Wireless authentication device

Abstract

To enable stable wireless communication with a user terminal regardless of its orientation, thereby improving the reliability of the authentication of the user terminal.SOLUTION: A wireless authentication device for authenticating a user terminal includes: a communication unit that has a first power supply point provided along one of two mutually orthogonal axes and a second power supply point provided along the other axis, and receives a polarized signal radiated by the user terminal via the first and second power supply points, respectively; a measurement unit that measures a first received power of a linearly polarized component parallel to one axis in the signal received via the first power supply point, and a second received power of a linearly polarized component parallel to the other axis in the signal received via the second power supply point; and an authentication unit that authenticates the user terminal on the basis of either the sum of the measured first received power and second received power, or a value of either the measured first received power or the measured second received power.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wireless authentication device. [Background technology]

[0002] Patent Document 1 states that "based on an instruction from the direct wave direction identification unit 124, the polarization switching unit 121 switches the polarization plane to be received by the antenna element 111 included in the first antenna unit 11A, i.e., the polarization plane to be received by the first antenna unit 11A" (paragraph 0045). Patent Document 2 states that "using all patch antennas 11 and 12, radio waves of the high frequency signal RF11 that has become horizontally polarized are transmitted or received" (paragraph 0065), and "using all patch antennas 11 and 12, radio waves of the high frequency signal RF11 that has become vertically polarized are transmitted or received" (paragraph 0067). Patent Document 3 states, "Next, the control unit 11 (receiving means 117) receives a response wave in response to the horizontally polarized wave radiated in S23. The control unit 11 (receiving means 117) also receives a response wave in response to the vertically polarized wave radiated in S27. The control unit 11 (receiving means 117) also receives a response wave in response to the circularly polarized wave radiated in S31 (both S33)." (paragraph 0058), and "The control unit 11 measures the strength of the received power of the received response wave. The closer an IC tag is positioned in a direction perpendicular to the antenna 3 of the RFID reader / writer 1 that radiated the radio waves, the stronger the received power of the response wave. The closer an IC tag is positioned to the antenna 3 of the RFID reader / writer 1, the stronger the received power of the response wave." (paragraph 0059). [Prior art document] [Patent documents] [Patent Document 1] JP 2017-40552 [Patent Document 2] WO2019 / 102869 [Patent Document 3] JP 2016-53811 Summary of the Invention

[0003] A first aspect of the present invention provides a wireless authentication device for authenticating a user terminal. The wireless authentication device has a first feed point provided on one of two mutually orthogonal axes and a second feed point provided on the other axis, and includes: a communication unit that receives polarized signals radiated by the user terminal via the first feed point and the second feed point, respectively; a measurement unit that measures a first received power of a linearly polarized component of the signal received via the first feed point that is parallel to the one axis, and a second received power of a linearly polarized component of the signal received via the second feed point that is parallel to the other axis; and an authentication unit that authenticates the user terminal based on the sum of the measured first received power and the second received power, or the value of either the measured first received power or the second received power.

[0004] The wireless authentication device may include a plurality of the communication units spaced apart from one another. In any of the wireless authentication devices, the measurement unit may measure the first received power and the second received power received via each of the plurality of communication units. Any of the wireless authentication devices may further include a location determination unit that determines that the user terminal is located closest to the communication unit among the plurality of communication units that has the largest value.

[0005] In any of the above wireless authentication devices, one of the plurality of communication units may be provided on one side of a door, and one of the plurality of communication units may be provided on the other side of the door. In any of the above wireless authentication devices, the position determination unit may determine that the user carrying the user terminal is located on the side of the door where the communication unit with the largest value is provided.

[0006] Any of the above wireless authentication devices may further include a distance estimation unit that estimates a distance to the user terminal based on the earliest received signal of the polarized signals radiated by the user terminal, the signal received via the first feed point, and the signal received via the second feed point.In any of the above wireless authentication devices, the authentication unit may authenticate the user terminal based on the value and the estimated distance.

[0007] Any of the above wireless authentication devices may include a pair of communication units, one of which is provided on one side of a door and the other of which is provided on the other side of the door. In any of the above wireless authentication devices, the distance estimation unit may estimate the distance from each of the pair of communication units to the user terminal based on the signal received by each of the pair of communication units at the earliest time. In any of the above wireless authentication devices, the measurement unit may measure the first received power and the second received power received via each of the pair of communication units. Any of the above wireless authentication devices may further include a position determination unit that, when the communication unit of the pair of communication units with the largest value is the same as the communication unit corresponding to the shorter of the estimated distances from each of the pair of communication units to the user terminal, determines that the user carrying the user terminal is located on the side of the door on which the communication unit with the largest value for the value is provided.

[0008] A second aspect of the present invention provides an electric lock device comprising any one of the wireless authentication devices described above and a locking / unlocking unit that locks or unlocks a door, and the locking / unlocking unit locks or unlocks the electric lock when the authentication unit successfully authenticates the user terminal.

[0009] A third aspect of the present invention provides a wireless authentication method for authenticating a user terminal, comprising: receiving polarized signals radiated by the user terminal via a first feed point provided on one of two mutually orthogonal axes and a second feed point provided on the other of the two axes; measuring a first received power of a linearly polarized component of the signal received via the first feed point that is parallel to the one axis; and measuring a second received power of a linearly polarized component of the signal received via the second feed point that is parallel to the other axis; and authenticating the user terminal based on either the sum of the measured first received power and the measured second received power, or the value of either the measured first received power or the measured second received power.

[0010] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a wireless authentication device 100 according to one embodiment. [Figure 2] 1 is an example of a block diagram of a wireless authentication device 100 incorporated into an electric lock 25 according to one embodiment. [Figure 3] FIG. 2 is a schematic diagram showing an example of a communication unit 130. [Figure 4] 4 is a side view of antenna 133 of communication unit 130 shown in FIG. 3 as viewed in the direction of arrow A. FIG. [Figure 5] 1 is a flow diagram showing an example of a method in which the wireless authentication device 100 according to an embodiment authenticates the user terminal 30 via wireless communication. [Figure 6] 1 is a diagram showing an example of the paths of a direct wave and a reflected wave that reach a first communication unit 131 and a second communication unit 132 from a user terminal 30, respectively. [Figure 7] 10 is a graph illustrating an example of received voltages of a plurality of signals received from a user terminal 30 at different times. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0013] Fig. 1 is a schematic diagram of a wireless authentication device 100 according to one embodiment. As an example, the wireless authentication device 100 according to this embodiment is incorporated into an electric lock 25 provided on the front door 20 of a residence 15. More specifically, the wireless authentication device 100 is incorporated into the upper electric lock 26 of the electric lock 25, which is made up of an upper electric lock 26 and a lower electric lock 27 that wirelessly communicate with each other. In Fig. 1, the wireless authentication device 100 is schematically shown by a dashed line. The electric lock 25 is an example of an electric lock device.

[0014] In Figure 1, the right side of the page is the outside 16 of the residence 15, and the left side is the inside 17 of the residence 15, with the outside 16 and the inside 17 separated by a door 20. Figure 1 shows mutually perpendicular X, Y, and Z axes, with the left-right direction on the page being the Z-axis direction, the up-down direction on the page being the Y-axis direction, and the depth direction on the page being the X-axis direction. In the following description, the X-axis direction may be referred to as the horizontal direction, and the Y-axis direction may be referred to as the vertical direction.

