JP4247673B2 - Transmission / reception device, transmission device, and reception device - Google Patents

Description

  The present invention relates to a transmission / reception device, a transmission device, and a reception device, and more particularly to a transmission / reception device, a transmission device, and a reception device that are suitable for use when transmitting / receiving signals in a plurality of frequency bands.

  In recent years, with the improvement of information communication technology, wired or wireless networks have progressed, and WAN (Wide Area Network) and LAN (Local Area Network) have become widespread. Standards for wired LAN include IEEE (Institute of Electrical and Electronic Engineers) 802.3x using Ethernet (registered trademark). On the other hand, there is IEEE802.11x as a wireless LAN standard for constructing a network using wireless communication.

  In IEEE802.11x, for example, IEEE802.11a, which is a standard capable of communication at a maximum transmission rate of 54 Mbps (Mega Bits Per Second) using 5 GHz band and adopting OFDM (Orthogonal Frequency Division Multiplexing) as a modulation method, IEEE802.11b that uses DS-SS (Direct Sequence Spectrum Spread) as a modulation method and uses 2.4GHz band, can communicate at maximum of 11Mbps, and uses 2.4GHz band and adopts OFDM as modulation method, up to 54Mbps IEEE802.11g etc. that can be communicated with.

  Each of these wireless LAN communication standards is characterized by the maximum communication speed, the communicable range, and the like. Currently, there are wireless LANs based on any of these standards, and are selected according to the use. That is, for example, both a wireless LAN based on IEEE802.11a using a 5 GHz band and a wireless LAN based on IEEE802.11b using a 2.4 GHz band are constructed in a network in a general home (home network). In some cases, a plurality of wireless LANs having different standards are provided in the same area, and the user accesses the plurality of wireless LANs using a single information processing apparatus (for example, a personal computer). Sometimes.

  Further, even if a plurality of wireless LANs having different standards described above are constructed in different locations, for example, a user using a portable notebook personal computer, PDA (Personal Digital Assistants), or the like moves the location. In some cases, each wireless LAN is connected. For example, at home, a user who has connected a laptop personal computer to a wireless LAN based on IEEE802.11a takes the laptop personal computer and moves to a coffee shop where a wireless LAN based on IEEE802.11b is built. Then, it is conceivable to connect a notebook personal computer to the wireless LAN based on IEEE802.11b.

  In such a wireless LAN, for example, when a network is constructed using a router (in the case of infrastructure), the network side (router side) has an access having a wireless communication function conforming to the above-described wireless LAN communication standard. A personal computer in which a point is installed and a LAN card having a wireless communication function for a terminal having a specification conforming to the above-mentioned wireless LAN communication standard is installed, or a personal computer having a function equivalent to this LAN card Etc. establish a network by performing wireless communication with this access point. That is, in this case, each terminal device is connected to a wired network or connected to another terminal device via an access point. However, for example, IEEE802.11a uses the 5 GHz band, IEEE802.11b and IEEE802.11g use the 2.4 GHz band, and the communication processing may not be compatible between the standards. The standard of the card (wireless communication function of the terminal device) needs to match.

  As described above, there are cases where a plurality of networks are constructed using a plurality of wireless LAN communication standards, and a case where one terminal device is connected to a plurality of networks based on different wireless LAN communication standards. Is also possible. In such a case, for example, a plurality of access points having specifications conforming to different wireless LAN communication standards are provided, or a plurality of wireless communication functions having specifications conforming to different wireless LAN communication standards are provided in one terminal device. (LAN card etc.) can be provided, but doing so increases the manufacturing cost and installation location by the number of standards.

  On the other hand, there are an access point, a LAN card, etc. corresponding to a plurality of wireless communications using different frequency bands. For example, there are access points and wireless LAN cards that have a wireless communication function that uses the 5 GHz band and a wireless communication function that uses the 2.4 GHz band, and that support both IEEE 802.11a and IEEE 802.11b standards. .

  In such a communication apparatus, in order to reduce manufacturing cost and circuit scale, there is a method of sharing an amplifier and an antenna used for signal transmission / reception in which the same processing is performed regardless of the frequency band (for example, Patent Documents). 1). A communication circuit of such a wireless communication apparatus is shown as shown in FIG. 1, for example.

  In FIG. 1, a wireless communication device 1 is a decoding wireless device that supports two wireless communication standards, wireless LAN (for example, IEEE802.11b) and Bluetooth (registered trademark). Both wireless LAN and Bluetooth use 2.4 GHz radio waves.

  When the wireless communication device 1 outputs a wireless LAN transmission signal, the chip set 11 that controls the communication processing outputs the wireless LAN transmission signal from the arrow 11 </ b> A and supplies the wireless LAN transmission signal to the power amplifier 13 via the diplexer 12. . The power amplifier 13 amplifies the supplied transmission signal and then supplies the amplified transmission signal to the switch circuit 14. The switch circuit 14 connects the power amplifier 13 on the transmission side and the antenna 15, and outputs the supplied transmission signal from the antenna 15.

  When the wireless communication device 1 outputs a Bluetooth transmission signal, the chip set 11 that controls communication processing outputs the Bluetooth transmission signal from the arrow 11 </ b> B and supplies the Bluetooth transmission signal to the power amplifier 13 via the diplexer 12. . The power amplifier 13 amplifies the supplied transmission signal and then supplies the amplified transmission signal to the switch circuit 14. The switch circuit 14 connects the power amplifier 13 on the transmission side and the antenna 15, and outputs the supplied transmission signal from the antenna 15.

  Conversely, when a signal is received by the antenna 15 of the wireless communication device 1, the received signal is supplied to the switch circuit 14. The switch circuit 14 connects the antenna 15 and the low noise amplifier 16 and supplies a received signal to the low noise amplifier 16. The low noise amplifier 16 amplifies the received signal and then supplies it to the diplexer 17. When the received signal is a wireless LAN signal, the diplexer 17 supplies the received signal to the chip set 11 via the arrow 11C, and supplies the received signal to a wireless LAN processing unit (not shown) built in the chip set 11. To do. When the received signal is a Bluetooth signal, the diplexer 17 supplies the received signal to the chipset 11 via the arrow 11D and supplies it to a Bluetooth processing unit (not shown) built in the chipset 11. To do.

  By using the diplexer 12 and the diplexer 17 in this way, the power amplifier 13, the switch circuit 14, the antenna 15, and the low noise amplifier 16 can be used in both cases of wireless LAN and Bluetooth. The manufacturing cost, circuit scale, power consumption, and the like can be reduced.

JP 2002-208874 A

  However, in the method as described above, communication is performed using a plurality of communication methods using different frequency bands, for example, communication using both 2.4 GHz frequency band and 5 GHz frequency band. In the case of a so-called dual-band wireless communication device, when a transmission signal in the 2.4 GHz frequency band is amplified by a power amplifier, a harmonic component twice that of the transmission signal is generated in the 4.8 GHz band. There is a problem that the component is finally output from the antenna and may affect other devices (for example, other wireless devices and medical devices). That is, there is a problem that the spurious signal is too large and the wireless communication device may not meet the specifications of TELEC (Telecom Engineering Center) (the approval of Japan Approvals Institute for Telecommunications Equipment (JATE) may not be obtained).

  On the receiving side, when receiving a signal in the 2.4 GHz band when receiving a 5 GHz band signal, the received signal in the 2.4 GHz band is amplified by a low noise amplifier. . At that time, the harmonic component of the 4.8 GHz band of the reception signal is also amplified and supplied to the chipset 11 as an interference wave of the reception signal of the 5 GHz band, so that there is a problem that the reception sensitivity is reduced. .

  Specifically, the harmonic component of the 2.45 GHz signal is 4.9 GHz. In IEEE802.11a, currently used carrier frequency is generally 5.15 GHz to 5.25 GHz. For example, in a frequency band that can be used indoors and outdoors on the premise that a telecommunications carrier acquires a license. 4.9 GHz to 5 GHz and 5.03 GHz to 5.091 GHz are also included (Note that these frequency bands will be used for hotspot services combined with the 5.2 GHz band in the future. ing). Therefore, there is a case where the harmonic component (4.9 GHz) of IEEE802.11b is included in the frequency band of IEEE802.11a. In such a case, there is a possibility that the above-described interference or disturbance may occur.

  The present invention has been made in view of such a situation, and when performing a plurality of wireless communication using different frequency bands, the plurality of wireless communication while reducing interference with other frequency bands. The transmission circuit and the reception circuit can be shared.

The transmission / reception apparatus according to the present invention processes transmission data and generates a transmission signal in the first frequency band or the second frequency band, and a first amplification means that amplifies the transmission signal generated by the generation means When the transmission signal amplified by the first amplifying means is a signal in the first frequency band, a first filtering process for blocking or reducing a frequency component of a predetermined frequency or higher is performed on the transmission signal. To pass the frequency component of the first frequency band of the transmission signal, block or reduce the frequency component of the second frequency band, and when the transmission signal is a signal of the second frequency band, a first filter means for passing without first filtering, a first filtered by the first filter means is passed without being in being passed or performed performed periphery Transmitting means for transmitting a transmission signal of several components, receiving means for receiving a signal of a first frequency band or a second frequency band, when receiving a signal of a second frequency band, received by the receiving means By performing a second filter process for blocking or reducing a frequency component equal to or lower than a predetermined frequency with respect to the received signal, the frequency component of the second frequency band of the received signal is passed, and the first frequency band When receiving a signal in the first frequency band by blocking or reducing the frequency component, the received signal is passed through the second filter means without passing through the second filter process, and the second filter means second amplifying means, the received signal amplified by the second amplifying means for amplifying the filtering process is passed performed, or the received signal performed frequency components pass without Ri comprises extracting means for extracting the reception data.

When the transmission signal is a signal in the first frequency band, the first filter means is configured to block or reduce a frequency component that becomes an interference wave of the signal in the second frequency band of the transmission signal . It is possible to perform the filtering process.

  The first filter means controls the grounding of the predetermined low-pass filter circuit and the low-pass filter circuit, so that the low-pass filter circuit performs the first filter process or the first filter process. And a control means for controlling to operate as a through circuit that passes without.

  The low-pass filter circuit includes a first inductor, a second inductor, and a first capacitor. One terminal of the first inductor is connected to the first amplifying means, and the other terminal is the second inductor. And the other terminal of the second inductor is connected to the transmitting means, and the control means can control the grounding of the other terminal of the first capacitor.

