JP7264777B2 - Wireless device, self-diagnostic method and program for wireless device - Google Patents

Description

The present invention relates to a wireless device, a self-diagnostic method and program for the wireless device.

In recent years, short-range wireless device communication techniques such as RFID tag reader/writer devices using RFID (Radio Frequency Identifier) have been used as wireless devices. A conventional RFID tag reader/writer device radiates a transmission signal generated in a transmission circuit from an antenna into the air. Then, the RFID tag reader/writer device receives a response signal returned from the tag in response to the radiated signal with the antenna, amplifies and demodulates with the receiving circuit, and receives the response of the tag.

As such an RFID tag reader/writer device, there has been proposed a technology capable of receiving a signal returned from a tag by a quadrature detection circuit (see, for example, Patent Document 1).

JP 2009-130604 A

However, in the conventional RFID tag reader/writer device, it is possible to diagnose whether the signal cannot be transmitted to the antenna due to an abnormality in the transmission circuit, whether the signal cannot be received due to an abnormality in the tag, or whether the signal cannot be received due to an abnormality in the receiving circuit. I couldn't. Further, when diagnosing an abnormal portion by an external device, there is a possibility that the circuit scale becomes large and the cost increases.

An object of one aspect of the present invention is to provide a wireless device capable of diagnosing whether there is an abnormality in the wireless device without using an external device.

A wireless device according to one aspect of the present invention includes a transmission circuit that transmits a test signal to an antenna, a reception circuit that receives the test signal transmitted from the transmission circuit in the same frequency band as the transmission circuit, and the transmission a control unit that diagnoses based on the test signal transmitted from the circuit and the test signal received by the receiving circuit, wherein the control unit detects the test signal that has leaked into the receiving circuit; A wireless device for diagnosing the presence or absence of an abnormality in the wireless device by determining , divides the received signal into two signals, outputs the divided signals to the I-ch reception mixer and the Q-ch reception mixer, respectively , and the transmission circuit divides the test signal transmitted from the transmission circuit. further comprising a phase shifter that adjusts the phase, wherein the control unit diagnoses the operation of the receiving circuit composed of a quadrature demodulation circuit by adjusting the phase of the test signal with the phase shifter; A wireless device characterized by:

A self-diagnostic method for a wireless device according to one aspect of the present invention includes adjusting the phase of a test signal to be transmitted , transmitting the test signal to an antenna, determining the test signal that leaked into a receiving circuit based on the test signal received and transmitted to the antenna and the received test signal, wherein the adjustment of the phase: A self-diagnostic method for a wireless device for diagnosing whether there is an abnormality in the wireless device by diagnosing the operation of the receiver circuit configured by a quadrature demodulation circuit , wherein the receiver circuit comprises a distributor and an I-ch. A receive mixer and a Q-ch receive mixer, wherein the distributor divides the received signal into two signals and outputs the divided signals to the I-ch receive mixer and the Q-ch receive mixer, respectively. A self-diagnostic method characterized by:

A program according to one aspect of the present invention includes a process of adjusting the phase of a transmitted test signal and transmitting the test signal to an antenna, and a process of receiving in the same frequency band as the test signal transmitted to the antenna. and determining the test signal leaking into a receiving circuit based on the test signal transmitted to the antenna and the received test signal , wherein the adjustment of the phase results in quadrature A program for diagnosing the presence or absence of an abnormality in the wireless device by diagnosing the operation of the receiving circuit composed of a demodulation circuit , wherein the receiving circuit is a distributor and an I-ch receiver. A mixer and a Q-ch receive mixer, wherein the distributor divides a received signal into two signals and outputs the divided signals to the I-ch receive mixer and the Q-ch receive mixer, respectively. A program characterized by:

According to the above-described aspect, it is possible to provide a wireless device capable of diagnosing whether there is an abnormality in the wireless device without using an external device.

1 is a diagram showing an example of an RFID tag reader/writer system 1 of this embodiment; FIG. 1 is a circuit diagram showing an example of an RFID tag reader/writer device 10; FIG. It is a figure which shows an example of a structure of the coupler of this embodiment. 4 is a flowchart showing an example of self-diagnostic processing according to the embodiment;

FIG. 1 is a diagram showing an example of an RFID tag reader/writer system 1 of this embodiment. The RFID tag reader/writer system 1 includes an RFID tag reader/writer device 10 and a plurality of RFID tags 101 attached to a plurality of articles 100 . The RFID tag reader/writer device 10 is an example of a wireless device. In this embodiment, the RFID tag 101 attached to the article 100 is conveyed on the belt conveyor 200 in the conveying direction (rightward in FIG. 1).

