TWI536673B - Dipole antenna for rfid tag - Google Patents

Description

Dipole antenna for wireless radio frequency

The present disclosure relates to a dipole antenna for a radio frequency, and more particularly to a dipole antenna having a loop that increases the magnetic flux area and conjugate matching required high inductance values.

Radio Frequency Identification (RFID) is a rapidly evolving technology in recent years. It consists of a reader (Reader), an electronic tag (Tag), and an antenna (Antenna). The paper of this technology was first proposed in 1948, but at the time of the technical level, there is no way to fully present it, until now it is really applied to real life.

Currently the most common applications such as transportation, library management, security systems, medical applications, etc. The frequency bands used in this system are mainly low frequency (125KHz), high frequency (13.56MHz), ultra high frequency (860~960MHz) and microwave (2.4~2.483GHz and 5.72~5.87GHz).

Radio Frequency Identification (RFID) is an important technology in the identification industry and has a variety of applications. RFID tags or tags are widely used to associate objects with identification codes. For example, RFID tags have been used for access control of buildings, security locks for vehicles, and tracking of inventory.

The information stored on the RFID tag identifies the person who wishes to enter the building with the security facility or an inventory item with a unique identification number. RFID tags retain and transmit enough information to uniquely identify individuals, packages, inventory, and more. In general, in RFID systems, to capture from RFID tags Information, RFID readers can transmit an excitation signal to an RFID tag using radio frequency (RF) backscatter. The excitation signal excites the RFID tag, which in turn backscatters the stored information to the reader. The reader then receives the information from the RFID tag and decodes it.

RFID tags can generally include a wafer for data processing and an antenna for data communication. In the RFID industry, an important system is that the RFID tag effectively receives or uses the energy received from the RFID reader to facilitate subsequent responses to the reader or to increase the available radio range in which the tag can communicate wirelessly with the reader. Efficiency can be improved by impedance matching between the RFID tag's wafer and the antenna.

Since the wafer generally exhibits a relatively high capacitive reactance, the antenna can be designed to have a relatively high inductive reactance to achieve conjugate matching. However, such high inductance may reduce the bandwidth of the RFID tag. Moreover, the material of the substrate carrying the RFID tag may cause a change in the desired inductive reactance of the tag. Moreover, the capacitive reactance of the wafer may vary due to the semiconductor process.

Therefore, it is preferable to have an RFID tag antenna capable of forming a complex conjugate with a corresponding wafer. Moreover, it is preferable to increase the bandwidth of the RFID tag while achieving a complex conjugate of impedance matching between the tag antenna and the wafer.

At present, the ultra-high frequency (UHF) frequency band operating at 902~928MHZ is most expected and paid attention by the industry, because it has a long reading distance, a larger data transmission rate and a smaller label size when working in UHF. The operating bandwidth of RFID varies from country to country, with operating bandwidths ranging from 902 to 928 MHz in North and South America, and 922 to 928 MHz in Taiwan.

A suitable tag antenna must have some characteristics, first of all must be Small enough to attach or adhere to the object being identified, and usually requires omnidirectional or semi-omnidirectional, good enough impedance matching, and requires linear polarization or dual polarization in the application, the structure must Not easily damaged and destroyed, and the most important thing is that it must be very cheap. Due to the limited size of the innate, the relatively narrow impedance bandwidth (about 2% in the case of VSWR < 2).

The present disclosure provides a dipole antenna for a radio frequency radio, comprising a first conductive element on a substrate and a second conductive element on the substrate.

The first conductive element includes a first path extending between a first end and a second end, a second path extending from the first end to a third end, and extending from the first end to the first end A third path between the fourth ends.

The second conductive element includes a fourth path extending between a fifth end and a sixth end. In addition, a first gap is formed between the second end and the fifth end, and a second gap is disposed between the third end and the sixth end, and the first gap is configured to determine a frequency of the dipole antenna. At least one of a width or a coupling amount.

The length of the third path of the present disclosure is a quarter wavelength.

The first path and the third path of the present disclosure form a length configured to determine a resistance of the dipole antenna.

The first path and the second path of the present disclosure form a width configured to determine an inductive reactance of the dipole antenna.

The first gap of the present disclosure is configured to determine at least one of a bandwidth or a coupling amount of the dipole antenna.

The third path of the present disclosure includes a meandering structure.

