Antenna modules and IC cards

Abstract

To provide an antenna module 1 and an IC card capable of improving communication performance.SOLUTION: An antenna module 1 comprises: a substrate 10; a first antenna 20 provided on the substrate 10, for transmitting / receiving signals; a first IC chip 30 electrically connected to the first antenna 20; a second antenna 40 for transmitting / receiving signals in a frequency band different from that of the first antenna 20; and a second IC chip electrically connected to the second antenna. The first antenna 20 and the second antenna 40 are provided at positions not overlapping each other on the substrate 10 in a plan view. The first antenna 20 is composed of a metallic thin film arranged in a horizontal U-shaped or vertical U-shaped manner in plan view on the surface of the substrate 10 and in a region other than a region where the second antenna 40 is provided on the surface of the substrate 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an antenna module and an IC card. [Background technology]

[0002] In recent years, contactless IC cards, contact IC cards, RFID tags, etc. that use RFID (Radio Frequency Identification) technology have become widely used. Of these, contactless IC cards are convenient because they allow information to be exchanged simply by placing or holding the card over a card reader. As a result, they are used in a wide variety of fields, including transportation applications such as railway ticket gates, security systems for access control, and product management systems in factories.

[0003] Furthermore, there are two communication methods for contactless IC cards: an electromagnetic induction method that uses HF band signals to communicate with a reader, and a radio wave method that uses UHF band signals to communicate.Recently, contactless IC cards have been developed that house an HF band antenna and a UHF band antenna inside the board, enabling communication using two different communication methods with just one card (see, for example, Patent Document 1).

[0004] Contactless IC cards, especially transportation IC cards, are often used while stored in a card case, pass case, or the like. It is also common for a single user to carry multiple IC cards and use them for different purposes. For this reason, some users store multiple contactless or contact IC cards in a card case, etc. However, when multiple IC cards are stacked, the antenna characteristics of the contactless IC card change due to the influence of the antennas (metal) of the other IC cards, which can sometimes prevent proper communication with the reader. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Publication No. 2019-169902 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure has been made in light of the above-mentioned problems, and aims to provide an antenna module and an IC card that can improve communication performance. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the antenna module of the present disclosure comprises a substrate, a first antenna provided on the substrate for transmitting and receiving signals, and a first IC chip electrically connected to the first antenna, wherein the first antenna is made of a thin metal film arranged on the surface of the substrate in a U-shape or C-shape when viewed in a plane. Alternatively, the antenna module of the present disclosure comprises a substrate, a first antenna provided on the substrate for transmitting and receiving signals, a second antenna provided on the substrate for transmitting and receiving signals in a frequency band different from that of the first antenna, and an IC chip electrically connected to the first antenna and the second antenna, wherein the first antenna is made of a metal thin film arranged in a U-shape or C-shape in plan view on the surface of the substrate in an area that does not overlap with the second antenna in plan view. The IC card of the present disclosure also includes the antenna module described above. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide an antenna module and an IC card that can improve communication performance. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an exploded perspective view of an IC card equipped with an antenna module according to a first embodiment (Example 1). [Figure 2A] FIG. 2 is a plan view (surface view) of the antenna module shown in FIG. [Figure 2B] 2B is a plan view (surface view) of the first antenna shown in FIG. 2A. [Figure 3] 2 is a diagram showing dimensions of an antenna portion of the antenna module shown in FIG. 1. FIG. [Figure 4] 10 is a plan view (surface view) of an antenna module according to a modified example (embodiment 2). FIG. [Figure 5] FIG. 5 is a diagram showing dimensions of an antenna portion of the antenna module shown in FIG. [Figure 6] 1 is a plan view (surface view) of an antenna module of Comparative Example 1. FIG. [Figure 7] FIG. 7 is a diagram showing dimensions of an antenna portion of the antenna module shown in FIG. 6. [Figure 8] 10 is a diagram showing measurement results of communication performance of the antenna module of Example 1. FIG. [Figure 9] FIG. 10 is a diagram showing measurement results of communication performance of the antenna module of Example 2. [Figure 10] 10 is a diagram showing measurement results of communication performance of the antenna module of Comparative Example 1. FIG. [Figure 11] 10 is a diagram showing measurement results of RSSI of the antenna modules of Example 1, Example 2, and Comparative Example 1. FIG. [Figure 12] 10 is a diagram showing the difference in sensitivity among the antenna modules of Example 1, Example 2, and Comparative Example 1. FIG. [Figure 13] 10 is a plan view (surface view) of an antenna module according to a second embodiment (Example 3). FIG. [Figure 14] FIG. 14 is a diagram showing dimensions of the antenna portion of the antenna module shown in FIG. [Figure 15] FIG. 10 is a diagram showing measurement results of communication performance of the antenna module of Example 3. [Figure 16] 10 is a diagram showing the measurement results of RSSI of the antenna modules of Example 3 and Comparative Example 1. FIG. [Figure 17] 10 is a diagram showing the difference in sensitivity between the antenna modules of Example 3 and Comparative Example 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0011] (First embodiment) Fig. 1 is an exploded perspective view of a contactless IC card (hereinafter, sometimes simply referred to as "IC card") 100 including an antenna module 1 according to a first embodiment. Fig. 2A is a plan view (front view) of the antenna module 1 shown in Fig. 1, and Fig. 2B is a plan view (front view) of the first antenna 20 shown in Fig. 2A.

