KR19990078141A - Radio device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless device, comprising: dividing a first local oscillation signal of frequency f _LO1 [Hz] into third and fourth local oscillation signals of 90 degrees out of phase, respectively, and then frequency f _LO2 [Hz]. The second local oscillation signal is divided into fifth and sixth local oscillation signals having 90 degrees out of phase, respectively, and the result of multiplying the third local oscillation signal and the fifth local oscillation signal by the fourth local oscillation signal and the fifth local oscillation signal. The result of multiplying the local oscillation signal is added or subtracted to generate a local oscillation signal from which the image signal is removed.

Description

Wireless device {RADIO DEVICE}

The present invention relates to a wireless device such as a portable radio.

In recent years, the development of the mobile communication device represented by a mobile telephone is actively performed. These communication devices are required to be miniaturized and light weight, for example, because they are carried by a person or mounted on an automobile. For this reason, the monolithic IC (integrated circuit) for miniaturization and weight reduction is strongly demanded for the components which comprise such a radio apparatus compared with the conventional hybrid structure which connected many components. On the other hand, in addition to miniaturization of components, the low cost of the radio is required, IC technology is a technology connected to the low cost of the radio.

In such a wireless device, there is a conventional transmission / reception apparatus using a superheterodyne scheme, for example, a transmission / reception apparatus of a TDD (Time Division Duplex) system that divides transmission and reception by time. The configuration and operation will be described below. The two orthogonal baseband signals generated by the baseband signal generator are output through the appropriate band limiting filter and then output by the baseband signal processor. These two baseband signals are input to an orthogonal modulator consisting of a multiplier and an adder, and modulate a second local oscillation signal (frequency f _LO2 ). At this time, the second local oscillation signal is divided into two local oscillation signals orthogonal to the orthogonal modulator by 90 degrees or more and input to the orthogonal modulator. Such an intermediate frequency signal (IF signal) is generally input to the upconverter through a filter composed of a low pass filter or a band pass filter because it contains unnecessary high frequencies.

The up-converter multiplies the first local oscillation signal of the frequency (f _LO1 [Hz]) and the modulated signal (IF signal) to avoid the frequency f _LO1 + f _LO2 [Hz] or f _LO1 -f _LO2 [Hz]. Generates a radio frequency signal (RF signal). One of them becomes a desired wave and the other is an unnecessary image signal. When the RF signal of the frequency (f _LO1 + f _LO2 [Hz]) is a desired wave, the image signal is removed by an image removal band pass filter. The desired wave is amplified to the required power level by the power amplifier and radiated from the antenna via a transmit / receive switch.

In the receiver, the received RF signal is input to the low noise amplifier through an antenna, a transmission / reception switching switch, and a band pass filter. The received RF signal amplified by the low noise amplifier is input to the down converter through an image cancellation bandpass filter. The down converter multiplies the first local oscillation signal and the received signal to frequency convert the received signal into an IF signal. The IF signal is input to an orthogonal demodulator consisting of a splitter and a multiplier through a band pass filter. The local oscillation signal of the orthogonal frequency (f _LO2 [Hz]) is input to this orthogonal demodulator similarly to the transmitter. The outputs Ich (RX) and Qch (RX) of the quadrature demodulator demodulate the received signal input to the baseband processor.

According to the conventional radio apparatus described above, when the local oscillation signal is modulated by the baseband signal, the local oscillation signal is divided into two orthogonal signals by a 90 degree phase shifter and input to the quadrature modulator. Since this modulated signal (IF signal) generally contains unnecessary high frequencies, it is input to the upconverter after removing unnecessary high frequencies with a filter. This up-converter multiplies the first local oscillation signal of the frequency f _LO1 [Hz] and the modulated signal (IF signal) to avoid the frequency f _LO1 + f _LO2 [Hz] or f _LO1 -f _LO2 [Hz]. Generates a modulated signal (RF signal).

One of them becomes a desired wave and the other is an unnecessary image signal. An image removal filter is installed to remove this unnecessary image signal. Such image filters hinder the realization of miniaturization and low cost of wireless devices.

