JP3993573B2 - Wireless communication device compatible with multiple wireless systems - Google Patents

Description

  The present invention relates to a wireless communication apparatus capable of supporting a plurality of wireless systems.

  In addition to mobile phone systems, that is, PDC, CDMAOne (registered trademark), CDMA2000 (registered trademark), and PHS, various wireless systems such as a wireless LAN system and Bluetooth (registered trademark) have been put into practical use in recent years. There are several standards for wireless LAN systems that have already been or are being formulated by the IEEE 802 Committee. As for the frequency band used in each standard (also called system band), for example, IEEE 802.11a is set to 5.15GHz-5.25GHz, 5.25GHz-5.35GHz, 5.725GHz-5.825GHz, etc., and IEEE 802.11b / g is 2.4. GHz-2.497 GHz is set.

  As described above, wireless LAN systems of various standards have advantages and disadvantages such as transmission speed and size of service area, and in the future, it is hoped that users can select and use a wireless LAN system of a desired standard according to the application. It is assumed. For this purpose, a wireless communication device that can support a plurality of wireless LAN systems is required.

In Patent Document 1, a local oscillator (local signal generator) common to a plurality of types of communication systems (wireless systems) is used, and a local signal output from the local signal generator and a local signal obtained by dividing the local signal are used. It describes that frequency conversion is performed on the RF reception signal of each wireless system to obtain an output corresponding to each wireless system.
Japanese Patent Laid-Open No. 11-103325

  According to the technique described in Patent Document 1, although the configuration of the local signal system is simplified, the components after the frequency converter are separate for each radio system, so that the radio communication device has an increased mounting area and an increased price. Is inevitable. In order to reduce the mounting area of the wireless communication device and reduce the cost, the wireless analog circuit may be integrated into an IC (integrated circuit). By making an element such as a resistor, a capacitor, an inductor, and a transistor into an IC, the number of elements mounted on the substrate can be reduced. In order to lower the price of the wireless communication device, it is necessary to lower the price of the IC.

  Since the price of an IC is generally proportional to the chip area of the IC, it is necessary to reduce the number of elements in the IC. However, in the wireless communication apparatus described in Patent Document 1, since the local signal system is only shared by a plurality of wireless systems, the number of elements in the IC is not sufficiently reduced at present, and thus the chip area is not sufficient. Is not very small and can not be expected to reduce prices.

  An object of the present invention is to provide a wireless communication device that is small and inexpensive by reducing the number of elements by further sharing components in a wireless communication device that can support a plurality of wireless systems.

In order to solve the above-described problem, according to one aspect of the present invention, a local signal generator that generates a first local signal, a first RF reception signal corresponding to a first radio system using the first local signal, and At least one frequency converter for converting a second RF received signal corresponding to the second radio system into an intermediate frequency signal of the same frequency, wherein the frequency of the first RF received signal is f _RF1 , and the frequency of the second RF received signal. the when the f _RF, the frequency f _LO11 of the first local signal to provide a wireless communication device capable of supporting a plurality of radio systems to be set to _{f LO11 = (f RF1 + f} RF2) / 2.

According to another aspect of the present invention, a local signal generator for generating a first local signal, a first RF reception signal corresponding to a first radio system using the first local signal, and a second radio system are supported. At least one frequency converter that converts the second RF received signal into an intermediate frequency signal of the same frequency, the frequency of the first RF received signal is f _RF1 , the frequency of the second RF received signal is f _RF , and the first frequency converter. When the larger one of the use frequency bandwidths of the radio system and the second radio system is BW, the frequency f _LO11 of the first local signal is f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2 or _Provided is a radio communication apparatus capable of supporting a plurality of radio systems set so as to satisfy the condition of f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2.

According to another aspect of the present invention, a local signal generator that generates a first local signal, a frequency divider that divides the first local signal to generate a second local signal, a first baseband signal, Quadrature modulation that generates an intermediate frequency signal of a specific frequency by performing quadrature modulation on the second baseband signal using the second local signal and the third local signal having a phase difference of 90 ° with the second local signal. And at least one frequency converter for converting the intermediate frequency signal into a first RF transmission signal corresponding to the first radio system and a second RF transmission signal corresponding to the second radio system using the first local signal. The frequency of the first RF transmission signal is f _RF1 , the frequency of the second RF transmission signal is f _RF2 , and the respective frequencies used by the first radio system and the second radio system The frequency f _LO11 of the first local signal is f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2 or f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW, where BW is the larger bandwidth. Provided is a wireless communication apparatus capable of supporting a plurality of wireless systems set to satisfy the condition of / 2.

  According to the present invention, in the heterodyne receiver or transmitter corresponding to a plurality of wireless systems, the RF reception signal corresponding to each wireless system is converted to an intermediate frequency signal, or the intermediate frequency signal is transmitted to each wireless system. By sharing the local signal used for frequency conversion to the corresponding RF transmission signal and making the frequency of the intermediate frequency signal common to each wireless system, the circuit of the intermediate frequency stage can be shared by each wireless system. As a result, when the wireless communication apparatus is integrated into an IC, the IC chip area and the mounting area on the substrate can be reduced, and therefore it is possible to reduce the size and the price.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
(Composite receiver)
FIG. 1 shows a composite receiver in a wireless communication apparatus that can support the first and second wireless systems having different system bands according to the first embodiment of the present invention. The RF frequencies used for transmission and reception in the first and second radio systems are assumed to be f _RF1 and f _RF2 (f _RF1 > f _RF2 ), respectively.

RF reception signals of frequencies f _RF1 and f _RF2 output from an antenna (not shown) are input to band pass filters (BPF) 101 and 102 that pass a desired wave (signal component) and attenuate frequency components other than the desired wave. The The output signals of the bandpass filters 101 and 102 are input to down converters (D / C) 105 and 106, which are frequency converters, via low noise amplifiers (LNA) 103 and 104, respectively, and multiplied by the first local signal LO11. By doing so, it is converted into an intermediate frequency signal having the same frequency, that is, a common intermediate frequency f _IF . Hereinafter, the intermediate frequency is referred to as an IF frequency, and the intermediate frequency signal is referred to as an IF signal.

The first local signal LO11 output from the first local signal generator 107 is input to the down converters 105 and 106 in common. Here, one first local signal generator 107 is used by selecting f _LO11 = (f _RF1 + f _RF2 ) / 2 as the frequency f _LO11 (hereinafter referred to as the first local frequency) of the first local signal LO11. Thus, the RF reception signals of the frequencies f _RF1 and f _RF2 corresponding to the first and second radio systems can be converted into an IF signal having a common IF frequency f _IF .

