A low-power, area-efficient multichannel receiver for micro MRI

Abstract

A new integrated, low-noise, low-power, and area-efficient multichannel receiver for magnetic resonance imaging (MRI) is described. The proposed receiver presents an alternative technique to overcome the use of multiple receiver front-ends in parallel MRI. The receiver consists of three main stages: low-noise pre-amplifier, quadrature down-converter, and a band pass filter (BPF). These components are used to receive the nuclear magnetic resonance signals from a 3 × 3 array of micro coils. These signals are combined using frequency domain multiplexing (FDM) method in the pre-amplifier and BPF stages, then amplified and filtered to remove any out-of-band noise before providing it to an analog-to-digital converter at the low intermediate frequency stage. The receiver is designed using a 90 nm CMOS technology to operate at the main B0 magnetic field of 9.4 T, which corresponds to 400 MHz. The receiver has an input referred noise voltage of 1.1 nV/√Hz, a total voltage gain of 87 dB, a power consumption of 69 mA from a 1 V supply voltage, and an area of 305 µm × 530 µm including the reference current and bias voltage circuits.