[0015] The wireless authentication device 100 is a device for authenticating a user terminal 30 by wireless communication. The wireless authentication device 100 according to this embodiment enables stable wireless communication with the user terminal 30 regardless of the posture of the user terminal 30, thereby improving the reliability of authentication of the user terminal 30.

[0016] The wireless authentication device 100 communicates with the user terminal 30 in accordance with a specific short-range wireless communication standard, which has a communication range of, for example, at most several tens of meters. The short-range wireless communication standard may be, for example, a communication standard adopted in well-known keyless entry systems or smart entry systems. As the short-range wireless communication standard, for example, UWB (Ultra-Wide Band), which has high distance measurement accuracy, or RFID (Radio Frequency Identification), which uses electromagnetic induction or radio waves, may be adopted, or for example, Bluetooth (registered trademark) Low Energy or Wi-Fi (registered trademark) may be adopted. The UWB wireless communication standard may use a carrier frequency of, for example, approximately 7.25 GHz to 9 GHz.

[0017] The electric lock 25 equipped with the wireless authentication device 100 according to this embodiment at least locks and unlocks the lock 29 when the wireless authentication device 100 successfully authenticates the user terminal 30 via wireless communication and predetermined conditions are satisfied. The user terminal 30 may be, for example, a smartphone, or an electronic key such as a card key, a non-touch key, or a remote control key. When the wireless authentication device 100 communicates wirelessly with the user terminal 30, the user terminal 30 may be placed in a pocket or bag of the user's clothes, or may be held by the user 12.

[0018] 1 , when a user 12, who is a resident of a residence 15, approaches the door 20 from outside 16 of the residence 15 with the user terminal 30 in his / her shoulder bag 13 and requests the electric lock 25 to unlock the lock 29, the electric lock 25 outputs a signal indicating that the operation has been performed to the wireless authentication device 100, and in response, the wireless authentication device 100 authenticates the user terminal 30 via wireless communication. Furthermore, when the wireless authentication device 100 successfully authenticates the user terminal 30, the electric lock 25 automatically unlocks the lock 29. More specifically, when the electric lock 25 receives a signal from the wireless authentication device 100 indicating that the authentication of the user terminal 30 has been successful, the electric lock 25 transmits a signal instructing the locking / unlocking operation unit 28 of each of the upper electric lock 26 and the lower electric lock 27 to unlock the locks 29, and the locks 29 of the upper electric lock 26 and the lower electric lock 27 are automatically unlocked.

[0019] This allows the user 12 to operate the handle 22 of the door 20 to open the door 20 and enter the inside 17 of the residence 15. When the user 12 exits from the inside 17 of the residence 15 to the outside 16 of the residence 15, the electric lock 25 may automatically unlock the lock 29 in the same way as when the user 12 enters from the outside 16 of the residence 15 to the inside 17 of the residence 15.

[0020] Furthermore, for example, if the user 12, with the user terminal 30 in his / her bag 13, stands at the door 20 outside 16 of the residence 15 and performs an operation to request locking of the lock 29 of the electric lock 25, the electric lock 25 outputs a signal indicating that the operation has been performed to the wireless authentication device 100, and in response, the wireless authentication device 100 authenticates the user terminal 30 via wireless communication. Furthermore, the electric lock 25 automatically locks the lock 29 if the authentication of the user terminal 30 by the wireless authentication device 100 is successful. More specifically, when a signal indicating that the authentication of the user terminal 30 is input from the wireless authentication device 100, the electric lock 25 transmits a signal instructing the locking / unlocking operation units 28 of the upper electric lock 26 and the lower electric lock 27 to lock, causing the locks 29 of the upper electric lock 26 and the lower electric lock 27 to automatically lock.

[0021] This allows the user 12 to lock the electric lock 25. When the user 12 locks the electric lock 25 while facing the door 20 inside 17 of the residence 15, the electric lock 25 may automatically lock the lock 29 in the same way as when the user 12 locks the electric lock 25 while facing the door 20 outside 16 of the residence 15.

[0022] In this way, the wireless authentication device 100 according to this embodiment can stably communicate wirelessly with the user terminal 30 in any position and authenticate the user terminal 30, without requiring the user 12 to operate the user terminal 30 or bring the user terminal 30 close to the short-range wireless communication reader of the electric lock 25. As a result, the wireless authentication device 100 can improve the reliability of authentication of the user terminal 30 and also improve convenience for the user 12.

[0023] The locking / unlocking operation unit 28 and the lock 29 of the electric lock 25 may include any configuration for locking or unlocking the door 20 in a closed state. The locking / unlocking operation unit 28 and the lock 29 of each electric lock 25 may include, for example, a deadbolt, an actuator that drives the deadbolt, a keyhole into which a key is inserted from the outside 16 of the door 20, a thumbturn that is rotated from the inside 17 of the door 20, a cylinder that rotates with the key inserted when the shape of the key matches the internal shape of the keyhole, etc. In addition to automatically locking and unlocking the lock 29, the electric lock 25 may also be locked and unlocked by manually operating the locking / unlocking operation unit 28 by the user 12.

[0024] Fig. 2 is an example block diagram of a wireless authentication device 100 incorporated into an electric lock 25 according to one embodiment. In Fig. 2, the signal flow direction is indicated by an arrow, and the door 20 is indicated by a dashed line. In the following description, the upper electric lock 26 and the lower electric lock 27 will be referred to as the electric lock 25 without distinction, simply for the sake of clarity.

[0025] The electric lock 25 according to this embodiment includes an input unit 110 and a locking / unlocking unit 120 in addition to a wireless authentication device 100, a locking / unlocking operation unit 28, and a lock 29. The wireless authentication device 100 according to this embodiment includes a communication unit 130, a measurement unit 140, a distance estimation unit 170, a position determination unit 180, an authentication unit 190, and a storage unit 195.

[0026] The input unit 110 accepts specific operations by the user 12. The input unit 110 is provided on at least one of the outer surface 16 and the inner surface 17 of the door 20 of the residence 15. In this embodiment, the input unit 110 includes a pair of a first input unit 111 and a second input unit 112 provided on both surfaces of the door 20. The first input unit 111 is provided on the outer surface 16 of the door 20, and the second input unit 112 is provided on the inner surface 17 of the door 20.

[0027] As an example, the first input unit 111 and the second input unit 112 each have an unlock button for unlocking the lock 29 and a lock button for locking the lock 29, separately. In this case, the specific operation includes pressing the lock button and pressing the unlock button. When the first input unit 111 and the second input unit 112 receive a specific operation from the user 12, they each output a signal indicating the specific operation, such as an unlock request signal requesting unlocking or a lock request signal requesting locking, to the locking / unlocking unit 120. In the following description, the first input unit 111 and the second input unit 112 may be collectively referred to as a pair of input units 110 or simply as the input unit 110.

[0028] The locking / unlocking unit 120 locks and unlocks the lock 29. More specifically, when a signal indicating a specific operation by the user 12 is input from the input unit 110, the locking / unlocking unit 120 outputs a signal to the communication unit 130 of the wireless authentication device 100 instructing the communication unit 130 to start wireless communication with the user terminal 30 carried by the user 12. When a predetermined condition is subsequently satisfied, the locking / unlocking unit 120 outputs an unlock instruction signal to automatically unlock the lock 29 or a lock instruction signal to automatically lock the lock 29 to the locking / unlocking operation unit 28. As will be described in detail later, in this embodiment, the locking / unlocking unit 120 determines whether the predetermined condition is satisfied based on signals input from the input unit 110 and the position determination unit 180 and authentication unit 190 of the wireless authentication device 100.