  When the transmission signal is a signal in the first frequency band, the control means grounds the other terminal of the first capacitor, operates the low-pass filter circuit as a low-pass filter, and transmits the transmission signal in the second frequency band. The other terminal of the first capacitor can be opened, and the low-pass filter circuit can be operated as a through circuit.

  The control means grounds the other terminal of the first capacitor via a diode, and when the transmission signal is a signal in the first frequency band, by passing a current through the diode, the other terminal of the first capacitor When the transmission signal is a signal in the second frequency band, the other terminal of the first capacitor can be opened by not passing a current through the diode.

  The control means includes, in addition to the diode, a third inductor, a second capacitor, and a resistor. One terminal of the resistor is connected to an input terminal to which a control signal is input, and the other terminal of the resistor is , One terminal of the third inductor, and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is the first capacitor. The other terminal of the first capacitor is connected to the anode of the diode, the cathode of the diode is grounded, and the ground of the other terminal of the first capacitor can be controlled based on the value of the control signal input to the input terminal. .

  The second filter means controls the ground of the predetermined high-pass filter circuit and the high-pass filter circuit, so that the high-pass filter circuit performs a second filter process or a second filter process. And a control means for controlling to operate as a through circuit that passes without.

  The high-pass filter circuit includes a first capacitor, a first inductor, and a second inductor, and one terminal of the first capacitor is connected to the receiving means and one terminal of the first inductor, The other terminal of one capacitor is connected to the second amplifying means and one terminal of the second inductor, and the control means controls the grounding of the other terminal of the first inductor and the second inductor. Can do.

  When receiving the signal of the second frequency band, the control means grounds the other terminal of the first inductor and the second inductor, operates the high-pass filter circuit as a high-pass filter, and operates the first frequency band. When the above signal is received, the other terminals of the first inductor and the second inductor are opened, and the high-pass filter circuit can be operated as a through circuit.

  When the control means grounds the other terminal of the first inductor and the second inductor via a diode and receives a signal in the second frequency band, the control means causes the current to flow through the diode, When the other terminal of the inductor and the second inductor is grounded and a signal in the first frequency band is received, the other terminal of the first inductor and the second inductor is opened by passing no current through the diode. Can be.

  The control means includes, in addition to the diode, a third inductor, a second capacitor, and a resistor. One terminal of the resistor is connected to an input terminal to which a control signal is input, and the other terminal of the resistor is , One terminal of the third inductor, and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is the first inductor. And the other terminal of the second inductor and the anode of the diode, the cathode of the diode is grounded, and based on the value of the control signal input to the input terminal, the first inductor and the second inductor The grounding of the other terminal can be controlled.

The transmission device of the present invention processes transmission data, generates a transmission signal in the first frequency band or the second frequency band, an amplification unit that amplifies the transmission signal generated by the generation unit, and amplification When the transmission signal amplified by the means is a signal in the first frequency band, the transmission signal is subjected to a filtering process for blocking or reducing a frequency component of a predetermined frequency or higher, so that the transmission signal The frequency component of the frequency band is allowed to pass, and the frequency component of the second frequency band is blocked or reduced. When the transmission signal is a signal of the second frequency band, the transmission signal is allowed to pass without being filtered. comprising filter means, and transmission means for transmitting a transmission signal of a frequency component passed through the filter process is passed performed, or performed without the filter means .

When the transmission signal is a signal in the first frequency band , the filter means performs a filtering process so as to block or reduce a frequency component that becomes an interference wave of the signal in the second frequency band of the transmission signal. it can.

  The first filter means operates as a low-pass filter that performs a filtering process or a through circuit that passes the low-pass filter circuit without performing the filtering process by controlling a predetermined low-pass filter circuit and a ground of the low-pass filter circuit. And a control means for controlling so as to be performed.

  The low-pass filter circuit includes a first inductor, a second inductor, and a first capacitor. One terminal of the first inductor is connected to the first amplifying means, and the other terminal is the second inductor. And the other terminal of the second inductor is connected to the transmitting means, and the control means can control the grounding of the other terminal of the first capacitor.

  When the transmission signal is a signal in the first frequency band, the control means grounds the other terminal of the first capacitor, operates the low-pass filter circuit as a low-pass filter, and transmits the transmission signal in the second frequency band. The other terminal of the first capacitor can be opened, and the low-pass filter circuit can be operated as a through circuit.

  The control means grounds the other terminal of the first capacitor via a diode, and when the transmission signal is a signal in the first frequency band, by passing a current through the diode, the other terminal of the first capacitor When the transmission signal is a signal in the second frequency band, the other terminal of the first capacitor can be opened by not passing a current through the diode.

  The control means includes, in addition to the diode, a third inductor, a second capacitor, and a resistor. One terminal of the resistor is connected to an input terminal to which a control signal is input, and the other terminal of the resistor is , One terminal of the third inductor, and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is the first capacitor. The other terminal of the first capacitor is connected to the anode of the diode, the cathode of the diode is grounded, and the ground of the other terminal of the first capacitor can be controlled based on the value of the control signal input to the input terminal. .

The receiving apparatus of the present invention is configured to receive a signal in the first frequency band or the second frequency band and a reception signal received by the receiving means when receiving a signal in the second frequency band. By performing a filtering process for blocking or reducing a frequency component below a predetermined frequency, the frequency component of the second frequency band of the received signal is allowed to pass, and the frequency component of the first frequency band is blocked or reduced, When receiving a signal in the first frequency band, a filter unit that passes the received signal without performing the filtering process, and a frequency component that has been or has been passed through the filtering process by the filtering unit. comprising the amplifying means for amplifying a received signal, and extracting means for extracting the received data from the received signal amplified by the second amplifying means.

  The filter means operates a predetermined high-pass filter circuit and a ground circuit of the high-pass filter circuit so that the high-pass filter circuit operates as a high-pass filter that performs a filtering process or a through circuit that passes without performing the filtering process. And control means for controlling as described above.

  The high-pass filter circuit includes a first capacitor, a first inductor, and a second inductor, and one terminal of the first capacitor is connected to the receiving means and one terminal of the first inductor, The other terminal of one capacitor is connected to the second amplifying means and one terminal of the second inductor, and the control means controls the grounding of the other terminal of the first inductor and the second inductor. Can do.

  When receiving the signal of the second frequency band, the control means grounds the other terminal of the first inductor and the second inductor, operates the high-pass filter circuit as a high-pass filter, and operates the first frequency band. When the above signal is received, the other terminals of the first inductor and the second inductor are opened, and the high-pass filter circuit can be operated as a through circuit.

  The control means includes, in addition to the diode, a third inductor, a second capacitor, and a resistor. One terminal of the resistor is connected to an input terminal to which a control signal is input, and the other terminal of the resistor is , One terminal of the third inductor, and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is the first inductor. And the other terminal of the second inductor and the anode of the diode, the cathode of the diode is grounded, and based on the value of the control signal input to the input terminal, the first inductor and the second inductor The grounding of the other terminal can be controlled.

  When the control means grounds the other terminal of the first inductor and the second inductor via a diode and receives a signal in the second frequency band, the control means causes the current to flow through the diode, When the other terminal of the inductor and the second inductor is grounded and a signal in the first frequency band is received, the other terminal of the first inductor and the second inductor is opened by passing no current through the diode. Can be.

In the transmission / reception apparatus of the present invention, transmission data is processed, a transmission signal of the first frequency band or the second frequency band is generated, the generated transmission signal is amplified, and the amplified transmission signal is the first In the case of a frequency band signal, a first filter process for blocking or reducing a frequency component of a predetermined frequency or higher is performed on the transmission signal, and the frequency component of the transmission signal in the first frequency band is passed. In addition, when the frequency component of the second frequency band is cut off or reduced and the transmission signal is a signal of the second frequency band, the transmission signal is passed without performing the first filtering process, and the first filter A transmission signal having a frequency component that has been passed with or without being processed is transmitted, a signal in the first frequency band or the second frequency band is received, and the second frequency band is received. When the received signal is received, a second filter process for blocking or reducing a frequency component equal to or lower than a predetermined frequency is performed on the received signal, whereby the frequency component of the received signal in the second frequency band is received. And the frequency component of the first frequency band is blocked or reduced, and when the signal of the first frequency band is received, the received signal is passed without performing the second filtering process, The received signal of the frequency component that is passed with or without being filtered is amplified, and received data is extracted from the amplified received signal .

In the transmission apparatus of the present invention, transmission data is processed, a transmission signal of the first frequency band or the second frequency band is generated, the generated transmission signal is amplified, and the amplified transmission signal is the first When the signal is a frequency band signal, the transmission signal is subjected to a filtering process for blocking or reducing a frequency component of a predetermined frequency or higher so that the frequency component of the first frequency band of the transmission signal is passed. When the frequency component of the second frequency band is cut off or reduced and the transmission signal is a signal of the second frequency band, the transmission signal is passed without filtering, and is passed with filtering. Alternatively, a transmission signal having a frequency component passed without being transmitted is transmitted .

In the receiving apparatus of the present invention, when a signal in the first frequency band or the second frequency band is received and a signal in the second frequency band is received, the received signal is equal to or lower than a predetermined frequency with respect to the received signal. By performing filtering processing to cut off or reduce the frequency component, the frequency component of the second frequency band of the received signal is passed, and the frequency component of the first frequency band is cut off or reduced. When receiving a signal in the frequency band, the received signal is passed through without being filtered, and the received signal of the frequency component that is passed through with or without being filtered is amplified and amplified. Received data is extracted from the received signal .

  According to the present invention, a signal can be transmitted, received, or transmitted / received. In particular, when a plurality of radio communications using different frequency bands are performed, the transmission circuit and the reception circuit can be shared in the plurality of radio communications while reducing interference with other frequency bands.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 2 shows a configuration example of a wireless communication unit to which the present invention is applied. In FIG. 2, a wireless communication unit 31 is a dual-band wireless communication unit built in a communication device such as an access point or a LAN card, as will be described later, a transmission unit 32 that performs transmission processing, and reception processing The receiving unit 33 is configured to perform the following.

