A 1.3 mW low-IF, current-reuse, and current-bleeding RF front-end for the MICS band with sensitivity of -97 dbm

A low-power, low-intermediate frequency (IF) radio frequency (RF) front-end, including low-noise amplifier (LNA) and mixer for the medical implant communications service (MICS) RF band, is presented. The frequencies of LNA and mixer range from 402 MHz to 405 MHz, while the IF of the mixer is 450 KHz. Current-reuse, back-gate coupling, current-bleeding, and feedback circuit design techniques are utilized in the LNA design to achieve 10 dB of gain and the required noise figure (NF) under the low power consumption of 0.94 mW. By contrast, the Gilbert-type mixer generates 20 dB of conversion gain by using current-reuse, back-gate coupling, and current-bleeding techniques. The front-end is operated using a 1.8 V power supply and is capable of achieving a $-$ 97 dBm sensitivity using quadrature phase shift keying modulation while consuming 1.3 mW. The proposed front-end is implemented in TSMC 0.18 $\mu{\rm m}$ CMOS process with a total area of 1.4 mm $\times$ 1.2 mm. The gain enhancement technique has been substantially optimized compared with previous works and measurement results indicate that the front-end obtains the highest figure of merit compared with previous works.