[0029] The communication unit 130 transmits and receives signals via wireless communication with the user terminal 30. In this embodiment, the communication unit 130 has a pair of a first communication unit 131 and a second communication unit 132 that are spaced apart from each other. The first communication unit 131 is provided on the outer side 16, which is one side of the door 20, and the second communication unit 132 is provided on the inner side 17, which is the other side of the door 20.

[0030] When a signal instructing the start of wireless communication is input from the locking / unlocking unit 120 of the electric lock 25, the pair of first and second communication units 131 and 132 each starts wireless communication at a specific frequency, for example, UWB wireless communication, with the user terminal 30 carried by the user 12. When a response signal is received from the user terminal 30, the pair of first and second communication units 131 and 132 each outputs the received response signal to the measurement unit 140 and the distance estimation unit 170. Note that the pair of first and second communication units 131 and 132 each have an antenna 133 and a wireless circuit 139, and perform these processes via the antenna 133 and the wireless circuit 139. Note that, as will be described in detail later, the pair of first and second communication units 131 and 132 each independently transmits a response request signal of orthogonal dual polarization that is orthogonal to each other to the user terminal 30 and receives a response signal of orthogonal dual polarization that is orthogonal to each other from the user terminal 30. The response request signal is a signal that requests a response from the user terminal 30, i.e., requests the transmission of a response signal. In the following description, a response request signal of orthogonal dual polarization that is orthogonal to each other may be simply referred to as a polarized response request signal or simply as a response request signal, and a response signal of orthogonal dual polarization that is orthogonal to each other may be simply referred to as a polarized signal or simply as a signal. In the following description, the first communication unit 131 and the second communication unit 132 may be collectively referred to as a pair of communication units 130 or simply as communication unit 130.

[0031] The measurement unit 140 measures the received power of a signal received from the user terminal 30 via the communication unit 130. In this embodiment, the measurement unit 140 separately measures the received power of a signal received from the user terminal 30 via each of the pair of communication units 130. The measurement unit 140 outputs a signal indicating the value of the measured received power for each of the pair of communication units 130 to the position determination unit 180 and the authentication unit 190. Note that, as will be described in detail later, the measurement unit 140 measures a first received power of one linearly polarized component and a second received power of the other linearly polarized component in an orthogonal dual polarized signal received from the user terminal 30 via each of the pair of communication units 130.

[0032] The distance estimation unit 170 estimates the distance to the user terminal 30 for each of the pair of communication units 130 based on the signal received earliest among the multiple polarized signals emitted by the user terminal 30. In this embodiment, the distance estimation unit 170 estimates the distance from each communication unit 130 to the user terminal 30 based on the time it takes for the signal received earliest to be emitted from the user terminal 30 and reach each communication unit 130. The distance estimation unit 170 outputs signals indicating the estimated distance from each of the pair of communication units 130 to the user terminal 30 to the position determination unit 180 and the authentication unit 190. Note that, as will be described in detail later, of the multiple signals received by each communication unit 130 at different times, the signal received earliest can be considered to be a direct wave that has traveled straight from the user terminal 30 to each communication unit 130 without being reflected by a wall, floor, ceiling, etc.

[0033] The position determination unit 180 determines that the user terminal 30 is located closest to the communication unit 130 for which the measured received power values ​​for each of the communication units 130 are the largest, i.e., the largest. As described in detail below, the position determination unit 180 determines that the user terminal 30 is located closest to the communication unit 130 for which the measured received power values ​​for the first and second received powers are the largest. The value for the sum may include a total or an average. In this embodiment, the value for the sum is described as the total. In this embodiment, the position determination unit 180 determines that the user 12 carrying the user terminal 30 is located on the side of the door 20 where the communication unit 130 with the largest measured received power value is provided. The position determination unit 180 outputs a signal indicating the determined position of the user terminal 30 to the locking / unlocking unit 120 of the electric lock 25.

[0034] The authentication unit 190 authenticates the user terminal 30 based on the value related to the received power measured by the measurement unit 140. More specifically, the authentication unit 190 determines that authentication of the user terminal 30 has been successful if the value satisfies a predetermined condition. As an example, the authentication unit 190 estimates the distance to the user terminal 30 from the value, and if the distance is within a predetermined distance range from the wireless authentication device 100, determines that the user terminal 30 is located within the distance range. In this way, as an example, the authentication unit 190 may estimate the distance to the user terminal 30 separately from the distance estimation unit 170 using a method different from the distance estimation method used by the distance estimation unit 170. The authentication unit 190 of this embodiment authenticates the user terminal 30 based on the value and the distance to the user terminal 30 estimated by the distance estimation unit 170, as will be described in detail later. In the following description, the predetermined distance range may be referred to as an authentication distance range.

[0035] The storage unit 195 stores at least one registered ID, which is a unique identification number assigned to each user terminal 30, i.e., the ID of the user terminal 30. In this embodiment, the at least one registered ID is, for example, the ID of one or more user terminals 30 owned by one or more users 12 who are residents of the residence 15. In addition to the registered ID, the storage unit 195 may also store, for example, a function that the distance estimation unit 170 uses the earliest signal to estimate the distance from each communication unit 130 to the user terminal 30, a function that the authentication unit 190 uses a value related to received power to estimate the distance from each communication unit 130 to the user terminal 30, and the numerical value of the above-mentioned authentication distance range, and the like, and the stored data may be read out by the authentication unit 190, the distance estimation unit 170, etc.

[0036] Fig. 3 is a schematic diagram showing an example of the communication unit 130. Fig. 4 is a side view of the antenna 133 of the communication unit 130 shown in Fig. 3, as viewed from the direction of arrow A. The communication unit 130 according to this embodiment includes the antenna 133 and the radio circuit 139, as described above.

[0037] Antenna 133 is a patch antenna having a plane parallel to the XY plane and a rectangular outline in plan view. For example, antenna 133 has equal dimensions in the X-axis direction and the Y-axis direction. The patch antenna may also be referred to as a microstrip antenna, a microstrip patch antenna, or the like. In FIG. 3, the X-axis and Y-axis, which form two mutually orthogonal centerlines of antenna 133 in the XY plane, are indicated by bold lines.

[0038] Antenna 133 has input and output ports for orthogonal dual polarization. More specifically, antenna 133 has a first feed point 135 provided on one of two axes that are orthogonal to each other, and a second feed point 136 provided on the other axis. In this embodiment, first feed point 135 is provided on the X-axis, and second feed point 136 is provided on the Y-axis that is orthogonal to the X-axis. That is, first feed point 135 acts as an antenna feed point for linearly polarized waves having an electric field component in the X-axis direction, and second feed point 136 acts as an antenna feed point for linearly polarized waves having an electric field component in the Y-axis direction.

[0039] In this embodiment, for example, the X-axis direction and the Y-axis direction are the horizontal direction and the vertical direction, respectively. In this embodiment, the first feed point 135 acts as an antenna feed point for horizontally polarized waves, and the second feed point 136 acts as an antenna feed point for vertically polarized waves.

