KR100932558B1 - Radio wave identification tag and radio wave identification tag antenna - Google Patents

Abstract

The radio frequency identification tag includes an antenna and a chip, the antenna having a polyhedral shape stacked on a first dielectric having a polyhedron shape, a first microstrip line and a second microstrip line formed at a portion of the first dielectric, and a first dielectric. And a third microstrip line formed in the region of the second dielectric and a portion of the second dielectric. Through this, the radio frequency identification tag can efficiently receive electromagnetic waves to maximize the recognition distance.

RFID, radio wave identification, antenna, lamination

Description

Radio identification tag and radio identification tag antenna {RADIO FREQUENCY IDENTIFICATION TAG AND RADIO FREQUENCY IDENTIFICATION TAG ANTENNA}

The present invention relates to a radio wave identification tag and a radio wave identification tag antenna. In particular, the present invention relates to a radio wave identification tag and a radio wave identification tag antenna using a laminated structure.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development (Task Management No .: 2006-S-023-02, Task name: RFID system advancement technology development).

Radio Frequency IDentification System (hereinafter referred to as 'RFID System') is used in various applications such as logistics, traffic, security or safety. In general, an RFID system includes a radio frequency identification tag (hereinafter referred to as an 'RFID tag') and a radio frequency identification reader (hereinafter referred to as an 'RFID reader').

When the object to which the RFID tag is attached is located in the recognition region of the RFID reader, the RFID reader transmits an interrogating signal that modulates continuous electromagnetic waves having a specific frequency to the RFID tag. Thereafter, the RFID tag sends back the modulated electromagnetic wave to the RFID reader by performing back-scattering modulation on the electromagnetic wave transmitted from the RFID reader in order to deliver information stored in the internal memory to the RFID reader. In this case, the backscattering modulation is a method of transmitting the information stored in the RFID tag by modulating the magnitude or phase of the scattered electromagnetic wave when the RFID tag scatters the electromagnetic tag and sends it back to the reader.

The passive RFID tag rectifies the electromagnetic wave transmitted from the RFID reader and uses it as an operating power source. In order for the passive RFID tag to operate normally, the strength of the signal received by the RFID tag must be greater than or equal to a certain threshold.

At this time, the signal strength becomes weak when the distance between the RFID reader and the RFID tag increases, so that the RFID reader can recognize the RFID tag (hereinafter referred to as 'recognition distance') in the RFID system. The transmission power must be large. However, since the transmitting power of the RFID reader is regulated according to the local regulations of each country, it cannot be enlarged unconditionally. Therefore, in order to maximize the recognition distance with the limited transmitting power, the RFID tag must efficiently receive the electromagnetic waves transmitted from the RFID reader.

The technical problem to be achieved by the present invention is to provide an RFID tag that can maximize the recognition distance by efficiently receiving the electromagnetic wave transmitted from the RFID reader.

A radio wave identification tag according to an aspect of the present invention is a radio wave identification tag including an antenna for receiving a question signal corresponding to a radio frequency signal and a chip for generating a response signal corresponding to the question signal, wherein the antenna of the radio wave identification tag has a polyhedron shape. And a first dielectric, a first microstrip line, a second microstrip line, a polyhedral second dielectric and a third microstrip line. The first dielectric includes a first face corresponding to the ground plane and a second face not in contact with the first face. The first microstrip line is formed in a region of a portion of the second face and has two ends. The second microstrip line is formed in an area of a portion of the second face and has two ends. The second dielectric includes a third face that contacts a region of a portion of the second face and a fourth face that does not contact the third face, and is laminated to the first dielectric. The third microstrip line is formed on the fourth side and has two ends.

The antenna further includes a first feed terminal connected with one of the two ends of the first microstrip line and a second feed terminal connected with one of the two ends of the second microstrip line, and the chip has a second surface. It is formed in the region of the portion of the contact with the third surface, and is electrically connected to the first microstrip line through the first feed terminal, and is electrically connected to the second microstrip line through the second feed terminal.

Each of the impedance of the antenna and the impedance of the chip includes a resistance component and a reactance component, the values of the resistance component of the antenna impedance and the resistance component of the chip impedance have the same magnitude and sign, and the reactance of the impedance of the antenna The value of the component and the reactance component of the chip's impedance have the same magnitude and the opposite sign.

In addition, the impedance of the antenna corresponds to the size of the first microstrip line, the size of the second microstrip line and the size of the third microstrip line.

