle (0-90 degrees). To realize the quasi-circular waveguide™ 01 The coaxial cable is fed in a mode, and the other end is connected to a semi-circular waveguide structure 107 with a radius of 1.71 mm. The semi-circular waveguide structure 107 is horizontally positioned, and the other end of the semi-circular waveguide structure 107 is transformed into a rectangular waveguide structure by an L-shaped bend 108. The rectangular waveguide structure has dimensions of 3.42 mm * 1.2 mm. After being gradually reduced to 3.266 mm * 0.444 mm, the rectangular waveguide structure is connected to the PCB board 3. This is to achieve the desired effect for the circular waveguide™. 01The power supply was originally implemented using a coaxial-to-rectangular waveguide, but to meet the requirements of 3D printing, it was changed to a semi-circular waveguide.

[0035] It should be noted that both the transmitting antenna 1 and the receiving antenna 2 are cylinders with a radius of 7.5 mm and a height of 15.9 mm. The cylinder is concave in the middle (i.e., an annular groove is formed on the side wall of the cylinder). The window 102 is located in the annular groove, which facilitates energy radiation. The baffle structure formed on the upper and lower surfaces of the annular groove is beneficial to the plasticity of the radiation pattern. The above structure is manufactured using metal 3D printing technology. The receiving antenna 2 and the transmitting antenna 1 have the same shape and size. The two are symmetrical about the center position of the PCB board 3 by rotating 180°.

[0036] Please see Figure 2 , Figure 3 , Figure 4 and Figure 6 The PCB board 3 includes a dielectric layer 306 and a first metal layer 301 and a second metal layer 304 respectively disposed on the upper and lower sides of the dielectric layer 306. The first metal layer 301, the second metal layer 304 and the dielectric layer 306 are circular. The PCB board 3 is divided at the center, and a ground-coplanar waveguide (GCPW) to substrate integrated waveguide (SIW) transmission line (i.e., SIW to GCPW transition structure 305) is disposed on the left and right sides respectively. The upper surface copper layer (first metal layer 301) of the right SIW to GCPW transition structure 305 has a rectangular first... A window 302 is used to power the transmitting antenna 1 (the first window 302 is aligned with the end of the rectangular waveguide of the transmitting antenna 1). A first window 302 is opened on the lower surface of the copper layer (second metal layer 304) of the left SIW to GCPW transition structure 305 to power the receiving antenna 2 (the second window 302 is aligned with the end of the rectangular waveguide of the receiving wire). Metallized vias 303 are provided around both sets of SIW to GCPW transition structures 305. The metallized vias 303 extend from the first metal layer 301 to the second metal layer 304.

[0037] It should be noted that the thickness of the first metal layer 301 and the second metal layer 304 is 0.035 mm, and the dielectric layer 306 is made of RO3003 material with a dielectric constant of 3 and a thickness of 0.127 mm; from Figure 8 It can be seen that the reflection coefficients of the transmitting and receiving antennas are all less than -10dB in the 58GHz-62GHz frequency range, and the transmission from the antenna port to the radiation window is normal within the operating bandwidth; from Figure 9 It can be seen that the isolation of the transmit and receive antennas is better than -50dB in the 58GHz-62GHz frequency range, indicating high isolation. Figure 10The results show that the transceiver antenna has a horizontal omnidirectional gain greater than 1.89 dBi at 60 GHz, and the difference between the maximum and minimum gain is less than 3 dBi, indicating high horizontal gain and omnidirectional performance. This data was obtained through HFSS simulation. The antenna operates in the 58 GHz-62 GHz frequency band, and a reflection coefficient of less than -10 dB is a basic requirement for antennas within this band. An isolation of less than -50 dB is considered very high, and usually, an isolation below -35 dB is sufficient. The horizontal omnidirectional gain of greater than 1.89 dBi is relatively high for an omnidirectional antenna. The difference between the maximum and minimum gain of less than 3 dBi is an indicator for evaluating whether an antenna is omnidirectional (a difference of less than 3 dBi indicates that the antenna meets the omnidirectional requirement, otherwise it does not).

[0038] In this embodiment, as a further optimization, please refer to... Figure 5 A cuboid cavity 201 is provided at the position where the receiving antenna 2 contacts the PCB board 3, which is used to place the chip and ensure the correct transmission of the signal.

[0039] In this embodiment, as a further optimization, please refer to... Figure 1 Both the transmitting antenna 1 and the receiving antenna 2 have eight windows 102, which are arranged in a ring in the recessed area of ​​the cylinder.

[0040] In this embodiment, as a further optimization, please refer to... Figure 1 The baffle 103 is located inside the window 102 and has a gap between it and the coaxial inner conductor 105.

