CN209766654U - Circularly polarized microstrip flat antenna - Google Patents

Abstract

The utility model discloses a circularly polarized microstrip flat panel antenna, which belongs to the field of antennas and comprises a microstrip array antenna, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a first metal layer, a second metal layer, Third metal, layer waveguide layer, microstrip-waveguide transition. The microstrip array antenna includes N antenna elements with the same structure, and each antenna element includes four identical metal rectangular patches. The metal patch and the first dielectric substrate are provided with vertical metal through holes; the antenna of the utility model realizes the different-plane structure of the antenna and the active device, reduces the loss and interference of the feeder line, and reduces the influence of the active network on the antenna , has the advantages of small size, low cost, high gain, high isolation and so on.

Description

A Circularly Polarized Microstrip Panel Antenna

technical field

The utility model belongs to the field of antennas, in particular to a circularly polarized microstrip planar antenna used in vehicle-mounted radars.

Background technique

According to the polarization characteristics, antennas can be divided into three types: linear polarization, circular polarization and elliptical polarization, among which linear polarization antennas are the most widely used. Compared with linearly polarized antennas, circularly polarized antennas have the advantages of anti-interference, anti-rain and fog, and anti-attenuation, and there is no need to meet strict directivity between transmitting and receiving antennas. These advantages make the research on circularly polarized antennas get people's great attention.

Compared with other forms of antennas, microstrip array antennas are widely used due to their low profile, small size, easy conformability, and easy acquisition of circular polarization characteristics. The principle of realizing microstrip circular polarization is to excite two linearly polarized waves with orthogonal polarization directions, equal amplitude, and 90° phase difference between the radiation patch and the reflector. The single feed point method has an axial ratio bandwidth The shortcoming of being narrow, the feeding network structure of the multi-feed point method is complex, and the loss is large in the high frequency band, so the existing technology still needs to be improved and developed.

Utility model content

The technical problem solved by the utility model is to provide a circularly polarized microstrip panel antenna with the advantages of high gain, small volume, high transceiver isolation, low cost, stability and reliability.

The technical solution to realize the purpose of this utility model is: a circularly polarized microstrip panel antenna, which has a microstrip array antenna, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a first metal layer, a second metal Layer, third metal layer, waveguide layer, microstrip line-waveguide transition, power splitter.

The first dielectric substrate, the first metal layer, the second dielectric substrate, the second metal layer, the waveguide layer, the third metal layer, and the third dielectric substrate are stacked sequentially from top to bottom, and the first dielectric substrate is far away from the first metal substrate. A microstrip array antenna is arranged on one side of the layer, a vertical metal through hole is arranged on the microstrip array antenna and the first dielectric substrate, and a gap is arranged on the first metal layer; a metallized through hole is arranged on the second dielectric substrate to form a splitter, A gap is set on the second metal layer; a ground plate and a feeder line are set on the side of the third dielectric substrate away from the third metal layer;

The microstrip-waveguide transition includes a ground plate, a third dielectric substrate, a third metal layer and a radiation patch.

The third dielectric substrate and the waveguide layer perform energy transmission through the radiation patch of the microstrip line-waveguide transition, the second dielectric substrate and the waveguide layer perform energy transmission through the gap set on the second metal layer, the microstrip array antenna and the first The dielectric substrate transmits energy through the gaps provided on the first metal layer.

Further, the microstrip array antenna includes N antenna units with the same structure.

Further, each antenna unit in the microstrip array antenna includes 4 identical metal rectangular patches, and the 4 patches are distributed in pairs at equal intervals, with a spacing of 1, and a pair of patches in the diagonal position connected by metal strips;

Further, each patch of the antenna unit and the first dielectric substrate are provided with a vertical metal through hole.

Compared with the prior art, the utility model has the remarkable advantages that: by connecting the microstrip line-waveguide transition device with the waveguide, the different-plane structure of the antenna and the active device is realized, the loss and interference of the feeder line are reduced, and the The influence of the active network on the antenna; the square microstrip patch is used, and the structure is improved to achieve a high-gain, high-isolation antenna structure in a limited volume, which has the advantages of low cost, small size, and high performance.

Description of drawings

Fig. 1 is a three-dimensional perspective view of a circularly polarized microstrip planar antenna of the present invention.

Fig. 2 is a schematic cross-sectional structure diagram of the circularly polarized microstrip planar antenna of the present invention.

Fig. 3 is a detailed structural diagram of the circularly polarized microstrip panel antenna of the present invention. Wherein, figure (a) is the structure of the microstrip array antenna 1 above the first dielectric substrate (S1), figure (b) is the structure on the first dielectric substrate (S1), and figure (c) is the first metal layer ( The structure on M1), the figure (d) is the structure on the second dielectric substrate (S2), the figure (e) is the structure on the second metal layer (M2), and the figure (f) is the structure of the waveguide layer (2) , Figure (g) is the structure on the third metal layer (M3), Figure (h) is the structure on the third dielectric substrate (S3), and Figure (i) is the microstrip feeder under the third dielectric substrate (S3) structure.

