WO2016197910A1

WO2016197910A1 - Rfid tag antenna with isolation groove

Info

Publication number: WO2016197910A1
Application number: PCT/CN2016/085113
Authority: WO
Inventors: 张秀丽
Original assignee: 张秀丽
Priority date: 2015-06-11
Filing date: 2016-06-07
Publication date: 2016-12-15
Also published as: CN107534204B; CN104953236B; CN104953236A; CN107534204A

Abstract

Disclosed is an RFID tag antenna with an isolation groove, comprising a first antenna and a second antenna with an adjustable distance therebetween. The RFID tag antenna has a long reading distance that can reach 11 m to 13 m according to tests, and is extendable, that is, has an adjustable length. The RFID tag antenna is applicable to a suite with a substantially fixed width and an undetermined length, features good antenna performance, small standing-wave ratio, low return loss, high gain, and omnidirectivity, and therefore has great practical value.

Description

RFID tag antenna with isolation slot

Technical field

The present invention relates to an RFID tag antenna provided with an isolation slot.

Background technique

Currently, RFID (Radio Frequency Identification) technology, also known as electronic tag, radio frequency identification, is a type of radio signal that can identify a specific target and read and write related data without identifying the system and establishing a mechanical or specific target. Optical contact communication technology. Commonly used passive RFIDs have low frequency (125k ~ 134.2K), high frequency (13.56Mhz), ultra high frequency (860-960MHz). As an important part of the RFID system, the RFID tag antenna will greatly affect the efficiency and quality of the entire RFID system. The main factors affecting the performance of RFID antennas include antenna size, operating frequency band, impedance and gain. Commonly used RFID antennas often use a bent line dipole form, which is convenient for reducing antenna size and antenna processing. This type of antenna pattern is perpendicular to the antenna surface, so it is attached to the vertical outer surface of the target object when used; when the length of the object changes, the antenna is required to change, and the gain also changes, so it needs to be designed. An antenna that can change according to the length, in addition, its antenna performance also needs to meet the requirements.

Summary of the invention

It is an object of the present invention to overcome the above-discussed shortcomings and to provide an RFID tag antenna having an isolation slot.

To achieve the above objective, a specific solution of the present invention is as follows: An RFID tag antenna provided with an isolation slot includes a first antenna and a second antenna, and a distance between the first antenna and the second antenna is telescopically adjustable.

The first antenna includes an elongated first body, one end of the first body is provided with a first gain rod, and the free end of the first gain rod is provided with an arc-shaped first gain antenna, and two a coupling groove, the two coupling groove openings are opposite to the other end of the first body, the two coupling grooves are disposed in parallel in the first body, and the upper and lower sides of each coupling groove are provided with serrated zigzag grooves; The second antenna includes a second body, the first body has a length greater than the second body, and the second body has a second gain rod at one end thereof, and the free end of the second gain rod is provided with an arc shape. The second gain antenna further includes two coupling strips disposed on the other end of the second body and engaging with the coupling grooves. The two coupling strips are disposed in parallel, and the upper and lower sides of each of the coupling strips are provided with a sawtooth slot. a matching serrated serration protrusion, the serration protrusion being located in the serration groove when mated;

The utility model further includes a T-shaped adjusting rod, wherein the second body is provided with an opening corresponding to the opening of the first body, and the horizontal section of the T-shaped adjusting rod is located in the adjusting recess;

The distance between the free end of the coupling strip and the inner side of the coupling groove is L, and the horizontal distance between the free end of the horizontal section of the T-shaped adjustment rod and the inner side of the adjustment recess is M, and the L=M*3.75.

Wherein, one end of the first body is an arc surface, and the arc is the same as the arc of the first gain antenna.

Wherein, one end of the second body is a curved surface, and the arc is the same as the arc of the second gain antenna.

The first gain antenna and the second gain antenna have the same arc, both of which are 60°-80°.

Wherein, a side of the first gain antenna is further provided with a third gain rod, and a free end of the third gain rod is provided with a third gain antenna.

The arc of the third gain rod is the same as the arc of the first gain rod.

Wherein the height of the first body is less than 10 cm.

Wherein the first antenna is provided with an elongated isolation groove,

The second antenna and the first antenna are provided with a frequency increase gap.

The invention has the following advantages: 1. The reading distance is long, and the reading distance can be 11-13 m after being tested. The reading distance of ordinary RFID tag antennas is less than 10m. 2, stretchable; that is, the length is adjustable, it can be used for a package with a certain width, but the length is not fixed, has great practical value. 3. Various antennas have good performance, small standing wave ratio, low return loss, high gain and omnidirectionality. It has higher performance when used at a frequency of ultra high frequency (860-960 MHz), especially around 925 MHz.

