JPH0637677A - Antenna circuit foe guiding radio communication - Google Patents

Abstract

(57) [Abstract] [Purpose] When the transmission power of a predetermined station is strong, the input filter of the receiving circuit can be simplified or unnecessary, and the antenna area can be increased or special parts need not be configured for the antenna. (EN) Provided is a guided radio communication system capable of surely receiving a weak signal without fear that the station itself cannot function because the receiving function of the station is masked by this transmission power. A communication transformer 14 is provided between a transmitting antenna circuit and a receiving antenna circuit of the first communication station 1, and the first communication station 1 uses electromagnetic energy formed by a transmitting antenna 12 of the first communication station 1. The receiving antenna 13 was constructed and connected so as to cancel the inductive output of the receiving antenna 13. In this case, the communication transformer 14 has the primary side coil 14a of the transformer connected in parallel to the input side of the transmission antenna 12 of the first communication station 1 so that the transmission transformer 12 has two coils. The secondary coil 14b is connected to the receiving antenna 1 of the first communication station 1.
3 may be connected in series.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way wireless communication system performed between two stations, and in particular, when one station cannot be equipped with a power supply facility, the transmission energy of the other station is used to perform the two-way communication. The present invention relates to an antenna circuit for inductive wireless communication in a bidirectional inductive wireless communication system that enables call communication.

[0002]

2. Description of the Related Art When communication is performed between two stations, an electromagnetic induction communication system is used when the antennas of both stations can be arranged close to each other. For example, as an example of such a communication system, there is an unmanned carrier system, which is often used in factories, warehouses, etc., in which an unmanned carrier is driven according to a control signal from a control device provided on the ground. Further, for measurement of a rotating body in an industrial machine or the like, a means for extracting a measurement signal with a slip ring from a sensor mounted on the rotating body or sending it to a ground station by a wireless device is used. As the communication method between the mobile station and the ground station side as described above, in addition to the above-mentioned means, optical communication by a light emitting device and a light receiving device such as a semiconductor laser is performed, and wireless communication using radio waves is also used. ing. Also,
In order to measure the in-vivo situation, a device for connecting a sensor and a communication function contained in a capsule is swallowed or embedded in a predetermined place in the living body, and when the measurement data is needed, the in-vitro measuring device is used. A command signal is transmitted from the communication device provided in the. The in-vivo communication function has means for transmitting measurement information in response to this transmission signal. Further, magnetic means is used for recording and reading on a card or the like for recording predetermined data formed in a portable manner. In the electromagnetic induction communication system, when it is difficult to install the power supply equipment in one station and the signal processing can be performed with a small amount of power, a method in which the opposite station uses one transmission energy as the power source energy is used. ing. Such means are used as a portable inductive wireless transponder, for example, a station service system that uses an IC card as a commuter pass, and entrance / exit control of a confidential area using a tag. High-speed communication is performed between the master station installed at the entrance and the slave station installed on the IC card or tag. In this way, the IC card does not have an internal power source and uses the energy of the received wave A signal processing circuit and a transmission circuit for a predetermined signal are driven.
Further, as described above, even in the case of a biocapsule or the like, there is a means for utilizing transmission energy from an external communication device without mounting a power source on the capsule.