  The wireless communication unit 31 includes a communication control unit 41 that controls communication processing, and a diplexer circuit that supplies one of two transmission signals of different frequency bands supplied from the communication control unit 41 to the wideband power amplifier 43. 42, a wideband power amplifier 43 that amplifies the transmission signal supplied from the diplexer circuit 42, a filter unit 44 that performs filtering on the output of the wideband power amplifier 43 under the control of the transmission control unit 51 of the communication control unit 41, and an antenna 46 Is a filter that performs filtering on the received signal supplied through the switch circuit 45 under the control of the switch circuit 45 that connects to the circuit on the transmission side or the circuit on the reception side, and the reception control unit 52 of the communication control unit 41 Section 47, broadband low noise amplifier 48 for amplifying the output of filter section 47, and broadband low noise amplifier 48 An output signal, the diplexer circuit 49 is included for supplying the reception control unit of the communication control unit 41 corresponding to the frequency band of the output signal.

  The communication control unit 41 includes a transmission control unit 51 that controls transmission processing and a reception control unit 52 that controls reception processing. The transmission control unit 51 controls a transmission process for 2.4 GHz band communication that controls transmission processing by wireless communication using the 2.4 GHz band, and for a 5 GHz band communication that controls transmission processing by wireless communication using the 5 GHz band. This is a processing unit that incorporates a transmission control unit 62 and controls dual-band transmission processing of the 2.4 GHz band and the 5 GHz band. The reception control unit 52 controls reception processing by 2.4 GHz band communication for controlling communication processing using 2.4 GHz band and 5 GHz band communication for controlling reception processing by wireless communication using 5 GHz band. This is a processing unit that incorporates the reception control unit 64 and controls the reception processing of the 2.4 GHz band and the dual band of 5 GHz band.

  Further, as will be described later, the transmission control unit 51 controls the operation of the filter unit 44 via the control bus 51A, and operates the filter unit 44 as a low-pass filter or as a through circuit. Similarly, the reception control unit 52 controls the operation of the filter unit 47 via the control bus 52A as described later, and operates the filter unit 47 as a high-pass filter or as a through circuit.

  The transmission unit 32 is a processing unit that performs processing related to transmission processing, and includes a transmission control unit 51 of the communication control unit 41, a diplexer circuit 42, a broadband power amplifier 43, a filter unit 44, a switch circuit 45, and an antenna 46. .

  The reception unit 33 is a processing unit that performs processing related to reception processing, and includes an antenna 46, a switch circuit 45, a filter unit 47, a wideband low noise amplifier 48, a diplexer circuit 49, and a reception control unit 52 of the communication control unit 41. The

  Next, the filter unit 44 will be described. FIG. 3 is a diagram illustrating a detailed configuration example of the filter unit 44 in FIG. 2.

  In FIG. 3, the filter unit 44 includes an input terminal 71 to which a transmission signal is input, a filter processing unit 72 that performs low-pass filter processing on the transmission signal input through the input terminal 71 as necessary, and filter processing. An output terminal 73 that outputs the transmission signal supplied from the unit 72 to the outside of the filter unit 44, an input terminal 74 that inputs a control signal supplied from the transmission control unit 51, and a control that is input via the input terminal 74 The control unit 75 is configured to control the operation of the filter processing unit 72 based on the signal.

  The input terminal 71 is connected to the output terminal of the broadband power amplifier 43 of FIG. 2 and supplied with the output of the broadband power amplifier 43. The output of the broadband power amplifier 43 input to the filter unit 44 via the input terminal 71 is supplied to the inductor 81 of the filter processing unit 72.

  The filter processing unit 72 includes an inductor 81, an inductor 82, and a capacitor 83, and operates as a low-pass filter circuit or a through circuit based on the control of the control unit 75. Specifically, one terminal of the inductor 81 is connected to the input terminal 71, and the other terminal is connected to the inductor 82 and the capacitor 83. The other terminal of the inductor 82 is connected to the output terminal 73. The other terminal of capacitor 83 is connected to diode 91 and inductor 93 of control unit 75.

  The output terminal 73 is connected to one terminal of the switch circuit 45 in FIG. 2 (a terminal different from the terminal to which the filter unit 47 is connected on the side to which the filter unit 47 is connected), and the output of the filter processing unit 72. Is supplied to the switch circuit 45.

  The input terminal 74 is connected to the control bus 51 </ b> A of FIG. 2, and a control signal is supplied from the transmission control unit 51. The supplied control signal is supplied to the resistor 92 of the control unit 75 via the input terminal 74.

  The control unit 75 includes a diode 91, a resistor 92, an inductor 93, and a capacitor 94, and controls the operation of the filter processing unit 72 based on a control signal supplied via the input terminal 74. Specifically, the anode of the diode 91 is connected to the capacitor 83 of the filter processing unit 72 and one terminal of the inductor 93, and the cathode is grounded. One terminal of the resistor 92 is connected to the input terminal 74, and the other terminal is the other terminal of the inductor 93 (the terminal opposite to the terminal to which the anode of the diode 91 is connected) and one of the capacitor 94. Connected to the terminal. The other terminal of the capacitor 94 is grounded.

  The control signal controls the current flowing between the anode and cathode of the diode 91 according to the value. That is, when the value of the control signal is “1”, a voltage is applied to the anode of the diode 91 via the resistor 92 and the inductor 93, and a current is generated between the anode and the cathode. Accordingly, one terminal of the capacitor 83 of the filter processing unit 72 (the terminal to which the diode 91 is connected) is grounded, and the filter processing unit 72 transmits the transmission signal (the broadband power amplifier 43) input from the input terminal 71. The output operates as a low-pass filter. FIG. 4 is a graph illustrating an example of input / output characteristics of the filter processing unit 72 (filter unit 44) when the value of the control signal is “1”. As shown in FIG. 4, when the value of the control signal is “1”, the filter processing unit 72 (filter unit 44) passes the frequency band near 2.4 GHz and cuts off the frequency band near 5 GHz ( Or reduce).

  Further, when the value of the control signal is “0”, no voltage is applied to the anode of the diode 91, so that no current is generated between the anode and the cathode. As a result, one terminal of the capacitor 83 of the filter processing unit 72 (the terminal to which the diode 91 is connected) is opened, and the filter unit 72 transmits the transmission signal (the broadband power amplifier 43) input from the input terminal 71. It operates as a through circuit that does not process anything for the output. FIG. 5 is a graph showing an example of input / output characteristics of the filter processing unit 72 (filter unit 44) when the value of the control signal is “0”. As shown in FIG. 5, when the value of the control signal is “0”, the filter processing unit 72 (filter unit 44) passes the frequency band near 2.4 GHz and the frequency band near 5 GHz.

  The resistor 92 of the control unit 75 is for setting the value of the current flowing through the diode 91 when the value of the control signal is “1”, and the inductor 93 is a choke coil. This is for making the impedance high when the input terminal 74 side of the inductor 93 is viewed from the anode side. By this inductor 93, the high frequency component dropped by the low pass filter 72 does not flow to the inductor 93 side, but all flows to the diode 91 side (falls to GND). The capacitor 94 is a bypass capacitor, which not only removes the noise component included in the control signal, but also assumes that the high frequency component from the low pass filter 72 has leaked through the inductor 93. Moreover, the high frequency component can be removed. Therefore, part or all of these elements can be omitted. The order of the positions of the resistor 92 and the capacitor 94 (connection order) may be reversed (that is, the inductor 93 is connected to one terminal of the resistor 92 and the capacitor 94 is connected to the other terminal. May be)

  Of course, the filter processing unit 72 and the control unit 75 described above may be realized by configurations other than those described above. For example, the filter processing unit 72 has been described as being configured by a T-type circuit, but may be configured by an N-stage ladder-type circuit, or may be configured by a saddle-type circuit. Also good. Of course, an active filter using an active element such as an operational amplifier may be used. The control unit 75 may use a switch element such as a transistor.

  Next, the filter unit 47 of FIG. 2 will be described. FIG. 6 is a diagram illustrating a detailed configuration example of the filter unit 47 of FIG.

  In FIG. 6, a filter unit 47 includes an input terminal 101 to which a received signal is input, a filter processing unit 102 that performs a high-pass filter process on the received signal input via the input terminal 101, and a filter process. An output terminal 103 that outputs the reception signal supplied from the unit 102 to the outside of the filter unit 47, an input terminal 104 that inputs a control signal supplied from the reception control unit 52, and a control that is input via the input terminal 104 The control unit 105 is configured to control the operation of the filter processing unit 102 based on the signal.

  The input terminal 101 is connected to one terminal (a terminal different from the terminal to which the filter unit 44 is connected on the side to which the filter unit 44 is connected) of the switch circuit 45 in FIG. A received signal is supplied. A reception signal input to the filter unit 47 via the input terminal 101 is supplied to the capacitor 111 of the filter processing unit 102.

  The filter processing unit 102 includes a capacitor 111, an inductor 112, and an inductor 113, and operates as a high-pass filter circuit or a through circuit based on the control of the control unit 105. Specifically, one terminal of the capacitor 111 is connected to the input terminal 101 and the inductor 112, and the other terminal is connected to the inductor 113 and the output terminal 103. The other terminal of inductor 112 (the terminal to which capacitor 111 is not connected) is connected to the terminal to which capacitor 111 of inductor 113 is not connected, the anode of diode 121 of control unit 105, and inductor 123. . Similarly, the other terminal (the terminal to which the capacitor 111 is not connected) of the inductor 113 is connected to the terminal to which the capacitor 111 of the inductor 112 is not connected, the anode of the diode 121 of the control unit 105, and the inductor 123. Connected.

  The output terminal 103 is connected to the input terminal of the broadband low noise amplifier 48 of FIG. 2 and supplies the output of the filter processing unit 102 to the broadband low noise amplifier 48.

  The input terminal 104 is connected to the control bus 52 </ b> A of FIG. 2, and a control signal is supplied from the reception control unit 52. The supplied control signal is supplied to the resistor 122 of the control unit 105 via the input terminal 104.

  The control unit 105 includes a diode 121, a resistor 122, an inductor 123, and a capacitor 124, and controls the operation of the filter processing unit 102 based on a control signal supplied via the input terminal 104. Specifically, the anode of the diode 121 is connected to one terminal of the inductor 112 and the inductor 113 and the inductor 123 of the filter processing unit 102, and the cathode is grounded. One terminal of the resistor 122 is connected to the input terminal 104, the other terminal is the other terminal of the inductor 123 (a terminal opposite to the terminal to which the anode of the diode 121 is connected), and one of the capacitors 124. Connected to the terminal. The other terminal of the capacitor 124 is grounded.

