KR-20260065228-A - Circularly polarized antenna for RFID reader in UHF band
Abstract
The present invention relates to an antenna for an RFID reader, and more specifically, to a circularly polarized antenna for a UHF band RFID reader that generates circular polarization with a resonant frequency in the UHF band. In addition, it includes a dielectric substrate having a predetermined dielectric constant formed to allow a metal plate to be mounted on the upper surface, a grounding substrate formed to allow the dielectric substrate to be laminated on the upper surface, a radiation patch formed on the upper surface of the dielectric substrate having a rectangular structure with two diagonal corners of the rectangular corners removed to generate circular polarization, and a power supply unit that supplies power to the radiation patch by penetrating the grounding substrate and the dielectric substrate.
Inventors
- 정유정
- 임태균
- 곽호성
- 서상혁
Assignees
- 제일기술(주)
Dates
- Publication Date
- 20260508
- Application Date
- 20241101
Claims (5)
- A dielectric substrate formed to mount a metal plate on its upper surface and having a predetermined dielectric constant; and A grounding substrate having a grounding plane and formed so that the dielectric substrate can be laminated on the upper surface; and A radiation patch formed on the upper surface of the above dielectric substrate and having a rectangular structure, wherein two diagonal corners among the corners of the rectangle are removed in a mutually parallel manner to generate circular polarization; and A power supply unit that supplies power to the radiation patch by penetrating the grounding substrate and the dielectric substrate. Circularly polarized antenna for UHF band RFID reader
- In paragraph 1, The above power supply unit is characterized by supplying power to the radiation patch by vertically penetrating the grounding substrate and the dielectric substrate. Circularly polarized antenna for UHF band RFID reader
- In paragraph 1, One side of the grounding substrate further includes an extension portion protruding upward to support one side of the dielectric substrate. The above-mentioned power supply unit is characterized by supplying power to the radiation patch by horizontally penetrating the above-mentioned extension unit and the above-mentioned dielectric substrate. Circularly polarized antenna for UHF band RFID reader
- In paragraph 1, To supply power, one end of the power supply unit is electrically connected to a coaxial connector; and the coaxial connector is connected to a coaxial cable. Circularly polarized antenna for UHF band RFID reader
- In paragraph 1, Characterized by independently adjusting the area of the removed corners and adjusting the area of the grounding substrate to generate a resonant frequency in the UHF frequency band. Circularly polarized antenna for UHF band RFID reader
Description
Circularly polarized antenna for RFID reader in UHF band The present invention relates to an antenna for an RFID reader, and more specifically, to a circularly polarized antenna for a UHF band RFID reader that generates circular polarization with a resonant frequency in the UHF band. Generally, antennas for RFID readers are of the basic form as patch antennas, and structures for 90-degree phase shift feeding, such as hybrid power dividers, are used to generate circular polarization, which has caused problems with miniaturization. In addition, the patch antenna of Korean Registered Patent No. 10-0837102 (published June 11, 2008) had a complex structure because it uses a Wilkins divider to form multiple feed points to generate circular polarization, which presented problems for commercialization. FIG. 1 is an exemplary top view of a circularly polarized antenna for a UHF band RFID reader according to the present invention. FIG. 2 is a side view of a circularly polarized antenna for a UHF band RFID reader according to the present invention. Figure 3 is an example diagram illustrating the magnitude and phase of the current according to frequency to explain why the antenna generates circular polarization. FIG. 4 is an example of a differently designed top view of a circularly polarized antenna for a UHF band RFID reader according to the present invention. FIG. 5 is a differently designed side view of a circularly polarized antenna for a UHF band RFID reader according to the present invention. Figure 6 is an example diagram illustrating the characteristics of an antenna that vary according to size parameters. Figure 7 is another example diagram illustrating the characteristics of an antenna that vary according to size parameters. Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed herein are provided merely for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described herein. Embodiments according to the concept of the present invention may be subject to various modifications and may take various forms; therefore, embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes all modifications, equivalents, or substitutions that fall within the spirit and scope of the present invention. Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. FIG. 1 is a top view example of a circularly polarized antenna for a UHF band RFID reader according to the present invention, FIG. 2 is a side view example of a circularly polarized antenna for a UHF band RFID reader according to the present invention, FIG. 3 is an example of showing the magnitude and phase of the current according to frequency to explain why the antenna generates circular polarization, FIG. 4 is a top view example of a differently designed circularly polarized antenna for a UHF band RFID reader according to the present invention, FIG. 5 is a side view example of a differently designed circularly polarized antenna for a UHF band RFID reader according to the present invention, FIG. 6 is an example of explaining the characteristics of an antenna that change according to a size parameter, and FIG. 7 is another example of explaining the characteristics of an antenna that change according to a size parameter. A circularly polarized antenna for an RFID reader in the UHF band according to the present invention has a radiation patch (200) formed on the upper surface of a dielectric substrate (100) having a predetermined dielectric constant, which exchanges information with an external tag, and a grounding substrate (300) is formed only on the lower surface of the dielectric substrate (100), or an 'L'-shaped grounding substrate (300) is formed including an extension (310) having a grounding surface on the lower surface of the dielectric substrate (100) and one side surface, and a feed portion (410) is formed penetrating the grounding substrate (300) and the dielectric substrate (100) to supply power to the radiation patch (200) formed as described above. As illustrated in FIG. 1, as two diagonal corners of the radiation patch (200) are removed, the antenna generates circular polarization, and the frequency at which circular polarization occurs is determined by the existing area of the radiation patch (200). The size of the radiation patch (200) of a circularly polarized antenna can be calculated by the following formula, where W (10) is the formula It is calculated as, and L(20) is It is calculated as, and the length of the edge removed for circular polarization is the formula The edge a