An ISM-band direct down-conversion double-balanced mixer for biomedical applications

In this study, the design of a direct down-conversion, double-balanced Gilbert Mixer at 432 MHz is presented. The proposed circuit achieves a 13.4 dB double-sideband noise figure with an associated flicker corner frequency of 250 kHz. The conversion gain of the mixer is approximately 10.2 dB, with an IIP3 of 8.2 dBm simulated in the post-layout setup at a 1 MHz intermediate frequency. The design of the mixer has been accomplished using the UMC 180 nm CMOS process, and its layout occupies an area of 0.0135 mm(2). At the supply voltage of 1.8 V, the mixer consumes approximately 5.15 mW of power.