  The control signal controls the current flowing between the anode and cathode of the diode 121 according to the value. That is, when the value of the control signal is “1”, a voltage is applied to the anode of the diode 121 via the resistor 122 and the inductor 123, and a current is generated between the anode and the cathode. As a result, one terminal of the inductor 112 and the inductor 113 (the terminal to which the diode 121 is connected) of the filter processing unit 102 is grounded, and the received signal (switch) is input from the input terminal 101 to the filter processing unit 102. It operates as a high-pass filter for the output of the circuit 45). FIG. 7 is a graph illustrating an example of input / output characteristics of the filter processing unit 102 (filter unit 47) when the value of the control signal is “1”. As shown in FIG. 7, when the value of the control signal is “1”, the filter processing unit 102 (filter unit 47) cuts off (or reduces) the frequency band near 2.4 GHz, and the frequency in the 5 GHz band. Let the band pass.

  Further, when the value of the control signal is “0”, no voltage is applied to the anode of the diode 121, so that no current is generated between the anode and the cathode. As a result, one terminal of the inductor 112 and the inductor 113 (the terminal to which the diode 121 is connected) of the filter processing unit 102 is opened, and the filter unit 102 receives the received signal (switch) from the input terminal 101. It operates as a through circuit that does not perform any processing on the output of the circuit 45). FIG. 8 is a graph showing an example of input / output characteristics of the filter processing unit 102 (filter unit 47) when the value of the control signal is “0”. As shown in FIG. 8, when the value of the control signal is “0”, the filter processing unit 102 (filter unit 47) passes both the frequency band near 2.4 GHz and the frequency band near 5 GHz.

  The resistor 122 of the control unit 105 is for setting the value of the current flowing through the diode 121 when the value of the control signal is “1”, and the inductor 123 is a choke coil. This is for making the impedance high when the input terminal 104 side of the inductor 123 is viewed from the anode side. By this inductor 123, the high-frequency component that has fallen by the high-pass filter 102 does not flow to the inductor 123 side, but all flows to the diode 121 side (falls to GND). Capacitor 124 is a bypass capacitor, which not only removes noise components included in the control signal, but also assumes that high-frequency components from high-pass filter 102 have leaked through inductor 123. Moreover, the high frequency component can be removed. Therefore, part or all of these elements can be omitted. The order of the positions of the resistor 122 and the capacitor 124 (connection order) may be reversed (that is, the inductor 123 is connected to one terminal of the resistor 122 and the capacitor 124 is connected to the other terminal. May be)

  Of course, the filter processing unit 102 and the control unit 75 described above may be realized by configurations other than those described above. For example, the filter processing unit 102 has been described as being configured by a saddle type circuit, but may be configured by an N-stage ladder type circuit, or may be configured by a T type circuit. Also good. Of course, an active filter using an active element such as an operational amplifier may be used. The control unit 105 may use a switch element such as a transistor.

  The input / output characteristics of the filter circuit 44 or the filter circuit 47 described with reference to FIGS. 4, 5, 7, and 8 are examples, and may be other than those described above. Further, when the filter circuit 44 or the filter circuit 47 is operated as a through circuit, it is desirable that the gain is 0 [dB] in all bands, but in practice, as shown in FIG. 5 and FIG. In some cases, the band is cut off (or reduced). Of course, this may be used positively to delete unnecessary frequency bands.

  Returning to FIG. 2, the operation of the wireless communication device 31 will be described.

  When transmission data is supplied from the outside of the wireless communication unit 31 to the transmission control unit 51 of the communication control unit 41, the transmission control unit 51 acquires the transmission data to be transmitted by wireless communication in a predetermined frequency band. Is supplied to the transmission control unit 61 for 2.4 GHz band communication or the transmission control unit 62 for 5 GHz band communication.

  For example, when communication is performed using a communication method based on the IEEE802.11b standard using the 2.4 GHz band, the transmission control unit 51 supplies the acquired transmission data to the transmission control unit 61 for 2.4 GHz band communication. The 2.4 GHz band communication transmission control unit 61 processes transmission data and generates a transmission signal based on the IEEE802.11b standard, and supplies the transmission signal to the diplexer circuit 42. The diplexer circuit 42 connects the output of the 2.4 GHz band communication transmission control unit 61 to the wideband power amplifier 43 and supplies the output (transmission signal) of the 2.4 GHz band communication transmission control unit 61 to the wideband power amplifier 43. . The broadband power amplifier 43 amplifies the supplied transmission signal and supplies the amplified transmission signal to the filter unit 44.

  In this case, the transmission control unit 51 further supplies a control signal having a value “1” to the filter unit 44 via the control bus 51A. Based on the control signal, the filter unit 44 operates as described above, and performs a low-pass filter process on the transmission signal (amplified transmission signal) supplied from the wideband power amplifier 43. That is, the filter unit 44 blocks (or reduces) unnecessary high-frequency components (for example, a double component of the transmission signal) from the supplied transmission signal so as not to interfere with a signal of 5 GHz band wireless communication. Then, the original 2.4 GHz band signal is extracted and supplied to the switch circuit 45. The switch circuit 45 connects the filter unit 44 to the antenna 46 and outputs the transmission signal supplied from the filter unit 44 to the outside via the antenna 46.

  For example, when communication is performed using a communication method based on the IEEE802.11a standard using the 5 GHz band, the transmission control unit 51 supplies the acquired transmission data to the transmission control unit 62 for 5 GHz band communication. The transmission control unit 62 for 5 GHz band communication processes transmission data and generates a transmission signal based on the IEEE802.11a standard, and supplies the transmission signal to the diplexer circuit 42. The diplexer circuit 42 connects the output of the transmission control unit 62 for 5 GHz band communication to the broadband power amplifier 43, and supplies the output (transmission signal) of the transmission control unit 62 for 5 GHz band communication to the broadband power amplifier 43. The broadband power amplifier 43 amplifies the supplied transmission signal and supplies the amplified transmission signal to the filter unit 44.

  In this case, the transmission control unit 51 further supplies a control signal having a value of “0” to the filter unit 44 via the control bus 51A. Based on this control signal, the filter unit 44 operates as described above, and performs processing as a through circuit on the transmission signal (amplified transmission signal) supplied from the broadband power amplifier 43. That is, the filter unit 44 passes all the frequency bands (frequency bands including at least the 5 GHz band) of the supplied transmission signal, and supplies them to the switch circuit 45 as they are. The switch circuit 45 connects the filter unit 44 to the antenna 46 and outputs the transmission signal supplied from the filter unit 44 to the outside via the antenna 46.

  That is, when performing communication using a communication method based on the IEEE802.11b standard, the filter unit 44 performs a low-pass filter process on the transmission signal to pass a 2.4 GHz band signal used for communication, When communication is performed using a communication method based on the IEEE 802.11a standard by blocking (or reducing) a 5 GHz band signal (harmonic component) that interferes with a communication signal based on the IEEE 802.11a standard, On the other hand, a signal of 5 GHz band used for communication is allowed to pass through without passing through a low-pass filter process.

  By doing so, the transmission unit 32 of the wireless communication unit 31 performs communication according to the communication scheme based on the IEEE802.11b standard (when outputting a 2.4 GHz band signal). It is possible to attenuate the 2.4 GHz band harmonic component, which can be a disturbance signal of a 5 GHz band signal, which is a communication signal based on the standard, to a sufficiently low level, and to suppress the output of the interference wave for 5 GHz band communication. be able to. That is, the transmission unit 32 can reduce the manufacturing cost and the circuit scale without reducing the transmission performance.

  Conversely, in the case of reception processing, when a signal is transmitted from the outside of the wireless communication unit 31 and the antenna 46 receives it, the antenna 46 supplies the received signal to the switch circuit 45. In the following, it is assumed that the reception signal received by the antenna 46 includes both a 2.4 GHz band signal and a 5 GHz band signal. The low frequency component in the 5 GHz band is sufficiently small and does not affect the 2.4 GHz band signal.

  For example, when communication is performed using a communication method based on the IEEE802.11b standard using the 2.4 GHz band (when the received signal is a communication signal based on the IEEE802.11b standard), the switch circuit 45 is: The antenna 46 and the filter unit 47 are connected, and the acquired received signal is supplied to the filter unit 47.

  In this case, the reception control unit 52 supplies a control signal whose value is “0” to the filter unit 47 via the control bus 52A. Based on this control signal, the filter unit 47 operates as described above, and performs processing as a through circuit on the reception signal supplied from the switch circuit 45. That is, the filter unit 47 passes all the frequency bands (frequency bands including at least the 2.4 GHz band) of the supplied transmission signal, and supplies them to the broadband low noise amplifier 48 as they are.

  The broadband low noise amplifier 48 amplifies the supplied reception signal and supplies it to the diplexer circuit 49. The diplexer circuit 49 connects the output of the broadband low noise amplifier 48 to the 2.4 GHz band communication reception control unit 63, and outputs the output (amplified received signal) of the broadband low noise amplifier 48 to the 2.4 GHz band communication reception control unit 63. To supply. The reception control unit 63 for 2.4 GHz band communication of the reception control unit 52 that has acquired the reception signal extracts a 2.4 GHz band signal from the reception signal based on the IEEE802.11b standard, and extracts the 2.4 GHz band of the extracted signal. When the reception data is generated based on the band signal, the reception data is output to the outside of the wireless communication unit 31.

  In this case, as described above, the received signal includes both the 2.4 GHz band signal and the 5 GHz band signal, but the low frequency component of the 5 GHz band is sufficiently small, and the 2.4 GHz band signal Since it does not become an interference wave, the 2.4 GHz band communication reception control unit 63 normally extracts a 2.4 GHz band signal from the received signal, and generates reception data based on the extracted 2.4 GHz band signal. be able to.

  Further, for example, when communication is performed using a communication method based on the IEEE802.11a standard using the 5 GHz band (when the received signal is a communication signal based on the IEEE802.11a standard), the switch circuit 45 includes: The antenna 46 and the filter unit 47 are connected, and the acquired received signal is supplied to the filter unit 47.

  In this case, the reception control unit 52 supplies a control signal having a value “1” to the filter unit 47 via the control bus 52A. Based on this control signal, the filter unit 47 operates as described above, and performs high-pass filter processing on the received signal supplied from the switch circuit 45. That is, the filter unit 47 avoids unnecessary low-frequency components from the received signal so that a 2.4 GHz band harmonic component included in the received signal is not amplified when the received signal is amplified by the broadband low-noise amplifier 48 in the subsequent stage. For example, the signal is removed by blocking (or reducing) 2.4 GHz band, and the original 5 GHz band signal is extracted and supplied to the broadband low noise amplifier 48.

