CN201408840Y - circularly polarized antenna - Google Patents

Abstract

The utility model discloses a circularly polarized antenna, which comprises an antenna substrate, an antenna bottom housing and an antenna dome, wherein the antenna substrate comprises a copper pouredradiating surface at the upper surface, a copper poured feeding network at the lower surface and a dielectric plate in the middle; in the circularly polarized antenna, the copper poured radiating surface is provided with four slot antenna units, wherein the four slot antenna units are symmetrically arranged on the four edges of the copper poured radiating surface, and a slot antenna unit is arranged on each edge; a copper poured feeding network is electrically coupled and connected with a copper poured radiating surface used for feeding for the four slot antenna units, and the feeding through the copper poured feeding network to each slot antenna in the four slot antenna units is equal in amplitude and unequal in phase. According to the technical scheme provided by the utility model, various circularly polarized antennas which can be used for different narrow spaces are provided, therefore, the cost can be reduced, and the requirements of users are met.

Description

circular polarized antenna

technical field

The utility model relates to the field of wireless communication, in particular to a circularly polarized antenna.

Background technique

At present, the radio frequency identification (Radio Frequency Identification, referred to as RFID) industry is developing faster and faster, and it has been widely used in transportation, logistics, monitoring and other fields.

RFID systems include: readers, reader antennas and tags. Among them, the reader transmits the signal to the tag, and the tag reflects the signal to the reader antenna. The above steps form a complete communication link process. When the reader antenna is a circularly polarized antenna, the antenna can effectively read tags placed at different angles and positions. Because the radiation electric field of the circularly polarized antenna is rotating, it can communicate with the linearly polarized antenna in any direction, and the tags are generally linearly polarized, so the reader antenna can communicate well with the tag. In the actual communication process, the positions of tags are often placed irregularly, so circularly polarized antennas are widely used.

RFID technology involves many industries. In some application scenarios with small space, it is necessary to apply a large number of small-sized circularly polarized antennas. At present, there is a lack of ultra-small and low-cost circularly polarized antennas for applications where the application environment is a narrow space to meet user needs.

Utility model content

Aiming at the occasions in the related art where the application environment is a narrow space, and the lack of ultra-small and low-cost circularly polarized antennas, the utility model is proposed. For this reason, the main purpose of the utility model is to provide a circularly polarized antenna to solve the above problems. at least one of the problems.

According to the present invention, a circularly polarized antenna is provided.

The circularly polarized antenna according to the present invention includes: an antenna substrate, an antenna bottom case, and a radome, wherein the antenna substrate includes: a copper-clad radiating surface on the upper surface, a copper-clad feeding network on the lower surface, and a dielectric plate in the middle. In the circularly polarized antenna, the copper-clad radiating surface has four unit slot antennas, among which, the four unit slot antennas are symmetrically arranged on the four edges of the copper-clad radiating surface, and each edge is provided with a unit slot antenna; the copper-clad feed The network is electrically coupled and connected to the copper-clad radiating surface, and is used to feed the four unit slot antennas. The copper-clad feed network feeds each slot antenna in the four unit slot antennas with equal amplitude and unequal phase .

Preferably, the copper-clad feeding network includes four branches, wherein the four branches are electrically coupled and connected to the four unit slot antennas one by one, and each branch is used to feed the unit slot antenna connected to it.

Preferably, each branch is connected in series with at least one capacitor, wherein the capacitor is used to adjust the feed phase of the branch connected in series.

Preferably, the above-mentioned copper-clad feed network is connected to a coaxial line, the co-axial line is electrically coupled and connected to the copper-clad radiating surface, and the copper-clad feed network is used to electrically couple and feed circularly polarized antennas through the coaxial line .

Preferably, the copper-clad feed network and the coaxial cable are connected in the following manner: the outer skin of the co-axial cable is welded with the copper-clad wire on one side of the copper-clad feed network, and the core wire of the coaxial cable is connected to the copper-clad feed network The other side of the copper wire solder connection.

Preferably, the above-mentioned antenna substrate adopts a high-frequency plate.

Preferably, the antenna bottom case is made of conductive metal material.

Preferably, the four corners of the antenna bottom case are provided with metal posts, and the metal posts are used to fix the antenna bottom case and the antenna substrate.

Preferably, the aforementioned radome is made of glass fiber reinforced plastic.

Preferably, the length and width of the above-mentioned circularly polarized antenna are both 0.25 wavelengths, and the height is 0.07 wavelengths.

Through the utility model, a circularly polarized antenna with ultra-small size and low manufacturing cost is provided, which solves the problem of lack of ultra-small and low-cost circularly polarized antennas in the related art, and further provides a circularly polarized antenna that can be used in various narrow spaces. Circularly polarized antennas can reduce costs and meet user needs.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the utility model and constitute a part of the application. The schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. In the attached picture:

1 is a top view of a circularly polarized antenna according to an embodiment of the present invention;

2 is a top view of the copper-clad radiation surface of the circularly polarized antenna according to an embodiment of the present invention;

3 is a top view of a copper-clad feed network of a circularly polarized antenna according to an embodiment of the present invention;

Fig. 4 is a top view of a circularly polarized antenna according to a preferred embodiment of the present invention.

