Combined planar oscillator near-field antenna

Abstract

A combined planar radiator near-field antenna comprises a radiator PCB, a microstrip circuit feed PCB, and vertical metal feed posts connecting the radiator PCB and the microstrip circuit feed PCB. A combined planar radiator is provided on the upper surface of the radiator PCB, the combined planar radiator comprising a plurality of metal copper foils, each provided with a soldering via. The microstrip circuit feed PCB is provided with a microstrip distribution circuit, the microstrip distribution circuit being provided with a microstrip feed port and a plurality of metal feed post feed points. Compared with the prior art, the present invention has the beneficial effects of: using the combined planar radiator as the basic radiator facilitates achieving a large and stable near-field radiation area, and each metal copper foil is connected using an independent metal feed post feed point. The microstrip distribution circuit is used to sequentially configure corresponding feeding phases and equal-amplitude feeding levels to achieve circularly polarized operating characteristics.

Description

Technical field

[0001] The present invention relates to the technical field of antennas, and in particular to a combined planar oscillator near-field antenna. [Background Technology]

[0002] The widespread application of radio frequency identification (RFID) product technology has directly promoted the rapid development of near-field antenna technology. Unlike conventional far-field antennas, the application of near-field antennas in the ultra-high frequency band has relatively special technical requirements. Its characteristics can be roughly summarized as follows: (1) The physical distance between the electronic tag to be read and written (i.e., the item to be identified) and the read-write antenna is very close, requiring the near-field field strength distribution excited by the antenna to be stable and uniform; (2) The far-field gain of the antenna should not be too large, otherwise it will misread nearby items and cause interference to nearby shelves; (3) Electronic tags are usually placed in any direction, and the read-write antenna usually needs to adopt circular polarization working mode to obtain a relatively stable read-write signal and avoid missed reading as much as possible; (4) The electronic tags to be read and written are densely placed in a relatively large display area, which will exceed the coverage capacity of a single-element antenna. It is necessary to use multiple elements and form an antenna array in an appropriate manner to effectively expand the range of the read-write area; (5) The installation space of the read-write antenna on various shelves of various items is extremely limited, and a compact and efficient antenna structure is required to reduce the overall size of the antenna.

[0003] In response to the above application requirements, the design of near-field antennas faces technical difficulties due to the mutual constraints of multiple factors. For example, limited space and size require the realization of multi-element arrays, stable near-field performance and suppression of far-field gain, realization of circular polarization and control of feeding circuit complexity, etc. Choosing a more reasonable technical approach and balancing the overall solution of multiple requirements are the key to this type of near-field antenna design technology.

[0004] In view of this, it is necessary to provide a combined planar dipole near-field antenna to overcome the shortcomings of the existing technology. [Summary of the invention]

[0005] The purpose of the present invention is to provide a combined planar dipole near-field antenna, which uses a combined planar radiating dipole as a basic radiator to easily achieve a large and stable near-field radiation area. In addition, each metal copper foil is connected to a feeding point using an independent metal feeding post, and a microstrip distribution circuit is used to sequentially configure the corresponding feeding phase and equal-amplitude feeding level to achieve circular polarization working characteristics. The overall structure is compact and practical, and well meets the requirements of near-field antenna design and application.

[0006] In order to achieve the above-mentioned object, the present invention provides a combined planar dipole near-field antenna, comprising a radiator PCB board, a microstrip circuit feed PCB board, and a vertical feed metal post connecting the radiator PCB board and the microstrip circuit feed PCB board;

[0007] A combined planar radiating oscillator is provided on the upper surface of the radiator PCB board, and the combined planar radiating oscillator includes several metal copper foils, each of which is provided with a soldering via; a microstrip distribution circuit is provided on the microstrip circuit feeding PCB board, and the microstrip distribution circuit is provided with a microstrip feeding port and several metal feeding column feeding points, each metal feeding column feeding point coincides with the center of the vertical projection of a corresponding soldering via, one end of the vertical feeding metal column is soldered to the metal feeding column feeding point and the other end passes through the soldering via corresponding to the metal feeding column feeding point on the back of the radiator PCB board and is electrically connected.

[0008] In a preferred embodiment, the microstrip distribution circuit is composed of a microstrip power division circuit, a microstrip phase shift circuit, and an impedance matching circuit.

[0009] In a preferred embodiment, the plurality of metal copper foils are distributed in a polar array.

[0010] In a preferred embodiment, the metal copper foil is rectangular.

[0011] In a preferred embodiment, two microstrip distribution circuits connected in parallel are provided on the microstrip circuit feed PCB board, and two groups of combined planar radiating oscillators are provided on the upper surface of the radiator PCB board. One end of the vertical feeding metal column is welded to the feeding point of the metal feeding column and the other end is electrically connected through the welding via corresponding to the feeding point of the metal feeding column on the back of the radiator PCB board.

