title: Transceiver Design for CMUT-Based Super-Resolution Ultrasound Imaging.
abstract: A recently introduced structure for the capacitive micromachined ultrasonic transducers (CMUTs) has focused on the applications of the asymmetric mode of vibration and has shown promising results in construction of super-resolution ultrasound images. This paper presents the first implementation and experimental results of a transceiver circuit to interface such CMUT structures. The multiple input/multiple output receiver in this work supports both fundamental and asymmetric modes of operation and includes transimpedance amplifiers and low-power variable-gain stages. These circuit blocks are designed considering the trade-offs between gain, input impedance, noise, linearity and power consumption. The high-voltage transmitter can generate pulse voltages up to 60 V while occupying a considerably small area. The overall circuit is designed and laid out in a 0.35 μm CMOS process and a four-channel transceiver occupies 0.86 × 0.38 mm(2). The prototype chip is characterized in both electrical and mechanical domains. Measurement results show that each receiver channel has a nominal gain of 110 dBΩ with a 3 dB bandwidth of 9 MHz while consuming 1.02 mW from a 3.3 V supply. The receiver is also highly linear, with 1 dB compression point of minimum 1.05 V which is considerably higher than the previously reported designs. The transmitter consumes 98.1 mW from a 30 V supply while generating 1.38 MHz, 30 V pulses. The CMOS-CMUT system is tested in the transmit mode and shows full functionality in air medium.
authors.forename: Parisa
authors.initials: P
authors.lastname: Behnamfar
authors.forename: Reza
authors.initials: R
authors.lastname: Molavi
authors.forename: Shahriar
authors.initials: S
authors.lastname: Mirabbasi
mesh_terms: D000669:Amplifiers, Electronic; D025802:Electric Capacitance; D004867:Equipment Design; D006801:Humans; D021621:Imaging, Three-Dimensional; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation*