JP2005079634A - Wireless communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus compatible with multi-band that realizes less size and weight. <P>SOLUTION: A reception circuit 14 and a transmission circuit 24 are formed to be operative to signals at a 2.4 to 2.625 GHz band, when the signal at 5.2 GHz band is received, a straight / frequency divider circuit 12 applies 1/2 frequency division to a received signal, converts the signal into a signal with a 2.575 to 2.625 GHz band slightly higher than the 2.4 GHz band, and the reception circuit 14 converts the signal into an intermediate frequency signal IF. In the case of carrying out data transmission at a 5.2 GHz band, the intermediate frequency signal IF comprising the transmission data is fed to the transmission circuit 24, wherein the signal is converted into a signal with a 2.575 to 2.625 GHz band, a straight / multiplication circuit 22 multiplies the converted signal by a multiple of 2 to convert the signal into a signal with the 5.2 GHz band, and thereafter the resulting signal is transmitted via a transmission antenna 20. In the case of transmission / reception of a signal with the 2.4 GHz band, no frequency conversion by the straight / frequency divider circuit 12 and the straight / multiplication circuit 22 is executed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wireless communication device used in a wireless communication system, and more particularly to a wireless communication device capable of supporting a plurality of frequency bands with a simple configuration.

In recent years, with the development of various devices using wireless communication technology, there is an increasing demand for wireless communication devices that can be used in a plurality of wireless communication systems, so-called multi-mode wireless communication devices.
As such a multimode wireless communication apparatus, for example, as shown in FIG. 5, low noise amplifiers (LNA) 51a and 51b and power amplifiers (PA) 53a and 53b are arranged in frequency bands corresponding to the respective wireless communication systems. Any of the transmission signals from the duplexer 57 and the power amplifiers 53a and 53b for supplying the reception signal received by the reception antenna 55 to one of the low noise amplifiers 51a and 51b according to the frequency band. A duplexer 58 for outputting either of them to the transmission antenna 56 is provided.

  A voltage controlled oscillator (OSC) 63 that outputs a local oscillation signal, a mixer (MIX) 65 that converts the received signal into an intermediate frequency signal IF using the local oscillation signal, and filters the intermediate frequency signal IF from the mixer 65 A band pass filter (BPF) 66 that processes and outputs to the base band signal processing unit 70, a band pass filter 71 that filters an intermediate frequency signal IF composed of transmission data from the base band signal processing unit 70, and the local oscillation signal. The mixer 72 used for conversion to a predetermined transmission frequency is shared in each frequency band, and is switched between the low noise amplifiers 51a and 51b and the mixer 65, and between the mixer 72 and the power amplifiers 53a and 53b. 73 and 74 are inserted, and switched according to the frequency band corresponding to the wireless communication system. Switching the switches 73 and 74, low noise amplifier 51a, 51b and the power amplifier 53a, by switching 53b, that so as to realize the multi-mode wireless communication device is proposed.

For the purpose of downsizing the device, for example, when the local oscillation signal and the intermediate frequency signal IF from the voltage controlled oscillator are mixed, the frequency components of the sum and difference of the local oscillation signal and the intermediate frequency signal are obtained at the output. By utilizing this, a front end corresponding to two different radio frequency bands (see, for example, Patent Document 1), a front end is provided for each frequency band, and radio waves in a plurality of frequency bands are individually transmitted to the front end. So that the necessary band is selected and processed (for example, refer to Patent Document 2), and the devices constituting the transmitter and the receiver are shared. (For example, refer patent document 3) etc. are proposed.
JP-A-10-32519 JP 2002-335177 A JP 2003-18038 A

  However, as described in the above-mentioned Patent Document 1, for example, by utilizing the fact that the frequency components of the sum and difference of the intermediate frequency signal and the local oscillation signal can be obtained at the output, two different radio frequency bands are supported. When the method is used, there is only one low-noise amplifier or power amplifier on the circuit. However, since this single low-noise amplifier and power amplifier are applied to each band, a band-pass filter is required and an additional high-frequency switching switch and distributor are required. There is a problem that the point is insufficient and the insertion loss increases.