FIG. 2 shows a wireless communication means, a capsule, or a mobile inductive wireless transponder such as an IC card or a tag, which operates between the ground station and the automatic guided vehicle of the above-mentioned automatic guided system. 1 shows an example of a circuit configuration of a conventional guided wireless communication system that performs simultaneous two-way communication between a possible slave station and a corresponding master station. In FIG. 2, reference numeral 1 denotes a fixed station or a main station of this inductive wireless communication system (hereinafter referred to as a main station), and 10 denotes an electronic circuit device that integrates various signal processing circuits and control circuits of the main station 1. There is.
Reference numeral 2 denotes a mobile station or slave station of this communication system (hereinafter referred to as slave station), and 20 denotes an electronic circuit device that integrates various signal processing circuits and control circuits of the slave station 2. For example, when the master station 1 tries to obtain some information from the slave station 2, a predetermined power is supplied from the command signal output from the electronic circuit device 10 by the transmission circuit 11 having a transmission signal generation function including an oscillation circuit and a modulation circuit. A transmit signal having is created. This transmission signal is supplied to a transmission loop antenna (hereinafter referred to as a transmission antenna) 12. Transmitting antenna 12
The signal current flowing through forms a magnetic field, and the magnetic flux φ ₁₂ interlinking with the receiving loop antenna (hereinafter referred to as the receiving antenna) 23 of the slave station 2 approaching a predetermined position causes an induced current to the receiving antenna 23. The induced current flowing through the reception antenna 23 is detected by the reception circuit 24 as a reception signal, and this reception signal is sent to the electronic circuit device 20. The electronic circuit device 20 detects a predetermined command signal from the received signal. Further, depending on the communication system, the electromagnetic energy contained in the received wave is converted into direct current and used as a power source for each circuit provided in the slave station 2. The electronic circuit device 20 performs a predetermined operation in response to the command signal to create a requested information signal to be transmitted to the main station 1. From the information signal output from the electronic circuit device 20, the transmission circuit 21 having a transmission signal generation function including an oscillation circuit and a modulation circuit generates a transmission signal having a predetermined power. This transmission signal is supplied to a transmission loop antenna (hereinafter referred to as a transmission antenna) 22. A signal current flowing through the transmitting antenna 22 forms a magnetic field, and a magnetic flux φ ₂₁ interlinking with a receiving loop antenna (hereinafter referred to as a receiving antenna) 13 of the main station 1 which is located near a predetermined position is induced in the receiving antenna 13. Apply current. The induced current flowing through the receiving antenna 13 is detected by the receiving circuit 17, converted into a predetermined electronic signal, and sent to the electronic circuit device 10. The electronic circuit device 10 uses the signal for predetermined processing. The magnetic flux φ ₁₁ of the magnetic field formed by the transmitting antenna 12 of the main station 1 that interlinks with the receiving antenna 13 causes an induced current to flow through the receiving antenna 13.

Further, the present invention is a means for supporting an inductive wireless communication system capable of two-way communication between a mobile station such as a portable inductive wireless transponder that is movable and has no power supply and a corresponding master station. Of Japanese Patent Application No. 3-356504 and Japanese Patent Application No. 4-108435 previously filed by the applicant. The invention described in Japanese Patent Application No. 3-356504 has a structure in which the receiving sensitivity of electromagnetic energy formed by the transmitting antenna 12 of the first communication station 1 is substantially minimized as shown in FIG. The receiving antenna 13 formed in the predetermined shape of the first communication station 1 is arranged at a position where it can receive the electromagnetic energy formed by the transmitting antenna 22 of the second communication station 2 which is opposite to the receiving antenna 13. In addition, at least two loop antennas each having the reception antenna 13 of the first communication station 1 formed in a predetermined shape, for example, as shown in FIG.
By combining the loop antennas 13A and 13B, the reception sensitivity of the electromagnetic energy formed by the transmitting antenna 12 of the first communication station 1 is substantially minimized and the electromagnetic energy formed by the transmitting antenna 22 of the second communication station 2 is received. It was arranged at a possible position.

In the invention described in Japanese Patent Application No. 4-108435, as shown in FIG. 6, a sub-coil 12A is wound around a transmission loop antenna 12 of a first communication station 1, and the sub-coil 12A is connected to the first communication station. By connecting to the reception antenna 13 of the first communication station 2, when the second communication station 2 is transmitting, the electromagnetic energy formed by the transmission antenna 12 of the first communication station 1 is transmitted to the reception antenna 13 of the first communication station 1. The reception interference is eliminated. In each of FIGS. 4, 5 and 6 described above, 12a is a transmission signal input line of the first communication station 1, 22a is a transmission signal input line of the second communication station 2, and 13a is a first transmission line. The output line of the reception signal of the communication station 1 is shown.

[0006]

By the way, according to the communication means of the unmanned transport system as described above, in optical communication, there are cases where moisture adheres to the optical system due to humidity or the like, which makes communication difficult. There is a problem that radio waves are limited in terms of used radio waves and radio field strengths by the Radio Law, construction steel frames and the like interfere with communication in a warehouse, and a simple communication system is expensive. The slip ring used for measuring the rotating body may generate noise due to poor contact or the like.
Since the wireless device requires a battery and has a large size, the conditions for attachment are limited and the life of the battery limits the measurement conditions. Magnetic cards can be damaged by strong magnetic fields, making it difficult to install batteries and having battery life issues.

