A low power, area efficient fpga based beamforming technique for 1-D CMUT arrays

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Ultrasound Technology

Background:

• Capacitive Micromachined Ultrasonic Transducers (CMUTs) are crucial for ultrasound imaging.
• Existing digital beamforming techniques often face limitations in power and area efficiency, especially for low-frequency arrays.
• Optimizing beamformer design is essential for developing compact and low-power ultrasonic systems.

Purpose of the Study:

• To develop a low-power, area-efficient digital beamformer for 1-D linear CMUT arrays operating at low frequencies (2MHz).
• To leverage the inherent symmetry of CMUT arrays to minimize resource utilization.
• To provide a competitive alternative to conventional square root-based beamforming algorithms.

Main Methods:

• Exploiting the symmetry of the CMUT array in the beamforming logic design.
• Simulation and verification using MATLAB and an Arbitrary Waveform Generator (AWG).
• Implementation and functional testing on a Xilinx Spartan 3E FPGA kit.
• Targeting an Application Specific Integrated Circuit (ASIC) platform using UMC 90nm technology.

Main Results:

• The proposed digital beamformer architecture demonstrates significantly reduced power and area consumption compared to conventional methods.
• For a 64-element CMUT array, the architecture achieved 1.2895 mW power and 47134.4 μm² area.
• Successful functional verification on FPGA, indicating readiness for ASIC implementation.

Conclusions:

• The developed digital beamformer offers a substantial improvement in power and area efficiency for low-frequency CMUT arrays.
• The symmetry-exploiting design is a key factor in achieving these performance gains.
• This architecture is well-suited for integration into power-sensitive and space-constrained ultrasonic devices.