Accordingly, an object of the present invention is to provide a wireless device that realizes miniaturization and low cost by eliminating an externally attached image removal filter.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of a wireless device employing a direct conversion scheme for a transmission system and a heterodyne scheme for a reception system using a local oscillation signal generation circuit of an embodiment of the present invention.

2 is a circuit diagram of a local oscillation signal generation circuit according to an embodiment of the present invention;

3A to 3D are diagrams for explaining removal of an image signal;

4 (a) to 4 (c) show some specific circuit diagrams of the 90-degree or higher phase device used in the circuit of FIG.

5 is a circuit diagram of a local oscillation signal generating circuit according to another embodiment of the present invention;

6 is a detailed circuit diagram of the local oscillation signal generation circuit of FIG.

7 is another specific circuit diagram of the local oscillation signal generation circuit of FIG. 2;

8 is a detailed circuit diagram of the local oscillation signal generation circuit of FIG. 4;

9 is another specific circuit diagram of the local oscillation signal generation circuit of FIG. 4;

10 is a block diagram of a wireless device employing a local oscillation signal generation circuit according to another embodiment of the present invention and employing a direct conversion scheme in a transmission / reception system.

11 is a block diagram of a wireless device employing a local oscillation signal generation circuit according to another embodiment of the present invention and employing a direct conversion scheme in a transmission / reception system.

12 is a block diagram of a wireless device employing a local oscillation signal generation circuit according to another embodiment of the present invention and employing a direct conversion scheme in a transmission and reception system, and

FIG. 13 is a circuit diagram of a wireless device of the direct conversion method as another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

11: antenna 12: transmission and reception switch

14 low noise amplifier (LAN) 16 down converter

17: local oscillation signal generation circuit 19: quadrature demodulator

23: Quadrature Modulator 24: Filter

25: power amplifier (PA)

The invention provides an oscillation circuit for generating a first local oscillation signal of at least a first frequency f _LO1 [Hz] and a second local oscillation signal of a second frequency f _LO2 [Hz] and a first local oscillation signal. A first signal generation circuit for generating a third local oscillation signal and a fourth local oscillation signal 90 degrees out of phase with each other; and a fifth local oscillation signal and a sixth local oscillation signal 90 degrees out of phase with the second local oscillation signal; A local signal generation section comprising a second signal generation circuit for generating?, A multiplication of the third local oscillation signal and the fifth local oscillation signal, and a multiplication of the fourth local oscillation signal and the sixth local oscillation signal, A wireless device comprising a transmitter having a modulation function using a seventh local oscillation signal generated by adding or subtracting two multiplication results and a receiver having a demodulation function using the seventh local oscillation signal.

The present invention also provides an oscillation circuit for generating a first local oscillation signal of a first frequency f _LO1 [Hz] and a second local oscillation signal of a second frequency f _LO2 [Hz], and the first local oscillation. A first signal generation circuit for generating third and fourth local oscillation signals each having a 90 degree phase out of the signal and a second generating fifth and six local oscillation signals having a 90 degree phase different from the second local oscillating signal, respectively; A seventh local oscillation signal is generated by adding or subtracting the signal generation circuit, the result of multiplying the third local oscillation signal and the fifth local oscillation signal, and the result of multiplying the fourth local oscillation signal and the fifth local oscillation signal, Provided is a wireless device comprising an arithmetic unit which transmits the eighth and ninth local oscillation signals having different 90 ° phases generated using the seventh local oscillation signal as local oscillation signals to a transceiver.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described with reference to drawings.

According to the radio device of Fig. 1, an antenna 11 is supplied to a transmission / reception switching switch (RF switch (Tx / Rx switch)) 12 for switching the reception system and the transmission system of the radio device.

In the reception system, a transmission / reception switch (RF switch (Tx / Rx switch)) 12 is connected to the band pass filter (FIL3) 13, the low noise amplifier (LNA) 14, and the band pass filter (FIL4) 15. It is connected to the input terminal of the down converter 16. The other input terminal of this down converter 16 receives the first local oscillation signal fLO1 [Hz] from the local oscillation signal generation circuit 17. The output terminal of the down converter 16 is connected to an orthogonal demodulator 19 consisting of a divider and a multiplier through a band pass filter FIL5 18. The orthogonal demodulator 19 is further input with a second local oscillation signal having a frequency f _LO2 [Hz] orthogonal to the 90 degree _phaser 20. The output signals Ich (RX) and Qch (RX) of the quadrature demodulator 19 are inputted to the baseband processor (RX-BB) 21 to demodulate the received signal.

