Metastructure for impedance matching for multilayer or non-uniform barrier, ultrasonic probe comprising same, and ultrasonic image diagnosis apparatus comprising same

A metastructure for impedance matching,

• wherein the metastructure is arranged to be spaced apart from a surface of a multilayer barrier by a predetermined matching distance toward an ultrasonic transducer, in an intermediate material provided between the ultrasonic transducer and the multilayer barrier,
• wherein the metastructure is configured to minimize a reflection coefficient of a system transfer matrix which consisting of a product of a transfer matrix expressed as a characteristic impedance and a phase change of each of the metastructure disposed at the matching distance, the intermediate material and the multilayer barrier.

A metastructure for impedance matching, the metastructure being disposed within an intermediate material provided between an ultrasonic transducer and a barrier, the metastructure comprising:

• a first metastructure spaced apart by a first matching distance from a first surface area of the barrier toward the transducer, and configured to minimize a difference between a first surface impedance at the first matching distance and a characteristic impedance of the intermediate material;
• and
• a second metastructure spaced apart by a second matching distance from a second surface area of the barrier adjacent to the first surface area toward the transducer, and configured to minimize a difference between a second surface impedance at the second matching distance and a characteristic impedance of the intermediate material.

A metastructure for impedance matching, the metastructure being disposed within an intermediate material provided between an ultrasonic transducer and a barrier, the metastructure comprising:

• a first metastructure spaced apart by a first matching distance from a first surface area of the barrier toward the transducer, and configured to minimize a reflection coefficient of a first system transfer matrix which consisting of a product of a first transfer matrix expressed as a characteristic impedance and a phase change of each of the first metastructure disposed at the first matching distance, the intermediate material and the barrier;
• and
• a second metastructure spaced apart by a second matching distance from a second surface area of the barrier adjacent to the first surface area toward the transducer, and configured to minimize a reflection coefficient of a second system transfer matrix which consisting of a product of a second transfer matrix expressed as a characteristic impedance and a phase change of each of the second metastructure disposed at the second matching distance, the intermediate material and the barrier.