The resistance component of the impedance of the antenna also corresponds to the width of the end connected to the first feed terminal of the two ends of the first microstrip line and the width of the end connected to the second feed terminal of the two ends of the second microstrip line. The reactance component of the impedance of the antenna corresponds to the length between two ends of the first microstrip line, the length between two ends of the second microstrip line and the length between two ends of the third microstrip line.

A radio frequency identification tag antenna according to another aspect of the present invention includes a polyhedral first dielectric, a first microstrip line, a second microstrip line, a polyhedral second dielectric and a third microstrip line. The first dielectric includes a first face corresponding to the ground plane and a second face not in contact with the first face. The first microstrip line is formed in a region of a portion of the second face and has two ends. The second microstrip line is formed in an area of a portion of the second face and has two ends. The second dielectric includes a region on a portion of the second surface, a region on a portion of the first microstrip line, and a third surface on contact with a region on the portion of the second microstrip line, and a fourth surface, not on the third surface; And laminated on the first dielectric. The third microstrip line is formed in an area of all or part of the fourth surface. One of the two ends of the first microstrip line and one of the two ends of the second microstrip line face each other.

At this time, either one of the first microstrip line or the second microstrip line is the same width of the two ends.

In addition, either one of the first microstrip line or the second microstrip line has a different width at the two ends.

In addition, each of the first microstrip line and the second microstrip line has a different width at the two ends, and the smaller end of the two ends of the first microstrip line and the two ends of the second microstrip line. The smaller ends face each other.

In addition, the third microstrip line has a curved shape in the circumference.

In addition, the third microstrip line has a polygonal circumference.

In addition, the third microstrip line is formed in a ring shape.

In addition, the radio frequency identification tag antenna is formed on a fifth surface connecting the first surface and the second surface, the first shorting plate for connecting the first microstrip line and the ground plane to short the first microstrip line from the ground plane and And a second shorting plate formed on a sixth surface connecting the first surface and the second surface, and connecting the second microstrip line and the ground surface to short the second microstrip line from the ground surface.

The tag antenna according to the present invention can maximize the recognition distance of the RFID tag by allowing the electromagnetic waves transmitted from the RFID reader to be efficiently transmitted to the RFID tag chip without loss through impedance matching with the RFID tag chip.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

A radio wave identification tag according to an embodiment of the present invention will now be described with reference to the drawings.

First, an RFID system according to an embodiment of the present invention will be described with reference to FIG. 1.

1 is a diagram showing the configuration of an RFID system according to an embodiment of the present invention.

As shown in FIG. 1, the RFID system transmits a question signal that modulates continuous electromagnetic waves having a specific frequency, and receives an RFID reader 100 and an RFID reader 100 that receive a response signal corresponding to the transmitted question signal. The RFID tag 200 receives the question signal sent by the transmitter and transmits the response signal obtained by backscattering modulation of the received signal to the RFID reader 100. In this case, each of the question signal and the response signal corresponds to a radio frequency signal (hereinafter, also referred to as an RF signal).

The RFID reader 100 includes a transmitter 110, a receiver 130, and a reader antenna 150. The transmitter 110 transmits a question signal to the RFID tag 200 through the reader antenna 150, and the receiver 130 receives a response signal transmitted from the RFID tag 200 through the reader antenna 150. In this case, the reader antenna 150 is electrically connected to each of the transmitter 110 and the receiver 130.

The RFID tag 200 includes a tag antenna 210, a front end 230, and a signal processor 250. The tag antenna 210 receives the question signal transmitted by the RFID reader 100 and transmits the received question signal to the front end 230, and the front end 230 transmits the signal received from the tag antenna 210 to the direct current. The signal processor 250 converts the voltage to supply power required for the operation, and extracts the baseband signal from the question signal corresponding to the RF signal. The signal processor 250 receives the baseband signal from the front end 230, and backscatters modulates the input signal to transmit the response signal corresponding to the question signal transmitted by the RFID reader 100 to the RFID reader 100. send.

In this case, in order to improve the recognition distance of the RFID system, the tag antenna 210 should be able to efficiently transmit the signal received to the front end 230 with little loss. To this end, the impedance of the tag antenna 210 should be conjugate matched with the impedance of the front end 230.

Next, an equivalent circuit of a tag antenna and a front end according to an exemplary embodiment of the present invention will be described with reference to FIG. 2.