The RFID tag 101 is an identification tag attached to an article 100 to be identified and managed, and includes an antenna 101a. The antenna 101a is formed so as to match the frequency of the transmission signal transmitted from the RFID tag reader/writer device 10, and is, for example, a dipole antenna made of an aluminum foil antenna pattern. The RFID tag 101 receives a transmission signal transmitted from the RFID tag reader/writer device 10 and returns a response signal to the RFID tag reader/writer device 10 by a backscatter method. Then, the RFID tag reader/writer device 10 receives and demodulates the response signal from the RFID tag 101 to communicate information with the RFID tag 101 . The RFID tag reader/writer device 10 according to the present embodiment performs reading operation of the RFID tag 101 based on instructions from a PC (Personal Computer) 300, for example.

FIG. 2 is a circuit diagram showing an example of the RFID tag reader/writer device 10. As shown in FIG.
The RFID tag reader/writer device 10 includes a CPU (Central Processing Unit) 20 for overall control, a storage unit 21, a transmission circuit 30, a first power detector 37, a local oscillator 40, a second coupler 50, a matching adjuster 51, a second It has a three-coupler 60 , a second power detector 61 , a switching circuit 70 , an antenna 80 , an antenna terminal 81 and a receiving circuit 90 .

The CPU 20 controls the entire RFID tag reader/writer device 10 . Based on the programs stored in the storage unit 21, the CPU 20 performs various controls described below and self-diagnosis processing described later. The CPU 20 is an example of a control section. The storage unit 21 stores various data necessary for processing by the CPU 20, programs to be executed by the CPU 20, application programs, and the like. The RFID tag reader/writer device 10 has computer functions, and executes self-diagnostic processing, which will be described later, according to a self-diagnostic processing program. The RFID tag reader/writer device 10 may have a circuit configuration not shown in FIG. 2, such as a communication circuit for communicating with the PC 300, for example. Although the antenna 80 is a circuit forming part of the RFID tag reader/writer device 10 , it is not limited to this, and may have a different circuit configuration from that of the RFID tag reader/writer device 10 .

When the RFID tag reader/writer device 10 receives an instruction to issue a read command from the PC 300 , the CPU 20 analyzes the command and outputs a transmission signal, which is an instruction to issue a read command, to the transmission circuit 30 . Further, the CPU 20 transmits a predetermined test pattern signal to the transmission circuit 30 during self-diagnosis processing. As the test pattern signal, any rectangular wave (square wave) signal, a signal simulating a response signal of a tag, a known pattern signal, or the like can be adopted. A test pattern signal is an example of a test signal.

The local oscillator 40 outputs a local oscillator signal with a predetermined oscillation frequency.
The transmission circuit 30 has a DAC (Digital to analog converter) 31 , a transmission baseband processing circuit 32 , a transmission mixer 33 , a first transmission amplifier 34 , a first coupler 35 and a phase shifter 36 . The transmission circuit 30 may have a circuit configuration not shown in FIG. Hereinafter, the circuit configuration within the transmission circuit 30 may be referred to as a "transmission system".

The DAC 31 converts the digital transmission signal generated by the CPU 20 into an analog signal and outputs it to the transmission baseband processing circuit 32 .

The transmission baseband processing circuit 32 performs waveform shaping processing such as processing for removing unnecessary frequency components from the transmission signal output from the DAC 31 .

The transmission mixer 33 multiplies the transmission signal waveform-shaped by the transmission baseband processing circuit 32 by the local oscillator signal output from the local oscillator 40 . As a result, the transmission signal is upconverted to the frequency of the local oscillator signal output from the local oscillator 40 .

The first transmission amplifier 34 amplifies the up-converted transmission signal to a predetermined transmission power and outputs it to the first coupler 35 . The first coupler 35 outputs the transmission signal amplified by the first transmission amplifier 34 to the phase shifter 36 and also transmits part of the transmission signal (power) to the first power detector 37 .

FIG. 3 is a diagram showing an example of the configuration of the coupler of this embodiment. FIG. 3(1) is a diagram showing an example of the configuration of the first coupler 35. As shown in FIG. The first coupler 35 includes, as input/output terminals, a first terminal (Input) P1, a second terminal (Direct) P2, a third terminal (Isolated) P3, and a fourth terminal (Coupled) P4.

