Ultrasound radiating and receiving device

An ultrasound radiating and receiving device comprising.

• a first piezoelectric substrate;
• a first interdigital arrangement of two comb-shaped electrodes formed on a lower end surface of said first piezoelectric substrate, a lower end surface of said first interdigital arrangement being in contact with a surface-part of a material;
• a second piezoelectric substrate;
• a second interdigital arrangement of two comb-shaped electrodes formed on an upper end surface of said second piezoelectric substrate;
• and
• a counter electrode cemented between said first- and second piezoelectric substrates,
• one of said two comb-shaped electrodes in said first interdigital arrangement and said counter electrode receiving an input electric signal, radiating a longitudinal wave into said material through said surface-part of said material along the direction vertical to said lower end surface of said first piezoelectric substrate, and making an object located inside said material reflect said longitudinal wave back,
• one of said two comb-shaped electrodes in said second interdigital arrangement and said counter electrode detecting a reflected longitudinal wave as a delayed electric signal.

An ultrasound radiating and receiving device comprising:

• a first piezoelectric substrate;
• a first comb-shaped electrode formed on a lower end surface of said first piezoelectric substrate, a lower end surface of said first comb-shaped electrode being in contact with a surface-part of a material,
• a second piezoelectric substrate;
• a second comb-shaped electrode formed on an upper end surface of said second piezoelectric substrate;
• and
• a counter electrode cemented between said first- and second piezoelectric substrates,
• said first comb-shaped electrode and said counter electrode receiving an input electric signal, radiating a longitudinal wave into said material through said surface-part of said material along the direction vertical to said lower end surface of said first piezoelectric substrate, and making an object located inside said material reflect said longitudinal wave back,
• said second comb-shaped electrode and said counter electrode detecting a reflected longitudinal wave as a delayed electric signal.