[0012] Compared with the prior art, the combined planar oscillator near-field antenna provided by the present invention has the following beneficial effects: a combined planar radiating oscillator is used as the basic radiator, which makes it easy to achieve a large and stable near-field radiation area, and each metal copper foil is connected to the feeding point using an independent metal feeding column, and a microstrip distribution circuit is used to sequentially configure the corresponding feeding phase and equal-amplitude feeding level to achieve circular polarization working characteristics; the overall structure is compact and practical, and well adapted to the requirements of near-field antenna design and application.

Brief Description of the Drawings

[0013] Figure 1 This is a three-dimensional diagram of the combined planar oscillator near-field antenna provided by the present invention.

[0014] Figure 2 for Figure 1 The exploded diagram of the combined planar oscillator near-field antenna is shown.

[0015] Figure 3 for Figure 1 Top view of the microstrip circuit feeding PCB board shown.

[0016] Figure 4An exploded view of a combined planar dipole near-field antenna provided in a preferred embodiment of the present invention. [Specific implementation method]

[0017] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0018] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0020] See also Figures 1 to 3 The present invention provides a combined planar oscillator near-field antenna 100.

[0021] In an embodiment of the present invention, the combined planar dipole near-field antenna 100 includes a radiator PCB board 10 , a microstrip circuit feed PCB board 20 , and a vertical feed metal post 30 connecting the radiator PCB board 10 and the microstrip circuit feed PCB board 20 .

[0022] Specifically, a combined planar radiating oscillator 11 is provided on the upper surface of the radiator PCB board 10, and the combined planar radiating oscillator 11 includes a plurality of metal copper foils 111, and the plurality of metal copper foils 111 are distributed in a polar array, and the metal copper foils 111 are rectangular, and each metal copper foil 111 is provided with a welding via 1111; the microstrip circuit feeding PCB board 20 is provided with a microstrip distribution circuit 21, and the microstrip distribution circuit 21 is provided with a microstrip feeding port 211 and a plurality of metal feeding column feeding points 212, each metal feeding column feeding point 212 coincides with the center of the corresponding welding via 1111 in the vertical projection, and one end of the vertical feeding metal column 30 is welded to the metal feeding column feeding point 212 and the other end passes through the radiator PCB board 10 and is electrically connected to the welding via 1111 corresponding to the metal feeding column feeding point 212.

[0023] It is understood that the combined planar radiating elements 11 on the radiator PCB 10 can form a relatively single and stable near-field radiation pattern in the close-range radiation area on its upper surface, which is beneficial to the performance of the near-field antenna. The microstrip distribution circuit 21 is composed of a traditional microstrip power splitter circuit, a microstrip phase shifter circuit, and an impedance matching circuit. The ground plane of the microstrip PCB also serves as the antenna reflector. Due to the closely arranged structural characteristics of the combined planar radiating elements 11, there is a large capacitive coupling between the four independent combined planar radiating elements 11, and a strong capacitive reactance is also generated between the antenna reflectors. The design and working principle of the impedance matching circuit is to eliminate capacitive reactance and maintain the impedance matching to 50Ω within the working bandwidth; the design principle of the microstrip phase shift circuit is to sequentially configure the feeding phase of the feeding column with a phase difference of 90 degrees, for example: feeding point 1 is 0 degrees, feeding point 2 is 90 degrees, feeding point 3 is 180 degrees, and feeding point 4 is 270 degrees, in order to meet the phase conditions for circular polarization feeding; the design principle of the microstrip power splitter circuit is to feed the four metal feeding columns with equal amplitude, that is, a conventional equal amplitude 1-to-4 power splitter circuit can be used to meet the amplitude requirements of circular polarization feeding. The design and application technology of microstrip circuits is a very mature public technology. Figure 3 The copper foil trace pattern of the microstrip circuit shown is only a practical application demonstration for reference. Its specific dimensions will be affected by multiple factors such as the actual PCB board parameters, antenna structure parameters, and the antenna's operating frequency. There is no unique correspondence with the near-field antenna technology disclosed in this patent. Technicians in the field of RF antenna technology can accurately understand and design applications based on the above design principles.

[0024] The combined planar oscillator near-field antenna 100 uses a combined planar radiating oscillator 11 as a basic radiator, which makes it easy to achieve a large and stable near-field radiation area. In addition, each metal copper foil 111 is connected by an independent metal feeding post and feeding point 212, and the corresponding feeding phase and equal amplitude feeding level are sequentially configured using a microstrip distribution circuit 21 to achieve circular polarization operating characteristics. The overall structure is compact and practical, and well meets the requirements of near-field antenna design and application.