[0012] As shown in FIG. 1, the IC card 100 according to the first embodiment includes an antenna module 1 and a pair of cover sheets 2 and 3 disposed on the upper and lower surfaces of the antenna module 1. The IC card 100 is formed in a rectangular shape when viewed from above, but is not limited to a rectangular shape and can be formed in a shape that suits the type of IC card 100 and its intended use. The size of the rectangular IC card 100 may be the same as that of a typical IC card. Specifically, for example, the IC card 100 can be formed to have a longitudinal length of 85.6 mm, a lateral length of 54.0 mm, and a thickness of 0.76 mm in accordance with JIS Type II (JIS-X6301).

[0013] The pair of cover sheets 2, 3 are bonded to the upper and lower surfaces of the antenna module 1 by thermocompression or the like to protect the antenna module 1. These cover sheets 2, 3 can be, for example, insulating resin sheets or resin plates. Suitable insulating resins include, but are not limited to, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyvinyl chloride (PVC), and polyimide (PI). The pair of cover sheets 2, 3 can have, for example, a length of 85.6 mm in the x direction, a length of 54.0 mm in the y direction, and a length (thickness) of 0.1 mm in the z direction.

[0014] As shown in Figures 1 and 2A, the antenna module 1 and the cover sheets 2 and 3 are formed in a rectangular shape in a plan view. Hereinafter, for ease of explanation, the configuration of each part will be described with the longitudinal direction of the antenna module 1 and the cover sheets 2 and 3 as the x-direction, the lateral direction thereof that is perpendicular to the x-direction as the y-direction, and the stacking direction of the antenna module 1 and the cover sheets 2 and 3 that is perpendicular to the x-direction and y-direction as the z-direction, as shown in Figures 1 and 2A. Furthermore, the direction from the antenna module 1 toward one cover sheet 2 is the z-positive direction, and the direction from the antenna module 1 toward the other cover sheet 3 is the z-negative direction, and the z-positive direction may sometimes be referred to as upward and the z-negative direction as downward.

[0015] 2A, the antenna module 1 includes at least a substrate 10, a first antenna 20 for transmitting and receiving signals, and a first IC chip 30 electrically connected to the first antenna. The first antenna 20 transmits and receives signals by radio wave, for example.

[0016] Furthermore, the antenna module 1 of this embodiment includes a second antenna 40 provided on the substrate 10 for transmitting and receiving signals in a frequency band different from that of the first antenna 20, and a second IC chip 50 electrically connected to the second antenna 40. The second antenna 40 transmits and receives signals by, for example, electromagnetic induction.

[0017] The substrate 10 is rectangular in plan view and is formed with the same dimensions as or slightly smaller than the cover sheets 2 and 3. Specifically, for example, if the dimensions are the same, the length of the substrate 10 in the x direction can be 85.6 mm and the length in the y direction can be 54.0 mm. The thickness of the substrate 10 is preferably, for example, 5 μm or more and 300 μm or less, which provides the substrate with adequate strength to accommodate the first antenna 20 and the second antenna 40 and to mount the first IC chip 30 and the second IC chip 50.

[0018] It is preferable to use an insulating resin film as the material for the substrate 10. Specifically, suitable examples include a resin film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), or polyethylene (PE), either singly or as a multilayer film formed by laminating multiple of these resin films.

[0019] The first antenna 20 is provided on the surface of the substrate 10 and is formed of a metal thin film. A suitable material for the metal thin film of the first antenna 20 is, for example, an aluminum (Al) sheet (aluminum sheet), but this is not limiting. For example, the first antenna 20 can be formed by attaching an aluminum sheet to a substrate 10 made of a PET film using dry lamination or the like. FIG. 2B shows a plan view (surface view) of the first antenna 20. The solid line portion in FIG. 2B represents the first antenna 20. The first antenna 20 is provided on a substrate 10 made of a resin film or the like, shown by the dashed line, and is a planar antenna for an IC card that is carried by a person or attached to an object for purposes such as access control, logistics management, and product management for facilities. The first antenna 20 is planar (plate-like), and the surface view (plan view) and back view are depicted symmetrically. Therefore, FIG. 2B shows the plan view (surface view) of the first antenna 20, with the back view omitted. Also, because it is a planar view, the four side views sandwiched between the front and back views have been omitted.

