JPH11355168A - Image rejection mixer and radio equipment provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an IF signal, from which an image signal is removed, even when two communication bands to be used are of higher and lower frequencies than a local signal frequency. SOLUTION: Local signals having the mutual phase difference of 90 deg. at a local phase shifter 112 are respectively multiplied by two received RF signals distributed by a distributor 111 by multipliers 113 and 114 and the results are converted into IF signals. Then, the phase of one of two If signals provided by this conversion is advanced by 45 deg. by an IF phase shifter 115 and the phase of the other signal is delayed by 45 deg. by an IF phase shifter 116. While using these signals, an adder 117 and a subtracter 118 respectively perform adding synthesization and subtracting synthesization. Corresponding to whether the communication band to be used is higher or lower than the frequency of the local signal, any one of outputs from the adder 117 and subtrascter 118 is selectively outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image rejection mixer for canceling an image signal that becomes an interference wave when down-converting an RF signal received from a communication partner station, and to a radio equipped with the mixer.

[0002]

2. Description of the Related Art In general, a receiving section of a radio device such as a mobile communication device is provided with a down converter for multiplying a received signal by a local signal and converting the received signal to a frequency such as an IF signal or a BB signal. However, as shown in FIG. 21, when a desired signal and an image signal at a target position are input to the down converter centering on the local signal on the frequency axis, the image signal is multiplied by the local signal to be the same as the desired signal. The frequency is converted to an interference wave.

Therefore, a filter for removing an image signal from a received signal is provided at a stage prior to the input of the downconverter. However, if this filter is provided, the receiver becomes larger and more expensive. Such an image rejection mixer is used.

The conventional image rejection mixer shown in FIG. 1 includes a reception distribution unit 511 for distributing a reception signal (a desired signal, an image signal, or the like) input from a reception signal input terminal 501 into two, and a local signal input terminal. 502
Local phase shifter 5 for distributing and shifting the input local signal into two signals having a phase difference of 90 degrees from each other.
And multiplication means 513 and 514 for multiplying the received signal distributed to the reception distribution means 511 by the local signal distributed by the received signal distribution means 512 to perform frequency conversion.
IF phase shifting means 515 and 516 for shifting the multiplied outputs frequency-converted by the multiplying means 513 and 514 so that the difference between the phase shift amounts becomes 90 degrees. At 516, an adder 517 for adding and synthesizing the two IF phase-shifted outputs that are phase-shifted so as to have a phase difference of 90 degrees from each other is provided.

According to the image rejection mixer, only a signal having a frequency higher than the local signal frequency is output. That is, it is an image rejection mixer used when the desired signal frequency is higher than the local signal frequency.

Next, referring to FIGS. 23 to 36, FIG.
The operation of the rejection mixer shown in (1) will be described both when the desired signal frequency is higher and lower than the local signal frequency.

In the following description, cos (ωLot)
Is a signal of a local frequency, cos (ωIFt) is a signal of an IF frequency, and it is assumed that the amplitude of a desired signal, an image signal, and a local signal input to a local signal input terminal input to a reception signal input terminal is 1. I do.

In FIG. 22, a reception signal input terminal 301
The received signal including the desired signal and the image signal input to the receiving device is divided into two by the receiving / distributing unit 311, and the divided signals are input to the receiving signal input terminals of the multiplying units 313 and 314.

The desired signal and image signal at this time are expressed by the following equations. The vector diagram at this time is shown in FIG. 23 (when the desired signal frequency is higher than the local signal frequency), and FIG.
4 (when the desired signal frequency is lower than the local signal frequency).

[0010]

(Equation 1)

On the other hand, the local signal input from the local signal input terminal 302 is distributed and phase-shifted by the local phase shifter 312 into two signals having a phase difference of 90 degrees from each other. Input to the input terminal.

The local signal at this time is expressed by the following equation.
The vector diagram at this time is shown in FIG. 25 (when the desired signal frequency is higher than the local signal frequency) and in FIG. 26 (when the desired signal frequency is lower than the local signal frequency).

[0013]

(Equation 2)

The desired signal, image signal and local signal input to the multiplying means 313 and 314 are multiplied.
Of these, the multiplication result of the multiplication means 313 is
15 and the multiplication result of the multiplication means 314 is output to the IF phase shift means 316.

The desired signal and the image signal at this time are expressed by the following equations.

