Modulator

Abstract

This modulator comprises: an energy distribution unit that distributes a signal wave to be transmitted at a predetermined ratio according to a desired level for each sideband component; an even-term sideband generation unit that generates one or more signals having an even-numbered sideband component on the basis of a carrier signal and a signal wave distributed at a predetermined ratio by the energy distribution unit; and an odd-term sideband generation unit that generates one or more signals having an odd-numbered sideband wave component on the basis of the carrier signal and the signal wave distributed at the predetermined ratio by the energy distribution unit.　

Description

Modulator

[0001] The present invention relates to a modulator.

[0002] Conventionally, an Armstrong modulator has been used as a modulator. The Armstrong modulator has a simple configuration and displaces the phase or frequency of a carrier wave. That is, the Armstrong modulator performs phase modulation or frequency modulation. FIG. 6 is a diagram showing an example of the configuration of a modulator 90 of the prior art. The modulator 90 is an example of an Armstrong modulator configured as a phase modulator, and a phase adjustment unit is arranged at the input section of the signal wave.

[0003] The modulator 90 includes a carrier signal generating unit 91, a dividing unit 92, a phase adjusting unit 93, a phase adjusting unit 94, a multiplier 95, and a combiner 96. The carrier signal generating unit 91 outputs a carrier signal. The divider 92 divides the carrier signal output by the carrier signal generating unit 91 into two. One of the divided carrier signals is input to the phase adjusting unit 93. The phase adjusting unit 93 performs a phase rotation of 90 degrees on the input carrier signal and then outputs the phase rotation to the multiplier 95. Here, the phase adjusting unit 93 may be configured to be disposed between the dividing unit 92 and the multiplier 95 as shown in FIG. 6 , or may be disposed between the dividing unit 92, which is the output of the other dividing unit 92, and the combiner 96. When the phase adjusting unit 93 is disposed between the dividing unit 92 and the combiner 96, the phase rotation in the phase adjusting unit 93 is minus 90 degrees. The phase adjustment unit 94 rotates the phase of the input carrier signal by 90 degrees and then outputs the result to the multiplication unit 95. The multiplication unit 95 multiplies the phase-rotated carrier signal by the phase-rotated signal wave, and outputs the multiplied signal to the combination unit 96. The combination unit 96 outputs a signal obtained by combining the signal output from the multiplication unit 95 with the other carrier signal distributed by the distribution unit 92.

[0004] Toshiaki Shimoba and four others, "Study on a wideband RF signal transmission system using an FM batch conversion method with all-channel phase modulation," 2021 Institute of Electronics, Information and Communication Engineers General Conference

[0005] In a conventional modulator 90, the output signal from a carrier signal generator 91 is split into two, one of which is phase-rotated by 90 degrees using a phase shifter (phase adjustment unit 93), and then this signal is multiplied by a signal wave in a multiplier (multiplication unit 95).The signal multiplied by the multiplier 95 is then added to the other split output signal to obtain a pseudo carrier signal and a first sideband signal.With this configuration, it is not possible to obtain second or subsequent sideband components.

[0006] An ideal phase modulation signal waveform has first and subsequent sidewave components (second, third, fourth, etc., in FIG. 7 ), as shown in FIG. 7 . In other words, the absence of a sidewave indicates a deterioration in the distortion characteristics of the signal. Thus, conventional Armstrong modulators have had the problem of degraded distortion characteristics.

[0007] In view of the above circumstances, an object of the present invention is to provide a technique capable of suppressing deterioration of distortion characteristics of a modulated output signal.

[0008] One aspect of the present invention is a modulator comprising: an energy distribution unit that distributes a signal wave to be transmitted at a predetermined ratio according to a desired level for each sideband component; an even-term sideband generation unit that generates one or more signals having even-numbered sideband components based on a carrier signal and the signal wave distributed at the predetermined ratio by the energy distribution unit; and an odd-term sideband generation unit that generates one or more signals having odd-numbered sideband components based on the carrier signal and the signal wave distributed at the predetermined ratio by the energy distribution unit.

[0009] According to the present invention, it is possible to suppress deterioration of the distortion characteristics of the modulated output signal.

[0010] FIG. 1 is a configuration diagram of a modulator. FIG. 1 is a configuration diagram of a modulator in an embodiment. FIG. 2 is a diagram for explaining an ideal PM signal waveform according to a value of modulation index β in an embodiment. FIG. 3 is a diagram showing an example of a power table held by an information output unit in an embodiment. FIG. 4 is a diagram for explaining the mechanism of an energy distribution unit in an embodiment. FIG. 5 is a diagram showing an example of the configuration of a modulator of the prior art. FIG. 6 is a diagram showing an example of an ideal signal waveform of a phase modulation method.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] (Configuration of the embodiment) Before describing a specific configuration of the present invention, one configuration assumed to solve the problems of the present invention will be described. Fig. 1 is a configuration diagram of a modulator 10. The modulator 10 includes a carrier signal generating unit 101, a dividing unit 102, a phase adjusting unit 103, a dividing unit 104, a level adjusting unit 105, a dividing unit 106, a dividing unit 107, a phase adjusting unit 108, a dividing unit 109, a dividing unit 110, a dividing unit 111, an odd-term sideband generating unit 112, an even-term sideband generating unit 113, and a multiplexing unit 114.

[0013] The carrier signal generating unit 101 outputs a carrier signal. The dividing unit 102 inputs the carrier signal output by the carrier signal generating unit 101. The dividing unit 102 divides the input carrier signal. For example, the dividing unit 102 divides the input carrier signal into two. In this case, the dividing unit 102 divides the carrier signal into a first path and a second path. The phase adjusting unit 103 is connected to the first path divided by the dividing unit 102, and the dividing unit 104 is connected to the second path divided by the dividing unit 102. The carrier signal divided by the dividing unit 102 is input to the phase adjusting unit 103 and the dividing unit 104.

[0014] The distribution unit 104 receives the carrier signal distributed by the distribution unit 102. The distribution unit 104 distributes the received carrier signal. For example, the distribution unit 104 distributes the received carrier signal into two paths. In this case, the distribution unit 104 distributes the carrier signal to a first path and a second path. The level adjustment unit 105 is connected to the first path distributed by the distribution unit 104, and the distribution unit 110 is connected to the second path distributed by the distribution unit 104. The carrier signal distributed by the distribution unit 104 is input to the level adjustment unit 105 and the distribution unit 110.