[0020] The first antenna 20 is composed of a metal thin film arranged on the surface of the substrate 10 in a U-shape in plan view. The first antenna 20 is preferably arranged so as to cover at least 50% or more of the surface area of ​​the substrate 10, and more preferably so as to cover 60% or more of the surface area of ​​the substrate 10. Furthermore, it is preferable that the external dimensions of the first antenna 20 are approximately the same as or slightly smaller than the external dimensions of the substrate 10. Specifically, it is preferable that the external dimensions (maximum external dimensions) of the first antenna 20 in the x and y directions are approximately the same as or approximately 1 mm to 10 mm smaller than the external dimensions (maximum external dimensions) of the substrate 10 in the x and y directions.

[0021] Furthermore, the first antenna 20 preferably has a U-shape in plan view, as shown in FIG. 2A etc. That is, the first antenna 20 has a first region 21 extending in the x direction along one long side of the substrate 10, in a strip shape with a predetermined width (e.g., approximately half or more of the short side), from one short side to the other short side, and a pair of second regions 22, 23 extending in the y direction along the one and other short sides of the substrate 10 from both sides of the first region to the other long side, in a strip shape with a predetermined width (e.g., approximately ¼ or more of the long side). The second antenna 40 is disposed between the pair of second regions 22, 23. The first antenna 20 also has a first slot 24 extending in the x direction.

[0022] As described above, the first antenna 20 is disposed so as to cover, in a plan view, almost the entire area of ​​the surface of the substrate 10 except for the area where the second antenna 40 is disposed. By forming the first antenna 20 with such an area, the first antenna 20 can be made larger than conventional antennas, thereby increasing the communication distance and improving communication performance. Furthermore, even when the IC card 100 of this embodiment is used in combination with another IC card or the like, the first antenna 20 encompasses the metal parts of the antennas of the other IC cards (the antennas of the other IC cards are housed inside the outer shape of the first antenna 20), so that the characteristics of the first antenna 20, such as impedance, are not affected and excellent communication performance can be maintained.

[0023] The first antenna 20 transmits and receives signals to and from a radio wave reader or reader / writer (not shown) using radio wave technology. Signals are transmitted and received between the first antenna 20 and the reader or the like using a UHF band frequency (e.g., 920 MHz). The first antenna 20 outputs signals received from the radio wave reader or the like to the first IC chip 30.

[0024] The first IC chip 30 is mounted at a predetermined position on the first antenna 20. The first IC chip 30 stores various information such as personal identification information and item management information. The first IC chip 30 is also equipped with a predetermined arithmetic processing function, etc., and executes arithmetic processing based on commands contained in a signal input from the first antenna 20, and outputs the processing results to the first antenna 20. The first antenna 20 transmits the signal including the processing results input from the first IC chip 30 to a radio wave reader or the like.

[0025] The characteristics of the first IC chip 30 are as follows, but are not limited to these. [Impedance frequency characteristics] 866MHz: 15-j265(Ω) 915MHz: 14-j252(Ω) 953MHz: 13-j242(Ω) [Air Protocol] ISO 18000-6c

[0026] The impedance of the first antenna 20 is designed to match the impedance of the first IC chip 30 in the range of 915 to 920 MHz. Such impedance matching reduces current loss, and reducing loss increases the communication distance.

[0027] As described above, the second antenna 40 is provided between the pair of second regions 22, 23 of the first antenna 20 in a plan view. As shown in FIG. 2A , the second antenna 40 is a coil antenna in which a conductor is wound in a loop shape. A suitable material for the second antenna 40 is, for example, aluminum (Al), but the material is not limited thereto, and other conductive materials such as copper (Cu) can also be used as the material for the second antenna 40. The first antenna 20 and the second antenna 40 may be formed of the same material or different materials.

[0028] The second antenna 40 transmits and receives signals to and from an electromagnetic induction reader or reader / writer (not shown) using electromagnetic induction. Signals are transmitted and received between the second antenna 40 and the electromagnetic induction reader or the like using an HF band frequency (e.g., 13.56 MHz). A signal received by the second antenna 40 from the electromagnetic induction reader or the like is output to the second IC chip 50. The air protocol of the second IC chip 50 connected to the second antenna 40 may be, for example, ISO 14443 Type A, but is not limited to this and may be ISO 14443 Type B or ISO 15693.