Detailed ways

Functional Overview

Considering the lack of ultra-small and low-cost circularly polarized antennas in the related art when the application environment is a narrow space, the embodiments of the present invention provide a circularly polarized antenna with ultra-small size and low manufacturing cost. The copper-clad radiating surface on the upper surface of the antenna substrate of the circularly polarized antenna has four unit slot antennas, wherein the above-mentioned four unit slot antennas are symmetrically arranged on the four edges of the copper-clad radiating surface, and each edge is provided with a unit slot antenna. The symmetrical slot distribution method is used to achieve equal amplitude feeding of the four-element slot antenna, and the radiation mode of the four-element slot antenna is used to adjust the impedance to a suitable area, which effectively solves the problem of unsatisfactory impedance caused by the small size and space. The copper-clad feed network on the lower surface of the antenna substrate is electrically coupled and connected to the copper-clad radiating surface, and is used to feed the above-mentioned four unit slot antennas, wherein the copper-clad feed network feeds each slot in the four unit slot antennas The feeds from the antennas are equal in amplitude and unequal in phase. The phase difference between every two adjacent slot antennas is 90 degrees.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

FIG. 1 is a top view of a circularly polarized antenna according to an embodiment of the present invention. As shown in FIG. 1 , a circularly polarized antenna according to an embodiment of the present invention includes: an antenna substrate, an antenna bottom case, a radome, and a connecting feeder. Wherein, the above-mentioned antenna substrate includes: a copper-clad radiating surface on the upper surface, a copper-clad feeding network on the lower surface, and a dielectric board in the middle.

Preferably, the copper-clad radiating surface has four unit slot antennas, wherein the four unit slot antennas are symmetrically arranged on four edges of the copper-clad radiating surface, and one unit slot antenna is arranged on each edge, see FIG. 2 for details.

Fig. 2 is a top view of a copper-clad radiation surface of a circularly polarized antenna according to an embodiment of the present invention. As shown in FIG. 2 , four slots are arranged in the middle of the above-mentioned copper-clad radiation surface, and the four slots are distributed at symmetrical positions of the above-mentioned copper-clad radiation surface, forming four unit slot antennas. The above four unit slot antennas are slot antenna 20 , slot antenna 22 , slot antenna 24 and slot antenna 26 , wherein the four unit slot antennas are arranged symmetrically on the four edges of the copper-clad radiating surface.

In the specific implementation process, a symmetrical slot distribution mode is used to make the above four unit slot antennas 20, 22, 24, 26 achieve equal amplitude feeding; for small-sized antennas, the impedance bandwidth of the antenna is small, and the impedance matching Not ideal, so slit radiation is used to adjust the impedance to a suitable area.

Wherein, adjusting the impedance to a suitable area by means of slit radiation may include but not limited to the following methods: adjusting the impedance to a suitable area by adjusting the length and width of four symmetrical slits, and/or adjusting the four symmetrical slits The location of the slit adjusts the impedance to the appropriate area.

Through this embodiment, the defect that the impedance is very poor and difficult to match when the conventional dipole mode is adopted can be overcome. Using the four-element slot antenna method, the impedance is better, and it is easy to match, which can achieve better results.

Preferably, the copper-clad feeding network is electrically coupled and connected to the copper-clad radiating surface, and is used to feed the four unit slot antennas, wherein the copper-clad feeding network feeds each slot antenna in the four unit slot antennas. The electrical amplitudes are equal and the phases are unequal, see Figure 3 for details.

Fig. 3 is a top view of a copper-clad feeding network of a circularly polarized antenna according to an embodiment of the present invention. As shown in FIG. 3 , the copper-clad feeding network includes four branches 30 , 32 , 34 , and 36 . The four unit slot antennas in Fig. 2 are fed respectively, that is, the branch 30 feeds the slot antenna 20, the branch 32 feeds the slot antenna 22, the branch 34 feeds the slot antenna 24, and the branch 36 feeds the slot antenna 26 for feeding.

In the specific implementation process, the four unit slot antennas can be fed with equal amplitude and different phases by connecting capacitors in series on the copper feeding network, that is, each branch is connected in series with at least one capacitor, where the capacitor is used It is used to adjust the feed phase of the branches connected in series. The phase difference between every two adjacent slot antennas can be 90 degrees, thereby realizing circular polarization.

Through this embodiment, the above-mentioned copper-clad feeding network can realize the difference in the phase shift of the above-mentioned slot antenna, and better realize the effect of circular polarization.