The third end configuration of the present disclosure is electrically connected to one of the first pins of a wafer, and the sixth end is configured to be electrically connected to one of the second pins of the wafer.

The present disclosure further provides a dipole antenna for a radio frequency, comprising a first path on a substrate, a second path on the substrate, a third path on the substrate, and a third path on the substrate. A fourth path.

The first path extends between a first end and a second end, and the second path extends between the first end and a third end, the third path having a length of a quarter wavelength and extending Between one end and a fourth end, the fourth path extends between a fifth end and a sixth end, and the second end and the fifth end have a first gap, the third end and the sixth end There is a second gap between the ends.

The second path and the third path form a length configured to determine a resistance of the dipole antenna. The first path and the second path form a width configured to determine an inductive reactance of the dipole antenna.

The disclosure further includes a fifth path on the substrate, the fifth path extending from a seventh end to an eighth end between the fifth end and the sixth end.

The fifth path of the present disclosure has a length of a quarter wavelength.

The first gap of the present disclosure is configured to determine at least one of a bandwidth or a coupling amount of the dipole antenna. And the third path includes a meandering structure.

The third end configuration of the present disclosure is electrically connected to one of the first pins of a wafer, and the fifth end is configured to be electrically connected to one of the second pins of the wafer.

The present disclosure further provides a dipole antenna for a radio frequency, comprising a first conductive element on a substrate and a second conductive element on the substrate.

The first conductive element includes a first path extending between a first end and a second end, a second path extending from the first end to a third end, and extending from the first end to the first end A third path between the fourth ends.

The second conductive element includes a fourth path extending between a fifth end and a sixth end. a first gap is formed between the second end and the fifth end, and a second gap is disposed between the third end and the sixth end, the first gap is configured to determine a bandwidth or a coupling of the dipole antenna At least one of the quantities.

The disclosure further includes a fifth path on the substrate, the fifth path extending from a seventh end of the fifth end and the sixth end to an eighth end, the fifth path having a length of four points One wavelength.

The second path and the third path form a length configured to determine a resistance of the dipole antenna. The first path and the second path form a width configured to determine an inductive reactance of the dipole antenna. The third path has a length of a quarter wavelength.

The first path and the third path of the present disclosure form a length configured to determine a resistance of the dipole antenna.

The third end configuration of the present disclosure is electrically connected to one of the first pins of a wafer, and the sixth end is configured to be electrically connected to one of the second pins of the wafer.

The width of the first gap of the disclosure ranges from 0.01 cm to 1 Between the points.

The technical features of the present disclosure have been broadly described above, and the detailed description of the present disclosure will be better understood. Other technical features that form the subject matter of the claims of the present disclosure will be described below. It is to be understood by those of ordinary skill in the art that the present invention may be practiced otherwise. It is also to be understood by those of ordinary skill in the art that this invention is not limited to the spirit and scope of the disclosure as defined by the appended claims.

The directions discussed herein are dipole antennas for radio frequency. In order to fully understand the present disclosure, detailed steps and structures will be set forth in the following description. Obviously, the implementation of the present disclosure is not limited to the specific details familiar to those skilled in the relevant art. On the other hand, well-known structures or steps are not described in detail to avoid unnecessarily limiting the disclosure. The preferred embodiments of the present disclosure will be described in detail below, but the disclosure may be widely practiced in other embodiments, and the scope of the disclosure is not limited, which is subject to the scope of the following claims. .

The embodiments disclosed herein are incorporated in the drawings to explain the details. The "embodiment", "this embodiment", "other embodiment" and the like referred to in the specification are intended to include the specific features, structures, or characteristics described in the embodiments of the present disclosure. "In this embodiment" The phrase "a" does not necessarily refer to the same embodiment.

In addition, the components described in the claims and the description of the invention are singular unless otherwise specified. If the quantifier of the marked element is one, the quantifier contains one unit or at least one unit. If the quantifier of the labeled component is plural, the quantifier contains more than two units. If the quantifier of the marked element is not displayed, the quantifier contains one unit or more than two units.

The embodiments disclosed herein are incorporated in the drawings to explain the details. The following examples are presented to illustrate the disclosure, but the disclosure is not limited to the embodiments. Further, various embodiments may be combined as appropriate to each other to achieve other embodiments.

1 is a schematic diagram of a radio frequency identification (RFID) tag 10 in accordance with an embodiment of the present disclosure. Referring to FIG. 1, an RFID tag 10 may include a wafer 11 and an antenna 12. The wafer 11 can be coupled or fixed to the substrate 13 and electrically connected to the antenna 12 above or above the substrate 13.