[0029] Similar to the first IC chip 30, the second IC chip 50 stores various information such as personal identification information and item management information. The second IC chip 50 is also equipped with a predetermined arithmetic processing function and the like, and executes arithmetic processing based on commands contained in a signal input from the second antenna 40, and outputs the processing results to the second antenna 40. The second antenna 40 transmits the signal including the processing results input from the second IC chip 50 to an electromagnetic induction type reader or the like.

[0030] In an IC card 100 equipped with an antenna module 1 having such a configuration, the first antenna 20, which transmits and receives signals by radio wave, is formed in a U-shape in plan view and covers at least 50% or more of the surface area of ​​the substrate 10, making the area of ​​the first antenna 20 as large as possible. This improves the communication performance of the first antenna 20, extends the distance over which wireless communication with a radio wave reader or reader / writer is possible, and enables the reader or the like to read information more appropriately. As a result, a contactless IC card 100 with excellent communication performance can be provided.

[0031] (Variation) The shape of the first antenna 20 shown in FIGS. 2A and 2B is merely an example and is not limited to this shape. FIG. 4 is a plan view (surface view) showing an example of an antenna module 1A having a first antenna 20A of another different shape (variant). The first antenna 20A of the antenna module 1A shown in FIG. 4 has a second slot 25 parallel to a first slot 24 extending in the x-direction. As with the first embodiment, the first antenna 20A of the variant shown in FIG. 4 is provided on a substrate 10 such as a resin film and is a planar antenna for IC cards that is carried by a person or attached to an object for purposes such as access control, logistics management, and product management for facilities. To illustrate the design of this planar antenna, the solid lines indicating parts other than the first antenna 20A, such as the substrate 10 and the second antenna 40 in FIG. 4, can be represented by dashed lines or omitted.

[0032] 4, the area of ​​the first antenna 20A is made as large as possible, thereby improving the communication performance of the first antenna 20A. Furthermore, even if the IC card is placed next to another IC card, the antenna does not affect the communication performance of the first antenna 20A. This increases the distance over which wireless communication between the IC card and a radio wave reader or the like is possible, allowing the reader or the like to more appropriately read information.

[0033] (Second embodiment) Next, an antenna module 1B and a contactless IC card 100 according to a second embodiment of the present disclosure will be described with reference to FIG. 13. FIG. 13 is a plan view (surface view) of the antenna module 1B according to the second embodiment. In the antenna modules 1 and 1A according to the first embodiment and the modified example shown in FIGS. 2A and 4, a first IC chip 30 and a second IC chip 50 are mounted on the first antenna 20, 20A, and the second antenna 40, respectively. In contrast, the antenna module 1B according to the second embodiment shown in FIG. 13 is an antenna module mounted with only one IC chip (third IC chip 60). As with the first embodiment and the modified example, the first antenna 20B according to the second embodiment shown in FIG. 13 is provided on a substrate 10 such as a resin film, and is a planar antenna for an IC card that is carried by a person or attached to an object for purposes such as access control, logistics management, and product management for facilities. In order to show the design of this planar antenna, the first antenna 20B, the solid lines indicating parts other than the first antenna 20B, such as the substrate 10 and the second antenna 40 in Figure 13, can be represented by dashed lines or omitted.

[0034] The configuration of the antenna module 1B shown in Fig. 13 will be described below. This antenna module 1B has a U-shape in plan view, similar to the modified antenna module 1A shown in Fig. 4, and includes a first antenna 20B made of a metal thin film that is provided with first and second slots 24, 25 and disposed on the surface of a substrate 10. Furthermore, this first antenna 20B is disposed on the substrate 10 so as to preferably cover at least 50% or more, and more preferably 60% or more, of one surface of the substrate 10. A third IC chip 60 is mounted at a specified position on this first antenna 20B.

[0035] The antenna module 1B also has a second antenna 40B wound in a coil shape on the other side of the substrate 10. Further, the substrate 10 has through holes 11 and 12 formed therethrough near both ends of the second antenna 40B, and the second antenna 40B and a third IC chip 60 are electrically connected via the through holes 11 and 12 and connection lines 13 and 14. Further, a pair of capacitors 15 for rectifying signals are provided on both side surfaces of the substrate 10, and are electrically connected to the third IC chip 60.

[0036] This third IC chip 60 transmits and receives signals by radio wave using a UHF band frequency (860 to 960 MHz), and also transmits and receives signals by electromagnetic induction using an HF band frequency (13.56 MHz).

[0037] The characteristics of the third IC chip 60 are as follows, but are not limited to these. [Impedance frequency characteristics] 866MHz 19.1-j286Ω 915MHz 17.6-j273Ω [Air Protocol] ISO 15693 and 18000-63

[0038] In the antenna module 1B of the second embodiment and the IC card 100 equipped with the same, the area of ​​the first antenna 20B is made as large as possible, thereby increasing the communication distance of the first antenna 20B and improving communication performance. Furthermore, even if the IC card 100 is stacked with another IC card, the antenna does not affect the communication performance of the first antenna 20B. As a result, the IC card 100 of the second embodiment has a longer distance over which wireless communication with a radio wave reader or reader / writer is possible, and information can be read more appropriately by the reader or the like.