The IF signals from the down converters 105 and 106 are input to a quadrature demodulator (QDEMOD) through a bandpass filter 108 for removing unnecessary waves. The quadrature demodulator has two mixers 109 and 110, and an IF signal is input to one input terminal of each of the mixers 109 and 110. The other input terminal of each of the mixers 109 and 110 receives a quadrature local signal generated by the 90 ° phase shifter 112 from the local signal LO12 output from the second local signal generator 111, that is, a phase difference of 90 °. Two second local signals having a frequency f _LO12 (hereinafter _{referred to} as a second local frequency) are input. When a frequency divider is used as the 90 ° phase shifter 112, the frequency 2f _IF twice the IF frequency is set to the second local frequency _fLO12 .

The IF signal from the band pass filter 109 is converted into a baseband frequency by the mixers 109 and 110, and baseband signals orthogonal to each other, that is, an _ICH signal and a _QCH signal are generated. The I _CH signal and the Q _CH signal are input to a baseband processing circuit (not shown), where the original data is decoded by known digital signal processing.

  According to the present embodiment, when the frequency of an RF reception signal in two radio systems is converted to an IF signal, one first local signal generator 107 is commonly used, so the number of constituent elements of the local signal system is reduced. be able to. The first local signal generator 107 is usually realized by a PLL (Phase-Locked Loop) including a VCO (Voltage Controlled Oscillator). The PLL is composed of a loop filter mounted outside the IC and a circuit group mounted inside the other IC. Therefore, the effect of reducing the circuit scale of the local signal system by sharing the first local signal generator 107 between the two wireless systems is great.

  Furthermore, in this embodiment, the RF reception signal in each wireless system is converted into an IF signal of the same frequency by the frequency converters 105 and 106. Therefore, the IF stage processing system, for example, the bandpass filter 108, the mixers 109 and 110 of the quadrature demodulator QDEMOD, the local signal generator 111, and the 90 ° phase shifter 112 can be shared by the two wireless systems. Accordingly, the circuit scale of the local signal system for frequency conversion from RF to IF can be reduced, and the circuit scale of the entire receiving unit can be greatly reduced, and the mounting area in the IC can be reduced and the number of elements can be reduced. An inexpensive wireless communication device can be realized.

Next, a specific frequency setting example of each part in FIG. 1 will be described with reference to FIGS. 2 and 3. 2 and 3, it is assumed that the frequencies of the RF reception signals of the first radio system and the second radio system are f _RF1 = 5.2 GHz and f _RF2 = 2.4 GHz, respectively. In this case, the first local frequency is f _LO11 = 3.8 GHz, and the IF frequency is f _IF = 1.4 GHz. Further, it is assumed that the first wireless system and the second wireless system adopt a TDD (Time Division Duplex) method.

When the first radio system of the 5.2 GHz band is operating, the RF reception signal of f _RF1 = 5.2 GHz is converted into an IF signal of f _IF = 1.4 GHz. According to TDD, when the first radio system is operating, the 2.4 GHz band second radio system is stopped, so the 2.4 GHz band RF received signal is not converted to a 1.4 GHz IF signal. . Similarly, when the second second radio system in the 2.4 GHz band is operating, the first radio system in the 5.2 GHz band is stopped, so that only the 2.4 GHz band RF received signal is the IF signal in the 1.4 GHz band. The 5.2 GHz band RF received signal is not converted into a 1.4 GHz band IF signal.

  Next, when the circuits after the low noise amplifiers 103 and 104 are realized by one IC, the first radio system and the second radio system are caused by leakage of the RF reception signal due to the coupling between the input terminals of the low noise amplifiers 103 and 104. The problem that each of the received RF signals is mixed as an unnecessary wave in each system will be described with reference to FIGS.

  When only the first radio system is operating, the 2.4 GHz band RF received signal of the second radio system is passed through the bandpass filter 102, the substrate and the IC to the input terminal of the low noise amplifier 103 of the first radio system. Consider a leak. In this case, the 5.2 GHz RF reception signal and the leaked 2.4 GHz band RF reception signal are input to the input terminal of the low noise amplifier 103 of the first wireless system, and input to the down converter 105 via the low noise amplifier 103. The Therefore, as a result of the 2.4 GHz band RF reception signal being converted to the same IF frequency (1.4 GHz) as the 5.2 GHz band RF reception signal by the down converter 105, it is mixed as an unnecessary wave in the first wireless system. In FIG. 5, unnecessary wave components mixed from the second wireless system are indicated by hatching.

  The reason why such unwanted waves are mixed is that the frequency of the RF reception signal of the first wireless system and the second wireless system is in the relationship of the image frequency with respect to the first local frequency. Similarly, when only the second radio system is operating, the RF reception signal of the first radio system leaks to the input terminal of the low noise amplifier 104 of the second radio system and is mixed as an unnecessary wave in the second radio system. Will do.

The mixing of unnecessary waves as described above can be avoided by using a method of changing the first local frequency _fLO11 depending on which of the first radio system and the second radio system operates. Hereinafter, this method will be described with reference to FIGS.

First, the case where only the first radio system operates and the RF reception signal of the second radio system is mixed in the input terminal of the low noise amplifier 103 of the first radio system will be described with reference to FIGS. 6 and 7. The used frequency bandwidths (also referred to as system bandwidths) of the first wireless system and the second wireless system are BW1 and BW2, respectively, and the larger of BW1 and BW2 is BW. Also, let BW1 and BW2 be the passband widths of the bandpass filters 101 and 102 of the first and second wireless systems, respectively. In this case, in order to prevent the RF reception signals of the first and second wireless systems from being related to the image frequency,
f _LO11 <fav-BW / 2 (1)
f _LO11 > fav + BW / 2 (2)
Each frequency may be set so as to satisfy one of the following relationships. Here, fav is an average frequency of RF reception signals of the first radio system and the second radio system, that is, fav = (f _RF1 + f _RF2 ) / 2.

Here, it is assumed that f _RF1 = 5.2 GHz, f _RF2 = 2.4 GHz, and BW = 100 MHz, and the first local frequency f _LO11 is set to 3.9 GHz satisfying Expression (2). In this case, the IF frequency is f _IF = 1.3 GHz, and the image frequency for the first wireless system is 2.6 GHz. Since the image frequency component for the first radio system is greatly attenuated by the bandpass filter 102 of the second radio system, the image frequency component is hardly mixed into the input terminal of the low noise amplifier 103 of the first radio system. From another viewpoint, when the 2.4 GHz RF received signal passes through the bandpass filter 102 of the second radio system and enters the down converter 105 of the first radio system, the down converter 105 causes the 1.5 GHz IF signal to be mixed. Is converted to That is, the 1.5 GHz band IF signal, which is an unnecessary wave, has a frequency different from that of the 1.3 GHz band IF signal, which is a desired wave, and can be easily suppressed by using an appropriate filter.