  In addition, as described in the above-mentioned Patent Document 2, radio waves in a plurality of frequency bands are received by separate front ends, multiplexed on the IF frequency band, and a necessary band is selected and processed. In this case, since the front end is required by the number of frequency bands, this case is also not efficient in terms of downsizing of the apparatus. Furthermore, as described in the above-mentioned Patent Document 3, when the circuit portion of the transmission unit and the reception unit is shared, the shared circuit has characteristics that satisfy both transmission and reception performance. The circuit design is complicated and leads to an increase in cost. In this case, an additional switch for switching between transmission and reception is required, the insertion loss increases, and the wiring is complicated. There is a problem of becoming.

  Accordingly, the present invention has been made paying attention to the above-mentioned conventional unsolved problems, and an object thereof is to provide a multiband-compatible radio communication device capable of reducing the size and weight of the device. Yes.

  To achieve the above object, according to the first aspect of the present invention, in a wireless communication apparatus including a wireless transmission circuit and a wireless reception circuit capable of wireless transmission / reception in a preset operable radio frequency band, a reception signal from a wireless antenna is transmitted. A reception frequency variable means capable of converting a radio reception frequency into a frequency within the operable radio frequency band, and a transmission frequency of an output signal to the radio antenna output from the radio transmission circuit is a frequency in a desired radio frequency band. At least one of the transmission frequency variable means that can be converted into a frequency, and when performing radio transmission / reception in a radio frequency band outside the operable radio frequency band, frequency conversion by the reception frequency variable means and the transmission frequency variable means is performed. It is characterized by what I did.

In the first invention, the reception frequency variable means capable of converting the radio reception frequency of the received signal from the radio antenna into a frequency within the operable radio frequency band of the radio reception circuit, and the radio antenna output from the radio transmission circuit At least one of transmission frequency variable means capable of converting the transmission frequency of the output signal to the frequency of a desired radio frequency band.
Therefore, when performing radio communication in a radio communication system of a certain radio frequency band, if this radio frequency band is outside the operable radio frequency band, by performing frequency conversion by the reception frequency variable means, The receiving circuit can operate with respect to signals in the radio frequency band. Further, the transmission signal of the frequency of the operable radio frequency band from the transmission circuit is converted into a frequency within a radio frequency band of a radio communication system for performing radio communication by the transmission frequency variable means, and this is converted via a transmission antenna. Wireless transmission can be performed.

  Similarly, when performing wireless communication in another wireless communication system, if necessary, the received signal is frequency-converted to the operable frequency band by the reception frequency variable means and processed by the reception circuit, A radio that can perform radio communication in different radio frequency bands by converting a transmission signal of an operable radio frequency band from a transmission circuit into a radio frequency band in the radio communication system by the transmission frequency variable means. A communication device can be realized. At this time, in a normal wireless communication apparatus provided with a receiving apparatus and a transmitting apparatus, it can be realized simply by providing a receiving frequency variable means or a transmitting frequency variable means, so that it is realized without significantly increasing the scale of the apparatus. be able to.

  In the second invention, the reception frequency variable means and the transmission frequency variable means include a multiplier circuit or a frequency divider circuit, and for each of a plurality of radio frequency bands to be communicated, the radio frequency band and the frequency divider are divided. Any one of the converted frequency bands when the frequency is multiplied or multiplied is included as a representative, and all the representative radio frequency bands or converted frequency bands when the representatives of the respective radio frequency bands to be communicated are located in a nearby band are included. The range is set as the operable radio frequency band.

In the second aspect of the invention, the reception frequency varying means and the transmission frequency varying means include a multiplier circuit or a frequency divider circuit.
For each of a plurality of radio frequency bands to be communicated, a representative of the radio frequency band and a converted frequency band when frequency conversion is performed by dividing or multiplying the frequency band, and a representative of the radio frequency band of each communication target When they are located in a closer band, a range including all the representative radio frequency bands or converted frequency bands at this time is set as an operable radio frequency band.

Therefore, the radio frequency bandwidth necessary for operation with respect to each radio frequency band to be communicated or the converted frequency band obtained by multiplying or dividing the radio frequency band, that is, the operable radio frequency bandwidth is set to be narrower. Can do.
In the third invention, the reception frequency varying means and the transmission frequency varying means operate in one of a frequency conversion mode for performing frequency conversion on an input signal and a non-frequency conversion mode. It is said.

