General antenna for multi-band 3D

Abstract

To provide a 3D antenna system that has excellent inductance, Q factor, and sensitivity and operates at three or more operating frequencies.SOLUTION: An antenna system according to the present invention includes: a magnetic core surrounded by a multiaxial coil comprised of multiple types of coils 12 wound around each of three orthogonal axes; a support member that insulates and holds the coil 12; and a connection box 10 connected to the external connector 11 of the coil. Each coil 12 of each axis has a specific cross-sectional area and a given number of turns, and each coil includes two external connectors 11. The box 10 provides a reconfigurable interconnect 16 between the box and the external connector 11, so that separate external interconnects of the external connector 11 are established utilizing the connection box 10 to form a plurality of separate antenna coil circuits.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a multi-band three-axis antenna (receiving element). This multi-band three-axis antenna has a core and six winding wires wound around three orthogonal axes of this core. The 3D antenna is for a transponder / transceiver, and is particularly used in the field of automotive smart keys, and is optimized to operate at various frequencies.

Background Art

[0002] Currently, frequency is the first point that determines the selection of 3D coils for PE / PS (Passive Entry / Passive Start) in the automotive field. The three types of frequencies in low-frequency communication used in this field are 125 kHz, 134.2 kHz, and 20 kHz.

[0003] The 3D coil is part of an RFID communication transponder established between an automobile and its user / user's key.

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a 3D coil antenna independent of the frequency adopted by a user in a certain application.

[0005] This means that it is necessary for the device to be as small as possible for the current design to operate in applications with various (different) frequencies and to meet the minimum electrical parameters in mobile applications.

[0006] The challenging matters are the internal and external connections of various windings, the design of the core and windings, and the target external volume.

[0007] The advantage is a single transponder that can operate with chips operating at various frequencies or various chips and is extremely compact and high-performance.

[0008] The problem that the invention attempts to solve is that the chips used in an application limit the selection of transponders thing or limit the connection of chips operating at three types of frequencies. Therefore, what is necessary is to connect the chips to two or three transponders with economic cost taking into account and have space in the hardware of the application to make the connection.

[0009] In addition to this, it is important to take into account the harmonization of the inductance range, Q factor, and sensitivity of the antenna when the antenna operates at various frequencies.

[0010] For PE / PS applications, a three-dimensional antenna having a 3D coil antenna disclosed in Patent Document 1 is necessary as an inductive receiver on the transponder side. As a result, the communication between the transmitter and the receiver (transponder) is independent in the direction within the space of the receiver. However, this 3D coil antenna has only three windings orthogonal in space (each operating optimally at one frequency). Therefore, in order to operate at three types of frequencies in the application, three 3D coils are required, and each of these coils needs to be designed according to the frequency at which it operates in the application.

[0011] Patent Document 2 discloses a transponder having coil antennas overlapping on a common core. In this coil antenna, a plurality of coils exist orthogonally in three main three directions in space. However, in other applications, it is different from applications that receive various frequencies.

[0012] In other known approaches, the use of 3D coils and capacitor modulation have been proposed (Patent Document 3). However, when implementing this, the coil design cannot be optimized at the operating frequency. The only possibility is that the same coil operates at different frequencies.

[0013] What other applications propose is to use another frequency range as high-frequency NFC (Near Field Communication) together with UHF (Ultra High Frequency).

[0014] Patent Document 4 (PREMO) discloses a high-gain three-axis antenna with an increased Q factor for a purpose different from the present invention. The increase in the Q factor is based on a special core around which three orthogonal coils are directly wound, and each of the coils is separated into two coil parts by the partition wall of its own core. This proposed solution contributes to miniaturization and volume reduction.

[0015] Patent Document 5 discloses a multi-purpose antenna device for a remote access system. This antenna device has a package including first, second, third, and fourth coil antennas. The first coil antenna is oriented in the direction of the X plane and is configured to receive a low-frequency (LF) signal having a carrier frequency between 30 kHz and 300 kHz. The second coil antenna is oriented in the direction of the Y plane and is configured to receive a low-frequency (LF) signal having a carrier frequency between 30 kHz and 300 kHz. The third coil antenna is oriented in the direction of the Z plane and is configured to receive a low-frequency (LF) signal having a carrier frequency between 30 kHz and 300 kHz. The fourth coil antenna is oriented in the direction of the Z plane and is configured to transmit a signal having a high-frequency (HF) carrier frequency between 3 MHz and 30 MHz.

Means for Solving the Problems

[0016] In the design of a chip used in a PE / PS (Passive Entry / Passive Start) application in the field of automobiles, compared with other applications of 3D coil designs, it is necessary to maximize several characteristics. Thus, a 125 kHz chip needs to operate with a 3D coil showing high sensitivity S, a 134.2 kHz chip needs to obtain higher performance from the perspective of high quality factor Q in this 3D coil, and a 20 kHz chip needs to operate with a very high inductance L.

[0017] The present invention is a 3D coil that is operable at all three frequencies covering the needs of the application and in which everything is incorporated into a single SMD component. This is very effective for incorporating a vehicle's PE / PS key into a mobile phone and for making this system executable in all current vehicles independently of the mobile phone model (frequency).

[0018] Therefore, in one embodiment, a 3D coil for a "universal chip" operable at any of the frequencies 22 kHz, 125 kHz, and 134.2 kHz is proposed.

[0019] The antenna proposed here is a small antenna. As an example, the dimensions of the antenna in the X-axis and Y-axis directions are 196 mm or less. In a preferred embodiment, it is 14 mm x 14 mm. The thickness of the antenna in the Z-axis direction is 1.65 mm or less.

[0020] The multi-band 3D universal antenna of the present invention with the above dimensions includes a magnetic core, a support member, and a connection box. * The magnetic core is surrounded by a multi-axis coil wound around each of the X-axis, Y-axis, and Z-axis, which are three orthogonal axes. This multi-axis coil includes at least two different (two types of) coils wound around at least one or two of the three orthogonal axes. * The support member holds or insulates the coil. The coil of each axis has a specific cross-sectional area and a predetermined number of turns (of the winding wire), and has two external connectors. * The connection box is connected to the external connectors of each coil and provides a reconfigurable interconnection between the external connectors. As a result, different external interconnections of the external connectors are established by means of the connection box, and a plurality of different (multiple types of) antenna coil circuits are obtained.

[0021] The established separate (multiple) external interconnections are (i) within a predetermined inductance range, (ii) within a predetermined Q-factor range, (iii) within a predetermined sensitivity range and operate at three or more operating frequencies.

[0022] In one embodiment, the multi-axis coil has at least two different (two types of) coils wound around each of the three orthogonal axes, and these at least two types of coils have different cross-sectional areas and numbers of turns.

[0023] That is, the present invention proposes a 6-winding 3D core (6-winding 3DC) having six windings that share the same core (e.g., a ferrite core). Three of the windings operate at frequencies of 125 kHz and 134.2 kHz. The other three windings are connected together and operate at a frequency of 20 kHz. As a result, the final product is an SMD pickup having only eight pins.

[0024] This connection box provides a reconfigurable interconnection according to a predetermined inductance range, quality coefficient Q (also referred to as the "Q coefficient") range, and sensitivity range, and operates within the three operating frequency ranges described above.

[0025] In one embodiment, the multi-band antenna of the present invention is a receiving antenna, and the external connector responds to a predetermined operating frequency radiated in the vicinity.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0027] To solve the above problems, at least, it is necessary to operate at frequencies of 125 kHz and 134.2 kHz three windings and to operate at a frequency of 20 kHz three windings to be made These operating frequencies are within the RFID band.

[0028] The requirements for Q factor and sensitivity are quite different at these three frequencies. The current chips operating at 125 kHz are suitable for coils with Qmin of 15, while the current chips operating at 134 kHz require coils with Qmin of 30. What is required at 20 kHz is a high inductance value that meets the sensitivity needs.