[0015] The level adjustment unit 105 adjusts the level of the input carrier signal and outputs the level-adjusted carrier signal to the multiplexer 114. The level adjustment unit 105 is realized by, for example, a power amplifier or an attenuator.

[0016] The phase adjustment unit 103 receives the carrier signal distributed by the distribution unit 102. The phase adjustment unit 103 adjusts the phase of the input carrier signal. For example, the phase adjustment unit 103 rotates the phase of the input carrier signal by 90 degrees. The carrier signal whose phase has been adjusted by the phase adjustment unit 103 is input to the distribution unit 106.

[0017] Here, the phase adjustment unit 103 uses a phase shifter to rotate the phase of the input signal by 90 degrees (for example, if the carrier signal is cos, it is changed to sin), but it does not have to be a phase shifter as long as it is a device that can adjust the phase, and for example, a delay device may be used, or an implementation in which the phase is changed by 90 degrees by adjusting the wiring path length may be used. This is not limited to the phase adjustment unit 103, but is similar to the phase adjustment unit 108.

[0018] The dividing unit 106 receives the carrier signal whose phase has been adjusted by the phase adjusting unit 103. The dividing unit 106 divides the received phase-adjusted carrier signal into two or more paths. The carrier signals divided by the dividing unit 106 are input to the odd-term sideband generating unit 112.

[0019] The dividing unit 107 inputs a signal wave. The signal wave is a signal to be transmitted. The dividing unit 107 divides the input signal wave. For example, the dividing unit 107 divides the input signal wave into two. In this case, the dividing unit 107 divides the signal wave into a first path and a second path. A phase adjustment unit 108 is connected to the first path divided by the dividing unit 107, and a dividing unit 109 is connected to the second path divided by the dividing unit 107. The signal wave divided by the dividing unit 107 is input to the phase adjustment unit 108 and the dividing unit 109.

[0020] The phase adjustment unit 108 receives the signal wave distributed by the distribution unit 107. The phase adjustment unit 108 adjusts the phase of the input signal wave. For example, the phase adjustment unit 108 rotates the phase of the input signal wave by 90 degrees. The signal wave whose phase has been adjusted by the phase adjustment unit 108 is input to the distribution unit 111.

[0021] The dividing unit 111 receives the signal wave whose phase has been adjusted by the phase adjusting unit 108. The dividing unit 111 divides the input signal wave into two or more paths. The signal wave divided by the dividing unit 111 is input to the odd-term sideband generating unit 112.

[0022] The odd-term sidewave generating unit 112 generates odd-term sidewaves. The odd-term sidewaves are odd-numbered upper and lower sidewaves, such as the first upper sidewave (+J1), the first lower sidewave (-J1), the third upper sidewave (+J3), the third lower sidewave (-J3), .... The odd-term sidewave generating unit 112 is composed of one or more multipliers 120, one or more multiplier units 121, and one or more level adjuster units 122.

[0023] For example, if the odd-term sidewave generating unit 112 is to generate odd-numbered sidewaves up to the third sidewave (for example, the first and third sidewaves), the odd-term sidewave generating unit 112 is provided with two multipliers 120, two multipliers 121, and two level adjusters 122. Note that the multiplier 120-1 (multiplier (1x) in FIG. 1 ), which multiplies the frequency of a signal wave and outputs it, does not have to be provided because it is configured to output the input signal without any processing. In this case, the odd-term sidewave generating unit 112 is provided with one multiplier 120, and two multipliers 121 and two level adjusters 122.

[0024] Multiplier 120 converts each of the signal waves distributed by distributor 111 to a different odd multiple (n times) of frequency and outputs the converted signal waves. For example, if three multipliers 120 (N=3) are provided, multiplier 120-1 converts the signal waves distributed by distributor 111 to a frequency of 1 and outputs the converted signal waves, multiplier 120-2 converts the signal waves distributed by distributor 111 to a frequency of 3 and outputs the converted signal waves, and multiplier 120-3 converts the signal waves distributed by distributor 111 to a frequency of 5 and outputs the converted signal waves. Here, n is an odd number greater than or equal to 1.

[0025] The multiplier 121 multiplies the signal wave with n times the frequency output from the multiplier 120 by the carrier signal distributed by the distributor 106. The multiplier 121 outputs the signal obtained by the multiplication to the level adjuster 122.

[0026] The level adjustment unit 122 adjusts the level of the input signal. The level adjustment unit 122 outputs the level-adjusted signal to the multiplexing unit 114. The level adjustment unit 122 is realized by, for example, a power amplifier or an attenuator. The level adjustment unit 122 is one aspect of a second level adjustment unit.

[0027] The dividing unit 109 receives the signal wave divided by the dividing unit 107. The dividing unit 109 divides the received signal wave into two or more paths. The signal wave divided by the dividing unit 109 is input to the even-term sideband generating unit 113.

[0028] The dividing unit 110 receives the carrier signal divided by the dividing unit 104. The dividing unit 110 divides the received carrier signal into two or more paths. The carrier signal divided by the dividing unit 110 is input to the even-term sideband generating unit 113.

[0029] The even-term sidewave generating unit 113 generates even-term sidewaves. The even-term sidewaves are even-numbered upper and lower sidewaves, such as the second upper sidewave (+J2), the second lower sidewave (-J2), the fourth upper sidewave (+J4), the fourth lower sidewave (-J4), .... The even-term sidewave generating unit 113 is composed of one or more multipliers 130, one or more multiplier units 131, and one or more level adjuster units 132.

[0030] For example, if the even-term sideband generating unit 113 is to generate even-numbered sidebands up to the fourth sideband (e.g., the second sideband and the fourth sideband), the even-term sideband generating unit 113 includes two multipliers 130, two multipliers 131, and two level adjusters 132.

[0031] Multiplier 130 converts each of the signal waves distributed by distributor 109 into a different even multiple (m times) of the frequency and outputs the converted signal waves. For example, if three multipliers 130 are provided, multiplier 130-1 converts the signal waves distributed by distributor 109 into signals with double the frequency and outputs them, multiplier 130-2 converts the signal waves distributed by distributor 109 into signals with quadruple the frequency and outputs them, and multiplier 130-3 converts the signal waves distributed by distributor 109 into signals with six times the frequency and outputs them, where m is an even number greater than or equal to 2.

[0032] The multiplier 131 multiplies the signal wave with m times the frequency output from the multiplier 130 by the carrier signal distributed by the distributor 110. The multiplier 131 outputs the signal obtained by the multiplication to the level adjuster 132.

