Digitizer module, a waveform generating module, a converting method, a waveform generating method, and recording medium for recording a program thereof

A digitizer module for converting a pair of analog signals into a pair of digital signals with equal sample timing, comprising:

• an AD converter for sampling said pair of analog signals at a predetermined time interval and converting into a first and a second digital signals;
• a first digital filter for generating a first converted signal into which said first digital signal is converted on the basis of a predetermined filter coefficient;
• a correcting filter coefficient generator for generating a correcting filter coefficient correcting a skew, besides a waveform of an impulse response of said correcting filter coefficient is same as said first digital filter, on the basis of said skew of a timing with which said pair of analog signals are sampled by said AD converter and a predetermined filter coefficient;
• and
• a second digital filter for converting said second digital signal on the basis of said correcting filter coefficient and generating a second converted signal on which said skew is corrected.

A waveform generating module for outputting a pair of synchronous analog signals, comprising:

• a first digital signal calculating unit for generating a first digital signal on the basis of a first signal frequency component representing a component of each frequency of a first analog signal, which said waveform generating module should output;
• a second digital signal calculating unit for generating a second digital signal on the basis of a second signal frequency component representing a component of each frequency of a second analog signal, which said waveform generating module should output;
• a DA converter for converting said first and second digital signals into said first and second analog signals at a predetermined time interval respectively;
• a skew frequency component calculating unit for calculating a skew frequency component representing a phase error of each frequency of said second analog signal corresponding to said first analog signal, on the basis of a skew of a timing with which said first and second digital signals are converted by said DA converter;
• and
• a second signal frequency component correcting unit for correcting said second signal frequency component used for generating said second digital signal by said second digital signal calculating unit on the basis of said skew frequency component.

A waveform generating module for outputting a pair of synchronous analog signals, comprising:

• a first digital filter for generating a first converted signal into which a first digital signal, which represents a signal value of a first analog signal to be outputted, is converted on the basis of a first filter coefficient;
• a second digital filter for generating a second converted signal into which a second digital signal, which represents a signal value of a second analog signal to be outputted, is converted on the basis of a second filter coefficient;
• a DA converter for converting said first and second digital signals into said first and second analog signals at a predetermined time interval respectively;
• and
• a correcting filter coefficient generator for generating said second filter coefficient correcting a skew, besides a waveform of an impulse response of said correcting filter coefficient is same as said first digital filter, on the basis of said skew of a timing with which said DA converter converts said first and second digital signals into said first and second analog signals and said first filter coefficient.

A recording medium for recording a program used for a digitizer module converting a pair of analog signals into a pair of digital signals with equal sample timing,

• wherein said digitizer module comprises an AD converter for sampling said pair of analog signals at a predetermined time interval and converting said pair of analog signals into a first and second digital signals, and
• said program allows said digitizer module to function with:
• a second signal frequency component calculating unit for calculating a second signal frequency component representing a component of each frequency of said second digital signal on the basis of said second digital signal;
• a skew frequency component calculating unit for calculating a skew frequency component representing a phase error of each frequency of said second digital signal corresponding to said first digital signal, on the basis of said skew of a timing with which said pair of analog signals are sampled by said AD converter;
• and
• a second signal frequency component correcting unit for correcting said second signal frequency component on the basis of said skew frequency component.

A converting method for converting a pair of analog signals into a pair of digital signals with equal sample timing, comprising the steps of:

• sampling said pair of analog signals at a predetermined time interval and converting said pair of analog signals into a first and second digital signals respectively;
• calculating a second signal frequency component representing a component of each frequency of said second digital signal on the basis of said second digital signal;
• calculating a skew frequency component representing a phase error of each frequency of said second digital signal corresponding to said first digital signal, on the basis of said skew of a timing with which said pair of analog signals are sampled during said step of sampling and converting;
• and
• correcting said second signal frequency component on the basis of said skew frequency component.

A recording medium for recording a program used for a digitizer module converting a pair of analog signals into a pair of digital signals with equal sample timing,

• wherein said digitizer module comprises an AD converter for sampling said pair of analog signals at a predetermined time interval and converting said pair of analog signals into a first and second digital signals, and
• said program allows said digitizer module to function with:
• a first digital filter for generating a first converted signal into which said first digital signal is converted on the basis of a predetermined filter coefficient;
• a correcting filter coefficient generator for generating a correcting filter coefficient correcting a skew, besides a waveform of an impulse response of said correcting filter coefficient is same as said first digital filter, on the basis of said skew of a timing with which said first and second analog signals are converted by said AD converter and said predetermined filter coefficient;
• and
• a second digital filter for converting said second digital signal on the basis of said correcting filter coefficient and generating a second converted signal on which said skew is corrected.