In the transmission system, the baseband signal processing unit (TX-BB) 22 passes through a quadrature modulator 23, a band pass filter (FIL11) 24, and a power amplifier (PA) 25 in order to transmit and receive a switching switch (RF switch ( TX / RX switch) 12).

In this transmission system, the local oscillation signal transmitted from the local oscillation signal generation circuit 17 is generated by the multiplication of the first local oscillation signal f _LO1 [Hz] and the second local oscillation signal f _LO2 [Hz]. It is a signal of frequency (f _LO1 + f _LO2 [Hz]). The image signal at the frequencies f _LO1 -f _LO2 [Hz] is removed by signal processing in the local oscillation signal generating circuit 17. Here, f _LO1 + f _LO2 is a desired local oscillation signal, but in some cases, f _LO1 -f _LO2 may be a desired local oscillation signal. In this case, f _LO1 + f _LO2 are removed by signal processing. Since the image signal is removed, signals having a frequency f _LO1 + f _LO2 [Hz] are orthogonal to each other through a 90-degree or more phase, and are output to the quadrature modulator 23.

Quadrature modulator 23 modulates a local oscillation signal of frequency (f _LO1 + f _LO2 [Hz]) by baseband signals Ich (RX) and Qch (TX). The modulated signal is radiated from the antenna 11 through a filter 24 composed of a low pass filter or a band pass filter, a power amplifier 25 and a transmission / reception switching switch 12. However, in principle, the filter 24 is unnecessary and may be removed if the characteristic is allowed.

Next, the local oscillation signal generation circuit 17 will be described with reference to FIG. According to FIG. 2, the ninety degree or more phaser 90-PS1 31 receives the first local oscillation signal of frequency f _LO1 [Hz] and outputs signals of cosω _LO1 t and sinω _LO1 t.

On the other hand, the phase shifter 90-PS2 32 receives the second local oscillation signal of the frequency f _LO2 [Hz] and outputs the signals of cosω _LO2 t and sinω _LO2 t. As shown by Equation 1, these signals are multiplied and subtracted to suppress an image signal of frequency (f _LO1 -f _LO2 [Hz]) and generate only a desired local oscillation signal of frequency f _LO1 + f _LO2 [Hz]. do.

In the case of actual manufacturing, phase error and amplitude error occurs due to manufacturing deviation of 90 degrees or more, and unnecessary image signal or local oscillation signal of frequency (f _LO1 ㅗㅗ [Hz]) and frequency (f _LO ㅗㅗ ₂ [Hz]). Leaks. However, even if these manufacturing variations are included, each unnecessary signal can be attenuated by 40 dB or more with respect to a desired signal.

The state of image removal in the above embodiment is shown in Figs. 3 (a), (b), (c) and (d).

3A and 3B show local oscillation signals of frequencies f _LO1 and f _LO2 , respectively. The local oscillation signals of frequencies f _LO1 and f _LO2 are multiplied to produce the signals shown in FIGS. 3C and 3D, respectively. The image signal components are removed by subtracting these signals.

Specific examples of the 90 degree or more group generally used in FIGS. 4 (a), 4 (b) and 4 (c) are shown. Although the phase shifter shown in Fig. 4A has a high phase accuracy, an amplitude error occurs due to manufacturing variation. The phase shifter of FIG. 4B has a high amplitude accuracy, but a phase error occurs due to manufacturing variation. The ideal phase of FIG. 4C has an amplifier capability, although the phase precision and the amplitude precision deteriorate due to manufacturing variation. Although each of these abnormal phases has characteristics, any of these may be used in the present invention as needed.