In the first coupler 35, the signal output from the first transmission amplifier 34 is input to the first terminal P1. The second terminal P2 outputs the signal input to the first terminal P1 to the phase shifter . Since the third terminal P3 is not used in the first coupler 35, it is connected to a terminating resistor (eg, 50Ω). The fourth terminal P4 is configured as a coupling output terminal, and part of the signal (power) input to the first terminal P1 is transmitted to the first power detector 37. The first power detector 37 detects a voltage converted from the power of the signal transmitted from the first coupler 35 as power. Although the first power detector 37 is configured as a circuit configuration different from that of the transmission circuit 30 , it is not limited to this, and may be configured as one circuit that configures the transmission circuit 30 .

A case where a signal of "+30 dBm" is input to the first terminal P1 of the first coupler 35 as the output of the first transmission amplifier 34 will be described below. In this case, the second terminal P2 outputs a signal that is reduced by the insertion loss of the first coupler 35 from the output of the transmission amplifier "+30 dBm" (input to the first terminal P1). The insertion loss of the first coupler 35 is defined in advance as a specification for each frequency band of each coupler. In this embodiment, it is assumed that the insertion loss of the first coupler 35 is "0.2 dB" at 920 MHz. Therefore, a signal of "30-0.2=29.8 dBm" is output from the second terminal P2. The signal output from the second terminal P2 is attenuated only by about "(10^(30/10)-10^(29.8/10))÷10^(30/10)×100=4.5%". Therefore, even when the first coupler 35 is connected, the RFID tag reader/writer device 10 can be diagnosed with almost no effect on the transmission/reception performance of the RFID tag reader/writer device 10 .

The amount of coupling (coupling amount) of the first coupler 35 is defined in advance as a specification for each frequency band of each coupler. In this embodiment, the coupling amount of the first coupler 35 is assumed to be "10 dB" at 920 MHz. Therefore, a signal of "30-10=20 dBm" is output to the first power detector 37 from the fourth terminal P4. Therefore, the first power detector 37 connected to the fourth terminal P4 can detect a signal power of "20 dBm" in normal operation.

Information indicating the power “20 dBm” that can be detected by the first power detector 37 in a normal state is stored in the storage unit 21 in advance. Therefore, the CPU 20 determines whether or not the power detected by the first power detector 37 is within the expected range of power (electric power) that can be detected in a normal state. It is possible to diagnose whether or not there is an abnormality in the range of . As the expected range, for example, an error range of power that can be detected by the first power detector 37 in a normal state can be set.

When diagnosing that there is an abnormality in the range from the DAC 31 of the transmission system to the first transmission amplifier 34, the CPU 20 notifies an upper device such as the PC 300 or a server (not shown) of the abnormality. As the contents of the notification, for example, a message to the effect that there is an abnormality in the range from the DAC 31 of the transmission system to the first transmission amplifier 34 can be displayed on the display or notified by the speaker. The administrator of the RFID tag reader/writer device 10 who receives this notification can quickly identify the location of the abnormality.

The CPU 20 adjusts the phase control amount θ of the transmission signal (test pattern signal) output from the first coupler 35 so that the amplitude of the received signal in the I-ch or Q-ch configured by the quadrature demodulation circuit is Adjust the phase shifter 36 to the maximum phase. The details of the method of diagnosing the operation of the I-ch and Q-ch receiving circuits 90 constituting the quadrature demodulation circuit by the CPU 20 based on the phase-adjusted received signals will be described later. Phase shifter 36 outputs the phase-adjusted transmission signal to second coupler 50 .

FIG. 3(2) is a diagram showing an example of the configuration of the second coupler 50. As shown in FIG. Since the configuration of the second coupler 50 is substantially the same as the configuration of the first coupler 35 in FIG. 3(1), redundant description is omitted by using the same reference numerals.

In the second coupler 50, the signal output from the transmission circuit 30 is input to the first terminal P1. The second terminal P2 outputs the signal input to the first terminal P1 to the third coupler 60 . A reflected signal from the antenna 80 is input to the second terminal P2 via the antenna terminal 81, the switching circuit 70, and the third coupler 60. As shown in FIG. A third terminal P3 is connected to the matching adjuster 51 . The fourth terminal P4 outputs to the receiving circuit 90 the signal input from the second terminal P2 and the signal leaked from the transmitting circuit 30 through the first terminal P1.

The matching regulator 51 is a terminating circuit connected to the third terminal P3 of the second coupler 50 . The matching adjuster 51 is a terminating resistor or the like of the second coupler 50 connected between the third terminal P3 of the second coupler 50 and ground. Under the control of the CPU 20, the matching adjuster 51 adjusts signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90, which has flowed through the first terminal P1 to the fourth terminal P4. The matching adjuster 51 is configured to be able to adjust the capacitance component (C), the inductance component (L), and the like. Details of a method for adjusting signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 by the matching adjuster 51 will be described later.