DRAWINGS

Figure 1 is a schematic view of the present invention;

Figure 2 is a schematic view of the elongated state of the present invention;

Figure 3 is a schematic view of a first antenna of the present invention;

Figure 4 is a schematic view of a second antenna of the present invention;

Figure 5 is a schematic illustration of an RFID tag made using the present invention;

Figure 6 is a graph of impedance test data of the present invention;

Figure 7 is a graph of return loss test data of the present invention;

Figure 8 is a diagram showing the directional test data of the present invention;

The reference numerals in Figures 1 to 8 illustrate:

1-first antenna; 11-coupling slot; 12-zig slot; 13-first gain lever; 14-first gain antenna; 15-third gain lever; 16-third gain antenna; 17-isolation slot; - an increase in frequency gap;

2-second antenna; 21-coupling strip; 22-toothed protrusion; 23-second gain rod; 24-second second gain antenna; 25-adjusting notch;

3-T-shaped adjustment lever;

4-medium plate;

5-label chip;

6-substrate.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1 to FIG. 8 , an RFID tag antenna provided with an isolation slot according to the embodiment includes a first antenna 1 and a second antenna 2, and the first antenna 1 and the second antenna 2 The distance between the two is adjustable. The RFID tag manufactured by the same comprises a substrate 6 and an RFID tag antenna provided on the substrate 6 with an isolation slot. The second antenna 2 is provided with a dielectric plate 4, and the dielectric plate 4 is provided with a tag chip 5, The tag chip 5 is electrically connected to the antenna.

An RFID tag antenna provided with an isolation slot according to the embodiment, the first antenna 1 includes an elongated first body, and one end of the first body is provided with a first gain lever 13, the first gain The free end of the rod 13 is provided with an arc-shaped first gain antenna 14 and further includes two coupling slots 11 which are open toward the other end of the first body, and the two coupling slots 11 are arranged in parallel In the first body, the upper and lower sides of each coupling groove 11 are provided with serrations The second antenna 2 includes a second body, the first body has a length greater than the second body, and one end of the second body is provided with a second gain rod 23, and the second gain rod The second end of the second body is provided with two arc-shaped second gain antennas 24, and further includes two coupling strips 21 disposed at the other end of the second body, and the two coupling strips 21 are arranged in parallel. The upper and lower sides of each of the coupling strips 21 are provided with serrated serrations 22 that cooperate with the serrations 12 . When mated, the serrations 22 are located in the serrations 12; The RFID tag antenna of the isolation slot further includes a T-shaped adjustment rod 3, and the second body is provided with an adjustment recess 25 facing the first body, and the horizontal section of the T-shaped adjustment rod 3 is located at the adjustment recess 25 An RFID tag antenna provided with an isolation slot according to the embodiment, wherein the free end of the coupling strip 21 and the inner side of the coupling slot 11 are L, and the free end of the horizontal section of the T-shaped adjustment rod 3 is provided. The horizontal distance from the inner and inner sides of the adjustment recess 25 is M, and the L = M * 3.75.

The program achieves a long reading distance by the above features, and the reading distance can be 11-13 m after testing. The reading distance of ordinary RFID tag antennas is less than 10m. In addition, it can be stretched; that is, the length is adjustable, and it can be used for a package having a substantially constant width, but the length is not fixed, and has great use value, and is attached on different packages, and in addition, theoretically, it can grow indefinitely. Finally, its antenna performance is good, the standing wave ratio is small, the return loss is low, the gain is high, and it is omnidirectional. It has higher performance when used at frequencies around 925MHz. In the embodiment, the RFID tag antenna provided with the isolation slot has an arcuate surface at one end and the arc of the first gain antenna 14 is the same. With such a setting, the gain performance is further improved, the return loss is reduced, the omnidirectionality of the radiation is increased, and the optimization result is better. In the embodiment, the RFID tag antenna provided with the isolation slot has an arc-shaped surface at one end and the arc of the second gain antenna 24 is the same. The same arc can reduce the formation of standing waves between the two antennas, reduce wave interference, and reduce the standing wave ratio. In the embodiment of the present invention, an RFID tag antenna provided with an isolation slot, the first gain antenna 14 and the second gain antenna 24 have the same arc, both of which are 60°-80°. Through the simulation and actual experiments, the performance of the radian antenna is the best.