Next, the case where only the second radio system operates and the RF reception signal of the first radio system is mixed into the input terminal of the low noise amplifier 104 of the second radio system will be described with reference to FIGS. 8 and 9. In this case, the first local frequency f _LO11 is set to 3.7 GHz that satisfies Expression (1). Since the frequency of the RF reception signal of the second radio system is 2.4 GHz, the IF frequency is 1.3 GHz as in the operation of the first radio system. When a 5.2 GHz band signal, which is an unwanted wave, leaks from the first wireless system to the second wireless system, f _LO11 = 3.7 GHz, so the 5.2 GHz band signal is converted into a 1.5 GHz band IF signal by the down converter 106. Is done. Also in this case, since the frequency of the 1.5 GHz band IF signal, which is an unnecessary wave, is different from that of the 1.3 GHz band IF signal, which is a desired wave, it is easily suppressed by using an appropriate filter.

  As described above, by setting the first local frequency so that the RF reception signals of the first and second radio systems are not related to the image frequency, other radio waves that are unnecessary waves for each radio system are set. When the RF reception signal of the system is mixed, the unnecessary wave is converted into an IF signal having a frequency different from that of the desired wave, so that the reception characteristic of the desired wave is not adversely affected.

In the above description, when the first wireless system is operated in FIGS. 6 and 7, the first local frequency f _LO11 is set according to the equation (2). However, the same effect can be obtained even if it is set according to the equation (1). Can do. For example, when f _LO11 = 3.7 GHz is set, when only the first radio system operates, the 5.2 GHz RF reception signal of the first radio system, which is a desired wave, is converted into a 1.5 GHz IF signal. On the other hand, since the 2.4 GHz RF reception signal mixed from the second radio system which is an unnecessary wave is converted into a 1.3 GHz IF signal, the frequency does not overlap with the RF reception signal of the first radio system which is a desired wave. It is easily suppressed by the filter.

When only the second radio system operates, by setting f _LO11 to 3.9 _GHz so that f _LO11 > fav + BW / 2, the RF reception signal of the second radio system, which is the desired wave, is 1.5 GHz IF Converted to a signal. On the other hand, the 5.2 GHz signal mixed from the first radio system, which is an unnecessary wave, is converted into an IF signal having a frequency of 1.3 GHz different from the desired wave, and is similarly suppressed by the filter.

(Composite sending part)
FIG. 10 shows a composite transmission unit in a wireless communication apparatus capable of supporting the first and second wireless systems having different system bands according to the first embodiment of the present invention. The RF frequencies used for transmission / reception in the first and second radio systems are f _RF1 and f _RF2 (f _RF1 > f _RF2 ), respectively. The composite transmission unit shown in FIG. 10 is paired with the composite reception unit shown in FIG.

In FIG. 10, an in-phase baseband signal I _CH (hereinafter referred to as I _CH signal) and a quadrature baseband signal Q _CH (hereinafter referred to as Q _CH signal) from a baseband processing circuit (not shown) are supplied to a quadrature modulator (QMOD). Entered. The quadrature modulator has two mixers 201 and 202, and an I _CH signal and a Q _CH signal are input to one input terminal of each of the mixers 201 and 202, respectively.

The other input terminal of each of the mixers 201 and 202 has a quadrature local signal generated by the 90 ° phase shifter 204 from the local signal LO ₁₂ output from the second local signal generator 203, that is, a phase difference of 90 °. The two second local signals having the frequency f _LO12 having the following _values are respectively input. Here, the case of using the frequency divider as a 90 ° phase shifter 204, sets a frequency twice the intermediate frequency f _IF to f _LO12.

After the signals output from the mixers 201 and 202 of the quadrature modulator are combined into one IF signal, the IF signal is passed through a band-pass filter 205 for removing unnecessary waves, and the up converter (U / C) is input to 206 and 207. In the up-converters 206 and 207, the IF signal is multiplied by the first local signal LO11 input in common from the first local signal generator 208 to be converted into RF transmission signals of frequencies f _RF1 and f _RF2 . These RF transmission signals of frequencies f _RF1 and f _RF2 are amplified by power amplifiers (PA) 209 and 210, respectively, and further supplied to antennas (not shown) via bandpass filters 211 and 212 for removing unnecessary waves, respectively. Are transmitted as radio waves.

Here, the setting of the frequency (hereinafter referred to as the first local frequency) f _LO11 of the first local signal LO11 is the same as that of the composite reception unit described above, and preferably one of the expressions (1) and (2) It is set to satisfy the relationship. In this case, fav in the equations (1) and (2) is an average frequency of the RF transmission signals of the first radio system and the second radio system.

Thus, after converting the I _CH signal and the Q _CH signal into one IF signal, the frequencies f _RF1 and f _{RF2 of} the first radio system and the second radio system are used by using the first local signal from the local signal generator 208. By generating the RF transmission signal, the area of the IC and the mounting area on the substrate can be reduced similarly to the composite receiver shown in FIG. 1, so that the wireless communication apparatus can be reduced in size and price. .

More specifically, for example, when only the first wireless system is operated, the local frequency is set, for example, to f _LO11 = 3.9 _GHz so that f _LO11 > fav + BW / 2. In this case, since the IF frequency is 1.3 GHz, an image frequency component having a frequency of 2.5 6 GHz is generated in the first wireless system. This image frequency component leaks to the output terminal of the power amplifier 210 of the second radio system, but the leak component is suppressed by the bandpass filter 212 of the second radio system, and is hardly radiated from the antenna of the second radio system.

On the other hand, when operating only the second wireless system, for example, f _LO11 = 3.7 GHz is set so that f _LO11 <fav−BW / 2. In this case, an image frequency component of 5.0 GHz is generated in the second wireless system. Even if this image frequency component leaks to the output terminal of the power amplifier 209 of the first wireless system, the bandpass filter 211 of the first wireless system. Therefore, the leakage component is suppressed and is hardly radiated from the antenna of the first wireless system.

Even if only the first radio system is operated and the first local frequency is set to f _LO11 = 3.7 GHz so that f _LO11 <fav−BW / 2, the same effect can be obtained. In this case, the IF frequency is set to 1.5 GHz. The 2.2 GHz image frequency component generated in the first wireless system leaks to the output terminal of the power amplifier 210 of the second wireless system, but the leakage component is suppressed by the bandpass filter 212 of the second wireless system. Little is radiated from the antenna of the wireless system.

On the other hand, in the case of only the operating second wireless system, by setting f _LO11 <fav + BW / 2 to become so f _LO11 = 3.9GHz, image frequency generated from the second wireless system is a 5.4 GHz. Even if this image frequency component leaks to the output terminal of the power amplifier 209 of the first radio system, the leak component is suppressed by the bandpass filter 211 of the first radio system, so that almost no radiation is radiated from the antenna of the first radio system. Not.

(About the first local signal generator)
In the above-described composite reception unit and composite transmission unit, the first local frequency f _LO1 needs to be able to be changed at least at fav−BW / 2 or less or fav + BW / 2 or more. With recent local signal generation technology, it has become possible to widen the frequency variable range of local signals. For example, the frequency variable range can be widened by switching the resonance frequency of the resonator used in the voltage controlled oscillator (VCO) of the PLL. Two VCOs having different oscillation frequencies may be prepared, and the VCO to be controlled may be switched by a PLL. On the other hand, the frequency variable range of the local frequency can be widened by signal operation without using a local signal source having a particularly wide frequency variable range. Hereinafter, this technique will be described.