[0033] The level adjustment unit 132 adjusts the level of the input signal and outputs the level-adjusted signal to the multiplexing unit 114. The level adjustment unit 132 is realized by, for example, a power amplifier or an attenuator.

[0034] The multiplexer 114 multiplexes the signal output from the level adjuster 105 , the signals output from the odd-term sideband generator 112 , and the signals output from the even-term sideband generator 113 .

[0035] The spectrum of a phase-modulated waveform (PM waveform) (such as the waveform shown in FIG. 7 ) is uniquely determined once parameters such as the modulation index are determined, and the amplitude of each sideband is also uniquely determined. Therefore, as an example of a level adjustment method in each of the level adjustment units 105, 122, and 132 in the above-described embodiment, each of the level adjustment units 105, 122, and 132 performs level adjustment so that the amplitude component of each sideband has the same value as this ideal amplitude component.

[0036] (Operation of Modulator) With the above configuration, the modulator 10 operates as follows. In explaining the operation of the modulator 10, it is assumed that the carrier signal generated by the carrier signal generating unit 101 is f ｃ =A ｃ cos(ω ｃ t), and the signal wave is f ｓ = cos(ω ｓ t).

[0037] The carrier signal generating section 101 of the modulator 10 generates a carrier signal f ｃ =A ｃ cos(ω ｃ t) is output from the carrier signal generating unit 101. ｃ =A ｃ cos(ω ｃt) is divided by the dividing unit 102 and input to the phase adjusting unit 103 and dividing unit 104. The carrier signal f ｃ =A ｃ cos(ω ｃ t) is distributed by the distribution unit 104 and input to the level adjustment unit 105 and distribution unit 110.

[0038] The level adjustment unit 105 adjusts the input carrier signal f ｃ =A ｃ cos(ω ｃ t) and outputs it. For the sake of simplicity, the output of the level adjustment unit 105 may be expressed as [A]. That is, [A] = signal K ０ cos(ω ｃ t). Note that K ０ represents the amplitude after adjustment. ０ cos(ω ｃ t) corresponds to the carrier wave (J0).

[0039] The phase adjustment unit 103 adjusts the phase of the input carrier signal f ｃ =A ｃ cos(ω ｃ t) by rotating the phase of the carrier signal f ｃ =-A ｃ sin(ω ｃ t) by the phase adjustment unit 103. ｃ =-A ｃ sin(ω ｃ t) is distributed by the distributor 106 and input to each multiplier 121 of the odd-term sideband generating unit 112. For example, if the odd-term sideband generating unit 112 includes three multipliers 121, the distributor 106 divides the carrier signal f ｃ =-A ｃ sin(ω ｃ t) to three paths leading to the three multipliers 121. As a result, each multiplier 121 receives a carrier signal f ｃ =-A ｃ sin(ω ｃ t) is input.

[0040] The carrier signal f input to the distribution unit 110 ｃ =Aｃ cos(ω ｃ t) is distributed by the distributor 110 and input to each multiplier 131 of the even-term sideband generating unit 113. For example, if the even-term sideband generating unit 113 includes three multipliers 131, the distributor 110 divides the carrier signal f ｃ =A ｃ cos(ω ｃ t) to three paths leading to the three multipliers 131. As a result, each multiplier 131 receives a carrier signal f ｃ =A ｃ cos(ω ｃ t) is input.

[0041] The signal wave f input to the modulator 10 ｓ = cos(ω ｓ t) is divided by the dividing unit 107 and input to the phase adjusting unit 108 and the dividing unit 109. The phase adjusting unit 108 divides the input signal wave f ｓ = cos(ω ｓ t) by rotating the phase of the signal wave f ｓ = -sin(ω ｓ t) is converted into a signal wave f ｓ = -sin(ω ｓ t) is divided by the dividing unit 111 and input to each multiplier 120 of the odd-term sideband generating unit 112. For example, if the odd-term sideband generating unit 112 includes three multipliers 120, the dividing unit 111 divides the signal wave f ｓ = -sin(ω ｓ t) to three paths leading to the three multipliers 120. As a result, each multiplier 120 receives a signal wave f ｓ = -sin(ω ｓ t) is input.

[0042] Each multiplier 120 multiplies the input signal wave f ｓ = -sin(ω ｓ t) to a frequency that is a different odd multiple and outputs the frequency to the subsequent multiplier 121. For example, the multiplier 120-1 multiplies the input signal wave f ｓ = -sin(ω ｓ t) is multiplied by 1 to produce a signal wave f ｓ = -sin(ω ｓFor example, the multiplier 120-N multiplies the input signal wave f ｓ = -sin(ω ｓ t) is multiplied by n to produce a signal wave f ｓ = -sin(nω ｓ t) to the subsequent multiplication unit 121-N.

[0043] The multiplication units 121-1 to 121-N multiply the carrier signal f distributed by the distribution unit 106. ｃ =-A ｃ sin(ω ｃ t), the signal wave f output from the multipliers 120-1 to 120-N ｓ = -sin(ω ｓ t) ~ -sin(nω ｓ t), where N is an integer equal to or greater than 1. For example, the multiplier 121-1 multiplies the carrier signal f ｃ =-A ｃ sin(ω ｃ t), the signal wave f output from the multiplier 120-1 ｓ = -sin(ω ｓ The multiplication unit 121-1 multiplies the signal A obtained by the multiplication. ｃ sin(ω ｃ t) sin(ω ｓ t) to the level adjustment unit 122-1. ｃ sin(ω ｃ t) sin(ω ｓ t) can be transformed into the following equation (1) based on the product-sum formula: cos(ω ｃ +ω ｓ )t corresponds to the first upper side wave (+J1), and -cos(ω ｃ -ω ｓ )t corresponds to the first lower side wave (-J1).

[0044]

[0045] Similarly, the multiplication unit 121-N multiplies the carrier signal f distributed by the distribution unit 106 by ｃ =-A ｃ sin(ω ｃ t), the signal wave f output from the multiplier 120-Nｓ = -sin(nω ｓ The multiplication unit 121-N multiplies the signal A obtained by the multiplication. ｃ sin(ω ｃ t) sin(nω ｓ t) to the level adjustment unit 122-N. ｃ sin(ω ｃ t) sin(nω ｓ t) can be converted into the following equation (2) based on the product-sum formula: cos(ω ｃ +nω ｓ )t corresponds to the nth upper side wave (+Jn), and -cos(ω ｃ -nω ｓ )t corresponds to the nth lower side wave (-Jn).