FIG. 3(3) is a diagram showing an example of the configuration of the third coupler 60. As shown in FIG. Since the configuration of the third coupler 60 is substantially the same as the configuration of the first coupler 35 in FIG. 3(1), redundant description is omitted by using the same reference numerals.

In the third coupler 60, the signal output from the second coupler 50 is input to the first terminal P1. The second terminal P2 outputs the signal input to the first terminal P1 to the switching circuit 70 . A reflected signal from the antenna 80 is input to the second terminal P2 via the antenna terminal 81 and the switching circuit 70. FIG. Since the third terminal P3 is not used in the third coupler 60, it is connected to a terminating resistor (eg, 50Ω). The fourth terminal P4 is configured as a coupling output terminal, and part of the signal (power) input to the first terminal P1 is transmitted to the second power detector 61. The second power detector 61 detects a voltage converted from the power of the signal transmitted from the third coupler 60 as power.

Information indicating the power (dBm) that can be detected by the second power detector 61 in a normal state is stored in the storage unit 21 in advance. Therefore, the CPU 20 determines whether or not the power detected by the second power detector 61 is within the expected range of power (electric power) that can be detected in a normal state. It is possible to diagnose whether there is an abnormality in the range up to 50. As the expected range, for example, an error range of power that can be detected by the second power detector 61 in a normal state can be set.

When diagnosing that there is an abnormality in the range from the first coupler 35 to the second coupler 50 of the transmission system, the CPU 20 notifies an upper device such as the PC 300 or a server (not shown) of the abnormality. As the content of the notification, for example, a message indicating that there is an abnormality in the range from the first coupler 35 to the second coupler 50 of the transmission system can be displayed on the display or notified by the speaker. The administrator of the RFID tag reader/writer device 10 who receives this notification can quickly identify the location of the abnormality.

The switching circuit 70 switches the load state between the transmitting circuit 30 and the receiving circuit 90 and the antenna 80 under the control of the CPU 20 . The switching circuit 70 is configured by a switch that switches the connection destination of the transmitting circuit 30 and the receiving circuit 90 to the antenna end 81 or a terminating resistor (eg, 50Ω).

During self-diagnostic processing, the CPU 20 switches the connection destination of the switching circuit 70 from the antenna end 81 to the terminating resistor (eg, 50Ω). Then, the CPU 20 compares the test pattern signal transmitted from the transmitting circuit 30 after switching the connection destination by the switching circuit 70 with the test pattern signal received by the receiving circuit 90 .

For example, the CPU 20 causes the reception circuit 90 to process the waveform of the test pattern signal transmitted from the transmission circuit 30 and the waveform of the test pattern signal transmitted (leaked) from the transmission circuit 30, and the waveform of the output test pattern signal.

Specifically, the waveform of the test pattern signal transmitted from the transmission circuit 30 refers to the waveform of the test pattern signal transmitted from the transmission circuit 30 before the waveform shaping process is performed by the transmission circuit 30 (that is, before the waveform is input to the DAC 31). is a waveform of the test pattern signal. Further, the waveform of the test pattern signal transmitted (leaked) from the transmission circuit 30 is transmitted from the transmission circuit 30, input to the reception circuit 90 via the second coupler 50, and is input to the ADC (I- It is a waveform of a test pattern signal output from chADC 97a, Q-chADC 97b).

As a result of the comparison, the CPU 20 determines whether or not the signals are substantially the same. If they are not substantially the same, it is diagnosed that the transmission circuit 30 or the reception circuit 90 is abnormal. As a result, the CPU 20 can diagnose whether there is an abnormality in the RFID tag reader/writer device 10 by excluding the influence of the RFID tag 101 and the surrounding environment including the arrangement of people and objects beyond the antenna 80. .

Then, during normal operation or when the self-diagnostic process ends, the CPU 20 switches the connection destination of the switching circuit 70 from the terminating resistor to the antenna terminal 81 . This enables communication with the RFID tag 101 by connecting the transmitting circuit 30 and the receiving circuit 90 to the antenna 80 via the antenna end 81 .

When the connection destination of the switching circuit 70 is switched to the antenna end 81, the second coupler 50 guides the transmission signal output from the transmission circuit 30 to the antenna 80, and the transmission signal is output via the antenna 80. be. In this way, the RFID tag reader/writer device 10 issues a transmission signal to the RFID tag 101, which is an instruction to issue a read command for reading information.

Further, when the RFID tag reader/writer device 10 receives a reflected wave, which is a response signal from the RFID tag 101, to the antenna 80, the second coupler 50 receives the reflected wave, which is a response signal from the RFID tag 101 input from the antenna 80, as Output to the receiving circuit 90 . The second coupler 50 also outputs the signal leaked from the transmission circuit 30 to the reception circuit 90 .