Further, according to the inductive wireless communication system shown in FIG. 2, the transmitting antenna 12 and the receiving antenna 13 of the master station 1 inevitably correspond to the small structural size of the slave station 2 in the configuration shown in FIG. Is located close to. Therefore, the receiving antenna 13 of the master station 1 simultaneously inputs the magnetic flux φ ₁₁ due to the magnetic field formed by the transmitting antenna 12 of the master station 1 and the magnetic flux φ ₂₁ due to the magnetic field formed by the transmitting antenna 22 of the slave station 2. In this case, the signal component input by the receiving antenna 13 of the main station 1 is as shown in FIG. 3 in which the horizontal axis represents the frequency and the vertical axis represents the reception level corresponding to each frequency.
The magnetic flux φ ₁₁ of frequency f ₁ due to the magnetic field formed by the transmitting antenna 12 is much larger than the magnetic flux φ ₂₁ of frequency f ₂ due to the magnetic field formed by the transmitting antenna 22 of the slave station 2. Further, in the receiving circuit 14, its circuit function is masked by an electric signal induced by the magnetic flux φ ₁₁ due to the magnetic field formed by the transmitting antenna 21, and the transmitting antenna 2
In some cases, the necessary communication information cannot be detected from the current induced by the magnetic flux φ ₂₁ due to the magnetic field formed by 2.

In the inductive wireless communication system described with reference to FIG. 2 in the prior art, a large amount of energy is transmitted from the master station without mounting a power supply facility on a mobile body having a slave station,
The means for performing processing and transmission on the electronic circuit on the mobile side using this energy can be used for various other purposes as described above, but as described above, a large amount of energy transmitted from the main station is received by the receiving device of the main station. There is a problem that the necessary transmission signal cannot be received because the transmission signal from the required slave station is masked by inputting by itself.

As a countermeasure against this, there is a means for connecting a filter to the output circuit of the above-mentioned receiving antenna. The filter is a ratio of the transmission energy of the strong first communication station to the transmission energy of the weak second communication station, Due to the frequency difference between the transmission frequency of the first communication station and the transmission frequency of the second communication station, which is determined by the functional configuration of the communication system, and the conditions that are derived from the mutual distance between the antennas, sufficient filter characteristics cannot be obtained.
There is a problem that the interference signal included in the reception signal of the second communication station is attenuated from the required communication signal to the required level difference and cannot be separated. The Japanese Patent Application No. 3 filed by the applicant of the present invention first
The invention described in No. 356504 is excellent in required interference signal removal characteristics, but the area occupied by the transmission / reception coil of the first communication station becomes large, so that IC cards, tags, minute capsules, etc. are targeted for communication. In some cases, it may be difficult to put into practical use. Although the invention of the application of Japanese Patent Application No. 4-108435 is excellent in the rejection characteristic of the interference signal, it may be necessary to enlarge the sub-coil in order to obtain the required separation characteristic, and the volume of the antenna part is large. However, there is a problem that it may be difficult to put into practical use depending on the conditions of the communication system, although the configuration and adjustment are easy.

In order to solve the above problems, the present invention is directed to a bidirectional inductive wireless communication system including a portable inductive wireless transponder which does not have a power source such as an IC card, a capsule, and a tag, when the transmission power of a predetermined station is strong. In addition, it simplifies or does not require a filter of the receiving circuit, and the transmission power masks the receiving function of the station itself without the need to increase the antenna area or configure special parts for the antenna. An object of the present invention is to provide an inductive wireless communication system that can reliably receive weak signals without fear of being unable to do so.
(Issue)

[0011]

In order to solve the above-mentioned problems, an inductive wireless communication antenna circuit of the present invention includes a communication transformer between a transmitting antenna circuit and a receiving antenna circuit of a first communication station. The induction output of the receiving antenna of the first communication station due to the electromagnetic energy formed by the transmitting antenna of the first communication station is canceled. In this case, in the communication transformer, the primary side coil of the communication transformer is connected in parallel to the input side of the transmission antenna of the first communication station with respect to the transmission antenna, while the secondary side of the communication transformer is connected. The coil may be connected in series with the receiving antenna of the first communication station.

