CN-122026087-A - Filtering circularly polarized antenna with wide axial ratio bandwidth

CN122026087ACN 122026087 ACN122026087 ACN 122026087ACN-122026087-A

Abstract

The invention provides a filtering circularly polarized antenna with a wide axial ratio bandwidth, which comprises a first dielectric plate, a second dielectric plate, a third dielectric plate and a fourth dielectric plate which are sequentially arranged in parallel from bottom to top, wherein a metal reflecting plate is printed on the lower surface of the first dielectric plate, a feed network is printed on the lower surface of the second dielectric plate, slotted metal ground is printed on the upper surface of the second dielectric plate, a feed port is arranged on one side edge of the second dielectric plate, the feed port is electrically connected with the feed network and the slotted metal, a second square patch and an octagonal parasitic microstrip line frame are printed on the upper surface of the third dielectric plate, the octagonal parasitic microstrip line frame surrounds the outer side of the second square patch, and a first square patch is printed on the lower surface of the fourth dielectric plate. The invention realizes the characteristics of 2.3-5.0GHz broadband circular polarization radiation and high gain through interlayer coupling collaborative design, has high out-of-band rejection capability, and can effectively filter out-of-band clutter interference.

Inventors

JIANG HUAN
LAI JIAWEI
YE LIANGHUA

Assignees

广东工业大学

Dates

Publication Date: 20260512
Application Date: 20260401

Claims (7)

