JP2000049873A - Ask modulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the ASK modulated high frequency signals of a high frequency at a low cost. SOLUTION: First high frequency signals f1 are generated and branched into two by a crystal oscillator 101, a PLL 102, a VCO 103 and a frequency divider 104, one is inputted to a multiplier 105 and second high frequency signals f2 are generated. The other branched one is inputted to an ASK modulator 106 and ASK modulation is performed by modulation signals from which higher harmonic components are removed by an LPF 107. Respective outputs are inputted to an up converter 108 (or down converter) and the ASK modulated third high frequency signals f3 of the high frequency are taken out. By passing the output of the multiplier 105 or the output of the up converter 108 (or down converter) through a band-pass filter and removing unrequired signals, the ASK modulated high frequency signals of higher quality are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modulator for performing ASK (Amplitude Shift Keying) used for mobile radio communication or the like.

[0002]

2. Description of the Related Art FIG. 3 shows a configuration of a conventional ASK modulator. In FIG. 3, 1 is a crystal oscillator, and 2 is a PLL (Phas
e Locked Loop: phase locked loop), 3 is VCO (Voltag)
e Controlled Oscillator: 4 is 1 /
N frequency dividers, which generate a predetermined first high-frequency signal f1. Reference numeral 5 denotes an ASK modulator, generally a diode switch or the like is used, and a first high-frequency signal f1 from the VCO 3 is input to the ASK modulator 5. 6 is LPF (Low Pass Filter)
The input modulated signal is input to the ASK modulator 5 after removing the harmonic signal. Therefore, the first high-frequency signal f1 is ASK-modulated by the ASK modulator 3 and output, and the level is adjusted by the amplifier 7. On the other hand, a predetermined second high-frequency signal f2 is generated by the crystal oscillator 8, the PLL 9, the VCO 10, and the frequency divider 11, and the second high-frequency signal f2 and the ASK-modulated first high-frequency signal output from the amplifier 7 are output. The signal f1 is added by the up-converter 12 and ASK-modulated third high-frequency signal f3
Is obtained, and the level is adjusted by the amplifier 13 and output.

As described above, even in the above-mentioned conventional ASK modulation device, predetermined first and second high-frequency signals are generated, and the first high-frequency signal is subjected to ASK modulation by the modulation signal to generate the second high-frequency signal. By performing the addition, a third high-frequency signal subjected to ASK modulation can be extracted.

[0004]

However, the conventional ASK modulator has two circuits, one for generating the first high-frequency signal and the other for generating the second high-frequency signal. There is a problem that the scale is large, the number of parts is large, the size cannot be reduced, and the cost is high.

Therefore, as shown in FIG.
1, the PLL 22, the VCO 23, and the frequency divider 26 directly generate the third high-frequency signal f3. The third high-frequency signal is ASK-modulated by the ASK modulator 25 using the modulation signal passed through the LPF 26. A configuration to adjust the level was considered.

However, according to this configuration, since a circuit for generating the second high-frequency signal and an up converter are not required, the circuit scale is small, the number of parts is small, and the dimensions can be reduced. , If the third high-frequency signal is at a very high frequency, for example 5.8 GHz,
Another problem is that a circuit for directly generating a high-frequency signal and an ASK modulator become very expensive.

The present invention is to solve such a conventional problem, and has a small circuit scale and a small number of parts.
An object of the present invention is to provide an excellent ASK modulator that can be reduced in size and inexpensive.

[0008]

According to the present invention, in order to achieve the above object, a first high-frequency signal is generated, divided into two, input to a multiplier, and the other to an ASK modulator. Then, the respective outputs are input to an up-converter or a down-converter to extract a third high-frequency signal subjected to ASK modulation. The present invention also provides
The output of the multiplier or the output of the up-converter or the down-converter is passed through a band-pass filter to remove unnecessary signals. As a result, the circuit scale is small, the number of parts is small, and the dimensions can be reduced.
An excellent ASK modulator that can be manufactured at low cost can be realized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 of the present invention is an ASK for ASK-modulating a high-frequency signal generated by a VCO driven by a PLL with a modulation signal and outputting the modulated signal.
In a modulation device, an ASK for splitting a high-frequency signal output from the VCO into two, inputting one to a multiplier for multiplying the high-frequency signal, and the other for ASK modulation by a modulation signal
An ASK modulator that inputs the output of the multiplier and the ASK modulator to an up-converter to extract an ASK-modulated high-frequency signal, amplifies the signal by an amplifier, and adjusts the level of the high-frequency signal. ASK-modulated high-frequency signals can be easily extracted.