[0012]

According to the present invention, as described above, by connecting the communication transformer between the transmitting antenna circuit of the first communication station and the receiving antenna circuit of the first communication station, Receiving interference on the receiving antenna of the first communication station due to electromagnetic energy formed by the transmitting antenna of the first communication station during transmission is removed or attenuated. Therefore, the first
Even if the electromagnetic energy transmitted from the communication station is large, the receiving circuit of the first communication station can reliably receive the signal transmitted from the second communication station without being affected by the large energy. When the communication transformer is connected to the transmitting antenna of the first communication station in parallel with the primary coil of the communication transformer and the secondary coil is connected in series to the receiving antenna of the first communication station. The above operation can be easily realized by a communication transformer having a simple structure. Therefore,
Since the area and volume occupied by each antenna can be minimized, the degree of freedom in designing and manufacturing the arrangement of each antenna is high.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment according to the present invention will be described in detail with reference to FIG. In FIG. 1, the conventional technique shown in FIG.
The same element devices as those of the communication system shown in FIG. In FIG. 1, reference numeral 1 denotes a fixed station or a main station which is a first communication station of this inductive wireless communication system (hereinafter referred to as a main station), and 2 denotes a second station of this communication system.
The communication station is a mobile station mounted on a carrier vehicle or a slave station (hereinafter referred to as slave station) not equipped with a power source incorporated in a capsule or an IC card. 10 in main station 1
Shows an electronic circuit device that integrates various signal processing circuits and control circuits in this communication system. Main station 1
When trying to obtain some information from the slave station 2, a transmission signal having a predetermined power is generated by a transmission circuit 11 having a transmission signal generation function including an oscillation circuit and a modulation circuit from a command signal output from the electronic circuit device 10. To be done. This transmission signal is a loop antenna for transmission (hereinafter referred to as a transmission antenna) 1
2 is supplied. A signal current flowing through the transmitting antenna 12 forms a magnetic field, and a magnetic flux φ ₁₂ interlinking with a receiving loop antenna (hereinafter referred to as a receiving antenna) 23 of the slave station 2 approaching a predetermined position causes an induced current to the receiving antenna 23. Shed. In the slave station 2, reference numeral 20 denotes an electronic circuit device that integrates various signal processing circuits and control circuits received by the slave station 2. The induced current flowing through the reception antenna 23 of the slave station 2 is detected by the reception circuit 24 as a reception signal, and this reception signal is sent to the electronic circuit device 20. The electronic circuit device 20 detects a predetermined command signal from the received signal. The electronic circuit device 20 performs a predetermined operation in response to the command signal to create an information signal to be transmitted to the main station 1. From the information signal output from the electronic circuit device 20, the transmission circuit 21 having a transmission signal generation function including an oscillation circuit and a modulation circuit generates a transmission signal having a predetermined power. This transmission signal is a loop antenna for transmission (hereinafter referred to as a transmission antenna) 2
2 is supplied. A signal current flowing through the transmitting antenna 22 forms a magnetic field, and a magnetic flux φ ₂₁ interlinking with a receiving loop antenna (hereinafter referred to as a receiving antenna) 13 of the main station 1 which is located near a predetermined position is generated in the receiving antenna 13. Apply an induced current. The induced current flowing through the reception antenna 13 of the master station 1 is input to the reception circuit 16 via the filter function circuit 15, and the transmission signal created and transmitted by the slave station 2 is detected and converted into a predetermined electronic signal to be an electronic circuit device. Sent to 10. The electronic circuit device 10 performs the predetermined processing of the signal so that the higher-level function of the communication system (not shown) functions. Further, in the main station 1, the magnetic flux φ _{11 of} the magnetic field formed by the transmitting antenna 12 and interlinking with the receiving antenna 13 causes an induced current to flow through the receiving antenna 13. Further, the primary side coil 14a of the communication transformer 14 is connected in parallel to the circuit coupled from the transmission circuit 11 of the main station 1 to the transmission antenna 12, and the secondary side coil 14b of the communication transformer 14 is connected to the circuit of the main station 1. It is connected in series with a circuit coupled from the receiving antenna 13 to the filter function circuit 15. The communication transformer 14 is configured by winding a primary coil 14a and a secondary coil 14b with a predetermined number of turns on a core 14c having a predetermined magnetic characteristic, as will be described later in detail.