2 is an equivalent circuit diagram of a tag antenna and a front end according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the entire equivalent circuit consists of a voltage source V _oc , the impedance Z _a of the tag antenna and the impedance Z _c of the front end. In this case, the voltage source V _oc and the impedance Z _a of the tag antenna are equivalent circuits of the tag antenna 210, and the impedance Z _c of the front end is an equivalent circuit of the front end 230.

Impedance of the tag antenna (Z _a) has a resistance component (R _a) and the reactance component (X _a), the impedance of the front-end (Z _c) has a resistance component (R _c) and the reactance component (X _c).

At this time, when the impedance (Z _a ) of the tag antenna and the impedance (Z _c ) of the front end is conjugately matched, the maximum power is transmitted from the tag antenna 210 to the front end 230. Conjugated matching is such that, for two complex impedances, the magnitude of the absolute value of the impedance is the same and the phases have opposite signs. The impedance Z _a of the tag antenna and the impedance Z _c of the front end may be conjugately matched according to Equation 1.

At this time, when the RFID tag 200 is a passive type, the front end 230 is composed of a rectification and detection circuit using a diode, and does not include a separate matching circuit. Therefore, the impedance (Z _c ) of the front end has a complex impedance different from the usual 50Ω, and due to the characteristics of the rectifying and detecting circuit, the small resistance component (R _c ) and the large size in the ultra high frequency (UHF) band are large. It has a capacitive reactance component (X _c ).

The impedance Z _c of the front end as described above and the impedance Z _a of the tag antenna for conjugate matching must have a small resistance component Ra and _a large inductive reactance component X _a .

Next, an RFID tag according to an embodiment of the present invention will be described with reference to FIG. 3 or 4.

3 is a diagram illustrating a configuration of an RFID tag according to an embodiment of the present invention.

As shown in FIG. 3, the RFID tag includes a radio frequency identification tag chip (hereinafter referred to as an 'RFID tag chip') 10 and a tag antenna 300 including a front end and a signal processor. Include.

The tag antenna 300 includes two dielectric substrates 311 and 313, three microstrip lines 331, 333 and 335, two shorting plates 351 and 353 and two feed terminals 371 and 373. do.

In this case, a first microstrip line 331, a second microstrip line 333, a first feed terminal 371, and a second feed are formed on the top surface of the first dielectric substrate 311 among the two dielectric substrates 311 and 313. The terminal 373 and the RFID tag chip 10 are formed, and two of the four side surfaces of the first dielectric substrate 311 have two shorting plates, that is, the first shorting plate 351 and the second shorting plate ( 353) is formed.

In addition, a third microstrip line 335 is formed on the top surface of the second dielectric substrate 313 among the two dielectric substrates 311 and 313, and the bottom surface of the second dielectric substrate 313 is the first dielectric substrate 311. The tag antenna 300 is formed by stacking the first dielectric substrate 311 and the second dielectric substrate 313 by contacting a portion of the upper surface of the tag antenna 300.

The first dielectric substrate 311 has a rectangular parallelepiped shape, and a bottom surface thereof corresponds to a ground plane.

The first microstrip line 331 is formed in a rectangular shape in a region of the upper surface of the first dielectric substrate 311, that is, in the left region of the upper surface so as to contact the left side of the first dielectric substrate 311 in the drawing. . At this time, one end of the first microstrip line 331 is short-circuited by the first shorting plate 351 formed on the left side of the first dielectric substrate 311, and the other end thereof is opened.

The second microstrip line 333 is formed in a rectangular shape in a region of the upper surface of the first dielectric substrate 311, that is, in the left region of the upper surface so as to contact the right side of the first dielectric substrate 311 in the drawing. . At this time, one end of the second microstrip line 333 is shorted by the second shorting plate 353 formed on the right side of the first dielectric substrate 311, and the other end thereof is opened.

At this time, the open end of the first microstrip line 331 and the open end of the second microstrip line 333 face each other at the center of the first dielectric substrate 311.

The first shorting plate 351 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 311, that is, on the left side of the first dielectric substrate 311 in the drawing, and the first dielectric substrate ( A ground surface corresponding to the bottom surface of 311 and the first microstrip line 331 are connected to short the first microstrip line 331 from the ground plane.

The second shorting plate 353 has a rectangular shape and is formed on one side of four sides of the first dielectric substrate 311, that is, on the right side of the first dielectric substrate 311 in the drawing, and the first dielectric substrate ( The second microstrip line 333 is shorted from the ground plane by connecting the ground plane corresponding to the bottom surface of 311 and the second microstrip line 333.

