WO2011048728A1

WO2011048728A1 - Near field communication apparatus, and semiconductor integrated circuit for near field communication

Info

Publication number: WO2011048728A1
Application number: PCT/JP2010/004389
Authority: WO
Inventors: 定行英一
Original assignee: パナソニック株式会社
Priority date: 2009-10-19
Filing date: 2010-07-05
Publication date: 2011-04-28
Also published as: JP2011087229A

Abstract

Disclosed is a near field communication apparatus which includes: a first resonant circuit including a first antenna; a reader/writer functional section, which generates alternating current signals of predetermined output by means of predetermined start-up signals, and supplies the alternating current signals to the first resonant circuit; and a second antenna. Furthermore, the near field communication apparatus is provided with: a second resonant circuit which is synchronized with the first resonant circuit with electromagnetic induction between the first antenna and the second antenna; a non-contact IC card functional section which generates predetermined electric information by means of the synchronization of the second resonant circuit; and a resonant circuit adjusting section, which adjusts the resonance characteristics of the first resonant circuit or those of the second resonant circuit, based on predetermined electric information generated in the non-contact IC card functional section.

Description

Near field communication device and semiconductor integrated circuit for near field communication

The present invention relates to a short-range wireless communication device including a reader / writer function unit and a non-contact IC card function unit, and in particular, when adjusting resonance characteristics such as a resonance frequency, The present invention relates to a technique for enabling adjustment to be completed only by the short-range wireless communication device without requiring another device (such as a reader / writer device or a reference card for a non-contact IC card). The present invention also relates to a semiconductor integrated circuit for short-range wireless communication having the same purpose.

In the field of non-contact IC cards, standards such as ISO / IEC14443 and JISX6319-4 exist as standards. A non-contact IC card usually includes a coiled antenna, and performs non-contact communication by electromagnetic induction between the antenna and a reader / writer device having another similar coil antenna. In order for contactless communication to be performed appropriately, it is necessary that the resonance frequencies of the antennas of both the contactless IC card and the reader / writer device are appropriately adjusted. If the resonance frequency is not appropriate, a sufficient communication distance cannot be ensured, resulting in trouble in use.

Normally, the resonance frequency is set to an appropriate value at the stage of antenna design. However, there may be a case in which the desired communication distance performance cannot be ensured at the manufacturing stage due to variations in the resonance frequency due to variations in resonance capacitance or antenna inductance. Arise.

Patent Documents

1 and 2 include conventional techniques for adjusting the resonance frequency of an antenna.

FIG. 19 is a block diagram of the non-contact IC card described in Patent Document 1. The non-contact IC card 10 includes a resonance circuit 11 including an antenna L and an IC chip 17. The IC chip 17 includes a tuning capacitor C1, a correction capacitor C2, a rectifier circuit 12, a shunt regulator 13, a CPU 14, a nonvolatile memory 15, and a general-purpose register 16. In the non-contact IC card 10, the reception voltage detected by the shunt regulator 13 is measured while switching the capacitance value of the correction capacitor C2, and the capacitance value of the correction capacitor C2 is determined by the CPU 14 so that the reception voltage becomes maximum. .

Patent Document 2 describes another method for adjusting the resonance frequency of a non-contact IC card. In the resonant frequency adjustment method, not only the detection of the reception voltage but also the frame error rate of the reception data received from the reader / writer device (the result of checking the data consistency by the parity added to the reception data), Adjust the resonance frequency.

Patent Document 3 describes a resonance frequency adjustment method for a reader / writer device. In the resonance frequency adjustment method, the reference card of the non-contact IC card is placed at a fixed position (for example, the maximum stable communication distance), and the reader / writer device is set to the adjustment mode. The reader / writer device communicates with the reference card while switching the resonance frequency, determines the setting of the resonance frequency at which communication can be performed most stably, and stores the setting content.

In recent years, the NFC (Near Field Communication) standard compatible with the above-mentioned standard has been established as the standard ISO / IEC18092. A device that supports the NFC standard has both a non-contact IC card side function and a reader / writer side function, and a plurality of communication modes such as a reader mode, a card emulation mode, and a peer-to-peer mode (communication between NFC devices). Non-contact communication is performed by electromagnetic induction between antennas with a non-contact IC card, a reader / writer device or another NFC device.

JP 2003-67693 A JP 2002-334310 A JP 2007-60526 A

However, in the short-range wireless communication device including the reader / writer function unit and the non-contact IC card function unit, when adjusting the resonance frequency of the resonance circuit on the non-contact IC card function unit side, When adjusting the resonance frequency of the resonance circuit, there are the following problems in applying the conventional resonance frequency adjustment mechanism.

When adjusting the resonance frequency of the resonance circuit on the non-contact IC card function unit side, a reader / writer device or a measuring device is required outside the short-range wireless communication device to be adjusted. On the other hand, when adjusting the resonance frequency of the resonance circuit on the reader / writer function unit side, another device for adjustment such as a reference card for a non-contact IC card is required.

That is, in order to adjust the resonance frequency, it is necessary to introduce another device for adjustment (a reader / writer device, a reference card for a non-contact IC card, etc.) into the manufacturing process. Furthermore, if the other device is a reader / writer device, the output power needs to be set appropriately, and if it is a reference card, the reception performance needs to be set appropriately. Work is required. For these reasons, the conventional technique has a problem that it takes a lot of cost and labor.

The present invention was created in view of such circumstances, and in a short-range wireless communication device including a reader / writer function unit and a non-contact IC card function unit, another device (a reader / writer device or a non-writer) is externally provided. An object of the present invention is to automatically adjust the resonance characteristics of the resonance circuit without preparing a contact IC card reference card or the like, and without performing preparatory work such as adjustment and calibration.

The present invention solves the above problems by taking the following measures.

The short-range wireless communication device according to the present invention includes a reader / writer function unit and a non-contact IC card function unit. A first resonance circuit is connected to the reader / writer function unit, and a second resonance circuit is connected to the non-contact IC card function unit. That is, the reader / writer function unit and the non-contact IC card function unit each have a separate resonance circuit. The first antenna is included in the first resonance circuit. The second antenna is included in the second resonance circuit. The resonant circuit is separated from the reader / writer function unit by non-tuning the first resonant circuit and the second resonant circuit via electromagnetic induction between the first antenna and the second antenna. This is to connect the contact IC card function unit. The reader / writer function unit generates an AC signal having a predetermined output in response to a predetermined activation signal, and supplies the generated AC signal to the first resonance circuit. The non-contact IC card function unit generates predetermined electrical information by tuning the first resonance circuit and the second resonance circuit. The electrical information may be analog or digital. In the present invention, a resonance circuit adjustment unit is further provided. The resonant circuit adjustment unit is configured to perform the first resonant circuit and the second resonant circuit based on electrical information generated in the non-contact IC card function unit as a result of tuning between the first resonant circuit and the second resonant circuit. The circuit is configured to adjust the resonance characteristics of at least one of the circuits.

The technical feature is that the reader / writer function unit and the non-contact IC card function unit in the short-range wireless communication device operate simultaneously. Further, a technique in which the short-range wireless communication device receives electromagnetic waves generated in the first resonance circuit on the reader / writer function unit side by the second resonance circuit on the non-contact IC card function unit side of the same short-range wireless communication device. Characteristic. The electromagnetic wave generation source and the electromagnetic wave receiving unit are provided in the same short-range wireless communication device. Thus, when the non-contact IC card function unit is mainly considered, a reader / writer device and a measuring device are not required externally as in the prior art. This is because the short-range wireless communication device itself has a reader / writer function unit. Further, when the reader / writer function unit is mainly considered, a reference card for a non-contact IC card is not required externally as in the prior art. This is because the short-range wireless communication device itself has a non-contact IC card function unit.

The electromagnetic wave emitted by itself is received by itself, and as a result, predetermined electrical information obtained by the non-contact IC card function unit is given to the resonance circuit adjustment unit. The resonance circuit adjusting unit adjusts the resonance characteristics of the first resonance circuit and / or the second resonance circuit based on the given electrical information.

In short, the short-range wireless communication device of the present invention is
A first resonant circuit including a first antenna;
A reader / writer function unit that generates an AC signal having a predetermined output in response to a predetermined activation signal and supplies the AC signal to the first resonance circuit;
A second resonant circuit including a second antenna and tuned to the first resonant circuit via electromagnetic induction between the first antenna and the second antenna;
A non-contact IC card function unit that generates predetermined electrical information by tuning the second resonant circuit;
A resonance circuit adjustment unit that adjusts resonance characteristics of the first resonance circuit or the second resonance circuit based on predetermined electrical information generated in the non-contact IC card function unit;
It is equipped with.

According to the above configuration of the present invention, in the short-range wireless communication device including the reader / writer function unit and the non-contact IC card function unit, the predetermined electrical information obtained by receiving the electromagnetic wave generated by the device itself. Is provided to the resonance circuit adjustment unit to adjust the resonance characteristics, so that equipment other than the short-range wireless communication device (reader / writer device, non-contact IC card reference card, etc.) is prepared, and adjustment / calibration, etc. Thus, it is possible to automatically adjust the resonance characteristics of the resonance circuit without requiring any preparation work.

In connection with the short-range wireless communication apparatus of the present invention described above, the short-range wireless communication semiconductor integrated circuit of the present invention is configured by integrating the short-range wireless communication apparatus on a semiconductor.

According to the present invention, in the short-range wireless communication device including the reader / writer function unit and the non-contact IC card function unit, another device (a reader / writer device, a reference card for the non-contact IC card, etc.) is prepared outside. In addition, the resonance characteristics of the resonance circuit can be automatically adjusted without requiring preparation work such as adjustment and calibration, and the cost of the short-range wireless communication apparatus can be reduced.

FIG. 1 is a block diagram showing the configuration of the short-range wireless communication apparatus according to the first embodiment of the present invention. FIG. 2 is a block diagram (No. 1) showing the configuration of the short-range wireless communication apparatus according to the first embodiment. FIG. 3 is a block diagram (part 2) illustrating the configuration of the short-range wireless communication device according to the first embodiment. FIG. 4 is a block diagram (part 3) illustrating the configuration of the short-range wireless communication device according to the first embodiment. FIG. 5 is a block diagram (part 4) illustrating the configuration of the short-range wireless communication device according to the first embodiment. FIG. 6 is a block diagram (No. 5) showing the configuration of the short-range wireless communication apparatus according to the first embodiment. FIG. 7 is a diagram showing an example of a configuration of a mobile phone (19th to 23rd embodiments of the present invention) to which the short-range wireless communication apparatus of the present invention can be applied. FIG. 8 is a block diagram showing a configuration of a short-range wireless communication apparatus according to the nineteenth embodiment of the present invention. FIG. 9 is a pattern diagram showing the positional relationship between the first antenna and the second antenna of the short-range wireless communication apparatus according to the nineteenth embodiment of the present invention. FIG. 10 is a flowchart showing the operation of automatic resonance frequency adjustment according to the nineteenth embodiment of the present invention. FIG. 11 is a table showing the relationship between switch setting variables and switches according to the nineteenth embodiment of the present invention. FIG. 12 is a graph showing the difference in the state of the received voltage when adjusting the resonance frequency according to the antenna design of the present invention. FIG. 13 is a flowchart showing the operation of automatic resonance frequency adjustment in the present invention. FIG. 14 is a block diagram showing a configuration of a short-range wireless communication apparatus according to the twentieth embodiment of the present invention. FIG. 15 is a block diagram showing a configuration of a short-range wireless communication apparatus according to the twenty-first embodiment of the present invention. FIG. 16 is a flowchart showing the operation of automatic resonance frequency adjustment according to the twenty-first embodiment of the present invention. FIG. 17 is a table showing examples of data correct / incorrect results and determination results according to the twenty-first embodiment of the present invention. FIG. 18 is a block diagram showing a configuration of a short-range wireless communication apparatus according to the twenty-second embodiment of the present invention. FIG. 19 is a block diagram showing the configuration of a non-contact IC card in the prior art.

Embodiments of the short-range wireless communication apparatus described in the above section [Means for Solving the Problems] will be described.

(First embodiment)
First, a first embodiment as a basis of a short-range wireless communication apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the short-range wireless communication apparatus according to the first embodiment of the present invention. In FIG. 1, E1 is a reader / writer function unit whose main function is a function as a reader / writer, E2 is a non-contact IC card function unit whose function is a non-contact IC card, and R1 is a reader / writer function unit. A first resonance circuit associated with E1, and R2 is a second resonance circuit associated with the non-contact IC card function unit E2. The first resonance circuit R1 includes a first antenna A1. The second resonance circuit R2 includes a second antenna A2. The reader / writer function unit E1 is configured to generate an AC signal Sac having a predetermined output when a predetermined activation signal Son is input, and to supply the generated AC signal Sac to the first resonance circuit R1. Note that the first antenna A1 may be configured so as to be freely connected to and separated from the first resonance circuit R1. Further, the second antenna A2 may be configured so as to be freely connected to and separated from the second resonance circuit R2. The first resonance circuit R1 and the second resonance circuit R2 are configured to be tuned via electromagnetic induction between the first antenna A1 and the second antenna A2.

The non-contact IC card function unit E2 is configured to generate predetermined electrical information Si through tuning of the second resonance circuit R2. The predetermined electrical information Si is an analog predetermined electric quantity such as a reception level generated inside or outside the second resonance circuit R2, or digital predetermined data such as reception data. To do. In the case of receiving data, a carrier AC signal modulated with transmission data in the reader / writer function unit E1 is supplied to the first resonance circuit R1. A carrier AC signal modulated by the transmission data received by the second resonance circuit R2 is used as the electrical information Si.

E3 is a resonance circuit adjustment unit. The resonance circuit adjustment unit E3 resonates with the first resonance circuit R1 or the second resonance circuit R2 based on the electrical information Si (analog electric quantity or digital data) generated in the non-contact IC card function unit E2. It is configured to adjust the characteristics. When the electrical information Si is received data, the resonance characteristics are adjusted in accordance with a determination result accompanied by a determination of whether the received data is correct (determining a mismatch with the original transmission data). Note that a block 50 surrounded by a broken line in FIG. 1 represents a region of a semiconductor integrated circuit described later (the same applies to FIGS. 2 to 6).

Next, the operation of the short-range wireless communication apparatus of this embodiment will be described. The reader / writer function unit E1 and the non-contact IC card function unit E2 in the short-range wireless communication device are simultaneously set to the operating state. When the activation signal Son is input to the reader / writer function unit E1, the reader / writer function unit E1 generates an AC signal Sac having a predetermined output and supplies it to the first resonance circuit R1. The first resonance circuit R1 operates in accordance with the input AC signal Sac, and generates an AC magnetic field from the first antenna A1. The second antenna A2 is electromagnetically coupled with the alternating magnetic field, and the second resonance circuit R2 is tuned. As described above, the technical point is that the second resonance circuit R2 on the non-contact IC card function unit E2 side of the same short-range wireless communication device receives the electromagnetic wave generated in the first resonance circuit R1 on the reader / writer function unit E1 side. It has become. By the tuning of the second resonance circuit R2, the non-contact IC card function unit E2 generates electrical information Si, and the electrical information Si is given to the resonance circuit adjustment unit E3. Based on the received electrical information Si, the resonance circuit adjustment unit E3 performs the first resonance circuit R1 and the second resonance circuit R2 via electromagnetic induction between the first antenna A1 and the second antenna A2. The resonance characteristics of the first resonance circuit R1 or the second resonance circuit R2 are adjusted so that the resonance operation between the first resonance circuit R1 and the second resonance circuit R2 is optimized.

The technical feature of this short-range wireless communication device is that it receives the AC magnetic field transmitted by itself in the process of optimizing the resonance characteristics. For this purpose, a first resonance circuit R1 including a first antenna A1 and a second resonance circuit R2 including a second antenna A2 are provided. The first resonance circuit R1 including the first antenna A1 is a side that transmits an alternating magnetic field, and is connected to the reader / writer function unit E1. The reader / writer function unit E1 functions to transmit an alternating magnetic field from the first antenna A1 to the second antenna A2 in the process of optimizing the resonance characteristics. The second resonance circuit R2 including the second antenna A2 receives the AC magnetic field, and is connected to the non-contact IC card function unit E2. The non-contact IC card function unit E2 functions to obtain electrical information Si from the second resonance circuit R2 in the process of optimizing the resonance characteristics. Further, the non-contact IC card function unit E2 is connected to the resonance circuit adjustment unit E3, and the resonance circuit adjustment unit E3 controls the first resonance circuit R1 and / or the second resonance circuit R2 to optimize the resonance characteristics. To do. That is, the short-range wireless communication device receives information on its own internal state transmitted by itself and uses it for optimization of resonance characteristics. The information transmission path utilized in this case is not the inside of the apparatus, but an external space (electromagnetic field) from the first antenna A1 to the second antenna A2. The external space is, of course, a space in which the short-range wireless communication device communicates wirelessly with another short-range wireless communication device, a contactless IC card, or a reader / writer device. The resonance characteristics are adjusted according to the situation.

In the case of conventional technology, there is only one resonance circuit and one antenna. When the device is regarded as a non-contact IC card, an alternating magnetic field transmitted from an external reader / writer device is captured by the antenna. The resonance characteristics of the resonance circuit are adjusted based on the electrical information. When the device is regarded as a reader / writer device, the resonance circuit of the reader / writer device is oscillated, the AC magnetic field transmitted from the antenna is received by an external non-contact IC card, and responds with load modulation. The incoming information is received by the reader / writer device, and the resonance characteristics of the resonance circuit are adjusted based on the received electrical information. In the former case, a reader / writer device is required outside, and in the latter case, a non-contact IC card is required outside. Moreover, the prepared reader / writer device is required to appropriately set the output power. In the reference card, work for appropriately setting reception performance and the like has been demanded. After all, there was a problem that it took a lot of costs and labor. Such a problem recognized in the prior art is solved in the present embodiment.

According to the configuration of this embodiment, when the non-contact IC card function unit E2 is considered as a center, no external reader / writer device is required. This is because the short-range wireless communication device itself has the reader / writer function unit E1 and the first resonance circuit R1. Further, when the reader / writer function unit E1 is considered as the center, a non-contact IC card reference card is not required outside. This is because the short-range wireless communication device itself has the non-contact IC card function unit E2 and the second resonance circuit R2.

Receiving the electromagnetic wave emitted by itself, as a result, predetermined electrical information SiＳ (analog electric quantity or digital data) obtained by the non-contact IC card function unit E2 is given to the resonance circuit adjustment unit E3, and the resonance The circuit adjustment unit E3 adjusts the resonance characteristics of the first resonance circuit R1 or the second resonance circuit R2 based on the electrical information Si. Adjustment of resonance characteristics means adjustment of resonance frequency, adjustment of quality factor (Q value: sharpness of resonance), or both. The adjustment of the resonance frequency may be performed through a change in resonance capacitance or through a change in inductance. The quality factor (Q value) is adjusted by changing the resistance value.

The following explains the factors for adjusting the resonance characteristics as circuit factors. Before adjustment, the circuit factor of the first resonance circuit R1 is α11, and the circuit factor of the second resonance circuit R2 is α21. α11 and α21 are resonance frequency and / or quality factor (Q value). In the aspect in which the resonance circuit adjusting unit E3 adjusts the first resonance circuit R1 based on the predetermined electrical information Si, the circuit factor is adjusted as α11 → α12. In the aspect in which the resonance circuit adjustment unit E3 adjusts the second resonance circuit R2 based on the predetermined electrical information Si 情報, the circuit factor is adjusted as α21 → α22.

As described above, the short-range wireless communication device of the present embodiment is
A first resonant circuit R1 including a first antenna A1,
A reader / writer function unit E1 that generates an AC signal Sac having a predetermined output in response to a predetermined activation signal Son and supplies the AC signal Sac to the first resonance circuit R1;
A second resonant circuit R2 including a second antenna A2 and tuned to the first resonant circuit R1 via electromagnetic induction between the first antenna A1 and the second antenna A2,
A non-contact IC card function unit E2 that generates predetermined electrical information Si by tuning of the second resonance circuit R2,
A resonance circuit adjusting unit E3 for adjusting the resonance characteristics of the first resonance circuit R1 or the second resonance circuit R2 based on predetermined electrical information Si generated in the non-contact IC card function unit E2,
It is equipped with.

According to the present embodiment, in the short-range wireless communication device provided with the reader / writer function unit E1 and the non-contact IC card function unit E2, it receives the electromagnetic waves generated by itself and obtains the predetermined electrical Since the information Si is given to the resonance circuit adjustment unit E3 to adjust the resonance characteristics, other equipment (reader / writer device, non-contact IC card reference card, etc.) is prepared outside, and preparation work such as adjustment / calibration is performed. The resonance characteristics of the resonance circuit can be automatically adjusted without the need for cost reduction of the short-range wireless communication device.

The resonance characteristic automatic adjustment for the short-range wireless communication device may be performed at the manufacturing stage or at the time of actual use by the user. In that case, it is preferable to be configured to start with a startup signal at the time of power-on accompanying the start of use of the apparatus.

The above is an explanation of the operation of automatic adjustment of resonance characteristics for a short-range wireless communication device. Next, normal operation in actual use of the short-range wireless communication device will be described. First, an operation when the short-range wireless communication apparatus operates in the reader mode and performs wireless communication with an external non-contact IC card will be described. At this time, an electromagnetic wave modulated by digital data is transmitted from the short-range wireless communication apparatus, and the external non-contact IC card receives the electromagnetic wave. In the reader mode, the reader / writer function unit E1 operates in the short-range wireless communication device, but the non-contact IC card function unit E2 does not operate. At the time of data transmission in the reader mode, in the short-range wireless communication device, the transmission data is transmitted to the modulation circuit e11 (see FIG. 2) of the reader / writer function unit E1, and the AC signal Sac modulated by the modulation circuit e11 is the first. Is supplied to the first antenna A1 of the resonance circuit R1, and an electromagnetic wave accompanied by transmission data is emitted. In an external non-contact IC card on the communication partner side, current flows due to electromagnetic waves received by the loop antenna. The rectifier obtains a DC voltage and supplies power to each part. Further, the reception data superimposed is demodulated by a demodulation circuit. When an external non-contact IC card responds, the impedance of the loop antenna is switched by load modulation, and is received by the first antenna A1 of the short-range wireless communication device by electromagnetic coupling, and the first resonance circuit R1 Is demodulated by the demodulation circuit e12.