In the above circuit configuration, when a predetermined transmission signal is output from the electronic circuit device 10 of the main station 1, this transmission signal is supplied to the transmission antenna 12 and the transmission antenna 1
The magnetic field formed by the signal current flowing through 2 links the magnetic flux φ ₁₂ to the receiving antenna 23 of the slave station 2 and causes an induced current to flow through the receiving antenna 23. The magnetic field formed by the signal current flowing through the transmitting antenna 12 of the main station 1 also causes a magnetic flux φ ₁₁ to interlink with the receiving antenna 13 of the main station 1 to cause a disturbing induction current that interferes with the magnetic flux φ ₂₁ effective as a received signal. Induces disturbing voltage. Also,
In parallel with the signal current flowing through the transmitting antenna 12 of the main station 1, a current having a same ratio and a predetermined ratio flows through the primary coil 14a of the communication transformer 14. The communication transformer 14 transmits the signal T ₁₁ due to the current flowing through the primary coil 14a to the secondary coil 14b. The signal T ₁₁ transmitted to the secondary coil 14b is linked to the magnetic flux φ ₂₁ and is received by the receiving antenna 1 of the main station 1.
It is added to the disturbance induction current generated in 3. The number of turns of the primary coil 14a of the communication transformer 14 is Nt, the number of turns of the secondary coil 14b is Ni, the applied voltage across the primary coil 14a of the communication transformer 14, that is, the transmission antenna 12 of the main station 1. The voltage applied to both ends is Vt ₁ , and this voltage Vt ₁
And the primary side coils 14a and 2 of this communication transformer 14
When the voltage outputted to the secondary coil 14b of the communication transformer 14 by the turns ratio Ni / Nt of the next coil 14b and Vt _2, the voltage Vt ₂ is represented by the following formula (1). Vt ₂ = − (Ni / Nt) × Vt ... (1) Further, the induced voltage induced in the transmitting antenna 13 of the master station 1 by the magnetic flux φ ₂₁ formed by the transmitting antenna 22 of the slave station 2 is Vi, the secondary side voltage Vt _{2 of the} communication transformer 14
When the input voltage of the filter function circuit 15 to which the output voltage Vi of the receiving antenna 13 of the main station 1 is added is Vo, the voltage Vo is expressed by the following equation (2). Vo = Vt ₂ + Vi (2) The primary side coil 14 a and the secondary side coil 14 b of the communication transformer 14 are set so that Vt ₂ = −Vi in the equation (2).
If the turn ratio Ni / Nt is set to Vo = 0 (3), the main magnetic flux φ ₁₁ formed by the transmitting antenna 12 of the main station 1 causes The interference signal component induced in the receiving antenna 13 of the station 1 is erased. That is, the induction output of the receiving antenna 13 of the first communication station due to the electromagnetic energy formed by the transmitting antenna 12 of the main station 1, that is, the first communication station is canceled by the configuration and connection of the communication transformer 14 described above. Only the signal component induced in the receiving antenna 13 of the master station 1 by the magnetic flux φ ₂₁ formed by the transmitting antenna 22 of the slave station 2 is input to the filter function circuit 15. By the way, depending on the manufacturing conditions of this communication system, the main station 1
Since the coupling coefficient between the transmitting antenna 12 and the receiving antenna 13 cannot be made uniform, the induced voltage Vi induced in the transmitting antenna 13 of the main station 1 described above is not uniform. Therefore, the above-mentioned condition of Vt ₂ = −Vi is not satisfied, and the above equation (3) is not satisfied, and the residual voltage exists. This residual voltage is input to the filter function circuit 15, removed by the filter function circuit 15, and input to the reception circuit 16. Therefore, the above-mentioned residual voltage is applied to the filter function circuit 15
Since only the transmission signal generated and transmitted by the slave station 2 is detected by the receiving circuit 16 and sent to the electronic circuit device 10 by the magnetic flux φ ₁₁ formed by the transmitting antenna 12 of the main station 1, Does not occur. As described above, the main part of the communication interference signal due to the magnetic flux φ ₁₁ formed by the transmitting antenna 12 of the main station 1 is the communication transformer 14
Filter function circuit 15 since it is removed by inserting
It is sufficient to remove only the remaining disturbing signal component, and it is possible to reliably detect only the communication signal without the need for sophisticated filter characteristics.

In the above description, one of the transformers 14 for communication is used.
Winding ratio Ni between the secondary coil 14a and the secondary coil 14b
The case where / Nt is set to a predetermined value has been described. However, if the coupling coefficient between the primary side coil and the secondary side coil is made variable and adjustable, the above-mentioned filter function circuit 15 should be removed. You can also Also, in the above description,
The primary coil 14a of the communication transformer 14 is parallel to the transmitting antenna 12, and the secondary coil 14b is the receiving antenna 1.
Although the case of connecting in series with 3 has been described, depending on the conditions of each antenna and the type of communication transformer, etc.
Other connecting means may be used as long as the expression can be satisfied approximately to the required degree. Communication transformer 1 as described above
Since 4 can be mounted at an appropriate position apart from each antenna circuit, it can be formed in an arbitrary shape and size according to the required performance. In the above description, an example in which the slave station 2 transmits a signal based on the command signal transmitted from the master station 1 has been described, but the master station 1 is always used as an electromagnetic power source for a power supply required by a device equipped with the slave station 2. It can be naturally applied to the case where the slave station 2 transmits energy and transmits a signal under a predetermined condition. In addition, it goes without saying that the antenna circuit for inductive wireless communication according to the present invention can be applied to antenna structures other than those shown in the embodiments and various communication systems.