In the third aspect of the invention, the reception frequency varying means and the transmission frequency varying means operate in any one of a frequency conversion mode for performing frequency conversion on an input signal and a non-frequency conversion mode.
Therefore, the reception is performed such that the conversion frequency band when the other radio frequency band is multiplied or divided is in the vicinity of the reference radio frequency band with any one of the plurality of radio frequency bands to be communicated as a reference. By performing frequency conversion using the frequency variable means and the transmission frequency variable means, the frequency band that can be processed by the receiving apparatus and the transmitting apparatus is greatly increased compared to the existing wireless communication apparatus that can operate in the reference wireless frequency band. A wireless communication device that can operate with respect to a plurality of wireless frequency bands can be realized without change.

In the fourth invention, the radio frequency band to be communicated is a radio frequency band of 5.2 GHz band and a radio frequency band of 2.4 GHz band, and the operable frequency band is 2.4000-2. .625 GHz band or 4.8 to 5.25 GHz band.
According to the fourth aspect of the present invention, it is possible to reduce the size and cost of a wireless communication device that can use a radio frequency band of 5.2 GHz band and a radio frequency band of 2.4 GHz band.

Embodiments of the present invention will be described below.
First, a first embodiment will be described.
FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a wireless communication apparatus, which is wireless in two types of radio frequency bands, a 2.4 GHz band and a 5.2 GHz band. It is configured as a wireless communication device capable of communication.

  This wireless communication device 100 includes a straight / frequency divider circuit 12 connected to the receiving antenna 10 and a wider bandwidth than the 2.4 GHz band connected to the output side of the straight / frequency divider circuit 12. A receiving circuit 14 capable of processing a signal in a radio frequency band of 400 to 2.625 GHz, a straight / multiplier circuit 22 connected to the transmitting antenna 20, and 2 connected to the input side of the straight / multiplier circuit 22 A transmission circuit 24 capable of processing a signal in a radio frequency band of 2.400 to 2.625 GHz having a wider bandwidth than the .4 GHz band, a voltage controlled oscillator (OSC) 30 for generating a local oscillation signal, The baseband signal processing unit 50 is connected to the receiving circuit 14 and the transmitting circuit 24 and performs modulation / demodulation of the received data and the transmitted data. Oscillator 30 is variably formed the oscillation frequency of the local oscillation signal by the baseband signal processing section 50.

  The straight / frequency divider circuit 12 includes, for example, a known frequency divider circuit, and operates in either a straight mode or a frequency conversion mode according to a mode signal from the baseband signal processing unit 50. When the straight mode is instructed, the received signal is output to the receiving circuit 14 as it is, and when the frequency conversion mode is instructed, the frequency of the received signal is divided (for example, 1/2), Output to the receiving circuit 14.

  The receiving circuit 14 is, for example, a low noise amplifier (LNA) 15 that amplifies the output signal of the straight / divider circuit 12 and a local oscillation that receives the output signal of the low noise amplifier 15 from the voltage controlled oscillator 30. A mixer (MIX) 17 that downconverts the signal to a predetermined intermediate frequency signal IF having a predetermined frequency, and a bandpass filter (BPF) 19 that filters the intermediate frequency signal IF output from the mixer 17. The filter output of the bandpass filter 19 is input to the baseband signal processing unit 50.

  On the other hand, the transmission circuit 24 receives an intermediate frequency signal IF composed of transmission data from the baseband signal processing unit 50 and filters the bandpass filter (BPF) 25, and the filter output of the bandpass filter 25. Is composed of a mixer (MIX) 27 for up-conversion using a local oscillation signal input from the voltage-controlled oscillator 30, and a power amplifier (PA) 29 for amplifying the output signal of the mixer 27. 29 output is input to the straight / multiplication circuit 22 as transmission data.

  The straight / multiplier circuit includes, for example, a known multiplier circuit, and operates in one of a straight mode and a frequency conversion mode according to a mode signal from the baseband signal processing unit 50. When the straight mode is instructed, the supplied transmission data is output to the transmission antenna 20 as it is. When the frequency conversion mode is instructed, the frequency of the supplied transmission data is multiplied (for example, doubled) and then output to the transmission antenna 20.

