JP2007028111A - Wireless communication system and wireless communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication system and an apparatus enhanced in evanescent communication technology. <P>SOLUTION: The wireless communication apparatus includes: a controller IC; an EEPROM for storing data required for communication such as an identification code; an analog circuit section such as an RF circuit, and an antenna connector. When the apparatus is used at a master apparatus side (base station side), an exciter described later is connected to the antenna connector, and when the apparatus is used at a slave apparatus side (terminal side), a rod antenna is connected to the antenna connector. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication system and a wireless communication apparatus. In particular, the present invention relates to a wireless communication system and a wireless communication apparatus using evanescent communication technology.

  Wireless communication technology is indispensable in the modern society where information networks are highly constructed. Wireless communication includes not only high-power communication such as ship radio and amateur radio, but also relatively power-saving communication such as mobile phone communication, transceiver communication, and wireless LAN communication.

  Among power-saving communications, wireless communication devices that use weak radio waves emit extremely weak radio waves, so (1) anyone, anytime, anywhere, and (2) use wireless communication devices. It is not necessary for a person to take a test and obtain a license qualification (radio operator license). (3) Unlike specific power-saving radio equipment and land mobile stations, the frequency can be freely selected, and there is no interference. (4) It is also possible to install the antenna separately from the radio device main body. Because of these advantages, various types of wireless communication devices such as home-use cordless telephones and transceivers have been put into practical use.

  However, in the conventional wireless communication device, since the radio wave used is extremely weak, the standard of the communication distance is about 30 m with a line of sight, the reaching distance is not sufficient, and it is susceptible to interference interference. was there.

  In addition, in conventional wireless communication devices, even though the radio waves used are extremely weak, radio waves (electromagnetic signals) in the wireless communication space leak outside and can interfere with other wireless communication devices. The range was very limited, its use was limited to circumstances, and the above-mentioned merit could not be utilized to the fullest.

  In general, compared with conventional wired communication, the wireless communication space can be cheaply and easily created, but there are problems such as being interrupted by people and obstacles during communication, and slow communication speed. . In addition, radio waves by wireless communication have a property of going straight, and there is a disadvantage that communication is interrupted when a person or an object blocks between the transmitter and the receiver during communication. Moreover, since the attenuation of radio waves is inversely proportional to the square of the distance, the range in which radio communication can be performed is limited.

Under these circumstances, the present inventors use evanescent waves that can prevent radio waves from leaking from the inside of a structure such as a building to the outside, or can ensure a sufficient communication / communication reachable distance. Inventing so-called evanescent communication technology for performing communication (see Patent Documents 1 to 3), there is still room for improvement (see Patent Documents 1 to 3) for practical use.
WO03103195 WO03009501 WO03009500

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an improved wireless communication system and wireless communication device.

  The present invention includes a base unit of a wireless communication apparatus to which an exciter is connected and a slave unit of the wireless communication apparatus to which a rod-shaped antenna is connected. By injecting a radio signal into a conductor in the structure, a radio communication space by a quasi-static non-propagating electromagnetic field is generated in the structure, and the slave unit of the radio communication device includes the rod antenna. A wireless communication system that receives a wireless signal from a parent device of the wireless communication device via the wireless communication device or transmits a wireless signal to the parent device of the wireless communication device.

  According to the present invention, a wireless communication space (evanescent space) by a quasi-static non-propagating electromagnetic field generated in a structure such as a building or a house by a master unit of a wireless communication device to which an exciter is connected. It can be used to realize a wireless network within the structure. The slave unit of the wireless communication apparatus can communicate with weak radio waves using a simple rod-shaped antenna such as a whip antenna or a rod antenna.

  The wireless communication device includes a modulation / demodulation unit that modulates transmission data with a predetermined modulation method at the time of transmission to generate a baseband signal, and demodulates the baseband signal with a predetermined demodulation method to generate reception data at the time of reception When transmitting, the baseband signal is mixed based on a predetermined local oscillation frequency to generate a radio signal, then the radio signal is amplified to a predetermined level and output, and when received, the received signal is amplified to a predetermined level. After that, it has an analog circuit unit that detects the received signal based on the local oscillation frequency and reproduces a baseband signal, and an antenna connector that connects the exciter or the rod antenna and the analog circuit unit. Is preferred. According to this, the wireless communication device has a common configuration for both the parent device and the child device, and becomes a parent device by connecting an exciter to the antenna connector of the wireless communication device, and becomes a child device by connecting a rod-shaped antenna. Therefore, the versatility and convenience of the wireless communication device can be improved, and the cost for constructing the wireless communication system can be greatly reduced.