The receiving circuit 90 includes a fourth coupler 91, a third power detector 92, a distributor 93, a hybrid circuit 94, an I-ch receiving mixer 95a, a Q-ch receiving mixer 95b, an I-ch receiving baseband processing circuit 96a, a Q It has a -ch reception baseband processing circuit 96b, an I-ch ADC 97a and a Q-ch ADC 97b. The receiving circuit 90 may have a circuit configuration not shown in FIG. Hereinafter, the circuit configuration within the receiving circuit 90 may be referred to as a "receiving system".

FIG. 3(4) is a diagram showing an example of the configuration of the fourth coupler 91. As shown in FIG. Since the configuration of the fourth coupler 91 is substantially the same as the configuration of the first coupler 35 in FIG. 3(1), redundant description is omitted by using the same reference numerals.

In the fourth coupler 91, the signal output from the second coupler 50 is input to the first terminal P1. The second terminal P2 outputs the signal input to the first terminal P1 to the distributor 93 . Since the third terminal P3 is not used in the fourth coupler 91, it is connected to a terminating resistor (eg, 50Ω). The fourth terminal P4 is configured as a coupling output terminal, and part of the signal (power) input to the first terminal P1 is transmitted to the third power detector 92. The third power detector 92 detects a voltage converted from the power of the signal transmitted from the fourth coupler 91 as power.

Information indicating the power (dBm) that can be detected by the third power detector 92 in a normal state is stored in the storage unit 21 in advance. Therefore, the CPU 20 determines whether or not the power detected by the third power detector 92 is within the expected range of power (electric power) that can be detected in a normal state. Even if there is no device 61, it is possible to diagnose whether or not the transmission circuit 30 has an abnormality. As the expected range, for example, an error range of power that can be detected by the third power detector 92 in a normal state can be set.

When diagnosing that there is an abnormality in the transmission circuit 30, the CPU 20 notifies a host device such as the PC 300 or a server (not shown) of the abnormality. As the contents of the notification, for example, a message to the effect that there is an abnormality in the transmission circuit 30 can be displayed on the display or notified by a speaker. The administrator of the RFID tag reader/writer device 10 who receives this notification can quickly identify the location of the abnormality.

Also, the third power detector 92 can detect signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 in the second coupler 50 .

Here, a method for adjusting signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 by the matching adjuster 51 will be described. Signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 is a source of noise in the RFID tag reader/writer device 10, and is therefore desirably as small as possible. Therefore, during normal operation or when self-diagnostic processing is terminated, the matching adjuster 51 is adjusted so as to minimize signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 under the control of the CPU 20. . For example, the CPU 20 adjusts the matching adjuster 51 so as to minimize signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 detected by the third power detector 92 .

On the other hand, during self-diagnostic processing, the CPU 20 adjusts the matching adjuster 51 so as to maximize signal leakage from the transmission circuit 30 to the reception circuit 90 . For example, the CPU 20 adjusts the matching adjuster 51 so as to maximize signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 detected by the third power detector 92 . As a result, signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 can be easily detected, and the performance of diagnosing whether there is an abnormality can be improved.

Specifically, the CPU 20 adjusts signal leakage (carrier leak) from the transmission circuit 30 to the reception circuit 90 in the second coupler 50 by changing the directivity of the second coupler 50 . can be done. Directivity is defined in advance as a specification for each frequency band of each coupler. Directivity is calculated from the difference between the amount of leakage from the first terminal P1 to the third terminal P3 and the amount of coupling from the first terminal P1 to the fourth terminal P4.

The coupling amount of the second coupler 50 is defined in advance as a specification for each frequency band of each coupler.

The CPU 20 can reduce the signal (carrier leak) flowing from the transmission circuit 30 to the reception circuit 90 by increasing the amount of isolation (Isolation) from the transmission circuit 30 to the reception circuit 90 . The amount of isolation (Isolation), the directivity (Directivity) and the amount of coupling (Coupling amount) have the relationship of formula (1).
Isolation = Directivity + Coupling (1)

The matching adjuster 51 is configured to be able to adjust the capacitance component (C), the inductance component (L), and the like. Therefore, the CPU 20 can adjust the impedance of the matching adjuster 51 by adjusting the capacitance component (C) and the inductance component (L) of the matching adjuster 51 . Therefore, the CPU 20 can adjust the isolation amount (Isolation) to the third terminal P3 by adjusting the impedance of the matching adjuster 51 . As a result, the CPU 20 can adjust the signal (carrier leak) flowing from the transmission circuit 30 to the reception circuit 90 by adjusting the capacitance component (C) and the inductance component (L) of the matching adjuster 51 .