According to a second aspect of the present invention, a PLL
ASK modulator that ASK-modulates a high-frequency signal generated by a VCO driven by a modulation signal with a modulation signal and outputs the resulting signal, splits the high-frequency signal output from the VCO into two, and inputs one of the two to a multiplier that multiplies the high-frequency signal. And
The other is input to an ASK modulator that performs ASK modulation by a modulation signal, and the outputs of the multiplier and the ASK modulator are input to a down converter to extract an ASK-modulated high-frequency signal, which is amplified by an amplifier and adjusted in level. AS
This is a K modulator, and can easily extract a high frequency ASK modulated high frequency signal.

According to a third aspect of the present invention, there is provided the ASK modulator according to the first aspect, wherein an unnecessary signal is removed by passing an output of the multiplier through a band-pass filter, and a harmonic component generated by the multiplier is provided. And a higher quality ASK-modulated high-frequency signal can be extracted.

According to a fourth aspect of the present invention, there is provided the ASK modulator according to the second aspect, wherein an unnecessary signal is removed by passing an output of the multiplier through a band-pass filter, and a harmonic component generated by the multiplier is provided. And a higher quality ASK-modulated high-frequency signal can be extracted.

According to a fifth aspect of the present invention, there is provided the ASK modulator according to the first aspect, wherein an unnecessary signal is removed by passing an output of the up-converter through a band-pass filter. By removing the components, a higher quality ASK-modulated high-frequency signal can be extracted.

According to a sixth aspect of the present invention, there is provided the ASK modulator according to the second aspect, wherein an unnecessary signal is removed by passing an output of the down converter through a band-pass filter. By removing the components, a higher quality ASK-modulated high-frequency signal can be extracted.

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an ASK modulation device according to Embodiment 1 of the present invention.
In FIG. 1, 101 is a crystal oscillator, 102 is a PLL,
Reference numeral 103 denotes a VCO, and 104 denotes a frequency divider. These are the same general ones as in the conventional example, and can obtain a predetermined first high-frequency signal f1. Numeral 105 denotes a multiplier, which outputs one of the branched outputs of the VCO 103 to 2
The frequency is multiplied to output a second high-frequency signal f2. 106 is A
This is an SK modulator, to which the other of the branched outputs of the VCO 103 is input. Reference numeral 107 denotes an LPF, which removes harmonic components of the modulation signal and outputs the result to the ASK modulator 106. 1
Reference numeral 08 denotes an upconverter that adds the output of the multiplier 105 and the output of the ASK modulator 106 and outputs a third high-frequency signal f3. 109 is an up converter 108
Is an amplifier that adjusts the output level of the power supply.

Next, the operation of the ASK modulator configured as described above will be described. Crystal oscillator 101, PL
The first high-frequency signal f1 generated by the L102, the VCO 103, and the frequency divider 104 is branched into two from the VCO 103, one is input to the multiplier 105, and the other is the AS
The signal is input to the K modulator 106. The first high-frequency signal f1 input to the multiplier 105 is doubled by the multiplier 105 to become a second high-frequency signal f2.
08 is input. On the other hand, the first high-frequency signal f1 input to the ASK modulator 106 is ASK-modulated by the modulation signal from which the harmonic components have been removed by the LPF 107, and is input to the up-converter 108. In the up-converter 108, the input second high-frequency signal f2
And an ASK-modulated first high-frequency signal f1 to add an ASK-modulated third high-frequency signal f1
3 is generated, the level of which is adjusted by the amplifier 109 and output.

As described above, according to the first embodiment, V
Since the first high-frequency signal f1 output from the CO 103 is branched into two and one of the two is multiplied by the multiplier 105, an advantage that a high-frequency signal of a high frequency can be easily generated using a general multiplier is provided. Have. This is very advantageous when the target frequency is very high, for example at 5.8 GHz. Further, the other of the branched first high-frequency signals is input to the ASK modulator 106 and ASK-modulated, so that an ASK modulation can be applied to a relatively low-frequency high-frequency signal, and an expensive ASK modulator is used. There is an advantage that there is no need. Further, a multiplier and an AS
Since the output of the K modulator is input to the up-converter 108 and added, there is an advantage that a high-frequency ASK-modulated high-frequency signal can be easily extracted. Further, since only one circuit for generating a high-frequency signal from the crystal oscillator is used, the circuit scale is small, the number of parts is small, the size can be reduced, and the AS
This has the effect of realizing a K modulator.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described. In the second embodiment, as shown in FIG. 2, only up converter 108 in the first embodiment shown in FIG. 1 is changed to down converter 110, and other components are the same as those in FIG. Elements are assigned the same reference numerals and duplicate explanations are omitted. According to the second embodiment, the second high-frequency signal f2 output from the multiplier 105 and the second high-frequency signal f2 output from the ASK modulator 106 are output.
By subtracting the SK-modulated first frequency f1 to generate a high-frequency ASK-modulated third high-frequency signal f3, the same effect as in the first embodiment is obtained.