[0040] More specifically, antenna 133 has an antenna element 134, a board unit 137, and a strip conductor 138. Note that in Figures 3 and 4, the internal structure of board unit 137 that cannot be seen from the outside is shown by dashed lines. In Figure 3, strip conductor 138 is also shown by dashed lines.

[0041] Antenna element 134 is disposed on one plane of substrate unit 137. Antenna element 134 is a substantially rectangular conductive thin film pattern formed using a conductive metal material such as copper or silver. Antenna element 134 has a length dimension of, for example, several hundred μm to several mm in the X-axis direction, and a length dimension of, for example, several hundred μm to several mm in the Y-axis direction.

[0042] The length dimension of antenna element 134 in the X-axis direction and the length dimension of antenna element 134 in the Y-axis direction are both set to values ​​that are half the wavelength in electrical length of the high-frequency signal radiated from antenna 133. In other words, antenna element 134 is formed in a substantially square shape with the length of one side being the half wavelength.

[0043] The first feed point 135 described above is formed in the middle of the antenna element 134 in the X-axis direction, offset from the center. The first feed point 135 is electrically connected to a strip conductor 138 extending in the X-axis direction through a via hole indicated by a dashed line in FIGS. 3 and 4. When power is fed from the radio circuit 139 to the first feed point 135 through the strip conductor 138, a current flows in the X-axis direction in the antenna element 134, and the radio wave is radiated as a radio wave having a polarization component in the X-axis direction, i.e., a horizontally polarized wave. When the antenna element 134 receives a polarization component in the X-axis direction, i.e., a horizontally polarized wave, an electrical signal flows from the first feed point 135 to the radio circuit 139 through the strip conductor 138.

[0044] Similarly, the antenna element 134 has the above-mentioned second feed point 136 formed at a midpoint in the Y-axis direction that is offset from the center. Similar to the first feed point 135, the second feed point 136 is electrically connected to a strip conductor 138 extending in the Y-axis direction through a via hole indicated by a dashed line in FIGS. 3 and 4. A current flows in the Y-axis direction in the antenna element 134 when power is fed from the radio circuit 139 to the second feed point 136 through the strip conductor 138. When the antenna element 134 receives a polarized wave component in the Y-axis direction, i.e., a vertically polarized wave component, an electrical signal flows from the second feed point 136 to the radio circuit 139 through the strip conductor 138.

[0045] Note that first feeding point 135 may be shifted to one side in the X-axis direction or to the other side in the X-axis direction from the center of antenna element 134. Similarly, second feeding point 136 may be shifted to one side in the Y-axis direction or to the other side in the Y-axis direction from the center of antenna element 134.

[0046] Substrate unit 137 forms the outer shape of antenna 133, i.e., it has a plane parallel to the XY plane and has a rectangular outline in a plan view. Substrate unit 137 is a multilayer dielectric substrate. More specifically, as shown in FIG. 4, substrate unit 137 has insulating layer 137A, insulating layer 137B, and ground layer 137C, which are stacked in this order.

[0047] Insulating layer 137A and insulating layer 137B are formed of an insulating material, such as a ceramic material or a resin material. Antenna element 134 is laminated on the exposed surface of insulating layer 137A. Ground layer 137C is a thin metal film provided between insulating layer 137A and insulating layer 137B, and is formed of a conductive metal material such as copper or silver, similar to antenna element 134. Ground layer 137C is connected to ground.

[0048] Vias are formed through the insulating layer 137A, the insulating layer 137B, and the ground layer 137C, extending from the strip conductor 138 extending in the X-axis direction to the first feed point 135. Vias are also formed through the insulating layer 137A, the insulating layer 137B, and the ground layer 137C, extending from the strip conductor 138 extending in the Y-axis direction to the second feed point 136. These vias are formed as columnar conductors by, for example, providing a conductive metal material such as copper or silver in a through hole with an inner diameter of approximately several tens to several hundreds of μm. Note that these vias extend through an opening provided in the ground layer 137C without making contact with the ground layer 137C. Therefore, the ground layer 137C faces the antenna element 134, while being insulated from the antenna element 134, with the insulating layer 137A interposed therebetween.

[0049] The strip conductor 138 is formed of a conductive metal material such as copper or silver, similar to the antenna element 134 and the ground layer 137C. The strip conductor 138 is formed in a long, narrow strip shape on the plane opposite to the plane on which the antenna element 134 is provided in the substrate unit 137, i.e., on the exposed surface of the insulating layer 137B. One end of the strip conductor 138 is electrically connected to the above-mentioned via, and the other end is electrically connected to the radio circuit 139.

[0050] Radio circuit 139 may be mounted, for example, on a flat surface on the insulating layer 137B side of substrate unit 137. Radio circuit 139 is electrically connected to strip conductor 138 via two input / output terminals indicated by open circles in FIG. 3, and is thereby electrically connected to first feed point 135 and second feed point 136 of antenna 133.

[0051] Radio circuit 139 supplies a baseband signal to antenna 133. The baseband signal is converted into a high-frequency signal in antenna 133. The high-frequency signal supplied to first feed point 135 becomes a radio wave having a polarization component in the X-axis direction, i.e., a horizontally polarized wave, and is radiated from antenna element 134. The high-frequency signal supplied to second feed point 136 becomes a radio wave having a polarization component in the Y-axis direction, i.e., a vertically polarized wave, and is radiated from antenna element 134.

[0052] More specifically, the radio circuit 139 generates a baseband signal corresponding to a response request signal to be transmitted to the user terminal 30, performs transmission processing such as encoding and modulation on the baseband signal, and supplies the baseband signal to the antenna 133. The baseband signal after transmission processing is converted by the antenna 133 into radio waves in the frequency band used for communication with the user terminal 30, i.e., the above-mentioned high-frequency signal, and is radiated into space as horizontally polarized waves and vertically polarized waves via the first feeding point 135 and the second feeding point 136.

[0053] The high-frequency signal in that frequency band radiated from the user terminal 30, i.e., the polarized wave of the response signal, arrives at the antenna 133. In the antenna 133, of the high-frequency signal from the user terminal 30, the horizontally polarized component is received at the first feeding point 135 and supplied to the radio circuit 139, and the vertically polarized component is received at the second feeding point 136 and supplied to the radio circuit 139. The radio circuit 139 performs reception processing such as decoding and demodulation on the high-frequency signal.

[0054] The communication unit 130 having the configuration described above with reference to FIGS. 3 and 4 can separately emit two mutually orthogonal polarized waves, a horizontally polarized wave in the X-axis direction and a vertically polarized wave in the Y-axis direction, and can separately receive the horizontally polarized and vertically polarized components of a high-frequency signal. In other words, the antenna 133 of the communication unit 130 constitutes a dual-polarized antenna capable of emitting two orthogonal polarized waves, e.g., a horizontally polarized wave and a vertically polarized wave, and receiving orthogonal polarized components, e.g., a horizontally polarized and a vertically polarized component. The communication unit 130 can also be considered a compact polarization diversity radio device that can achieve the functions of two antennas, one for horizontal polarization and one for vertical polarization, in the space of a single element. The communication unit 130 may also include a high-frequency filter for removing frequency components outside a specified band from the polarized waves of a response signal received from the user terminal 30, a low-noise amplifier for amplifying the signal, a frequency converter for converting from a carrier frequency band to an intermediate frequency band, and the like.

