TW201405941A - Dual-polarized antenna - Google Patents

Abstract

The present invention relates to a dual-polarized antenna , which includes a base; a chip disposed on the base surface, wherein the first side and a second side of the chip are electrically connected to a first radiation section with the first side and the second side being two opposite sides, the third and fourth sides of the chip are respectively electrically connected to a second radiation section, and the third side and the fourth side are opposite to the second side; an annular metal which is disposed on the base surface and is separately straddled over each of a section in the first radiating metal segment and a section in the second radiating metal segment. Known from the above-mentioned structure, the dual-polarized antenna of the present invention has the properties of the broadband operation and bidirectional radiation field, and the reading bandwidth range can cover the entire UHF frequency bands, with advantages of the preferable reading range, the long reading distance, the fabrication simplicity, the lower cost, etc., to solve the shortages of the prior art.

Description

Dual polarized antenna

The invention relates to an antenna, in particular to a dual-polarized antenna.

RFID is the abbreviation of "Radio Frequency Identification". Chinese can be called "Radio Frequency Identification". This is a non-contact automatic identification system that uses radio waves to transmit identification data. The non-contact automatic identification system includes: Tag, a reader (Reader) and a computer information system.
The RFID tag basically consists of an antenna that transmits electromagnetic signals and a silicon chip that can store data, and then is packaged in glass or plastic components. The RFID tag in the sensing range generates an induced current through the antenna and the electromagnetic wave, and after supplying the chip on the RFID tag, the electromagnetic wave is transmitted through the antenna to the reader. Different from the source of driving energy, RFID tags can be divided into active and passive types: passive RFID tags have no battery devices themselves, and the required current depends on receiving radio waves from the reader to generate induced current, so only After receiving the signal sent by the reader, the chip will passively respond to the reader; and the active RFID tag has a battery inside, which can actively transmit signals for reading by the reader, and the signal transmission range is also relatively More extensive than passive RFID tags.
Currently, RFID tags use 13.56MHz, 900MHz, 2.4 GHz, and 5.8 GHz. Therefore, the input impedance of RFID tag implanted chips varies with operating frequency bands. RFID tags with long read distances can be used in factory automation, sales of goods, and RFID tags with short read distances can be used in toll collection systems or vehicle identity recognition.
However, most of the RFID tag antennas currently on the market are designed for linear polarization, and most of them are mainly designed with narrow frequency, but cannot cover the UHF full frequency band, and have short reading distance and easy to produce dead angles. Therefore, the inventors believe that there is a need for improvement.

In order to solve the deficiencies described in the prior art, the inventors propose a dual-polarized antenna comprising:
a pedestal.
A wafer:
The first surface and the second side of the chip are electrically connected to a first radiant metal segment, and the first side and the second side are opposite sides, and the chip is The third side and the fourth side are respectively electrically connected to a second radiating metal section, and the third side and the fourth side are opposite sides.
a ring metal:
The annular metal is disposed on the surface of the base, and spans one of the first radiating metal segments and one of the second radiating metal segments.
According to the above configuration, the read range of the dual-polarized antenna of the present invention can cover the entire UHF frequency band, and has the characteristics of two-way radiation field type and wide-band operation, and has a better reading range and reading distance. The deficiencies described in the prior art are solved.