  The baseband signal processing unit 50 constitutes a modulation / demodulation unit. When transmission data is input from a host device (not shown) or the like, the baseband signal processing unit 50 modulates the transmission data at a high transmission rate and converts it into an intermediate frequency signal of about several hundred MHz. Is output to the transmission circuit 24, and when an intermediate frequency signal is input from the reception circuit 14, it is demodulated and transmitted as received data to a host device or the like. Here, OFDM (Orthogonal Frequency Division Multiplexing), QPSK (Quadrature Phase Shift Keying), etc. are applied as the modulation / demodulation method.

  The baseband signal processing unit 50 also designates a mode designating unit for instructing which of the straight mode and the frequency conversion mode the straight / frequency divider circuit 12 and the straight / multiplier circuit 22 are to operate. It has. This mode designation means is configured to be able to set the operation mode manually by the operator or automatically according to the reception frequency of the reception signal, for example.

When the operation mode is manually set by the operator, for example, a communication frequency set in advance as a wireless communication frequency with a desired communication destination for wireless communication, or in the vicinity of a wireless communication relay point. It may be set in accordance with a radio communication frequency band that is predicted to be received at a local point, such as when located.
In the case of automatically setting according to the reception frequency, for example, the reception frequency is detected and the necessity of frequency conversion is determined based on the detection, and the straight / frequency dividing circuit is determined accordingly. 12 and the operation mode of the straight / multiplier circuit 22 may be set.

Further, for example, the mode may be switched at a preset timing so as to detect whether or not a signal in each frequency band is received, and the mode may be determined according to the detection result.
Specifically, when the mode designation means instructs the straight mode or when it is determined that there is no need for frequency conversion based on the received signal, the straight / frequency divider circuit 12 and the straight / multiplier circuit 22 are used. In contrast, a mode signal indicating the straight mode is generated and output.

On the other hand, when the mode designation means instructs to perform frequency conversion or when it is determined that frequency conversion is necessary based on the received signal, the straight / frequency divider circuit 12 and the straight / multiplier circuit 22 On the other hand, a mode signal indicating the frequency conversion mode is generated and output.
Further, the baseband signal processing unit 50 switches the frequency of the local oscillation signal of the voltage controlled oscillator 30 according to the mode signal. Specifically, when the straight mode is set as the mode signal, the received signal in the 2.400 to 2.4835 GHz band received as the 2.4 GHz band signal is preset as the intermediate frequency signal IF. The frequency for the 2.4 GHz band that can be converted into a signal of a predetermined frequency and can convert the intermediate frequency signal IF composed of the transmission data from the baseband signal processing unit 50 to the frequency of the 2.4 GHz band. Set to. On the other hand, when the frequency conversion mode is set as the mode signal, the received signal in the 2.575 to 2.625 GHz band obtained by dividing the received signal in the 5.2 GHz band by 1/2 is used as the intermediate frequency signal IF. 5.2 GHz, which is a frequency that can be converted into a signal having a predetermined frequency set in advance, and that can convert an intermediate frequency signal IF composed of transmission data from the baseband signal processing unit 50 to a frequency in the 5.2 GHz band. Set the frequency for the band.

Next, the operation of the first embodiment will be described.
Now, it is assumed that the wireless communication device 100 is operated in the IEEE 802.11b wireless LAN band (2.4 to 2.4835 GHz) (hereinafter referred to as 2.4 GHz band).
In FIG. 1, the receiving circuit 14 and the transmitting circuit 24 can operate with respect to the band of 2.4000 to 2.625 GHz, and therefore do not need to perform frequency conversion.

  Therefore, for example, when the operator designates the straight mode with the mode designation means, a mode signal instructing the straight mode is output to the straight / frequency divider circuit 12 and the straight / multiplier circuit 22, and for this reason, the straight / frequency divider circuit 12 Does not perform a frequency division operation, and the straight / multiplication circuit 22 does not perform a multiplication operation. The voltage controlled oscillator 30 operates so as to output a local oscillation signal having a frequency for the 2.4 GHz band.