[0055] Fig. 5 is a flow diagram showing an example of a method by which the wireless authentication device 100 according to one embodiment wirelessly authenticates the user terminal 30. For example, the flow in Fig. 5 may start when the wireless authentication device 100 incorporated in the electric lock 25 provided on the door 20 of the residence 15 is powered on.

[0056] The electric lock 25 waits until one of the pair of first and second input units 111 and 112 provided on either side of the door 20 receives an unlocking operation (step S101: NO). In response to any of the input units 110 receiving an unlocking operation (step S101: YES), the electric lock 25 transmits a response request signal to the user terminal 30 via each communication unit 130 of the wireless authentication device 100.

[0057] More specifically, when an unlock request signal is input from the input unit 110 that has accepted an operation by the user 12, the locking / unlocking unit 120 of the electric lock 25 outputs a signal to each of the first communication unit 131 and the second communication unit 132 of the wireless authentication device 100 to instruct the start of wireless communication with the user terminal 30 carried by the user 12. The first communication unit 131 and the second communication unit 132 that have received the signal each generate a response request signal, convert the response request signal into radio waves in the frequency band used for communication with the user terminal 30, and radiate the response request signal into space as horizontally polarized waves and vertically polarized waves from the first feeding point 135 and the second feeding point 136, respectively.

[0058] The wireless authentication device 100 judges whether or not each communication unit 130 has received a response signal from the user terminal 30 (step S105). As an example, if the wireless authentication device 100 does not receive a response signal within a predetermined time period after transmitting a response request signal via each communication unit 130 (step S105: NO), it determines that an authentication error has occurred, and notifies the user 12 of the authentication error by emitting sound, light, or the like from the input unit 110 that accepted the unlocking operation in step S101 (step S106), and ends the flow.

[0059] If each communication unit 130 receives a response signal from the user terminal 30 in step S105 (step S105: YES), the wireless authentication device 100 measures the received power of the signal received by each communication unit 130 (step S107).

[0060] 3 and 4, each communication unit 130 is configured to receive the polarized signal radiated by the user terminal 30 via the first feed point 135 and the second feed point 136, respectively. In this embodiment, each communication unit 130 is configured to simultaneously receive the polarized signal radiated by the user terminal 30 via the first feed point 135 and the second feed point 136, respectively. Alternatively, each communication unit 130 may be configured to alternately receive the polarized signal radiated by the user terminal 30 via the first feed point 135 and the second feed point 136, respectively.

[0061] Here, the polarized wave radiated by the user terminal 30 is, for example, a linearly polarized wave. In response to receiving a response request signal, the user terminal 30 radiates a linearly polarized wave of a response signal. For example, the user terminal 30 generates a baseband signal corresponding to a signal to be transmitted to the wireless authentication device 100, and performs transmission processing such as encoding and modulation on the baseband signal. The user terminal 30 converts the baseband signal after transmission processing into a high-frequency signal in a frequency band used for wireless communication with the wireless authentication device 100, and radiates the signal into space as a linearly polarized wave. Note that the polarization plane of the linearly polarized wave transmitted by the user terminal 30 is indefinite because it changes depending on the attitude of the user terminal 30.

[0062] Regarding step S107, specifically, the measurement unit 140 of the wireless authentication device 100 measures a first received power of a linearly polarized component parallel to one axis in a signal from the user terminal 30 received via the first feed point 135, and a second received power of a linearly polarized component parallel to the other axis in the signal received via the second feed point 136. More specifically, the measurement unit 140 measures the first received power of the horizontally polarized component received via the first feed point 135 and the second received power of the vertically polarized component received via the second feed point 136. The measurement unit 140 also measures the first received power and the second received power received via the first communication unit 131 and the second communication unit 132, respectively.

[0063] In addition, if in step S105 only one of the first communication unit 131 and the second communication unit 132 receives a signal and the other does not receive a signal, in step S107 the first received power and the second received power for the other communication unit 130 may be regarded as 0.

[0064] The wireless authentication device 100 estimates the distance from each communication unit 130 to the user terminal 30 based on the signal received earliest out of the signals received via the first feed point 135 and the signals received via the second feed point 136 of each communication unit 130 (step S109). In other words, the wireless authentication device 100 estimates the distance from each of the pair of communication units 130 to the user terminal 30 based on the polarized signals radiated by the user terminal 30, the signal received by each of the pair of communication units 130 via the first feed point 135 and the signal received via the second feed point 136, whichever is the earliest. As described above, the signal received earliest out of multiple signals received by each communication unit 130 at different times can be considered to be a direct wave that has traveled straight from the user terminal 30 to each communication unit 130 without being reflected by a wall, floor, ceiling, etc. That is, the signal received at the earliest time may be either a horizontally polarized direct wave signal or a vertically polarized direct wave signal, whichever is the signal received at the earliest time.

[0065] The distance estimation unit 170 may estimate the distance from each communication unit 130 to the user terminal 30 based on the signal received earliest among multiple signals of horizontally polarized components received at multiple times via the first feed point 135, and the signal received earliest among multiple signals of vertically polarized components received at multiple times via the second feed point 136. As an example, the distance estimation unit 170 may estimate the distance from each communication unit 130 to the user terminal 30 based on a signal obtained by adding together the signal received earliest through the first feed point 135 and the signal received earliest through the second feed point 136. In this way, the distance estimation unit 170 can stably estimate the distance to the user terminal 30 regardless of the attitude of the user terminal 30, i.e., regardless of the polarization plane of the linearly polarized wave radiated from the user terminal 30, by using the sum of the direct wave signals received at the earliest time via each of the first feed point 135 and the second feed point 136.

[0066] The wireless authentication device 100 determines whether the communication unit 130 of the pair of communication units 130 having the largest total value of the first received power and the second received power is the same as the communication unit 130 corresponding to the shorter of the estimated distances from each communication unit 130 to the user terminal 30 (step S115). More specifically, the position determination unit 180 of the wireless authentication device 100 may select the communication unit 130 corresponding to the larger value of the total value of the first received power and the second received power measured for the first communication unit 131 and the total value of the first received power and the second received power measured for the second communication unit 132. The communication unit 130 selected by the position determination unit 180 is likely to be closer to the user terminal 30, that is, it is likely that the user terminal 30 is located on the side of the selected communication unit 130 of the pair of communication units 130. By using the total received power measured for each of the first feed point 135 and the second feed point 136, the position determination unit 180 can stably select the communication unit 130 that is closest to the user terminal 30, regardless of the attitude of the user terminal 30, i.e., regardless of the polarization plane of the linearly polarized wave emitted from the user terminal 30.

[0067] The location determination unit 180 may further determine whether the selected communication unit 130 is the same as the communication unit 130 corresponding to the shorter distance to the user terminal 30 estimated for each communication unit 130 in step 109.

[0068] As described above, the wireless authentication device 100 may use an average value instead of the total value of the first received power and the second received power. Furthermore, the wireless authentication device 100 may use either the first received power or the second received power instead of the total value or the average value of the first received power and the second received power. Various processes by the wireless authentication device 100 may be similar regardless of whether the average value, the total value, or either one of these values ​​is used. Therefore, in the following explanation, only the case where the wireless authentication device 100 uses the total value will be explained, and redundant explanations of the case where the average value or either one of these values ​​is used will be omitted.