(Equation 3)

FIG. 27 shows a vector diagram of the multiplication result of the multiplication means 313 when the desired signal frequency is higher than the local signal frequency, and FIG. 28 shows a vector diagram of the multiplication result of the multiplication means 314.

FIG. 29 shows a vector diagram of the multiplication result of the multiplication means 313 when the desired signal frequency is lower than the local signal frequency, and FIG. 30 shows a vector diagram of the multiplication result of the multiplication means 314.

The IF phase shift means 315 and 316 correspond to the multiplication means 313 and 3 corresponding to each other such that the difference between the phase shift amounts is 90 degrees, for example, a phase shift of +45 degrees and a phase shift of -45 degrees.
14 are phase shifted. At this time, the desired signal and the image signal included in the outputs of the IF phase shift means 315 and 316 are expressed by the following equations.

[0019]

(Equation 4)

FIG. 31 shows a vector diagram of the multiplication result of the IF phase shift means 315 when the desired signal frequency is higher than the local signal frequency, and FIG. 32 shows a vector diagram of the multiplication result of the IF phase shift means 316. .

FIG. 33 shows a vector diagram of the multiplication result of the IF phase shift means 315 when the desired signal frequency is lower than the local signal frequency, and FIG. 34 shows a vector diagram of the multiplication result of the IF phase shift means 316. .

The signals phase-shifted by the IF phase shifting means 315 and 316 are input to the adding means 317, added and synthesized, and output from the IF signal output terminal 303.
The desired signal and image signal at this time are expressed by the following equations.

[0023]

(Equation 5)

The vector diagrams at this time are shown in FIG. 35 (when the desired signal frequency is higher than the local signal frequency) and FIG. 36 (when the desired signal frequency is lower than the local signal frequency).

As described above, the conventional image rejection mixer outputs only the desired signal when the desired signal frequency is higher than the local signal frequency, but outputs the desired signal when the desired signal frequency is lower than the local signal frequency. FIG.
As shown in (1), conversely, the desired signal is canceled and only the image signal is output.

Therefore, if the desired signal frequency is lower than the local signal frequency, the phase shift direction as shown in FIG.
An image rejection mixer inverted from 2 must be used.

Therefore, in order to cope with the desired signals in the two communication bands on the high side and the low side with respect to the local signal frequency, for example, the image rejection mixers 501 and 502 are used as shown in FIG. The configuration includes the switch 503 for selecting the output of the mixer in accordance with the signal band, and the radio becomes large and expensive.

[0028]

In a conventional image rejection mixer, an RF signal in a communication band higher in frequency than the frequency of a local signal and an RF signal in a communication band in a lower frequency are selectively switched and received. In such a case, there has been a problem that the image signal cannot be canceled for one of the communication bands, or the configuration becomes large even if it is possible.

The present invention has been made to solve the above problem, and selectively switches between an RF signal in a communication band higher in frequency than the frequency of a local signal and an RF signal in a communication band in a lower frequency. To provide an image rejection mixer capable of canceling an image signal and down-converting a desired signal in any communication band with a relatively simple configuration, and a wireless device including the mixer. And

[0030]

In order to achieve the above-mentioned object, an image rejection mixer according to the present invention and a radio equipped with the mixer distribute an RF signal to two RF signals RF1 and RF2. RF distribution means;
Local phase shift distribution means for distributing the local signal into two local signals Lo1 and Lo2 having a phase difference of 90 ° from each other; RF signal RF1, first multiplication means for multiplying local signal Lo1, and RF signal RF2, second multiplication means for multiplying the local signal Lo2, first phase shift means for advancing the phase of the multiplication result of the first multiplication means by α ゜, and phase of the multiplication result of the second multiplication means , A phase shift result of the first phase shift means, an addition means for adding and synthesizing a phase shift result of the second phase shift means, and a first phase shift means. Subtracting means for subtracting and synthesizing the phase shift result of the second phase shifting means from the phase shifting result of the phase means; and adding means when the frequency of the desired signal included in the RF signal is higher than the frequency of the local signal. Selectively output the addition result, while being included in the RF signal When the frequency of the desired signal is lower than the frequency of the local signal, a signal switching means for selectively outputting the result of the subtraction by the subtracting means is provided.

In the image rejection mixer having the above-described configuration and the wireless device including the mixer, the two-divided RF
Each of the signals is multiplied by a local signal having a phase difference of 90 ° to convert the signal into an IF signal. Then, of the two IF signals obtained by this conversion, the phase of one signal is advanced by α ゜ and the other phase is delayed by 90 ° -α ゜, and the addition and subtraction synthesis are performed using these signals.

