Abstract: An ultrasonic imaging system which uses transform beamforming in a two-dimensional context includes a two-dimensional array of transducer elements, a plurality of groups of local busses, and a plurality of sets of switching circuits. Each transducer element has a signal electrode coupled to a corresponding set of switching circuits which is controlled so that a particular transducer element is selectively coupled to one of the associated group of local busses. Each local bus provides an output signal that is sent from the probe to the console via a respective coaxial cable for each group of local busses. The number of connections that are necessary to be made through each coaxial cable is reduced by the ratio of the number of transducer elements coupled to a set of local busses and the number of busses in that set. Each set of local busses provides the input transform signals to one transform section of the transform preprocessor.

Abstract: A method and apparatus for remotely calibrating a system having a plurality of N elements, such as a phased array system, is provided. The method includes generating coherent signals, such as a calibration signal and a reference signal having a predetermined spectral relationship between one another. The calibration signal which is applied to each respective one of the plurality of N elements can be orthogonally encoded using a unitary transform encoder that uses a predetermined transform matrix, such as a Hadamard transform matrix or a two-dimensional discrete Fourier transform matrix, to generate a set of orthogonally encoded signals. The set of orthogonally encoded signals and the reference signal are transmitted to a remote location. The transmitted set of orthogonally encoded signals is coherently detected at the remote location. The coherently detected set of orthogonally encoded signals is then decoded using the inverse of the predetermined encoding matrix to generate a set of decoded signals.