Design of a reconfigurable phase controller for focused ultrasound therapeutic device

The use of focused ultrasound in non-invasive therapeutic applications can achieve energy concentration at a target point. Depending on the purpose of use, devices should have reconfigurable focal depths by controlling the phase or time delay of the signal applied to the transducer array. In this study, a phase controller that consists of a flash ADC, a resistor-capacitor bank phase shifter, a variable gain amplifier, and a 0°/180° phase shifter is proposed. The phase resolution has 11.25°. With every 90mV increase in input voltage, the phase of the signal is changed as much as the step of resolution, which can cover the full range from 0° to 360°. The proposed phase controller is implemented in 0.18um CMOS technology and the chip size is 1.11×0.99mm².