That is, by performing both addition and subtraction synthesis, whether the RF signal frequency is higher or lower than the local signal frequency, one of the synthesized outputs (IF signal) cancels the image signal. Signal.

Then, depending on whether the frequency of the desired signal included in the RF signal is higher or lower than the frequency of the local signal,
That is, the IF signal from which the image signal is canceled is selectively output according to the communication band to be used.

Therefore, according to the image rejection mixer having the above-described configuration and the radio including the mixer, the RF signal in the communication band higher in frequency than the frequency of the local signal and the RF signal in the communication band lower in frequency are used. In the case of selectively switching and receiving, it is possible to cancel an image signal and down-convert a desired signal in any communication band.

Further, the image rejection mixer according to the present invention and the radio having the mixer are provided with an RF
RF phase shift distribution means for distributing a signal to two RF signals RF1 and RF2 having a phase difference of 90 ° from each other, local distribution means for distributing a local signal to two local signals Lo1 and Lo2, and RF signal RF1 , A first multiplication means for multiplying by the local signal Lo1, and an RF signal RF2
, A second multiplication means for multiplying the local signal Lo2, a first phase shift means for advancing the phase of the multiplication result of the first multiplication means by α ゜, and a phase of the multiplication result of the second multiplication means. 9
Second phase shifting means for delaying 0 ° -α °, adding means for adding and synthesizing the phase shift result of the first phase shifting means and the phase shifting result of the second phase shifting means, and first phase shifting means From the phase shift result of the means, the second
Subtraction means for subtracting and combining the phase shift result of the phase shift means of
When the frequency of the desired signal included in the signal is higher than the frequency of the local signal, the addition result of the adding means is selectively output. On the other hand, when the frequency of the desired signal included in the RF signal is lower than the frequency of the local signal, And signal switching means for selectively outputting the subtraction result of the subtraction means.

In the image rejection mixer having the above-described configuration and the radio including the mixer, the received RF signal is divided into two so as to have a phase difference of 90 ° from each other, and a local signal is divided into each of the two RF signals. Multiply and convert to an IF signal. And 2 obtained by this conversion
Of the two IF signals, the phase of one signal is advanced by α ゜ and the other phase is delayed by 90 ° -α ゜, and addition and subtraction synthesis are performed using these signals.

That is, by performing both addition synthesis and subtraction synthesis, even if the frequency of the RF signal is higher or lower than the frequency of the local signal, one of the synthesized outputs (IF signal) cancels the image signal. Signal.

Then, depending on whether the frequency of the desired signal included in the RF signal is higher or lower than the frequency of the local signal,
That is, the IF signal from which the image signal is canceled is selectively output according to the communication band to be used.

Therefore, according to the image rejection mixer having the above-described configuration and the radio including the mixer, the RF signal in the communication band higher in frequency than the frequency of the local signal and the RF signal in the communication band lower in frequency are used. In the case of selectively switching and receiving, it is possible to cancel an image signal and down-convert a desired signal in any communication band.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an image rejection mixer according to an embodiment of the present invention. This image rejection mixer is provided, for example, in a reception RF signal processing unit of a dual band wireless device that selectively uses two communication bands.

Reference numeral 101 denotes a reception signal input terminal to which reception RF signals of two communication bands including an unnecessary signal such as an image signal in addition to a desired signal are input.

Note that the two communication bands here are a communication band of a higher frequency band and a communication band of a lower frequency band than the frequency of a local signal input from a local signal input terminal 102 described later.

Then, the received RF signal input from the received signal input terminal 101 is split by the splitter 111 into two received RF signals. One of the two received RF signals is input to the multiplier 113 and the other is the multiplier 1
14 is input.

Reference numeral 102 denotes a local signal input terminal for inputting a local signal generated by an oscillator (not shown). The local signal input from the local signal input terminal 102 is input to the local phase shifter 112 (90 °) and is divided into two local signals having a phase difference of 90 ° from each other.

Then, of these two local signals,
The local signal whose phase is advanced is calculated by the multiplier 11
The local signal whose phase is delayed is input to the multiplier 114.

The multiplier 113 multiplies the received RF signal from the distributor 111 by the local signal from the local phase shifter 112 to convert the frequency of the received RF signal into an IF signal. The signal is input to the phase shifter 115 (+ 45 °).