An RFID tag antenna provided with an isolation slot is provided with a third gain lever 15 on one side of the first gain antenna 14 and a third end on the free end of the third gain lever 15 The gain antenna 16; the RFID tag antenna provided with the isolation slot in the embodiment, the arc of the third gain lever 15 is the same as the arc of the first gain bar 13; similarly, the setting is further improved. Gain performance, and reduce return loss, increase radiation omnidirectionality, optimization results are better.

In the embodiment, an RFID tag antenna provided with an isolation slot has a height of less than 10 cm. An RFID tag antenna provided with an isolation slot is provided in the embodiment. The first antenna 1 is provided with an elongated isolation slot 17 , and the isolation slot 17 is located between the two coupling slots 11 . An RFID tag antenna provided with an isolation slot according to the embodiment, the second antenna 2 is located at two corners of one side of the first antenna 1 and at two corners of a side of the first antenna 1 adjacent to the second antenna 2 There is a frequency increase gap 18. The up-sampling gap 18 increases the isolation and reduces the formation of standing waves, making the standing wave ratio close to one. The antenna of this scheme also has a good performance in terms of omnidirectionality. As shown in Fig. 8, it has excellent performance in omnidirectionality and has a 360 degree dead angle equidistance omnidirectionality. As shown in Figure 7, the return loss performance is outstanding, especially at 925MHz, the minimum return loss is -65dB, and the return loss is kept below -10dB in the entire high frequency band, and the average level is higher than other similar antenna levels.

According to the test, the effective distance is 11-13m under different tensile lengths. The test results are as follows:

In addition, the input impedance of the antenna test is shown in Fig. 6. The measured impedance is 11+144j ohms at 925MHz, which is conjugate matched with the impedance 11+143j of the chip Monza4Dura. The label achieves optimal results at 925MHz.

The above is only a preferred embodiment of the present invention, and equivalent changes or modifications made to the structures, features, and principles of the present invention are included in the scope of protection of the present invention.

Claims

An RFID tag antenna provided with an isolation slot, characterized in that: a first antenna (1) and a second antenna (2) are included, and a distance between the first antenna (1) and the second antenna (2) is Telescopic adjustment

The first antenna (1) is provided with an elongated isolation groove (17).
An RFID tag antenna provided with an isolation slot according to claim 1, wherein the first antenna (1) comprises an elongated first body, and one end of the first body is provided with a first gain lever (13) The free end of the first gain lever (13) is provided with an arc-shaped first gain antenna (14), and further includes two coupling slots (11), and the two coupling slots (11) are open The two coupling grooves (11) are disposed in parallel with each other in the first body, and the upper and lower sides of each of the coupling grooves (11) are provided with serrated zigzag grooves (12); The second antenna (2) includes a second body, the first body has a length greater than the second body, and one end of the second body is provided with a second gain rod (23), and the second gain rod (23) The free end is provided with a curved second gain antenna (24), and further comprises two coupling strips (21) disposed at the other end of the second body and engaging with the coupling grooves (11), the two coupling strips ( 21) Parallelly disposed, the upper and lower sides of each of the coupling strips (21) are provided with serrated serrations (22) that cooperate with the serrations (12). When mated, the serrations (22) ) located in the sawtooth groove (12);

Also included is a T-shaped adjustment rod (3) having an opening (25) opening toward the first body, the horizontal section of the T-shaped adjustment rod (3) being located at the adjustment recess (25) )Inside;

The distance between the free end of the coupling strip (21) and the inner side of the coupling groove (11) is L, and the horizontal distance between the free end of the horizontal section of the T-shaped adjustment rod (3) and the inner side of the adjustment recess (25) is set. For M, the L = M * 3.75.
The RFID tag antenna provided with the isolation slot according to claim 2, wherein one end of the first body is a curved surface and the arc is the same as the arc of the first gain antenna (14).
The RFID tag antenna provided with the isolation slot according to claim 2, wherein one end of the second body is a curved surface and the arc is the same as the arc of the second gain antenna (24).
The RFID tag antenna provided with the isolation slot according to claim 2, wherein the first gain antenna (14) and the second gain antenna (24) have the same curvature, both of which are 60°-80°. .
The RFID tag antenna provided with the isolation slot according to claim 2, wherein one side of the first gain antenna (14) is further provided with a third gain lever (15), the third gain The free end of the rod (15) is provided with a third gain antenna (16).
The RFID tag antenna provided with the isolation slot according to claim 6, wherein the arc of the third gain lever (15) is the same as the arc of the first gain lever (13).
The RFID tag antenna provided with the isolation slot according to claim 2, wherein the height of the first body is less than 10 cm.