[0046]

[0047] Level adjustment units 122-1 to 122-N adjust the amplitude levels of the signals output from multiplication units 121-1 to 121-N and output the adjusted levels. For example, level adjustment unit 122-1 adjusts the amplitude level of the signal output from multiplication unit 121-1 and outputs the adjusted levels. For the sake of simplicity in the description of this configuration, the output of level adjustment unit 122-1 is expressed as [C １ ] may also be expressed as [C １ ] is expressed as the following formula (3). １ represents the amplitude after adjustment.

[0048]

[0049] Similarly, the level adjustment unit 122-N adjusts the amplitude level of the signal output from the multiplication unit 121-N and outputs the adjusted signal. For the sake of simplicity, in this configuration, the output of the level adjustment unit 122-N is expressed as [C ｎ ] may also be expressed as [C ｎ ] is expressed as the following formula (4). ｎ represents the amplitude after adjustment.

[0050]

[0051] Moreover, the signal wave f input to the distribution unit 109 ｓ = cos(ωｓ t) is distributed by the distributor 109 and input to each multiplier 130 of the even-term sideband generating unit 113. For example, if the even-term sideband generating unit 113 includes three multipliers 130, the distributor 109 divides the signal wave f ｓ = cos(ω ｓ t) to three paths leading to the three multipliers 130. As a result, each multiplier 130 receives a signal wave f ｓ = cos(ω ｓ t) is input.

[0052] Each multiplier 130 multiplies the input signal wave f ｓ = cos(ω ｓ t) is multiplied by an even number and output to the subsequent multiplier 131. For example, the multiplier 130-1 multiplies the input signal wave f ｓ = cos(ω ｓ t) to double the frequency of the signal wave f ｓ = cos(2ω ｓ The multiplier 130-M outputs the input signal wave f ｓ = cos(ω ｓ t) is multiplied by m to produce a signal wave f ｓ = cos(mω ｓ t) to the subsequent multiplication unit 131-M, where M is an integer of 1 or greater.

[0053] The multiplication units 131-1 to 131-M multiply the carrier signal f distributed by the distribution unit 110. ｃ =A ｃ cos(ω ｃ t), the signal wave f output from the multipliers 130-1 to 130-M ｓ = cos(2ω ｓ t) ~ cos(mω ｓ For example, the multiplier 131-1 multiplies the carrier signal f ｃ =A ｃ cos(ω ｃ t), the signal wave f output from the multiplier 130-1 ｓ = cos(2ω ｓ The multiplication unit 131-1 multiplies the signal A obtained by the multiplication. ｃ cos(ω ｃt) cos(2ω ｓ t) to the level adjustment unit 132-1. ｃ cos(ω ｃ t) cos(2ω ｓ t) can be transformed into the following equation (5) based on the product-sum formula: cos(ω ｃ +2ω ｓ )t corresponds to the second upper side wave (+J2), and cos(ω ｃ -2ω ｓ )t corresponds to the second lower side wave (-J2).

[0054]

[0055] Similarly, the multiplication unit 131-M multiplies the carrier signal f ｃ =A ｃ cos(ω ｃ t), the signal wave f output from the multiplier 130-M ｓ = cos(mω ｓ The multiplication unit 131-M multiplies the signal A obtained by the multiplication. ｃ cos(ω ｃ t) cos(mω ｓ t) to the level adjustment unit 132-M. ｃ cos(ω ｃ t) cos(mω ｓ t) can be transformed into the following equation (6) based on the product-sum formula: cos(ω ｃ +mω ｓ ) t corresponds to the m-th upper side wave (+Jm), and cos(ω ｃ -mω ｓ )t corresponds to the mth lower side wave (-Jm).

[0056]

[0057] The level adjustment units 132-1 to 132-M adjust the amplitude levels of the signals output from the multiplication units 131-1 to 131-M and output the adjusted levels. For example, the level adjustment unit 132-1 adjusts the amplitude level of the signal output from the multiplication unit 131-1 and outputs the adjusted levels. For the sake of simplicity in the explanation of this configuration, the output of the level adjustment unit 132-1 is expressed as [B ２] may also be expressed as [B ２ ] is expressed as the following formula (7). ２ represents the amplitude after adjustment.

[0058]

[0059] Similarly, the level adjustment unit 132-M adjusts the amplitude level of the signal output from the multiplication unit 131-M and outputs the adjusted signal. For the sake of simplicity, in this configuration, the output of the level adjustment unit 132-M is expressed as [B ｍ ] may also be expressed as [B ｍ ] is expressed as the following formula (8). ｍ represents the amplitude after adjustment.

[0060]

[0061] The modulator 10 converts [A] and [B] obtained by the above processing. ２ ]~[B ｍ ] and [C １ ]~[C ｎ ] are combined by the combining unit 114 to generate a PM signal. That is, the PM signal generated by the modulator 10 is expressed by the following equation (9). Note that the amplitude of each sideband of the PM signal is uniquely determined according to the set modulation index.

[0062]

[0063] The modulator 10 configured as described above can suppress degradation of distortion characteristics. Specifically, the reason the modulator 10 has lower distortion than the conventional system is that, when comparing the frequency spectra of the output signal, the modulator 10 is closer to the ideal frequency spectrum than the conventional system. That is, the modulator 10 can generate more sideband signal waveforms than the conventional system and the Armstrong system. While the Armstrong system has a simple configuration and can be made compact and inexpensive, it can only generate sidebands within the range shown in the box in FIG. 7 (J0, ±J1). Therefore, the Armstrong system differs from the ideal PM signal waveform, which leads to degradation of distortion characteristics and CNR characteristics. In contrast, the modulator 10 not only has the Armstrong system's features of a simple configuration, compactness, and low cost, but can also generate any number of sidebands (J0, ±J1, ±J2, ...). This makes it possible to suppress degradation of distortion characteristics, a problem with the conventional Armstrong system. Furthermore, the CNR characteristics can be improved, which makes it possible to extend the transmission distance and increase the number of modulation levels.