Similarly, the multiplier 114 multiplies the received RF signal from the distributor 111 by the local signal from the local phase shifter 112 to convert the frequency of the received RF signal into an IF signal. The signal is converted to an IF phase shifter 116 (−4
5)).

IF phase shifter 115 advances the phase of the IF signal from multiplier 113 by 45 °, and inputs the result to adder 117 and subtractor 118. On the other hand, IF phase shifter 116 delays the phase of the IF signal from multiplier 114 by 45 °, and inputs the result to adder 117 and subtractor 118.

The adder 117 adds and combines the output of the IF phase shifter 115 and the output of the IF phase shifter 116, and inputs the combined result to the switch 119. On the other hand, the subtractor 118
The output of the IF phase shifter 115 and the output of the IF phase shifter 118 are subtracted and synthesized, and the synthesis result is input to the switch 119.

The switch 119 has a switching signal input terminal 104
In response to a switching instruction from a control unit (not shown) input from the control unit, one of the synthesis result of the adder 117 and the synthesis result of the subtracter 118 is selectively output to the IF output terminal 10.
The signal is input to an IF signal processing unit (not shown) at the subsequent stage through 3.

Next, the operation of the image rejection mixer having the above configuration will be described with reference to FIGS.
The reception RF signal input to the reception signal input terminal 101 is
The two parts are distributed by the distributor 111. Then, the distributed signals are input to multipliers 113 and 114. At this time, the reception R input to multipliers 113 and 114 respectively
The desired signal and the image signal included in the F signal are represented by the following equations, respectively.

[0052]

(Equation 6)

The received RF input to the multiplier 113
FIG. 2 shows a vector diagram of the signal, and FIG. 3 shows a vector diagram of the received RF signal input to the multiplier 114. It should be noted that the phase of the desired signal and the phase of the image signal are the same whether the frequency of the desired signal is higher or lower than the frequency of the local signal.

On the other hand, the local signal input from the local signal input terminal 102 is input to the local phase shifter 112, and is divided into two local signals having a phase difference of 90 ° from each other. The other local signal is input to multiplier 113, while the local signal whose phase is delayed is input to multiplier 114.

At this time, the local signals input to the multipliers 113 and 114 are expressed by the following equations, respectively.

[0056]

(Equation 7)

FIG. 4 is a vector diagram of the local signal input to the multiplier 113, and FIG. 5 is a vector diagram of the local signal input to the multiplier 114. Note that the phase of each local signal is the same regardless of whether the frequency of the desired signal is higher or lower than the frequency of the local signal, and is shown in FIGS. 4 and 5.

Then, in the multiplier 113, the divider 111
The received RF signal (desired signal, image signal) is multiplied by the local signal, and the received RF signal is
Down-convert to F signal. The IF signal obtained by this frequency conversion is input to IF phase shifter 115.

Similarly, in the multiplier 114, the divider 111
The received RF signal (desired signal, image signal) is multiplied by the local signal, and the received RF signal is
Down-convert to F signal. The IF signal obtained by this frequency conversion is input to IF phase shifter 116.

The IF phase shifter 115, IF
The desired signal and the image signal included in the IF signal input to the phase shifter 116 are expressed by the following equations, respectively.

[0061]

(Equation 8)

Here, when the frequency of the desired signal is higher than the frequency of the local signal, a vector diagram of the desired signal and the image signal included in the IF signal obtained by the multiplier 113 is shown in FIG. I
FIG. 7 shows vector diagrams of the desired signal and the image signal included in the F signal, respectively.

When the frequency of the desired signal is lower than the frequency of the local signal, a vector diagram of the desired signal and the image signal included in the IF signal obtained by the multiplier 113 is shown in FIG. IF
FIG. 9 shows vector diagrams of the desired signal and the image signal included in the signal.

The IF signal input to IF phase shifter 115 is advanced in phase by 45 ° by IF phase shifter 115,
On the other hand, the IF signal input to the IF phase shifter 116 is
The phase is delayed by 45 ° by the phase shifter 116.

The IF phase shifter 115 and the IF phase shifter 11
The desired signal and the image signal included in the IF signals respectively shifted by 6 are expressed by the following equations.

[0066]

(Equation 9)

Here, when the frequency of the desired signal is higher than the frequency of the local signal, a vector diagram of the desired signal and the image signal included in the IF signal shifted by the IF phase shifter 115 is shown in FIG. FIG. 11 shows vector diagrams of the desired signal and the image signal included in the IF signal shifted by the phase shifter 116, respectively.