For this reason, the reception signal in the 2.4 GHz band is directly input to the reception circuit 14 via the straight / divider circuit 12, where amplification processing is performed, and a local oscillation signal having a frequency for the 2.4 GHz band is used. After being converted to an intermediate frequency signal IF of a predetermined frequency and subjected to filter processing, it is output to the baseband signal processing unit 50.
The transmission data from the baseband signal processing unit 50 is output to the transmission circuit 24, where the filtering process is performed, and the frequency is converted into a 2.4 GHz band signal by a local oscillation signal having a frequency for the 2.4 GHz band. After the amplification process is performed, the signal is supplied to the straight / multiplier circuit 22 and transmitted through the transmitting antenna 20 as it is.

  On the other hand, when the wireless communication apparatus 100 is operated in the IEEE802.11a wireless LAN band (5.15 to 5.25 GHz) (hereinafter referred to as the 5.2 GHz band), it is necessary to perform frequency conversion. Therefore, for example, when the operator designates the frequency conversion mode using the mode designating means, a mode signal indicating the frequency conversion mode is output to the straight / divider circuit 12 and the straight / multiplier circuit 22, and the straight / divider circuit 12 Then, the frequency dividing operation “1/2” is performed, and the straight / multiplier circuit 22 performs the “2 ×” multiplication operation. The voltage controlled oscillator 30 outputs a local oscillation signal having a frequency for the 5.2 GHz band.

For this reason, the received signal in the 5.2 GHz band (5.15 to 5.25 GHz) is divided by 1/2 in the straight / divider circuit 12 and converted to a band of 2.575 to 2.625 GHz. Thereafter, the signal is supplied to the receiving circuit 14.
Here, since the receiving circuit 14 is formed so as to be able to process a radio frequency band of 2.400 to 2.625 GHz, 2 of 2.575 to 2.625 GHz obtained by dividing the 5.2 GHz band by 1/2. The reception signal in the vicinity of .4 GHz is amplified in the reception circuit 14 in the same manner as the signal in the 2.4 GHz band. In this case, local oscillation of the frequency for the 5.2 GHz band from the voltage controlled oscillator 30 is performed. After the signal is converted into an intermediate frequency signal IF having a predetermined frequency, a filter process is performed, and this is supplied to the baseband signal processing unit 50.

  When transmitting data in the 5.2 GHz band, the intermediate frequency signal IF consisting of the transmission data from the baseband signal processing unit 50 is input to the transmission circuit 24 and subjected to filtering, and then the voltage controlled oscillator The signal is converted into a signal in the vicinity of 2.4 GHz of 2.575 to 2.625 GHz by the local oscillation signal for 5.2 GHz band from 30, and further amplified and supplied to the straight / multiplier circuit 22. .

At this time, since the straight / multiplication circuit 22 is set to the frequency conversion mode, the input signal in the vicinity of 2.4 GHz, that is, 2.575 to 2.625 GHz is multiplied by 2. The signal is converted into a signal of ˜5.25 GHz, that is, a signal of 5.2 GHz band, and then transmitted through the transmission antenna 20.
As described above, by providing the straight / frequency divider circuit 12 and the straight / multiplier circuit 22, the reception circuit 14 and the transmission circuit 24 can perform processing without distinction between the 2.4 GHz band and the 5.2 GHz band. Therefore, since the 2.4 GHz band and the 5.2 GHz band receiving circuit 14 and the transmitting circuit 24 can be realized without being provided separately, the number of devices constituting the wireless communication device 100 is reduced accordingly. be able to. Therefore, it is possible to reduce the size of the apparatus and reduce costs.

At this time, the straight / divider circuit 12 and the straight / multiplier circuit 22 divide the reception signal or multiply the transmission signal, thereby making the 5.2 GHz band 2.4000 as shown in FIG. The signal is converted into a signal in the band of 2.575 to 2.625 GHz in the vicinity of the 2.4 GHz band of ˜2.4835 GHz.
Here, when a low frequency amplifier and a power amplifier are used for frequency bands such as the 2.4 GHz band and the 5.2 GHz band, the band that handles the operating band of the low noise amplifier and the power amplifier. However, it is difficult to set a wide band that can operate over two separate frequency bands.