[0064] (Problems with Modulator 10) The modulator 10 shown in FIG. 1 divides the energy of the signal wave input to the modulator 10 equally into each sidewave (J0, ±J1, ±J2, ...) using a divider (e.g., dividers 107, 109, and 111). That is, in the modulator 10, regardless of the sidewave to be generated, the equally divided energy of the signal wave is input to the odd-term sidewave generating unit 112 and the even-term sidewave generating unit 113. As a result, the level adjusting units 122-1 to 122-N and 132-1 to 132-M in the subsequent stages amplify sidewaves with smaller amplitudes than the desired PM spectrum, which can also amplify thermal noise and the like, potentially degrading signal quality. As such, there is room for improvement in the modulator 10 shown in FIG. 1.

[0065] Therefore, in the present invention, a configuration will be described in which the amount of energy distribution of the signal wave is devised to eliminate the need for level adjustment units 122-1 to 122-N and level adjustment units 132-1 to 132-M provided in modulator 10, and the SNR of the generated PM waveform is further improved. This will be described in detail below.

[0066] 2 is a configuration diagram of a modulator 10a according to an embodiment. The modulator 10a includes a carrier signal generating unit 101, a dividing unit 102, a phase adjusting unit 103, a dividing unit 104, a level adjusting unit 105, a dividing unit 106, a dividing unit 110, an odd-term sideband generating unit 112a, an even-term sideband generating unit 113a, a multiplexing unit 114, an information output unit 150, an energy dividing unit 151, N phase adjusting units 152, M phase adjusting units 153, and a phase adjusting unit 154.

[0067] 2, the modulator 10a includes an energy divider 151 before the input signal wave is input to the odd-term sideband generating unit 112a and the even-term sideband generating unit 113a. The modulator 10a uses the energy divider 151 to adjust the amount of signal wave energy to be appropriately divided according to the magnitude of each sideband, rather than dividing the energy equally. The magnitude of each sideband of the PM signal (= energy distribution on the frequency axis) differs depending on the modulation index β during PM modulation.

[0068] The information output unit 150 receives information on the modulation index β during PM modulation. The information output unit 150 notifies the energy distribution unit 151 of power information (amplitude information) according to the input modulation index β. Here, the power information includes power information for each sideband and information on the total value of the power of all sidebands. The information output unit 150 holds a power table in which power information according to the modulation index β is registered, and notifies the energy distribution unit 151 of the power information corresponding to the input modulation index β.

[0069] The energy distributor 151 receives the input signal wave and the power information output from the information output unit 150. The energy distributor 151 replicates the input signal wave for the number of output ports. The number of output ports may be any number, but there must be at least as many as the number of sidewaves to be generated. Therefore, when the odd-term sidewave generating unit 112a generates two odd-term sidewaves (e.g., first sidewave (±J1) and third sidewave (±J3)) and the even-term sidewave generating unit 113a generates two even-term sidewaves (e.g., second sidewave (±J2) and fourth sidewave (±J4)), the energy distributor 151 must have at least four output ports.

[0070] When duplicating the signal wave for the number of output ports, the energy distributor 151 distributes the energy at an energy ratio based on the power information output from the information output unit 150. For example, the energy distributor 151 allocates a large amount of energy to a sidewave having a large amplitude (or power obtained by squaring the amplitude), and allocates a small amount of energy to a sidewave having a small amplitude. That is, the energy distributor 151 increases the ratio so that a large amount of energy is allocated to a sidewave component having a large amplitude (or power obtained by squaring the amplitude) of each sidewave component, and decreases the ratio so that a small amount of energy is allocated to a sidewave component having a small amplitude (or power obtained by squaring the amplitude).

[0071] The phase adjustment units 152-1 to 152-N are arranged between the energy distribution unit 151 and the odd-term sideband generation unit 112a. The phase adjustment units 152-1 to 152-N receive the signal waves whose energies have been adjusted by the energy distribution unit 151. The phase adjustment units 152-1 to 152-N adjust the phases of the input signal waves whose energies have been adjusted. For example, the phase adjustment units 152-1 to 152-N rotate the phases of the input signal waves whose energies have been adjusted by 270 degrees or −90 degrees. The signal waves whose phases have been adjusted by the phase adjustment units 152-1 to 152-N are input to the odd-term sideband generation unit 112a.

[0072] Here, phase adjustment units 152-1 to 152-N use phase shifters to rotate the phase of the input signal by 270 degrees or -90 degrees (for example, if the signal wave is cos, it is changed to sin), but any device that can adjust the phase does not have to be a phase shifter, and for example, a delay device may be used, or the wiring path length may be adjusted to change the phase by 270 degrees or -90 degrees.

[0073] The phase adjustment units 153-1 to 153-M are arranged between the energy distribution unit 151 and the even-term sideband generation unit 113a. The phase adjustment units 153-1 to 153-M input signal waves whose energies have been adjusted by the energy distribution unit 151. The phase adjustment units 153-1 to 153-M adjust the phases of the input signal waves whose energies have been adjusted. For example, the phase adjustment units 153-1 to 153-M adjust the phases of the input signal waves whose energies have been adjusted by a predetermined angle (θ ２ ,…,θ ｍ The signal waves whose phases have been adjusted by the phase adjusters 153-1 to 153-M are input to the even-term side wave generating unit 113a.

[0074] The phase adjustment unit 154 is disposed between the distribution unit 104 and the level adjustment unit 105. The phase adjustment unit 154 receives the carrier signal distributed by the distribution unit 104. The phase adjustment unit 154 adjusts the phase of the input carrier signal. For example, the phase adjustment unit 154 adjusts the phase of the input carrier signal by a predetermined angle (θ ０ The signal wave whose phase has been adjusted by the phase adjustment unit 154 is input to the level adjustment unit 105.

[0075] The odd-term sidewave generating unit 112a generates odd-term sidewaves. The odd-term sidewave generating unit 112a is composed of one or more multipliers 120 and one or more multipliers 121. As described above, the odd-term sidewave generating unit 112a included in the modulator 10a does not include a level adjusting unit 122. A signal wave whose energy and phase have been adjusted is input to each multiplier 120.

[0076] The even-term sidewave generating unit 113a generates even-term sidewaves. The even-term sidewave generating unit 113a is composed of one or more multipliers 130 and one or more multipliers 131. As described above, the even-term sidewave generating unit 113a included in the modulator 10a does not include a level adjusting unit 132. A signal wave whose energy and phase have been adjusted is input to each multiplier 130.