When the frequency of the desired signal is lower than the frequency of the local signal, a vector diagram of the desired signal and the image signal included in the IF signal shifted by the IF phase shifter 115 is shown in FIG. FIG. 13 shows vector diagrams of the desired signal and the image signal included in the IF signal shifted by the phase shifter 116, respectively.

The IF signals phase-shifted by IF phase shifter 115 and IF phase shifter 116 are input to adder 117 and subtractor 118, respectively, where addition synthesis and subtraction synthesis are performed. Are input to the switch 119, respectively.

The desired signal and the image signal included in the IF signal added and combined in the adder 117 and the IF signal subtracted and combined in the subtracter 118 are expressed by the following equations, respectively.

[0071]

(Equation 10)

Here, when the frequency of the desired signal is higher than the frequency of the local signal, a vector diagram of the desired signal and the image signal included in the IF signal added and synthesized by the adder 117 is shown in FIG. FIG. 15 is a vector diagram of the desired signal and the image signal included in the IF signal subtracted and synthesized in the above.

When the frequency of the desired signal is lower than the frequency of the local signal, a vector diagram of the desired signal and the image signal included in the IF signal added and synthesized by the adder 117 is shown in FIG. FIG. 17 shows vector diagrams of the desired signal and the image signal included in the IF signal subjected to the subtraction synthesis.

Therefore, when the frequency of the desired signal is higher than the frequency of the local signal, the IF signal from which the image signal has been canceled is input to the switch 119 and the desired signal is output from the subtractor 118 to the switch 119. The canceled IF signal is input.

On the other hand, when the frequency of the desired signal is lower than the frequency of the local signal, switch 119 has adder 1
The IF signal from which the desired signal is canceled is input from 17, and the IF signal from which the image signal is canceled is input from the subtracter 118.

Then, the control unit controls the switch 119 through the switch signal input terminal 104 according to the communication band of the desired signal.
In response to this, the switch 119 selectively outputs one of the combined result of the adder 117 and the combined result of the subtractor 118 through the IF output terminal 103 to a subsequent IF signal processing unit. To enter.

That is, if the communication band to be used is higher than the frequency of the local signal, the control unit
And giving an instruction to the switch 119 so as to output the IF signal from which the image signal has been cancelled, which is input from 17;
On the other hand, when the communication band to be used uses a communication band lower than the frequency of the local signal, an instruction is given to the switch 119 so as to output the IF signal input from the subtractor 118 from which the image signal has been canceled. .

As described above, in the image rejection mixer having the above configuration, the received RF signal divided into two
Each local signal having a phase difference of 90 ° is multiplied and converted into an IF signal. Then, of the two IF signals obtained by this conversion, the phase of one signal is advanced by 45 ° (α ゜), and the other phase is delayed by 45 ° (90 ° -α ゜), and added using these signals. Performs composition and subtraction composition.

That is, by performing both addition and subtraction synthesis, whether the frequency of the received RF signal is higher or lower than the frequency of the local signal, one of the synthesized outputs (IF signal) is output as an image signal. The signal becomes a canceled signal.

Then, depending on whether the frequency of the desired signal included in the received RF signal is higher or lower than the frequency of the local signal, that is, according to the communication band to be used, the IF signal from which the image signal is canceled is selectively selected. Output.

Therefore, according to the image rejection mixer having the above-described configuration, one of the above-described addition / combination result and the subtraction / combination result depends on whether the communication band to be used is higher or lower than the frequency of the local signal. Since the image signal is canceled, the image signal is canceled by selectively using the synthesis result in accordance with the communication band to be used, even when the communication band to be used includes one higher and lower than the local signal frequency. IF
A signal can be obtained.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the IF
In the phase shifter 115, the phase of the IF signal from the multiplier 113 is advanced by 45 °, while, in the IF phase shifter 118, the phase of the IF signal from the multiplier 114 is delayed by 45 °. Instead, as shown in FIG.
In phase shifter 215 (−45 °), the phase of the IF signal from multiplier 113 is delayed by 45 °, while IF phase shifter 2
At 16 (+ 45 °), the phase of the IF signal from the multiplier 114 may be advanced by 45 °.

That is, in FIG. 1, the IF phase shifter 11
5, 116, one IF phase shifter advances the phase of the IF signal from the corresponding multiplier by α ゜, and the other IF phase shifter
The same effect can be obtained by delaying the phase of the IF signal from the corresponding multiplier by 90 ° -α ° in the F phase shifter.