Next, the operation when the short-range wireless communication apparatus operates in the card emulation mode and performs wireless communication with an external reader / writer apparatus will be described. At this time, in the short-range wireless communication device, the non-contact IC card function unit E2 operates, but the reader / writer function unit E1 does not operate. When receiving data in the card emulation mode, the electromagnetic wave from the external reader / writer device is received by the second antenna A2, and the received voltage is applied to the rectifier e21 of the non-contact IC card function unit E2 via the second resonance circuit R2. Occurs. The received voltage covers the power of each part. Further, the demodulating circuit e22 demodulates data included in the received signal. When responding, the load modulation unit e23 is driven with the transmission data, and the transmission data is transmitted to the external reader / writer device via the second antenna A2 of the second resonance circuit R2.

Next, a peer-to-peer mode, which is a communication mode between short-range wireless communication devices, will be described. In the peer-to-peer mode, a short-range wireless communication device that first transmits data (command) is called an initiator, and a short-range wireless communication device that is a destination of the data is called a target. In the peer-to-peer mode, there are two types of modes, a passive communication mode and an active communication mode.

In the passive communication mode, when transmitting data from the initiator to the target, the initiator operates in the same manner as the reader mode described above, and the target operates in the same manner as the card emulation mode described above. When responding from the target to the initiator, the target operates in the same manner as in the card emulation mode, and the initiator operates in the same manner as in the reader mode. That is, the target responds to the initiator by load modulation.

Next, in the active communication mode, when data is transmitted from the initiator to the target, it is the same as the passive communication mode, the initiator operates the same as the reader mode, and the target operates the same as the card emulation mode. The difference is when a response is made from the target to the initiator. At this time, the target performs the same operation as the reader mode, and the initiator performs the same operation as the card emulation mode. That is, the target does not use load modulation, and responds to the initiator by sending out electromagnetic waves modulated with response data in the reader mode.

In the peer-to-peer mode, in either the active communication mode or the passive communication mode, the initiator or target, the initiator data transmission or the target data response, the reader / writer function unit E1 or the non-contact IC in the short-range wireless communication device Only one of the card function units E2 operates, and there is no state in which both function units operate simultaneously.

This completes the description of the first embodiment. The short-range wireless communication apparatus having the configuration of the first embodiment described above is the basic configuration of the present invention, and can be further advantageously developed in the following embodiment.

(Second Embodiment)
In the present embodiment, in the short-range wireless communication device of the first embodiment, the resonance circuit adjustment unit E3 is further configured based on predetermined electrical information Si generated in the non-contact IC card function unit E2. The resonance characteristics of both the resonance circuit R1 and the second resonance circuit R2 are adjusted. The keyword here is “adjusting the resonance characteristics of both the first resonance circuit and the second resonance circuit”. That is, the circuit factor of the first resonance circuit R1 is adjusted as α11 → α12, and the circuit factor of the second resonance circuit R2 is adjusted as α21 → α22. In this case, the resonance circuit adjustment unit E3 adjusts the resonance characteristics of both the first resonance circuit R1 and the second resonance circuit R2, so that the first resonance circuit R1 and the second resonance circuit R2 are connected. Optimize the resonant operation of As a result, it is possible to optimize by eliminating the excess and deficiency of the transmission capability in the reader / writer function unit E1, and at the same time to eliminate and optimize the excess and deficiency of the reception capability in the non-contact IC card function unit E2.

(Third embodiment)
In the present embodiment, in the short-range wireless communication devices of the first and second embodiments, the reader / writer function unit E1 further generates an unmodulated constant-current AC signal Sac as an AC signal Sac having a predetermined output. As shown in FIG. 2, the non-contact IC card function unit E2 includes an AD converter e24 connected to a rectifier e21 connected to the second resonance circuit R2, and has predetermined electrical information. As Si, a voltage obtained by digitally converting the voltage appearing on the output side of the rectifier e21 by the AD converter e24 is used. Here, “AD converter” is a keyword.

The carrier voltage signal obtained by tuning the second resonance circuit R2 is rectified by the rectifier e21 and a rectified voltage is output. This is the received voltage. The received voltage is digitally converted by the AD converter e24, and the digital data is supplied to the resonance circuit adjusting unit E3 as electrical information SiＳ. The resonance circuit adjustment unit E3 adjusts the resonance characteristics of the second resonance circuit R2 or the first resonance circuit R1 so that the reception voltage corresponds to the maximum value.

In FIG. 2, e11 is a modulation circuit generally provided in the reader / writer function unit E1, e12 is a demodulation circuit, e22 is a demodulation circuit generally provided in the non-contact IC card function unit E2, and e23 is Similarly, a load modulation unit, e25, is a shunt circuit.

(Fourth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first and second embodiments, the reader / writer function unit E1 further applies a signal obtained by amplitude modulation of a carrier wave by a built-in modulation circuit e11 with a certain modulation factor. The non-contact IC card function unit E2 is configured to generate an AC signal Sac of the output of the rectifier e21 connected to the output side of the second resonance circuit R2, and the AD converter e24 connected to the rectifier e21. As the predetermined electrical information S i, the voltage fluctuation difference that appears on the output side of the rectifier e21 is digitally converted by the AD converter e24. Here, “AD converter” and “amplitude modulation of the carrier wave with a constant modulation degree” and “difference in voltage fluctuation” are the keywords. In this configuration, the difference between the reception voltage at the time of non-modulation and the reception voltage at the time of modulation is measured, and the resonance characteristics are adjusted so that the difference becomes the largest.

(Fifth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first and second embodiments, the reader / writer function unit E1 further generates an unmodulated constant-current AC signal Sac as an AC signal Sac having a predetermined output. The non-contact IC card function unit E2 is configured to generate a shunt circuit e25 and an AD converter e24 connected to a rectifier e21 connected to the second resonance circuit R2, and as predetermined electrical information Si, A shunt current flowing in the shunt circuit e25 is digitally converted by the AD converter e24. Here, “shunt circuit” is a keyword along with “AD converter”.

The shunt circuit e25 suppresses an excessive voltage rise by causing a current to flow to the ground when the received voltage becomes a predetermined voltage or higher under a strong magnetic field. In the third embodiment, the reception voltage of the output of the rectifier e21 is used for the determination of the reception level. Instead, the current flowing through the shunt circuit e25 is used for the determination of the reception level. The carrier voltage signal obtained by tuning the second resonance circuit R2 is rectified by the rectifier e21, and a shunt current corresponding to the received voltage flows to the shunt circuit e25. The shunt current is digitally converted by the AD converter e24, and the digital data is supplied to the resonance circuit adjustment unit E3 as electrical information Si. The resonance circuit adjustment unit E3 adjusts the resonance characteristics of the second resonance circuit R2 or the first resonance circuit R1 so that the shunt current corresponds to the maximum value.

(Sixth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first and second embodiments, as shown in FIG. 3, the reader / writer function unit E1 uses a built-in modulation circuit e11 to transmit a carrier wave to predetermined transmission data. The non-contact IC card function unit E2 generates received data corresponding to the transmission data appearing in the built-in demodulation circuit e22 as predetermined electrical information. Used as Si. Here, “transmission data” and “reception data corresponding to the transmission data appearing in the demodulation circuit” are keywords.

Since the determination is performed using the received data demodulated by the demodulation circuit e22 inherently included in the non-contact IC card function unit E2, the output of the rectifier e21 of the third to fifth embodiments described above is used. The AD converter e24 required for determination by voltage measurement is not required, resonance characteristic adjustment can be realized with a smaller circuit configuration, and costs can be further suppressed.

(Seventh embodiment)
In the present embodiment, in the short-range wireless communication device of the sixth embodiment, the resonance circuit adjustment unit E3 further determines whether the received data in the non-contact IC card function unit E2 matches or does not match the transmission data. The resonance characteristic adjustment process is executed through the control unit.

The resonance circuit adjustment unit E3 optimizes the resonance characteristics by performing a process for adjusting the resonance characteristics through a determination as to whether or not the received data of the demodulation result matches the original transmission data. In determining whether the resonance characteristics are optimal, it is based on whether the received data and the transmitted data match or not, so if you want to make a determination based on a check code such as parity or CRC (Cyclic Redundancy Check) or request command The determination can be performed more accurately than in the case where the determination is made based on whether or not a response to the transmission is received.

(Eighth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first to seventh embodiments, as shown in FIG. 4, the reader / writer function unit E1 further adjusts the intensity of the AC signal Sac having a predetermined output. And an output adjuster e13 that determines the setting of the output adjuster e13 based on predetermined electrical information Si. Here, “output adjuster” and “determination unit” are keywords.

In the process of optimizing the resonance characteristics, the factor is switched to a plurality of stages, and it is determined at which stage the reception level is maximized among the plurality of stages. The reception level rises due to the sequential switching of factors, and then begins to fall. The optimal point is near the peak of the reception level. In order to discriminate the vertex, it is a condition that the change in the reception level is large to some extent. However, when the amplitude of the AC signal Sac emitted from the reader / writer function unit E1 is too large, the reception level is saturated and the change is limited. When the amplitude of the AC signal Sac generated from the reader / writer function unit E1 is too small, the amount of change in the reception level is too small and the change is limited. This makes it difficult to accurately adjust the resonance characteristics.

Therefore, an output adjuster e13 that adjusts the intensity of the AC signal Sac having a predetermined output and a determiner e14 that determines the setting of the output adjuster e13 based on the predetermined electrical information Si are provided. The determiner e14 determines the reception state based on the electrical information Si, and determines the setting of the output adjuster e13 according to the determination result. The output adjuster e13 adjusts the intensity of the AC signal Sac according to the setting. When the reception state is too strong, the strength of the AC signal Sac is lowered. Conversely, when the reception state is too weak, the strength of the AC signal Sac is increased. By such feedback control, for example, the specifications of the first antenna A1 and the second antenna A2 change variously. As a result, even if the reception state fluctuates, the resonance characteristics are always stable regardless of that. Can be adjusted accurately.

Note that the non-contact IC card function unit E2 may use the output of the AD converter e24 as shown in FIG. 2 instead of the output of the demodulation circuit e22 in order to obtain the electrical information Si.

(Ninth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first to seventh embodiments, as shown in FIG. 5, the reader / writer function unit E1 further modulates the modulation degree of the AC signal Sac having a predetermined output. And a determination unit e14 for determining the setting of the modulation degree adjuster e15 based on predetermined electrical information Si.

In the present embodiment, a modulation factor adjuster e15 that adjusts the modulation factor of the AC signal Sac having a predetermined output and a determiner e14 that determines the setting of the modulation factor adjuster e15 based on the predetermined electrical information SiＳ. Is provided. The determiner e14 determines the reception state based on the electrical information Si, and determines the setting of the modulation factor adjuster e15 according to the determination result. The modulation degree adjuster e15 adjusts the modulation degree of the AC signal Sac according to the setting. When the reception state is too strong, the modulation degree of the AC signal Sac is lowered. Conversely, when the reception state is too weak, the modulation degree of the AC signal Sac is increased. By such feedback control, for example, the specifications of the first antenna A1 and the second antenna A2 change variously. As a result, even if the reception state fluctuates, the resonance characteristics are always stable regardless of that. Can be adjusted accurately.

