Ultrasonic-echo envelope detection with shared finite-impulse-response (FIR)/Hilbert multiplier

An ultrasonic-echo envelope detector comprising:

• an Analog-to-Digital Converter (ADC) that receives an analog signal from an antenna, the analog signal being an ultrasonic echo waveform of an ultrasonic pulse reflected back from an external object, the ADC generating a digital input waveform having a plurality of input values for a plurality of time points;
• an analytic transformer having a reconfigurable signal operation unit that band-pass filters the digital input waveform to generate a filtered value for each of the plurality of timepoints, and that performs a Hilbert transform on a series of the filtered value to generate an inline output and a quadrature output;
• wherein the reconfigurable signal operation unit performs both a band pass filter and the Hilbert transform for each input value in the plurality of timepoints;
• reconfigurable control logic for controlling the reconfigurable signal operation unit to perform the band pass filter on the digital input waveform and to perform the Hilbert transform on a series of the filtered value to generate an inline output and a quadrature output;
• a coefficient storage for storing a plurality of filter coefficients that are applied to the reconfigurable signal operation unit when performing the band pass filter, and for storing a plurality of Hilbert coefficients that are applied to the reconfigurable signal operation unit when performing the Hilbert transform;
• wherein the coefficient storage includes a semiconductor memory;
• and
• an absolute generator that receives the inline output and the quadrature output generated by the Hilbert transform, the absolute generator calculating an absolute value of a sum of squares of the inline output and the quadrature output, the absolute generator outputting the absolute value as a detected envelope value for a current time point is a point on a detected envelope of the digital input waveform;
• wherein the detected envelope value represents an envelope enclosing peaks of the analog signal.

A reconfigurable envelope detector comprising:

• a waveform input receiving a digital waveform;
• a filter coefficient storage for storing band pass filter coefficients in a solid-state memory;
• a Hilbert filter coefficient storage for storing Hilbert filter coefficients in a solid-state memory;
• a first Finite-Impulse-Response (FIR) unit that comprises:
• a first forward tapped delay line between a first forward input and a first forward output;
• wherein the first forward input receives the digital waveform from the waveform input;
• a first reverse tapped delay line between a first reverse input and a first reverse output;
• a first tap selector that selects a first selected tap from the first forward tapped delay line or from the first reverse tapped delay line;
• a first filter coefficient selector that selects a first filter coefficient from the filter coefficient storage;
• a first multiplier that multiplies the first selected tap with the first filter coefficient to generate a first product;
• a second FIR unit that comprises:
• a second forward tapped delay line between a second forward input and a second forward output;
• a second reverse tapped delay line between a second reverse input and a second reverse output;
• wherein the second forward input receives the first forward output;
• wherein the second reverse output drives the first reverse input;
• a second tap selector that selects a second selected tap from the second forward tapped delay line or from the second reverse tapped delay line;
• a second filter coefficient selector that selects a second filter coefficient from the filter coefficient storage;
• a second multiplier that multiplies the second selected tap with the second filter coefficient to generate a second product;
• a third FIR unit that comprises:
• a third forward tapped delay line between a third forward input and a third forward output;
• a third reverse tapped delay line between a third reverse input and a third reverse output;
• wherein the third forward input receives the second forward output;
• wherein the third reverse output drives the second reverse input;
• a third tap selector that selects a third selected tap from the third forward tapped delay line or from the third reverse tapped delay line;
• a third filter coefficient selector that selects a third filter coefficient from the filter coefficient storage;
• a third multiplier that multiplies the third selected tap with the third filter coefficient to generate a third product;
• a muxed FIR/Hilbert unit that comprises:
• a fourth forward tapped delay line between a fourth forward input and a fourth forward output;
• a fourth reverse tapped delay line between a fourth reverse input and a fourth reverse output;
• wherein the fourth forward input receives the third forward output;
• wherein the fourth reverse output drives the third reverse input;
• wherein the fourth forward output drives the fourth reverse input;
• a fourth tap selector that selects a fourth selected tap from the fourth forward tapped delay line or from the fourth reverse tapped delay line;
• a fourth filter coefficient selector that selects a fourth filter coefficient from the filter coefficient storage;
• a shared multiplier that multiplies the fourth selected tap with the fourth filter coefficient to generate a fourth product;
• a Hilbert forward tapped delay line between a Hilbert forward input and a Hilbert forward output;
• a Hilbert reverse tapped delay line between a Hilbert reverse input and a Hilbert reverse output;
• wherein the Hilbert forward input receives a filter result;
• a Hilbert delay stage that receives the Hilbert forward output and drives the Hilbert reverse input with an inline output generated by the Hilbert delay stage;
• a Hilbert tap selector that selects a Hilbert selected tap from the Hilbert forward tapped delay line or from the Hilbert reverse tapped delay line;
• a Hilbert filter coefficient selector that selects a Hilbert filter coefficient from the Hilbert filter coefficient storage;
• wherein the shared multiplier also multiplies the Hilbert selected tap with the Hilbert filter coefficient to generate a Hilbert product;
• a filter product summer that generates a product sum of the first product, the second product, the third product, and the fourth product;
• a band pass filter accumulator that accumulates the product sum from the filter product summer to generate the filter result after the first tap selector has selected all taps in the first forward tapped delay line and in the first reverse tapped delay line;
• a Hilbert accumulator that accumulates the Hilbert product to generate a quadrature output after the Hilbert tap selector has selected all Hilbert taps in the Hilbert forward tapped delay line and in the Hilbert reverse tapped delay line;
• an absolute generator that combines the inline output and the quadrature output to generate an envelope value for the digital waveform.