  Moreover, it is preferable that the said radio | wireless communication apparatus further has an output adjustment part which optimizes transmission output manually or based on the bit error rate of the said received data. The size of a structure such as a building or a residence is closely related to the wavelength and output level of the radio signal, but according to the present invention, the output level of the radio signal is optimized in accordance with the size of the structure. The wireless signal can be transmitted with an output suitable for the size of the structure forming the wireless communication space.

  Furthermore, it is preferable that the antenna connector of the wireless communication apparatus is configured to be detachable from the exciter or the rod-shaped antenna. According to this, the wireless communication device can be used for both the master unit and the slave unit, and can be changed from the exciter to the rod antenna or from the rod antenna to the exciter at any time. The degree can be further increased.

  Furthermore, the wireless communication device is preferably a card-type wireless communication adapter that can be connected to a computer. According to this, since the wireless communication device is a card-type wireless communication adapter, it can be connected to a card slot of a personal computer and can be used as a small and highly versatile wireless communication device.

  As the frequency of the radio signal, it is preferable to use a lower band of 3-30 MHz short wave band (HF), 30-300 MHz ultra high frequency band (VHF), or 300-3000 MHz ultra-high frequency band (UHF). The wavelength of the short wave (HF) is 100 to 10 m, and the wavelength of the very short wave (VHF) is 10 to 1 m, which is almost the same as the size of a building or a house where an electromagnetic field is generated. It can be used to generate an electromagnetic field inside.

  Furthermore, the structure is a tunnel, a ship, a building, a submarine, an aircraft, a construction site, a factory, or a sports stadium, or a stadium thereof. The conductor in the structure is at least one of a conductor, a pipe, and a structural member. It is.

  The present invention is also a wireless communication device that forms a wireless communication space by a quasi-static non-propagating electromagnetic field in a structure by injecting a wireless signal into a conductor in the structure through an exciter. A controller including a modulation / demodulation unit that modulates transmission data with a predetermined modulation method at the time of transmission to generate a baseband signal, and demodulates the baseband signal with a predetermined demodulation method to generate reception data at the time of transmission; Sometimes a baseband signal is mixed based on a predetermined local oscillation frequency to generate a radio signal, then the radio signal is amplified to a predetermined level and output, and upon reception, the received signal is amplified to a predetermined level, Connecting the analog circuit unit that detects the received signal based on the local oscillation frequency and reproduces the baseband signal, and the exciter or the rod antenna and the analog circuit unit It is also a wireless communication device and a that the antenna connector.

  The wireless communication device is preferably provided with an excitation circuit that is inserted between the analog circuit unit and the antenna connector and includes a series circuit of a resistor and a capacitor. According to this, when connecting the terminal devices provided with the wireless communication device by cable, the entire cable is excited and itself constitutes an evanescent space. Therefore, the distance between the farthest terminal devices can be extended to about 2 km, and relatively long-distance wired communication can be realized with a very simple configuration.

  According to the wireless communication system of the present invention, when transmitting voice, image or other data, the electromagnetic signal is transmitted through the conductor in the structure in the wireless communication space in the structure excited by the exciter, and the receiver Because the signal propagates through the conductor as close as possible, it is possible to communicate even though the transmission power is limited to the range of weak power without legal restrictions. In addition, since the radio wave used for communication in the present invention is a radio wave using a pseudo electrostatic magnetic field, the emission of the weak radio wave can be suppressed, and the weak radio wave does not leak out of the wireless communication space.

  Further, according to the wireless communication system of the present invention, the wireless communication device has a common configuration for both the parent device and the child device, and becomes a parent device by connecting an exciter to the antenna connector of the wireless communication device. Since it becomes a subunit | mobile_unit by connecting simple rod-shaped antennas, such as an antenna, the versatility and the convenience of a radio | wireless communication apparatus can be improved, and the cost at the time of building a radio | wireless communications system can be reduced significantly. . In particular, a slave unit of a wireless communication apparatus can communicate with weak radio waves in a wireless communication space using a rod-shaped antenna.

  Prior to describing the embodiments of the present invention, the principle of the present invention will be briefly described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing a conventional radio broadcasting station RS in a simplified manner. A radio signal including information to be broadcast is sent to a high antenna tower T made of metal via a cable CBL. The tower is made of a conductive metal and generates radio waves W. The radio wave W propagates in the atmosphere far and reaches the radio receiver R inside the house H. The wireless receiver R detects the radio wave W and converts it into voice and music that can be heard by a person, so that the audience can enjoy them.

  The conventional radio wave used in FIG. 1 is called “far-field” because it is sent far away from the antenna tower T and can be received by the radio receiver R far away. Create a world. The moving radio wave W propagates according to the well-known radio wave propagation theory, but it looks like ripples spreading on the surface of a quiet pond that is disturbed by dropping stones. A typical wireless communication device transmits electromagnetic energy to a remote receiver using radio waves that travel farther away.