The first feed terminal 371 is formed in a portion of an upper surface of the first dielectric substrate 311, and is electrically connected to the first microstrip line 331 in contact with an open end of the first microstrip line 331. .

The second feed terminal 373 is formed in a portion of an upper surface of the first dielectric substrate 311, and is electrically connected to the second microstrip line 333 in contact with an open end of the second microstrip line 333. do.

In this case, the first feed terminal 371 and the second feed terminal 373 are formed between the open end of the first microstrip line 331 facing each other and the open end of the second microstrip line 333. An RFID tag chip 10 is formed between the feed terminal 371 and the second feed terminal 373.

The second dielectric substrate 313 is in the shape of a rectangular parallelepiped, the lower surface of which is a region of a portion of the upper surface of the first dielectric substrate 311, a region of a portion of the first microstrip line 331, and the second microstrip line 333. A part of the area, the first feed terminal 371, the second feed terminal 373 and the RFID tag chip 10 in contact with.

The third microstrip line 335 is formed on the top surface of the second dielectric substrate 313 in a rectangular shape, and both ends thereof are open. At this time, the ground plane for the third microstrip line 335 does not exist, and the first microstrip line 331 and the second microstrip line 333 serve as the ground plane of the third microstrip line 335. do.

At this time, the third microstrip line 335 serves as an open stub connected in parallel to the first feed terminal 371 and the second feed terminal 373, and the two feed terminals 371 and 373 are connected to each other. Add capacitive reactance together. If the size of the third microstrip line 335 is sufficiently small compared to the wavelength corresponding to the operating frequency of the tag antenna 300, the same effect is obtained by simply connecting a flat capacitor in parallel to both ends of the feed terminal. . Through this, the tag antenna 300 may easily match impedance with the front end included in the RFID tag chip 10 through the third microstrip line 335.

4 is a plan view of an RFID tag according to an embodiment of the present invention.

As shown in FIG. 4, each of the first microstrip line 331, the second microstrip line 333, and the third microstrip line 335 of the tag antenna 300 has a width and a length.

The resistance component Ra of the impedance Z _a of the tag antenna 300 may include a width 331 _a of the first microstrip line 331, a width 333 a of the second microstrip line 333, and a first dielectric. It is determined by the dielectric loss rate of the substrate 311 and the dielectric loss rate of the second dielectric substrate 313, the reactance component (X _a ) is the length 331b and characteristic impedance of the first microstrip line 331, the second micro The length 333b and the characteristic impedance of the strip line 333 and the length 335b and the characteristic impedance of the third microstrip line 335 are determined.

In this case, since the radiation resistance of the tag antenna 300 is greatly influenced by the widths of the respective open ends of the first microstrip line 331 and the second microstrip line 333, the tag antenna 300. ), the impedance (Z _a) the resistance component (R _a) of the is mainly determined by the width (333a) of the width (331a) and the second microstrip line 333 of the first microstrip line 331. That is, the width (333a) of the impedance (Z _a) the resistance component (R _a) the size of the first microstrip line 331, the width (331a) and the second microstrip line 333 of the tag antenna 300, Increases as it increases. And the resistance component (R _a) of the impedance of the tag antenna (300) (Z _a) is increased the greater the dielectric loss factor of the dielectric loss factor and the second dielectric substrate 313 of the first dielectric substrate (311).

In addition, the reactance component X _a of the impedance Z _a of the tag antenna 300 includes the length 331b of the first microstrip line 331, the characteristic impedance, and the length 333b of the second microstrip line 333. It is mainly determined by the characteristic impedance and. That is, the magnitude of the reactance component X _a of the impedance Z _a of the tag antenna 300 is greater in the characteristic impedance of each of the first microstrip line 331 and the second microstrip line 333. The length of each of the microstrip line 331 and the second microstrip line 333 increases.

In design, the size of the first microstrip line 331 and the second microstrip line are conjugated to match the impedance of the tag antenna 300 with the impedance Z _c of the front end included in the RFID tag chip 10. The size of 333 can be adjusted.

However, when the sizes of the first microstrip line 331 and the second microstrip line 333 are limited in order to miniaturize the tag antenna 300, the reactance component required for conjugate matching with the impedance Z _c of the front end is required. There is a problem that the size of (X _a ) cannot be obtained.

In this case, a slot may be formed in the microstrip line to obtain a reactance component having a desired size using a short microstrip line. However, unnecessary radiation occurs in the formed slot and thus the tag antenna 300 may be formed. ) May cause a problem that the radiation efficiency of the decrease.