The construction, features and embodiments of the present invention are illustrated by the accompanying drawings, which will be further understood by the review.
Referring to the first figure, the present invention relates to a dual-polarized antenna (A) comprising:
A base (1).
Referring to the first figure, the pedestal (1) is preferably selected from an FR4 fiberglass substrate to reduce the manufacturing cost of the dual-polarized antenna (A), and the dual-polarized antenna (A) is The UHF band has better stability.
A wafer (2):
Referring to the first figure, the wafer (2) is disposed on the surface of the pedestal (1), and the first side and the second side of the wafer (2) are electrically connected to a first radiant metal segment (3), respectively. The first side and the second side are opposite sides, and the third side and the fourth side of the wafer (2) are electrically connected to a second radiating metal section (4), respectively, and the third side and the The fourth side is the opposite side.
The dual-polarized antenna (A) can control the resonant frequency by controlling the length of the first radiating metal segment (3) and the second radiating metal segment (4), wherein the first radiating metal segment (3) The length is preferably less than the length of the second radiant metal segment (4), which has enabled the dual polarized antenna (A) to have two resonant frequencies. Moreover, the first side and the third side of the wafer (2) preferably exhibit an angle of 90 degrees, and the direction of the free ends of the second segments (32) is perpendicular to the direction of the free ends of the fourth segments (42). The dual-polarized antenna (A) has a better reading range.
a ring metal (5):
Referring to the first figure, the annular metal (5) is disposed on the surface of the base (1), and spans one segment of each of the first radiating metal segments (3) and each of the second radiating metal segments (4). a section of the first radiating metal (3) divided into a first segment (31) and a second segment (32), and the first segment (31) is located in the annular metal ( 5) inside, and the second radiant metal segment (4) is divided into a third segment portion (41) and a fourth segment portion (42), and the third segment portion (41) is located at the annular metal (5) Inside.
The impedance characteristic of the dual-polarized antenna (A) can be adjusted by the annular metal (5), and when the length of the annular metal (5) is 34 (1±5%) mm, the width is 4 (1± 5%) mm has a better effect. And the first segment (31) is preferably provided with a plurality of first bending portions (311), and the third segment portion (41) is provided with a plurality of second bending portions (411), thereby lifting the bipolar portion The inductance value and reading effect of the antenna (A). In order to reduce the area of the dual-polarized antenna (A), the second segment portion (32) is preferably provided with a plurality of third bending portions (321), and the fourth segment portion (42) is preferably provided with plural numbers. Four bends (421).
The advantages of the dual-polarized antenna (A) are illustrated by using the schematic diagrams of the respective measurement results, and the length of the first radiating metal segment (3) is 102.5 (1±5%) mm, and the second radiating metal segment (4) The length is 107.5 (1±5%) mm for measurement:
Referring to the second figure, the second figure measures the return loss of the dual-polarized antenna (A). The vertical axis represents the return loss (dB) and the horizontal axis represents the operating frequency (MHz). As can be seen from the figure, the dual-polarized antenna (A) has a bandwidth ranging from 857 to 1000 MHz with a return loss value of 3 dB or more, which covers the bandwidth requirements of the UHF global frequency band.
Referring to the third figure, the third figure measures the result of the resistance of the dual-polarized antenna (A). In the figure, the vertical axis represents ohms (Ω), and the horizontal axis represents the operating frequency (MHz); As can be seen from the figure, the dual-polarized antenna (A) has a characteristic of a real imaginary impedance due to the impedance of the wafer (2), and the dual-polarized antenna (A) utilizes the ring for better impedance conjugate matching. The metal (5) adjusts the input impedance, and excites the high frequency resonant mode by using each of the first radiating metal segments (3), and excites the low frequency resonant mode by using each of the second radiating metal segments (4), and adjusts the first The length of the radiant metal segment (3) and the second radiant metal segment (4) will combine the dual resonant modes of the dual polarized antenna (A) to cover the UHF global frequency band.
Referring to the fourth figure, the fourth figure is a measurement result of the reactance experiment of the dual-polarized antenna (A). The vertical axis represents ohms (Ω), and the horizontal axis represents the operating frequency (MHz); As can be seen from the fourth figure, the dual-polarized antenna (A) utilizes the characteristics of the real imaginary impedance of the impedance of the wafer (2), and the dual-polarized antenna (A) utilizes the ring for better impedance conjugate matching. The metal (5) adjusts the input impedance, and excites the high frequency resonant mode by using each of the first radiating metal segments (3), and excites the low frequency resonant mode by using each of the second radiating metal segments (4), and adjusts the first The length of a radiating metal segment (3) and the second radiating metal segment (4) will combine the dual resonant modes of the dual polarized antenna (A) to cover the UHF global frequency band.
Referring to the fifth figure, the fifth figure is a schematic diagram of the result of measuring the read range of the dual-polarized antenna (A); as can be seen from the figure, the dual-polarized antenna (A) is typical in XY Plane. The two-way radiation read range type, the reading distance is up to 6.2 meters.
It can be seen from the above that the dual-polarized antenna (A) of the present invention has the characteristics of wide-band operation and bidirectional radiation field type, and the read bandwidth ranges from 857 to 100 MHz, and can cover the entire UHF frequency band, and is better. The reading range and the reading distance are up to 6.2 m, the production is simple, the cost is low, and the like, and the disadvantages described in the prior art are solved.
In summary, the present invention is indeed in line with industrial utilization, and is not found in publications or publicly used before application, nor is it known to the public, and has non-obvious knowledge, conforms to patentable requirements, and patents are filed according to law. .
However, the above description is a preferred embodiment of the invention in the industry, and all the equivalent changes made according to the scope of the patent application of the present invention belong to the scope of the claim.