FIG. 11 shows a configuration example of a first local signal generator that shifts the first local frequency by multiplying the original local signal of the reference frequency f _LO10 by the frequency- _divided local signal _{obtained by dividing} the frequency by N. That is, in the local signal generator shown in FIG. 11, the original local signal having the frequency f _LO10 generated from the local signal source 301 is _divided by N by the N divider 302 (N is an arbitrary integer), and the frequency f _LO10 / N frequency- _divided local signals are generated, the multiplier 303 multiplies the original local signal and the frequency- _divided local signal, and the frequency f _LO10 (1-1 / N) or f _LO10 ( 1 + 1 / N) is generated as the first local signal.

_{Assuming that} the original local signal of frequency f _LO10 is cosωLOt, the divided local signal after N division is cos (ωLO / N) t, and therefore the output signal of the multiplier 203 is expressed by the following equation.

cosωLOt × cos (ωLO / N) t = 1/2 × {cosωLO (1-1 / N) t + cosωLO (1 + 1 / N) t} (3)
For example, if f _LO10 = 3.8 GHz and N = 16, 3.5625 GHz and 4.0375 GHz are generated. The output signal of the multiplier 203 shown in Expression (3) is input to the bandpass filters 304 and 305, and unnecessary frequency components are suppressed, so that the frequencies f _LO10 (1-1 / N) and f shown in FIG. _LO10 (1 + 1 / N) components are extracted. A matching circuit may be used instead of the bandpass filters 304 and 305.

  One of the output signals of the bandpass filters 304 and 305 is selected by the selector 306 as the first local signal, and the frequency converter (down converter) 105, 106 of the composite reception unit or the frequency converter (up converter) of the composite transmission unit ) 206, 207. With such a configuration, even if the frequency variable range of the reference local signal source 301 is small, the first local frequency is set so that the respective RF frequencies do not become image frequencies between the first wireless system and the second wireless system. can do.

FIG. 13 shows another configuration example of the first local signal generator that shifts the first local frequency by multiplying the original local signal of the reference frequency f _{LO10 by} the _divided local signal _{obtained by dividing} the original local signal by N. Show. In FIG. 11, a band-pass filter is used as a method of removing unnecessary frequency components from the signal generated by multiplication, but FIG. 13 shows a method of removing unnecessary frequency components by signal processing. That is, in the local signal generator shown in FIG. 13, the original local signal of frequency f _LO10 generated from the local signal source 301 is phase- _shifted by 90 ° by shifting the original local signal by the 90 ° phase shifter 307. A first phase shift local signal f _LO100 and a second phase shift local signal f _LO101 having a phase difference are generated.

On the other hand, the original local signal is _divided by N by N divider 302 (N is an arbitrary integer) to generate a _divided local signal of frequency f _LO10 / N, and this _divided local signal is converted into 90 ° phase shifter 308. To generate the third phase-shifting local signal f _LO10N0 and the fourth phase-shifting local signal f _LO10N1 having a phase difference of 90 ° from each other.

Further, the first multiplier 309 multiplies the first phase shift local signal f _LO100 and the third phase shift local signal f _LO10N0, and the second multiplier 310 multiplies the second phase shift local signal f _LO101 and the fourth phase shift. Multiply by the local signal f _LO10N1 . An adder / subtractor 311 adds or subtracts the output signal of the first multiplier 309 and the output signal of the second multiplier 310 to _obtain a signal component having a frequency f _LO10 (1-1 / N) or f _LO10 (1 + 1 / N). As a first local signal.

Here, the signal f _LO100 and CosomegaLOt, the signal f _LO101 and SinomegaLOt, the signal f _LO10N0 and cos (ωLO / N) t, and the signal _{f LO10N1 sin (ωLO / N)} t. By multiplying and adding / subtracting them, one desired frequency component shown in FIG. 14 can be generated as shown in the following trigonometric function formula.

CosωLOt × cos (ωLO / N) t + sinωLOt × sin (ωLO / N) t = cosωLO (1-1 / N) t (4)
CosωLOt × cos (ωLO / N) t-sinωLOt × sin (ωLO / N) t = cosωLO (1 + 1 / N) t (5)
One of the two output signals of the adder / subtractor 311 shown in the equations (4) and (5) is selected by the selector 312 as the first local signal, and the frequency converters (down converters) 105 and 106 of the composite reception unit, or the composite transmission Frequency converters (upconverters) 206 and 207.

With such a configuration, even if the frequency variable range of the reference local signal source 301 is small, the first local frequency is set so that the respective RF frequencies do not become image frequencies between the first wireless system and the second wireless system. can do. Further, only a desired frequency component can be extracted without using a bandpass filter or a matching circuit as in the example of FIG. In the configuration of FIG. 13, when the signals f _LO100 and f _LO101 are generated from the signal f _LO10 by the 90 ° phase shifter 307, the 90 ° phase shift can be performed without changing the frequency. It is preferable to use a CR bridge circuit composed of a resistor and a capacitor, or an analog type 90 ° phase shifter such as a polyphase filter in which they are combined. On the other hand, an analog 90 ° phase shifter may be used as the 90 ° phase shifter 308 for shifting the signal after 1 / N frequency division, or N / 2 if the frequency division ratio N is an even number. A digital 90 ° phase shifter using a frequency divider that divides frequency by 2 after frequency division may be used.

[Second Embodiment]
(Composite receiver)
FIG. 15 shows another configuration example of the composite receiver in the second embodiment of the present invention. The local signal generator 111 for the quadrature demodulator is removed from the composite receiver shown in FIG. A local signal for the quadrature demodulator is generated by adding the frequency divider 113 and dividing the local signal output from the local signal generator 107 by L (L is an arbitrary integer). As described above, the local signal generator for the quadrature demodulator can be reduced only by adding the L divider 113, so that the IC area and the mounting area can be further reduced.

Next, in the configuration of FIG. 15, while satisfying the condition of f _LO11 <fav−BW / 2 or f _LO11 > fav + BW / 2 shown in the expressions (1) and (2), L satisfying f _LO12 = f _LO11 / L is set. An example of setting is shown. For example, a signal in the 5.2 GHz band, that is, an RF reception signal having the frequency f _RF1 is converted into an IF signal having the frequency f _IF by the first local signal _having the frequency f _LO11 . The IF frequency f _IF is equal to the frequency f _LO11 / L. Therefore,
5.2G−f _LO11 = f _LO11 / L (6)
It becomes. When L = 3, f _LO11 = 3.9 GHz, which satisfies the condition of f _LO11 > fav + BW / 2 shown in Equation (2). Here, it is assumed that BW = 100 MHz. On the other hand, the 2.4 GHz band signal, that is, the RF reception signal having the frequency f _RF2 is converted into an IF signal having the frequency f _IF = f _LO11 / L by the first local signal _having the frequency f _LO11 . Therefore,
f _LO11 -2.4G = f _LO11 / L (7)
It becomes. When L = 3, f _LO11 = 3.6 GHz, which satisfies the condition of f _LO1 <fav + BW / 2 shown in Equation (1). Accordingly, it is possible to _divide the RF reception signal having the frequency f _LO11 to generate the first local signal for frequency conversion to the IF signal and to avoid the image frequency.

