Method and apparatus for complex bandpass filtering and decimation in ultrasound beamformer
US5797847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1996 |
| Grant date | Aug 25, 1998 |
| Priority date | — |
| Expiry date | Dec 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/044
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A phased array sector scanning ultrasonic system includes a separate beamformer channel for each respective element in an ultrasonic transducer array. Each beamformer channel has a three-stage complex FIR filter downstream of an analog-to-digital converter. Each filter circuit stage has a register pipeline, an in-phase FIR filter and a quadrature FIR filter. The first stage only has real samples, so there is a single pipeline. The other stages have complex inputs composed of in-phase (real) and quadrature (imaginary) samples, requiring a pipeline for each. Each register pipeline is made up of a multiplicity of registers connected in series. The number of registers in a given pipeline must equal the number of taps being used on the FIR filter immediately downstream of the register pipeline. The registers are clocked in synchronism and store successive echo data samples. Each register in the pipeline has an output connected to a respective tap of the corresponding FIR filter. In the second and third stages, the taps on the FIR filters receive data samples consisting of a real data sample from the I pipeline and/or an imaginary data sample from the Q pipeline. These complex data sampl…
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