[0029] As a result, for 125 kHz and 134 kHz, the same three coils may be used, but the ultimate goal is to achieve a Qmin of 30.

[0030] Providing separate connections for six coils means that 12 separate connections are required.

[0031] However, the coils on the same axis for 125 kHz and 20 kHz will share the pins that are the end of the 125 kHz coil and the start of the 20 kHz coil, and thus, 9 separate contacts are required.

[0032] In another configuration, the six coils can also share the ground connection. Then 7 different contacts are required.

[0033] The winding method of the coils also has to be determined. At 125 kHz, both the first X-wound wires, the first X-wound wire and the Y-wound wire.

[0034] According to one embodiment, the present invention provides a multi-band 3D general-purpose antenna system including a magnetic core, a support member, and a connection box 10. *The magnetic core is surrounded by a multi-axis coil wound around each of the three orthogonal axes, the X-axis, the Y-axis, and the Z-axis. The multi-axis coil has a plurality of types of coils 12 wound around at least one of the three orthogonal axes. *The support member insulates and holds the coil 12. Each coil of each axis has a predetermined cross-sectional area and a predetermined number of turns, and has two external connectors 11. *The connection box 10 is connected to the external connectors 11 of the coil and provides a reconfigurable interconnect 16 between the external connectors 11. Thereby, a plurality of separate antenna coil circuits are formed.

[0035] According to one embodiment, the coils are spatially dispersed and housed in a small enclosure having a predetermined height, length, and width, and the height of the enclosure is less than or equal to 1 / 2 of the length and 1 / 2 of the width.

[0036] If there is only one winding instead of two windings on a certain axis, the 3D coil can operate in three bands (20, 125, 134.2 kHz) for the axis with two windings and the axis with only one winding.

[0037] Similarly, the present invention also assumes the case where there is only one multi-band axis.

[0038] However, in a preferred embodiment, the multi-axis coil has at least two types of coils 12 wound around each of the three orthogonal axes. Each of the at least two types of coils 12 has a different cross-sectional area and number of turns. In the embodiment shown in FIG. 2, the multi-band (multi-frequency) antenna 1 is housed in the connection box 10.

[0039] According to one embodiment, the connection box 10 is an integrated circuit (IC).

[0040] As described above, the connection box 10 has a reconfigurable interconnect 16 (i) within a predetermined inductance range, (ii) a predetermined Q - factor range, (iii) a predetermined sensitivity range and is provided according to the above, and operates at three or more operating frequencies.

[0041] According to one embodiment, the multi - band 3D general - purpose antenna 1 is a receiving antenna, and the connection box 10 is configured to respond to the operating frequencies radiated from the adjacent area.

[0042] The data of a specific embodiment will be detailed as values to be protected. ● The predetermined inductance range for a frequency of 20 kHz is 20 mH, and the predetermined inductance range for a frequency of 125 kHz or 134.2 kHz is between 2.38 mH and 7.2 mH. ● The Q - factor for a frequency of 20 kHz is 3.5 or more, the Q - factor for a frequency of 125 kHz is 15 or more, and the Q - factor for a frequency of 134.2 kHz is 30 or more. ● The sensitivity for a frequency of 20 kHz is 22 mV / A / m, and the sensitivity for a frequency of 125 kHz or 134.2 kHz is between 70 mV / A / m and 80 mV / A / m.

[0043] In the embodiment shown in FIGS. 3 - 6, six coils 12X1, 12X2, 12Y1, 12Y2, 12Z1, 12Z2 are arranged around the X - axis, Y - axis, and Z - axis. The first set of three coils 12X1, 12Y1, 12Z1 has a cross - sectional area and number of turns such that it operates at a frequency of 125 kHz or 134.2 kHz. The other three coils 12X2, 12Y2, 12Z2 of the second set have a cross - sectional area and number of turns such that they operate at a frequency of 20 kHz. The reconstructable interconnect 16 is related to the interconnection between certain ones of the respective external connectors 11 of each of the six coils. This is done according to the following antenna - coil circuit.