Signal processing of image rejection is possible with attenuation greater than 50 dB for the desired wave. However, in the signal processing, it may not be possible to suppress about 40 dB due to manufacturing variation. Even in this case, the leakage of the image signal and the local oscillation signal is sufficiently suppressed by using the narrow band frequency characteristic of the power amplifier 25 shown in FIG. In addition, it is possible to add a band pass filter by a spiral inductor and a capacitor in the IC behind the local oscillation signal generation circuit 17 to have a suppression of unnecessary waves with respect to a desired wave by 10 dB.

Therefore, the local oscillation signal generation circuit 17 shown in FIG. 2 makes it possible to suppress the image to eliminate the externally attached image removal filter.

In the local oscillation signal generation circuit 17 of the present invention, the local oscillation signal from which the image is removed is further divided by the orthogonal signal by the 90-PS3 or 33 degrees. Even if this 90 degree or more also uses the thing shown in FIG. 4, there is no problem in particular. All the circuits shown here can be ICized, and image signals can be suppressed without using an image removal filter of an external component. Therefore, the size and cost of the wireless unit can be reduced.

FIG. 5 shows a configuration of a local oscillation signal generation circuit modified from FIG. This local oscillation signal generation circuit does not require a 90 degree phase shifter (90-PS3 in FIG. 2) that generates a signal having a phase different from 90 degrees in the local oscillation signal whose image is suppressed, and instead adds a multiplier and an adder. Generate two orthogonal local oscillation signals. The signal processing of the newly added part with respect to FIG. 2 is shown in Equation 2 below.

Accordingly, it can be seen that Equations 1 and 2 are orthogonal to each other. Thereby, like the embodiment shown in FIG. 2, a desired local oscillation signal can be obtained without requiring an external image removal filter.

Hereinafter, the specific example of the structure of local oscillation signal generation which removed the image of this invention is shown.

FIG. 6 shows a circuit diagram specifically configured of the local oscillation signal generating circuit of the present invention shown in FIG. The resistance R shown in FIG. 4A to generate a signal 90 degrees or more from a signal of frequency f _LO1 [Hz] ( _{denoted as} ω _LO1 [= 2π f _LO1 ] in the drawing). ₁ ), an ideal group made of capacitor C ₁ is used. On the other hand, the transistors Q9-Q12 shown in Fig. 4C for generating a strange signal at 90 degrees from a signal of frequency f _LO2 [Hz] ( _{denoted as} ω _LO2 [= 2π f _LO2 ] in the figure). , An ideal group consisting of capacitor C3 and resistor R3 is used. A transistor (Q1-Q4, Q9, Q10), a resistor (R3), which multiplies one signal at a frequency f _LO1 [Hz] at least 90 degrees with one signal at a frequency f _LO2 [Hz] at least 90 degrees; A transistor that multiplies a double balance mixer (dBM) consisting of current sources (I3, I4) with one signal at frequencies above 90 degrees (f _LO1 [Hz]) and one signal at frequencies above 90 degrees (f _LO2 [Hz]). Subtraction of the result of multiplication is achieved by connecting one double balance mixer (dBM) consisting of (Q5-Q8, Q11, Q12), capacitor C3, and current sources I5, I6 in parallel. However, the load Z3 is a common load of two dBM, and the signal of the frequency f _LO2 [Hz] is 90 degrees or more in each dBM. The abnormal state shown in Fig. 4C is provided as described above. More than 90 degrees of the desired local oscillation signal generated by the parallel-connected dBM uses the phase shifter of Fig. 4A. Since the dBM or the 90 degrees or more used here can be integrated (IC), image suppression of the local oscillation signal input to the transmitter can be realized without using an external image removal filter.

FIG. 7 shows one more embodiment of the present invention shown in FIG. 2. The difference from the configuration of FIG. 6 is that a 90-degree or more group consisting of the resistor R4 and the capacitor C4 shown in FIG. 4B is used to perform 90 degrees or more of the frequency f _LO2 [Hz]. In this case, however, the devices connected between the emitters of the differential circuit on the lower side of dBM have the same impedance. In the present embodiment, the resistor R3 is used, but there is no particular problem as long as it is a linear impedance such as a capacitor or an inductor.

