Inherent delay line ultrasonic transducer and systems

An ultransonic transmitting and/or receiving transducer for generating and/or receiving compressional acoustic waves for use in ultrasonic examination of an object, said transducer comprising,

• a piezoelectric member having first and second opposite faces,
• first and second electrode means disposed on said first and second faces, respectively,
• at least one of said electrode means being in the form of an elongated strip conductor which, together with the other of said electrode means comprises a delay line for inherent delay in the propagation of electromagnetic waves therealong through distributed capacitance and inductance of the delay line,
• means for acoustically coupling one face of said piezoelectric member to an object under ultrasonic examination,
• said piezoelectric member having a substantially cylindrical shape, and said elongated strip conductor having a substantially spiral shape with the inner end of the spiral-shaped conductor terminating adjacent the center of one face of said piezoelectric member, the width of said spiral-shaped conductor tapering in going from one end to the other end thereof for modification of delay line impedance as the conductor width changes for control of apodization of the ultrasonic transducer.

An ultrasonic transmitting and/or receiving transducer for generating and/or receiving compressional acoustic waves for use in ultrasonic examination of an object, said transducer comprising,

• a piezoelectric member having first and second opposite faces,
• first and second electrode means disposed on said first and second faces, respectively,
• at least one of said electrode means being in the form of an elongated strip conductor which, together with the other of said electrode means comprises a delay line for inherent delay in the propagation of electromagnetic waves therealong through distributed capacitance and inductance of the delay line,
• means for acoustically coupling one face of said piezoelectric member to an object under ultrasonic examination,
• said piezoelectric member having a substantially cylindrical shape, and said elongated strip conductor having a substantially spiral shape with the inner end of the spiral-shaped conductor terminating adjacent the center of one face of said piezoelectric member,
• means for connecting the outer end of said spiral-shaped conductor to transmitter means for energizing said transducer for beaming focused ultrasonic energy into said object, and
• high permeability means adjacent said elongated strip conductor for increasing the distributed impedance of the delay line thereby reducing the propagation rate of electromagnetic waves therealong and moving the beam focus closer to said transducer.

An ultrasonic transmitting and/or receiving transducer for generating and/or receiving compressional acoustic waves for use in ultrasonic examination of an object, said transducer comprising,

• a piezoelectric member having first and second opposite faces,
• first and second electrode means disposed on said first and second faces, respectively,
• at least one of said electrode means being in the form of an elongated strip conductor which, together with the other of said electrode means comprises a delay line for inherent delay in the propagation of electromagnetic waves therealong through distributed capacitance and inductance of the delay line,
• means for acoustically coupling one face of said piezoelectric member to an object under ultrasonic examination, and
• high permeability means adjacent said elongated strip conductor for increasing the distributed inductance of the delay line thereby reducing the propagation rate of electromagnetic waves therealong.

An ultrasonic transmitting and/or receiving transducer for generating and/or receiving compressional acoustic waves for use in ultrasonic examination of an object, said transducer comprising,

• a piezoelectric member of substantially cylindrical shape and having first and second opposite faces,
• first and second electrode means disposed on said first and second faces, respectively,
• at least one of said electrode means being in the form of an elongated strip conductor which, together with the other of said electrode means comprises a delay line for inherent delay in the propagation of electromagnetic waves therealong through distributed capacitance and inductance of the delay line, said one electrode means comprising a plurality of concentric spiral-shaped conductors,
• means for acoustically coupling one face of said piezoelectric member to an object under ultrasonic examination, and
• means for electrically connecting said concentric spiral-shaped conductors in shunt with the outer ends thereof electrically interconnected and with the inner ends thereof electrically interconnected.