[0069] If the wireless authentication device 100 determines in step S115 that the communication unit 130 is the same (step S115: YES), it determines that the user 12 carrying the user terminal 30 is located on the side of the door 20 where the communication unit 130 is provided, and proceeds to step S117. If the wireless authentication device 100 determines in step S115 that the communication unit 130 is not the same (step S115: NO), it determines that an authentication error has occurred, and proceeds to step S106.

[0070] The wireless authentication device 100 further determines whether the estimated distance for the communication unit 130 that has been determined to be the same is within the authentication distance range corresponding to that communication unit 130, and whether the ID contained in the separately received signal matches any of the registered IDs stored in the storage unit 195 (step S117).

[0071] In step S117, the authentication unit 190 of the wireless authentication device 100 authenticates the user terminal 30 using the total value of the first received power and the second received power measured by the measurement unit 140. Specifically, for the communication units 130 determined to be the same by the position determination unit 180 in step S115, the authentication unit 190 of the wireless authentication device 100 authenticates the user terminal 30 based on the total value of the first received power and the second received power measured by the measurement unit 140 in step S107 and the distance to the user terminal 30 estimated by the distance estimation unit 170 in step S109. More specifically, if the total value satisfies a predetermined condition and the distance estimated by the distance estimation unit 170 also satisfies a predetermined condition, the authentication unit 190 determines that the user terminal 30 is located within the authentication distance range corresponding to the communication unit 130. As an example, the authentication unit 190 uses the total value to estimate the distance from the communication unit 130 to the user terminal 30, and if both the distance estimated by the authentication unit 190 and the distance from the communication unit 130 to the user terminal 30 estimated by the distance estimation unit 170 are within the authentication distance range corresponding to the communication unit 130, it determines that the user terminal 30 is located within the authentication distance range.

[0072] The authentication unit 190 of this embodiment further determines that the user terminal 30 is located within the authentication distance range, and if the ID of the user terminal 30 included in a signal separately received from the user terminal 30, for example, via Bluetooth (registered trademark) Low Energy, matches one of at least one registered ID stored in the storage unit 195, it determines that authentication of the user terminal 30 has been successful. If authentication of the user terminal 30 has been successful, the authentication unit 190 outputs a signal indicating success of authentication to the locking / unlocking unit 120 of the electric lock 25.

[0073] The electric lock 25 unlocks the lock 29 (step S121) when the input unit 110 on the side where the communication unit 130 determined by the wireless authentication device 100 in step S115 is provided has accepted the unlocking operation, that is, when the input unit 110 is the same as the input unit 110 that accepted the unlocking operation in step S101 (step S119: YES). More specifically, the locking / unlocking unit 120 of the electric lock 25 automatically unlocks the lock 29 when the authentication unit 190 of the wireless authentication device 100 successfully authenticates the user terminal 30 in step S117 and the input unit 110 provided on the surface where the user 12 is located, which is determined by the position determination unit 180 of the wireless authentication device 100 in step S115, of the first input unit 111 and the second input unit 112, has accepted the unlocking operation. After automatically unlocking the lock 29, the electric lock 25 automatically locks the lock 29 when a predetermined condition is satisfied (step S123), and then ends the flow.

[0074] If the electric lock 25 determines in step S119 that the input unit 110 on the side where the communication unit 130 determined by the wireless authentication device 100 in step S115 is located has not accepted the unlocking operation, the electric lock 25 determines that there is a communication error and proceeds to step S106. In this case, it is highly likely that the user 12 who owns the user terminal 30 has unintentionally placed the user terminal 30 within the authentication distance range, for example, while it has been left on a shelf in the entrance of the residence 15, and another user 12 who does not have the user terminal 30 has performed an unlocking request operation from the input unit 110 on the side of the door 20 where the user terminal 30 is not located. The wireless authentication device 100 can prevent such fraudulent authentication by the user 12, and the electric lock 25 can thereby prevent fraudulent unlocking of the lock 29.

[0075] The authentication unit 190 may determine that authentication of the user terminal 30 has been successful on the condition that the distance estimated with respect to the total value of the received power described above is within the authentication distance range and the IDs match. The authentication unit 190 may also add, as an additional condition, that the distance estimated by the distance estimation unit 170 is within the authentication distance range, as described in the flow of Fig. 5, thereby improving the accuracy of determining the position of the user terminal 30, for example, whether it is located outside 16 or inside 17 of door 20.

[0076] Fig. 6 is a diagram showing an example of the paths of direct waves and reflected waves that reach the first communication unit 131 and the second communication unit 132 from the user terminal 30. For clarity of explanation, Fig. 6 does not show the user 12 carrying the user terminal 30. For the same purpose, Fig. 6 shows the door 20 of the residence 15 with a dashed line, and does not show the electric lock 25.

[0077] 6, direct waves reaching the first communication unit 131 and the second communication unit 132 from the user terminal 30 are indicated by thick white arrows, and reflected waves reaching the first communication unit 131 and the second communication unit 132 are indicated by thin white arrows. FIG. 6 shows, as examples of reflected waves, reflected waves that reach each communication unit 130 after being reflected once by the ceiling of the residence 15, and reflected waves that reach each communication unit 130 after being reflected once by the floor. FIG. 6 also shows, as examples of the authentication distance ranges described above, a first authentication distance range 51 set for the first communication unit 131 and a second authentication distance range 52 set for the second communication unit 132 with dashed circles. The authentication distance ranges corresponding to each of the pair of communication units 130 may be spherical spatial ranges centered on each of the pair of communication units 130, as in the example of FIG. 6, and the radii of the spheres defining the ranges of the pair of communication units 130 may be the same or different.

[0078] 1 to 5, the wireless authentication device 100 according to this embodiment measures the received power of signals received via the first feed point 135 and the second feed point 136 for each communication unit 130, and determines that the user terminal 30 is located on the side of the communication unit 130 for which the total value of the received power at the first feed point 135 and the second feed point 136 is larger. As shown in FIG. 6, when the user terminal 30 is located on the outside 16 of the door 20, the total value for the first communication unit 131 provided on the outside 16 of the door 20 is larger than the total value for the second communication unit 132 provided on the inside 17 of the door 20. The wireless authentication device 100 can determine that the user terminal 30 is located on the side of the communication unit 130 for which the total value is larger.

[0079] 1 to 5, the wireless authentication device 100 according to this embodiment selects, for each communication unit 130, the earliest signal among signals received at different times at each of the first feed point 135 and the second feed point 136, as a direct polarization, and can estimate the distance from each communication unit 130 to the user terminal 30 based on the earliest signal. As shown in FIG. 6, when the user terminal 30 is located outside 16 of the door 20, the length of the direct path from the user terminal 30 to the first communication unit 131 is shorter than the length of the direct path from the user terminal 30 to the second communication unit 132. By using the distance estimated from the earliest signal for each communication unit 130, the wireless authentication device 100 can determine that the user terminal 30 is located on the side of the communication unit 130 with the shorter estimated distance.

[0080] FIG. 7 is a graph illustrating an example of the received voltages of multiple signals received from the user terminal 30 at different times. The horizontal axis of the graph in FIG. 7 indicates time [s], and the vertical axis indicates the received voltage [V]. As described above, the wireless authentication device 100 measures the received power measured for the first feed point 135 and the received power measured for the second feed point 136, calculates the sum of these received powers, and uses it for subsequent processing. As an example of measuring the received power and calculating the sum, the wireless authentication device 100 may measure the received voltage measured for the first feed point 135 and the received voltage measured for the second feed point 136, and calculates the sum of these received voltages and uses it for subsequent processing.