[0025] See also Figure 4 In a preferred embodiment, by utilizing the technical solution of the above-mentioned combined planar oscillator near-field antenna 100, in actual applications, the smooth expansion of the near-field antenna working area can be flexibly achieved through array combination, thereby further illustrating the feasibility and practicality of the patented technology.

[0026] Specifically, two microstrip distribution circuits 21 connected in parallel are provided on the microstrip circuit feeding PCB board 20, and two groups of combined planar radiating oscillators 11 are provided on the lower surface of the radiator PCB board 10. One end of the vertical feeding metal column 30 is welded to the metal feeding column feeding point 212 and the other end passes through the radiator PCB board 10 and is electrically connected to the welding via 1111 corresponding to the metal feeding column feeding point 212.

[0027] It must be noted that the added feed post ports, created by duplicating and translating them, should maintain the same phase and amplitude signal levels as the original feed post ports to maintain the circular polarization and near-field performance of the expanded antenna. By duplicating and translating the aforementioned microstrip distribution circuit 21, while also correspondingly expanding the size and area of ​​the radiator PCB 10, the microstrip circuit feed PCB 20, and the number of metal feed post feed points 212, a larger rectangular antenna operating area can be conveniently achieved, enabling reading and writing electronic tags over a wider area. The combined planar dipole near-field antenna 100 exhibits an overall flat structure.

[0028] It is understood that a similar method can be used to rotate and replicate the basic planar pattern to form a combined planar radiating element 11 (including but not limited to 3, 4, 6, 8, etc.) of metal copper foils 111. Using a similar method, the microstrip circuit feed PCB board 20 can also be provided with 4, 5, 6, 8, etc., microstrip distribution circuits 21 connected in parallel. The above technical solution is also applicable to far-field antennas. Those skilled in the art will appreciate that various variations and improvements can be made without departing from the scope of the present invention, and all of these fall within the scope of protection of this technical solution.

[0029] Compared with the prior art, the combined planar oscillator near-field antenna provided by the present invention has the following beneficial effects: a combined planar radiating oscillator is used as the basic radiator, which makes it easy to achieve a large and stable near-field radiation area, and each metal copper foil is connected to the feeding point using an independent metal feeding column, and a microstrip distribution circuit is used to sequentially configure the corresponding feeding phase and equal-amplitude feeding level to achieve circular polarization working characteristics; the overall structure is compact and practical, and well adapted to the requirements of near-field antenna design and application.

[0030] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The above embodiments merely represent several implementation methods of the present invention. The descriptions thereof are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that the scope of protection of the present invention patent shall be based on the appended claims.

Claims

1. A combined planar dipole near-field antenna, characterized in that: It includes a radiator PCB board, a microstrip circuit feeding PCB board and a vertical feeding metal column connecting the radiator PCB board and the microstrip circuit feeding PCB board; The upper surface of the radiator PCB is provided with a combined planar radiating oscillator, which includes a plurality of metal copper foils, each of which is provided with a soldering via. The microstrip circuit feed PCB is provided with a microstrip distribution circuit, which is provided with a microstrip feeding port and a plurality of metal feeding column feeding points. Each metal feeding column feeding point coincides with the center of a corresponding soldering via in the vertical projection. One end of the vertical feeding metal column is soldered to the metal feeding column feeding point, and the other end passes through the soldering via corresponding to the metal feeding column feeding point on the rear side of the radiator PCB and is electrically connected. The microstrip circuit feed PCB is provided with two microstrip distribution circuits connected in parallel with each other. The upper surface of the radiator PCB is provided with two groups of combined planar radiating oscillators. One end of the vertical feeding metal column is welded to the feeding point of the metal feeding column, and the other end passes through the welding via corresponding to the feeding point of the metal feeding column on the back of the radiator PCB and is electrically connected. The combined planar radiating element on the radiator PCB board can form a single stable near-field radiation field pattern in the close-range radiation area on its upper surface, which is beneficial to the performance of the near-field antenna. The microstrip distribution circuit is composed of a traditional microstrip power division circuit, a microstrip phase shift circuit, and an impedance matching circuit, and the ground plane of the microstrip PCB also serves as an antenna reflector. Due to the closely arranged structural characteristics of the combined planar radiating element, there is capacitive coupling between the four independent combined planar radiating elements, and capacitive reactance is also included between the antenna reflectors. The design and working principle of the impedance matching circuit is to eliminate the capacitive reactance and keep the impedance matching within the working bandwidth at 50Ω; the design principle of the microstrip phase shift circuit is to sequentially configure the feeding phase of the feeding column with a phase difference of 90 degrees.

2. The combined planar oscillator near-field antenna according to claim 1, wherein: A plurality of metal copper foils are distributed in a polar array.

3. The combined planar dipole near-field antenna according to claim 2, wherein: The metal copper foil is rectangular.

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