  FIG. 2 is a schematic diagram showing an electromagnetic field completely different from this. This field is called “quasi-static field” or “evanescent space”. In order to generate such an electromagnetic field, the signal S is generated via a conductor connected to the rectangular metal casing E shown in FIG. 2 or using a device called an exciter (exciter) described later. Supply. When energy is coupled to the cavity in the housing E, an electromagnetic field is generated in the cavity. The cavity can be formed by the surface of a metal body or a grid of conductive wires. Inside the metal housing E, a field completely different from the “far field” shown in FIG. 1 is formed. There are no radio waves that propagate or move inside the metal housing E of FIG. Every point inside the enclosure E is associated with an energy level or voltage level. The voltage level at each point changes based on the frequency of the input signal that gives energy to the housing and the size of the housing. This electromagnetic field is called a “quasi-static” field because it does not produce radio waves that reach distant receivers. The receiver placed inside the housing E shown in FIG. 2 detects the signal S, but differs from a conventional radio in that the receiver is a quasi-static non-propagating wave (this is referred to as an evanescent wave). It may be present “inside”. It should be noted that the general technical term for a conductive housing energized to generate a limited electromagnetic field is “cavity resonator”.

  In the present invention, the electromagnetic field phenomenon as shown in FIG. 2 is used to generate a region or “bubble” in the housing. This electromagnetic field is used to connect many different wireless devices without wiring, and more importantly, it can be used without interference with other existing wireless devices. One of the preferred embodiments of the present invention generates a signal in the ultra high frequency (VHF) band, which is a frequency range of 3 to 30 MHz, and generates a signal in the lower band (up to 400 MHz) of the ultra high frequency (UHF). It can also be generated.

  It is important to select these specific frequency bands because the wavelengths of those frequencies are generally as large as the size of structures (housings) such as buildings and houses that generate electromagnetic fields. is there. This relationship is very important because if the structure is too large, it becomes an antenna that generates a far field, which causes both scattering and multipath.

  In addition, short waves (HF) and very high frequencies (VHF) are generally useful for implementing the present invention because they are generally avoided by users using conventional wireless communication. It is natural that signals propagating in these frequency bands are easily affected by various types of atmospheric noise and human noise.

  Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 3 is a schematic diagram showing a structure used in a wireless communication system according to a preferred embodiment of the present invention.

  In general, a structure or other structure (hereinafter referred to as a structure) 10 such as a building or a house has a wall 12, and a steel frame (conductive frame) or other structural member or an electrical ground shield is provided inside the wall 12. (Shield), wiring, water pipes and other piping, and various other public conductors 14 exist. Any existing conductor 12 in an invisible part of the structure 10 is used as a cavity antenna that generates an electromagnetic field in the interior 20 of the structure 10. The conductors 14 are excited and energized by electromagnetic energy radiated from an exciter (exciter) 16. As a result, various devices such as the receiver 22 can be connected to the LAN without wiring. This LAN can also be connected to public or private telephone lines, satellite receivers, or other interfaces to the outside.

  FIG. 4 is a schematic diagram showing an outline of the radio communication system according to the present embodiment.

  As shown in FIG. 4, this system includes a base unit 402a and a handset 402b of a wireless communication device (hub) in a structure 401 such as a building. The basic configuration of the base unit 402a and the base unit 402b of the wireless communication apparatus is the same. The base unit 402a of the wireless communication apparatus is connected to the exciter 403 by a coaxial cable or other suitable method. These wireless communication devices 402a and 402b are mounted in an independent base station (server) 404 or incorporated in a terminal device 405 such as a personal computer. The base unit 402 a of the wireless communication device is connected to an existing conductor inside the structure 401 via the exciter 403 in order to excite the structure 401. Thus, a signal from the wireless communication device 402a is transmitted to a number of devices in the structure 401 through a conductor, and further connected to another network. In the present embodiment, a router function included in base unit 402a of the wireless communication apparatus may separate signals of various bandwidths or modulation formats and guide them to designated targets. If the device is being monitored or if it is a remotely operated device such as a video receiver that receives data from a VCR or TV, the target can be the processor itself and the target settings can be changed. It may be a remote device. At frequencies below 300 MHz, the transmitter, receiver and all other hardware are operated digitally. In fact, one of the major advantages of this system is that the frequency hardware is much cheaper than that for the band above 2.4 GHz.

  FIG. 5 is a block diagram showing a circuit configuration of the wireless communication apparatus according to the present embodiment.

  As shown in FIG. 5, the wireless communication apparatus 500 includes a controller IC 501, an EEPROM 530 that holds identification codes and other data necessary for communication, an analog circuit unit 540 such as an RF circuit, and a connector 550. . A predetermined voltage (for example, 1.8 V) is supplied from the external power source 560 to the controller IC 501, and a highly accurate reference clock is supplied from the crystal oscillator 570.

