An ultrasonic low-noise analog beamformer for Doppler acquisition achieves
high sensitivity by translating the frequency of the ultrasound echoes to
an intermediate frequency, which is well above of the 1/f corner. This is
accomplished by beamforming the downconverted RF signals instead of using
their baseband representation. The baseband conversion, succeeding the
beamformation, also incorporates the steps of clutter filtering and
anti-aliasing. The invention is particularly suitable for low-voltage
process technologies that support broadband applications.