Also in this case, the non-contact IC card function unit E2 may use the output of the AD converter e24 as shown in FIG. 2 instead of the output of the demodulation circuit e22 in order to obtain the electrical information SiＳ. .

(Tenth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first to seventh embodiments, as shown in FIG. 6, the non-contact IC card function unit E2 further adjusts the demodulation sensitivity of the demodulation circuit e22. A demodulation sensitivity adjuster e26 and a determination device e27 that determines the setting of the demodulation sensitivity adjuster e26 based on predetermined electrical information Si.

In the present embodiment, a demodulation sensitivity adjuster e26 that adjusts the demodulation sensitivity of the demodulation circuit e22 and a determination device e27 that determines the setting of the demodulation sensitivity adjuster e26 based on predetermined electrical information SiＳ are provided. . The determiner e27 determines the reception state based on the electrical information Si, and determines the setting of the demodulation sensitivity adjuster e26 according to the determination result. The demodulation sensitivity adjuster e26 adjusts the demodulation sensitivity of the demodulation circuit e22 according to the setting. If the reception state is too strong, the demodulation sensitivity is lowered. Conversely, when the reception state is too weak, the demodulation sensitivity is increased. By such feedback control, for example, the specifications of the first antenna A1 and the second antenna A2 change variously. As a result, even if the reception state fluctuates, the tuning is always stable regardless of this. It can be carried out.

Also in this case, the non-contact IC card function unit E2 may use the output of the AD converter e24 as shown in FIG. 2 instead of the output of the demodulation circuit e22 in order to obtain the electrical information SiＳ. . A combination of the ninth embodiment and the tenth embodiment is also preferable.

(Eleventh embodiment)
In the present embodiment, in the short-range wireless communication devices of the first to tenth embodiments, the reader / writer function unit E1 uses a startup signal of the short-range wireless communication device as the predetermined activation signal Son.

When using the short-range wireless communication apparatus of this embodiment, when the power is turned on, a startup signal is generated and output. The reader / writer function unit E1 is activated by this startup signal. The automatic adjustment of the resonance characteristics is generally performed at the time of manufacturing the mounted product. However, even after the shipment, the resonance characteristics may be automatically adjusted every time, for example, at the start-up when the power switch is turned on. . In this case, since the resonance characteristics can be optimized in accordance with the usage environment, including the temperature condition, etc. every time use is started, the communication distance of the short-range wireless communication device can be further optimized.

(Twelfth embodiment)
In the present embodiment, in the short-range wireless communication devices of the first to eleventh embodiments, the resonance characteristics to be adjusted are resonance frequency, quality factor (Q value), or resonance frequency and quality factor ( Q value).

In the first to eleventh embodiments, the present invention is applied to a short-range wireless communication device. In the twelfth embodiment, the present invention is replaced with a semiconductor integrated circuit for short-range wireless communication. It is developed as a circuit. 1 to 6, a block 50 surrounded by a broken line represents a region of a semiconductor integrated circuit to be described later (the present invention is not limited to this form).

(Thirteenth embodiment)
In the semiconductor integrated circuit for near field communication according to the present embodiment, at least the reader / writer function unit E1, the non-contact IC card function unit E2, and the resonance circuit adjustment in the near field communication devices of the first to twelfth embodiments. The part E3 is integrated on the semiconductor. This is because the constituent elements mounted on the semiconductor integrated circuit only need to have at least a reader / writer function unit E1, a non-contact IC card function unit E2, and a resonance circuit adjustment unit E3. The resonance circuit R1 and the second resonance circuit R2 are not particularly required to be mounted.

(Fourteenth embodiment)
In the present embodiment, in the semiconductor integrated circuit of the thirteenth embodiment, the reader / writer function unit E1 further has a connection terminal of the first resonance circuit R1, and the non-contact IC card function unit E2 has the second resonance. It has a connection terminal for the circuit R2. This is because the semiconductor integrated circuit in which the first resonant circuit R1 including the first antenna A1 and the second resonant circuit R2 including the second antenna A2 are connected to the outside of the semiconductor integrated circuit. It is intended for.

(Fifteenth embodiment)
In the present embodiment, in the semiconductor integrated circuit of the thirteenth embodiment, the first resonance circuit R1 and the second resonance circuit R2 in the short-range wireless communication devices of the first to twelfth embodiments The main part or the whole is provided on the semiconductor. The semiconductor integrated circuit includes a first resonance circuit R1 and a second resonance circuit R2, and each of the first resonance circuit R1 and the second resonance circuit R2 is at least one of an antenna and a resonance capacitor. The idea is to have

(Sixteenth embodiment)
In the present embodiment, in the semiconductor integrated circuit of the fifteenth embodiment, the first resonance circuit R1 further includes a first antenna A1, and the second resonance circuit R2 includes a second antenna A2. . This is to say that although the first resonance circuit R1 and the second resonance circuit R2 are each provided with an antenna, the resonance capacitance to be connected to each antenna is not an essential component per se.

(Seventeenth embodiment)
In the present embodiment, in the semiconductor integrated circuit of the fifteenth embodiment, the first resonance circuit R1 further includes a resonance capacitor, and the second resonance circuit R2 includes a resonance capacitor. This is because the first resonance circuit R1 and the second resonance circuit R2 each have a resonance capacitance, but the first antenna A1 and the second antenna A2 are not essential constituent elements themselves. It is.

(Eighteenth embodiment)
In the present embodiment, in the semiconductor integrated circuit of the fifteenth embodiment, the first resonance circuit R1 further includes the first antenna A1 and the resonance capacitor, and the second resonance circuit R2 includes the second antenna A2 and the second antenna A2. Includes resonant capacitance. This means that each of the first resonance circuit R1 and the second resonance circuit R2 includes a resonance capacitor and an antenna. This also includes the case where parasitic capacitance is used as the resonance capacitance.

In this specification, each component of the reader / writer function unit, the non-contact IC card function unit, the resonance circuit adjustment unit, the output adjustment unit, the modulation degree adjustment unit, and the determination unit is configured by hardware or software. It may consist of individual steps or routines. Or you may comprise by the combination of hardware and software.

Hereinafter, each embodiment showing details of the present invention will be further described with reference to the drawings. The embodiment described below is merely an example, and various modifications can be made.

(Nineteenth embodiment)
In this embodiment, a configuration of a mobile phone to which the short-range wireless communication device of the present invention can be applied is shown.

FIG. 7 is a diagram showing an example of the configuration of the mobile phone according to the 19th to 23rd embodiments to which the short-range wireless communication device of the present invention is applied. The mobile phone 1 shown in FIG. 1 includes an NFC-LSI (Large Scale Integration) 50, a first antenna A1, a resonance capacitor 31, a second antenna A2, a resonance capacitor 41, and a UICC (Universal Integrated Circuit Circuit Card). 60 and an application processor 70.

The mobile phone 1 equipped with the NFC-LSI 50 can communicate with another mobile phone 1 equipped with the same function, the reader / writer device 2 for the non-contact IC card, and the non-contact IC card 3. The mobile phone 1 communicates in peer-to-peer mode when communicating with another mobile phone 1, communicates in card emulation mode when the reader / writer device 2 is used, and communicates in reader mode when the contactless IC card 3 is used. .

In the mobile phone 1, the NFC-LSI 50, the UICC 60, and the application processor 70 are connected to each other via a serial interface or the like. The NFC-LSI 50 executes a front-end process of a non-contact communication interface corresponding to the NFC standard.

In addition to the function of storing mobile phone user management information and phone book data, the UICC 60 performs secure processing such as authentication processing using encryption and card application processing in contactless communication processing using the NFC-LSI 50. Do. For example, when the mobile phone 1 executes a so-called electronic money payment processing application, the NFC-LSI 50 performs only the processing of the contactless communication interface, and the authentication, management information reading, and writing required for the payment processing are performed. Processing is executed in the UICC 60.

Further, the application processor 70 can perform various application processes in the non-contact communication process using the NFC-LSI 50 as well as the UICC 60 in addition to the application process of the entire mobile phone. For example, the NFC-LSI 50 is set to the peer-to-peer mode, the process of exchanging information in the phone book with the external mobile phone 1, the process of setting the reader mode to read the information of the contactless IC card 3, and the display on the display Processing can be performed.

Next, the short-range wireless communication device of this embodiment will be described. In the present embodiment, the resonance frequency of the second resonance circuit R2 on the non-contact IC card function unit E2 side is automatically adjusted. The predetermined electrical information Si uses the reception voltage V1 at the non-contact IC card function unit E2. FIG. 8 is a block diagram showing a configuration of the short-range wireless communication apparatus according to the present embodiment. The embodiment shown in FIG. 8 corresponds to the first, third, eleventh, thirteenth, and fourteenth embodiments described above.

8 will be described in advance. The resonance circuit adjustment unit E3 in FIG. 1 corresponds to the resonance frequency adjustment circuit 102. The activation signal Son corresponds to the signal CAON, the AC signal Sac corresponds to the transmission signal TX, and the electrical information Si 情報 corresponds to the reception voltage V1 or the V1 voltage value VLV. This embodiment corresponds to a type in which the resonance circuit adjustment unit E3 adjusts the resonance characteristics of the second resonance circuit R2.

2 will be described in advance. The modulation circuit e11 in FIG. 2 corresponds to the modulation circuit 82, the demodulation circuit e12 corresponds to the demodulation circuit 84, and the rectifier e21 corresponds to the rectifier 91. The demodulating circuit e22 corresponds to the demodulating circuit 92, the load modulating unit e23 corresponds to the load switch 94, the AD converter e24 corresponds to the AD converter 95, and the shunt circuit e25 corresponds to the shunt circuit 93.

8 includes an NFC-LSI 50, a first antenna (reader / writer antenna) A1, a resonance capacitor 31 connected in series to the first antenna A1, and a second antenna (card antenna). ) A2 and a resonance capacitor 41 connected in parallel to the second antenna A2. The first antenna A1 and the resonance capacitor 31 constitute a first resonance circuit R1, and the second antenna A2 and the resonance capacitor 41 constitute a second resonance circuit R2. The resonance frequency adjusting circuit 102 is inserted between the second resonance circuit R2 and the non-contact IC card function unit E2.

The NFC-LSI 50 is configured as a semiconductor integrated circuit, and includes a reader / writer function unit E1, a non-contact IC card function unit E2, a resonance frequency adjusting circuit 102, a CPU 51, an I / F (Interface) 52, and a ROM (Read It includes only memory (RAM) 53, random access memory (RAM) 54, and non-volatile memory (NVM) 55.

The reader / writer function unit E1 is a block that realizes a reader / writer function in the NFC (Near Field Communication) standard, and the non-contact IC card function unit E2 is a block that realizes a non-contact IC card function in the NFC standard. The CPU 51 controls the reader / writer function unit E1 and the non-contact IC card function unit E2, controls the I / F 52, executes the software stored in the ROM 53, and reads / writes the RAM 54 and nonvolatile memory (NVM) 55. And control. The I / F 52 includes interfaces connected to the UICC 60 and the application processor 70 in FIG. The ROM 53 stores software related to automatic resonance frequency adjustment described later and various software for realizing the NFC function. The RAM 54 is a temporary storage memory necessary for the operation of the CPU 51, and the nonvolatile memory (NVM) 55 stores a resonance frequency adjustment result (to be described later) and various setting data related to the NFC function.

