| 摘要 |
PURPOSE: To provide an improved adopting type beam forming method using repeated phase conjugation by gradually narrowing a beam toward a dot shape using repeated correction of delay time used for focusing of an energy beam. CONSTITUTION: A converter element is excited using a delay time order corresponding to a beam focused in angleθand distance R to form a first probe beam (w=1). A receiving beam forming circuit of a front end means 16 is constituted so that a correction time of phase correction to each channel is generated from a transmission error. Signals from channels of N in number are processed into an in-phase component Im and a quadrature phase component Qm and supplied from the front end means 16 to a complex number correlation device means 18, andΔϕerrors for (N-1) pairs of respectively neighboring channels are calculated and summed up by a microcomputer to take out phase correction coefficients. This process is repeated for anglesθin all direction of the probe to generate the first group of phase correction coefficients and the delay values of RMW memory means 40 and 42. For the second probe, a new delay value is use and, further, correction is carried out using a beam with better focusing action and similarly repeated for L time corrections.
|