  The broadband low noise amplifier 48 amplifies the supplied reception signal and supplies it to the diplexer circuit 49. The diplexer circuit 49 connects the output of the broadband low noise amplifier 48 to the reception control unit 64 for 5 GHz band communication, and supplies the output (amplified received signal) of the broadband low noise amplifier 48 to the reception control unit 64 for 5 GHz band communication. The reception control unit 64 for 5 GHz band communication of the reception control unit 52 that has acquired the reception signal extracts a 5 GHz band signal from the received signal based on the IEEE802.11a standard, and receives data based on the extracted signal. The received data is output to the outside of the wireless communication unit 31.

  That is, when performing communication using a communication method based on the IEEE802.11a standard, the filter unit 47 performs high-pass filter processing on the received signal to pass a signal in the 5 GHz band used for communication, and generates harmonics. Blocks (or reduces) 2.4 GHz band signals that are based on the IEEE802.11b standard, which may interfere with signals in the 5 GHz band, and communicates using a communication system based on the IEEE802.11b standard. When performing, the received signal is directly passed through without performing a high-pass filter process, and a 2.4 GHz band signal used for communication is passed.

  By doing so, the receiving unit 33 of the wireless communication unit 31 has a higher harmonic component of 5 GHz when performing communication using a communication method based on the IEEE802.11a standard (when receiving a signal of 5 GHz band). The 2.4 GHz band frequency component, which is a communication signal based on the IEEE802.11b standard that may interfere with the band signal, can be attenuated to a sufficiently low level, and the interference wave to the 5 GHz band communication Generation (influence) can be suppressed. That is, the receiving unit 33 can reduce the manufacturing cost and the circuit scale.

  As described above, the wireless communication unit 31 includes the transmission unit 32 and the reception unit 33 as described above, and is based on the IEEE802.11a standard based on the communication signal based on the IEEE802.11b standard. Interference (interference) with communication signals can be suppressed by the communication method. That is, when performing a plurality of radio communications using different frequency bands, the radio communication unit 31 reduces the interference (interference) with other frequency bands while transmitting and receiving signals in the plurality of radio communications. The circuit can be shared. That is, the wireless communication unit 31 can reduce the manufacturing cost and the circuit scale.

  Next, the flow of transmission / reception processing by the wireless communication unit 31 in FIG. 2 will be described with reference to the flowcharts in FIGS. 9 and 10.

  First, the communication control unit 41 of the wireless communication unit 31 performs filter setting processing in step S1, and performs setting processing of the filter unit 44 and the filter unit 47 in accordance with the wireless communication method. Details of the setting process will be described later with reference to the flowchart of FIG.

  The communication control unit 41 that has performed the filter setting process proceeds to step S2 and determines whether to transmit data. When transmission data is supplied from the outside of the wireless communication unit 31 and when it is determined to transmit data because it is in a state of performing transmission processing, the transmission control unit 51 (2.4 GHz band of the transmission control unit 51) The communication transmission control unit 61 or the 5 GHz band communication transmission control unit 62) creates a transmission signal from the transmission data and supplies it to the diplexer circuit 42. In step S <b> 3, the diplexer circuit 42 selects a transmission signal to be supplied to the wideband power amplifier 43 based on the wireless communication method, and supplies the supplied transmission signal to the wideband power amplifier 43.

  The broadband power amplifier 43 supplied with the transmission signal amplifies the transmission signal and supplies it to the filter unit 44 in step S4. In step S5, the filter unit 44 supplied with the transmission signal determines whether or not the transmission signal is a low-frequency signal (2.4 GHz band signal), and the control supplied via the control bus 51A. If it is determined that the transmission signal is a low frequency signal (2.4 GHz band signal) based on the signal, in step S6, the high frequency that is the frequency band of the harmonic component of the transmission signal (near 4.8 GHz). The transmission signal whose frequency is limited is cut (or reduced) and supplied to the switch circuit 45.

  In Step S5, when it is determined that the transmission signal is a high-frequency signal (5 GHz band signal) based on the control signal supplied via the control bus 51A, the filter unit 44 performs processing in Step S6. And the transmission signal is supplied to the switch circuit 45 as it is.

  In step S <b> 7, the switch circuit 45 sets a transmission path, connects the filter unit 44 and the antenna 46, and supplies a transmission signal supplied from the filter unit 44 to the antenna 46. In step S8, the antenna 46 radiates the transmission signal supplied from the switch circuit 45 to the space and outputs it. After completing the process of step S8, the wireless communication unit 31 supplies the process to step S11 of FIG.

  If it is determined in step S2 of FIG. 9 that transmission data is not supplied or is not in the state of transmission processing and it is determined that data is not transmitted, the communication control unit 41 performs processing in steps S3 to S8. Is omitted, and the process proceeds to step S11 in FIG.

  The communication control unit 41 determines whether to receive data in step S11 of FIG. If it is determined that data is to be received because the reception process is being performed, the communication control unit 41 proceeds to step S12. In step S <b> 12, the antenna 46 receives the radio signal supplied by propagating through the space, and supplies the received signal to the switch circuit 45. In step S <b> 13, the switch circuit 45 sets a reception path and supplies the reception signal received via the antenna 46 to the filter unit 47.

  The filter unit 47 supplied with the received signal determines whether or not the received signal is a high frequency side signal (5 GHz band signal) in step S14, and based on the control signal supplied via the control bus 52A. If it is determined that the received signal is a high frequency side signal (5 GHz band signal), in step S15, the low frequency band that is the frequency band of the low frequency side signal (near 2.4 GHz) of the transmission signal is set. The reception signal that is blocked (or reduced) and frequency-limited is supplied to the wideband low noise amplifier 48.

  If it is determined in step S14 that the received signal is a low-frequency signal (2.4 GHz band signal) based on the control signal supplied via the control bus 52A, the filter unit 47 The process of S15 is omitted, and the received signal is supplied to the broadband low noise amplifier 48 as it is.

  The broadband low noise amplifier 48 that has acquired the received signal amplifies the received signal and supplies it to the diplexer circuit 49 in step S16. In step S17, the diplexer circuit 49 distributes the acquired reception signal. That is, the diplexer circuit 49 is based on the wireless communication system, and the reception control unit on the side corresponding to the reception signal in the frequency band of the 2.4 GHz band communication reception control unit 63 or the 5 GHz band communication reception control unit 64. The acquired reception signal is supplied to. The reception control unit 52 (the reception control unit 63 for 2.4 GHz band communication or the reception control unit 64 for 5 GHz band communication of the reception control unit 52) to which the reception signal is supplied receives the target frequency band (2.4 GHz) from the reception signal. Band or 5 GHz band) signal is extracted, reception data is created using the extracted signal, and is output to the outside of the wireless communication unit 31.

  The reception control part 52 which complete | finished the process of step S17 advances a process to step S18. If it is determined in step S11 that no data is received, the communication control unit 41 omits steps S12 to S17 and proceeds to step S18.

  In step S18, the communication control unit 41 determines whether to end the transmission / reception process. If the communication is not ended and it is determined not to end the transmission / reception process, the process returns to step S2 in FIG. The subsequent processing is repeated. If it is determined in step S18 that communication is completed and the transmission / reception process is terminated, the communication control unit 41 proceeds to step S19, performs the termination process, and then terminates the transmission / reception process.

  By performing the processing as described above, when the transmission unit 32 of the wireless communication unit 31 performs communication using a communication method based on the IEEE802.11b standard (when transmitting a signal of 2.4 GHz band), the 5 GHz band Output (influence) of interference waves in the communication of the wireless communication unit 31 and the reception unit 33 of the wireless communication unit 31 performs communication using a communication method based on the IEEE802.11a standard (a signal in the 5 GHz band). In the case of reception), it is possible to suppress the generation (influence) of interference waves on the communication in the 5 GHz band due to the signal component in the 2.4 GHz band. As a result, the wireless communication unit 31 can suppress interference (disturbance) with a communication signal based on the IEEE802.11a standard due to a communication signal based on the IEEE802.11b standard. That is, when performing a plurality of radio communications using different frequency bands, the radio communication unit 31 reduces the interference (interference) with other frequency bands while transmitting and receiving signals in the plurality of radio communications. The circuit can be shared. That is, the wireless communication unit 31 can reduce the manufacturing cost and the circuit scale.

  Next, details of the filter setting process executed in step S1 of FIG. 9 will be described with reference to the flowchart of FIG.

  First, in step S31, the communication control unit 41 determines whether to transmit / receive a low-frequency signal based on the setting of the communication method. That is, the communication control unit 41 determines whether or not to perform wireless communication based on IEEE802.11b using the 2.4 GHz band. When the 2.4 GHz band communication transmission control unit 61 and the 2.4 GHz band communication reception control unit 63 are used and the wireless communication unit 31 determines to transmit / receive a signal on the low frequency side of the corresponding dual band, the communication The control unit 41 proceeds with the process to step S32.

  In step S32, the communication control unit 41 controls the filter circuit 44 on the transmission side to operate as a low-pass filter. That is, in step S32, the transmission control unit 51 of the communication control unit 41 supplies a control signal having a value of “1” to the filter unit 44 via the control bus 51A, and causes the filter unit 44 to operate as a low-pass filter.

  When the process of step S32 ends, the communication control unit 41 controls the reception side filter circuit 47 to operate as a through circuit in step S33. That is, in step S33, the reception control unit 52 of the communication control unit 41 supplies a control signal having a value of “0” to the filter unit 47 via the control bus 52A, and connects the filter unit 47 to the through circuit (transmission line). To act as.

  The communication control unit 41 that has finished the process of step S33 advances the process to step S34. In Step S31, when it is determined that the low frequency signal is not transmitted / received, the communication control unit 41 omits Steps S32 and S33 and proceeds to Step S34.

  In step S34, the communication control unit 41 determines whether or not to transmit / receive a signal on the high frequency side based on the setting of the communication method. That is, the communication control unit 41 determines whether or not to perform wireless communication based on IEEE802.11a using the 5 GHz band. When it is determined that the radio communication unit 31 uses the 5 GHz band communication transmission control unit 62 and the 5 GHz band communication reception control unit 64 to transmit and receive a signal on the high frequency side of the dual band supported by the wireless communication unit 31, the communication control unit 41 The process proceeds to step S35.