Preferably, the above-mentioned copper-clad feed network is connected to a coaxial cable, and the co-axial cable is electrically coupled and connected to the copper-clad radiating surface, and the copper-clad feed network is used to electrically couple and feed circularly polarized antennas through the coaxial cable .

Preferably, the connection method between the above-mentioned copper-clad feed network and the above-mentioned coaxial line includes but is not limited to: the sheath of the co-axial line is welded with the copper-clad wire on one side of the copper-clad feed network, and the core wire of the coaxial line is connected to the coaxial line. The other side of the copper feed network is laid with copper wires for soldering connection.

Preferably, the above-mentioned antenna substrate can use common high-frequency boards. For example, use a FR4 plate with a lower cost of 0.25 wavelength, a thickness of 1mm, and a dielectric constant of 4.4. Because the application frequency of RFID is low, ordinary FR4 plates can be used, which can save costs.

Preferably, the above antenna bottom case can be made of a metal material with good electrical conductivity. For example, aluminum alloy material.

Preferably, the four corners of the antenna bottom case are provided with metal posts, and the metal posts are used to fix the antenna bottom case and the antenna substrate.

Preferably, the aforementioned radome is made of glass fiber reinforced plastic.

Preferably, the length and width of the circularly polarized antenna are 0.25 wavelengths, and the height is 0.07 wavelengths.

Fig. 4 is a top view of a circularly polarized antenna according to a preferred embodiment of the present invention. As shown in FIG. 4 , the circularly polarized antenna can also be connected with an N-type connector for connecting with a reader in the RFID system to receive signals reflected from tags in the RFID system.

Through the above embodiments, an antenna gain of more than 2dB, an axial ratio of less than 2dB, and a standing wave ratio of less than 1.2 can be achieved. Small size and stable performance.

In summary, through the above embodiments of the present invention, a circularly polarized antenna that can be used in various narrow spaces is provided, which solves the problem of lack of ultra-small and low-cost circularly polarized antennas in the related art. The circularly polarized antenna provided by the utility model has stable performance, is easy to process in batches, and is convenient to install. Thereby, the cost can be reduced and the needs of users can be better met.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned utility model can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed among multiple computing devices. Optionally, they can be implemented with executable program codes of computing devices, thus, they can be stored in storage devices and executed by computing devices, or they can be made into individual integrated circuit modules, or they can be A plurality of modules or steps in the process are realized by making a single integrated circuit module. As such, the invention is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (10)

1. a circular polarized antenna comprises antenna substrate, antenna drain pan, radome, and wherein, described antenna substrate comprises: the shop copper radiation face of upper surface, the shop copper feeding network of lower surface and middle dielectric-slab, it is characterized in that,

Described shop copper radiation mask has four unit interstices antennas, wherein, is arranged on to described four unit interstices antenna symmetry four edges of described shop copper radiation face, and each edge is provided with a unit interstices antenna;

Described shop copper feeding network is connected with the copper radiation face electric coupling of described shop, be used for described four unit interstices antennas are carried out feed, wherein, described shop copper feeding network to the feed amplitude that each slot antenna in described four unit interstices antennas carries out equate, phase place is unequal.

2. circular polarized antenna according to claim 1, it is characterized in that described shop copper feeding network comprises four branches, wherein, described four branches are connected with described four unit interstices antenna electric coupling correspondingly, and each branch is used for connected unit interstices antenna is carried out feed.

3. circular polarized antenna according to claim 2 is characterized in that, described each branch and at least one capacitances in series, and wherein, described electric capacity is used to regulate the current feed phase of the branch of series connection with it.

4. circular polarized antenna according to claim 1, it is characterized in that, described shop copper feeding network is connected with coaxial line, and described coaxial line is connected with the copper radiation face electric coupling of described shop, and described shop copper feeding network is used for carrying out the electric coupling feed by the described circular polarized antenna of described coaxial pair.

5. circular polarized antenna according to claim 4 is characterized in that, described shop copper feeding network is connected in the following manner with described coaxial line:

The one side shop copper cash of the crust of described coaxial line and described shop copper feeding network is welded to connect, and the opposite side shop copper cash of the heart yearn of described coaxial line and described shop copper feeding network is welded to connect.

6. according to each described circular polarized antenna in the claim 1 to 5, it is characterized in that described antenna substrate adopts high frequency sheet material.

7. according to each described circular polarized antenna in the claim 1 to 5, it is characterized in that described antenna drain pan adopts conductive metallic material.

8. according to each described circular polarized antenna in the claim 1 to 5, it is characterized in that four angles of described antenna drain pan are provided with metal column, described metal column is used for described antenna drain pan and described antenna substrate are fixed.

9. according to each described circular polarized antenna in the claim 1 to 5, it is characterized in that described radome adopts glass-reinforced plastic material.

10. according to each described circular polarized antenna in the claim 1 to 5, it is characterized in that the length of described circular polarized antenna and wide 0.25 wavelength that is highly are 0.07 wavelength.

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