FIG. 8 shows a specific example of the local oscillation signal generating circuit of the present invention shown in FIG. Resistor R1 and capacitor C1 shown in FIG. 4A to generate a strange signal at 90 degrees from a signal of frequency f _LO1 [Hz] (omega _LO1 [= 2πf _LO1 ] in the drawing). The abnormal phase consisting of) is used. On the other hand, the frequency (f _LO2 [Hz] (the figure in the ω _LO2 [= 2π f _LO2] as a transistor (Q9-Q12 shown in (c) of Figure 4 to produce the 90 odd signal from the signal of the base material)), An ideal phase consisting of a capacitor C3 and a resistor R3 is used, and one signal of the frequency f _LO1 [Hz] that is 90 degrees or more and the other signal of the frequency f _LO2 [Hz] that is 90 degrees or more is used. double the one that is multiplied balanced mixer (dBM) and 90 more than the frequency (f _LO1 [Hz]) one signal with a frequency more than 90 degrees of the (f _LO1 [Hz]) double-balanced on the other side to multiply the one signal of the Mixers (dBM) are connected in parallel.

As a result, subtraction of each multiplication result is realized. One double balance mixer (dBM) consists of transistors (Q1-Q4, Q9, Q10), resistor (R3) and current sources (I3, I4), and the other double balance mixer (dBM) is transistor (Q5-Q8). , Q11, Q12), capacitor C3, and current sources I5, I6. However, as for load Z3, two dBM is a common load, and each dBM carries the signal of frequency _fLO2 [Hz] more than 90 degree | times. The abnormal state shown in Fig. 4C is provided. This embodiment is characterized by adding one further parallel connected dBM having the same circuit configuration as the parallel connected dBM shown above. However, at the base of these two parallel-connected dBM transistors Q1-Q4 and Q5-Q8, a local oscillation signal having a frequency f _LO1 [Hz] or more is formed so as to be a relationship between Equation 1 and Equation 2 above. It is input. As a result, the outputs of these two parallel-connected dBMs become local oscillation signals 90 degrees or more from each other. Similar to the circuits of Figs. 6 and 7, in this configuration, the image of the local oscillation signal can be suppressed without using an external image removal filter.

FIG. 9 shows one more specific example of the local oscillation signal generating circuit of the present invention shown in FIG. What is different from the configuration of FIG. 8 is to use a 90-degree or more group consisting of the resistor R4 and the capacitor C4 shown in FIG. 4B to perform more than 90 degrees of the frequency f _LO2 [Hz]. In this case, however, the devices connected between the emitters of the differential circuit on the lower side of dBM have the same impedance. In the present embodiment, the resistor R3 is used, but there is no particular problem as long as it is a linear impedance such as a capacitor or an inductor.

In this configuration, a signal is generated at a frequency f _LO1 + f _LO2 [Hz] or f _LO1 -f _LO2 [Hz] by suppressing the image signal using local oscillation signals of the frequencies f _LO1 [Hz] and f _LO2 [Hz]. Although the case of applying to the transmitter is described, this technique can be applied to the case of generating the local oscillation signal of the receiver. In this case, in principle, the received RF signal is directly converted into a baseband signal without using an image rejection filter.

In the above embodiment, the reception system employs a heterodyne system, and the transmission system employs a direct conversion system. Next, an embodiment in which both the transmission and reception systems employ the direct conversion method will be described.

10 illustrates a wireless device using frequencies f _LO1 + f _LO2 [Hz]. This radio apparatus is applied to a PHS or the like where transmission and reception use the same frequency. According to this, the local oscillation signal generator 17 supplies the local oscillation signal of the same frequency (f _LO1 + f _LO2 [Hz]) to the reception system orthogonal demodulator 19 and the transmission system orthogonal demodulator 23. This embodiment can generate local frequency signals for transmission and reception even without an image removal filter. In addition, the local oscillation signal generation unit 17 may supply a local oscillation signal having a frequency f _LO1 -f _LO2 [Hz] to the reception system quadrature demodulator 19 and the transmission system quadrature demodulator 23.