[0041] It should be noted that the main structure of the antenna in this application is a quasi-circular waveguide with multiple uniformly distributed horn-shaped windows on the side. Electromagnetic waves radiate outward from these windows. Because this structure requires the electromagnetic waves within the quasi-circular waveguide to primarily be TM (transient electromagnetic waves). 01 The electromagnetic wave field of this mode points from the center outwards, therefore coaxial feeding is used; the top of the quasi-circular waveguide has an 8-plate baffle structure, TM 01In this configuration, there is no voltage difference on either side of the rectangular window, resulting in weak outward radiation of the electric field. The sloping structure generates a voltage difference on both sides of the horn window, greatly enhancing the radiation capability of the electric field and thus achieving a horizontal omnidirectional radiation pattern. The transmitting and receiving antennas are relatively far apart, and the feed ports on the PCB are isolated by metal vias. The cuboid cavity has a significant impact on the isolation. By rationally arranging the size of the cuboid cavity, high isolation between the transmitting and receiving antennas is achieved. The quasi-circular waveguide structure has a transition section tilted towards the center between itself and the inner conductor of the coaxial line, and the use of a semi-circular waveguide structure are all to meet the structural requirements of 3D printing. The ports of the transmitting and receiving antennas are located at the end of the GCPW structure, which can be directly replaced with BGA-packaged chips for easy connection to the chip. This improves the isolation between the transmitting and receiving antennas, and the unsupported design inside the 3D printed circuit board achieves a horizontally polarized omnidirectional antenna. Furthermore, the loaded PCB structure facilitates the integration of the antenna and the chip, achieving an integrated design.

[0042] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A single-transmitter, single-receiver omnidirectional antenna based on 3D printing technology, characterized in that, include: The PCB board (3) and the transmitting antenna (1) and receiving antenna (2) respectively disposed on both sides of the PCB board (3) have the same structure; The transmitting antenna (1) includes a circular waveguide structure (101), a plurality of windows (102) disposed on the side wall of the circular waveguide structure (101), and a coaxial inner conductor (105), a waveguide transition structure (106), a semi-circular waveguide structure (107) and an L-shaped bending transition structure (108) disposed sequentially within the circular waveguide structure (101). The windows (102) are provided with baffles (103) for extending toward the coaxial inner conductor (105). The window (102) is trumpet-shaped, and the baffle (103) is a cuboid. The baffle (103) is located on the inside of the window (102) and has a gap between it and the coaxial inner conductor (105). The PCB board (3) includes a dielectric layer (306) and a first metal layer (301) and a second metal layer (304) disposed on both sides of the dielectric layer (306). Both the first metal layer (301) and the second metal layer (304) are provided with windows (302). The windows (302) of the first metal layer (301) are aligned with the end of the L-shaped bending conversion structure (108) of the transmitting antenna (1), and the windows (302) of the second metal layer (304) are aligned with the end of the L-shaped bending conversion structure (108) of the receiving antenna (2). The dielectric layer (306) is provided with two SIW to GCPW transition structures (305) respectively connected to the two windows (302). The SIW to GCPW transition structures (305) are surrounded by metallized vias (303).

2. The omnidirectional antenna based on 3D printing technology according to claim 1, characterized in that, The circular waveguide structure (101) is a cylinder with a central indentation, and several windows (102) are arranged in a ring in the recessed area of ​​the cylinder.

3. The omnidirectional antenna based on 3D printing technology according to claim 1, characterized in that, The inner cavity of the quasi-circular waveguide structure (101) is provided with a cylindrical block (104), and the coaxial inner conductor (105) is provided on the cylindrical block (104).

4. The omnidirectional antenna based on 3D printing technology according to claim 1, characterized in that, The waveguide transition structure (106) is inclined toward the axis of the circular waveguide structure (101) and the inclination angle is acute.

5. The omnidirectional antenna based on 3D printing technology for transmitting and receiving, as described in claim 1, is characterized in that... The contact area between the receiving antenna (2) and the PCB board (3) is provided with a cuboid cavity (201).

6. The omnidirectional antenna based on 3D printing technology for transmitting and receiving, as described in claim 1, is characterized in that... The semi-circular waveguide structure (107) is horizontally positioned.

7. The omnidirectional antenna based on 3D printing technology according to claim 1, characterized in that, The end of the inner conductor (105) of the coaxial line extends into the semi-circular waveguide structure (107).

8. The omnidirectional antenna based on 3D printing technology for transmitting and receiving, as described in claim 1, is characterized in that... The transmitting antenna (1) and the receiving antenna (2) are symmetrical about the center position of the PCB board (3) rotated 180°.

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