In this manner, during the self-diagnostic process, the matching adjuster 51 is adjusted so as to maximize signal leakage from the transmission circuit 30 to the reception circuit 90, thereby increasing the sensitivity of receiving the test pattern signal. .

When the switching circuit 70 connects the transmission circuit 30 and the reception circuit 90 to the antenna terminal 81 , the distributor 93 distributes the signal sent from the antenna 80 via the antenna terminal 81 via the second coupler 50 . to receive.

In addition, when the switching circuit 70 switches the transmission circuit 30 and the reception circuit 90 from the antenna end 81 to the terminating resistor, the distributor 93 has the carrier leak amount leaking from the transmission circuit 30 in the second coupler 50. receive a signal. The splitter 93 splits the received signal into two signals and outputs the split signals to the I-ch reception mixer 95a and the Q-ch reception mixer 95b, respectively.

The hybrid circuit 94 outputs the signals received from the local oscillator 40 to the I-ch reception mixer 95a and the Q-ch reception mixer 95b as signals having a 90° phase shift. Each of the I-ch reception mixer 95a and the Q-ch reception mixer 95b multiplies the signal from the distributor 93 inputted thereto by the local oscillator signal outputted from the local oscillator 40. FIG. As a result, the received signal is down-converted to the frequency of the local oscillator signal output from the local oscillator 40 . The local oscillator signal multiplied by the I-ch reception mixer 95 a and the Q-ch reception mixer 95 b has the same frequency band as the local oscillator signal multiplied by the transmission mixer 33 . In this embodiment, the frequency band to be multiplied by the I-ch reception mixer 95a, the Q-ch reception mixer 95b and the transmission mixer 33 is the "920 MHz band", but it is not limited to this. For example, it may be "2.4 GHz band", "13.56 MHz band", or the like.

The I-ch reception baseband processing circuit 96a removes unnecessary frequency components from the signal down-converted by the I-ch reception mixer 95a, demodulates it, and outputs it to the I-ch ADC 97a. The I-ch ADC 97a converts the received analog signal into a digital signal and outputs it to the CPU 20. FIG.

The Q-ch reception baseband processing circuit 96b removes unnecessary frequency components from the signal down-converted by the Q-ch reception mixer 95b, demodulates it, and outputs it to the Q-ch ADC 97b. The Q-ch ADC 97b converts the received analog signal into a digital signal and outputs it to the CPU20.

The I-ch reception mixer 95a, the Q-ch reception mixer 95b, the I-ch reception baseband processing circuit 96a, the Q-ch reception baseband processing circuit 96b, the I-ch ADC 97a and the Q-ch ADC 97b are quadrature demodulation circuits of the reception circuit 90. configure. A method for diagnosing the operation of the receiving circuit 90 composed of the quadrature demodulation circuit will be described below.

The CPU 20 adjusts the phase shifter 36 to the phase that maximizes the received signal amplitude at the I-ch ADC 97a. Then, the CPU 20 determines whether the waveform of the test pattern signal output from the I-ch ADC 97a is a normal waveform. Whether or not the waveform is normal is determined by determining whether or not the waveform of the test pattern signal transmitted from the transmission circuit 30 through the CPU 20 is substantially the same as the waveform of the test pattern signal output from the I-ch ADC 97a to the CPU 20. is determined.

If it is determined that the waveform of the test pattern signal output from the I-ch ADC 97a is abnormal when there is no abnormality in the transmission system, it is diagnosed that there is an abnormality in the I-ch reception system. When diagnosing that there is an abnormality in the I-ch receiving system, the CPU 20 notifies an upper device such as the PC 300 or a server (not shown) of the abnormality. As the content of the notification, for example, a message to the effect that there is an abnormality in the I-ch receiving system can be displayed on the display or notified by a speaker. The administrator of the RFID tag reader/writer device 10 who receives this notification can quickly identify the location of the abnormality.

Further, the CPU 20 adjusts the phase shifter 36 to the phase that maximizes the received signal amplitude at the Q-ch ADC 97b. Then, the CPU 20 determines whether or not the waveform of the test pattern signal output from the Q-ch ADC 97b is normal. Whether or not the waveform is normal is determined by determining whether or not the waveform of the test pattern signal transmitted from the transmission circuit 30 through the CPU 20 is substantially the same as the waveform of the test pattern signal output from the Q-ch ADC 97b to the CPU 20. is determined.