Next, an embodiment of a radio apparatus that can be used in a system in which the transmission frequency and the reception frequency are different will be described. In this embodiment, subtraction is added to change the local oscillation signal at the frequencies f _LO1 + f _LO2 into a local oscillation signal at the frequencies f _LO1 -f _LO2 . That is, when the desired frequency of the transmission system is f _LO1 + f _LO2 , the frequencies f _LO1 -f _LO2 are removed as image signals. On the other hand, in the receiver, the desired frequency becomes f _LO1 -f _LO2 and the image signal f _LO1 + f _LO2 is removed.

For example, in the embodiment of the transmission frequency f _TX [Hz]> receive frequency f _RX [Hz] shown in Fig. 11, the frequencies f _LO1 and f _LO2 are selected so that a frequency as shown in the following equation is obtained, Remove the image signal at frequencies f _LO1 -f _LO2 . This allows the generation and reception of local frequency signals without image filters.

f _LO1 + f _LO2 = f _TX

f _LO1 -f _LO2 = f _RX

In addition, as shown in Fig. 12, in the case of the embodiment of the reception frequency f _RX > transmission frequency f _TX , f _LO1 and f _LO2 are selected to obtain a frequency as shown in the following equation, and the frequency f _LO1 − f Remove the image signal from _LO2 ). Even in this case, a local frequency signal for transmission and reception may be generated without an image filter.

f _LO1 -f _LO2 = f _TX

f _LO1 + f _LO2 = f _RX

In the above embodiment, a bipolar transistor has been described as an active element. However, the same circuit can be configured by using a field effect transistor such as a MOSFET or a MESFET.

This method makes it possible to delete an image suppression filter by performing image suppression. On the other hand, an image suppression filter is a method unnecessary in principle, and there is a direct conversion method. The wireless unit using the direct conversion method converts an orthogonal I / Q baseband signal into an orthogonal I / Q baseband signal through one frequency conversion from an orthogonal I / Q baseband signal into an orthogonal I / Q baseband signal through a single frequency conversion from an RF signal. It has a demodulator.

FIG. 13 shows a block of a transmission / reception system according to the present invention in the case where a transmission frequency oscillator and a reception frequency oscillator are independently provided. According to this, in the reception system, the antenna 11 is connected to the low noise amplifier 14 through the transmission / reception switching switch (RF switch (TX / RX switch)) 12. The output of the low noise amplifier 14 is input to the baseband processing unit (RX-BB) 21 through the quadrature modulator 19.

In the transmission system, the baseband signal processing unit (TX-BB) 22 passes through a quadrature modulator 23 and a power amplifier (PA) 25 in order to a transmission / reception switch (RF switch (TX / RX switch)) 12. Connected. The reception system quadrature modulator 19 and the transmission system quadrature modulator 23 receive second local oscillation signals each having a frequency f _LO3 [Hz] orthogonal to the phase shifter 20 or more.

The above configuration has advantages such that the image suppression filter is unnecessary and can be used even when the frequencies of the transmission and reception are different, that the transceiver can be operated simultaneously, and that only two local oscillators are needed like the heterodyne method. This advantage is the same as the case of using the image suppression method.

According to the present invention, the externally attached image removal filter can be deleted, and the wireless part can be miniaturized and the price can be reduced.

Claims (21)