(Composite sending part)
FIG. 16 shows another configuration example of the composite transmission unit according to the second embodiment of the present invention. The local signal generator 203 for the quadrature modulator is removed from the composite reception unit shown in FIG. A local signal for the quadrature modulator is generated by adding a frequency divider 213 and dividing the local signal output from the local signal generator 208 by L. As described above, since the local signal generator for the quadrature modulator can be reduced only by adding the L divider 213, the area and mounting area of the IC can be further reduced. Since the frequency setting is the same as described above, a detailed description is omitted here.

[Third Embodiment]
In the case where a wireless system in which the frequency of the first local signal input to the down converters 105 and 106 is higher than the frequency of the RF reception signal and a wireless system in which the frequency of the first local signal is lower than the frequency of the RF reception signal coexist. The relationship between the output baseband signals (referred to as the first baseband signal and the second baseband signal) I _CH signal and Q _CH signal is different. Hereinafter, this reason will be described by taking the composite reception unit as an example, but the same applies to the composite transmission unit.

In order to simplify the explanation, it is assumed that the RF received signal is cos (ω _RF t + θ) and the local signal is cos (ω _LO t). The IF signal is a low frequency component of a signal obtained by multiplying the RF reception signal and the local signal by the down converter 105 or 106, and becomes cos {(ω _RF −ω _LO ) t + θ}. When ω _RF −ω _LO = ω _IF > 0, the IF signal is cos (ω _IF t + θ), and when ω _LO −ω _RF = ω _IF > 0, the IF signal is cos (ω _IF t−θ). . Here, ω _RF is the angular frequency of the RF reception signal, ω _LO is the angular frequency of the local signal, and ω _IF is the angular frequency of the IF signal.

When the IF signal is converted into a baseband signal by the quadrature demodulator, the I _CH signal is extracted from the first baseband signal obtained by multiplying the IF signal and the local signal cos (ω _IF t) by the mixer 109, and Q _CH The signal is extracted from the second baseband signal obtained by multiplying the IF signal and the local signal sin (ω _IF t) by the mixer 110. When ω _RF −ω _LO = ω _IF > 0, the first baseband signal output from the mixer 109 is 1/2 cos θ , and the second baseband signal output from the mixer 110 is −1/2 sinθ. . On the other hand, when ω _LO −ω _RF = ω _IF > 0, the first baseband signal is 1/2 cosθ and the second baseband signal is 1/2 sinθ.

That is, when a wireless system in which the frequency of the first local signal input to the down converters 105 and 106 is higher than the frequency of the received RF signal and a wireless system in which the frequency of the first local signal is lower than the RF frequency are mixed, Q The polarity of the second baseband signal used as the _CH signal differs depending on the radio system.

Therefore, in the present embodiment, as shown in FIG. 17, the baseband signal output circuit 115 provided in addition to the composite receiver of FIG. 1 performs the following on the first baseband signal and the second baseband signal. By performing such processing, a wireless system in which the frequency of the first local signal input to the down converters 105 and 106 is higher than the frequency of the received RF signal and a wireless system in which the frequency of the first local signal is lower than the RF frequency are mixed. Even in this case, the I _CH signal and the Q _CH signal are always output correctly.

The baseband signal output circuit 115 outputs a first baseband signal from the mixer 109 as an I _CH signal, a first mode for outputting a second baseband signal from the mixer 110 as a Q _CH signal, and a first baseband One of the second modes in which the signal is output as the Q _CH signal, the polarity of the second baseband signal is inverted, and the signal is output as the I _CH signal can be selected. Whether the first mode or the second mode is selected is controlled by a control signal 116 that is set depending on the wireless system used for communication.

That is, the first baseband signal is 1/2 cosθ in the case of ω _RF −ω _LO = ω _IF > 0 and ω _LO −ω _RF = ω _IF > 0, whereas the second baseband signal is When ω _RF −ω _LO = ω _IF > 0, the signal is inverted to −1/2 sin θ, and when ω _LO −ω _RF = ω _IF > 0, the polarity is inverted to 1/2 sin θ. Therefore, in the baseband signal output circuit 118, for example, the first mode is selected when ω _RF −ω _LO = ω _IF > 0, and the second mode is selected when ω _LO −ω _RF = ω _IF > 0.

  FIG. 18 shows an example of the baseband signal output circuit 115. Here, it is assumed that the input (RF reception signal and local signal) and output of the mixer 109 are differential signals. In this case, the polarity can be inverted by using a 2-input / 2-output switch circuit for the baseband signal output circuit 115 and exchanging the differential output signal pair from the mixer 110 as the second baseband signal. It is also possible to invert the polarity after the second baseband signal is converted into a digital signal by the A / D converter.

[Fourth Embodiment]
FIG. 19 shows an example in which a baseband signal output circuit 117 is added to the composite receiver shown in FIG. The baseband signal output circuit 117 outputs a first baseband signal as an I _CH signal, a first mode for outputting a second baseband signal as a Q _CH signal, and a first baseband signal as a Q _CH signal. Then, any one of the second modes in which the second baseband signal is output as the _ICH signal (in other words, the first baseband signal and the second baseband signal are switched) can be selected. Also in the baseband signal output circuit 117, which one of the first mode and the second mode is selected is controlled by a control signal 118 that is set depending on the wireless system used for communication.

As described above, when ω _RF −ω _LO = ω _IF > 0, the first baseband signal is 1/2 cos θ, the second baseband signal is −1/2 sin θ, and ω _LO −ω _RF = ω _IF When> 0, the first baseband signal is 1/2 cosθ and the second baseband signal is 1/2 sinθ. In the latter case, when the first baseband signal and the second baseband signal are interchanged, the first baseband signal becomes 1/2 sinθ and the second baseband signal becomes 1/2 cosθ. If these signals are shifted by 90 ° to be an I _CH signal and a Q _CH signal, I _CH = 1/2 sin (θ + π / 2) = 1/2 cos θ, Q _CH = 1/2 cos (θ + π / 2) = −1 / 2sinθ. This result is the same as the first baseband signal and the second baseband signal when ω _RF −ω _LO = ω _IF > 0. If the 90 ° phase shift is not performed, the reference is shifted by 90 °. However, since the reference phase is not a problem in communication, even if the first baseband signal and the second baseband signal are interchanged, I _CH Signal and _QCH signal can be output.