  The controller IC 501 includes a CPU 502, a physical control unit 503, a digital modulation unit (MOD) 504, a D / A conversion unit 505, a digital demodulation unit (DEM) 506, an A / D conversion unit 507, and the like. The CPU 502 is connected to a connector of an external device such as a computer via an input / output interface, and performs communication control such as MAC control, transmission time control, and availability determination together with the physical control unit 503. Digital data input via the input / output interface is input to the digital modulation unit 504 via the CPU 502 and the physical control unit 503. The digital modulation unit modulates digital data according to a predetermined modulation method to generate a baseband signal. As a modulation method, it is preferable to use a phase modulation method such as BPSK or QPSK, or an amplitude modulation method such as 16QAM or 64QAM.

  The data modulated in this way is converted into an analog signal by the D / A converter 505 and then input to the mixer (MIX) 510 via the switch (SW) 508 and the low-pass filter (LPF) 509. Here, the switch 508 switches transmission / reception in cooperation with an AGC amplifier described later under an instruction from the physical control unit 503. During transmission, the transmission line is on and the reception line is off. It becomes a state. The low pass filter 509 removes high frequency noise components higher than a predetermined frequency (for example, 33 MHz). The mixer 510 mixes the baseband signal and the carrier signal to generate an RF signal having a predetermined frequency (for example, 35 MHz). A local oscillator (OSC) 511 that generates a predetermined frequency signal (for example, 50 MHz) is used for generation of the carrier signal at this time.

  After the noise component is removed from the RF signal by the band pass filter 512, the RF signal is input to the transmission low noise amplifier 514 via the attenuator 513. The attenuator 513 is used to attenuate the RF signal to a predetermined level so that the waveform is not distorted by subsequent amplification. The RF signal is amplified to a predetermined output level (for example, 2.85V) by the transmission low noise amplifier 514, and then further amplified to a predetermined level (for example, 3.3V) by the transmission power amplifier 515. This RF signal is supplied to an antenna (not shown) connected to an antenna connector 519 via an impedance matching attenuator (ATT) 516, a high frequency switch 517, and a band pass filter 518, and is weak radio waves (transmission frequency 322 MHz or less). , At a point 3 m away from the transmitter, the transmission output is transmitted as a radio wave having a maximum electric field strength of 500 μV / m). Here, when this device is used for the base unit (base station side), an exciter described later is connected to the antenna connector 519 via a coaxial cable, and is used for the handset side (terminal side). Is connected to a rod antenna.

  For data reception, the procedure is almost the reverse of data transmission. That is, an RF signal received by an antenna (not shown) is input to the reception linear amplifier 521 at the preceding stage via the band pass filter 518, the high frequency switch 517, and the impedance matching attenuator 520. The RF signal is amplified to a predetermined level by the reception linear amplifier 521 at the preceding stage, further amplified by the reception linear amplifier 522 at the subsequent stage, and then carrier detected by the mixer 523 to generate a baseband signal. This baseband signal is input to the AGC amplifier 525 via the low-pass filter 524, the gain is adjusted, and then input to the controller IC 501. At the time of transmission, the gain of the AGC amplifier 525 is set to zero, so that the receiving line is turned off. The received signal is first converted into a digital signal by the A / D converter 507 in the controller IC 501 and then input to the digital modulator 506. The digital modulation unit 506 demodulates the digital signal in accordance with a predetermined demodulation method corresponding to the above-described modulation method, and reproduces digital data. The digital data is transferred to an external device such as a computer via the physical control unit 503 and the CPU 502.

  When data is received, the gain of the AGC amplifier 525 is first adjusted. In the gain adjustment, first, the gain of the AGC amplifier 525 is maximized, and the physical control unit 503 receives the power level of the signal obtained in the preamble synchronization stage of the received packet. Based on this signal level, the gain of the AGC amplifier 525 is increased. Converge. The signal at this time is supplied from a line different from the normal reception side line described above. More specifically, the output of the receiving linear amplifier 521 on the normal receiving line is branched, and one of the outputs is sent to the physical control unit 506 via the receiving linear amplifier 526, the band pass filter 527 and the received power detector 528. Supplied. Here, the bandpass filter 527 is used to remove clock noise around 35 MHz emitted from an external device such as a computer, and the reception power detector 528 detects a received signal to generate a carrier signal. Used for. The power level of the carrier signal thus obtained is used as a reference for initial AGC adjustment.

  Next, an exciter connected to the base station side wireless communication device will be described.

  6A and 6B are diagrams showing an example of the configuration of the exciter. FIG. 6A is a side view thereof, FIG. 6B is an enlarged side view thereof, and FIG. 6C is a perspective view thereof. Yes.

  As shown in FIG. 6, the exciter includes a hemispherical exciter body 600 and a physical support 601 that maintains the posture of the exciter body 600. Since the exciter body 600 is hemispherical, this exciter is a “three-dimensional exciter”. In the case of a three-dimensional exciter, the structure is complicated, but the stability of communication is high.