  However, as described above, since the 5.2 GHz band is converted to a band in the vicinity of the 2.4 GHz band, the band is reduced with respect to the low noise amplifier and the power amplifier applied to the 2.4 GHz band. Just expand it a little. As mentioned above, it will be difficult to realize a low noise amplifier and power amplifier that can operate over a wide band, but as mentioned above, it will be easily realized if the 2.4 GHz band is slightly expanded. can do.

Therefore, it is possible to easily realize the conventional low noise amplifier and power amplifier by slightly expanding the operation band without requiring a wide band low noise amplifier and power amplifier. This can be easily realized without significant changes to the band wireless communication apparatus 100.
Moreover, since it can be realized only by providing the straight / frequency divider circuit 12 and the straight / multiplier circuit 22 with respect to the conventional 2.4 GHz band wireless communication apparatus 100, it can be realized without significant increase in apparatus. can do. In addition, since the low-noise amplifier and power amplifier, which occupy the largest area and cost, can be shared, it is very effective in reducing the size and cost of the apparatus.

Next, a second embodiment will be described.
In the second embodiment, the frequency conversion of the 2.4 GHz band is performed instead of the 5.2 GHz band in the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The radio communication apparatus 100 according to the second embodiment is provided on the output side of the straight / multiplier circuit 13 and the straight / multiplier circuit 13 for receiving a received signal from the receiving antenna 10 as shown in FIG. A receiving circuit 14a, a straight / dividing circuit 23 for outputting a transmission signal to the transmitting antenna 20, a transmitting circuit 24a provided on the input side of the straight / dividing circuit 23, and a local oscillation signal having a predetermined frequency is output. And a baseband signal processing unit 50 for switching the mode of the straight / multiplier circuit 13 and the straight / divider circuit 23 and for controlling the oscillation frequency of the voltage controlled oscillator 30. .

  The straight / multiplier circuit 13 and the straight / divider circuit 23 are configured in the same manner as the straight / multiplier circuit 22 and the straight / divider circuit 12 in the first embodiment. 13 is configured to be able to multiply a 2.4 GHz band signal, for example, by two, and the straight / frequency divider circuit 23 is configured to be able to divide a 4.8 to 5.25 GHz band signal by 1/2. .

The receiving circuit 14a and the transmitting circuit 24a are formed so as to be operable with respect to a signal of 4.8 to 5.25 GHz band, and the low noise amplifier 15a and the power amplifier 29a are 4.8 to 5.25 GHz. It is configured to be able to process a band signal.
Therefore, in the second embodiment, when the wireless communication apparatus 100 is operated in the IEEE802.11a wireless LAN band, that is, the 5.2 GHz band, the receiving circuit 14a and the transmitting circuit 24a are 4.8. Since the operation is possible with respect to ˜5.25 GHz band, for example, the operator instructs the straight mode with the mode designation means. As a result, the straight / multiplier circuit 13 does not perform a multiplication operation, and the straight / frequency division circuit 23 does not perform a frequency division operation. The voltage controlled oscillator 30 operates so as to output a local oscillation signal having a frequency for the 5.2 GHz band.

Therefore, the reception signal in the 5.2 GHz band is directly input to the reception circuit 14a through the straight / multiplication circuit 13, where amplification processing is performed, and a local oscillation signal for the 5.2 GHz band has a predetermined frequency. After being converted to the intermediate frequency signal IF and subjected to filter processing, it is output to the baseband signal processing unit 50.
On the other hand, the intermediate frequency signal IF composed of the transmission data from the baseband signal processing unit 50 is output to the transmission circuit 24a, where the filtering process is performed, and the 5.2 GHz band is generated by the local oscillation signal for the 5.2 GHz band. After frequency conversion into a signal and amplification processing, the signal is supplied to the straight / frequency divider circuit 23 and transmitted through the transmitting antenna 20 as it is.