The reader / writer function unit E1 includes a carrier wave generation circuit 81, a modulation circuit 82, a driver 83, and a demodulation circuit 84. The carrier wave generation circuit 81 is a circuit that generates a 13.56 MHz carrier wave, and is controlled to be turned on and off by a signal CAON input from the CPU 51. The modulation circuit 82 is a circuit that performs ASK (Amplitude Shift 変調 Keying) modulation, and modulates the carrier wave signal S0 input from the carrier wave generation circuit 81 with a predetermined modulation degree based on the data of the transmission data signal TXRD to generate a modulated wave signal. S1 is generated. The degree of modulation differs depending on the protocol used. For example, the modulation is performed with ASK 100% in the case of ISO / IEC 14443 Type A, and with ASK 10% in the case of ISO / IEC 14443 Type B. The driver 83 drives the modulated wave signal S1 to the first antenna A1 as the transmission signal TX. In addition, an output setting signal AJPW [l: 0] is input from the CPU 51 to the driver 83 (“l” in [l: 0] is the letter L). The driver 83 is configured such that its driver size is adjusted by the output setting signal AJPW [l: 0]. The demodulating circuit 84 demodulates the data that the external non-contact IC card, for example, responds by load modulation into a digital received data signal RXRD.

The non-contact IC card function unit E2 includes a rectifier 91, a demodulation circuit 92, a shunt circuit 93, a load switch 94, and an AD converter (ADC: Analog-to-Digital Converter) 95. The rectifier 91 rectifies the carrier wave received by the second antenna A2, and generates a reception voltage V1. The demodulation circuit 92 demodulates the ASK modulation data from the reception voltage V1 to a digital reception data signal RXCD. The shunt circuit 93 causes a current to flow from the reception voltage V1 to the ground when the reception voltage V1 is equal to or higher than a predetermined voltage, so that the reception voltage V1 does not increase excessively even under a strong magnetic field. The load switch 94 performs load modulation based on the data of the transmission data signal TXCD, and transmits the data to the external non-contact IC card reader / writer device 2.

The AD converter 95 converts the voltage value of the reception voltage V1 into a V1 voltage value VLV of digital data and outputs it to the CPU 51. The resonance frequency adjusting circuit 102 includes a plurality of capacitors CC0 to CCn and a plurality of switches SC0 to SCn. Each pair of the capacitor CCn and the switch SCn is connected in series between the antenna terminals VA and VB of the second antenna A2 so that the capacitor CCn is in parallel with the resonance capacitor 41. The resonance frequency adjusting circuit 102 is connected to the input side of the rectifier 91 and is connected to the output side of the load switch 94. ON / OFF of the switches SC0 to SCn is controlled by a control signal SCON [n: 0] output from the CPU 51. The minimum value of n is 0. In this case, only CC0 and SC0 are obtained.

In the short-range wireless communication apparatus of the present embodiment, when the resonance frequency is automatically adjusted, the reader / writer function unit E1 and the non-contact IC card function unit E2 are simultaneously set to the operating state, and the first The antenna A1 and the second antenna A2 are electromagnetically coupled, and at the same time, the resonance frequency adjusting circuit 102 can be brought into an operating state. The short-range wireless communication device receives the electromagnetic wave transmitted by its reader / writer function unit E1 by its non-contact IC card function unit E2, and receives the electrical information obtained by reception, that is, the reception voltage generated by the rectifier 91 Information derived from V1 is sent to the resonance frequency adjusting circuit 102 to optimize the resonance frequency.

In FIG. 8, one terminal of the first antenna A1 is grounded, but there is a configuration in which a resonant capacitor is connected in series on both sides of the first antenna A1 and input to the NFC-LSI 50. In addition to the first antenna A1 and the resonance capacitor 31, in order to add a resistor for adjusting the Q value indicating the sharpness of resonance or to adjust the impedance, a capacitor is connected in parallel to the first antenna A1. An LC filter may be added to remove a high-frequency component from the waveform of the driver output TX of the NFC-LSI 50, but these are omitted in this description.

Also, in the second antenna A2, both terminals are connected to the NFC-LSI 50, but there is a method in which one terminal is grounded. Further, although a resistor may be added for Q value adjustment, they are omitted in this description. Further, the NFC-LSI 50 which is a semiconductor integrated circuit may be configured to incorporate the

resonance capacitors

31 and 41.

FIG. 9 is a pattern diagram showing an arrangement relationship between the first antenna A1 and the second antenna A2. In FIG. 9, a first antenna A <b> 1 and a second antenna A <b> 2 are disposed on a substrate 36. The second antenna A2 is formed on the outer peripheral side of the substrate 36, and the first antenna A1 is formed inside the second antenna A2. By arranging as shown in FIG. 9, a carrier wave is output from the first antenna A1, and at the same time, the second antenna A2 can receive the same carrier wave. Note that the arrangement relationship between the first antenna A1 and the second antenna A2 may be opposite to the case of FIG. 9, and the first antenna A1 may be arranged outside. In addition, two antennas may be arranged next to each other, not on the same center, and it is only necessary that the carrier wave output from the first antenna A1 can be simultaneously received by the second antenna A2 in other arrangements.

Next, the operation of the resonance frequency automatic adjustment of the short-range wireless communication apparatus of the present embodiment configured as described above will be described. In the following description, n of the switches SC0 to SCn and capacitors CC0 to CCn is assumed to be n = 2 (n is three of 0 to 2).

FIG. 10 is a flowchart showing the operation of automatic resonance frequency adjustment. This operation is executed by the cooperation of the CPU 51 built in the NFC-LSI 50, the program stored in the ROM 53, and the RAM 54 as a work memory. First, in step S11, when automatic resonance frequency adjustment is started by a command indicating activation of resonance frequency automatic adjustment input to the I / F 52 from the outside of the NFC-LSI 50 or a trigger stored by the software itself stored in the ROM 53, In step S 12, the carrier wave generation signal CAON = H output from the CPU 51 to the carrier wave generation circuit 81 is set, and the carrier wave generation circuit 81 outputs the carrier wave S 0. The transmission data TXRD of the reader / writer function unit E1 is set to zero, and the modulation circuit 82 outputs an unmodulated (same as the carrier wave S0) modulated signal S1 to the driver 83, and from the first antenna A1 has a constant intensity with no modulation. Output magnetic field.

The AC magnetic field output from the first antenna A1 can be simultaneously received by the second antenna A2 by electromagnetic induction between the antennas. One of the technical points of Example 1 is here. The AC magnetic field received by the second antenna A2 is rectified by the rectifier 91, and a certain voltage is output to the reception voltage V1.

Next, in step S13, variable values related to resonance frequency adjustment are initialized. As variables, there are a switch setting variable x and a V1 measurement result V1D (x). For example, as shown in FIG. 11, the switch setting variable x is associated with the value of the switch setting variable x and the on / off relationship of the switches SC0 to SC2. For example, when the capacitance values of the capacitors CC0 to CC2 are 1 pF, 2 pF, and 4 pF, respectively, x = 1 to 8, and the overall capacitance value of the resonance frequency adjusting circuit 102 changes with the transition of x = 1 to 8. 0pF to 7pF, and can be set in units of 1pF. In initialization, x = 1 and V1D (1) to V1D (m) = 0V are set. m is the maximum value, and in this example, m = 8.

After the variable initialization, in step S14, the switch setting variable x is incremented by 1 (x = x + 1), and the switches SC0 to SC2 of the resonance frequency adjusting circuit 102 are set. The switches SC0 to SC2 are controlled by a control signal SCON [2: 0] output from the CPU 51.

Next, in step S15, the reception voltage V1 is measured by the AD converter 95, the digital V1 voltage value VLV is input to the CPU 51, and the CPU 51 stores the V1 voltage value VLV in the V1 measurement result V1D (x) (V1D ( x) = VLV).

Subsequently, in step S16, the CPU 51 compares the V1 measurement result V1D (x) with the previous V1 measurement result V1D (x-1). If the current measurement result is larger, the process proceeds to step S17 to set the switch. It is confirmed whether or not the variable x has reached the maximum value m (= 8). If x is not m, the process proceeds to step S14, the switch setting variable x is incremented by 1 (x = x + 1), and the received voltage V1 is measured. When x = m, the process proceeds to step S18, the resonance frequency optimum value best_adj = x is set, and the resonance frequency adjustment is finished.

On the other hand, if it is determined in step S16 that the previous measurement result is larger, the process proceeds to step S19, the resonance frequency optimum value best_adj = x−1 is set, and the resonance frequency adjustment is terminated.

When the reception voltage V1 is increasing, the loop of steps S16 → S17 → S14 → S15 → S16 is repeated. When the reception voltage V1 changes from rising to falling, the process exits the loop and proceeds from step S16 to step S19.

In the above case, the optimum resonance frequency value best_adj is given as the control signal SCON [2: 0] from the CPU 51 to the resonance frequency adjusting circuit 102, and the resonance frequency of the second resonance circuit R2 is optimized.

When the switch setting variable x and the switches SC0 to SC2 are turned on and off, and the values of the capacitors CC0 to CC2 are set as described above, the capacitance value of the resonance frequency adjusting circuit 102 is set to 0 pF by incrementing the switch setting variable x. From 1 to 7 pF, 1 pF is added. By sequentially adding the capacitance values, the resonance frequency of the second resonance circuit R2 is sequentially reduced. When the resonance frequency is sequentially lowered from a frequency higher than the carrier frequency of 13.56 MHz, the reception voltage V1 rises until the resonance frequency reaches 13.56 MHz, and reaches the peak at the resonance frequency of 13.56 MHz. Since the voltage V1 gradually decreases, the adjustment may be completed when the reception voltage V1 starts to decrease as shown in the flowchart of FIG. Note that the V1 voltage may be measured for all the switch setting variables x, and the switch setting variable x that maximizes the V1 voltage may be set as the optimum value.

The resonance frequency f0 is determined by the inductance L of the antenna coil and the capacitance C of the resonance capacitance, and is f0 = 1 / 2π√LC (the root sign √ is applied to the entire (LC)). In the NFC standard, since the frequency of the carrier wave is 13.56 MHz, the reception voltage becomes maximum when the resonance frequency f0 of the antenna resonance circuit is 13.56 MHz.

As described above, in the short-range wireless communication apparatus including the reader / writer function unit E1 and the non-contact IC card function unit E2, when the resonance frequency is automatically adjusted, the reader / writer function unit E1 and the non-contact IC card function unit E2 are provided. At the same time, the first antenna A1 and the second antenna A2 are electromagnetically coupled and the resonance frequency adjustment circuit 102 is also in the operation state, so that the external reader / writer device and measurement are performed. It is possible to automatically optimize the resonance frequency of the second antenna A2 without preparing a device and preparation work such as adjustment / calibration, and to reduce the cost of the short-range wireless communication device. Can do.

(Modification of the nineteenth embodiment)
Next, the specifications of the present embodiment relating to the resonance frequency automatic adjustment method that can cope with the change even if the specifications of the first antenna A1 and the second antenna A2 change variously and the reception state fluctuates as a result. A modification will be described. This modification corresponds to the above-described eighth embodiment.

