US Patent 7698948 Ultrasonic diagnostic apparatus

Encoded transmission and reception which reduces time side lobe are realized while suppressing increase of circuit scale. Transmission signals corresponding to a composite modulation code sequence composed from two or more modulation code sequences are outputted as transmission signals. A reception means demodulates reception signals stepwise by two or more demodulators. The demodulator can be thereby divided into two or more stages, and therefore with a circuit scale corresponding to the sum of the operation circuit numbers of two or more demodulators, time side lobe reduction effect can be obtained at a level equivalent to that obtainable with a circuit scale corresponding to the product of the operation circuit numbers of two or more demodulators.