[0081] As shown in Fig. 7, the measured value of the received voltage for the first feed point 135 may be smaller than the measured value of the received voltage for the second feed point 136, and vice versa. As shown in Fig. 7, the distance estimation unit 170 and the authentication unit 190 of the wireless authentication device 100 can stably select and authenticate the communication unit 130 based on the total value of the received power for the first feed point 135 and the received power for the second feed point 136. In step S107 of the flowchart in Fig. 5, the measurement unit 140 of the wireless authentication device 100 may determine the result of time integration of the received voltage of the electrical signal from the first feed point 135 as the first received voltage, or may determine the result of time integration of the received voltage of the electrical signal from the second feed point 136 as the second received voltage.

[0082] 7, peaks of the measured value of the received voltage may be detected at different times T1, T2, and T3 at each of the first feed point 135 and the second feed point 136. As an example, the distance estimation unit 170 of the wireless authentication device 100 may perform detection on the high-frequency signal acquired via each of the first feed point 135 and the second feed point 136 of each communication unit 130, and acquire a signal from which the carrier component has been removed from the high-frequency signal. In this way, the distance estimation unit 170 may detect signal peaks at three times, T1, T2, and T3, as shown in FIG. 7, for example.

[0083] The signal peak may be detected by a known method. For example, a peak may be detected when the observed received voltage exceeds a predetermined threshold value relative to the immediately preceding average value per a certain period of time. Alternatively, a peak may be detected when the ratio of the currently observed value to the immediately preceding average value per a certain period of time exceeds a predetermined threshold value. The distance estimation unit 170 may also include a high-frequency filter for removing frequency components outside a specified band from the signal, a low-noise amplifier for amplifying the signal, and the like. Furthermore, the distance estimation unit 170 may also perform processes such as conversion from an analog signal to a digital signal, demodulation, and decoding.

[0084] The distance estimation unit 170 measures the time from when the communication unit 130 emits a response request signal until the signal received from the user terminal 30 at the first time T1, i.e., the earliest signal, is detected. The distance estimation unit 170 may then output a signal indicating the measured time to the authentication unit 190 together with the earliest signal.

[0085] 5, the communication unit 130 may output a signal indicating the time at which the response request signal was transmitted to the user terminal 30 to the distance estimation unit 170, thereby allowing the distance estimation unit 170 to recognize the time at which the response request signal was transmitted from each communication unit 130 to the user terminal 30. In this case, in step 111 of the flow in FIG. 5, the distance estimation unit 170 may select the earliest signal from multiple signals received at different times after that time. In this case, in step S109 of the flow in FIG. 5, the distance estimation unit 170 may estimate the distance from each communication unit 130 to the user terminal 30 based on the time between the two times.

[0086] When the communication unit 130 and the distance estimation unit 170 use a common clock, the communication unit 130 does not need to output to the distance estimation unit 170 a signal indicating that it has transmitted a response request signal to the user terminal 30. In this case, in step S109 of the flow in Fig. 5 , the distance estimation unit 170 may determine the time when the response request signal was transmitted by the communication unit 130 and the time when the earliest signal selected by the distance estimation unit 170 was received by determining in advance that the communication unit 130 will transmit a response request signal a predetermined number of clocks after any of the input units 110 accepts an unlocking operation.

[0087] The time between these two times, i.e., the direct wave time, may include not only the time required for a signal transmitted from the user terminal 30 to reach each communication unit 130, i.e., the return path time, but also the time required for a response request signal transmitted from each communication unit 130 of the wireless authentication device 100 to propagate to the user terminal 30, i.e., the outbound path time, and the time required for the user terminal 30 that received the response request signal to generate and transmit a signal, i.e., the response processing time. Therefore, these components must be taken into consideration when estimating the distance from the direct wave time. The response processing time may be determined in advance, for example, through actual testing or simulation. In other words, the response processing time can be considered a constant value, and by subtracting the response processing time from the direct wave time, the time during which the signal propagates through space can be extracted. Furthermore, the outbound path time may be considered to be the same as the return path time. Therefore, the return path time may be calculated by dividing the time obtained by subtracting the predetermined response processing time from the direct wave time by two. Alternatively, the distance from each communication unit 130 to the user terminal 30 may be calculated by multiplying the return time by the propagation speed of the radio wave.

[0088] The wireless authentication device 100 according to the embodiment described above has a first feed point 135 provided on one of two mutually orthogonal axes, and a second feed point 136 provided on the other axis. Polarized signals radiated by the user terminal 30 are received via the first feed point 135 and the second feed point 136, respectively. The wireless authentication device 100 also measures a first received power of a linearly polarized component of the signal received via the first feed point 135 that is parallel to one axis, and a second received power of a linearly polarized component of the signal received via the second feed point 136 that is parallel to the other axis. The wireless authentication device 100 also authenticates the user terminal 30 based on the sum of the measured first and second received powers. The wireless authentication device 100 having such a configuration enables stable wireless communication with the user terminal 30 regardless of the orientation of the user terminal 30, thereby improving the reliability of authentication of the user terminal 30.

[0089] In the above embodiments, both the antenna of the first communication unit and the antenna of the second communication unit have been described as having a first feed point that serves as an antenna feed point for horizontally polarized waves and a second feed point that serves as an antenna feed point for vertically polarized waves. Alternatively, the antennas of the pair of communication units may have a first feed point provided on one axis that is angled with respect to the horizontal, for example, at an angle of 45 degrees, and a second feed point provided on another axis that is orthogonal to the first axis. Furthermore, the two orthogonal axes of the antennas of the pair of communication units may be the same or different.

[0090] In the above embodiments, the wireless authentication device authenticates the user terminal via wireless communication in response to the input unit accepting a specific operation by the user when the user carrying the user terminal approaches the door and enters the authentication distance range, and the electric lock locks or unlocks the lock when the authentication by the wireless authentication device is successful and predetermined conditions are satisfied. For example, it is assumed that a resident of a house leaves the user terminal within the authentication distance range of the front door, such as on a shelf at the entrance. In this case, the wireless authentication device can prevent the resident from authenticating the left user terminal without realizing it, and thereby the electric lock can prevent the lock from automatically unlocking or leaving it unlocked.

[0091] Alternatively, the wireless authentication device may authenticate the user terminal via wireless communication when the user carrying the user terminal simply approaches the door and enters the authentication distance range. The electric lock may automatically unlock the lock if authentication by the wireless authentication device is successful, and automatically lock the lock when the user simply moves away from the door and leaves the authentication distance range. The wireless authentication device and electric lock may be configured so that the user can enable or disable the function that operates in this way. When the function is disabled, the wireless authentication device and electric lock may authenticate the user terminal via wireless communication when the input unit accepts a specific operation by the user or receives a specific signal from the user terminal when the user carrying the user terminal approaches the door and enters the authentication distance range, and may lock or unlock the lock if authentication is successful. Alternatively, the electric lock may not have an input unit. In this case, the authentication distance range of the wireless authentication device may be set narrower to prevent, for example, the above-mentioned case where an unattended user terminal is authenticated and the lock is automatically unlocked or left unlocked.