In this way, by replacing the first baseband signal output from the mixer 109 and the second baseband signal output from the mixer 110 by the baseband signal output circuit 117, ω _RF −ω _LO = ω _IF > 0. As in the case, the I _CH signal and the Q _CH signal can be obtained correctly.

  FIG. 20 shows an example of the baseband signal output circuit 117. The baseband signal output circuit 117 is a four-input / four-output switch circuit, and can exchange the first baseband signal from the mixer 109 and the second baseband signal from the mixer 110. Here, it is assumed that the inputs (RF reception signal and local signal) and output of the mixers 109 and 110 are differential signals. Note that the first baseband signal and the second baseband signal may be switched after being converted into digital signals by the A / D converter, respectively.

[Fifth Embodiment]
Similarly to the above-described composite reception unit, in the composite transmission unit, the radio system in which the frequency of the first local signal input to the up-converters 206 and 207 is higher than the frequency of the RF transmission signal, and the frequency of the first local signal In some cases, wireless systems having a frequency lower than the frequency of the RF transmission signal coexist. In such a case, the polarity of the second baseband signal obtained from the Q _CH signal is made different depending on the radio system, or the first baseband signal and the second baseband signal obtained from the I _CH signal and the Q _CH signal. Need to be replaced.

In FIG. 21, a baseband signal input circuit 215 for performing such processing is added to the composite transmitter shown in FIG. The baseband signal input circuit 215 outputs the I _CH signal as the first baseband signal, a first mode for outputting a Q _CH signal as the second baseband signal, and outputs the I _CH signal as the first baseband signal The _QCH signal can be selected from any one of the second modes in which the polarity of the first baseband signal is inverted and output as the second baseband signal. Which one of the first mode and the second mode is selected is controlled by a control signal 216 set depending on the wireless system used for communication.

FIG. 22 shows an example of the baseband signal input circuit 215. Here, it is assumed that the input (IF signal and local signal) and output of the mixer 202 are differential signals. In this case, using a switching circuit having two inputs, 2 outputs the baseband signal input circuit 215, by interchanging the differential signal pair of Q _CH signal can reverse the polarity of the Q _CH signal. Note that the polarity of the Q _CH signal can be inverted before the I _CH signal and the Q _CH signal are converted into analog signals by the D / A converter.

[Sixth Embodiment]
FIG. 23 shows an example in which a baseband signal input circuit 217 is added to the composite transmission unit shown in FIG. The baseband signal input circuit 217 outputs the I _CH signal as the first baseband signal, a first mode for outputting a Q _CH signal as the second baseband signal, and outputs the I _CH signal as the second baseband signal The Q _CH signal is output as the first baseband signal (in other words, the second mode in which the I _CH signal and the Q _CH signal are switched) can be selected. Whether the first mode or the second mode is selected is controlled by a control signal 218 that is set depending on the wireless system used for communication.

FIG. 24 shows an example of the baseband signal input circuit 217. The baseband signal output circuit 217 is a four-input / four-output switch circuit, and can exchange the I _CH signal and the Q _CH signal. Note that the I _CH signal and the Q _CH signal may be switched before being converted into digital signals by the A / D converter.

In short, the relationship between the radio frequency corresponding to each radio system, the frequency of the local signal, the intermediate frequency, the I _CH signal, and the Q _CH signal is exactly the same in the composite receiver and the composite transmitter. Therefore, by providing a baseband signal input circuit that performs processing reverse to the baseband signal output circuit in the composite transmission unit, a correct RF transmission signal is always generated regardless of the wireless system.

  FIG. 25 shows an example in which a part of the composite receiver is modified. The IF signal output from the band pass filter 108 is adjusted in amplitude by a variable gain amplifier (VGA) 120 and then input to the mixers 109 and 110 of the quadrature demodulator. The first baseband signal and the second baseband signal output from the mixers 109 and 110 are input to analog-digital converters (A / D) 123 and 124 via low-pass filters (LPF) 121 and 122, respectively. Converted into a digital signal. The first and second baseband signals of the digital signal are input to the baseband signal output circuit 125.

The digital signal output circuit 125 has the same function as the baseband signal output circuit described above, and is realized by converting the baseband signal output circuit described above into a digital circuit. Processing such as switching between the I _CH signal and the Q _CH signal is controlled by a control signal 126. The I _CH signal and Q _CH output from the digital signal output circuit 125 are input to a baseband processing circuit (not shown), and the original data is decoded.

  Further, as a modification of the composite reception unit, a plurality of frequency converters (down converters) respectively corresponding to a plurality of wireless systems may be provided, and one frequency converter may be shared by a plurality of wireless systems.

FIG. 26 shows an example in which a part of the composite transmission unit is modified. An I _CH signal and a Q _CH signal output from a baseband processing circuit (not shown) are input to a baseband signal input circuit 220, and a digital first baseband signal and a second baseband signal are generated. Processing such as switching between the I _CH signal and the Q _CH signal is controlled by a control signal 221.

  The digital first baseband signal and second baseband signal are converted into analog signals by D / A converters 222 and 223, respectively, and then passed through low-pass filters 224 and 225 to quadrature modulator mixers 201 and 202, respectively. Entered. The output signals from the mixers 201 and 202 are combined into one IF signal, the amplitude is adjusted by the variable gain amplifier 226, and then input to the band pass filter 207.

  Further, as a modification of the composite transmission unit, one frequency converter may be shared by a plurality of radio systems without individually providing a plurality of frequency converters (upconverters) respectively corresponding to the plurality of radio systems.