In the above embodiment, the local phase shifter 112 distributes the local signal into two local signals having a phase difference of 90 ° from each other, and the local signal having the leading phase is multiplied by the multiplier. 113, and the local signal whose phase is delayed is input to the multiplier 114.

Instead of this, as shown in FIG. 19, the received RF signal input to the received signal
In the phase shifter 211 (90 °), the received RF signals having a phase difference of 90 ° are distributed to two received RF signals, and the received RF signal whose phase is advanced is input to the multiplier 113, and the phase is delayed. The received RF signal is input to the multiplier 114, and the local signal input from the local signal input terminal 102 is split into two by the splitter 212 and
3, 114.

That is, in FIG.
114, one of the multipliers down-converts the received RF signal by a local signal having the same phase, and the other multiplier down-converts the received RF signal by a local signal having a phase difference of 90 °. Similar effects can be obtained.

Further, as shown in FIG.
F phase shifters 215 and 216 and the reception RF phase shifter 2 in FIG.
11, the same effect can be obtained even with a configuration in which the distributor 212 is combined.

It goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0089]

As described above, according to the present invention, each of the divided RF signals is multiplied by a local signal having a phase difference of 90 ° to each other to be converted into an IF signal. Of the two IF signals, the phase of one signal is advanced by α ゜ and the other phase is delayed by 90 ° -α ゜, and addition and subtraction synthesis are performed using these signals.

That is, by performing both addition synthesis and subtraction synthesis, even if the frequency of the RF signal is higher or lower than the frequency of the local signal, one of the synthesized outputs (IF signal) cancels the image signal. Signal.

Then, depending on whether the frequency of the desired signal included in the RF signal is higher or lower than the frequency of the local signal,
That is, the IF signal from which the image signal is canceled is selectively output according to the communication band to be used.

Therefore, according to the present invention, in the case where the RF signal in the communication band higher in frequency than the frequency of the local signal and the RF signal in the communication band in the lower frequency are selectively switched and received, any communication is performed. It is possible to provide an image rejection mixer capable of canceling an image signal and down-converting a desired signal also in a band, and a wireless device including the mixer.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a configuration of an embodiment of an image rejection mixer according to the present invention.

FIG. 2 is a vector diagram for explaining a phase of a received RF signal input to a multiplication unit 113 of the image rejection mixer shown in FIG.

FIG. 3 is a vector diagram for explaining a phase of a received RF signal input to a multiplication unit 114 of the image rejection mixer shown in FIG. 1;

FIG. 4 is a vector diagram for explaining a local signal phase input to the multiplication means 113 of the image rejection mixer shown in FIG.

FIG. 5 is a vector diagram for explaining a local signal phase input to a multiplication unit 114 of the image rejection mixer shown in FIG. 1;

FIG. 6 is a vector diagram for explaining an output phase of the multiplier 113 of the image rejection mixer shown in FIG. 1 when the frequency of a desired signal is higher than the frequency of a local signal.

FIG. 7 is a vector diagram for explaining an output phase of the multiplier 114 of the image rejection mixer shown in FIG. 1 when a frequency of a desired signal is higher than a frequency of a local signal.

FIG. 8 is a vector diagram for explaining an output phase of the multiplier 113 of the image rejection mixer shown in FIG. 1 when the frequency of the desired signal is lower than the frequency of the local signal.

9 is a vector diagram for explaining an output phase of the multiplier 114 of the image rejection mixer shown in FIG. 1 when the frequency of a desired signal is lower than the frequency of a local signal.

10 is a vector diagram for explaining the output phase of the IF phase shifter 115 of the image rejection mixer shown in FIG. 1 when the frequency of the desired signal is higher than the frequency of the local signal.

11 is a vector diagram for explaining the output phase of the IF phase shifter 116 of the image rejection mixer shown in FIG. 1 when the frequency of the desired signal is higher than the frequency of the local signal.

FIG. 12 is a vector diagram for explaining an output phase of the IF phase shifter 115 of the image rejection mixer shown in FIG. 1 when the frequency of a desired signal is lower than the frequency of a local signal.

FIG. 13 is a vector diagram for explaining the output phase of the IF phase shifter 116 of the image rejection mixer shown in FIG. 1 when the frequency of the desired signal is lower than the frequency of the local signal.

FIG. 14 is a vector diagram for explaining an output phase of the adder 117 of the image rejection mixer shown in FIG. 1 when the frequency of a desired signal is higher than the frequency of a local signal.