[0092] In the above embodiments, the electric lock may have only an unlock button as the input unit instead of having a separate lock button and an unlock button. In this case, the electric lock may automatically lock the lock when a predetermined time has elapsed since the lock was unlocked. In this case, when a user operates a lock / unlock operation unit on the inside of the door, such as a thumb turn, to unlock the lock, the electric lock may not automatically lock the lock even when a predetermined time has elapsed since the lock was unlocked, but may lock the lock when the input unit receives the user's lock operation and makes the above-mentioned various determinations. For example, it is assumed that a resident of the house leaves the house for a short time without carrying a user terminal to take out the trash or to greet visitors outside the front door. The wireless authentication device and the electric lock function in this way to prevent the resident from being unintentionally locked out of the house.

[0093] In the above embodiments, the wireless authentication device has been described as being incorporated into an electric lock on a front door of a residence. Alternatively, the wireless authentication device may be provided at the entrance of an apartment building or office building and configured to lock and unlock an automatic door. The wireless authentication device may be provided at an elevator hall of an apartment building or office building and configured to switch an elevator call button between operable and inoperable.

[0094] In these cases, the wireless authentication device may be provided with an input unit for confirming the user's intention, or may not be provided with an input unit for improving user convenience. The input unit for confirming the intention may be, for example, a human presence sensor with a close-range detection range, such as a hand wave sensor. In this case, the user bringing their hand close to the hand wave sensor is an example of a specific user operation.

[0095] If an input unit is not provided to improve user convenience, for example, to prevent the wireless authentication device from mistakenly authenticating a user terminal carried by a user who is behind the wall at the entrance or elevator hall, or mistakenly authenticating a user terminal carried by a user who is inside the elevator, an additional human presence sensor may be provided whose detection range is limited to in front of the automatic doors at the entrance or in front of the elevator at the elevator hall.

[0096] In the above embodiments, the wireless authentication device communicates wirelessly with the user terminal without the user having to operate the user terminal. Alternatively, the wireless authentication device may be configured so that, after the user performs a locking / unlocking operation on the user terminal and the wireless authentication device receives a signal from the user terminal in response to the locking / unlocking operation, if the user terminal is authenticated, the electric lock locks / unlocks the door in response to the locking / unlocking operation.

[0097] In the above embodiments, the wireless authentication device communicates wirelessly with the user terminal without the user having to bring the user terminal close to the wireless authentication device. Alternatively, the user may bring the user terminal close to a reader of the wireless authentication device, and the wireless authentication device may authenticate the user terminal that is brought within a predetermined distance from the reader. In this case, the reader is an example of a communication unit and an input unit, and bringing the user terminal close to the reader is an example of a specific user operation.

[0098] In the above embodiments, the user terminal may radiate a circularly polarized or elliptically polarized signal instead of a linearly polarized signal. Furthermore, when a linearly polarized signal is radiated by the user terminal, the signal may become elliptically polarized when it reaches the wireless authentication device.

[0099] In the above embodiments, each configuration of the wireless authentication device may use either the first received power or the second received power measured by the measurement unit, instead of using the sum or average of the first received power and the second received power measured by the measurement unit. In this case, for example, the authentication unit of the wireless authentication device may select either one of the first received power and the second received power based on, for example, predetermined criteria. This prevents unnecessary effects on authentication of the user terminal, such as selecting the one that does not satisfy the criteria. Furthermore, because reflected waves are attenuated to a certain extent by reflection from walls and the like, the received power received by the power supply unit and measured by the measurement unit may be weaker than the direct wave. Therefore, for example, if the authentication unit of the wireless authentication device is configured to authenticate the user terminal based on the received power corresponding to the greater received power, the authentication unit can estimate the distance from the communication unit to the user terminal based on the received power corresponding to the direct wave. This prevents the authentication unit from erroneously estimating the distance based on the received power corresponding to the reflected wave, thereby improving the accuracy of distance estimation.

[0100] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0101] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0102] 12 users 13 Bag 15. Housing 16 outside 17 Inside 20 Doors 22 Handle 25 Electric Lock 26 Upper electric lock 27 Lower electric lock 28 Locking / unlocking operation section 29 locks 30 User terminals 51 First authentication distance range 52 Second authentication distance range 100 Wireless authentication device 110 Input section 111 First input section 112 Second input section 120 Locking / unlocking section 130 Communications Department 131 First Communications Department 132 Second Communications Department 133 Antenna 134 antenna elements 135 First feeding point 136 Second feeding point 137 Circuit Board Unit 137A Insulation layer 137B Insulating layer 137C Ground layer 138 Strip Conductor 139 Radio circuit 140 Measuring section 170 Distance estimation unit 180 Position determination section 190 Authentication Department 195 Storage area

Claims

1. A wireless authentication device for authenticating a user terminal, a communication unit having a first feed point provided on one of two mutually orthogonal axes and a second feed point provided on the other axis, the communication unit receiving polarized signals radiated by the user terminal via the first feed point and the second feed point, respectively; a measurement unit that measures a first received power of a linearly polarized component of the signal that is parallel to the one axis and that is received via the first feed point, and a second received power of a linearly polarized component of the signal that is parallel to the other axis and that is received via the second feed point; an authentication unit that authenticates the user terminal based on a value of either the sum of the measured first received power and the measured second received power, or the value of either the measured first received power or the measured second received power; A wireless authentication device comprising:

2. a plurality of the communication units provided at intervals from each other; the measurement unit measures the first received power and the second received power received via each of the plurality of communication units; The user terminal further includes a location determination unit that determines that the user terminal is located closest to the communication unit having the largest value among the plurality of communication units. The wireless authentication device according to claim 1 .

3. One of the plurality of communication units is provided on one side of the door, and one of the plurality of communication units is provided on the other side of the door, the position determination unit determines that the user carrying the user terminal is located on the side of the door on which the communication unit having the largest value is provided, among both sides of the door; The wireless authentication device according to claim 2.

4. a distance estimation unit that estimates a distance to the user terminal based on the earliest received signal of the polarized signal radiated by the user terminal received via the first feed point and the signal received via the second feed point, the authentication unit authenticates the user terminal based on the value and the estimated distance. The wireless authentication device according to claim 1 .

5. a pair of communication units, one of which is provided on one side of the door and the other of which is provided on the other side of the door; the distance estimation unit estimates a distance from each of the pair of communication units to the user terminal based on the signal received by each of the pair of communication units at the earliest time; the measurement unit measures the first received power and the second received power received via each of the pair of communication units, and a position determination unit that, when the communication unit of the pair of communication units with the largest value is the same as the communication unit corresponding to the shorter of the estimated distances from each of the pair of communication units to the user terminal, determines that the user carrying the user terminal is located on the side of the door on which the communication unit with the largest value is provided. The wireless authentication device according to claim 4.

6. The wireless authentication device according to any one of claims 1 to 5, A locking / unlocking unit that locks or unlocks the door; Equipped with the locking / unlocking unit locks or unlocks the lock when the authentication unit has successfully authenticated the user terminal; Electric locking device.

7. A wireless authentication method for authenticating a user terminal, comprising: receiving polarized signals radiated by the user terminal via a first feed point provided on one of two mutually orthogonal axes and a second feed point provided on the other axis; measuring a first received power of a linearly polarized component of the signal received via the first feed point that is parallel to the one axis, and a second received power of a linearly polarized component of the signal received via the second feed point that is parallel to the other axis; authenticating the user terminal based on a value of either the sum of the measured first received power and the measured second received power, or the measured first received power and the measured second received power; A wireless authentication method comprising:

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