  In step S35, the communication control unit 41 performs control so that the transmission-side filter circuit 44 operates as a through circuit. That is, in step S35, the transmission control unit 51 of the communication control unit 41 supplies a control signal having a value of “0” to the filter unit 44 via the control bus 51A, and the filter unit 44 is connected to the through circuit (transmission line). To act as.

  When the process of step S35 is completed, the communication control unit 41 controls the reception side filter circuit 47 to operate as a high-pass filter in step S36. That is, in step S36, the reception control unit 52 of the communication control unit 41 supplies a control signal having a value of “1” to the filter unit 47 via the control bus 52A, and causes the filter unit 47 to operate as a high-pass filter.

  The communication control unit 41 that has finished the process of step S36 advances the process to step S37. If it is determined in step S34 that the low frequency signal is not transmitted / received, the communication control unit 41 skips steps S35 and S36 and proceeds to step S37.

  In step S37, the communication control unit 41 determines whether or not the settings of the filter unit 44 and the filter unit 47 have been completed. If it is determined that the setting has not been completed, the communication control unit 41 returns the processing to step S31 and performs the subsequent processing. repeat. If it is determined in step S37 that the settings of the filter unit 44 and the filter unit 47 have been completed, the communication control unit 41 ends the filter setting process and returns the process to step S2 of FIG.

  By executing the filter setting process as described above, the communication control unit 41 allows the transmission unit 32 of the wireless communication unit 31 to perform communication using a communication method based on the IEEE802.11b standard (in the 2.4 GHz band). In the case of transmitting a signal), it is possible to suppress the output (influence) of the interference wave to the communication of 5 GHz band, and the receiving unit 33 of the wireless communication unit 31 is a communication method based on the IEEE802.11a standard. When communication is performed (when receiving a signal of 5 GHz band), it is possible to suppress the occurrence (influence) of interference waves on the communication of 5 GHz band due to the signal component of the 2.4 GHz band. That is, the communication control unit 41 causes the wireless communication unit 31 to suppress interference (disturbance) to a communication signal by a communication method based on the IEEE802.11a standard due to a communication signal based on the IEEE802.11b standard. Can be controlled. Thereby, when performing a plurality of wireless communication using different frequency bands, the wireless communication unit 31 reduces the interference (interference) with other frequency bands, while the transmission circuit and the The receiving circuit can be shared. That is, the wireless communication unit 31 can reduce the manufacturing cost and the circuit scale.

  The wireless communication unit 31 described above may be realized by only the wireless communication unit 31 as a wireless communication module. For example, the wireless communication unit 31 may be incorporated into an access point, a LAN card, a personal computer, a PDA, or the like to perform communication. Of course, it may be realized as a part of the apparatus.

  FIG. 12 is a diagram illustrating a configuration example of a communication apparatus to which the present invention is applied.

  In FIG. 12, a communication apparatus 150 is a device having a communication function such as an access point, a LAN card, a personal computer, or a PDA. The CPU 151 of the communication device 150 executes various processes in accordance with programs stored in the ROM 152. The RAM 153 appropriately stores data and programs necessary for the CPU 151 to execute various processes.

  The CPU 151, ROM 152, and RAM 153 are connected to each other via a bus 154. An input / output interface 160 is also connected to the bus 154.

  The input / output interface 160 is connected to an input unit 161 including, for example, various buttons, a remote controller, a keyboard, or a mouse, and outputs a signal input to the input unit 161 to the CPU 151. The input / output interface 160 is also connected to an output unit 162 including a display for displaying a GUI (Graphical User Interface), a status display LED (Light Emitting Diode), or a speaker.

  Further, the input / output interface 160 includes a storage unit 163 made up of a hard disk, EEPROM (Electronically Erasable and Programmable Read Only Memory), flash memory or the like for storing programs executed by the CPU 151, and a wired network. A wired communication unit 164 that is connected and performs data communication with other devices via the network is also connected.

  A drive 165 is appropriately connected to the input / output interface 160. The drive 165 is controlled by the CPU 151 and the like, and the program is executed by the removable medium 166 that is a recording medium such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory mounted on the drive 165, and the program is executed. Necessary data is read, and data and programs supplied from the CPU 151 and the like are written to the removable medium 166.

  Further, the above-described wireless communication unit 31 is connected to the input / output interface 160. As described above, the wireless communication unit 31 realizes connection to a network by wireless communication.

  The CPU 151 selects a wireless communication method to be used, such as IEEE802.11a or IEEE802.11b, based on a user instruction input from the input unit 161 or a program being executed, and controls the wireless communication unit 31. Then, wireless communication by the selected wireless communication method is executed. The wireless communication unit 31 performs transmission / reception processing as described above based on the control of the CPU 151.

  By doing so, the communication device 150 suppresses the interference (disturbance) with respect to the communication signal by the communication method based on the IEEE802.11a standard due to the communication signal based on the IEEE802.11b standard. Wireless communication can be performed. At this time, the wireless communication unit 31 reduces the interference (interference) with other frequency bands when performing a plurality of wireless communications using different frequency bands by performing the wireless communication process as described above. However, the transmission circuit and the reception circuit can be shared in the plurality of wireless communications. That is, the wireless communication unit 31 and the communication device 150 can reduce manufacturing costs and circuit scale.

  In the above description, when transmitting a 2.4 GHz band signal, the wireless communication unit 31 uses the filter unit 44 to remove the harmonic component of the 2.4 GHz band signal from the output of the broadband power amplifier 43. However, in addition to this, any configuration may be used as long as the harmonic component of the 2.4 GHz band signal can be removed. For example, instead of the filter unit 44 operating as a low-pass filter in FIG. A band reject filter that removes only a frequency component in the vicinity of 4.8 GHz, which is the frequency of the double component of the .4 GHz band signal, may be used.

  FIG. 13 is a diagram illustrating a configuration example of a band reject filter. In FIG. 13, the input terminal 71 and the output terminal 73 of the band reject filter 170 are respectively the output terminal of the broadband power amplifier 43 or the switch circuit 45, as in the case of the filter unit 44 described with reference to FIG. The terminal on which the filter unit 47 is connected is connected to a terminal different from the terminal to which the filter unit 47 is connected. In the case of FIG. 13, unlike the case of the filter unit 44 of FIG. 3, there is no input terminal connected to the control bus 51A to which the control signal is supplied from the transmission control unit 51. That is, this band reject filter 170 is 5 GHz output from the 5 GHz band communication transmission control unit 62 even in the case of the 2.4 GHz band transmission signal output from the 2.4 GHz band communication transmission control unit 61. Even in the case of a band transmission signal, it operates as a band reject filter. Therefore, in this case, the transmission control unit 62 for 5 GHz band communication transmits a signal using a frequency band different from the frequency band removed by the band reject filter 170 such as 5 GHz or more.

  In FIG. 13, between an input terminal 71 and an output terminal 173, an inductor 171 and a capacitor 181 connected in parallel, an inductor 172 and a capacitor 182 connected in parallel, and an inductor 173 and a capacitor 183 connected in parallel are connected. Are connected in series. One terminal of the inductor 191 is between the capacitors 181 and 182 (between the inductor 181 and the inductor 182), and between the capacitor 182 and the capacitor 183 (between the inductor 182 and the inductor 183). One terminal of the inductor 193 is connected to each other. Further, the other terminal of the inductor 191 is grounded via a capacitor 192, and the other terminal of the inductor 193 is grounded via a capacitor 194.

  The band reject filter 170 configured as described above has input / output characteristics as shown in FIG. 14, and blocks (or reduces) a signal having a frequency of about 4.8 GHz from the input transmission signal. To remove. Note that the input / output characteristics shown in FIG. 14 are merely examples, and may be other than those described above. For example, the band reject filter 170 may remove a plurality of frequency band components. In this input / output characteristic, it is desirable that the band reject filter 170 sharply lowers the gain only in the frequency band to be removed (in the case of FIG. 14, the frequency band near 4.8 GHz). As shown in FIG. 4, some other band components may be blocked (or reduced) as long as the characteristics do not affect the transmission signal.

  As described above, the use of the band reject filter 170 eliminates the need for the transmission control unit 51 to control the filter unit 44, so that the transmission unit 32 has a simpler circuit configuration and a larger circuit scale and manufacturing cost. Can be reduced. As a result, the wireless communication unit 31 performs the wireless communication process as described above to reduce interference with other frequency bands when performing a plurality of wireless communication using different frequency bands. Can do. That is, the wireless communication unit 31 and the communication device 150 can further reduce the manufacturing cost and the circuit scale.

  Of course, instead of the band reject filter that blocks (or reduces) only the predetermined frequency band component, a band pass filter that allows only the predetermined frequency band component to pass may be used. In this case, for example, when a signal is transmitted using the 2.4 GHz band communication transmission control unit 61, the bandpass filter is operated so as to pass only the frequency component of the 2.4 GHz band, and the transmission for 5 GHz band communication is performed. When transmitting a signal using the control part 62, it operates so that only the frequency component of 5 GHz band may be passed. In this way, only necessary frequency components can be extracted from the output of the wideband power amplifier 43, and interference with other frequency components can be suppressed.

  The frequency band of a signal to be blocked (or reduced) or passed through the above band reject filter or band pass filter may be fixed or variable. Further, as in the filter unit 44 of FIG. 3, a control unit may be provided in the band reject filter or the band pass filter so as to operate as a filter or as a through circuit depending on the frequency band of the transmission signal. Good.

  In the above, the wireless communication unit 31 has been described as performing wireless communication based on the wireless LAN communication standards of IEEE802.11a and IEEE802.11b, that is, wireless communication using the 2.4 GHz band or the 5 GHz band. However, the wireless communication method may be any method, and the frequency band used for these wireless communication may be any frequency band as long as it uses different frequency bands. It may be.

  In the above description, the wireless communication unit 31 has been described so as to suppress interference (disturbance) with respect to a transmission / reception signal in the 5 GHz band due to a harmonic component included in the transmission / reception signal in the 2.4 GHz band. For example, interference (interference) with respect to signals in other frequency bands such as suppression of interference (interference) with respect to 2.4 GHz band transmission / reception signals due to subharmonic components included in transmission / reception signals in 5 GHz band may be suppressed. That's fine.