An oscillation circuit for generating a first local oscillation signal of at least a first frequency and a second local oscillation signal of a second frequency; a third local oscillation signal and a fourth local oscillation signal that are 90 degrees out of phase from the first local oscillation signal; A local signal generator comprising: a first signal generation circuit for generating a second signal; and a second signal generation circuit for generating a fifth local oscillation signal and a sixth local oscillation signal that are 90 degrees out of phase with each other in the second local oscillation signal; And A seventh local oscillation generated by multiplying the third local oscillation signal with the fifth local oscillation signal and multiplying the fourth local oscillation signal with the sixth local oscillation signal, and then adding or subtracting these two multiplication results; And at least one of a transmitter having a modulation function using a signal and a receiver having a demodulation function using the seventh local oscillation signal. The method of claim 1, The transmitter uses a seventh local oscillation signal generated by subtracting the third and fifth multiplication results and the fourth and sixth multiplication results, and the receiver uses the third and fifth multiplication results and the fourth. And demodulation and demodulation using the seventh local oscillation signal obtained by adding the sixth multiplication result. The method of claim 1, The transmitter uses a seventh local oscillation signal generated by adding the third and fifth multiplication results and the fourth and sixth multiplication results, and the receiver uses the third and fifth multiplication results and the fourth. And demodulation and demodulation using a seventh local oscillation signal obtained by subtracting a sixth multiplication result. The method of claim 1, Means for generating the eighth and ninth local oscillation signals that are 90 degrees out of phase with the seventh local oscillation signal, and having two baseband signals or modulation signals orthogonal to each other and the eighth and ninth local oscillating signals; And at least one of a transmitter for generating a modulated signal by using or a receiver for demodulating by using the eighth and ninth local oscillating signals. The method of claim 4, wherein The transmitter uses a seventh local oscillation signal generated by subtracting the third and fifth multiplication results and the fourth and sixth multiplication results, and the receiver uses the third and fifth multiplication results and the fourth. And modulation and demodulation using the seventh local oscillation signal obtained by adding the sixth multiplication result. The method of claim 4, wherein The transmitter uses a seventh local oscillation signal generated by adding the third and fifth multiplication results and the fourth and sixth multiplication results, and the receiver uses the third and fifth multiplication results and the fifth. And demodulating and demodulating using the seventh local oscillation signal obtained by subtracting the fourth and sixth multiplication results. The method of claim 1, ICized first double balance mixer performing multiplication of the third local oscillation signal and the fifth local oscillation signal; and ICized second double balance mixer performing multiplication of the fourth local oscillation signal and the sixth local oscillation signal. And a computing section constituted by means for connecting the first and second double balance mixers in parallel to add or subtract these two multiplication results. The method of claim 1, After multiplying the third local oscillation signal by the sixth local oscillation signal and multiplying the fourth local oscillation signal by the fifth local oscillation signal, two multiplication results are added or subtracted to generate the multiplication result. Means for generating an eighth local oscillation signal that is 90 degrees out of phase with the local oscillation signal, using two baseband signals or modulation signals orthogonal to the seventh local oscillation signal and the eighth local oscillation signal And at least one of a transmitter for generating a modulated signal or a receiver for demodulating using the seventh and eighth local oscillation signals. The method of claim 8, The transmitter uses a seventh local oscillation signal generated by subtracting the third and sixth multiplication results and the fourth and fifth multiplication results, and the receiver uses the third and sixth multiplication results and the fourth. And demodulation / demodulation using the seventh local oscillation signal obtained by adding the fifth multiplication result. The method of claim 8, The transmitter uses a seventh local oscillation signal generated by adding the third and sixth multiplication results and the fourth and fifth multiplication results, and the receiving unit uses the third and sixth multiplication results and the third multiplication result. And modulating using the seventh local oscillation signal obtained by subtracting the fourth and fifth multiplication results. The method of claim 8, ICized first double balance mixer for multiplying the third local oscillation signal and the fifth local oscillation signal; and ICized second double balance mixer for multiplying the fourth local oscillation signal and the sixth local oscillation signal; Means for connecting the first and second double balance mixers in parallel to add or subtract two multiplication results, and an ICized third double balance mixer for multiplying the third local oscillation signal and the sixth local oscillation signal; And a fourth IC balanced double mixer for multiplying the fourth local oscillation signal and the fifth local oscillation signal, and means for connecting the third and fourth double balance mixers in parallel to add or subtract these multiplication results. Wireless device having a calculation unit configured. An oscillation circuit for generating a first local oscillation signal at a first frequency and a second local oscillation signal at a second frequency; A first signal generation circuit for generating third and fourth local oscillation signals that are 90 degrees out