FIG. 15 is a vector diagram for explaining an output phase of a subtractor 118 of the image rejection mixer shown in FIG. 1 when a frequency of a desired signal is higher than a frequency of a local signal.

16 is a vector diagram for explaining the output phase of the adder 117 of the image rejection mixer shown in FIG. 1 when the frequency of the desired signal is lower than the frequency of the local signal.

17 is a vector diagram for explaining an output phase of a subtractor 118 of the image rejection mixer shown in FIG. 1 when the frequency of a desired signal is lower than the frequency of a local signal.

FIG. 18 is a circuit block diagram showing another configuration of the image rejection mixer according to the present invention.

FIG. 19 is a circuit block diagram showing another configuration of the image rejection mixer according to the present invention.

FIG. 20 is a circuit block diagram showing another configuration of the image rejection mixer according to the present invention.

FIG. 21 is a spectrum diagram for explaining a frequency relationship between a desired signal and an image signal when down-converting a desired signal using a local signal.

FIG. 22 is a circuit block diagram showing a configuration of a conventional image rejection mixer.

FIG. 23 is a vector diagram for explaining the phase of a received RF signal input to the multiplication means 313 of the conventional image rejection mixer shown in FIG.

24 is a vector diagram for explaining the phase of a received RF signal input to the multiplication means 314 of the conventional image rejection mixer shown in FIG.

FIG. 25 is a vector diagram for explaining a local signal phase input to the multiplication means 313 of the conventional image rejection mixer shown in FIG.

26 is a vector diagram for explaining a local signal phase input to the multiplication means 314 of the conventional image rejection mixer shown in FIG.

FIG. 27 is a vector diagram for explaining the output phase of the multiplier 313 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is higher than the frequency of the local signal.

FIG. 28 is a vector diagram for explaining an output phase of the multiplier 314 of the conventional image rejection mixer shown in FIG. 22 when the frequency of a desired signal is higher than the frequency of a local signal.

FIG. 29 is a vector diagram for explaining an output phase of the multiplier 313 of the conventional image rejection mixer shown in FIG. 22 when the frequency of a desired signal is lower than the frequency of a local signal.

FIG. 30 is a vector diagram for explaining an output phase of the multiplier 314 of the conventional image rejection mixer shown in FIG. 22 when the frequency of a desired signal is lower than the frequency of a local signal.

FIG. 31 is a vector diagram for explaining the output phase of the IF phase shifter 315 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is higher than the frequency of the local signal.

FIG. 32 is a vector diagram for explaining the output phase of the IF phase shifter 316 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is higher than the frequency of the local signal.

33 is a vector diagram for explaining the output phase of the IF phase shifter 315 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is lower than the frequency of the local signal.

FIG. 34 is a vector diagram for explaining the output phase of the IF phase shifter 316 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is lower than the frequency of the local signal.

FIG. 35 is a vector diagram for explaining the output phase of the adder 317 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is higher than the frequency of the local signal.

FIG. 36 is a vector diagram for explaining the output phase of the adder 317 of the conventional image rejection mixer shown in FIG. 22 when the frequency of the desired signal is lower than the frequency of the local signal.

FIG. 37 is a circuit block diagram showing a configuration of a conventional image rejection mixer.

FIG. 38 is a circuit block diagram showing a configuration of a conventional image rejection mixer.

[Explanation of symbols]

 101: Received signal input terminal 102: Local signal input terminal 103: IF output terminal 104: Switching signal input terminal 111, 212 ... Distributor 112: Local phase shifter 113, 114 ... Multiplier 115, 116, 215, 216 ... IF Phase shifter 117 Adder 118 Subtractor 119 Switcher 211 Receive RF phase shifter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Mizumoto 3-1-1 Asahigaoka, Hino-shi, Tokyo Inside the Toshiba Hino Plant Co., Ltd.