[0077] FIG. 3 is a diagram for explaining the waveform of an ideal PM signal according to the value of the modulation index β in the embodiment. The upper part of FIG. 3 shows the waveform of an ideal PM signal when the modulation index β=0.5, the middle part of FIG. 3 shows the waveform of an ideal PM signal when the modulation index β=1, and the lower part of FIG. 3 shows the waveform of an ideal PM signal when the modulation index β=5. Here, "+Jm" in FIG. 3 means the name of the side wave, with "+" meaning that it is at a higher frequency than the carrier wave and "-" meaning that it is at a lower frequency than the carrier wave. Furthermore, "number m" means that it is the mth side wave counting from the carrier wave. "+Jm" can also be read as "the mth upper side wave," and both are synonymous. Furthermore, when expressing the amplitude of "+Jm" in the following description, P Ｊｍ It is written as follows.

[0078] As shown in Figure 3, depending on the modulation index β, the amplitude of each sideband may oscillate rather than decrease monotonically with distance from the carrier (e.g., β = 5). When generating a PM signal for each sideband, it is desirable to distribute the energy of the signal wave according to the magnitude of each sideband. For example, if a low-energy signal wave after multiple branching is used to generate a sideband with a large amplitude, large amplification is required, resulting in degradation of signal quality.

[0079] FIG. 4 is a diagram showing an example of a power table held by the information output unit 150 in this embodiment. The power table associates input values ​​with output values. In the power table, the input values ​​are modulation index β values, and the output values ​​are power information for each sideband and total power information for all sidebands. Depending on the input modulation index β value, the information output unit 150 outputs all values ​​registered in the corresponding output value field as power information to the energy distribution unit 151. The power information for each sideband is calculated in advance for each modulation index β value based on a theoretical formula for PM signals. For example, the "total power information for all sidebands" when modulation index β=5 stores a value calculated based on Equation (10).

[0080]

[0081] The energy distribution unit 151 replicates the input value f(x) for the number of output ports. The energy (∝f ２ The ratio of (x) is not an equal division, but an energy ratio weighted using a value normalized (divided) by the "power information of each sideband" and the "total value information of the power of all sidebands" output from the information output unit 150. Note that the amount of energy of the input signal and the total amount of energy of the output signal are the same (the amount of energy is conserved between input and output).

[0082] For example, if the number of output ports of the energy distribution unit 151 is two, this means a circuit that generates sidewaves "±J1" and "±J2." If the "power information of each sidewave" output from the information output unit 150 is 5 for "±J1" and 2 for the sidewaves "±J2," and the "total value information of the power of all sidewaves" is 7 (calculated as 5 + 2), the energy distribution unit 151 outputs √(5 / 7) × f(x) to the output port for the sidewaves "±J1," and outputs √(2 / 7) × f(x) to the output port for the sidewaves "±J2."

[0083] Next, the mechanism of the energy distribution unit 151 will be described with reference to FIG. 5. FIG. 5 is a diagram for explaining the mechanism of the energy distribution unit 151 in the embodiment. The energy distribution unit 151 divides the input signal f(t) at an arbitrary energy ratio and generates a plurality of output signals (f １ (t), f２ (t), ..., f ｎ＿ｍａｘ 5, when the distribution ratio of the energy distribution unit 151 is 2:1:3, the energy distribution unit 151 distributes the energy as √(2 / 6)×f(t), √(1 / 6)×f(t), and √(3 / 6)×f(t), as shown in the output waveform.

[0084] Since the energy distribution unit 151 only divides the input signal by energy, the energy is conserved between the input and output. ２ １ (t) + f ２ ２ (t) +, ..., +f ２ ｎ＿ｍａｘ (t) = f ２ The energy distribution unit 151 can be realized by a commercially available product, for example, a product called a "splitter" that branches television lines in an apartment building or the like.

[0085] (Operation of Modulator 10a) With the above configuration, the modulator 10a operates as follows. In explaining the operation of the modulator 10a, it is assumed that the carrier signal generated by the carrier signal generating unit 101 is f ｃ =A ｃ cos(ω ｃ t), and the signal wave is f ｓ = cos(ω ｓ t).

[0086] The carrier signal generating section 101 of the modulator 10a generates a carrier signal f ｃ =A ｃ cos(ω ｃ t) is output from the carrier signal generating unit 101. ｃ =A ｃ cos(ω ｃ t) is divided by the dividing unit 102 and input to the phase adjusting unit 103 and dividing unit 104. The carrier signal f ｃ =A ｃ cos(ω ｃ t) is divided by the dividing section 104 and input to the phase adjusting section 154 and dividing section 110.

[0087] The phase adjustment unit 154 adjusts the phase of the input carrier signal f ｃ =A ｃ cos(ω ｃ t) to a predetermined angle θ ０ The level adjustment unit 105 adjusts the carrier signal f ｃ =A ｃ cos(ω ｃ t+θ ０ ) is input to the level adjustment unit 105. ｃ =A ｃ cos(ω ｃ t+θ ０ ) and outputs the adjusted amplitude level. ｃ =A ｃ cos(ω ｃ t+θ ０ ) amplitude level is expressed as √(P Ｊ０ / 2P Ａｌｌ ) and output. As a result, the output of level adjustment unit 105 is expressed as in the following equation (11). Note that equation (11) corresponds to the carrier wave (J0). For the sake of simplicity in the explanation of the configuration shown in FIG. 2, the output of level adjustment unit 105 may also be expressed as [A].

[0088]

[0089] The phase adjustment unit 103 adjusts the phase of the input carrier signal f ｃ =A ｃ cos(ω ｃ t) by rotating the phase of the carrier signal f ｃ =-A ｃ sin(ω ｃ t) by the phase adjustment unit 103. ｃ =-A ｃ sin(ω ｃ t) is distributed by the distributor 106 and input to each multiplier 121 of the odd-term sideband generating unit 112. For example, if the odd-term sideband generating unit 112 includes three multipliers 121, the distributor 106 divides the carrier signal f ｃ =-A ｃ sin(ω ｃt) to three paths leading to the three multipliers 121. As a result, each multiplier 121 receives a carrier signal f ｃ =-A ｃ sin(ω ｃ t) is input.

[0090] The carrier signal f input to the distribution unit 110 ｃ =A ｃ cos(ω ｃ t) is distributed by the distributor 110 and input to each multiplier 131 of the even-term sideband generating unit 113. For example, if the even-term sideband generating unit 113 includes three multipliers 131, the distributor 110 divides the carrier signal f ｃ =A ｃ cos(ω ｃ t) to three paths leading to the three multipliers 131. As a result, each multiplier 131 receives a carrier signal f ｃ =A ｃ cos(ω ｃ t) is input.