Wafer 11 may include suitable electrical components, such as resistors, capacitors, inductors, batteries, memory devices, and processors to provide proper interaction with the RFID reader through antenna 12. In general, wafer 11 can exhibit a relatively high capacitive reactance (Z _C ), which can be specified by the wafer manufacturer and can be expressed as follows: Z _C = R _{C -} jX _C .

Wherein Z _C represents the real part of the resistance R _C of the wafer 11, and the imaginary part of Z _C X _C represents the capacitance of the wafer 11.

The substrate 13 can form the basis of personal identification, marking, packaging, and the like. Materials suitable for the substrate 13 may include, but are not limited to, glass, epoxy, ceramics, hard materials such as Teflon and FR4 or paper, synthetic paper, plastic and polyimide. And other organic materials. The resonant frequency of the antenna 12 can vary with changes in the material, electrical characteristics, and thickness of the substrate 13.

Antenna 12 may include an inductive material such as copper, copper alloy, aluminum, and inductive ink. An antenna pattern of the inductive material can be formed on or over the substrate 13 by an etching, deposition or printing process or other process. In general, antenna 12 can exhibit a relatively high inductive reactance (Z _L ), which can be expressed as follows: Z _L = R _L + jX _L .

Where Z _L represents the real part R _L of the radiation resistance of the antenna 12, and Z _L represents the imaginary part of the inductive reactance X _L of the antenna 12. When designing the antenna 12, it is preferable to form a complex conjugate of Z _C and Z _L while improving the bandwidth of the antenna 12.

Referring again to FIG. 1, antenna 12 can include a conductive element or more, such as first conductive element 121 and second conductive element 122.

The first conductive element 121 can include: a first path (hereinafter referred to as "first path AB") extending between the first end "A" and the second end "B"; and a second path (hereinafter referred to as " a second path AC") extending from the first end "A" to the third end "C"; and a third path (hereinafter referred to as "third path AD") extending from the first end "A" to The fourth end is "D".

The first path AB and the second path AC form a width W ₁ configured to obtain a desired inductive value, X _L . In one embodiment of the present disclosure, the value of X _L increases as the width W ₁ increases.

Moreover, the first path AB and the third path AD may form a path BAD having a length L ₁ configured to obtain a radiation resistance value required for the dipole antenna, that is, R _L . In one embodiment of the present disclosure, the value of R _L increases as the length L ₁ increases.

The third path AD is a quarter-wavelength transmission path having a length of a quarter wavelength or an odd multiple of a quarter wavelength. In this embodiment, the RFID tag 10 can accept one or more of a variety of frequencies, such as at least one of the three bands. An example of such three frequency bands may include a microwave frequency band at or near 2.45 terahertz (GHz), an ultra high frequency (UHF) band in the range of 860 megahertz (MHz) to 960 megahertz (MHz), and At or near the high frequency (HF) band of 13.65 megahertz (MHz).

In other embodiments, the RFID tag 10 can accept another or other combination of frequency bands, depending on its application or region. Antenna 12 can be configured to obtain sufficient antenna gain to transmit and receive radio waves of the desired band.

The second conductive element 122 can include a fifth end "E" and a sixth end "F", which can be used as a short-circuit point and a feed point of the RFID antenna 12, respectively, and the fifth end "E" and the sixth end "F" A fourth path EF can be formed. Moreover, the fifth end "E" of the second conductive element 122 can be separated from, but close to, one end "B" of the first path AB. In other words, the second end B and the fifth end E have a first gap d ₁ . The distance between the ends E and B is d ₁ , which can affect the coupling of the electric field, thereby affecting the bandwidth of the antenna 12. In other words, the first gap d ₁ is configured to determine at least one of a bandwidth or a coupling amount of the dipole antenna.

In an embodiment of the present disclosure, the amount of electrical coupling decreases as the distance d ₁ increases. The required bandwidth can be obtained by varying the amount of electrical coupling. The first conductive element 121 is characterized by an "open circuit" coupling to the second conductive element 122. In particular, the second conductive element 122 is "open" coupled to the end "B" of the first path AB.

In addition, the sixth end "F" of the second conductive element 122 can be electrically connected to One pin or a contact (not shown) of the wafer 11 and one end "C" of the second path AC can be electrically connected to another pin or a contact (not shown) of the wafer 11. In other words, there is a second gap between the third end C and the sixth end F.