Fig. 4 is a detailed structure diagram of the microstrip line-waveguide transition (T) of the circularly polarized microstrip planar antenna of the present invention.

FIG. 5 is a schematic diagram of the parameters of any antenna unit of the circularly polarized microstrip panel antenna in the embodiment of the present invention.

Fig. 6 is a three-dimensional beam pattern of the circularly polarized microstrip panel antenna in the embodiment of the present invention.

Fig. 7 is a two-dimensional beam pattern of the circularly polarized microstrip panel antenna in the embodiment of the present invention.

Fig. 8 is an axial ratio diagram of the circularly polarized microstrip planar antenna in the embodiment of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Combined with Fig. 1 and Fig. 2, a circularly polarized microstrip panel antenna of the present invention has a microstrip array antenna 1, a first dielectric substrate S1, a second dielectric substrate S2, a third dielectric substrate S3, and a first metal layer M1 , the second metal layer M2, the third metal layer M3, the waveguide layer 2, the microstrip line-waveguide transition T, and the power divider D.

Referring to FIG. 3, the first dielectric substrate S1, the first metal layer M1, the second dielectric substrate S2, the second metal layer M2, the waveguide layer 2, the third metal layer M3, and the third dielectric substrate S3 are stacked sequentially from top to bottom, A microstrip array antenna 1 is provided on the side of the first dielectric substrate S1 far away from the first metal layer M1, a vertical metal through hole is provided on the microstrip array antenna 1 and the first dielectric substrate S1, and a slit is provided on the first metal layer M1; A metallized through hole is provided on the second dielectric substrate to form a divider D, and a gap is provided on the second metal layer M2; a ground plate G and a feeder line are provided on the side of the third dielectric substrate S3 away from the third metal layer M3.

Referring to FIG. 4 , the microstrip-waveguide transition T2 includes a ground plate G, a third dielectric substrate S3 , a third metal layer M3 and a radiation patch P.

The third dielectric substrate S3 and the waveguide layer 2 perform energy transmission through the radiation patch P of the microstrip line-waveguide transition T, and the second dielectric substrate S2 and the waveguide layer 2 perform energy transmission through the gap provided on the second metal layer M2, The microstrip array antenna 1 and the first dielectric substrate S1 perform energy transmission through the gap provided on the first metal layer M1.

Further, the microstrip array antenna 1 includes N antenna units with the same structure.

Further, each antenna unit in the microstrip array antenna 1 includes 4 identical metal rectangular patches, and the 4 patches are equally spaced in pairs with a spacing of 1, and a pair of patches in the diagonal position pass through connected by metal strips;

Further, each patch of the antenna unit and the first dielectric substrate S1 are provided with a vertical metal through hole.

Preferably, N=4, l=0.05mm˜0.15mm.

Preferably, the model of the first dielectric substrate S1 , the second dielectric substrate S2 and the third dielectric substrate S3 is Rogers3003, and the thickness thereof is 127 μm.

Preferably, the materials of the microstrip array antenna 1, the first metal layer M1, the second metal layer M2, the third metal layer M3 and the inner wall of the square hole of the waveguide layer 2 are copper; the microstrip array antenna 1, the first The thickness of the metal layer M1 , the second metal layer M2 and the third metal layer M3 is 18 μm, and the height of the waveguide layer 2 is 0.5 mm˜2 mm.

Preferably, the diameter of the through hole of the microstrip line-waveguide transition T is 0.15-0.3mm, and the distance between the through holes is 0.2mm-0.4mm; the diameter of the through-hole of the power divider D is 0.3-0.5mm, and the distance between the through holes The diameter of the through hole on the microstrip array antenna 1 and the first dielectric substrate S1 is 0.2-0.3 mm.

Below in conjunction with specific embodiment the utility model is described in further detail.

Example

The central frequency of the antenna in the embodiment of the present invention is 77GHz.

Referring to FIG. 1 , FIG. 2 and FIG. 4 , the diameter of the through hole in the microstrip line-waveguide transition T in this embodiment is 0.2 mm, and the distance between the through holes is 0.33 mm. The diameter of the through holes in the power divider D is 0.4 mm, and the distance between the through holes is 0.6 mm. The diameter of the through hole on the microstrip array antenna 1 and the first dielectric substrate S1 is 0.25mm.

In conjunction with Fig. 1, Fig. 2 and Fig. 5, the specific parameters of each antenna element in the microstrip array antenna 1 in the present embodiment are as follows: a1=a2=0.8mm, b1=b2=0.09mm, c1=0.71mm, c2= 0.75mm, d=0.1mm.