[0091] The signal wave f input to the modulator 10 ｓ = cos(ω ｓ t) is input to the energy distribution unit 151. The information output unit 150 refers to a power table and acquires power information corresponding to the modulation index β input from the outside. The information output unit 150 outputs the acquired power information to the energy distribution unit 151. The energy distribution unit 151 calculates the power information corresponding to the input signal wave f ｓ = cos(ω ｓ t) is weighted in accordance with the power information output from the information output section 150 and output.

[0092] For example, the energy distributor 151 divides the signal wave f ｓ = cos(ω ｓ t) is weighted based on the power information corresponding to the first sidebands (±J1) and output from the output port to which the multiplier 120-1 of the odd-term sideband generating unit 112a is connected via the phase adjusting unit 152-1. The power information corresponding to the first sidebands (±J1) is P Ｊ１ P, which is indicated by the total power information of all sidebands ＡｌｌThat is, the signal wave f output from the energy distribution unit 151 to the phase adjustment unit 152-1 is expressed as ｓ１ is expressed as the following equation (12).

[0093]

[0094] Similarly, the energy distribution unit 151 divides the signal wave f ｓ = cos(ω ｓ The power information corresponding to the n-th sideband (±Jn) is weighted based on the power information corresponding to the n-th sideband (±Jn) and output from the output port to which the multiplier 120-N of the odd-term sideband generating unit 112a is connected via the phase adjusting unit 152-N. The power information corresponding to the n-th sideband (±Jn) is expressed as P Ｊｎ P, which is indicated by the total power information of all sidebands Ａｌｌ That is, the signal wave f output from the energy distribution unit 151 to the phase adjustment unit 152-N is expressed as ｓｎ is expressed as the following equation (13).

[0095]

[0096] Similarly, the energy distribution unit 151 divides the signal wave f ｓ = cos(ω ｓ The power information corresponding to the second sidebands (±J2) is weighted based on the power information corresponding to the second sidebands (±J2) and output from the output port to which the multiplier 130-1 of the even-term sideband generating unit 113a is connected via the phase adjusting unit 153-1. The power information corresponding to the second sidebands (±J2) is P Ｊ２ P, which is indicated by the total power information of all sidebands Ａｌｌ That is, the signal wave f output by the energy distribution unit 151 to the phase adjustment unit 153-1 is expressed as ｓ２ is expressed as the following equation (14).

[0097]

[0098] Similarly, the energy distribution unit 151 divides the signal wave f ｓ = cos(ω ｓThe power information corresponding to the m-th sideband (±Jm) is weighted based on the power information corresponding to the m-th sideband (±Jm) and output from the output port to which the multiplier 130-M of the even-term sideband generating unit 113a is connected via the phase adjusting unit 153-M. The power information corresponding to the m-th sideband (±Jm) is P Ｊｍ P, which is indicated by the total power information of all sidebands Ａｌｌ That is, the signal wave f output from the energy distribution unit 151 to the phase adjustment unit 153-M is expressed as ｓｍ is expressed as the following equation (15).

[0099]

[0100] The phase adjustment unit 152-1 adjusts the phase of the input signal wave f ｓ１ The phase of the given angle θ １ (For example, θ １ = 270 degrees or -90 degrees). As a result, the signal wave f input to the phase adjustment unit 152-1 is rotated by ｓ１ is converted as shown in the following equation (16). ｓ１ is output to the multiplier 120-1 of the odd-term sideband generating section 112a.

[0101]

[0102] The phase adjustment unit 152-N adjusts the phase of the input signal wave f ｓｎ The phase of the given angle θ ｎ (For example, θ ｎ = 270 degrees or -90 degrees). As a result, the signal wave f input to the phase adjustment unit 152-N is rotated by ｓｎ is converted as shown in the following equation (17). ｓｎ is output to the multiplier 120-N of the odd-term sideband generating section 112a.

[0103]

[0104] The phase adjustment unit 153-1 adjusts the phase of the input signal wave f ｓ２ The phase of the given angle θ ２ As a result, the signal wave f input to the phase adjustment unit 153-1 is rotated by ｓ２is converted as shown in the following equation (18). ｓ２ is output to the multiplier 130-1 of the even-term sideband generating section 113a.

[0105]

[0106] The phase adjustment unit 153-M adjusts the phase of the input signal wave f ｓｍ The phase of the given angle θ ｍ As a result, the signal wave f input to the phase adjustment unit 153-M is rotated by ｓｍ is converted as shown in the following equation (19). ｓｍ is output to the multiplier 130-M of the even-term sideband generating unit 113a.

[0107]

[0108] The multiplier 120-1 of the odd-term side wave generating unit 112a multiplies the input phase-adjusted signal wave f ｓ１ The multiplier 121-1 multiplies the frequency of the carrier signal f distributed by the distributor 106 by 1 and outputs the multiplied frequency to the multiplier 121-1 at the subsequent stage. ｃ =-A ｃ sin(ω ｃ t), the signal wave f output from the multiplier 120-1 ｓ１ The multiplication unit 121-1 outputs the signal obtained by the multiplication to the multiplexing unit 114. For the sake of simplicity, in the configuration shown in FIG. 2, the output of the multiplication unit 121-1 is expressed as [C １ The signal [C １ ] can be transformed into the following formula (20) based on the product-sum formula: ｃ +ω ｓ ) t + θ １} corresponds to the first upper side wave (+J1), and {-cos(ω ｃ -ω ｓ ) t-θ １} corresponds to the first lower side wave (-J1).

[0109]

[0110] The multiplier 120-N of the odd-term side wave generating unit 112a multiplies the input phase-adjusted signal wave f ｓｎ The frequency of the signal wave f is multiplied by n by the multiplier 120-N and output to the subsequent multiplier 121-N. ｓｎ is expressed as the following equation (21).

[0111]

[0112] The multiplication unit 121-N multiplies the carrier signal f distributed by the distribution unit 106 by ｃ =-A ｃ sin(ω ｃ t), the signal wave f output from the multiplier 120-N ｓｎ The multiplication unit 121-N outputs the signal obtained by the multiplication to the multiplexing unit 114. For the sake of simplicity, in the configuration shown in FIG. 2, the output of the multiplication unit 121-N is expressed as [C ｎ The signal [C ｎ ] can be transformed into the following formula (22) based on the product-sum formula: ｃ +nω ｓ ) t + θ ｎ} corresponds to the n-th upper side wave (+Jn), and {-cos(ω ｃ -nω ｓ ) t-θ ｎ} corresponds to the n-th lower side wave (-Jn).