[0044] The first antenna - coil circuit shown in FIG. 3. This circuit provides a common ground 13 to each of the six coils 12X1, 12X2, 12Y1, 12Y2, 12Z1, 12Z2, As a result, seven external connections and is formed by the connection box 10.

[0045] The second antenna coil circuit shown in FIG. 4. This circuit has an intermediate connector 15 between the coils 12X1 and 12X2 on the X-axis, between the coils 12Y1 and 12Y2 on the Y-axis, and between the coils 12Z1 and 12Z2 on the Z-axis. As a result, nine each are formed by the connection box 10. external connection

[0046] The third antenna coil circuit shown in FIG. 5. This circuit provides a common ground 13 to one coil 12X1, 12Y1, 12Z1 of each axis, and has an intermediate connector 15 between the coils 12X1 and 12X2 on the X-axis, between the coils 12Y1 and 12Y2 on the Y-axis, and between the coils 12Z1 and 12Z2 on the Z-axis. As a result, each seven to the interconnect 16 are formed by the connection box 10. external connection

[0047] The fourth antenna coil circuit shown in FIG. 6. This circuit has two common grounds, namely, a common ground 13 on the left shared by the three coils 12X1, 12Y1, 12Z1 on one side of each axis, and a common ground 13 on the right shared by the three coils 12X2, 12Y2, 12Z2 on the other side of each axis. As a result, eight external connection are formed by the connection box 10.

[0048] The various connection configurations described above should not be construed as limiting the scope of the present invention, which reconfigures the interconnection of different coils. The present invention also proposes winding three or more coils around each axis. According to various experiments by the present inventor, for the Q factor, it is preferable to wind in the order of X1 + Y1 + X2 + Y2 + Z1 + Z2.

[0049] By providing a common connection for each pair of winding wires, the number of pins can be reduced from 12 to 9, but the Q factor 15% will decrease. When using a common ground connection for the coils at 20 kHz (L2), the number of pins can be reduced from 9 to 8. ​​

[0050] in Figure 3 As in the embodiment, in the common ground connection, the number of pins can be reduced from 12 to 7, but the Q factor decreases by 25% at X1, and the decrease in sensitivity is 30%.

[0051] Reducing the number of pins to 12 for a better Q factor is an optimal choice for compromise in is to make a common connection for every two winding lines (for 125 kHz to 20 kHz) and make a common ground connection for 20 kHz (L2). This is the sixth sample (antenna coil circuit) referred to as 。

[0052] These results are based on samples wound around a 11X11X3.75 mm drum core.

[0053] The above description relates to an embodiment of the present invention. Those skilled in this technical field can conceive various modifications of the present invention, but all of them are included in the technical scope of the present invention. The numbers in parentheses described after the components of the claims correspond to the component numbers in the drawings and are attached for the easy understanding of the invention and should not be used for limiting the interpretation of the invention. Also, even with the same number, the component names in the specification and the claims are not necessarily the same. This is due to the reasons described above. "At least one or more", "and / or" are not limited to one of them. For example, "at least one of A, B, C" may include not only "A", "B", "C" alone but also a plurality of them such as "A, B or B, C or further A, B, C". "At least one of A, B, C" may be not only A, B, C alone but also a combination of A and B or a combination of A, B, and C. "A, B and / or C" may include not only A, B, C alone but also two of A and B or all of A, B, and C. In this specification, "including A" and "having A" may include things other than A. Unless otherwise specified, the number of devices or means may be singular or plural.