[0039] Furthermore, since the IC card 100 of the second embodiment is equipped with only one third IC chip 60, the IC card 100 can be provided at a lower cost. In addition, the mounting process of mounting the IC chip (third IC chip 60) on the antenna (first antenna 20B) and the converting process of incorporating the antenna module 1B into the IC card 100 can be performed only once, thereby reducing the manufacturing costs of the antenna module 1B and the IC card 100. Furthermore, since the IC cards 100 of the first embodiment and the modified examples are equipped with the first and second IC chips 30 and 50, when writing information such as identification information to these chips using a writing device, writing must be performed twice per IC card 100. In contrast, the IC card 100 of the second embodiment requires writing to the third IC chip 60 only once per IC card 100, thereby improving writing efficiency and more appropriately suppressing writing errors.

[0040] As described above, the antenna modules 1, 1A, 1B of the first embodiment, modified example, and second embodiment of the present disclosure and the contactless IC card 100 equipped with them can improve communication performance, and can extend the communication distance particularly when transmitting and receiving signals using a radio wave method, and can maintain excellent communication performance even when used in conjunction with a transportation IC card or the like.

[0041] As a result, the information on the IC card can be properly read by simply passing near the reader, without having to perform a reading operation such as placing the IC card over the reader or holding it over the reader. Therefore, for example, by carrying the IC card 100 of the above embodiment, even wheelchair users, elderly people, physically disabled people, etc. can have the reader properly read information with high sensitivity by simply passing near the reader, without having to remove the IC card or perform a reading operation. This allows elderly people, etc., to smoothly enter and exit facilities, hospitals, etc., and to automatically check in. Furthermore, when used as a transportation IC card, elderly people, etc., can smoothly board and disembark trains and buses. Furthermore, within a factory or workplace, the system can easily grasp the presence and movement of employees, etc.

[0042] Furthermore, each of the above-described embodiments and modifications includes a first antenna 20, 20A, 20B that transmits and receives signals using radio waves, as well as a second antenna 40, 40B that transmits and receives signals using electromagnetic induction. Therefore, the IC card 100 can transmit and receive signals using both UHF and HF frequencies. For example, HF frequencies can be used for security management, such as controlling the entry and exit of a factory, while UHF frequencies can be used to track the presence and movement of employees. Furthermore, even if the IC card 100 is accidentally left behind, it can be easily found by using UHF frequencies.

[0043] The IC card 100 of each of the above embodiments and modifications can be used as an ID card for public facilities, a patient registration card for hospitals, etc. Installing a reader for this IC card 100 at the entrance, exit, or reception of a public facility or hospital allows wheelchair users, the elderly, the physically disabled, etc. to automatically enter or check in for medical examinations without the need for a reading operation, and allows staff at the public facility, etc. to easily and appropriately manage entry and exit. Even if the IC card 100 is placed in a pass case together with a transportation IC card, the reader can appropriately read the information on the IC card 100. The IC card 100 of each of the above embodiments and modifications can also be used as an IC card for managing boarding and disembarking on public transportation. In this case, the reader can appropriately read the information on the IC card 100 even if the IC card 100 is placed in a pass case together with other transportation IC cards, etc. [Example]

[0044] Next, examples of the present disclosure will be specifically described. The inventors fabricated antenna modules and IC cards according to Examples 1 to 3 and Comparative Example 1 as follows, and verified their communication performance in the UHF band.

[0045] [Example 1] The antenna module 1 and IC card 100 of Example 1 were fabricated with a configuration similar to that of the first embodiment shown in Figures 2A to 3. The antenna module 1 was fabricated by dry laminating a 10-µm-thick aluminum sheet onto a 38 µm-thick PET film 85.6 mm long in the x direction, 54.0 mm long in the y direction, and providing a first antenna 20. A coil-shaped second antenna 40 was provided between the second regions 22 and 23 of the first antenna 20, and first and second IC chips 30 and 50 were mounted at predetermined positions on the first and second antennas 20 and 40. As shown in Figure 3, the first antenna 20 had a length of 75.5 mm in the x direction and a length of 43.50 mm in the y direction. The length of the first slot 24 in the x direction was 34.0 mm. The distance between the second regions 22 and 23 in the x direction was 40.5 mm. The length of the second regions 22 and 23 in the x direction was 17.5 mm. The dimension (diameter) of the second antenna 40 was set to 20.0 mm.