If it is determined that the waveform of the test pattern signal output from the Q-ch ADC 97b is abnormal when there is no abnormality in the transmission system, it is diagnosed that there is an abnormality in the Q-ch reception system. When diagnosing that there is an abnormality in the Q-ch receiving system, the CPU 20 notifies an upper device such as the PC 300 or a server (not shown) of the abnormality. As the content of the notification, for example, a message indicating that there is an abnormality in the Q-ch receiving system can be displayed on the display or notified by a speaker. The administrator of the RFID tag reader/writer device 10 who receives this notification can quickly identify the location of the abnormality.

FIG. 4 is a flowchart showing an example of self-diagnostic processing according to this embodiment. The self-diagnostic process is started with the connection destination of the transmission circuit 30 and the reception circuit 90 being the antenna end 81 . First, when the CPU 20 receives an instruction to start self-diagnostic processing from the PC 300, the CPU 20 starts outputting a transmission signal that is an instruction to issue a read command (step S11).

The CPU 20 determines whether or not the power detected by the first power detector 37 is within the expected range of power that can be detected in normal operation (S12). If the power detected by the first power detector 37 is out of the expected range that can be detected under normal conditions (S12: NO), the CPU 20 detects the range from the DAC 31 of the transmission system to the first transmission amplifier 34. is diagnosed as abnormal (S13). Then, the CPU 20 notifies the host PC 300 and the like that there is an abnormality in the range from the transmission system DAC 31 to the first transmission amplifier 34 (S14). When this process ends, the self-diagnostic process (not shown in FIG. 4) ends.

If the power detected by the first power detector 37 is within the expected range of power that can be detected under normal conditions (S12: YES), the CPU 20 determines that the power detected by the second power detector 61 is It is determined whether or not the power is within the detectable expected range (S15).

If the power detected by the second power detector 61 is out of the expected range that can be detected under normal conditions (S15: NO), the CPU 20 controls the transmission system from the first coupler 35 to the second coupler 50. (S16). Then, the CPU 20 notifies the host PC 300 and the like that there is an abnormality in the range from the first coupler 35 to the second coupler 50 of the transmission system (S17). When this process ends, the self-diagnostic process (not shown in FIG. 4) ends.

If the power detected by the second power detector 61 is within the expected range that can be detected under normal conditions (S15: YES), the CPU 20 selects the connection destination of the transmission circuit 30 and the reception circuit 90 as the antenna terminal. 81 is switched to the terminating resistor (S18).

In the second coupler 50, the CPU 20 adjusts the matching adjuster 51 so that signal leakage (carrier leak) from the transmission system to the reception system is maximized (S19). The CPU 20 starts transmitting test pattern signals (S20).

The CPU 20 adjusts the phase shifter 36 to the phase that maximizes the received signal amplitude at the I-ch ADC 97a (S21). Then, the CPU 20 determines whether or not the waveform of the test pattern signal output from the I-ch ADC 97a is normal (S22). If the waveform of the test pattern signal output from the I-ch ADC 97a is abnormal (S22: NO), the CPU 20 diagnoses that there is an abnormality in the I-ch receiving system (S23). Then, the CPU 20 notifies the host PC 300 and the like that there is an abnormality in the I-ch receiving system (S24). When this process ends, the self-diagnostic process (not shown in FIG. 4) ends.

When the waveform of the test pattern signal output from the I-ch ADC 97a is a normal waveform (S22: YES), the CPU 20 adjusts the phase shifter 36 to the phase at which the received signal amplitude at the Q-ch ADC 97b is maximized. (S25). Then, the CPU 20 determines whether or not the waveform of the test pattern signal output from the Q-ch ADC 97b is normal (S26). If the waveform of the test pattern signal output from the Q-ch ADC 97b is abnormal (S26: NO), the CPU 20 diagnoses that there is an abnormality in the Q-ch receiving system (S27). Then, the CPU 20 notifies the host such as the PC 300 that there is an abnormality in the Q-ch receiving system (S28). When this process ends, the self-diagnostic process (not shown in FIG. 4) ends.

If it is determined that the waveform of the test pattern signal output from the Q-ch ADC 97b is a normal waveform (S29: YES), the CPU 20 performs normal setting (state) recovery processing (S29 to S31). . That is, the CPU 20 adjusts the matching adjuster 51 so as to minimize signal leakage from the transmission system to the reception system (S29). Then, the CPU 20 restores the connection destination of the transmission circuit 30 and the reception circuit 90 from the terminating resistor to the antenna end 81 (S30). Also, the CPU 20 resets the phase of the phase shifter 36 to the specified value (S31). When this process ends, the self-diagnostic process ends.