[0113]

[0114] The multiplier 130-1 of the even-term sideband generating unit 113a multiplies the input phase-adjusted signal wave f ｓ２ The frequency of the signal wave f is doubled by the multiplier 130-1 and output to the multiplier 131-1 at the subsequent stage. ｓ２ is expressed as the following equation (23).

[0115]

[0116] The multiplier 131-1 multiplies the carrier signal f distributed by the distributor 110. ｃ =A ｃ cos(ω ｃt), the signal wave f output from the multiplier 130-1 ｓ２ The multiplication unit 131-1 outputs the signal obtained by the multiplication to the multiplexing unit 114. For the sake of simplicity, in the configuration shown in FIG. 2, the output of the multiplication unit 131-1 is expressed as [B ２ The signal [B ２ ] can be transformed into the following formula (24) based on the product-sum formula: ｃ +2ω ｓ ) t + θ ２} corresponds to the second upper side wave (+J2), and {cos(ω ｃ -2ω ｓ ) t-θ ２} corresponds to the second lower side wave (-J2).

[0117]

[0118] The multiplier 130-M of the even-term sideband generating unit 113a multiplies the input phase-adjusted signal wave f ｓｍ The frequency of the signal wave f is multiplied by m by the multiplier 130-M and output to the subsequent multiplier 131-M. ｓｍ is expressed as the following equation (25).

[0119]

[0120] The multiplication unit 131-M multiplies the carrier signal f distributed by the distribution unit 110. ｃ =A ｃ cos(ω ｃ t), the signal wave f output from the multiplier 130-M ｓｍ The multiplication unit 131-M outputs the signal obtained by the multiplication to the multiplexing unit 114. For the sake of simplicity, in the configuration shown in FIG. 2, the output of the multiplication unit 131-M is expressed as [B ｍ The signal [B ｍ ] can be transformed into the following formula (26) based on the product-sum formula: ｃ +mω ｓ ) t + θ ｍ} corresponds to the m-th upper side wave (+Jm), and {cos(ωｃ -mω ｓ ) t-θ ｍ} corresponds to the m-th lower side wave (-Jm).

[0121]

[0122] The modulator 10a converts [A] obtained by the above processing and [B] ２ ]~[B ｍ ] and [C １ ]~[C ｎ ] are combined by the combining unit 114 to generate a PM signal. That is, the PM signal generated by the modulator 10a is expressed by the following equation (27). Here, f ＰＭ represents the desired PM waveform (both amplitude, phase, and frequency).

[0123]

[0124] The modulator 10a configured as described above includes an energy divider 151 that divides the signal wave to be transmitted at a predetermined ratio according to the desired level of each sidewave component, an even-term sidewave generating unit 113a that generates one or more signals having even-numbered sidewave components based on the carrier signal and the signal wave divided at the predetermined ratio by the energy divider 151, and an odd-term sidewave generating unit 112a that generates one or more signals having odd-numbered sidewave components based on the carrier signal and the signal wave divided at the predetermined ratio by the energy divider 151.

[0125] As a result, the modulator 10a can improve the SNR of the PM waveform more than the configuration of the modulator 10 shown in FIG. 1 . Specifically, the modulator 10a can eliminate all of the level adjustment units provided in the odd-term sideband generating unit 112 and the even-term sideband generating unit 113 of the modulator 10 shown in FIG. 1 . This simplifies the configuration. Furthermore, since the modulator 10a does not perform correction (amplification) by a level adjustment unit when generating sidebands, it can suppress signal quality degradation caused by amplification of thermal noise. Therefore, it is possible to output a PM waveform with better signal quality (SNR) than the configuration of the modulator 10 shown in FIG. 1 .

[0126] (Modification 1 of the embodiment) In the above-described embodiment, the signal wave f ｓ The case where the signal wave f ｓ In this case, a plurality of signal waves f ｓ The frequency-multiplexed signal is input to the input terminal of the distribution unit 107.

[0127] (Modification 2 of the embodiment) In the above-described embodiment, the signal wave f ｓ In the description of the embodiment and the formulas, a cosine signal is used as the input. However, the signal waves to which the present invention is applicable are not limited to cosine signals, and the present invention can also be applied to signal waves of any shape other than cosine.

[0128] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0129] The present invention can be applied to an Armstrong modulator that performs phase modulation.

[0130] 10, 10b... modulator, 101... carrier signal generating unit, 102, 104, 106, 107, 109, 110, 111... distribution unit, 103, 108... phase adjustment unit, 105, 122-1 to 122-N, 132-1 to 132-M... level adjustment unit, 112, 112a... odd-term side wave generating unit, 113, 113a... even-term side wave generating unit, 114... multiplexing unit, 120, 120-1 to 120-N, 130, 130-1 to 130-M... multiplier, 121, 121-1 to 121-N, 131, 131-1 to 131-M... multiplication unit, 150... information output unit, 151... energy distribution unit 152-1 to 152-N...phase adjustment units, 153-1 to 153-M...phase adjustment units, 154...phase adjustment unit

Claims

an energy distribution unit that distributes a signal wave to be transmitted at a predetermined ratio according to a desired level of each sideband component; an even-term sideband generating unit that generates one or more signals having even-numbered sideband components based on a carrier signal and the signal waves divided by the energy dividing unit at the predetermined ratio; an odd-term sideband generating unit that generates one or more signals having odd-numbered sideband components based on the carrier signal and the signal waves divided by the energy dividing unit at the predetermined ratio; A modulator comprising: 　 The energy distribution unit determining a predetermined ratio corresponding to a desired level for each sideband component based on a modulation index during phase modulation; 10. The modulator of claim 1. 　 an information output unit that references a power table in which power information of each sideband component according to a modulation index during the phase modulation is associated with information on a total value of the power of all sidebands, and outputs information to the energy distribution unit, The energy distribution unit is determining a distribution ratio for each sideband component based on the information output from the information output unit; 3. The modulator of claim 2. 　 The energy distribution unit is The ratio is increased so that the energy of a sideband component having a large amplitude value or a large power value of each sideband component is increased, and the ratio is decreased so that the energy of a sideband component having a small amplitude value or a small power value is decreased. A modulator according to any one of claims 1 to 3.

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