The block diagram which shows the structure of the composite receiver in the radio | wireless communication apparatus which concerns on one Embodiment of this invention. The figure which shows the example of a frequency setting of each part in the composite receiver shown in FIG. The figure which shows a mode that the RF received signal of two radio | wireless communications systems is converted into the IF signal of the same frequency in the frequency setting example shown in FIG. The figure which shows the mode of RF receiving signal leakage between the radio | wireless systems in the composite receiver shown in FIG. The figure which shows the specific example of the frequency of each part for demonstrating the relationship between RF received signal leakage between the radio systems shown in FIG. 4, and an image frequency. The figure which shows the example of a setting of the 1st local frequency when only the 1st radio | wireless system operate | moves in the composite receiver shown in FIG. 1, and the RF reception signal of a 2nd radio | wireless system mixes in a 1st radio | wireless system. The figure which shows the specific example of the frequency of each part for demonstrating the relationship between RF received signal leakage between radio | wireless systems in the example of a setting of the 1st local frequency shown in FIG. 6, and an image frequency. The figure which shows the example of a setting of the 1st local frequency when only the 2nd radio | wireless system operate | moves in the composite receiver shown in FIG. 1, and the RF reception signal of a 1st radio | wireless system mixes in a 2nd radio | wireless system. The figure which shows the specific example of the frequency of each part for demonstrating the relationship between RF reception signal leakage between radio | wireless systems in the example of a setting of the 1st local frequency shown in FIG. 8, and an image frequency. The block diagram which shows the structure of the composite transmission part in the radio | wireless communication apparatus which concerns on one Embodiment of this invention. The block diagram which shows the 1st specific example of the 1st local signal generator in one Embodiment of this invention. The figure which shows the specific example of the frequency of each part in the 1st local signal generator shown in FIG. The block diagram which shows the 2nd specific example of the 1st local signal generator in one Embodiment of this invention. The figure which shows the specific example of the frequency of each part in the 1st local signal generator shown in FIG. The block diagram which shows the structure of the composite receiver in the radio | wireless communication apparatus which concerns on other embodiment of this invention. The block diagram which shows the structure of the composite transmission part in the radio | wireless communication apparatus which concerns on other embodiment of this invention. The block diagram which shows the structure of the composite receiver in the radio | wireless communication apparatus which concerns on another embodiment of this invention. The figure which shows the specific example of the baseband signal output circuit in FIG. The block diagram which shows the structure of the composite receiver in the radio | wireless communication apparatus which concerns on another embodiment of this invention. The figure which shows the specific example of the baseband signal output circuit in FIG. The block diagram which shows the structure of the composite transmission part in the radio | wireless communication apparatus which concerns on another embodiment of this invention. The figure which shows the specific example of the baseband signal input circuit in FIG. The block diagram which shows the structure of the composite transmission part in the radio | wireless communication apparatus which concerns on another embodiment of this invention. The figure which shows the specific example of the baseband signal input circuit in FIG. The block diagram which shows the structure of the composite receiver which deform | transformed a part of FIG. The block diagram which shows the structure of the compound transmission part which deform | transformed a part of FIG.

Explanation of symbols

101, 102 ... band pass filter;
103, 104 ... low noise amplifier;
105, 106 ... frequency converter (down converter);
107 ... Frequency conversion local signal generator (first local signal generator);
108 ... band pass filter;
109, 110 ... mixer;
111 ... Local signal generator for quadrature demodulator (second local signal generator);
112 ... 90 ° phase shifter;
113 ... L frequency divider;
115, 117 ... baseband signal output circuit;
116, 118 ... control signals;
120 ... variable gain amplifier;
121, 122 ... low pass filter;
123, 124 ... A / D converter;
125: Baseband signal output circuit;
126 ... control signal;
201, 202 ... mixers;
203 ... Local signal generator for quadrature modulator (second local signal generator);
204 ... 90 ° phase shifter;
205 ... band pass filter;
206, 207 ... frequency converter;
208 ... Local signal generator for frequency conversion (first local signal generator);
213 ... L frequency divider;
220 ... Baseband signal input circuit 222, 223 ... D / A converter;
224, 225 ... low pass filter;
226. Variable gain amplifier

Claims (19)

