Reflection filter

A method for generating a reflection filter, comprising the steps of:

• measuring a predetermined number of step responses;
• averaging the measured step responses to generate an averaged step response of the measured step responses;
• determining a time at which a reflection in the averaged step response begins;
• replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• differentiating the required step response to generate an impulse response of the required step response;
• determining a Discrete Fourier Transform (DFT) of the impulse response of the required step response to generate a spectrum response from the required step response;
• differentiating the averaged step response to generate an impulse response of the averaged step response;
• determining a Discrete Fourier Transform (DFT) of the impulse response of the averaged step response to generate a spectrum response from the averaged step response;
• dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• performing an inverse Fourier Transform on the result of the dividing step to generate a reflection filter impulse response;
• windowing the reflection filter impulse response;
• and
• truncating the reflection filter impulse response.

A method for generating a reflection filter for use in an oscilloscope, comprising the steps of:

• acquiring a waveform having a step response by the oscilloscope;
• determining an averaged step response of the acquired waveform;
• generating a spectrum response from the averaged step response;
• determining a time at which a reflection in the averaged step response begins;
• replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• generating a spectrum response from the required step response;
• dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• and
• processing the result of the dividing step to generate a reflection filter impulse response for implementation in the oscilloscope.

A processing apparatus for generating a reflection filter, comprising:

• means for determining an averaged step response of an acquired signal;
• means for generating a spectrum response from the averaged step response;
• means for determining a time at which a reflection in the averaged step response begins;
• means for replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• means for generating a spectrum response from the required step response;
• means for dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• and
• means for processing the result from the dividing means to generate a reflection filter impulse response.

An apparatus for generating a reflection filter, comprising:

• means for measuring a predetermined number of step responses;
• means for averaging the measured step responses to generate an averaged step response of the measured step responses;
• means for determining a time at which a reflection in the averaged step response begins;
• means for replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• means for differentiating the required step response to generate an impulse response of the required step response;
• means for determining a Discrete Fourier Transform (DFT) of the impulse response of the required step response to generate a spectrum response from the required step response;
• means for differentiating the averaged step response to generate an impulse response of the averaged step response;
• means for determining a Discrete Fourier Transform (DFT) of the impulse response of the averaged step response to generate a spectrum response from the averaged step response;
• means for dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• means for performing an inverse Fourier Transform on the generated spectrum of the reflection filter to generate a reflection filter impulse response;
• means for windowing the reflection filter impulse response;
• and
• means for truncating the reflection filter impulse response.

An apparatus for generating a reflection filter, comprising:

• a processor, the processor performing the steps of:
• determining an averaged step response of an acquired signal;
• generating a spectrum response from the averaged step response;
• determining a time at which a reflection in the averaged step response begins;
• replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• generating a spectrum response from the required step response;
• dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• and
• processing the result of the dividing step to generate a reflection filter impulse response.

An oscilloscope for generating a reflection filter, comprising:

• a processor, the processor performing the steps of:
• acquiring a waveform having a step response by the oscilloscope;
• determining an averaged step response of the acquired waveform;
• generating a spectrum response from the averaged step response;
• determining a time at which a reflection in the averaged step response begins;
• replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• generating a spectrum response from the required step response;
• dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• and
• processing the result of the dividing step to generate a reflection filter impulse response for implementation in the oscilloscope.

A computer program for implementation in a processing apparatus, the computer program including instructions for:

• determining an averaged step response of an acquired signal;
• generating a spectrum response from the averaged step response;
• determining a time at which a reflection in the averaged step response begins;
• replacing information in the averaged step response after the determined time when the reflection begins with an ideal flat line response to generate a required step response;
• generating a spectrum response from the required step response;
• dividing each frequency point of the spectrum response corresponding to the required step response by each frequency point of the spectrum response corresponding to the averaged step response to generate a spectrum of the reflection filter;
• and
• processing the result of the dividing step to generate a reflection filter impulse response.