  The power required to communicate is related to the required signal quality, but is proportional to the total area of the structure or campus that forms the wireless communication space. On the other hand, the most important dimension for the generation of weak radio waves is the minimum distance between opposing conductors of a structure or premises. This minimum distance defines the cut-off frequency for the structure and determines whether weak radio waves are generated in the closed space when the exciter function is performed.

  The posture of the exciter body 600 is held by the support body 601. In order to obtain an optimum effect, the hemispherical exciter body 600 is preferably installed inside a space surrounded by a conductor, and is preferably juxtaposed with respect to the wall 620 as shown in FIG. In addition, the exciter body 600 is preferably installed almost in the middle of the floor 621 and the ceiling 622, and is preferably installed directly facing the conductor (conductive element).

  In this embodiment mode, the support body 601 includes a support column 602 and a spacer 603. Both the support 602 and the spacer 603 are made of a conductive material. The support column 602 is a part of the support body 601. In order to avoid a conductive path between the exciter body 600 and the electrical ground of the structure, the support column 602 and the spacer 603 are disposed at a specific location (in this embodiment, the support column 602 is adjacent to the floor 621, The spacer 603 is provided with a dielectric insulator (not shown) at a place where it is connected to the exciter body 610. Preferably, the support column 602 is made of a hollow and conductive material, and the spacer 603 is made of a known bracket to increase the strength.

  The spatial dimensions regarding the location and size of the exciter body 600 are very important. In order to use the exciter efficiently, the exciter body 600 must be installed closer to λ / 8 from the conductive element on the wall, where λ is the highest operating frequency.

  The exciter body 600 is controlled by the above-described wireless communication device and is supplied with power. In the transmission mode, the exciter body 600 gives energy to the conductor (conductive element) 623.

  Electromagnetic energy from the wireless communication device is injected into the coaxial cable 604 to “excite” the conductor 623. The central conductor 605 of the coaxial cable 604 is attached to the hemispherical exciter body 600, and the shield 606 of the coaxial cable 604 is electrically connected to the spacer 603, the conductor 623, and the wall 620. As shown in FIGS. 6B and 6C, the shield 606 is electrically connected to the conductor 623 in the wall 620.

  Assuming that the highest frequency used is λ, the effective diameter of the hemispherical exciter body 600 is less than λ / 8, which is large enough to form a measurable fractional reactance for the input transmission line. If so, the structure is not required to be so strict.

  The hemispherical exciter body 600 has a hollow hemispherical member 607. The hollow hemispherical member 607 is formed of a conductor and has a rim portion 608 at an end thereof. The support column 602 is directly connected to the hollow hemispherical member 607. A set of fan-shaped members 609 having a predetermined angle extends outward and forward from the hollow hemispherical member 607, joins at the tip thereof, and is connected to the rim portion 608 along the end portion. The non-conductive partition wall 610 is made of, for example, acrylic resin, and extends in the lateral direction inside the hollow hemispherical member 607, contacts the inner surface of the fan-shaped member 609, supports the structure, and is formed with the hollow hemispherical member 607. Is divided into an upper half and a lower half.

  A matching circuit block 612 is attached to the surface of the non-conductive partition wall 610. The matching circuit block 612 is connected to a coaxial cable 604 extending along the spacer 603. The other end of the coaxial cable 604 is connected to the antenna connector of the wireless communication device described above, and the output from the wireless communication device is directly supplied to the exciter 600 and the matching circuit block 612.

  The central conductor 605 or its extension is stretched from the wireless communication device to the exciter body 600 to a supply point located at the tip of the sector 609 for conducting electrical signals using the conductor. The energy transferred to the delivery point is a method of exciting the conductor to “go” to radiate across the effective band of the transmitted signal, with the conductive portion of the exciter body, the sector 609 and the hollow The hemispherical member 607 is excited. In light of the ground of the shield 606 of the coaxial cable 604 and the connection to the conductor 623 in the wall 620, the nature of the exciter at the selected frequency is not only normal propagating radiation, but also a bubble ("Faraday trap" The net effect is the generation of an electromagnetic virtual space similar to), or the generation of weak and near-weak waves in a conductor.

  According to the wireless communication apparatus to which the exciter configured as described above is connected, even if the transmission output is suppressed to a weak power range, the electromagnetic signal is generated in the wireless communication space in the structure excited by the exciter. Since it propagates through the conductor and propagates through the conductor to the immediate vicinity of the receiver, a very long communication distance of several kilometers can be realized despite the use of weak radio waves.

  Moreover, since the radio wave used for communication is a radio wave using a pseudo electrostatic field, it is possible to suppress the emission of the weak radio wave, and there is an effect that the weak radio wave does not leak out of the wireless communication space.