On the other hand, when operating the wireless communication apparatus 100 in the IEEE802.11b wireless LAN band, that is, the 2.4 GHz band, for example, the operator instructs the frequency conversion mode using the mode specifying means. As a result, the frequency conversion mode is instructed to the straight / multiplier circuit 13 and the straight / divider circuit 23.
Therefore, the straight / multiplier circuit 13 performs a double multiplication operation, and the straight / frequency divider circuit 23 performs a "1/2" frequency division operation. The voltage controlled oscillator 30 outputs a local oscillation signal for 2.4 GHz band.

For this reason, the reception signal in the 2.4 GHz band (2.4 to 2.4835 GHz band) is multiplied by 2 in the straight / multiplier circuit 13, and as shown in FIG. 4, the 5.2 GHz band (5.15 to 5) .25 GHz), which is a frequency in the vicinity of 4.8 to 4.967 GHz, and then supplied to the receiving circuit 14a.
Here, since the reception circuit 14a is formed so as to be able to process a radio frequency band of 4.8 to 5.25 GHz, a reception signal in the vicinity of 5.2 GHz obtained by multiplying the 2.4 GHz band by 2 is 5. After being processed in the same manner as the signal of the 2 GHz band, the amplification process is performed in the receiving circuit 14a, and after being converted into the intermediate frequency signal IF of the predetermined frequency by the local oscillation signal for the 2.4 GHz band from the voltage controlled oscillator 30, Filter processing is performed, and this is supplied to the baseband signal processing unit 50.

  On the other hand, when transmitting data in the 2.4 GHz band, the intermediate frequency signal IF composed of the transmission data from the baseband signal processing unit 50 is input to the transmission circuit 24a, subjected to filter processing, and from the voltage controlled oscillator 30. The 2.4 GHz band local oscillation signal is converted to a signal of 4.8 to 4.967 GHz band in the vicinity of the 5.2 GHz band, and further amplified and supplied to the straight / frequency divider circuit 23. . At this time, since the straight / frequency divider circuit 23 is set to the frequency conversion mode, the input signal of 4.8 to 4.967 GHz is divided by 1/2 to obtain a signal of 2.4 to 2.4835 GHz. That is, after being converted to a 2.4 GHz band signal, the signal is transmitted via the transmission antenna 20.

Accordingly, in this case as well, signals in the 2.4 GHz band and the 5.2 GHz band can be transmitted and received, so that the same operational effects as those of the first embodiment can be obtained.
In the first and second embodiments, signals in two frequency bands, ie, the IEEE802.11a wireless LAN band of the 5.2 GHz band and the IEEE802.11b wireless LAN band of the 2.4 GHz band are transmitted and received. However, the present invention is not limited to this.

  Depending on the combination of frequency bands to be transmitted and received, the frequency band can be arbitrarily set, such as tripled and 1/3 divided, and the frequency band when multiplied by N or divided by 1 / N according to the combination of the frequency bands. The multiplication number and the frequency division number may be set so as to be close to each other, and any combination of frequency bands may be used as long as it is a combination of frequency bands satisfying this. At this time, since the frequency band corresponding to each wireless communication system is adjacent when performing processing in the transmission circuit and the reception circuit, the operable frequency range of the transmission circuit and the reception circuit can be made narrower. In consideration of this, it is desirable to set a combination of radio communication systems, a multiplication number, or a frequency division ratio.

Here, in each of the above embodiments, since the 5.2 GHz band and the 2.4 GHz band are combined, it is possible to realize a wireless communication device that combines an IEEE 802.11a wireless LAN device and an IEEE 802.11b wireless LAN device. Can do.
For example, by combining the 1.5 GHz band and the 800 MHz band and multiplying the frequency by 2 or 1/2, it is possible to realize a mobile phone that combines a 1.5 GHz band mobile phone and an 800 MHz band mobile phone. Also, by combining the 1.9 GHz band and the 800 MHz band and multiplying by 2 or dividing by 1/2, a wireless communication device that combines a 1.9 GHz band personal handyphone system and an 800 MHz band mobile phone is realized. Can do. In addition, for example, by combining the 800 MHz band and the 2.4 GHz band, multiplying by 3 or dividing by 1/3, the mobile phone in the 800 MHz band and the IEEE802.11b wireless LAN device in the 2.4 GHz band are combined. A wireless communication device can be realized.