  Furthermore, the wireless communication unit 31 may be configured to output three types of transmission signals based on three or more standards using different frequency bands based on different standards. In this case, the wireless communication unit 31 may use a band reject filter, a band pass filter, or the like as shown in FIG. 13 instead of the filter unit 44, or a combination of a low pass filter and a high pass filter. It may be.

  The same applies to the filter unit 47 of the reception unit 33, and a band reject filter or a band pass filter may be used instead of the filter unit 47.

  In the wireless communication unit 31 shown in FIG. 2, it has been described that the transmission unit 32 is provided with the filter unit 44 and the reception unit 33 is further provided with the filter unit 47. Only the filter unit 44 may be provided, and the filter unit 47 of FIG. 2 may be omitted.

  FIG. 15 is a block diagram showing another configuration example of the wireless communication unit to which the present invention is applied. In FIG. 15, the wireless communication unit 201 has basically the same configuration as the wireless communication unit 31 of FIG. 2. Like the wireless communication unit 31, the wireless communication unit 201 transmits and receives 2.4 GHz band signals and 5 GHz band signals. Is a dual-band communication unit that transmits and receives. As in the case of the wireless communication unit 31 of FIG. 2, the transmission unit 32 of the wireless communication unit 201 is provided with a filter unit 44 after the broadband power amplifier 43, but the reception unit 213 is the reception unit of FIG. Unlike the case of 33, the filter unit 47 is not provided, and the reception signal output from the switch circuit 45 is supplied to the broadband low noise amplifier 48.

  That is, the wireless communication unit 201 has a configuration in which the filter unit 47 is omitted from the wireless communication unit 31. By doing so, the wireless communication unit 201 cannot remove (or reduce) the harmonic component of the 2.4 GHz band signal included in the received signal, but the 2.4 GHz band included in the transmission signal. The harmonic components of the signal can be removed (or reduced), and the manufacturing cost and circuit scale can be further reduced as compared with the wireless communication unit 31 because the filter unit 47 is omitted. That is, the wireless communication unit 201 is inferior to the wireless communication unit 31 in terms of the ability to remove interference waves (unnecessary harmonic components and subharmonic components), but the manufacturing cost and circuit scale can be further reduced accordingly. Therefore, for example, when the ratio of the interference wave included in the reception signal is small and it is not necessary to remove (or reduce) the interference wave in the reception unit 33, such a wireless communication unit 201 (reception unit 213) is applied. Thus, not only can interference waves be sufficiently removed in wireless communication, but also the manufacturing cost and circuit scale of the wireless communication unit can be further reduced.

  Conversely, the filter unit 47 may be provided only in the receiving unit 33 and the filter unit 44 in FIG. 2 may be omitted.

  FIG. 16 is a block diagram showing still another configuration example of the wireless communication unit to which the present invention is applied. In FIG. 16, the wireless communication unit 221 basically has the same configuration as the wireless communication unit 31 in FIG. 2. Like the wireless communication unit 31, the wireless communication unit 221 transmits and receives 2.4 GHz band signals and 5 GHz band signals. Is a dual-band communication unit that transmits and receives. As in the case of the wireless communication unit 31 in FIG. 2, the reception unit 33 of the wireless communication unit 221 is provided with the filter unit 47 after the switch circuit 45, but the transmission unit 222 is the transmission unit 32 of FIG. Unlike the case, the transmission signal output from the broadband power amplifier 43 without the filter unit 44 is supplied to the switch circuit 45.

  That is, the wireless communication unit 221 has a configuration in which the filter unit 44 is omitted from the wireless communication unit 31. By doing so, the wireless communication unit 221 cannot remove (or reduce) the harmonic component of the 2.4 GHz band signal included in the transmission signal, but the 2.4 GHz band included in the reception signal. The harmonic components of the signal can be removed (or reduced), and the manufacturing cost and circuit scale can be further reduced as compared with the wireless communication unit 31 because the filter unit 44 is omitted. That is, the wireless communication unit 221 is inferior to the wireless communication unit 31 in terms of the ability to remove interfering waves (unnecessary harmonic components and subharmonic components), but the manufacturing cost and circuit scale can be further reduced accordingly. Therefore, for example, when the ratio of the interference wave included in the transmission signal is small and it is not necessary to remove (or reduce) the interference wave in the transmission unit 32, the wireless communication unit 221 can be used in wireless communication. Not only can the interference wave be sufficiently removed, but also the manufacturing cost and circuit scale of the wireless communication unit can be further reduced.

  In FIG. 2, the wireless communication unit 31 has been described as outputting a transmission signal using one antenna 46 and receiving a reception signal. However, for example, as shown in FIG. You may make it use.

  17, the wireless communication unit 231 has basically the same configuration as the wireless communication unit 31 in FIG. 2, but instead of the switch circuit 45, two SPDT (Single Pole Double Throw) switches connected in series are used. A circuit 241 and an SPDT switch circuit 242 are provided, and two antennas 243 and 244 are connected to the SPDT switch circuit 242 as a diversity antenna.

  That is, at the time of transmission, the SPDT switch circuit 241 connects the filter unit 44 to the SPDT switch circuit 242, and the SPDT switch circuit 242 connects the SPDT switch circuit 241 to the antenna 243 or the antenna 244. 243 or the antenna 244. At the time of reception, the SPDT switch circuit 242 connects the antenna 243 or 244 to the SPDT switch circuit 241, and the SPDT switch circuit 241 connects the SPDT switch circuit 242 to the filter unit 47, so that reception is performed at the antenna 243 or antenna 244. The received signal is supplied to the filter unit 47.

  Accordingly, the wireless communication unit 231 includes the transmission unit 232 including the SPDT switch circuit 241, the SPDT switch circuit 242, the antenna 243, and the antenna 244, and the reception including the SPDT switch circuit 241, the SPDT switch circuit 242, the antenna 243, and the antenna 244. Part 233.

  In FIG. 17, the wireless communication unit 231 has been described as configured by the transmission unit 232 and the reception unit 233 including the two SPDT switch circuits 241 and the SPDT switch circuit 242, but not limited thereto, for example, Of course, the two SPDT switch circuits 241 and the SPDT switch circuit 242 may be configured by one DPDT switch circuit (Double Pole Double Throw).

  In the above, the processing in wireless communication has been described. However, as long as a plurality of communications using carrier waves having different frequencies are performed, the communication medium may be wireless or wired. In that case, for example, in the wireless communication unit 31 of FIG. 2 (in this case, a wired communication unit), instead of the antenna 46, a cable (transmission line) connected to the communication unit of another device is provided.

  The series of processes described above can be executed by hardware, or can be executed by software as described above. When a series of processing is executed by software, various functions can be executed by installing a computer in which the programs that make up the software are installed in dedicated hardware, or by installing various programs. For example, it is installed from a recording medium or the like into a general-purpose personal computer or the like.

  For example, as shown in FIG. 12, the recording medium is distributed to provide a program to the user separately from the computer, and includes a magnetic disk (including a flexible disk) on which the program is recorded, an optical disk (CD- ROM (Compact Disc-Read Only Memory), CD-R (Compact Disc-Recordable), CD-RW (Compact Disc-ReWritable), DVD-ROM (Digital Versatile Disc-Read Only Memory), DVD-RAM (Digital Versatile Disc) -Random Access Memory), DVD-R (Digital Versatile Disc-Recordable), DVD-RW (Digital Versatile Disc-ReWritable), DVD + R (Digital Versatile Disc + Recordable), DVD + RW (Digital Versatile Disc + ReWritable) In addition to a removable medium 346 including a package medium made of a semiconductor memory or the like. Is provided to the user until a state, the program is composed of a hard disk that contain or ROM152 is stored the storage unit 163.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

  Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

It is a block diagram which shows the structural example of the conventional radio | wireless communication apparatus. It is a block diagram which shows the structural example of the radio | wireless communication part to which this invention is applied. It is a block diagram which shows the structural example of the filter part of FIG. It is a figure which shows the example of the input-output characteristic of the filter part of FIG. It is a figure which shows the other example of the input-output characteristic of the filter part of FIG. It is a block diagram which shows the structural example of the filter part of FIG. It is a figure which shows the example of the input-output characteristic of the filter part of FIG. It is a figure which shows the other example of the input-output characteristic of the filter part of FIG. It is a flowchart explaining the example of a transmission / reception process. FIG. 10 is a flowchart illustrating an example of transmission / reception processing, following FIG. 9. It is a flowchart explaining the example of the detail of a filter setting process. It is a figure which shows the structural example of the communication apparatus to which this invention is applied. It is a figure which shows the structural example of a band rejection filter. It is a figure which shows the example of the input / output characteristic of the band reject filter of FIG. It is a block diagram which shows the other structural example of the radio | wireless communication part to which this invention is applied. It is a block diagram which shows the further another structural example of the radio | wireless communication part to which this invention is applied. It is a block diagram which shows the further another structural example of the radio | wireless communication part to which this invention is applied.

Explanation of symbols

  1 wireless communication device, 31 wireless communication unit, 32 transmission unit, 33 reception unit, 41 communication control unit, 42 diplexer circuit, 43 broadband power amplifier, 44 filter unit, 45 switch circuit, 46 antenna, 47 filter unit, 48 broadband low noise Amplifier, 49 Diplexer circuit, 51 Transmission control unit, 52 Reception control unit, 61 2.4 GHz band communication transmission control unit, 62 5 GHz band communication transmission control unit, 63 2.4 GHz band communication reception control unit, 64 5 GHz band Reception control unit for communication, 72 filter processing unit, 75 control unit, 102 filter unit, 105 control unit, 150 communication device, 151 CPU, 170 band reject filter, 201 wireless communication unit, 213 reception unit, 221 wireless communication unit, 231 Wireless communication unit , 233 receiver, 241 SPDT switch circuit, 242 SPDT switch circuit, 243 antenna, 244 antenna

Claims (25)