[0016]

Since the present invention is constructed as described above, the following excellent effects can be obtained. Even if the electromagnetic energy transmitted from the first communication station is large, the receiving circuit of the first communication station is transmitted from the opposite second communication station without being affected by the large energy with the conventional antenna structure. Signal can be reliably received. Even if the electromagnetic energy transmitted from the first communication station is large, the receiving circuit of the first communication station reliably receives the signal transmitted from the opposite second communication station without being affected by the large energy. Therefore, it is possible to effectively form a two-way guided wireless communication system for simultaneous calls. Even if the electromagnetic energy transmitted from the first communication station is large, the receiving circuit of the first communication station reliably receives the signal transmitted from the opposite second communication station without being affected by the large energy. Therefore, the transmission energy of the first communication station can be used for the power supply of the second communication station and the electronic circuit coupled to the second communication station. Even if the electromagnetic energy transmitted from the first communication station is large, the receiving circuit of the first communication station reliably receives the signal transmitted from the opposite second communication station without being affected by the large energy. Therefore, in order to utilize the transmission energy of the first communication station for the power supply of the second communication station and the electronic circuit or the like coupled to the second communication station, a communication system that constantly sends electromagnetic energy from the first communication station Also in
The first communication station can reliably receive the transmission signal from the second communication station. Since it is only necessary to connect a communication transformer to an ordinary inductive radio circuit, the shape and configuration of each antenna can adopt the necessary optimum conditions of this communication system, and the degree of freedom in designing and manufacturing each antenna and its installation state is high. . Since the communication transformer according to the present invention can be arranged at an appropriate position away from each antenna, the degree of freedom in designing and manufacturing the formal shape and arrangement of the communication transformer is high. The filter for removing the transmission frequency of the own station provided in the receiving circuit of the first communication station can be simplified or deleted. According to the present invention, the first power source for the electronic circuit of the second communication station
Since it is possible to use the transmission energy of the communication station and make simultaneous calls, it is possible to measure in a field that was difficult to detect due to the fact that the power supply could not be installed, etc. You can now utilize the communication function.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a configuration of an embodiment for explaining a configuration of an antenna circuit for inductive wireless communication according to the present invention.

FIG. 2 is a schematic block diagram illustrating a configuration of a conventional antenna circuit for inductive wireless communication.

FIG. 3 is a characteristic curve example diagram showing a reception characteristic of a reception antenna for explaining a problem in a conventional guided wireless communication system.

FIG. 4 is a schematic configuration diagram illustrating a configuration example of an inductive wireless communication antenna of the prior application by the applicant.

FIG. 5 is a schematic configuration diagram for explaining a configuration example of an antenna for inductive wireless communication different from that of FIG. 4 of the prior application by the applicant.

FIG. 6 is a schematic configuration diagram illustrating a configuration example of an inductive wireless communication antenna different from those of FIGS. 4 and 5 of the prior application by the applicant.

[Explanation of symbols]

 1: master station (first communication station) 2: slave station (second communication station) 12: transmission antenna of master station (first communication station) 13: reception antenna of master station (first communication station) 14 : Communication transformer 15: Filter function circuit (filter) 22: Transmission antenna of slave station (second communication station) 23: Reception antenna of slave station (second communication station)

Claims (2)

[Claims] 1. In an inductive wireless communication system between two stations, a communication transformer is formed between a transmitting antenna circuit and a receiving antenna circuit of a first communication station by the transmitting antenna of the first communication station. An antenna circuit for inductive wireless communication, which is configured and connected so as to cancel the inductive output of the receiving antenna of the first communication station due to the electromagnetic energy generated. 2. The communication transformer has a primary coil of the communication transformer connected in parallel to the input side of the transmission antenna of the first communication station, while the primary side coil of the communication transformer is connected to the transmission antenna in parallel. The inductive wireless communication antenna circuit according to claim 1, wherein the secondary coil is connected in series to the receiving antenna of the first communication station.