In addition, in the embodiment shown in FIG. 1, the shape of the third path AD may be a meandering structure.

Those skilled in the art will appreciate that the antenna 12 can be designed to have a variety of antenna patterns while achieving the desired electrical characteristics, such as the desired impedance of the RFID tag 10. 2 is a schematic diagram of configuring an antenna 22 for use with the RFID tag 10 of FIG. 1 in accordance with an embodiment of the present disclosure.

Referring to FIG. 2, in this embodiment, the antenna 22 can be formed on or above the FR4 substrate having a relative dielectric constant of εr = 4.4 and a loss tangent of 0.0245, and can accept a radiation frequency of 925 megahertz (MHz).

A schematic diagram of a dipole antenna 22 as shown in FIG. The dipole antenna 22 includes a first path AB, a second path AC, a third path AD, and a fourth path EF.

The first path AB extends between a first end A and a second end B. The second path AC extends between the first end A and the third end C. The third path AD has a length of a quarter wavelength and extends between the first end A and the fourth end D. The fourth path EF extends between a fifth end E and a sixth end F. In addition, the second end B and the fifth end E have a first gap d ₁ , and the third end C and the sixth end F have a second gap d ₂ .

In the embodiment of FIG. 2, the dipole antenna 22 further includes a fifth path GH. The fifth path GH extends from the seventh end G of the fifth end E and the sixth end F to an eighth end H, and the fifth path GH is a selective path. The three paths AD are either one or coexist. Further, the length of the fifth path GH is a quarter wavelength. As shown in FIG. 2, the fifth path GH and the third path AD are both meander structures.

The body of the dipole antenna 22 shown in Fig. 2 is exemplified by 52.5 × 17.5 × 0.8 mm ³ . In other words, L is 52.5 mm, W is 17.5 mm, and thickness is 0.8 mm. Also, the lengths L ₁ and W ₁ (which may determine the radiation resistance and the inductive reactance of the dipole antenna 22, respectively) may be 26.1 mm (mm) and 15.3 mm, respectively.

The first gap d _{1 of the} open circuit (which may determine the amount of electrical coupling, which in turn determines the bandwidth of the dipole antenna 22) may be between 0.1 and 10 mm. Other parameters of the dipole antenna 22 can also be set according to their application or region.

For example, the parameter set may include W _3, 6.3mm of width W _4, 5.9mm and 3.6mm of the width W ₅ of the length of the 17.5mm width W _2, 9mm of width L _2. Moreover, the second gap d ₂ (which may depend on the pin gap of the wafer 11) may be 0.25 to 3 mm. For detailed parameters, please refer to Table 1 below:

The above parameters of the antenna 22 shown in Fig. 2 can be verified, for example, by means of a simulation software. In an embodiment, Ansoft Corporation's HFSS ^(TM) software can be used. HFSS supports three-dimensional (3D) electromagnetic field simulation of high performance electronic design.

For example, HFSS supports electromagnetic simulation of high-frequency and high-speed components and is widely used to design antennas with RF and/or microwave components, as well as embedded passive components on printed circuits, printed circuit board (PCB) interconnects, and high-frequency integrated circuits ( IC) package.

The graph is provided by a simulated software product such as HFSS. The dipole antenna can include an antenna pattern and associated parameters similar to the dipole antenna 22 shown in FIG. The capacitive reactance of the wafer decreases as the frequency increases, and the resistance of the wafer can remain constant without being affected by the frequency.

The resistance and inductive reactance of the dipole antenna 22 may vary with frequency variations at different gaps (eg, 0.5 mm, 1.0 mm, and 1.5 mm). Therefore, the conjugate impedance matching between the wafer and the antenna under each different gap can be determined. At this time, the power reflection coefficient is zero, so there is a maximum power transmission between the antenna and the wafer, which is called conjugate matching.

Since the antenna field measurement system of the current wave non-reflection chamber is designed to match the 50 Ω system, the antenna cannot be matched with the impedance of the antenna field measurement system, and the radiation field type of the tag antenna cannot be accurately measured, so the disclosure utilizes HFSS ^TM simulated radiation patterns of this antenna.

Figure 3 shows the radiation pattern of the dipole antenna simulating the YZ plane at 925 MHz. The field pattern of the YZ plane shows that there are two zeros in the positive Y direction and the negative Y direction, which means that there is reception in this direction. Not a dead end.