In a wireless communication apparatus capable of supporting a plurality of wireless systems including the first and second wireless systems,
A local signal generator for generating a first local signal;
At least one frequency converter that converts the first RF reception signal corresponding to the first radio system and the second RF reception signal corresponding to the second radio system into an intermediate frequency signal of the same frequency using the first local signal; Comprising
When the frequency of the first RF reception signal is f _RF1 , the frequency of the second RF reception signal is f _RF2 , and the larger frequency bandwidth of each of the first radio system and the second radio system is BW, the first The frequency f _LO11 of one local signal is set to satisfy a condition of f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2 or f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2. A wireless communication device compatible with a wireless system. In a wireless communication apparatus capable of supporting a plurality of wireless systems including the first and second wireless systems,
A local signal generator for generating a first local signal;
At least one frequency converter that converts the first RF reception signal corresponding to the first radio system and the second RF reception signal corresponding to the second radio system into an intermediate frequency signal of the same frequency using the first local signal; Comprising
When the frequency of the first RF reception signal is f _RF1 , the frequency of the second RF reception signal is f _RF2 , and the larger one of the use frequency bandwidths of the first radio system and the second radio system is BW (however, f _RF1 > f _RF2 ), when only the first radio system operates, the frequency f _LO11 of the first local signal satisfies the condition of f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2, When only the second radio system is operated, the frequency f _LO11 of the first local signal can correspond to a plurality of radio systems set so as to satisfy the condition of f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2. Wireless communication device. In a wireless communication apparatus capable of supporting a plurality of wireless systems including the first and second wireless systems,
A local signal generator for generating a first local signal;
At least one frequency converter that converts the first RF reception signal corresponding to the first radio system and the second RF reception signal corresponding to the second radio system into an intermediate frequency signal of the same frequency using the first local signal; Comprising
When the frequency of the first RF reception signal is f _RF1 , the frequency of the second RF reception signal is f _RF2 , and the larger one of the use frequency bandwidths of the first radio system and the second radio system is BW (however, f _RF1 > f _RF2 ), when only the first radio system operates, the frequency f _LO11 of the first local signal satisfies the condition of f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2, When only the wireless system is operated, the frequency f _LO11 of the first local signal can correspond to a plurality of wireless systems set so as to satisfy the condition of f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2. Wireless communication device. In-phase baseband signal and quadrature baseband signal are generated by performing quadrature demodulation on the intermediate frequency signal using the second local signal and the third local signal having a phase difference of 90 ° with the second local signal. wireless communication device of any one of claims 1 to 3 orthogonal demodulator further comprising the. A first baseband signal and a second baseband signal are obtained by performing quadrature demodulation on the intermediate frequency signal using a second local signal and a third local signal having a phase difference of 90 ° with respect to the second local signal. An orthogonal demodulator that generates
Outputting the first baseband signal as an in-phase baseband signal, outputting the second baseband signal as a quadrature baseband signal, and outputting the first baseband signal as an in-phase baseband signal; the second baseband signal polarity inversion is caused in any one of claims 1 to 3 further comprising a one can be selected baseband signal output circuit of the second mode for outputting the quadrature baseband signal wirelessly Communication device. A first baseband signal and a second baseband signal are obtained by performing quadrature demodulation on the intermediate frequency signal using a second local signal and a fourth local signal having a phase difference of 90 ° with respect to the second local signal. An orthogonal demodulator that generates
Outputting the first baseband signal as an in-phase baseband signal, outputting the second baseband signal as a quadrature baseband signal, and outputting the first baseband signal as a quadrature baseband signal, wireless communication device of any one of claims 1 to 3 further comprising a one can be selected baseband signal output circuit of the second mode for outputting a second base band signal as an in-phase baseband signal. The radio communication apparatus according to claim 4 , further comprising an L frequency divider that divides the first local signal by L (L is an arbitrary integer) and generates the second local signal. Said frequency f _RF1 is in the range of 5.15GHz to 5.25 GHz, the frequency f _RF2 is in the range of 2.4GHz to 2.5 GHz, the frequency f _LO11 is 1 to claim or less or 3.85GHz or 3.75GHz 4. The wireless communication device according to any one of items 3 . Said frequency f _RF1 is in the range of 5.15GHz to 5.25 GHz, the frequency f _RF2 is in the range of 2.4GHz to 2.5 GHz, the L wireless communication apparatus according to claim 7, wherein a 3. In a wireless communication apparatus capable of supporting a plurality of wireless systems including the first and second wireless systems,
A local signal generator for generating a first local signal;
A frequency divider that divides the first local signal to generate a second local signal;
By performing quadrature modulation on the first baseband signal and the second baseband signal using a second local signal and a third local signal having a phase difference of 90 ° with respect to the second local signal, an intermediate frequency of a specific frequency is obtained. A quadrature modulator for generating a signal;
At least one frequency converter for converting the intermediate frequency signal into a first RF transmission signal corresponding to the first radio system and a second RF transmission signal corresponding to the second radio system using the first local signal. And
When the frequency of the first RF transmission signal is f _RF1 , the frequency of the second RF transmission signal is f _RF2 , and the larger frequency bandwidth of each of the first radio system and the second radio system is BW, the first The frequency f _LO11 of one local signal is set to satisfy a condition of f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2 or f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2. A wireless communication device compatible with a wireless system. In a wireless communication apparatus capable of supporting a plurality of wireless systems including the first and second wireless systems,
A local signal generator for generating a first local signal;
A frequency divider that divides the first local signal to generate a second local signal;
By performing quadrature modulation on the first baseband signal and the second baseband signal using a second local signal and a third local signal having a phase difference of 90 ° with respect to the second local signal, an intermediate frequency of a specific frequency is obtained. A quadrature modulator for generating a signal;
At least one frequency converter for converting the intermediate frequency signal into a first RF transmission signal corresponding to the first radio system and a second RF transmission signal corresponding to the second radio system using the first local signal. And
When the frequency of the first RF reception signal is f _RF1 , the frequency of the second RF reception signal is f _RF2 , and the larger one of the use frequency bandwidths of the first radio system and the second radio system is BW (however, f _RF1 > f _RF2 ), when only the first radio system operates, the frequency f _LO11 of the first local signal satisfies the condition of f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2, When only the second radio system is operated, the frequency f _LO11 of the first local signal can correspond to a plurality of radio systems set so as to satisfy the condition of f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2. Wireless communication device. In a wireless communication apparatus capable of supporting a plurality of wireless systems including the first and second wireless systems,
A local signal generator for generating a first local signal;
A frequency divider that divides the first local signal to generate a second local signal;
By performing quadrature modulation on the first baseband signal and the second baseband signal using a second local signal and a third local signal having a phase difference of 90 ° with respect to the second local signal, an intermediate frequency of a specific frequency is obtained. A quadrature modulator for generating a signal;
At least one frequency converter for converting the intermediate frequency signal into a first RF transmission signal corresponding to the first radio system and a second RF transmission signal corresponding to the second radio system using the first local signal. And
When the frequency of the first RF reception signal is f _RF1 , the frequency of the second RF reception signal is f _RF2 , and the larger one of the use frequency bandwidths of the first radio system and the second radio system is BW (however, f _RF1 > f _RF2 ), when only the first radio system operates, the frequency f _LO11 of the first local signal satisfies the condition of f _LO11 > (f _RF1 + f _RF2 ) / 2 + BW / 2, When only the wireless system is operated, the frequency f _LO11 of the first local signal can correspond to a plurality of wireless systems set so as to satisfy the condition of f _LO11 <(f _RF1 + f _RF2 ) / 2−BW / 2. Wireless communication device. A first mode for inputting an in-phase baseband signal and a quadrature baseband signal, outputting the in-phase baseband signal as the first baseband signal, and outputting the quadrature baseband signal as the second baseband signal; A baseband signal input circuit capable of selecting any one of a second mode for outputting an in-phase baseband signal as the first baseband signal, inverting the polarity of the quadrature baseband signal and outputting the inverted signal as the second baseband signal; The wireless communication device according to claim 10, further comprising: A first mode for inputting an in-phase baseband signal and a quadrature baseband signal, outputting the in-phase baseband signal as the first baseband signal, and outputting the quadrature baseband signal as the second baseband signal; A baseband signal input circuit capable of selecting any one of a second mode for outputting a quadrature baseband signal as the first baseband signal and outputting the in-phase baseband signal as the second baseband signal. Item 13. The wireless communication device according to any one of Items 10 to 12 . The local signal generator is
A signal source for generating an original local signal of frequency f _{LO 10,} the original local signal N divider (N is an arbitrary integer) and N divider to produce the divided local signal of a frequency f _{LO 10} / N to,
A multiplier that multiplies the original local signal and the _divided local signal, and a signal component having a frequency f _LO10 (1-1 / N) or f _LO10 (1 + 1 / N) included in the output signal of the multiplier. The wireless communication apparatus according to claim 1, further comprising: a generator that generates one local signal. The generator is
A first band pass filter for extracting a signal component of frequency f _LO10 (1-1 / N) from the output signal of the multiplier;
A second band pass filter for extracting a signal component of frequency f _LO10 (1 + 1 / N) from the output signal of the multiplier;
_Either the signal component of the frequency f _LO10 (1-1 / N) or the signal component of the frequency f _LO10 (1 + 1 / N) respectively extracted by the first bandpass filter and the second bandpass filter is used as the first bandpass filter. The wireless communication apparatus according to claim 15 , further comprising a selector that selects the local signal. The local signal generator is
A signal source for generating an original local signal of frequency f _LO10 ;
A first phase shifter for phase-shifting the original local signal to generate a first phase-shifting local signal and a second phase-shifting local signal having a phase difference of 90 ° from each other;
An N divider that _{divides the} original local signal by N (N is an arbitrary integer) to generate a _divided local signal having a frequency f _LO10 / N, and the _divided local signal is _shifted by 90 ° to each other. A second phase shifter for generating a third phase shift local signal and a fourth phase shift local signal having a phase difference;
A first multiplier for multiplying the first phase-shifted local signal and a third phase-shifted local signal;
A second multiplier for multiplying the second phase-shifted local signal and the fourth phase-shifted local signal;
By adding or subtracting the output signal of the first multiplier and the output signal of the second multiplier, the signal component of the frequency f _LO10 (1-1 / N) or f _LO10 (1 + 1 / N) is converted into the first local signal. The wireless communication device according to claim 1, further comprising: a generator that generates The generator is
Addition / subtraction for adding and subtracting the output signal of the first multiplier and the output signal of the second multiplier to generate signal components of frequencies f _LO10 (1-1 / N) and f _LO10 (1 + 1 / N) And
And a selector that selects either the signal component of the frequency f _LO10 (1-1 / N) or the signal component of the frequency f _LO10 (1 + 1 / N) generated by the adder / subtractor as the first local signal. Item 18. A wireless communication device according to Item 17 . The frequency f _{LO 10} of the original local signal is _{(f RF1 + f RF2) /} 2, the frequency f _{LO 10} / N of the frequency division local signal any one of the BW / 2 or more in a claim 15 or 17 The wireless communication device described.

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