  In each of the above embodiments, a case has been described in which a signal in a plurality of frequency bands can be processed by dividing or multiplying each of the transmission frequency and the reception frequency. It is not necessary to share the receiving circuit together, and only one of them may be shared. In other words, for example, only the low noise amplifier may be shared, and the power amplifier may be provided for each frequency band of the wireless communication system. Conversely, the low noise amplifier is provided for each frequency band, and the power amplifier is shared. You may do it. In particular, when it is difficult to provide a high power multiplier circuit or frequency divider circuit, only the receiving circuit, that is, the low noise amplifier may be shared.

In each of the above embodiments, the case where the reception antenna 10 and the transmission antenna 20 are individually provided has been described. However, one antenna may be shared and switched according to transmission and reception.
In each of the above embodiments, the frequency in the vicinity of the other frequency band is obtained by frequency-converting one of the frequency bands of the 2.4 GHz band or the 5.2 GHz band. However, the present invention is not limited to this, and both the signals in the two frequency bands are multiplied or divided so that the frequency after the multiplication or division becomes the same frequency band. Alternatively, the frequency may be converted.

  In each of the above embodiments, the case where signals in two frequency bands of 2.4 GHz band or 5.2 GHz band are transmitted and received has been described. However, the present invention is not limited to this, and three or more frequency bands are used. These signals may be transmitted and received. In this case, after frequency conversion by the straight / divider circuit or the straight / multiplier circuit, the frequency of the received signal falls within the operable frequency range of the low noise amplifier 15, and the frequency in the operable frequency range is The frequency division ratio of the straight / frequency divider circuit, the frequency multiplication number of the straight / multiplier circuit, and the frequency of the transmission signal after frequency conversion by the straight / frequency divider circuit or straight / multiplier circuit, The operable frequency range of the power amplifier 29 may be set.

  In the above embodiment, the straight / frequency divider circuit 12 or the straight / multiplier circuit 13 corresponds to the reception frequency variable means, and the straight / multiplier circuit 22 or the straight / frequency divider circuit 23 corresponds to the transmission frequency variable means. Yes.

It is a block diagram which shows an example of the radio | wireless communication apparatus in the 1st Embodiment of this invention. It is explanatory drawing with which it uses for operation | movement description of this invention. It is a block diagram which shows an example of the radio | wireless communication apparatus in the 2nd Embodiment of this invention. It is explanatory drawing with which it uses for operation | movement description of this invention. It is a block diagram which shows an example of the conventional radio | wireless communication apparatus.

Explanation of symbols

  12 straight / divider circuit, 14 receiver circuit, 22 straight / multiplier circuit, 24 transmitter circuit

Claims (4)

In a wireless communication device including a wireless transmission circuit and a wireless reception circuit capable of wireless transmission and reception in a preset operable radio frequency band,
A reception frequency variable means capable of converting a radio reception frequency of a reception signal from a radio antenna into a frequency within the operable radio frequency band, and a transmission frequency of an output signal to the radio antenna output from the radio transmission circuit, Comprising at least one of transmission frequency variable means capable of conversion to a frequency of a desired radio frequency band,
A radio communication apparatus characterized in that when radio transmission / reception is performed in a radio frequency band outside the operable radio frequency band, frequency conversion is performed by the reception frequency variable means and the transmission frequency variable means. The reception frequency variable means and the transmission frequency variable means include a multiplier circuit or a frequency divider circuit,
For each of a plurality of radio frequency bands to be communicated, the representative one of the radio frequency band and the converted frequency band when the frequency is divided or multiplied, and the representative of each radio frequency band to be communicated is a closer band. 2. The wireless communication apparatus according to claim 1, wherein a range including all of the representative radio frequency bands or conversion frequency bands when located at the position is set as the operable radio frequency band.   3. The reception frequency varying means and the transmission frequency varying means operate in one of a frequency conversion mode for performing frequency conversion on an input signal and a non-frequency conversion mode. Wireless communication device. The radio frequency band of the communication target is a radio frequency band of 5.2 GHz band and a radio frequency band of 2.4 GHz band,
The wireless communication device according to any one of claims 1 to 3, wherein the operable frequency band is set to a band of 2.400 to 2.625 GHz or a band of 4.8 to 5.25 GHz. .

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