Signal of the first frequency band, and, in the transmitting and receiving apparatus for transmitting and receiving signals of the first of the second frequency band is a band of high frequency than the frequency band,
Generating means for processing transmission data and generating a transmission signal of the first frequency band or the second frequency band ;
First amplification means for amplifying the transmission signal generated by the generation means ;
When the transmission signal amplified by the first amplifying means is a signal in the first frequency band, a first filtering process for blocking or reducing a frequency component of a predetermined frequency or higher with respect to the transmission signal is performed. By performing, the frequency component of the first frequency band of the transmission signal is allowed to pass, and the frequency component of the second frequency band is blocked or reduced, and the transmission signal is a signal of the second frequency band. The first filter means for passing the transmission signal without performing the first filter processing ;
Transmitting means for transmitting the transmission signal of the frequency component that has been passed through the first filter processing by the first filter means or passed without being performed;
Receiving means for receiving a signal in the first frequency band or the second frequency band ;
When receiving a signal of the second frequency band, the received signal is obtained by performing a second filtering process for blocking or reducing a frequency component equal to or lower than a predetermined frequency with respect to the received signal received by the receiving unit. When the signal of the first frequency band is received while the frequency component of the second frequency band is allowed to pass and the frequency component of the first frequency band is blocked or reduced, the received signal is Second filter means for passing without performing second filter processing ;
A second amplifying means for amplifying the received signal of the frequency component that has been passed or not passed through the second filter processing by the second filter means;
Extracting means for extracting received data from the received signal amplified by the second amplifying means;
A transmission / reception device comprising: When the transmission signal is a signal in the first frequency band, the first filter means blocks or reduces a frequency component of the transmission signal that becomes an interference wave of the signal in the second frequency band. The first filtering process is performed on
The transmission / reception apparatus according to claim 1 . The first filter means includes
A predetermined low-pass filter circuit;
By controlling the grounding of the low-pass filter circuit, the low-pass filter circuit is operated as a low-pass filter that performs the first filter processing or a through circuit that passes without performing the first filter processing. The transmission / reception apparatus according to claim 1, further comprising: a control unit that controls. The low-pass filter circuit includes a first inductor, a second inductor, and a first capacitor. One terminal of the first inductor is connected to the first amplifying means, and the other terminal is the first terminal. Two inductors and one terminal of the capacitor, the other terminal of the second inductor is connected to the transmitting means,
The transmission / reception apparatus according to claim 3, wherein the control unit controls grounding of the other terminal of the first capacitor. When the transmission signal is a signal in the first frequency band, the control means grounds the other terminal of the first capacitor, operates the low-pass filter circuit as the low-pass filter, and transmits the transmission signal. 5. The transmission / reception device according to claim 4, wherein when the signal is a signal in the second frequency band, the other terminal of the first capacitor is opened, and the low-pass filter circuit is operated as the through circuit. The control means grounds the other terminal of the first capacitor via a diode, and when the transmission signal is a signal in the first frequency band, by causing a current to flow through the diode, When the other terminal of one capacitor is grounded and the transmission signal is a signal in the second frequency band, the other terminal of the first capacitor is opened by not passing a current through the diode. The transmission / reception apparatus according to claim 5. The control means includes a third inductor, a second capacitor, and a resistor in addition to the diode, and one terminal of the resistor is connected to an input terminal to which a control signal is input, and the other of the resistors Is connected to one terminal of the third inductor and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is connected to the other terminal of the third inductor. The terminal is connected to the other terminal of the first capacitor and the anode of the diode, the cathode of the diode is grounded, and the first signal is input based on the value of the control signal input to the input terminal. The transmission / reception apparatus according to claim 6, wherein grounding of the other terminal of the capacitor is controlled. The second filter means includes
A predetermined high-pass filter circuit;
By controlling the grounding of the high-pass filter circuit, the high-pass filter circuit is operated as a high-pass filter that performs the second filter process or a through circuit that passes without performing the second filter process. The transmission / reception apparatus according to claim 1, further comprising: a control unit that controls. The high-pass filter circuit includes a first capacitor, a first inductor, and a second inductor, and one terminal of the first capacitor is connected to the receiving means and one terminal of the first inductor. The other terminal of the first capacitor is connected to the second amplifying means and one terminal of the second inductor,
The transmission / reception apparatus according to claim 8, wherein the control unit controls grounding of the other terminal of the first inductor and the second inductor. The control means, when receiving a signal of the second frequency band, grounds the other terminal of the first inductor and the second inductor, and operates the high-pass filter circuit as the high-pass filter, The transmission / reception according to claim 9, wherein when receiving a signal in the first frequency band, the other terminal of the first inductor and the second inductor is opened, and the high-pass filter circuit is operated as the through circuit. apparatus. When the control means grounds the other terminal of the first inductor and the second inductor via a diode and receives a signal of the second frequency band, it causes a current to flow through the diode. , When receiving the signal of the first frequency band by grounding the other terminal of the first inductor and the second inductor, by passing no current through the diode, the first inductor and the The transmission / reception apparatus according to claim 10, wherein the other terminal of the second inductor is opened. The control means includes a third inductor, a second capacitor, and a resistor in addition to the diode, and one terminal of the resistor is connected to an input terminal to which a control signal is input, and the other of the resistors Is connected to one terminal of the third inductor and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is connected to the other terminal of the third inductor. The terminal is connected to the other terminal of the first inductor and the second inductor and the anode of the diode, the cathode of the diode is grounded, and the value of the control signal input to the input terminal The transmission / reception apparatus according to claim 11, wherein grounding of the other terminal of the first inductor and the second inductor is controlled based on the first inductor. Signal of the first frequency band, and, in the transmission apparatus for transmitting a signal of the second frequency band is the band of the high frequency than said first frequency band,
Generating means for processing transmission data and generating a transmission signal of the first frequency band or the second frequency band ;
Amplifying means for amplifying the transmission signal generated by the generating means ;
When the transmission signal amplified by the amplifying means is a signal in the first frequency band, the transmission signal is subjected to a filtering process for blocking or reducing a frequency component of a predetermined frequency or higher with respect to the transmission signal. When the frequency component of the first frequency band of the signal is allowed to pass and the frequency component of the second frequency band is blocked or reduced, and the transmission signal is the signal of the second frequency band, the transmission Filter means for passing the signal without performing the filtering process ;
Transmitting means for transmitting the transmission signal of the frequency component that has been passed through with or without being subjected to the filtering process by the filtering means;
A transmission apparatus comprising: When the transmission signal is a signal in the first frequency band , the filter means is configured to block or reduce a frequency component of the transmission signal that becomes an interference wave of the signal in the second frequency band. Process
The transmission device according to claim 13 . The first filter means includes
A predetermined low-pass filter circuit;
Control means for controlling the grounding of the low-pass filter circuit to operate the low-pass filter circuit as a low-pass filter that performs the filtering process or a through circuit that passes without performing the filtering process. The transmission apparatus according to claim 13 . The low-pass filter circuit includes a first inductor, a second inductor, and a first capacitor. One terminal of the first inductor is connected to the first amplifying means, and the other terminal is the first terminal. Two inductors and one terminal of the capacitor, the other terminal of the second inductor is connected to the transmitting means,
The transmission device according to claim 15, wherein the control unit controls grounding of the other terminal of the first capacitor. When the transmission signal is a signal in the first frequency band, the control means grounds the other terminal of the first capacitor, operates the low-pass filter circuit as the low-pass filter, and transmits the transmission signal. Is the signal in the second frequency band, the other terminal of the first capacitor is opened, and the low-pass filter circuit is operated as the through circuit.
The transmission device according to claim 16 . The control means grounds the other terminal of the first capacitor via a diode, and when the transmission signal is a signal in the first frequency band, by causing a current to flow through the diode, When the other terminal of one capacitor is grounded and the transmission signal is a signal in the second frequency band, the other terminal of the first capacitor is opened by not passing a current through the diode.
The transmission device according to claim 17 . The control means includes a third inductor, a second capacitor, and a resistor in addition to the diode, and one terminal of the resistor is connected to an input terminal to which a control signal is input, and the other of the resistors Is connected to one terminal of the third inductor and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is connected to the other terminal of the third inductor. The terminal is connected to the other terminal of the first capacitor and the anode of the diode, the cathode of the diode is grounded, and the first signal is input based on the value of the control signal input to the input terminal. Control the grounding of the other terminal of the capacitor
The transmission device according to claim 18 . Signal of the first frequency band, and, in a receiving apparatus that receives signals of the second frequency band is the band of the high frequency than said first frequency band,
Receiving means for receiving a signal in the first frequency band or the second frequency band ;
When receiving the signal in the second frequency band, the received signal received by the receiving unit is subjected to filter processing for blocking or reducing a frequency component equal to or lower than a predetermined frequency. When the frequency component of the second frequency band is allowed to pass and the frequency component of the first frequency band is blocked or reduced, and the signal of the first frequency band is received, the received signal is subjected to the filtering process. Filter means to pass without performing ,
Amplifying means for amplifying the received signal of the frequency component that has been passed by the filter means with or without being filtered;
Extracting means for extracting received data from the received signal amplified by the second amplifying means;
A receiving device. The filter means includes
A predetermined high-pass filter circuit;
Control means for controlling the high-pass filter circuit to operate as a high-pass filter that performs the filtering process or a through circuit that passes without performing the filtering process by controlling grounding of the high-pass filter circuit. The receiving device according to claim 20 . The high-pass filter circuit includes a first capacitor, a first inductor, and a second inductor, and one terminal of the first capacitor is connected to the receiving means and one terminal of the first inductor. The other terminal of the first capacitor is connected to the second amplifying means and one terminal of the second inductor,
The control means controls grounding of the other terminal of the first inductor and the second inductor.
The receiving device according to claim 21 . The control means, when receiving a signal of the second frequency band, grounds the other terminal of the first inductor and the second inductor, and operates the high-pass filter circuit as the high-pass filter, When receiving the signal of the first frequency band, the other terminal of the first inductor and the second inductor is opened, and the high-pass filter circuit is operated as the through circuit.
The receiving device according to claim 22 . When the control means grounds the other terminal of the first inductor and the second inductor via a diode and receives a signal of the second frequency band, it causes a current to flow through the diode. , When receiving the signal of the first frequency band by grounding the other terminal of the first inductor and the second inductor, by passing no current through the diode, the first inductor and the Open the other terminal of the second inductor
The receiving device according to claim 23 . The control means includes a third inductor, a second capacitor, and a resistor in addition to the diode, and one terminal of the resistor is connected to an input terminal to which a control signal is input, and the other of the resistors Is connected to one terminal of the third inductor and one terminal of the second capacitor, the other terminal of the second capacitor is grounded, and the other terminal of the third inductor is connected to the other terminal of the third inductor. The terminal is connected to the other terminal of the first inductor and the second inductor and the anode of the diode, the cathode of the diode is grounded, and the value of the control signal input to the input terminal Based on this, the ground of the other terminal of the first inductor and the second inductor is controlled.
The receiving device according to claim 24 .

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