[0046] The first IC chip 30 uses UCODE8 (UCODE is a registered trademark) manufactured by NXP. This first IC chip 30 transmits and receives signals by radio wave method using a UHF band frequency (920 MHz). The second IC chip 50 uses NTAG213 (NTAG is a registered trademark) manufactured by NXP. The second IC chip 50 transmits and receives signals by electromagnetic induction method using a HF band frequency (13.56 MHz). The characteristics of the first IC chip 30 and the second IC chip 50 are as described in the description of the first embodiment above. In Example 2 and Comparative Example 1 described below, the same products as those in Example 1 were used as the first and second IC chips 30 and 50.

[0047] The antenna module 1 fabricated as described above was sandwiched between a pair of cover sheets 2 and 3 formed from PVC plates each having a length of 85.6 mm in the x direction and a length of 54.0 mm in the y direction, and the sheets were then bonded together to fabricate an IC card 100 of Example 1. The communication performance of such an IC card 100 was measured in an anechoic chamber using an RFID tag performance inspection device (Tagformance Pro, manufactured by Voyantic) when the IC card 100 was used alone, when inserted into a pass case, and when inserted into the pass case together with a transportation IC card. The measurement frequency band of the radio wave for wireless communication during measurement was 700 to 1,200 MHz, and the EIRP (Equivalent Isotropically Radiated Power) was 3.28 W.

[0048] Furthermore, for the IC card 100 of Example 1, the change in RSSI (Received Signal Strength Indicator) and the sensitivity difference due to distance were measured using a reader (Impinj Speedway, manufactured by Impinj). This measurement was carried out in the applicant's office, assuming normal use. This reader uses a TIMES-7 A5020 (circularly polarized) antenna, with an output of 20 dBm. Furthermore, the distance from the reader antenna to the IC card when the sensitivity difference was measured was 20 cm.

[0049] [Example 2] Except for the fact that the shape of the first antenna 20 was the same as that of the first antenna 20A of the modified example shown in Figures 4 and 5, the antenna module 1A and the IC card 100 were fabricated in the same manner as in Example 1, and the communication performance, RSSI change, and sensitivity difference were measured in the same manner as in Example 1. In Example 2, the length of the second slot 25 in the x direction was set to 20.5 mm.

[0050] [Comparative Example 1] An antenna module 1' of Comparative Example 1 was fabricated by setting the shape of the first antenna 20' as shown in FIG. 6 and the dimensions of each element as shown in FIG. 7, and an IC card of Comparative Example 1 was fabricated using this antenna module 1'. In Comparative Example 1, the length of the first antenna 20' in the y direction is shorter than half the length of the substrate 10 in the y direction, and the surface area of ​​the metal thin film is less than half (less than 50%) of the surface area of ​​the substrate 10. In addition, the second antenna 40 is not sandwiched between the first antennas 20' but is provided adjacent to the first antennas 20'. For this IC card of Comparative Example 1, the communication performance, RSSI change, and sensitivity difference were measured in the same manner as in Example 1.

[0051] The following describes the measurement results of the communication performance, RSSI change, and sensitivity difference in Example 1, Example 2, and Comparative Example 1. Figures 8 and 9 are diagrams showing the communication performance of IC cards 100 in Example 1 and Example 2 at UHF band frequencies. The thin lines in the graphs in Figures 8 and 9 indicate the communication performance when IC card 100 communicates alone, the medium lines indicate the communication performance when IC card 100 is inserted into a pass case and communicates, and the thick lines indicate the communication performance when IC card 100 and a transportation IC card are placed on top of each other and inserted into the pass case and communicate. The horizontal axis of Figures 8 and 9 represents the frequency of the radio wave for wireless communication, and the vertical axis represents the communicable distance from IC card 100 to a reader (theoretical read range forward).

[0052] FIG. 10 is a diagram showing the communication performance of the IC card of Comparative Example 1 at UHF band frequencies. The thin line in the graph in FIG. 10 indicates the communication performance when the IC card of Comparative Example 1 communicates alone. The medium line in the graph in FIG. 10 indicates the communication performance when the IC card of Comparative Example 1 is inserted into a pass case and communication is performed. The thick dashed line in the graph in FIG. 10 indicates the communication performance when the IC card of Comparative Example 1 is inserted into a pass case and sandwiched between credit cards with an IC chip. The thick line in the graph in FIG. 10 indicates the communication performance when the IC card of Comparative Example 1 is inserted into a pass case and sandwiched between a credit card with an IC chip and a transportation IC card. In FIG. 10, the horizontal axis also represents the frequency of the radio waves for wireless communication, and the vertical axis represents the communicable distance from the IC card of Comparative Example 1 to the reader.

