Which transducer type is composed of separate transmit and receiver elements housed in a single transducer, with frequency determined by the machine's electrical frequency and lacking backing material, resulting in a narrow bandwidth?

Which transducer type is composed of separate transmit and receiver elements housed in a single transducer, with frequency determined by the machine's electrical frequency and lacking backing material, resulting in a narrow bandwidth?

• A. Continuous Wave Transducers
• B. Linear Sequenced Array
• C. Convex Sequential Array
• D. Linear Phased Array

Answer: (A)

Continuous-wave transducers are built with two separate crystal elements—one dedicated to transmitting and one dedicated to receiving—housed together in a single probe. The frequency is set by the electrical oscillator driving the transmitter, not by the crystal’s own resonant frequency, which allows the machine to choose the transmit frequency independently. Because there is no backing material to damp the crystals, the transducer resonates strongly at its chosen frequency, yielding a very high quality factor and a narrow bandwidth. This combination—separate transmit and receive elements in one housing, frequency dictated by the electrical drive, and lack of backing material producing a narrow bandwidth—defines the continuous-wave type. Other transducer types used for imaging rely on backing to shorten pulses and broaden bandwidth and usually use the same element for both transmission and reception, which is why they don’t match this description.

Continuous-wave transducers are built with two separate crystal elements—one dedicated to transmitting and one dedicated to receiving—housed together in a single probe. The frequency is set by the electrical oscillator driving the transmitter, not by the crystal’s own resonant frequency, which allows the machine to choose the transmit frequency independently. Because there is no backing material to damp the crystals, the transducer resonates strongly at its chosen frequency, yielding a very high quality factor and a narrow bandwidth. This combination—separate transmit and receive elements in one housing, frequency dictated by the electrical drive, and lack of backing material producing a narrow bandwidth—defines the continuous-wave type. Other transducer types used for imaging rely on backing to shorten pulses and broaden bandwidth and usually use the same element for both transmission and reception, which is why they don’t match this description.