1. The filtering circularly polarized antenna with the wide axial ratio bandwidth is characterized by comprising a first dielectric plate, a second dielectric plate, a third dielectric plate and a fourth dielectric plate which are sequentially arranged in parallel from bottom to top; The lower surface of the second dielectric plate is printed with a feed network, the upper surface of the second dielectric plate is printed with slotted metal ground, one side edge of the second dielectric plate is provided with a feed port, the feed port is electrically connected with the feed network and the slotted metal ground and used for feeding power to the feed network and the slotted metal ground, the upper surface of the third dielectric plate is printed with a second square patch and an octagonal parasitic microstrip line frame, and the octagonal parasitic microstrip line frame surrounds the outer side of the second square patch; The slit metal ground is a metal copper plate which completely covers the upper surface of the second dielectric plate, and a slit pattern in a central symmetry pattern is arranged on the slit metal ground, wherein the slit pattern comprises square slit units, main shaft slit units, first branch slit units, second branch slit units, third branch slit units, fourth branch slit units, fifth branch slit units, sixth branch slit units, first bending slit units and second bending slit units which are mutually communicated into a whole; The square gap unit is arranged in the middle of the slotted metal ground, the center of the square gap unit is the center of the whole gap pattern, the main shaft gap unit is arranged along the central axis of the square gap unit, the middle point of the main shaft gap unit coincides with the center of the square gap unit, two ends of the main shaft gap unit respectively vertically cross with two opposite side edges of the square gap unit and then extend to the outer side of the square gap unit, one end of the first branch gap unit is vertically connected to one third of the main shaft gap unit, the other end of the first branch gap unit vertically cross with the side edge of the square gap unit and then extend to the outer side of the square gap unit, the second branch gap unit is arranged at the outer side of the square gap unit and is parallel to the main shaft gap unit, the middle part of the second branch gap unit is vertically connected to the other end of the first branch gap unit, the third branch gap unit is parallel to the main shaft gap unit and vertically cross with the first branch gap unit, one end of the third branch gap unit vertically cross with the side edge of the square gap unit and then extends to the outer side of the square gap unit, and the other end of the third branch gap unit is positioned at the inner side of the square gap unit and vertically cross with the side edge of the first bending gap unit; The fourth branch slit unit and the first branch slit unit are arranged in 180-degree rotation symmetry, the fifth branch slit unit and the second branch slit unit are arranged in 180-degree rotation symmetry, the sixth branch slit unit and the third branch slit unit are arranged in 180-degree rotation symmetry, and the second bending slit unit and the first bending slit unit are arranged in 180-degree rotation symmetry; The feed network comprises a transmission microstrip line, a U-shaped microstrip line, a rectangular microstrip line frame and four diagonal microstrip lines, wherein the rectangular microstrip line frame is arranged in the middle of the lower surface of the second dielectric plate, the center of the rectangular microstrip line frame is aligned with the center of a square gap unit in the slotted metal ground, the inner sides of the four corners of the rectangular microstrip line frame are respectively connected with one diagonal microstrip line, one end of each diagonal microstrip line is respectively connected with the side edge of the rectangular microstrip line frame at an angle of 45 degrees, the other end of each diagonal microstrip line is respectively arranged towards the center of the rectangular microstrip line frame, the transmission microstrip line is integrally L-shaped and comprises a main body section and a bending section which are vertically connected, the main body section is arranged along the central axis of the rectangular microstrip line frame and is vertical to the main shaft gap unit in the slotted metal ground, one end of the main body section is arranged at one side edge of the second dielectric plate and is connected with a feed port on the side edge of the second dielectric plate, and the other end of the main body section penetrates the whole rectangular microstrip line frame and is vertically connected with the bending section; the U-shaped microstrip line is arranged near the side edge close to the feed port and comprises a bottom edge section and two parallel sections, the bottom edge section is perpendicularly and cross-connected with the main body section of the transmission microstrip line, the two parallel sections are respectively arranged at two sides of the main body section of the transmission microstrip line and are respectively and perpendicularly connected with two ends of the bottom edge section, and the tail ends of the two parallel sections respectively extend to the side edge where the feed port is located.
2. The filtered circularly polarized antenna with wide axial ratio bandwidth of claim 1, wherein the centers of the first square patch, the second square patch and the octagonal parasitic microstrip line frame are all aligned with the center of the square slot element, and the side length of the second square patch is greater than the side length of the first square patch.
3. The filtered circularly polarized antenna with wide axial ratio bandwidth of claim 1, wherein the second dielectric plate is disposed 11.2mm above the first dielectric plate, the third dielectric plate is disposed 5.5mm above the second dielectric plate, and the fourth dielectric plate is disposed 10.1mm above the third dielectric plate.
4. The filtered circularly polarized antenna with wide axial ratio bandwidth of claim 3 wherein the dielectric constants of the first, second, third and fourth dielectric plates are 2.6 and 1.524mm thick.
5. The circular polarized filter antenna with wide axial ratio bandwidth according to claim 1, wherein the first dielectric plate, the second dielectric plate, the third dielectric plate and the fourth dielectric plate are square, wherein the side length of the first dielectric plate is 130mm, the side length of the second dielectric plate is 45.4mm, the side length of the third dielectric plate and the side length of the fourth dielectric plate are 84mm, the slit metal is completely covered on the upper surface of the second dielectric plate, the side length of the slit metal is equal to that of the second dielectric plate, and the metal reflecting plate is completely covered on the lower surface of the first dielectric plate, and the side length of the metal reflecting plate is equal to that of the first dielectric plate.
6. The filtering circular polarized antenna with wide axial ratio bandwidth according to claim 1, wherein in the slit pattern of the slit metal, the length of the main axis slit unit is 22.3mm, the width is 0.76mm, the side length of the square slit unit is 18.9mm, the width is 0.3mm, the length of the first branch slit unit and the fourth branch slit unit is 13.4mm, the width is 0.76mm, the length of the second branch slit unit and the fifth branch slit unit is 14.8mm, the width is 0.76mm, the length of the third branch slit unit and the sixth branch slit unit is 16.9mm, the width is 0.76mm, the length of the first bending slit unit and the second bending slit unit is 2mm, and the width is 0.76mm.
7. The filtering circularly polarized antenna with wide axial ratio bandwidth according to claim 6, wherein in the feed network, the length of the main section of the transmission microstrip line is 29.2mm, the width is 4.5mm, the length of the bending section of the transmission microstrip line is 9mm, the width is 2.6mm, the side length of the rectangular microstrip frame is 10.8mm, the length of the diagonal microstrip line is 3mm, the width is 0.8mm, the length of the bottom section of the U-shaped microstrip line is 7mm, the length of the parallel section is 4mm, and the width is 1mm.