[0053] As shown in Figure 8, with the IC card 100 of Example 1, the communication distance at a predetermined frequency of 920 MHz included in the UHF band was approximately 11 m when alone, approximately 10 m when placed in a pass case, and approximately 9 m when placed in a pass case together with a transportation IC card, showing almost no decrease in the communication distance and excellent communication performance in all cases.

[0054] As shown in Figure 9, the communication distance of the IC card 100 of Example 2 at a predetermined frequency of 920 MHz included in the UHF band was approximately 7 m when the card was used alone, when it was placed in a pass case, or when it was placed in a pass case together with a transportation IC card, meaning that there was almost no reduction in the communication distance and excellent communication performance was demonstrated in all cases.

[0055] On the other hand, as shown in Figure 10, the communication distance for the IC card of Comparative Example 1 was approximately 12 m when it was alone, approximately 12.5 m when it was placed in a pass case, and approximately 13 m when it was sandwiched between credit cards and placed in the pass case. In contrast, when the IC card of Comparative Example 1 was sandwiched between a credit card and a transportation IC card and placed in the pass case, the communication distance was approximately 5 m, which was a significant decrease in the communication distance. Since the built-in antenna of the credit card is small, it has little effect on the IC card, and it is presumed that this significant decrease in the communication distance is due to the influence of the transportation IC card.

[0056] Fig. 11 is a diagram showing the measurement results of RSSI for the antenna modules of Example 1, Example 2, and Comparative Example 1. In Fig. 11, the horizontal axis represents the distance from the antenna of the fixed card reader to the IC card, and the vertical axis represents RSSI. Fig. 12 is a diagram showing the difference in sensitivity among the antenna modules of Example 1, Example 2, and Comparative Example 1.

[0057] 11, the IC cards 100 of Examples 1 and 2 achieved high communication strength not only when used alone, but also when used in close contact with a transportation IC card, even when the distance from the antenna was long. In contrast, in Comparative Example 1, when used together with a transportation IC card, the strength was significantly reduced compared to when used alone, even when the distance from the antenna was short (specifically, the RSSI was "-55" when the distance from the antenna was 1 cm).

[0058] 12, in Examples 1 and 2, there was almost no difference in the sensitivity of the fixed card reader between when it was used alone and when it was attached closely to a transportation IC card, indicating that excellent communication performance could be obtained. In contrast, in Comparative Example 1, there was a large difference in the sensitivity of the fixed card reader between when it was used alone and when it was attached closely to a transportation IC card.

[0059] The above results demonstrate that excellent communication performance, particularly UHF band communication performance, can be improved by including a substrate 10, a first antenna 20, 20A for transmitting and receiving signals provided on the substrate 10, and a first IC chip 30 electrically connected to the first antenna 20, 20A, as in the antenna modules 1, 1A and IC card 100 of Examples 1 and 2, in which the first antenna 20, 20A is formed of a metal thin film that is U-shaped in plan view and is disposed over at least 50% of the surface of the substrate 10. In particular, it was demonstrated that excellent communication performance can be maintained, with almost no decrease in communication distance or communication sensitivity, even when the IC card 100 is used in a pass case or stacked with a transportation IC card.

[0060] [Example 3] An antenna module 1B and an IC card 100 of Example 3 were fabricated with a configuration similar to that of the second embodiment shown in Figures 13 and 14. The antenna module 1B was fabricated by attaching a 10-µm-thick aluminum sheet by dry lamination to a 38-µm-thick PET film having a length of 85.6 mm in the x direction, a length of 54.0 mm in the y direction, and a thickness of 10 µm, to form a first antenna 20B. A coil-shaped second antenna 40 was provided between second regions 22 and 23 of the first antenna 20B. A third IC chip 60 was mounted at a specified position on the first antenna 20B, and the third IC chip 60 and the second antenna 40B were electrically connected via through holes 11 and 12 and connection lines 13 and 14. 3, the first antenna 20B had a length in the x direction of 75.5 mm and a length in the y direction of 43.50 mm, the length in the x direction of the first slot 24 was 34.0 mm, the length in the x direction of the second slot 25 was 20.5 mm, the distance in the x direction between the second regions 22 and 23 was 40.5 mm, and the length in the x direction of the second regions 22 and 23 was 17.5 mm. The second antenna 40 had a length in the x direction of 31.5 mm and a length in the y direction of 12.5 mm.

[0061] The third IC chip 60 is an EM4425 manufactured by Microelectronics. This third IC chip 60 transmits and receives signals by radio wave using UHF band frequencies (860 to 960 MHz) and by electromagnetic induction using HF band frequencies (13.56 MHz). The characteristics of the third IC chip 60 are as described in the second embodiment.

