Design of a 432 MHz Direct Down-Conversion Gilbert Mixer for Biomedical Applications

The scaling of current biomedical technologies plays a crucial role in the new era of emerging technologies. Satisfying customer profiles and changing expectations drive these technologies to provide better comfort and precision. In concordance with this statement, capsule endoscopy encompasses the potential to be the successor of endoscopic imaging technologies concerning the evaluation criteria of effectiveness, accuracy, and patient comfort. With this reference frame, a direct down-conversion mixer at 432 MHz is designed to satisfy the requirements of the receiver section of a capsule endoscopy project. The mixer is designed in 0.18 µm CMOS node technology to provide a low double-sideband (DSB) noise figure (NF) while attaining a reasonable conversion gain (CG) and linearity (IIP3). The design offers approximately 12.9 dB DSB NF, 10 dB CG, and 11 dBm of IIP3 with a local oscillator (LO) power of -10 dBm. With a supply voltage of 1.8 V, the mixer requires a current of 3.5 mA (DC), leading to the power consumption of 6.3 mW.