Distortion compensating apparatus

A distortion compensating device for carrying out predistortion on a power amplifying means whose distortion should be compensated, comprising:

• an envelope detecting means to which a high-frequency signal generating an envelope change is supplied for detecting an envelope signal of the high-frequency signal;
• a phase correction memory means for storing an inverted distortion phase value of a distortion generated in said power amplifying means with digital data obtained by digitalizing the envelope signal of said envelope detecting means as an address;
• and
• a phase-shifting means disposed in a prestage of said power amplifying means to which the high-frequency signal generating the envelope change is supplied, capable of controlling a passage phase of the high-frequency signal, wherein
• the inverted distortion data of said phase correction memory means is converted to analog data and supplied to said phase-shifting means so as to compensate a distortion of the phase of said power amplifying means.

A distortion compensating device for carrying out predistortion on a power amplifying means whose distortion should be compensated, comprising:

• an envelope detecting means to which a high frequency signal generating an envelope change is supplied for detecting an envelope signal of the high frequency signal;
• a phase correction memory means which stores an inverted distortion phase value of distortion to be generated in said power amplifying means with digital data obtained by digitalizing the envelope signal of said envelope detecting means as an address;
• and
• a phase-shifting means which is located at a poststage of said power amplifying means to which the high frequency signal generating the envelope change is supplied and can control passage phase of the high frequency signal, wherein
• an inverted distortion data of said phase correction memory means is converted into analog data to supply to said phase-shifting means and distortion of phase of said power amplifying means is compensated.

A distortion compensating device comprising:

• a first envelope detecting means for detecting an envelope signal with a part of a high frequency signal having fluctuation of envelope as an input;
• a digital-to-analog converting means for converting the envelope signal of said first envelope detecting means into digital data;
• an amplitude correction memory means in which digital data is inputted as an address and which outputs amplitude correction data corresponding to the address by means of data stored for amplitude correction in advance;
• a first low pass filtering means for converting the amplitude correction data into an analog signal to eliminate digital noise of the analog signal;
• a phase correction memory means in which digital data is inputted as an address and which outputs phase correction data corresponding to the address by means of data stored for phase correction in advance;
• a second low pass filtering means for converting the phase correction data into an analog signal to eliminate digital noise of the analog signal;
• a delay means which can adjust the volume of delay of passing time by means of a control signal to be added into a control terminal with the high frequency signal as an input;
• a gain variable means for varying a passage gain depending on the voltage of the signal from said first low pass filtering means, to be added into a control terminal with a delay signal of said delay means as an input;
• a phase-shifting means for varying a passage phase by an output signal from said second low pass filtering means with an output of said gain variable means as an input to input a variable output signal into a power amplifying means whose distortion should be compensated;
• a second envelope detecting means for detecting an envelope signal of the output of said power amplifying means whose distortion should be compensated;
• a subtracting means for detecting a difference between envelope signals with envelope signals of said first and second envelope detecting means as inputs;
• and
• a third low pass filtering means for detecting only a DC signal of said subtracting means, wherein
• the DC signal of said third low pass filtering means is fed back to the control terminal of said delay means.

A distortion compensating device comprising:

• a first envelope detecting means for detecting an envelope signal with a part of a high frequency signal having fluctuation of envelope as an input;
• a digital-to-analog converting means for converting the envelope signal of said first envelope detecting means into digital data;
• an amplitude correction memory means in which digital data is inputted as an address and which outputs amplitude correction data corresponding to the address by means of data stored for amplitude correction in advance;
• a first low pass filtering means for converting the amplitude correction data into an analog signal to eliminate digital noise of the analog signal;
• a phase correction memory means in which the digital data is inputted as an address and which outputs phase correction data corresponding to the address by means of data stored for phase correction in advance;
• a second low pass filtering means for converting the phase correction data into an analog signal to eliminate digital noise of the analog signal;
• a delay means which can adjust the volume of delay of passing time by means of a control signal to be added into a control terminal with the high frequency signal as an input;
• a gain variable means for varying a passage gain depending on the voltage of the signal, from said first low pass filtering means, to be added into a control terminal with a delay signal of said delay means as an input;
• a phase-shifting means for varying a passage phase by means of an output signal from said second low pass filtering means by inputting an output of said gain variable means into a power amplifying means whose distortion should be compensated and inputting an output of said power amplifying means thereinto;
• a second envelope detecting means for detecting an envelope signal of the output of said phase-shifting means;
• a subtracting means for detecting a difference between envelope signals with envelope signals of said first and second envelope detecting means as inputs;
• and
• a third low pass filtering means for detecting only a DC signal of said subtracting means, wherein
• the DC signal of said third low pass filtering means is fed back to the control terminal of said delay means.

A distortion compensating device comprising:

• a first envelope detecting means for detecting an envelope signal with a part of a high frequency signal having fluctuation of envelope as an input;
• a digital-to-analog converting means for converting the envelope signal of said first envelope detecting means into digital data;
• an amplitude correction memory means in which the digital data is inputted as an address and which outputs amplitude correction data corresponding to the address by means of data stored for amplitude correction in advance;
• a multiplying means in which digital multiplier is the product with a digital output of said amplitude correction memory means as multiplicand;
• a first low pass filtering means for converting digital data of said multiplying means to an analog signal to eliminate digital noise of the analog signal;
• a phase correction memory means in which the digital data is inputted as an address and which outputs phase correction data corresponding to the address by means of data stored for phase correction in advance;
• a second low pass filtering means for converting the phase correction data into an analog signal to eliminate digital noise of the analog signal;
• a delay means which can adjust the volume of delay of passing time by means of a control signal to be added into a control terminal with the high frequency signal as an input;
• a gain variable means for varying a passage gain depending on the voltage of the signal from said first low pass filtering means, to be added into a control terminal with a delay signal of said delay means as an input;
• a phase-shifting means for varying a passage phase by an output signal from said second low pass filtering means with an output of said gain variable means as an input to input a variable output signal into a power amplifying means whose distortion should be corrected;
• a second envelope detecting means for detecting an envelope signal of the output of said power amplifying means whose distortion should be corrected;
• a subtracting means for detecting a difference between envelope signals with envelope signals of said first and second envelope detecting means as inputs;
• a third low pass filtering means for detecting only a DC signal of said subtracting means to feed it back to the control terminal of said delay means;
• and
• a correction data memory means for outputting data, corresponded to the address, which corrects a change of characteristic due to temperature with output of digital data in which an output difference signal of said subtracting means is digitalized as an address, wherein
• data corresponding to the address from said correction data memory means is supplied as multiplier of said multiplying means.