In the embodiment of the present invention, by adding a capacitive reactance in parallel to the first feed terminal and the second feed terminal using the third microstrip line 335, the size of the reactance component X _a required due to the size limitation is reduced. Solve problems you cannot get. In this case, the magnitude of the reactance component X _a of the impedance of the tag antenna 300 is 0.5 times the wavelength (Wavelength) of which the length 335b of the third microstrip line 335 corresponds to the operating frequency of the tag antenna 300. The longer the value is, the longer the characteristic impedance of the third microstrip line 335 increases.

In this case, although the length 331b of the first microstrip line 331 and the length 333b of the second microstrip line 333 are shown to be the same, they may be set differently in some cases.

In the drawing, the width 331a of the first microstrip line 331 and the width 333a of the second microstrip line 333 are shown to be the same, but may be set differently in some cases.

Next, an RFID tag according to another embodiment of the present invention will be described with reference to FIG. 5.

5 is a diagram illustrating an RFID tag according to another embodiment of the present invention.

As shown in FIG. 5, an RFID tag according to another embodiment of the present invention includes an RFID tag chip 10 and a tag antenna 400.

Tag antenna 400 includes two dielectric substrates 411, 413, three microstrip lines 431, 433, 435, two shorting plates 451, 453, and two feed terminals 471, 473. do.

At this time, a first microstrip line 431, a second microstrip line 433, a first feed terminal 471, and a second feed are formed on the top surface of the first dielectric substrate 411 among the two dielectric substrates 411 and 413. A terminal 473 and an RFID tag chip 10 are formed, and two of the four side surfaces of the first dielectric substrate 411 have two shorting plates, that is, a first shorting plate 451 and a second shorting plate ( 453) is formed.

In addition, a third microstrip line 435 is formed on the top surface of the second dielectric substrate 413 among the two dielectric substrates 411 and 413, and the bottom surface of the second dielectric substrate 413 is the first dielectric substrate 411. By contacting a portion of the upper surface of the tag antenna 400 is formed in a structure in which the first dielectric substrate 411 and the second dielectric substrate 413 are stacked.

The first dielectric substrate 411 has a rectangular parallelepiped shape, and a bottom surface thereof corresponds to a ground plane.

The first microstrip line 431 has a predetermined specific polygonal shape, that is, a shape such as '├', a region of a portion of the upper surface of the first dielectric substrate 411, that is, the left side surface of the first dielectric substrate 411 in the drawing. It is formed in the left region of the upper surface to contact with. At this time, one end of the first microstrip line 431 is shorted by the first shorting plate 451 formed on the left side of the first dielectric substrate 411, and the other end thereof is opened.

The second microstrip line 433 is a region of a portion of the upper surface of the first dielectric substrate 411 in a predetermined specific polygonal shape, that is, a shape such as '┫', that is, the right side surface of the first dielectric substrate 411 in the drawing. It is formed in the left region of the upper surface to contact with. At this time, one end of the second microstrip line 433 is short-circuited by the second shorting plate 453 formed on the right side of the first dielectric substrate 411, and the opposite end is opened.

At this time, the open end of the first microstrip line 431 and the open end of the second microstrip line 433 face each other at the center of the first dielectric substrate 411.

The first shorting plate 451 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 411, that is, on the left side of the first dielectric substrate 411 in the drawing, and the first dielectric substrate ( The first microstrip line 431 is shorted from the ground plane by connecting the ground plane corresponding to the bottom surface of the 411 and the first microstrip line 431.

The second shorting plate 453 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 411, that is, on the right side of the first dielectric substrate 411 in the drawing, and the first dielectric substrate ( The second microstrip line 433 may be shorted from the ground plane by connecting the second microstrip line 433 to the ground plane corresponding to the bottom surface of the 411.

The first feed terminal 471 is formed in a region of a portion of the upper surface of the first dielectric substrate 411 and is electrically connected to the first microstrip line 431 in contact with an open end of the first microstrip line 431. .

The second feed terminal 473 is formed in a portion of an upper surface of the first dielectric substrate 411 and is electrically connected to the second microstrip line 433 in contact with an open end of the second microstrip line 433. do.

In this case, the first feed terminal 471 and the second feed terminal 473 are formed between the open end of the first microstrip line 431 facing each other and the open end of the second microstrip line 433. An RFID tag chip 10 is formed between the feed terminal 471 and the second feed terminal 473.