Due to the above experiments, the disclosure can assist the original RFID chip to obtain a farther reading distance of 2~4.5m (due to different RFID readers having different results and different FIRMWARE relationship). Therefore, designing a dipole antenna allows the original RFID chip to achieve more performance.

In summary, the disclosure is based on the design of a general RFID Tag antenna, and uses the coupling effect and the modulation antenna design parameters to optimize the antenna design. The RFID Tag is designed as a long rectangular type, which can be selected according to the physical characteristics and conditions of the object itself. The RFID tag consists of four parts: (1) RFIC chips with critical impedance values; (2) electromagnetic wave receiving units with bilateral wavelengths of 1/4 wavelength (eg path AD and path GH); (3) increased magnetic flux area for intermediates Matching the conjugate with a high inductance value of the loop antenna (such as path CAB and path EF); (4) cutting the loop antenna with a gap (for example, d ₁ ), using the coupling effect to generate a higher resistance value to facilitate conjugate Match the design. The antenna designed with the above four technologies is integrated into the RFID tag, which can realize high-efficiency long-distance RFID tags and improve the probability of successful RFID tag reading.

In describing a representative example of the present disclosure, the present specification may represent the method and/or process of the present disclosure as a specific sequence of steps. However, the scope of the method or process is not limited to the particular order of steps described. It is also possible to be familiar with the sequence of other steps as a person skilled in the art. Therefore, the specific order of steps set forth in this specification should not be construed as limiting the scope of the application. In addition, the scope of application for the method and/or process of the present disclosure should not be limited to the implementation of the order of the steps in the written form, which is readily understood by those skilled in the art, and the order can be changed and still It is covered by the spirit and scope of this disclosure.

The technical content and technical features of the present disclosure have been disclosed as above, but those skilled in the art should understand that the teachings of the present disclosure are within the spirit and scope of the disclosure as defined by the scope of the appended claims. The illustrations and disclosures can be used in various alternatives and modifications. For example, many of the devices or structures or method steps disclosed above may be implemented in different ways or substituted with other structures, or a combination of the two.

The scope of the present invention is not limited to the process, machine, manufacture, compositions, means, methods, or steps of the particular embodiments disclosed. It should be understood by those of ordinary skill in the art that, based on the teachings of the present disclosure, the process, the machine, the manufacture, the composition of the material, the device, the method, or the steps, whether present or future developers, The revealer performs substantially the same function in substantially the same manner, and achieves substantially the same result, and can also be used in the present disclosure. Accordingly, the scope of the following claims is intended to cover such <RTIgt; </ RTI> processes, machines, manufactures, compositions, devices, methods or steps.

10‧‧‧RFID tags

11‧‧‧ wafer

12‧‧‧Antenna

121‧‧‧First conductive element

122‧‧‧Second conductive element

13‧‧‧Substrate

22‧‧‧Antenna

AB‧‧‧First path

A‧‧‧ first end

B‧‧‧ second end

AC‧‧‧Second path

C‧‧‧ third end

AD‧‧‧ third path

D‧‧‧ fourth end

E‧‧‧ fifth end

F‧‧‧ sixth end

EF‧‧‧fourth path

GH‧‧‧ fifth path

G‧‧‧ seventh end

H‧‧‧ eighth end

d ₁ ‧‧‧First gap

d ₂ ‧‧‧second gap

W‧‧‧Width

W ₁ ‧‧‧Width

W ₂ ‧‧‧Width

W ₃ ‧‧‧Width

W ₄ ‧‧‧Width

W ₅ ‧‧‧Width

L‧‧‧ length

L ₁ ‧‧‧ length

L ₂ ‧‧‧ length

L ₃ ‧‧‧ length

L ₄ ‧‧‧ length

L ₅ ‧‧‧ length

L ₆ ‧‧‧ length

The foregoing summary of the invention, as well as the above detailed description For the purposes of illustrating the invention, various embodiments are shown in the drawings. However, it should be understood that the invention is not limited to the precise arrangements and devices disclosed.

1 is a schematic diagram of a radio frequency identification (RFID) tag according to an embodiment of the present invention; FIG. 2 is a schematic diagram of an antenna configured for the RFID tag shown in FIG. 1 according to an embodiment of the present invention; and FIG. A schematic diagram of a waveform of an antenna for an RFID tag at a certain open distance.