Third Embodiment Next, a third embodiment of the present invention will be described. In the third embodiment, a band-pass filter is inserted between the multiplier 105 and the up converter 108 or the down converter 110 in the first and second embodiments. As a result, harmonic components generated in the multiplier 105 can be removed,
A higher-quality ASK-modulated high-frequency signal can be extracted.

(Embodiment 4) Next, Embodiment 4 of the present invention will be described. In the fourth embodiment, a band-pass filter is inserted between up-converter 108 or down-converter 110 and amplifier 109 in the first and second embodiments. As a result, high frequency components generated by the up converter 108 or the down converter 110 can be removed, and a higher quality ASK modulated high frequency signal can be extracted.

[0021]

According to the present invention, as is apparent from the above embodiment, the high-frequency signal output from the VCO is divided into two, one of which is multiplied by a multiplier and the other is ASK-modulated by an ASK modulator. , By the up converter or the down converter, the following effects are obtained. (1) A high frequency signal of a high frequency can be easily generated using a general multiplier. (2) Since ASK modulation is applied to a high frequency signal having a relatively low frequency, it is not necessary to use an expensive ASK modulator. (3) Since the outputs of the multiplier and the ASK modulator are combined by the up-converter or the down-converter, a high-frequency ASK-modulated high-frequency signal can be easily extracted. (4) Since only one circuit is required to generate a high-frequency signal from the crystal oscillator, the circuit scale is small, the number of parts is small, the size can be reduced, and an inexpensive ASK modulator can be realized as a whole. (5) A high-quality ASK-modulated high-frequency signal can be extracted by inserting a band-pass filter for removing unnecessary signals after the multiplier or after the up-converter or down-converter.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an ASK modulation device according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an ASK modulation device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an ASK modulation device in a conventional example.

FIG. 4 is a block diagram showing another configuration of an ASK modulation device in a conventional example.

[Explanation of symbols]

 101 Crystal Oscillator 102 PLL 103 VCO 104 Divider 105 Multiplier 106 ASK Modulator 107 LPF 108 Up Converter 109 Amplifier 110 Down Converter

Claims (6)

[Claims] 1. An ASK modulation device for ASK-modulating a high-frequency signal generated by a VCO driven by a PLL with a modulation signal and outputting the resulting signal, the high-frequency signal output from the VCO is branched into two, and one of the two is divided by the high-frequency signal. The input is input to a multiplier for multiplication, the other is input to an ASK modulator for ASK modulation by a modulation signal, and the outputs of the multiplier and the ASK modulator are input to an up-converter to take out an ASK-modulated high-frequency signal. ASK modulator that adjusts the level by amplifying with an amplifier. 2. An ASK modulation device for ASK-modulating a high-frequency signal generated by a VCO driven by a PLL with a modulation signal and outputting the resulting signal, the high-frequency signal output from the VCO is split into two branches, and one of the two is divided by the high-frequency signal The input is input to a multiplier for multiplying, the other is input to an ASK modulator for ASK modulation by a modulation signal, and the output of the multiplier and the ASK modulator is input to a down converter to extract an ASK-modulated high-frequency signal. ASK modulator that adjusts the level by amplifying with an amplifier. 3. The ASK modulator according to claim 1, wherein an output of the multiplier is passed through a band-pass filter to remove unnecessary signals. 4. The ASK modulator according to claim 2, wherein an output of the multiplier is passed through a band-pass filter to remove unnecessary signals. 5. The AS according to claim 1, wherein an output of the up-converter is passed through a band-pass filter to remove unnecessary signals.
K modulator. 6. The AS according to claim 2, wherein an unnecessary signal is removed by passing an output of the down converter through a band-pass filter.
K modulator.