The second dielectric substrate 413 is in the shape of a rectangular parallelepiped, the lower surface of which is a region of a portion of the upper surface of the first dielectric substrate 411, a region of a portion of the first microstrip line 431, and a second microstrip line 433. In contact with the area of the portion, the first feed terminal 471, the second feed terminal 473 and the RFID tag chip 10.

The third microstrip line 435 is formed in a region of the upper surface of the second dielectric substrate 413 in a predetermined specific shape, that is, a specific shape whose outline is curved, and both ends thereof are open. At this time, the ground plane for the third microstrip line 435 does not exist, and the first microstrip line 431 and the second microstrip line 433 serve as the ground plane of the third microstrip line 435. do.

Next, an RFID tag according to another embodiment of the present invention will be described with reference to FIG. 6.

6 is a diagram illustrating an RFID tag according to another embodiment of the present invention.

As shown in FIG. 6, an RFID tag according to another embodiment of the present invention includes an RFID tag chip 10 and a tag antenna 500.

The tag antenna 500 includes two dielectric substrates 511 and 513, three microstrip lines 531, 533 and 535, two shorting plates 551 and 553 and two feed terminals 571 and 573. Include.

At this time, the first microstrip line 531, the second microstrip line 533, the first feed terminal 571, and the second feed are formed on the upper surface of the first dielectric substrate 511 among the two dielectric substrates 511 and 513. The terminal 573 and the RFID tag chip 10 are formed, and two of the four side surfaces of the first dielectric substrate 511 have two shorting plates, that is, the first shorting plate 551 and the second shorting plate ( 553) is formed.

In addition, a third microstrip line 535 is formed on the top surface of the second dielectric substrate 513 among the two dielectric substrates 511 and 513, and the bottom surface of the second dielectric substrate 513 is the first dielectric substrate 511. The tag antenna 500 is formed by stacking the first dielectric substrate 511 and the second dielectric substrate 513 by contacting a portion of the upper surface of the tag antenna 500.

The first dielectric substrate 511 has a rectangular parallelepiped shape, and a bottom surface thereof corresponds to a ground plane.

The first microstrip line 531 is a predetermined specific polygonal shape, that is, a hexagonal shape of a specific shape, and a region of a portion of the upper surface of the first dielectric substrate 511, that is, the left side surface of the first dielectric substrate 511 in the drawing. It is formed in the left region of the upper surface to abut. At this time, one end of the first microstrip line 531 is shorted by the first shorting plate 551 formed on the left side of the first dielectric substrate 511, and the other end thereof is opened.

The second microstrip line 533 is a predetermined specific polygonal shape, that is, a hexagonal shape of a specific shape, a region of a portion of the upper surface of the first dielectric substrate 511, that is, the right side of the first dielectric substrate 511 on the drawing. It is formed in the left region of the upper surface to contact the side. At this time, one end of the second microstrip line 533 is short-circuited by the second shorting plate 553 formed on the right side of the first dielectric substrate 511, and the other end is opened.

In this case, the open end of the first microstrip line 531 and the open end of the second microstrip line 533 face each other at the center of the first dielectric substrate 511.

The first shorting plate 551 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 511, that is, on the left side of the first dielectric substrate 511 in the drawing, and the first dielectric substrate ( The first microstrip line 531 is shorted from the ground plane by connecting the ground plane corresponding to the bottom surface of the 511 and the first microstrip line 531.

The second shorting plate 553 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 511, that is, on the right side of the first dielectric substrate 511 in the drawing, and the first dielectric substrate ( The second microstrip line 533 may be shorted from the ground plane by connecting the second microstrip line 533 to the ground plane corresponding to the bottom surface of the 511.

The first feed terminal 571 is formed in a portion of an upper surface of the first dielectric substrate 511 and is electrically connected to the first microstrip line 531 in contact with an open end of the first microstrip line 531. .

The second feed terminal 573 is formed in a portion of an upper surface of the first dielectric substrate 511 and is electrically connected to the second microstrip line 533 in contact with an open end of the second microstrip line 533. .

In this case, the first feed terminal 571 and the second feed terminal 573 are formed between the open end of the first microstrip line 531 facing each other and the open end of the second microstrip line 533. An RFID tag chip 10 is formed between the first feed terminal 571 and the second feed terminal 573.

The second dielectric substrate 513 is in the shape of a rectangular parallelepiped, the bottom surface of which is a part of the upper surface of the first dielectric substrate 511, a part of the part of the first microstrip line 531, and the second microstrip line 533. A portion of the area, the first feed terminal 571, the second feed terminal 573 and the RFID tag chip 10 in contact with.

