Abstract: An apparatus for improving transmission directivity according to an embodiment of the present invention includes a phased array probe including a channel 1 transducer and a channel 2 transducer which are arranged at intervals corresponding to a quarter wavelength at a center frequency of a guided wave pulse for long-range ultrasonic testing, and a drive unit which supplies electric pulses with opposite phases to the channel 1 transducer and the channel 2 transducer of the channel 1 transducer and the channel 2 transducer, which is disposed on the front end on the basis of an intended transmission direction, is driven with delay by a time corresponding to a quarter frequency of the center frequency than the other transducer disposed on the rear end.

Abstract: A contact shear horizontal (SH) mode guided-wave magnetostrictive transducer including: a transduction band which is disposed on a surface of an object to be tested and in which electromagnetic acoustic transduction occurs; and radio frequency (RF) coils disposed on the transduction band, wherein the transduction band includes a plate-shaped solenoid including a magnetostrictive strip in which the electromagnetic acoustic transduction for transmitting or receiving SH mode guided waves occurs, and solenoid coil wound in a spiral form along a circumference of the magnetostrictive strip so as to form a bias magnetic field in a lengthwise direction of the magnetostrictive strip, and the RF coils are used to form a dynamic magnetic field in a widthwise direction of the magnetostrictive strip or to detect a change of magnetic flux in the magnetostrictive strip.