A converting method for converting a pair of analog signals into a pair of digital signals with equal sample timing, comprising the steps of:

• sampling said pair of analog signals at a predetermined time interval and converting said pair of analog signals into a first and second digital signals respectively;
• generating a first converted signal into which said first digital signal is converted on the basis of a predetermined filter coefficient;
• generating a correcting filter coefficient correcting a skew, besides a waveform of an impulse response of said correcting filter coefficient is same as said step of generating said first converted signal, on the basis of said skew of a timing with which said first and second analog signals are converted by said AD converter and said predetermined filter coefficient;
• and
• converting said second digital signal on the basis of said correcting filter coefficient and generating a second converted signal on which said skew is corrected.

A recording medium for recording a program used for a waveform generating module outputting a pair of synchronous analog signals,

• wherein said waveform generating module comprises a DA converter for converting a first and second digital signals into a first and second analog signals at a predetermined time interval respectively, and
• said program allows said waveform generating module to function with:
• a first digital signal calculating unit for generating said first digital signal on the basis of a first signal frequency component representing a component of each frequency of said first analog signal, which should be outputted by said waveform generating module;
• a second digital signal calculating unit for generating said second digital signal on the basis of a second signal frequency component representing a component of each frequency of said second analog signal, which should be outputted by said waveform generating module;
• a skew frequency component calculating unit for calculating a skew frequency component representing a phase error of each frequency of said second analog signal corresponding to said first analog signal, on the basis of said skew of a timing with which said first and second digital signals are converted by said DA converter;
• and
• a second signal frequency component correcting unit for correcting said second signal frequency component used for generating said second digital signal by said second digital signal calculating unit, on the basis of said skew frequency component.

A waveform generating method for outputting a pair of synchronous analog signals, comprising the steps of:

• generating a first digital signal on the basis of a first signal frequency component representing a component of each frequency of a first analog signal, which should be outputted;
• generating a second digital signal on the basis of a second signal frequency component representing a component of each frequency of a second analog signal, which should be outputted;
• converting said first and second digital signals into said first and second analog signals at a predetermined time interval respectively;
• calculating a skew frequency component representing a phase error of each frequency of said second analog signal corresponding to said first analog signal, on the basis of a skew of a timing with which said first and second digital signals are converted during said step of converting;
• and
• correcting said second signal frequency component used for generating said second digital signal during said step of generating said second digital signal, on the basis of said skew frequency component.

A recording medium for recording a program used for a waveform generating module outputting a pair of synchronous analog signals,

• wherein said waveform generating module comprises a DA converter for converting a first and second digital signals into a first and second analog signals at a predetermined time interval respectively, and
• said program allows said waveform generating module to function with:
• a first digital filter for generating a first converted signal into which a first digital signal, which represents a signal value of said first analog signal to be outputted, is converted on the basis of a first filter coefficient;
• a second digital filter for generating a second converted signal into which a second digital signal, which represents a signal value of said second analog signal to be outputted, is converted on the basis of a second filter coefficient;
• and
• a correcting filter coefficient generator for generating said second filter coefficient correcting a skew, besides a waveform of an impulse response of said correcting filter coefficient is same as said first digital filter, on the basis of said skew of a timing with which said first and second digital signals converted into said first and second analog signals by said DA converter and said first filter coefficient.

A waveform generating method for outputting a pair of synchronous analog signals, comprising the steps of:

• generating a first converted signal into which a first digital signal, which represents a signal value of a first analog signal to be outputted, is converted on the basis of a first filter coefficient;
• generating a second converted signal into which a second digital signal, which represents a signal value of a second analog signal to be outputted, is converted on the basis of a second filter coefficient;
• converting said first and second digital signals into said first and second analog signals at a predetermined time interval respectively;
• and
• generating said second filter coefficient correcting a skew, besides a waveform of an impulse response of said second filter coefficient is same as said first digital filter, on the basis of said skew of a timing with which said first and second digital signals converted into said first and second analog signals during said step of converting and said first filter coefficient.