The third microstrip line 535 is formed in a region of the upper surface of the second dielectric substrate 513 in a predetermined specific shape, that is, an annular curved shape, and both ends thereof are open. At this time, the ground plane for the third microstrip line 535 does not exist, and the first microstrip line 531 and the second microstrip line 533 serve as the ground plane of the third microstrip line 535. do.

Next, an RFID tag according to another embodiment of the present invention will be described with reference to FIG. 7.

7 is a diagram illustrating an RFID tag according to another embodiment of the present invention.

As shown in FIG. 7, the RFID tag according to another embodiment of the present invention includes an RFID tag chip 10 and a tag antenna 600.

The tag antenna 600 includes two dielectric substrates 611, 613, three microstrip lines 631, 633, 635, two shorting plates 651, 653, and two feed terminals 671, 673. do.

In this case, a first microstrip line 631, a second microstrip line 633, a first feed terminal 671, and a second feed are formed on an upper surface of the first dielectric substrate 611 among the two dielectric substrates 611 and 613. The terminal 673 and the RFID tag chip 10 are formed, and two of the four side surfaces of the first dielectric substrate 611 have two shorting plates, that is, the first shorting plate 651 and the second shorting plate ( 653).

In addition, a third microstrip line 635 is formed on the upper surface of the second dielectric substrate 613 among the two dielectric substrates 611 and 613, and the lower surface of the second dielectric substrate 613 is the first dielectric substrate 611. The tag antenna 600 is formed by stacking a first dielectric substrate 611 and a second dielectric substrate 613 by contacting a portion of the upper surface of the tag antenna 600.

The first dielectric substrate 611 has a rectangular parallelepiped shape, and a bottom surface thereof corresponds to a ground plane.

The first microstrip line 631 has a predetermined specific polygonal shape, i.e., a specific pentagonal shape, so as to contact a region of a portion of the upper surface of the first dielectric substrate 611, that is, the left side of the first dielectric substrate 611 in the drawing. It is formed in the left region of the upper surface. At this time, one end of the first microstrip line 631 is short-circuited by the first shorting plate 651 formed on the left side of the first dielectric substrate 611, and the opposite end is opened.

The second microstrip line 633 has a predetermined specific polygonal shape, i.e., a specific pentagonal shape, so as to contact a region of a portion of the upper surface of the first dielectric substrate 611, that is, the right side of the first dielectric substrate 611 in the drawing. It is formed in the left region of the upper surface. At this time, one end of the second microstrip line 633 is short-circuited by the second shorting plate 653 formed on the right side of the first dielectric substrate 611, and the other end thereof is opened.

At this time, the open end of the first microstrip line 631 and the open end of the second microstrip line 633 face each other at the center of the first dielectric substrate 611.

The first shorting plate 651 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 611, that is, on the left side of the first dielectric substrate 611 in the drawing, and the first dielectric substrate ( The first microstrip line 631 is short-circuited from the ground plane by connecting the ground plane corresponding to the bottom surface of 611 and the first microstrip line 631.

The second shorting plate 653 is formed in a rectangular shape on one side of four sides of the first dielectric substrate 611, that is, on the right side of the first dielectric substrate 611 in the drawing, and the first dielectric substrate ( The second microstrip line 633 is shorted from the ground plane by connecting the second microstrip line 633 and the ground plane corresponding to the bottom surface of the 611.

The first feed terminal 671 is formed in a portion of an upper surface of the first dielectric substrate 611 and is electrically connected to the first microstrip line 631 in contact with an open end of the first microstrip line 631. .

The second feed terminal 673 is formed in a portion of an upper surface of the first dielectric substrate 611 and is electrically connected to the second microstrip line 633 in contact with an open end of the second microstrip line 633. .

At this time, the first feed terminal 671 and the second feed terminal 673 is formed between the open end of the first microstrip line 631 and the open end of the second microstrip line 633 facing each other, the first An RFID tag chip 10 is formed between the feed terminal 671 and the second feed terminal 673.

The second dielectric substrate 613 is in the shape of a rectangular parallelepiped, and the bottom surface thereof is a region of a portion of the upper surface of the first dielectric substrate 611, a region of a portion of the first microstrip line 631, and the second microstrip line 633. Abut the area of the part.