The correspondence relationship with FIG. 4 in the case of the eighth embodiment will be described in advance. The output adjuster e13 corresponds to the driver 83, and the determiner e14 corresponds to the processing functions of steps S28 to S29 by the CPU 51. is doing.

FIG. 12 is a graph showing a difference in the state of the reception voltage V1 when adjusting the resonance frequency depending on the design (antenna size, number of turns, etc.) of the first antenna A1 and the second antenna A2. The horizontal axis is the switch setting variable x, and the vertical axis is the reception voltage V1.

In FIG. 12, the state A is a state in which the received voltage V1 differs depending on the switch setting variable x, and the peak voltage of V1 can be clearly detected (x = 5). In the state B, the coupling between the first antenna A1 and the second antenna A2 is strong, the reception voltage V1 becomes high, and some of the switch setting variables (x = 3 to 6) are set to the clamp voltage Vclamp by the shunt circuit 93. It is clamped and the peak voltage of V1 cannot be detected. In the state C, the coupling between the first antenna A1 and the second antenna A2 is weak, the reception voltage V1 is weak, the voltage difference due to the switch setting variable x is very small, and the peak voltage of V1 cannot be detected. is there.

As long as the result of the antenna design of the first antenna A1 and the second antenna A2 is the state A during the resonance frequency adjustment, there is no problem with the adjustment method shown in FIG. However, the shape and parameters of the first antenna A1 and the second antenna A2 may vary greatly depending on the space restrictions of the terminal to be mounted, the reader / writer output, and the required specifications of the card reception performance. As a result, the resonance frequency There is a possibility that a state B or a state C may be entered during adjustment.

In order to cope with such a situation where adjustment is difficult, the NFC-LSI 50 of FIG. 8 includes an output setting signal AJPW [1: 0] for changing the driver size in the driver 83. For example, when l (el) = 2, eight types of driver output sizes can be set by the output setting signal AJPW [2: 0]. If the output setting signal AJPW [2: 0] is replaced with a numerical value (0 to 7) as the driver output setting y, for example, the driver size of the driver 83 is increased in proportion to the value of the driver output size y. Set. The driver 83 corresponds to the output adjuster e13 of (8) described above. A part of the function of the CPU 51 corresponds to the determination device e14.

FIG. 13 is a flowchart of a resonance frequency adjusting method that can satisfactorily cope with the case where the specifications of the first antenna A1 and the second antenna A2 change variously and the reception state fluctuates as a result. Hereinafter, the operation will be described with reference to FIG.

First, resonance frequency adjustment is started in step S21, and then driver output setting y is initialized in step S22. At this time, the driver output setting y is set to a predetermined intermediate value among possible settings. For example, when y = 0 to 7, y = 4 is set.

Subsequently, in step S23, the carrier wave generation signal CAON = H is set, and an unmodulated magnetic field is output from the first antenna A1. Next, in step S24, the switch setting variable x = 1 and the V1 measurement results V1D (1) to V1D (m) = 0V are initialized.

After initialization, in step S25, the switch setting variable x is incremented by 1, and the resonance frequency of the second resonance circuit R2 is set via the resonance frequency adjustment circuit 102. In step S26, the generated voltage of the reception voltage V1 is set. Measurement is performed by the AD converter 95. The V1 voltage value VLV is stored in the V1 measurement result V1D (x).

Then, through step S27, the reception voltage V1 is measured while changing the resonance frequency until the switch setting variable x = 1 to x = m (= 8).

After obtaining the V1 measurement results V1D (1) to V1D (m) from the switch setting variable x = 1 to x = m, in step S28, the maximum of all the results of these V1D (1) to V1D (m) The value taking the value is set as the V1D maximum value V1D_max, and it is confirmed whether the V1D maximum value V1D_max is within a predetermined voltage range. In the predetermined range, as shown in FIG. 12, the upper limit value is a V1 upper limit value V1max that is a fixed voltage below the clamp reception voltage V1clamp, and the lower limit value is a V1 lower limit value V1min that enables peak discrimination.

If V1D_max is not within the range from the V1 lower limit value V1min to the V1 upper limit value V1max, the process proceeds to step S29 to determine whether the lower limit error is lower than the V1 lower limit value V1min or the upper limit error is higher than the V1 upper limit value V1max.

In the case of a lower limit error, the process proceeds to step S30, the driver output setting y is incremented by 1, and the process proceeds to step S24. V1 measurement results V1D (x) for all switch setting variables x are obtained again, and V1D maximum The range of the value V1D_max is confirmed.

If the upper limit error is determined in step S29, the process proceeds to step S31, the driver output setting y is decremented by 1, and the process proceeds to step S24. Similarly, the V1 measurement results V1D (for all switch setting variables x are again obtained. x) is acquired and the range of the V1D maximum value V1D_max is confirmed.

On the other hand, if it is determined in step S28 that the V1D maximum value V1D_max is within the range from the V1 lower limit value V1min to the V1 upper limit value V1max, the process proceeds to step S32 to set the switch that maximizes the V1 measurement result V1D (x). The variable x is stored in the resonance frequency optimum value best_adj, and the resonance frequency adjustment is finished.

When the received voltage V1 is not within the proper range, the loop of step S28 → S29 → S30 or S31 → S24 → S25 → S26 → S27 → S28 is repeated. When the reception voltage V1 changes from rising to falling, the process exits the loop and proceeds from step S28 to step S32.

By performing the above flow, the V1 measurement result V1D (x) in which the V1D maximum value V1D_max falls within the range from the V1 lower limit value V1min to the V1 upper limit value V1max can be acquired by any setting of the driver output setting y. (State A in FIG. 12), the optimum switch setting variable x can be stored in the optimum resonance frequency value best_adj.

According to the configuration of the short-range wireless communication device and the resonance frequency adjusting method described above, in addition to the effects of the first embodiment, the specifications of the first antenna A1 and the second antenna A2 change variously, and as a result, reception is performed. Even if the state fluctuates, the resonance frequency of the second antenna A2 can be adjusted reliably.

In the short-range wireless communication device of FIG. 8, the DC voltage of the reception voltage V1 output from the rectifier 91 is used as a criterion for determining the resonance frequency, but the current flowing through the shunt circuit 93 is used instead. It may also be possible (corresponding to the fifth embodiment).

In the resonance frequency automatic adjustment according to the flowcharts of FIGS. 10 and 13, the modulation circuit 82 outputs an unmodulated carrier wave. However, predetermined data for giving a certain degree of modulation is transmitted from the transmission signal TXRD to the modulation circuit 82. Is output, and a carrier wave modulated with a certain modulation degree is output, and a difference in fluctuation between the maximum value (no modulation) and the minimum value (during modulation) of the V1 voltage value VLV output from the AD converter 95 is measured. Then, the resonance frequency at which the variation difference of the reception voltage V1 is the largest may be adjusted as an optimum value (corresponding to the fourth embodiment).

Further, although not shown in the flowchart of FIG. 13, the driver output setting y is the maximum settable value (maximum output setting of the driver 83), and all of the V1 measurement results V1D (1) to V1D (m) at that time If the lower limit error is less than V1min, it is determined that the antenna connection is defective or the NFC-LSI 50 is faulty, and the adjustment failure result is output to the external I / F, or the adjustment error to the nonvolatile memory (NVM) 55 A flag or the like may be written and used for defect screening in the manufacturing process of the short-range wireless communication device.

(20th embodiment)
In this embodiment, the resonance frequency of the first resonance circuit R1 on the reader / writer function unit E1 side is automatically adjusted instead of the second resonance circuit R2 on the non-contact IC card function unit E2 side. The predetermined electrical information Si uses the reception voltage V1 at the non-contact IC card function unit E2.

FIG. 14 is a block diagram showing a configuration of the short-range wireless communication apparatus according to the present embodiment. The present embodiment corresponds to the first, third, eighth, eleventh, thirteenth, and fourteenth embodiments.

The present embodiment does not include the resonance frequency adjustment circuit 102 on the non-contact IC card function unit E2 side, but instead includes the resonance frequency adjustment circuit 101 on the reader / writer function unit E1 side. This is different from the short-range wireless communication apparatus of the embodiment. The resonance frequency adjustment circuit 101 is inserted between the first resonance circuit R1 and the reader / writer function unit E1. A signal for the CPU 51 to control the resonance frequency adjusting circuit 101 is SRON [n: 0]. Circuits other than the resonant frequency adjustment circuit 101 are the same as those in the nineteenth embodiment, and thus description thereof is omitted.

The resonance frequency adjusting circuit 101 includes a plurality of capacitors CR0 to CRn and a plurality of switches SR0 to SRn. Each pair of the capacitor CRn and the switch SRn is connected in series between the output signal TX and the reception signal RX so that the capacitor CRn is in parallel with the resonance capacitor 31. ON / OFF of the switches SR0 to SRn is controlled by a control signal SRON [n: 0] output from the CPU 51. The minimum value of n is 0. In this case, only CR0 and SR0 are obtained.

The operation of the automatic resonance frequency adjustment of the present embodiment corresponds to the switch setting variable x and the switch SCn in FIG. 11 and is the same as the flowchart in FIGS. 10 and 13 if the switch SCn is replaced with the switch SRn. The resonance frequency adjustment circuit 101 adjusts the resonance frequency of the first resonance circuit R1 to maximize the output of the first antenna A1, and as a result, the reception voltage V1 of the non-contact IC card function unit E2 is maximized. Control to become.

As described above, in the short-range wireless communication apparatus including the reader / writer function unit E1 and the non-contact IC card function unit E2, when the resonance frequency is automatically adjusted, the reader / writer function unit E1 and the non-contact IC card function unit E2 are provided. At the same time, the first antenna A1 and the second antenna A2 are electromagnetically coupled together and the resonance frequency adjustment circuit 101 is also in the operation state, so that an external non-contact IC card or The resonance frequency of the first antenna A1 can be automatically optimized without preparing a measurement device and preparation work such as adjustment / calibration, thereby reducing the cost of the short-range wireless communication device. be able to.

The NFC-LSI 50 in FIG. 14 does not include the resonance frequency adjustment circuit 102 for the second resonance circuit R2 in FIG. 8, but the NFC-LSI 50 in FIG. You may comprise so that the resonant frequency of both 1 resonance circuit R1 and 2nd resonance circuit R2 can be optimized. In this case, it is possible to optimize by eliminating the excess or deficiency of the transmission capability in the reader / writer function unit E1, and at the same time, it can eliminate and optimize the deficiency of the reception capability in the non-contact IC card function unit E2. Corresponding to the embodiment).

(Twenty-first embodiment)
In the present embodiment, the configuration is made so that the resonance frequency is adjusted through the right / wrong judgment of the transmitted / received data, so that the AD converter need not be mounted specially in the non-contact IC card function unit E2. .

In the present embodiment, the resonance frequency of the second resonance circuit R2 on the non-contact IC card function unit E2 side is automatically adjusted. As the predetermined electrical information Si, information utilizing the correctness determination of received data in the non-contact IC card function unit E2 is used. This embodiment corresponds to the sixth embodiment (see FIG. 3).