10‧‧‧RFID tags

11‧‧‧ wafer

12‧‧‧Antenna

121‧‧‧First conductive element

122‧‧‧Second conductive element

13‧‧‧Substrate

22‧‧‧Antenna

AB‧‧‧First path

A‧‧‧ first end

B‧‧‧ second end

AC‧‧‧Second path

C‧‧‧ third end

AD‧‧‧ third path

D‧‧‧ fourth end

E‧‧‧ fifth end

F‧‧‧ sixth end

EF‧‧‧fourth path

d ₁ ‧‧‧First gap

W ₁ ‧‧‧Width

L ₁ ‧‧‧ length

Claims (22)

A dipole antenna for a radio frequency, comprising: a first conductive element on a substrate, the first conductive element comprising: a first path extending between a first end and a second end; a first end extending to a second path between the third ends; and a third path extending from the first end to a fourth end; and a second conductive element on the substrate, the second The conductive component includes: a fourth path extending between a fifth end and a sixth end: and a fifth path extending from the seventh end of the fifth end and the sixth end to an eighth end The second end and the fifth end have a first gap, and the third end and the sixth end have a second gap. The dipole antenna of claim 1, wherein the length of the third path is a quarter wavelength. The dipole antenna of claim 1, wherein the first path and the third path form a length configured to determine a resistance of the dipole antenna. The dipole antenna of claim 1, wherein the first path and the second path form a width configured to determine an inductive reactance of the dipole antenna. The dipole antenna according to claim 1, wherein the first gap is configured for Determining at least one of a bandwidth or a coupling amount of the dipole antenna. The dipole antenna of claim 1, wherein the third path comprises a meandering structure. The dipole antenna of claim 1, wherein the third end is configured to be electrically coupled to a first pin of a wafer, the sixth end configured to be electrically coupled to a second pin of the wafer. A dipole antenna for a radio frequency, comprising: a first path on a substrate, the first path extending between a first end and a second end; and a second path on the substrate, the a second path extending between the first end and a third end; a third path on the substrate, the third path having a length of a quarter wavelength and extending from the first end and the fourth end a fourth path on the substrate, the fourth path extending between a fifth end and a sixth end; and a fifth path on the substrate, the fifth path from the fifth end The seventh end of the sixth end extends to an eighth end, wherein the second end and the fifth end have a first gap, and the third end and the sixth end have a second gap. The dipole antenna of claim 8, wherein the fifth path has a length of a quarter wavelength. The dipole antenna of claim 8, wherein the first path and the third path form a length configured to determine a resistance of the dipole antenna. The dipole antenna of claim 8, wherein the first path and the second path form a width configured to determine an inductive reactance of the dipole antenna. The dipole antenna of claim 8, wherein the first gap is configured to determine at least one of a bandwidth or a coupling amount of the dipole antenna. The dipole antenna of claim 8, wherein the third path comprises a meandering structure. The dipole antenna of claim 8, wherein the third end is configured to be electrically coupled to a first pin of a wafer, the fifth end configured to be electrically coupled to a second pin of the wafer. A dipole antenna for a radio frequency, comprising: a first conductive element on a substrate, the first conductive element comprising: a first path extending between a first end and a second end; a first end extending to a second path between the third ends; and a third path extending from the first end to a fourth end; and a second conductive element on the substrate, the second The conductive element includes: a fourth path extending between a fifth end and a sixth end; and a fifth path extending from the seventh end of the fifth end and the sixth end to an eighth end a second gap between the second end and the fifth end, the third end and the sixth end having a second gap configured to determine a bandwidth of the dipole antenna or At least one of a coupling amount. The dipole antenna of claim 15, wherein the fifth path has a length of a quarter wavelength. The dipole antenna of claim 15, wherein the length of the third path is a quarter wavelength. The dipole antenna of claim 15 wherein the first path and the third path form a length configured to determine a resistance of the dipole antenna. The dipole antenna of claim 15, wherein the first path and the second path form a width configured to determine an inductive reactance of the dipole antenna. The dipole antenna of claim 15 wherein the third path comprises a meandering structure. The dipole antenna of claim 15 wherein the third end is configured to be electrically coupled to a first pin of a wafer, the sixth end configured to be electrically coupled to a second pin of the wafer. The dipole antenna according to claim 15, wherein the first gap has a width ranging from 0.01 cm to 1 cm.