Description

Filtering circularly polarized antenna with wide axial ratio bandwidth Technical Field The invention relates to the field of communication antennas, in particular to a filtering circularly polarized antenna with wide axial ratio bandwidth. Background Modern 5G, satellite communications, and other new generation communication systems place multiple stringent demands on antenna performance. Specifically, the antenna needs to cover multiple application frequency bands such as 2.3-5GHz to realize broadband radiation, has a wide axial ratio bandwidth to ensure stable circular polarization characteristics, has strong out-of-band rejection capability to filter clutter interference, and simultaneously needs to meet the structural requirements of miniaturization and integration of equipment. However, the prior art antenna has difficulty in meeting the above requirements. For example, the bandwidth of the traditional broadband circularly polarized antenna is expanded by a single radiation structure, the out-of-band suppression capability of the traditional broadband circularly polarized antenna is weak and is easy to be interfered by external signals, the antenna with the filtering function is insufficient in coupling design of the filtering and radiation structures, the axial ratio bandwidth and the radiation efficiency are sacrificed when the out-of-band suppression is realized, in addition, the frequency band overlapping and the polarization purity reduction are caused by unreasonable interlayer electromagnetic coupling of part of the multi-layer structure antenna, and in addition, the antenna depends on complex feed or the radiation structure to realize functional integration, so that the processing difficulty is improved. In summary, in the 2.3-5GHz critical frequency band, the existing antenna cannot realize continuous wide-axis-ratio bandwidth coverage, has poor out-of-band interference isolation effect, and is difficult to adapt to the use requirements of 5G and satellite communication on high-performance antennas. Therefore, developing a filtering circularly polarized antenna with wide axial ratio bandwidth, high out-of-band rejection and excellent radiation performance becomes a key to breaking through the performance bottleneck of the current communication system antenna. Disclosure of Invention The invention aims to overcome the defects in the prior art and provide a filtering circularly polarized antenna with wide axial ratio bandwidth, which has the advantages of wide axial ratio bandwidth and high gain and can realize the filtering function without introducing an additional filtering network. In order to achieve the above purpose, the present invention adopts the following technical scheme: the filter circularly polarized antenna with wide axial ratio bandwidth provided by the invention realizes the characteristics of 2.3-5.0GHz broadband circularly polarized radiation and high gain through interlayer coupling collaborative design, has high out-of-band rejection capability, can effectively filter out-of-band clutter interference, and can be widely applied to communication systems requiring miniaturized high-performance antennas such as 5G and satellite communication. Drawings Fig. 1 is an exploded view of a structure of a filtered circularly polarized antenna with a wide axial ratio bandwidth according to an embodiment of the present invention. Fig. 2 is a schematic diagram of the upper surface structure of a second dielectric plate in an embodiment of the present invention. Fig. 3 is a schematic view of the lower surface structure of the second dielectric plate in the embodiment of the present invention. Fig. 4 is a schematic view of the upper surface structure of a third dielectric plate in an embodiment of the present invention. FIG. 5 is a graph showing the reflection coefficient S11 versus frequency for an embodiment of the present invention in a simulated state. FIG. 6 is a graph of axial ratio versus frequency results for an embodiment of the present invention in a simulated state. Fig. 7 is a graph of gain versus frequency results for an embodiment of the present invention in a simulated state. FIG. 8 is a graph of efficiency versus frequency results for an embodiment of the present invention in a simulated state. FIG. 9 is a chart of the XOZ plane at a frequency of 3.7GHz in accordance with an embodiment of the present invention. FIG. 10 is a YOZ-plane pattern at a frequency of 3.7GHz for an embodiment of the invention. Detailed Description The technical scheme of the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. As shown in fig. 1, the filtering circularly polarized antenna with wide axial ratio bandwidth provided by the embodiment of the invention comprises a first dielectric plate 11, a second dielectric plate 12, a third dielectric plate 13 and a fourth dielectric plate 14 which are sequentially arranged in parallel from b