(A). . . Dual polarized antenna

(1). . . Pedestal

(2). . . Wafer

(3). . . First radiant metal segment

(31). . . First section

(311). . . First bend

(32). . . Second paragraph

(321). . . Third bend

(4). . . Second radiant metal segment

(41). . . Third paragraph

(411). . . Second bend

(42). . . Fourth paragraph

(421). . . Fourth bend

(5). . . Ring metal

The first picture is a schematic diagram of the dual-polarized antenna. The second picture is the result of measuring the return loss of the dual-polarized antenna. The third picture is the result of measuring the resistance of the dual-polarized antenna. The fourth picture is the measurement of the dual-polarized antenna. The result of the reactance experiment is shown in the fifth figure. The result of measuring the reading range of the dual-polarized antenna

(A). . . Dual polarized antenna

(1). . . Pedestal

(2). . . Wafer

(3). . . First radiant metal segment

(31). . . First section

(311). . . First bend

(32). . . Second paragraph

(321). . . Third bend

(4). . . Second radiant metal segment

(41). . . Third paragraph

(411). . . Second bend

(42). . . Fourth paragraph

(421). . . Fourth bend

(5). . . Ring metal

Claims (7)

A dual polarized antenna comprising:
a pedestal
a chip is disposed on the surface of the pedestal, the first side and the second side of the chip are electrically connected to a first radiant metal segment, and the first side and the second side are opposite sides, the chip The third side and the fourth side are respectively electrically connected to a second radiating metal segment, and the third side and the fourth side are opposite sides;
An annular metal is disposed on the surface of the base and spans one of the first radiating metal segments and one of the second radiating metal segments. The dual-polarized antenna according to claim 1, wherein the annular metal divides the first radiating metal segment into a first segment and a second segment, the ring metal is the second radiating metal The segment is divided into a third segment and a fourth segment, and the first segment and the third segment are respectively located in the annular metal, and the first segment is provided with a plurality of first bending portions, the first portion The third section is provided with a plurality of second bending portions. The dual-polarized antenna according to claim 2, wherein the second segment is provided with a plurality of third bent portions, and the fourth segment is provided with a plurality of fourth bent portions. The dual-polarized antenna according to claim 3, wherein the direction of the free ends of the second segments is perpendicular to the direction of the free ends of the fourth segments. The dual-polarized antenna of claim 1, wherein the length of the first radiating metal segment is less than the length of the second radiating metal segment. The dual-polarized antenna according to claim 5, wherein the length of the first radiating metal segment is 102.5 (1±5%) mm, and the length of the second radiating metal segment is 107.5 (1±5%). Mm. The dual-polarized antenna of claim 1, wherein the base is an FR4 fiberglass substrate.