FIG. 15 is a block diagram showing the configuration of the short-range wireless communication apparatus of the present embodiment. The present embodiment corresponds to the first, sixth, seventh, eighth, eleventh, thirteenth, and fourteenth embodiments.

The short-range wireless communication apparatus according to the present embodiment transmits data from the first antenna A1 on the reader / writer function unit E1 side toward the second antenna A2 on the non-contact IC card function unit E2 side. And the point that the non-contact IC card function unit E2 is not provided with the AD converter 95 is different from the short-range wireless communication apparatus of the nineteenth embodiment. The short-range wireless communication apparatus according to the present embodiment transmits data from the reader / writer function unit E1 instead of using the reception voltage V1 of the non-contact IC card function unit E2 as in the nineteenth embodiment. The non-contact IC card function unit E2 receives the data, and automatically adjusts the optimum value of the resonance frequency through whether or not the transmitted data matches the received data, that is, whether the received data is correct or incorrect. Since other configurations are the same as those in the nineteenth embodiment, description thereof is omitted.

The operation of the automatic resonance frequency adjustment of the short-range wireless communication device of this embodiment will be described with reference to FIGS. FIG. 16 is a flowchart showing the operation of automatic resonance frequency adjustment. FIG. 17 is a table showing examples of correct / incorrect results of received data.

In the flowchart of FIG. 16, description of parts that perform the same operations as the flowchart of FIG. 13 of the nineteenth embodiment, such as the output setting of the driver 83 and the resonance frequency setting of the resonance frequency adjusting circuit 102, will be simplified.

First, resonance frequency adjustment is started in step S41, then driver output setting y is initialized to an intermediate value in step S42, and the carrier wave generation signal CAON = H is set in step S43 to turn on the magnetic field. Next, in step S44, the switch setting variable x = 1 is initialized, and the variable for storing the correct / incorrect result of the received data, the data correct / incorrect result D (x), D (1) to D (m) = NG Initialize to. After initialization, the switch setting variable x is incremented by 1 in step S45, and predetermined check data is output from the reader / writer function unit E1 in step S46. Specifically, the CPU 51 outputs predetermined check data to the TXRD, outputs a modulation signal S1 ASK-modulated by the modulation circuit 82 with a predetermined modulation degree, and the driver 83 transmits the transmission signal TX to the first antenna A1. Send.

Next, in step S47, the transmitted check data is received by the non-contact IC card function unit E2 by electromagnetic induction of the first antenna A1 and the second antenna A2. Specifically, the ASK-modulated carrier wave is rectified by the rectifier 91, and the voltage fluctuation of the rectified reception voltage V <b> 1 is demodulated into a digital reception data signal RXCD by the demodulation circuit 92 and input to the CPU 51. The feature of the third embodiment is that the demodulation circuit 92 is utilized.

The CPU 51 checks whether or not the predetermined check data transmitted from the reader / writer function unit E1 matches the data received by the non-contact IC card function unit E2, and determines whether the data is OK (match) or NG (not match). Store in correct / wrong result D (x).

Then, through step S48, the transmission / reception of the check data and the correctness / incorrectness determination are performed while changing the resonance frequency until the switch setting variable x = 1 to x = m.

After acquiring the data correct / incorrect results D (1) to D (m) from the switch setting variable x = 1 to x = m, it is checked in step S49 whether all of these results are NG or all are OK.

Here, in order to facilitate understanding, an example of the operation will be described with reference to FIG. 17 (in the case of m = 8). If all of the data correct / incorrect results D (1) to D (8) are NG, the result is C, and if all are OK, the result is B.

When the result C when all are NG is detected, the output is increased. As a result, for example, as shown in the result A of FIG. 17, D (1), D (5) to D (8) remain NG, and D (2), D (3), D (4) Suppose that is OK. In D (1) and D (5) to D (8), the resonance frequency is still insufficiently set and the reception voltage V1 having sufficient signal strength is not obtained. However, as a result of increasing the output, In D (2) to D (4), the setting of the resonance frequency is good, which means that the reception voltage V1 having the signal strength necessary for the demodulation of the demodulation circuit 92 is obtained. If any of the data correct / incorrect results D (1) to D (8) is changed from NG to any OK result, it means that all of the data correct / incorrect results D (1) to D (8) are NG. Or all are not OK. Which of the switch setting variable x causes the data correct / incorrect result to turn into various changes. Further, the number of switch setting variables x when the data correct / incorrect result is changed to OK changes variously. The result A shown in FIG. 17 is only an example.

Conversely, when the result B is detected when everything is OK, the output is lowered. As a result, for example, as shown in the result A of FIG. 17, D (1), D (5) to D (8) remain NG, and D (2), D (3), D (4) Suppose that is OK. If any of the data correct / incorrect results D (1) to D (8) is OK from any of the data correct / incorrect results D (1) to D (8), it means that all of the data correct / incorrect results D (1) to D (8) are NG. Or all are not OK. Which of the switch setting variable x causes the data correct / incorrect result to turn to NG varies in various ways. Further, the number of switch setting variables x when the data correct / incorrect result is changed to NG also changes variously. The result A shown in FIG. 17 is only an example.

In any case, when all of the data correct / incorrect results D (1) to D (8) change from the NG state or the all OK state to the other state, the process of increasing the output or the process of decreasing the output is performed. Finish. With this, the conditions for obtaining the optimal solution are met. If the determination in the first step S49 is No, it means that the conditions for obtaining the optimum solution are complete, and the process for increasing the output or the process for decreasing the output may not be performed.

The explanation of the operation example is completed, and then the flowchart of FIG. 16 is explained. If all the data correct / incorrect results D (1) to D (m) are NG, the process proceeds to step S50, and the received voltage V1 is insufficient, so the process further proceeds to step S51 to increment the driver output setting y by 1, In S44, data correct / incorrect results D (x) for all switch setting variables x are acquired again, and the results of data correct / incorrect results D (1) to D (m) are confirmed.

If all the data correct / incorrect results D (1) to D (m) are OK, the process proceeds to step S50, and the received voltage V1 is sufficient for all the switch setting variables x. y is decremented by 1, and the process proceeds to step S44. The data correct / incorrect results D (x) for all the switch setting variables x are obtained again, and the results of the data correct / incorrect results D (1) to D (m) are confirmed. .

If all of the data correct / incorrect results D (1) to D (m) are NG or not all determined in step S49, the process proceeds to step S53, and the intermediate value in the range of x where D (x) = OK. Is stored in the resonance frequency optimum value best_adj, and the resonance frequency adjustment is finished.

When all of the data correct / incorrect results D (1) to D (m) are NG or all are OK (no change), step S49 → S50 → S51 or S52 → S44 → S45 → S46 → S47 → S48 → The loop of S49 is repeated. Repeat one or more times. When all of the data correct / incorrect results D (1) to D (m) are NG or all are not OK (when a characteristic appears in the change), the process goes out of the loop and proceeds from step S49 to step S53.

When all of the data correct / incorrect results D (1) to D (m) are NG or all are not OK and one of them is OK and one of them is NG, the data correct / incorrect result D corresponding to the state transition The number of (i) varies variously. When the number is an odd number, the median is adopted as the intermediate value. When the number is three, the second one is adopted, when the number is five, the third one is adopted, and when the number is seven, the fifth one is adopted. When the number is even, either one of the two located in the center is adopted.

In the example of the result A in FIG. 17, D (2) = OK when x = 2, D (3) = OK when x = 3, D (4) = OK when x = 4, and others. Is NG, an intermediate value of x = 2, 3, and 4 is taken, and x = 3 is stored in the resonance frequency optimum value best_adj. The reason why the intermediate value in the range of x where D (x) = OK is set is that this state is the state where the reception voltage V1 is the highest.

As another example, if D (3) = OK, D (4) = OK, D (5) = OK and the others are NG, x = 4 is stored in best_adj.

For example, if D (3) = OK, D (4) = OK, D (5) = OK, D (6) = OK, D (7) = OK, and the others are NG, x = 5 Is stored in best_adj.

Also, for example, if only one D (6) = OK and the others are NG, x = 6 is stored in best_adj.

By performing the above flow, the data correct / incorrect result D (x) including both OK and NG results can be acquired with any setting of the driver output setting y, and the optimum switch setting variable x is set. The resonance frequency optimum value best_adj can be stored.

According to the configuration of the short-range wireless communication device of the present embodiment, the second antenna A2 can be automatically and only the own device without using an external reader / writer device or measurement device. It is possible to optimize the resonance frequency. Moreover, even if the specifications of the first antenna A1 and the second antenna A2 change variously and the reception state fluctuates as a result, the resonance frequency of the second antenna A2 can be reliably adjusted.

Further, the short-range wireless communication apparatus of the present embodiment uses the demodulation circuit 92 inherently possessed by the non-contact IC card function unit E2, and receives the received data signal RXCD as a result of demodulation by the demodulation circuit 92. It is characterized in that it is used as predetermined electrical information SiＳ. As a result, the AD converter 95 required in the case of the first embodiment determined by measuring the output voltage V1 of the rectifier 91 becomes unnecessary. That is, resonance characteristic adjustment can be realized with a smaller circuit configuration, and the cost can be further suppressed.

In the above description, when checking whether the check data received by the non-contact IC card function unit E2 is correct or incorrect, the comparison with the data transmitted by the reader / writer function unit E1 is performed. Therefore, the parity included in the check data and CRC (Cyclic Redundancy Check) It is possible to check more reliably than in the case of checking using. However, the present invention can include the case of checking using parity or CRC instead of matching comparison when determining the correctness of check data.

Further, when the reader / writer function unit E1 transmits, for example, a request command REQB of ISO / IEC14443TypeB, and it is determined based on the presence / absence of a response ATQB from the non-contact IC card function unit E2 (command transmission and response reception), it is assumed that NFC -Even if another non-contact IC card exists in the vicinity of the LSI 50, the second antenna A2 of the NFC-LSI 50 itself is surely set in order to discriminate by the received data of the non-contact IC card function unit E2 of the same NFC-LSI 50. Can be adjusted. However, the present invention may include a case of checking using command transmission and presence / absence of response instead of matching comparison when determining whether the check data is correct or incorrect.

In the above description, the modulation degree of the ASK modulation of the modulation circuit 82 and the protocol to be used at the time of automatically adjusting the resonance frequency are not specified. However, for example, ISO is not an ASK100% system such as ISO / IEC14443TypeA, but ISO A protocol of about 10% ASK such as / IEC14443TypeB or JISX6319-4 is suitable for the resonance frequency adjustment method of the third embodiment because the signal strength of the reception voltage V1 is weaker and the conditions are severer with respect to the demodulation circuit 92. .

Further, the modulation circuit 82 may further include a mechanism capable of finely adjusting the modulation degree of ASK, and a modulation degree different from that during normal use may be used during automatic adjustment of the resonance frequency. For example, when the resonance frequency is automatically adjusted, even if ISO / IEC14443 Type B is used as a protocol, the resonance frequency is set to a severe condition such as ASK 5% instead of ASK 10% of the typical condition used in the reader mode of the normal NFC. Automatic adjustment may be performed. This corresponds to the above-described modulation degree adjuster e15 of (9) (see FIG. 5).