It should be noted that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the present invention at the implementation stage. Also, various inventions can be formed by appropriate combinations of the plurality of constituent elements disclosed in the above embodiments. For example, all the components shown in the embodiments may be combined as appropriate. Furthermore, components across different embodiments may be combined as appropriate. Various modifications and applications are possible without departing from the gist of the invention.

1 RFID tag reader/writer system 10 RFID tag reader/writer device 20 CPU
21 storage unit 30 transmission circuit 31 DAC
32 transmission baseband processing circuit 33 transmission mixer 34 first transmission amplifier 35 first coupler 36 phase shifter 37 first power detector 40 local oscillator 50 second coupler 51 matching adjuster 60 third coupler 61 second power detector 70 switching circuit 80 antenna 81 antenna terminal 90 receiving circuit 91 fourth coupler 92 third power detector 93 distributor 94 hybrid circuit 95a I-ch receiving mixer 95b Q-ch receiving mixer 96a I-ch receiving baseband processing circuit 96b Q -ch reception baseband processing circuit 97a I-ch ADC
97b Q-ch ADCs
100 article 101 RFID tag 101a antenna 200 belt conveyor 300 PC
P1 First terminal P2 Second terminal P3 Third terminal P4 Fourth terminal

Claims (6)

a transmission circuit for transmitting a test signal to an antenna;
a receiving circuit that receives the test signal transmitted from the transmitting circuit in the same frequency band as the transmitting circuit;
a control unit that performs diagnosis based on the test signal transmitted from the transmission circuit and the test signal received by the reception circuit;
The control unit is a wireless device that diagnoses the presence or absence of an abnormality in the wireless device by determining the test signal that has leaked into the receiving circuit,
The reception circuit includes a distributor, an I-ch reception mixer, and a Q-ch reception mixer, and the distributor divides the received signal into two signals, and divides the divided signals into the I-ch reception mixer. Output to the mixer and the Q-ch receiving mixer,
The transmission circuit further comprises a phase shifter that adjusts the phase of the test signal transmitted from the transmission circuit,
The control unit diagnoses the operation of the receiving circuit composed of a quadrature demodulation circuit by adjusting the phase of the test signal using the phase shifter.
A wireless device characterized by: The wireless device of claim 1, wherein
further comprising a coupler connected between the transmitting circuit and the receiving circuit;
The control unit controls the waveform of the test signal transmitted from the transmission circuit through the control unit and the waveform of the test signal transmitted from the transmission circuit and output from the reception circuit to the control unit via the coupler. and are substantially the same, and if they are not the same, it is diagnosed as abnormal. The radio device according to claim 1 or 2,
The transmission circuit further comprises a power detector that detects the power of the test signal based on the test signal transmitted from the transmission circuit,
The radio apparatus according to claim 1, wherein the control unit determines whether or not there is an abnormality in the transmission circuit based on the power detected by the power detector. The radio device according to any one of claims 1 to 3,
further comprising a switching circuit for switching a load state between the transmitting circuit and the receiving circuit and the antenna;
The radio apparatus, wherein the control section performs diagnosis based on the test signal received by the receiving circuit after switching by the switching circuit. A self-diagnostic method for a wireless device for diagnosing an abnormality in the wireless device,
adjusting the phase of a transmitted test signal to transmit the test signal to an antenna;
receiving in the same frequency band as the test signal transmitted to the antenna;
determining the test signal leaked into the receiving circuit based on the test signal transmitted to the antenna and the received test signal, wherein the adjustment of the phase enables a quadrature demodulation circuit A self-diagnostic method for a wireless device for diagnosing the presence or absence of an abnormality in the wireless device by diagnosing the operation of the receiving circuit comprising :
The receiving circuit includes a distributor, an I-ch receiving mixer, and a Q-ch receiving mixer, and the distributor divides the received signal into two signals, and divides the divided signals into the I-ch receiving mixer. output to a mixer and the Q-ch receive mixer;
A self-diagnostic method characterized by: In the program executed by the computer of the wireless device for diagnosing the abnormality of the wireless device,
adjusting the phase of a transmitted test signal and transmitting the test signal to an antenna;
receiving in the same frequency band as the test signal transmitted to the antenna;
determining the test signal leaked into the receiving circuit based on the test signal transmitted to the antenna and the received test signal , wherein the adjustment of the phase enables a quadrature demodulation circuit A program for diagnosing the presence or absence of an abnormality in the wireless device by diagnosing the operation of the receiving circuit composed of
The receiving circuit includes a distributor, an I-ch receiving mixer, and a Q-ch receiving mixer, and the distributor divides the received signal into two signals, and divides the divided signals into the I-ch receiving mixer. output to a mixer and the Q-ch receive mixer;
A program characterized by

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