  The above-described wireless communication device is provided as a wireless communication card for, for example, a CardBus slot because the hardware for frequency is considerably cheaper than that for a band exceeding 2.4 GHz, and further, the size can be easily reduced. be able to. Alternatively, it can be provided as a stick-like device equipped with a USB interface.

  Next, another example of the exciter will be described.

  7A and 7B are diagrams showing an example of the configuration of the exciter. FIG. 3A is a top view and FIG. 3B is a side view. In addition, since the same code | symbol is attached | subjected about the same component as the exciter of FIG. 2, it does not explain anew here.

  As shown in FIG. 7, the exciter includes a planar fan-shaped exciter body 650 and a physical support 601 that maintains the posture of the exciter body. Since the exciter body 650 has a flat fan shape, the exciter is a “two-dimensional exciter”. In the case of a two-dimensional exciter, the structure is simple, but the stability of communication is high.

  The flat fan-shaped exciter main body 650 has conductive traces 651 that substantially coincide with a cross-section along the plane of the partition wall 610 of the hollow hemispherical member 607 and the fan-shaped member 609 in the hemispherical exciter. The conductive trace 651 is disposed and supported on a planar structural plate 652 formed of a nonconductive material. The central zone 653 inside the conductive trace 652 is a hollow or extension of the structural plate 652. The structural plate 652 is supported by the spacer 603 in the same manner as the method of supporting the structural plate 652 to the hemispherical exciter 600 shown in FIG. 6, and keeps a predetermined distance from the wall 620.

  The exciter body 650 in this embodiment includes a matching circuit block 612 mounted on the structural plate 652, and transmits energy from the central conductor 605 of the coaxial cable 604 to the supply point 613, while the shield 606 is the spacer 603. Is similar to a hemispherical exciter in that it is electrically connected to a conductor 654 present in the wall 620 along the line.

  FIG. 8 is a schematic diagram showing another embodiment of the wireless communication system according to the present invention.

  As shown in FIG. 8, the feature of this embodiment is that a single base station (server) 404 realizes generation of an evanescent space in a plurality of structures. Base unit 402a of the wireless communication device built in base station 404 is connected to exciters 403P and 403Q via coaxial cable 410 in order to excite both structures 401P and 401Q. The coaxial cable 410 is bifurcated by a distributor 411, one is wired in the structure 401P, and the other is wired in the structure 401Q. And it is connected to the existing conductor in the structure 401P through the exciter 403P, and is connected to the existing conductor in the structure 401Q through the exciter 403Q. In this way, a signal from the wireless communication device 402a is transmitted to a number of devices (not shown) in the structure 401P through the conductor, and further to a device in the structure 401Q, for example, the terminal device 405Q illustrated.

  Further, in the present embodiment, copper wire loops 406P and 406Q stretched around the exciters 403P and 403Q are respectively wired around the ceilings of the structures 401P and 401Q. This also forms an evanescent space, so that evanescent communication can be reliably performed even when the conductors in the structures 401P and 401Q are not sufficient.

  In the embodiment shown in FIG. 8, the case where the coaxial cable 410 is bifurcated corresponding to the two structures 401P and 401Q has been described. However, the coaxial cable is more branched and the coaxial cable is connected between the terminal devices. A form of connection is also conceivable.

  FIG. 9 is a schematic diagram showing still another embodiment of the wireless communication system according to the present invention.

  As shown in FIG. 9, this system is a system in which a terminal device 405 including a wireless communication device 402 is connected by a cable. At that time, an excitation circuit 420 called a “mini exciter” is inserted into a connection portion between the output end of the wireless communication device 402 and the coaxial cable 410. The excitation circuit 420 includes a series circuit of resistors and capacitors (RC series circuit). In this embodiment, R = 51Ω and C = 0.1 μF are set. When the terminal devices to which the excitation circuit 420 is connected in this way are connected by the coaxial cable 410 as shown in the drawing, the entire coaxial cable 410 is excited and itself constitutes an evanescent space. Therefore, the distance between the farthest terminal devices can be extended to about 2 km, and relatively long-distance wired communication can be realized with a very simple configuration.

  FIG. 10 is a circuit diagram showing another example of the configuration of the exciter (mini exciter).

  As shown in FIG. 10, the exciter has five capacitors C1 to C5 and two inductors L2 and L4. The exciter shown in FIG. 10 is a kind of low-pass filter. As shown in FIG. 10, in this exciter, a circuit A in which an inductor L2 and a capacitor C2 are connected in parallel and a circuit B in which an inductor L4 and a capacitor C4 are connected in parallel are connected in series. One end of the capacitors C1, C3, C5 is connected to the end of the capacitor, and the other ends of the capacitors C1, C3, C5 are connected to have a common potential. As shown in FIG. 10, in this exciter, the end of the capacitor C1 is “port 1”, the end of the capacitor C5 is port 2, the characteristic impedance of port 1 is Zin (input impedance), and the characteristic of port 2 The impedance is Zout (output impedance).