The length of the square hole of the first metal layer M1 in the present embodiment is 1.5mm, and the width is 0.24mm; The length of the square hole of the M2 of the second metal layer is 1mm, and the width is 0.75mm; The square hole of the third metal layer M3 The length is 2.54mm and the width is 1.27mm.

Referring to FIG. 3 c , in this embodiment, the radiation patch placed in the center of the square hole in the third metal layer M3 has a length of 2.1 mm and a width of 0.9 mm.

The microstrip array antenna of the present invention is simulated to test the isolation of the transmitting and receiving antennas. The simulation results show that the isolation of the antenna can reach 68dB at a frequency of 77GHz.

6 and 7, it can be seen that in this embodiment, the gain of the antenna is 11dB, the 3dB beamwidth is about 26°, the main-sidelobe ratio is greater than 13dB, and the maximum sidelobe level appears at theta=66°; combined with FIG. 8 It can be seen that the axial ratio of the antenna to the 3dB beamwidth is about ±18°.

In summary, the antenna of the utility model realizes the different-plane structure of the antenna and the active device, reduces the loss and interference of the feeder line, reduces the influence of the active network on the antenna, and can effectively suppress the side lobe through the metal patch, which has the advantages of Small size, low cost, high gain, low sidelobe, high isolation and other advantages.

Claims (8)

1. A circularly polarized microstrip flat antenna is characterized by comprising a microstrip array antenna (1), a first dielectric substrate (S1), a second dielectric substrate (S2), a third dielectric substrate (S3), a first metal layer (M1), a second metal layer (M2), a third metal layer (M3), a waveguide layer (2), a microstrip line-waveguide transition device (T) and a power divider (D);

The microstrip array antenna comprises a first dielectric substrate (S1), a first metal layer (M1), a second dielectric substrate (S2), a second metal layer (M2), a waveguide layer (2), a third metal layer (M3) and a third dielectric substrate (S3), wherein the first dielectric substrate (S1) is sequentially overlapped from top to bottom, a microstrip array antenna (1) is arranged on one side, far away from the first metal layer (M1), of the first dielectric substrate (S1), vertical metal through holes are formed in the microstrip array antenna (1) and the first dielectric substrate (S1), and a gap is formed in the first metal layer (M1); a metallized through hole is arranged on the second dielectric substrate to form a power divider (D), and a gap is arranged on the second metal layer (M2); a grounding plate (G) and a feeder line are arranged on one side of the third dielectric substrate (S3) far away from the third metal layer (M3);

The microstrip line-waveguide transition device (T) comprises a ground plate (G), a third dielectric substrate (S3), a third metal layer (M3) and a radiation patch (P);

The third dielectric substrate (S3) and the waveguide layer (2) carry out energy transmission through a radiation patch (P) of the microstrip line-waveguide transition device (T), the second dielectric substrate (S2) and the waveguide layer (2) carry out energy transmission through a gap arranged on the second metal layer (M2), and the microstrip array antenna (1) and the first dielectric substrate (S1) carry out energy transmission through a gap arranged on the first metal layer (M1).

2. The circularly polarized microstrip panel antenna according to claim 1, characterized in that the microstrip array antenna (1) has N antenna elements of identical structure.

3. The circularly polarized microstrip panel antenna according to claim 2, wherein each antenna element of the microstrip array antenna (1) has 4 identical rectangular metal patches, 4 patches are distributed with equal spacing between each two patches, and the spacing is l, wherein a pair of patches at diagonal positions are connected by a metal strip.

4. the circularly polarized microstrip patch antenna according to claim 2 or 3, wherein each of the patches of the antenna element and the first dielectric substrate (S1) is provided with a vertical metal via.

5. The microstrip patch antenna according to claim 2 or 3, wherein N is 4 and l is 0.05mm to 0.15 mm.

6. The circularly polarized microstrip patch antenna according to claim 1, wherein the first dielectric substrate (S1), the second dielectric substrate (S2) and the third dielectric substrate (S3) have a dielectric constant of 3.04 and a thickness of 127 μm.

7. The circularly polarized microstrip patch antenna according to claim 1, wherein the microstrip array antenna (1), the first metal layer (M1), the second metal layer (M2), the third metal layer (M3) and the inner wall of the square hole of the waveguide layer (2) are all made of copper; the thickness of the microstrip array antenna (1), the first metal layer (M1), the second metal layer (M2) and the third metal layer (M3) is 18 microns, and the height of the waveguide layer (2) is 0.5 mm-2 mm.

8. The circularly polarized microstrip panel antenna according to claim 1, wherein the microstrip line-waveguide transition (T) has a via diameter of 0.15 to 0.3mm and a via-to-via spacing of 0.2 to 0.4 mm; the diameter of each through hole of the power divider (D) is 0.3-0.5 mm, and the distance between the through holes is 0.5-0.7 mm; the diameter of the through holes on the microstrip array antenna (1) and the first dielectric substrate (S1) is 0.2-0.3 mm.