Further, instead of finely adjusting the modulation degree of the modulation circuit 82, the demodulation sensitivity of the demodulation circuit 92 may be finely adjusted (corresponding to the above tenth embodiment, see FIG. 6), and further the modulation circuit Both the modulation degree 82 and the demodulation sensitivity of the demodulation circuit 92 may be finely adjusted.

Although not shown in the flowchart of FIG. 16, the driver output setting y is the maximum settable value (maximum output setting of the driver 83), and all the data correct / incorrect results D (1) to D (m) at that time are If it becomes NG, it is determined that the antenna connection is defective or the NFC-LSI 1 is defective, and the adjustment failure result is output to the external I / F, or the adjustment failure flag is written in the nonvolatile memory (NVM) 55, You may use for the defect screening of the manufacturing process of a near field communication apparatus.

(Twenty-second embodiment)
The short-range wireless communication apparatus according to the present embodiment relates to automatic adjustment of the resonance frequency of the resonance circuit of the first antenna (reader / writer antenna) of the NFC-LSI 50. The resonance frequency is adjusted by determining whether the received data of the non-contact IC card function unit is correct or incorrect.

FIG. 18 is a block diagram showing a configuration of the short-range wireless communication apparatus according to the present embodiment. The present embodiment also corresponds to the first, sixth, seventh, eighth, eleventh, thirteenth, fourteenth, and fifteenth embodiments, as in the twenty-first embodiment.

The short-range wireless communication apparatus of this embodiment is different from the short-range wireless communication apparatus of the twentieth embodiment in that the AD converter 95 is not provided. The short-range wireless communication apparatus according to the present embodiment does not include the resonance frequency adjustment circuit 102 of the non-contact IC card function unit E2, but instead includes the resonance frequency adjustment circuit 101 in the reader / writer function unit E1. This is different from the short-range wireless communication apparatus of the nineteenth embodiment. The configuration of the resonance frequency adjustment circuit 101 is the same as that of the short-range wireless communication apparatus according to the twentieth embodiment shown in FIG.

The resonance frequency automatic adjustment operation of the present embodiment corresponds to the switch setting variable x in FIG. 11 and the switch SCn, and is the same as the flowchart in FIG. 16 if the switch SCn is replaced with the switch SRn. Adjusts the resonance frequency of the first resonance circuit R1 to maximize the output of the first antenna A1, and as a result, the intermediate value of the switch setting variable x for which the data correct / incorrect result D (x) is OK. That is, control is performed so that the reception voltage V1 is maximized.

According to the configuration of the short-range wireless communication apparatus as described above, it is possible to automatically optimize the resonance frequency of the first antenna A1 without using an external non-contact IC card or a measurement apparatus. Moreover, even if the specifications of the first antenna A1 and the second antenna A2 change variously and the reception state fluctuates as a result, the resonance frequency of the first antenna A1 can be adjusted reliably.

The NFC-LSI 50 of FIG. 18 does not include the resonance frequency adjustment circuit 102 of the second antenna A2 of FIG. 15. However, the NFC-LSI 50 of FIG. The antenna A1 and the second antenna A2 may be configured to be optimized.

Further, through the nineteenth to twenty-second embodiments, the resonance frequency of the antenna is adjusted by increasing / decreasing the capacity of the resonance circuit. Alternatively, the resonance frequency may be adjusted by increasing / decreasing the inductance. Instead of adjusting the resonance frequency of the resonance circuit, the quality factor (Q value) may be adjusted by increasing or decreasing the resistance of the resonance circuit.

Through the nineteenth to twenty-second embodiments, this resonance frequency automatic adjustment is performed only at the time of product manufacture, and the adjustment results obtained at the time of manufacture (states of switches SC0 to SCn, SR0 to SRn) are nonvolatile. The data stored in the memory (NVM) 55 may be configured to read and set data stored in the nonvolatile memory (NVM) 55 during normal operation. Conversely, this automatic resonance frequency automatic adjustment may be configured such that the resonance frequency automatic adjustment is performed every time, for example, at the start-up after the power switch is turned on, even after the mounted product (for example, a mobile phone) is shipped. In this case, each time the use is started, the resonance frequency can be optimized in accordance with the use environment including the temperature condition and the like, so that the communication distance of the short-range wireless communication device can be further optimized.

Further, through the nineteenth to twenty-second embodiments, the NFC-LSI 50 has a configuration in which a CPU 51, a ROM 53, and a RAM 54 are mounted, and a program for automatic resonance frequency adjustment is stored in the ROM 53. You may comprise all with a logic circuit, without using. Therefore, the NFC-LSI 50 may be configured without a CPU, ROM, or RAM.

The short-range wireless communication device of the present invention is not limited to the mobile phone shown in FIG. 7, but a wide variety of devices such as reader / writer devices, personal computers, various AV (Audio and Visual) devices, various portable devices, card media, and the like. Can be applied to products.

In addition, although several embodiment was demonstrated in the above, you may combine each component in a some Example arbitrarily in the range which does not deviate from the meaning of this invention.

The present invention provides a device (reader) different from a short-range wireless communication device when adjusting resonance characteristics such as a resonance frequency in a short-range wireless communication device including a reader / writer function unit and a non-contact IC card function unit. It is an excellent technology that enables the adjustment to be completed only by the short-range wireless communication device without the need for a writer device or a contactless IC card reference card, and in particular, corresponds to the NFC standard. It is useful as a non-contact communication device.

A1 First antenna (reader / writer antenna)
A2 Second antenna (card antenna)
CCn, CRn Capacitance E1 Reader / Writer Function Unit E2 Contactless IC Card Function Unit E3 Resonant Circuit Adjustment Unit R1 First Resonant Circuit R2 Second Resonant Circuit SCn, SRn Switch Son Predetermined Start Signal Sac AC Signal Si Predetermined Electrical Information e11 Modulator circuit e12 Demodulator circuit e13 Output adjuster e14 Judger e15 Modulation degree adjuster e21 Rectifier e22 Demodulator circuit e23 Load modulator e24 AD converter e25 Shunt circuit e26 Demodulation sensitivity adjuster e27 Judger 1 Mobile phone 2 Contactless IC Card reader / writer 3

Non-contact IC card

31, 41 Resonant capacity 50 NFC-LSI
51 CPU
52 I / F
53 ROM
54 RAM
55 Nonvolatile memory (NVM)
60 UICC
70 Application Processor 81 Carrier Wave Generation Circuit 82 Modulation Circuit 83 Driver (Output Regulator)
84 Demodulation circuit 91 Rectifier 93 Shunt circuit 94 Load switch 95 AD converter (ADC)
101, 102 Resonance frequency adjustment circuit (example of resonance circuit adjustment unit)

Claims

A first resonant circuit including a first antenna;
A reader / writer function unit that generates an AC signal having a predetermined output in response to a predetermined activation signal and supplies the AC signal to the first resonance circuit;
A second resonant circuit including a second antenna and tuned to the first resonant circuit via electromagnetic induction between the first antenna and the second antenna;
A non-contact IC card function unit that generates predetermined electrical information by tuning the second resonant circuit;
A resonance circuit adjustment unit that adjusts resonance characteristics of the first resonance circuit or the second resonance circuit based on predetermined electrical information generated in the non-contact IC card function unit;
A short-range wireless communication device.
The resonance circuit adjustment unit is configured to adjust resonance characteristics of both the first resonance circuit and the second resonance circuit based on predetermined electrical information generated in the non-contact IC card function unit. Being
The near field communication apparatus according to claim 1.
The reader / writer function unit is configured to generate an unmodulated constant-current AC signal as the predetermined output AC signal,
The non-contact IC card function unit includes an AD converter connected to a rectifier connected to the second resonance circuit, and a voltage appearing on an output side of the rectifier is used as the predetermined electrical information as the AD converter. Use the digitally converted
The near field communication apparatus according to claim 1.
The reader / writer function unit is configured such that a built-in modulation circuit generates a signal obtained by amplitude-modulating a carrier wave with a constant modulation degree as an AC signal of the predetermined output,
The non-contact IC card function unit includes an AD converter connected to a rectifier connected to the second resonance circuit, and the difference between voltage fluctuations appearing on the output side of the rectifier as the predetermined electrical information. Use what was digitally converted by the AD converter,
The near field communication apparatus according to claim 1.
The reader / writer function unit is configured to generate an unmodulated constant-current AC signal as the predetermined output AC signal,
The non-contact IC card function unit includes a shunt circuit and an AD converter connected to a rectifier connected to the second resonance circuit, and a shunt current flowing through the shunt circuit as the predetermined electrical information is the AD Use what was digitally converted by a converter,
The near field communication apparatus according to claim 1.
The reader / writer function unit is configured so that a built-in modulation circuit generates a signal obtained by modulating a carrier wave with predetermined transmission data as an AC signal of the predetermined output,
The non-contact IC card function unit uses reception data corresponding to the transmission data appearing in a built-in demodulation circuit as the predetermined electrical information.
The near field communication apparatus according to claim 1.
The resonance circuit adjustment unit is configured to execute the adjustment process of the resonance characteristic through determination of coincidence / mismatch with the transmission data for the reception data in the non-contact IC card function unit.
The short-range wireless communication apparatus according to claim 6.
The reader / writer function unit
An output adjuster for adjusting the intensity of the AC signal of the predetermined output;
A determiner that determines a setting of the output regulator based on the predetermined electrical information;
Further equipped with,
The near field communication apparatus according to claim 1.
The reader / writer function unit
A modulation degree adjuster that adjusts the modulation degree of the AC signal of the predetermined output;
A determiner that determines a setting of the modulation factor adjuster based on the predetermined electrical information;
Further equipped with,
The near field communication apparatus according to claim 1.
The non-contact IC card function unit is:
A demodulation sensitivity adjuster for adjusting the demodulation sensitivity of the demodulation circuit;
A determiner that determines a setting of the demodulation sensitivity adjuster based on the predetermined electrical information;
Further equipped with,
The near field communication apparatus according to claim 1.
The reader / writer function unit uses a startup signal of the short-range wireless communication device as the predetermined startup signal.
The near field communication apparatus according to claim 1.
The resonance characteristic to be adjusted is a resonance frequency, a quality factor (Q value), or both a resonance frequency and a quality factor (Q value).
The near field communication apparatus according to claim 1.
The short-range wireless communication apparatus according to claim 1,
The short-range wireless communication device is configured such that at least the reader / writer function unit, the contactless IC card function unit, and the resonance circuit adjustment unit are integrated on a semiconductor.
Semiconductor integrated circuit for near field communication.
The reader / writer function unit has a connection terminal of the first resonance circuit, and the non-contact IC card function unit has a connection terminal of the second resonance circuit,
14. The semiconductor integrated circuit for near field communication according to claim 13.
The main part or all of the first resonance circuit and the second resonance circuit are provided on the semiconductor.
14. The semiconductor integrated circuit for near field communication according to claim 13.
The first resonant circuit includes the first antenna;
The second resonant circuit includes the second antenna;
16. The semiconductor integrated circuit for near field communication according to claim 15.
The first resonant circuit includes a resonant capacitor;
The second resonant circuit includes a resonant capacitance;
16. The semiconductor integrated circuit for near field communication according to claim 15.
The first resonant circuit includes the first antenna and a resonant capacitor;
The second resonant circuit includes the second antenna and a resonant capacitor;
16. The semiconductor integrated circuit for near field communication according to claim 15.