[0062] The antenna module 1B produced as described above was sandwiched between a pair of cover sheets 2 and 3 formed from PVC plates each having a length of 85.6 mm in the x direction and a length of 54.0 mm in the y direction, and these were then bonded together to produce an IC card 100 of Example 3. As with Example 1, the communication performance, changes in RSSI, and sensitivity differences of such an IC card 100 were measured when the IC card 100 was used alone, when it was inserted into a pass case, and when it was inserted into the pass case together with a transportation IC card. For comparison, the measurement results of Comparative Example 1 above were used.

[0063] The following describes the measurement results of the communication performance, RSSI change, and sensitivity difference of Example 3. Fig. 15 is a diagram showing the communication performance of IC card 100 of Example 3 at UHF band frequencies. The thin line in the graph in Fig. 15 indicates the communication performance when IC card 100 communicates alone, the medium line indicates the communication performance when IC card 100 is inserted into a pass case and communicates, and the thick line indicates the communication performance when IC card 100 and a transportation IC card are placed on top of each other and inserted into the pass case and communicate. The horizontal axis of Fig. 15 represents the frequency of the radio wave for wireless communication, and the vertical axis represents the communicable distance from IC card 100 to a reader (theoretical read range forward).

[0064] As shown in Fig. 15, the communicable distance of the IC card 100 of Example 3 at a predetermined frequency of 920 MHz included in the UHF band was approximately 7 m when it was alone, approximately 6 m when it was placed in a pass case, and approximately 5.5 m when it was placed in the pass case together with a transportation IC card, and the communicable distance was hardly reduced. Even when compared with the IC card of Comparative Example 1 shown in Fig. 10, it was shown that the communicable distance of the IC card 100 of Example 3 was not reduced.

[0065] Fig. 16 is a diagram showing the measurement results of RSSI for the antenna modules of Example 3 and Comparative Example 1. In Fig. 16, the horizontal axis represents the distance from the reader antenna to the IC card, and the vertical axis represents RSSI. Fig. 17 is a diagram showing the difference in sensitivity between the antenna modules of Example 3 and Comparative Example 1.

[0066] As shown in Fig. 16, compared to Comparative Example 1, the IC card 100 of Example 3 achieved high communication strength not only when used alone, but also when the IC card was placed on top of a transportation IC card and at a long distance from the antenna. Also, as shown in Fig. 17, in Example 3, there was almost no difference in reader sensitivity between when the IC card was used alone and when it was placed in close contact with a transportation IC card, demonstrating that excellent communication performance was achieved.

[0067] The antenna module and IC card of the present disclosure have been described above based on the embodiments and examples, but the specific configurations are not limited to these examples. Changes and additions to the design are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims. [Explanation of symbols]

[0068] 1, 1A, 1B: Antenna module 10: Substrate 20, 20B, 20C: First antenna 21:First area 22,23 :Second area 30: First IC chip 40, 40B: Second antenna 50: Second IC chip 60: The third IC chip 100: Contactless IC card

Claims

1. A substrate; a first antenna provided on the substrate for transmitting and receiving signals; a first IC chip electrically connected to the first antenna; the first antenna is made of a metal thin film provided on the surface of the substrate, the first slot being arranged in a U-shape in plan view and extending along one long side of the substrate, and a second slot being parallel to the first slot, and the first antenna is arranged so as to cover at least 50% or more of the surface of the substrate; An antenna module characterized by:

2. a second antenna provided on the substrate for transmitting and receiving signals in a frequency band different from that of the first antenna; a second IC chip electrically connected to the second antenna; the first antenna and the second antenna are provided at positions on the substrate where they do not overlap each other in a plan view, The first antenna is disposed in an area on the surface of the substrate other than an area where the second antenna is provided.

2. The antenna module according to claim 1.

3. A substrate; a first antenna provided on the substrate for transmitting and receiving signals; a second antenna provided on the substrate for transmitting and receiving signals in a frequency band different from that of the first antenna; an IC chip electrically connected to the first antenna and the second antenna, The first antenna is formed of a metal thin film on the surface of the substrate in a region that does not overlap with the second antenna in a plan view, and is provided with a first slot that is arranged in a U-shape in a plan view and that extends along one long side of the substrate, and a second slot that is parallel to the first slot, and is arranged so as to cover at least 50% or more of the surface of the substrate. An antenna module characterized by:

4. The substrate is rectangular, The first antenna has a U-shape in plan view, and includes a first region extending in a strip shape of a predetermined width from one short side of the substrate to the other short side along one long side of the substrate, and a pair of second regions extending in strip shapes of a predetermined width from both sides of the first region along the one and other short sides of the substrate to the other long side.

4. The antenna module according to claim 1, wherein the antenna module is a semiconductor device.

5. The antenna module according to any one of claims 1 to 4 is provided. An IC card characterized by:

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