The third microstrip line 635 is formed in a region of the upper surface of the second dielectric substrate 613 in a predetermined specific shape, that is, a specific shape of which the outline is curved, and both ends thereof are open. At this time, the ground plane for the third microstrip line 635 does not exist, and the first microstrip line 631 and the second microstrip line 633 serve as the ground plane of the third microstrip line 635. do.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a diagram showing the configuration of an RFID system according to an embodiment of the present invention.

2 is an equivalent circuit diagram of a tag antenna and a front end according to an exemplary embodiment of the present invention.

3 is a diagram illustrating a configuration of an RFID tag according to an embodiment of the present invention.

4 is a plan view of an RFID tag according to an embodiment of the present invention.

5 is a diagram illustrating an RFID tag according to another embodiment of the present invention.

6 is a diagram illustrating an RFID tag according to another embodiment of the present invention.

7 is a diagram illustrating an RFID tag according to another embodiment of the present invention.

Claims (13)

A radio frequency identification tag comprising an antenna for receiving a question signal corresponding to a radio frequency signal and a chip for generating a response signal corresponding to the question signal, The antenna is A first dielectric having a polyhedron shape including a first surface corresponding to the ground plane and a second surface not in contact with the first surface; A first microstrip line formed in a region of a portion of the second surface and having two ends; A second microstrip line formed in a portion of the second surface and having two ends; A polyhedral second dielectric comprising a third surface in contact with a region of a portion of the second surface and a fourth surface not in contact with the third surface, and laminated on the first dielectric; And And a third microstrip line formed on said fourth side and having two ends. The method of claim 1, The antenna is A first feed terminal connected to one of two ends of the first microstrip line; And And a second feed terminal connected to one of two ends of the second microstrip line, The chip is Is formed in a portion of the second surface is in contact with the third surface, is electrically connected to the first microstrip line through the first feed terminal, the second microstrip line through the second feed terminal A radio identification tag that is electrically connected to the The method of claim 2, Each of the impedance of the antenna and the impedance of the chip comprises a resistance component and a reactance component, The value of the resistance component of the impedance of the antenna and the value of the resistance component of the impedance of the chip have the same magnitude and sign, And a value of the reactance component of the impedance of the antenna and the value of the reactance component of the impedance of the chip are equal in magnitude and opposite in sign. The method of claim 3, And the impedance of the antenna corresponds to the size of the first microstrip line, the size of the second microstrip line and the size of the third microstrip line. The method of claim 4, wherein The resistance component of the impedance of the antenna is A width of an end connected to the first feed terminal of two ends of the first microstrip line and a width of an end connected to the second feed terminal of two ends of the second microstrip line, The reactance component of the impedance of the antenna is A radio wave identification tag corresponding to a length between two ends of the first microstrip line, a length between two ends of the second microstrip line, and a length between two ends of the third microstrip line. A first dielectric having a polyhedron shape including a first surface corresponding to the ground plane and a second surface not in contact with the first surface; A first microstrip line formed in a region of a portion of the second surface and having two ends; A second microstrip line formed in a portion of the second surface and having two ends; A third surface in contact with a region of a portion of the second surface, a region in a portion of the first microstrip line, and a fourth surface in contact with a region of the portion of the second microstrip line, and a fourth surface not in contact with the third surface; A polyhedral second dielectric stacked on the first dielectric; And A third microstrip line formed in an area of all or part of the fourth surface, And a radio frequency identification tag antenna in which one of the two ends of the first microstrip line and one of the two ends of the second microstrip line face each other. The method of claim 6, Wherein either one of the first microstrip line or the second microstrip line has the same width at both ends. The method of claim 6, Any one of the first microstrip line or the second microstrip line has a radio frequency identification tag antenna having two ends having different widths. The method of claim 8, Each of the first microstrip line and the second microstrip line has different widths of two ends, And a smaller end of two ends of the first microstrip line and a smaller end of two ends of the second microstrip line facing each other. The method of claim 6, And the third microstrip line has a curved perimeter. The method of claim 6, The third microstrip line is a radio frequency identification tag antenna having a polygonal circumference. The method according to claim 10 or 11, wherein And the third microstrip line is formed in a ring shape. The method of claim 6, A first shorting plate formed on a fifth surface connecting the first surface and the second surface, and connecting the first microstrip line and the ground surface to short the first microstrip line from the ground surface; And A second shorting plate formed on a sixth surface connecting the first surface and the second surface, and connecting the second microstrip line and the ground surface to short the second microstrip line from the ground surface; Radio identification tag antenna further comprising.

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