In the present embodiment, the cutoff frequency is set to fc, Zin = Zout, and the design values of the capacitors C1 to C5 and the inductors L2 and L4 are obtained using the following mathematical formulas (1) to (3). Note that FSF is a frequency scaling coefficient.
FSF = 2π · fc (1)
C = Cn / (FSF · Zin) (2)
L = (Ln · Zin) / FSF (3)

It has been found that the exciter shown in FIG. 10 has the frequency characteristics shown in FIG. Here, the following equations (4) and (5) are established for the frequencies Ω2 and Ω4. Amin is the maximum attenuation.
Ω2 = 3fc · L2 / C2 (4)
Ω4 = 2fc · L4 / C4 (5)

  In this embodiment, the input / output impedance is set to Zin = Zout = 50Ω, the cut-off frequency fc is changed from 3.5 to 100 MHz so as to be a valley of attenuation at the frequency of Ω2 and the frequency of Ω4, and the capacitor C1. The design values of .about.C5 and inductors L2 and L4 were obtained, and the results shown in Table 1 and Table 2 below were obtained.

  As shown in Tables 1 and 2, even when the cut-off frequency fc is changed as appropriate, by selecting the values of the capacitors C1 to C5 and the inductors L2 and L4 appropriately, the connection destination of the exciter (transmission / reception) It can be seen that matching with the machine and the axle of the body can be performed (input / output impedances Zin and Zout are made the same as the impedance of the connection destination).

  Next, refer to Table 3. Table 3 shows the frequency-dependent characteristics of the scattering parameter (Scattering Parameter, S parameter) of the exciter shown in FIG. This frequency dependence characteristic is the element constant of fc = 45 MHz in Table 2 (C1 = 75PF, C2 = 5.5PF, C3 = 110PF, C4 = 15PF, C5 = 70PF, L2 = 0.26 μH, L4 = 0.21 μH). Is used.

  FIG. 12 is a graph showing the frequency dependence of the S parameter shown in Table 3. In FIG. 12, “♦” indicates the S parameter S21 (forward impedance characteristic), “■” indicates the S parameter S11 (input side impedance characteristic), and “Δ” indicates the S parameter S22 (output side impedance characteristic).

  The preferred embodiments of the present invention have been described above in detail. However, those skilled in the art having general techniques related to the present invention will be able to make various improvements and improvements in accordance with the spirit of the invention described in the claims. Would be possible. In other words, the above-described system and apparatus show preferred embodiments, and are not intended to impose a limitation on the present invention or the claims.

  The present invention uses the lower band of short wave (HF), ultra high frequency (VHF), or ultra high frequency (UHF) to generate an electromagnetic field in a structure such as a building or a house, thereby By using the electromagnetic field for communication as a resonator that generates a local quasi-static electromagnetic field, the OA of a computer, a printer, or the like can be used without communication and without being troubled by undue interference of external noise. Various electronic devices such as appliances, televisions, washing machines, refrigerators and other home appliances, lighting devices, air conditioning systems, alarm devices, and the like can be connected. The present invention is applicable to a wide range of applications, including the construction of regional commercial and residential wireless networks.

FIG. 1 is a schematic diagram showing a conventional radio broadcasting station RS in a simplified manner. FIG. 2 is a schematic diagram showing an electromagnetic field completely different from this. FIG. 3 is a schematic diagram showing a structure used in a wireless communication system according to a preferred embodiment of the present invention. FIG. 4 is a schematic diagram showing an outline of the radio communication system according to the present embodiment. FIG. 5 is a block diagram showing a circuit configuration of the wireless communication apparatus according to the present embodiment. 6A and 6B are diagrams showing an example of the configuration of the exciter. FIG. 6A is a side view thereof, FIG. 6B is an enlarged side view thereof, and FIG. 6C is a perspective view thereof. Yes. 7A and 7B are diagrams showing an example of the configuration of the exciter. FIG. 3A is a top view and FIG. 3B is a side view. FIG. 8 is a schematic diagram showing another embodiment of the wireless communication system according to the present invention. FIG. 9 is a schematic diagram showing still another embodiment of the wireless communication system according to the present invention. FIG. 10 is a circuit diagram showing another example of the configuration of the exciter. FIG. 11 is a graph showing frequency characteristics of the exciter shown in FIG. FIG. 12 is a graph showing the frequency dependence of the S parameter shown in Table 3.