of phase with the first local oscillation signal; A second signal generation circuit for generating fifth and sixth local oscillation signals that are 90 degrees out of phase with the second local oscillation signal; A third signal generation circuit for generating a seventh local oscillation signal by adding or subtracting a result of multiplying the third local oscillation signal by the fifth local oscillation signal and a result of multiplying the fourth local oscillation signal with the sixth local oscillation signal; A fourth signal generation circuit configured to generate the eighth and ninth local oscillation signals that are 90 degrees out of phase with the seventh local oscillation signal; A transmitter having a modulation function using the eighth and ninth local oscillation signals; And And a receiver having a demodulation function using the eighth and ninth local oscillation signals. The method of claim 12, An ICized first double balance mixer for multiplying the third local oscillation signal and the fifth local oscillation signal; and an ICized second double balance mixer for multiplying the fourth local oscillation signal and the sixth local oscillation signal; And a computing section constituted by means for connecting the first and second double balance mixers in parallel to add or subtract these two multiplication results. The method of claim 12, After multiplying the third local oscillation signal with the sixth local oscillation signal and multiplying the fourth local oscillation signal with the fifth local oscillation signal, two multiplication results are added or subtracted to generate the multiplication result, and the seventh Means for generating an eighth local oscillation signal that is 90 degrees out of phase with the local oscillation signal, using two baseband signals or modulation signals orthogonal to the seventh local oscillation signal and the eighth local oscillation signal And at least one of a transmitter for generating a modulated signal or a receiver for demodulating using the modulated signal and the seventh and eighth local oscillation signals. The method of claim 14, ICized first double balance mixer for multiplying the third local oscillation signal and the fifth local oscillation signal; and ICized second double balance mixer for multiplying the fourth local oscillation signal and the sixth local oscillation signal; and Means for connecting the first and second double balance mixers in parallel to add or subtract two multiplication results, and an ICized third double balance mixer for multiplying the third local oscillation signal and the sixth local oscillation signal; And an ICized double balance mixer for multiplying the fourth local oscillation signal and the fifth local oscillation signal and means for connecting the third and fourth double balance mixers in parallel to add or subtract these multiplication results. Wireless device having a calculation unit configured. A local signal generator for generating a first local oscillation signal at a first frequency and a second local oscillation signal at a second frequency; A splitter for dividing the first local oscillating signal into third and fourth local oscillating signals having 90 degrees out of phase, respectively, and the second local oscillating signal divided into fifth and sixth local oscillating signals having 90 degrees out of phase, respectively. ; And Computing unit that adds or subtracts the result of multiplying the third local oscillation signal and the fifth local oscillation signal and the result of multiplying the fourth local oscillation signal and the sixth local oscillation signal to generate a local oscillation signal from which unnecessary image signals are removed Wireless device, characterized in that consisting of. A local signal generator for generating a first local oscillation signal at a first frequency and a second local oscillation signal at a second frequency; A splitter for dividing the first local oscillating signal into third and fourth local oscillating signals having 90 degrees out of phase, respectively, and the second local oscillating signal divided into fifth and sixth local oscillating signals having 90 degrees out of phase, respectively. ; To generate a local oscillation signal from which unnecessary image signals are removed, a result of multiplying the third local oscillation signal and the fifth local oscillation signal and the result of multiplying the fourth local oscillation signal and the sixth local oscillation signal are added or subtracted. And a computing unit for generating a local oscillation signal, and transmitting the eighth and ninth local oscillation signals, which are generated by using the seventh local oscillation signal, to the optical reception unit as local oscillation signals. Wireless device. A transmitter using a direct conversion method; A receiver using a direct conversion method; And And a local oscillation signal generator for outputting first and second local oscillation signals to the transmitter and the receiver. The method of claim 18, The local oscillation signal generator may include a local oscillation signal of the same frequency generated by adding or subtracting an oscillation signal having a first frequency and a second frequency when the transmitter and the receiver use the same frequency. And outputting to the receiving unit. The method of claim 18, When the transmitter uses a higher frequency than the receiver, the local oscillation signal generator outputs a local oscillation signal generated by adding a frequency from local oscillation signals of first and second frequencies to the transmitter, and the first and the second. And outputting a local oscillation signal generated by subtracting a frequency from a local oscillation signal of two frequencies to the receiver. The method of claim 18, When the transmitter uses a lower frequency than the receiver, the local oscillation signal generator outputs a local oscillation signal generated by subtracting a frequency from local oscillation signals of first and second frequencies to the transmitter, and the first and the second. And outputting, to the receiver, a local oscillation signal generated by adding a frequency to a local oscillation signal of two frequencies.