Explanation of Signs

[0054] 1: Multi - frequency antenna 10: Connection box 11: External connector 12: Coil 13: Common ground 15: Intermediate connector 16: Interconnecting connector

Claims

1. In an antenna system having a multi-band 3D universal antenna, * a magnetic core surrounded by a multi-axis coil wound around each of three orthogonal axes (X-axis, Y-axis, Z-axis), The multi-axis coil has a plurality of types of coils (12) wound around each of the three orthogonal axes, Each coil (12) of each axis has a predetermined cross-sectional area and a predetermined number of turns, Each of the coils (12) of each axis has a different cross-sectional area and number of turns, Each coil has two external connectors (11), * a support member for insulating and holding the coil (12), * a connection box (10) connected to the external connector (11) of the coil having, The connection box (10) provides a reconfigurable interconnect (16) between the external connectors (11), whereby separate external interconnections of the external connectors (11) are established using the connection box (10), forming a plurality of separate antenna coil circuits, The established separate external interconnections are (i) within a range of a predetermined inductance, (ii) within a range of a predetermined quality factor Q, and (iii) formed according to a range of a predetermined sensitivity, operating at three or more operating frequencies An antenna system having a multi-band 3D universal antenna, characterized in that.

2. The multi-band 3D universal antenna is a receiving antenna, The connection box (10) responds to an operating frequency radiated from a neighboring area The antenna system according to claim 1, characterized in that.

3. The three or more operating frequencies are within the RFID band The antenna system according to claim 1, characterized in that.

4. The three or more operating frequencies are 20 kHz, 125 kHz, 134.2 kHz The antenna system according to claim 1, characterized in that.

5. The inductance range for a frequency of 20 kHz is 20 mH, The inductance range for a frequency of 125 kHz or 134.2 kHz is between 2.38 mH and 7.2 mH The antenna system according to claim 1, characterized in that.

6. The quality factor Q for a frequency of 20 kHz is 3.5 or more, The quality factor Q for a frequency of 125 kHz is 15 or more, The quality factor Q for a frequency of 134.2 kHz is 30 or more The antenna system according to claim 4, characterized in that...

7. The sensitivity to a frequency of 20 kHz is 22 mV / A / m, and the sensitivity to a frequency of 125 kHz or 134.2 kHz is between 70 and 80 mV / A / m The antenna system according to claim 4, characterized in that...

8. In the antenna system according to claim 4, it has six coils (12X1, 12Y1, 12Z1, 12X2, 12Y2, 12Z2) arranged around the three orthogonal axes (X-axis, Y-axis, Z-axis), and the first set of three coils (12X1, 12Y1, 12Z1) within the six coils have a cross-sectional area and number of turns such that they operate at a frequency of 125 kHz or 134.2 kHz, and the other three coils (12X2, 12Y2, 12Z2) of the second set have a cross-sectional area and number of turns such that they operate at a frequency of 20 kHz, the interconnection of the external connectors (11) of the six coils provides at least one of the first to fourth antenna circuits * The first antenna coil circuit provides a common ground (13) between the X-axis coils (12X1, 12X2), between the Y-axis coils (12Y1, 12Y2), and between the Z-axis coils (12Z1, 12Z2), resulting in seven external connections being formed in the connection box (10), * The second antenna coil circuit provides intermediate connectors (15) between the X-axis coils (12X1, 12X2), between the Y-axis coils (12Y1, 12Y2), and between the Z-axis coils (12Z1, 12Z2), resulting in nine external connections being formed in the connection box (10), * The third antenna coil circuit provides a common ground (13) at one end of the first set of three coils (12X1, 12Y1, 12Z1) and intermediate connectors (15) between the X-axis coils (12X1, 12X2), between the Y-axis coils (12Y1, 12Y2), and between the Z-axis coils (12Z1, 12Z2), resulting in seven external connections being formed in the connection box (10), *The fourth antenna coil circuit has a first common ground (13) that shares one end of the three coils (12X1, 12Y1, 12Z1) of the first set, and a second common ground (13) that shares one end of the other three coils (12X2, 12Y2, 12Z2) of the second set, and as a result, eight external connections are formed in the connection box (10). The antenna system according to claim 4, characterized in that. **Claim 9** A multi-band antenna (1) is housed in the connection box (10). The antenna system according to claim 1, characterized in that. **Claim 10** The connection box (10) is an integrated circuit. The antenna system according to claim 9, characterized in that.

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