Explanation of symbols

CBL cable H Residential R Radio receiver RS Radio broadcasting station S Signal T Antenna tower W Radio wave 10 Structure 12 Wall 14 Conductor 16 Exciter
18 Light 20 Inside of structure 22 Receiver 401 Structure 401P, 401Q Structure 402 (402a, 402b) Wireless communication device 402a Base unit of wireless communication device 402a Slave unit of wireless communication device 403 Exciter
403P, 403Q Exciter (Exciter)
404 Base station (server)
405 Terminal equipment 405Q Terminal equipment 406P, 406Q Copper wire loop 410 Coaxial cable 411 Distributor 420 Excitation circuit 500 Wireless communication device 501 Controller IC
502 CPU
503 Physical control unit 504 Digital modulation unit 505 D / A conversion unit 506 Digital modulation unit 507 A / D conversion unit 508 Switch 509 Low pass filter 510 Mixer 512 Band pass filter 513 Attenuator 514 Transmission low noise amplifier 515 Transmission power amplifier 517 High frequency switch 518 Bandpass filter 519 Antenna connector 520 Impedance matching attenuator 521 Reception linear amplifier 522 Reception linear amplifier 523 Mixer 524 Low pass filter 525 Amplifier 526 Reception linear amplifier 527 Band pass filter 528 Reception power detector 530 EEPROM
540 Analog circuit portion 550 Connector 560 External power source 570 Crystal oscillator 600 Exciter 601 Support body 602 Support column 603 Spacer 604 Coaxial cable 605 Center conductor 606 Shield Hollow 607 Member 608 Rim 609 Fan member 610 Non-conductive partition 611 Inside 620 Wall 622 Ceiling 623 Conductor 650 Planar fan-shaped exciter body 651 Conductive trace 652 Planar structure plate 653 Central zone 654 Conductor

Claims (12)

A base unit of a wireless communication device to which an exciter is connected, and a slave unit of the wireless communication device to which a rod-shaped antenna is connected;
The base unit of the wireless communication device injects a wireless signal into a conductor in the structure via the exciter, thereby creating a wireless communication space by a quasi-static non-propagating electromagnetic field in the structure. Generate
A wireless communication system, wherein a slave unit of the wireless communication device communicates with a master unit of the wireless communication device via the rod antenna. The wireless communication device
A controller including a modulation / demodulation unit that modulates transmission data with a predetermined modulation method at the time of transmission to generate a baseband signal, and demodulates the baseband signal with a predetermined demodulation method at the time of reception; and
After transmission, the baseband signal is mixed based on a predetermined local oscillation frequency to generate a radio signal, and then the radio signal is amplified to a predetermined level and output. At the time of reception, the received signal is amplified to a predetermined level. An analog circuit unit that detects the received signal based on the local oscillation frequency and reproduces a baseband signal;
The wireless communication system according to claim 1, further comprising: a cable for connecting to the exciter or an antenna connector for connecting the rod-shaped antenna and the analog circuit unit.   The wireless communication system according to claim 2, wherein the wireless communication device further includes an output adjustment unit that optimizes a transmission output manually or based on a bit error rate of the received data.   The wireless communication system according to any one of claims 1 to 3, wherein the antenna connector of the wireless communication device is configured to be detachable from the cable or the rod-shaped antenna.   The wireless communication system according to any one of claims 1 to 4, wherein the wireless communication device is a card-type wireless communication adapter connectable to a computer.   The wireless communication system according to any one of claims 1 to 5, wherein the wireless signal has a short wave band.   The wireless communication system according to any one of claims 1 to 5, wherein the wireless signal has an ultra high frequency band.   The radio communication system according to claim 1, wherein the radio signal is a lower band of a very high frequency band.   The wireless communication system according to any one of claims 1 to 8, wherein the conductor is at least one of a conductive wire, a pipe, and a structural member.   The wireless communication system according to any one of claims 1 to 9, wherein the structure is a tunnel, a ship, a building, a submarine, an aircraft, a construction site, a factory, a sports stadium, or a premises thereof. A wireless communication device that forms a wireless communication space by a quasi-static non-propagating electromagnetic field in a structure by injecting a wireless signal into a conductor in the structure through an exciter,
A controller including a modulation / demodulation unit that modulates transmission data with a predetermined modulation method at the time of transmission to generate a baseband signal, and demodulates the baseband signal with a predetermined demodulation method at the time of reception; and
After transmission, the baseband signal is mixed based on a predetermined local oscillation frequency to generate a radio signal, and then the radio signal is amplified to a predetermined level and output. At the time of reception, the received signal is amplified to a predetermined level. An analog circuit unit that detects the received signal based on the local oscillation frequency and reproduces a baseband signal;
A wireless communication apparatus comprising: a cable for connecting to the exciter or an antenna connector for connecting the rod-shaped antenna and the analog circuit unit. A wireless communication apparatus, characterized in that an excitation circuit is provided which is inserted between the analog circuit portion and the antenna connector and is composed of a series circuit of a resistor and a capacitor.

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