Claims (4)

[Claims] 1. An image rejection mixer for canceling an image signal serving as an interference wave when downconverting an RF signal received from a communication partner station and extracting a downconverted desired signal, comprising: RF distributing means for distributing RF signals RF1 and RF2; local phase shifting distributing means for distributing local signals to two local signals Lo1 and Lo2 having a phase difference of 90 ° with each other; the RF signal RF1; Lo
A first multiplying means for multiplying by 1; a second multiplying means for multiplying the RF signal RF2 by the local signal Lo2; and a second advancing the phase of the multiplication result of the first multiplying means by α 手段. 1 phase shifting means, second phase shifting means for delaying the phase of the multiplication result of the second multiplication means by 90 ° -α ゜, phase shifting result of the first phase shifting means, and the second phase shifting means. Addition means for adding and synthesizing the phase shift result of the phase shift means; subtraction means for subtracting and synthesizing the phase shift result of the second phase shift means from the phase shift result of the first phase shift means; When the frequency of the desired signal included in the signal is higher than the frequency of the local signal, the addition result of the adding means is selectively output, while the frequency of the desired signal included in the RF signal is higher than the frequency of the local signal. If the value is low, the subtraction result of the subtraction means is selectively output. An image rejection mixer comprising signal switching means. 2. An image rejection mixer for canceling an image signal which becomes an interference wave when down-converting an RF signal received from a communication partner station and extracting a down-converted desired signal, wherein the RF signals are separated by 90 RF phase shift distribution means for distributing two RF signals RF1 and RF2 having a phase difference of ゜, local distribution means for distributing a local signal to two local signals Lo1 and Lo2, the RF signal RF1, and the local signal First multiplying means for multiplying by Lo1, second multiplying means for multiplying the RF signal RF2 by the local signal Lo2, and a second multiplying means for advancing the phase of the multiplication result of the first multiplying means by α ゜. 1 phase shifting means, second phase shifting means for delaying the phase of the multiplication result of the second multiplying means by 90 ° -α °, and the first phase shifting means. Adding means for adding and synthesizing a phase shift result of the second phase shifting means and a phase shifting result of the second phase shifting means; and a phase shift of the second phase shifting means based on a phase shift result of the first phase shifting means. Subtraction means for subtracting and combining the result; and when the frequency of the desired signal included in the RF signal is higher than the frequency of the local signal, the addition result of the addition means is selectively output, while the addition result is included in the RF signal. An image rejection mixer, comprising: a signal switching unit for selecting and outputting a subtraction result of the subtraction unit when the frequency of the desired signal is lower than the frequency of the local signal. 3. A wireless device comprising a mixer for canceling an image signal that becomes an interference wave when down-converting an RF signal received from a communication partner station and extracting a down-converted desired signal, wherein the RF signal comprises: RF distributing means for distributing the two RF signals RF1 and RF2, local phase shifting distributing means for distributing the local signal to two local signals Lo1 and Lo2 having a phase difference of 90 ° from each other, and the RF signal RF1; Local signal Lo
A first multiplying means for multiplying by 1; a second multiplying means for multiplying the RF signal RF2 by the local signal Lo2; and a second advancing the phase of the multiplication result of the first multiplying means by α 手段. 1 phase shifting means, second phase shifting means for delaying the phase of the multiplication result of the second multiplication means by 90 ° -α ゜, phase shifting result of the first phase shifting means, and the second phase shifting means. Addition means for adding and synthesizing the phase shift result of the phase shift means; subtraction means for subtracting and synthesizing the phase shift result of the second phase shift means from the phase shift result of the first phase shift means; When the frequency of the desired signal included in the signal is higher than the frequency of the local signal, the addition result of the adding means is selectively output, while the frequency of the desired signal included in the RF signal is higher than the frequency of the local signal. If the value is low, the subtraction result of the subtraction means is selectively output. A wireless device comprising signal switching means. 4. A radio equipped with a mixer for canceling an image signal serving as an interference wave when down-converting an RF signal received from a communication partner station and extracting a down-converted desired signal, wherein the RF signal comprises: An RF phase shift distribution means for distributing two RF signals RF1 and RF2 having a phase difference of 90 ° to each other; a local distribution means for distributing a local signal to two local signals Lo1 and Lo2; and the RF signal RF1; First multiplication means for multiplying the local signal Lo1, second multiplication means for multiplying the RF signal RF2 and the local signal Lo2, and a phase of the multiplication result of the first multiplication means being α ゜ advanced. First phase shifting means for shifting the phase of the multiplication result of the second multiplying means by 90 ° -α ゜; and Adding means for adding and combining the phase result and the phase shift result of the second phase shifting means; and subtracting the phase shift result of the second phase shifting means from the phase shifting result of the first phase shifting means. Subtracting means for combining; and when the frequency of the desired signal included in the RF signal is higher than the frequency of the local signal, the addition result of the adding means is selectively output, while the desired signal included in the RF signal is output. A signal switching unit for selectively outputting the subtraction result of the subtraction unit when the frequency is lower than the frequency of the local signal.