Dual band LNA/mixer using conjugate matching for implantable biotelemetry

A fully integrated 2.4/5.2-GHz dual-band low-noise amplifier (LNA) / mixer for implantable biotelemetry is presented. By using conjugate matching technique, the proposed front-end receiver circuit integrates LNA output and mixer input into a single chip at the 2.4 GHz and 5.2 GHz ISM band. The proposed front-end circuit was designed for super-heterodyne receiver. By switching local oscillator (LO) frequency, the output of proposed circuit is the intermediate frequency at the 400 MHz frequency band. The chip has been designed and fabricated in a TSMC 0.18-mum CMOS technology. The active chip area is about 1040 mum x 760 mum. The proposed front-end circuit exhibits a 22.6 dB gain, a 4.5 dB noise figure, and OP_1dB of -15 dBm at 2.4 GHz and exhibits a 10.5 dB gain, a 5.9 dB noise figure, and OP_1dB of -14.2 dBm at 5.2 GHz. In order to achieve single chip design target, this chip input was designed with on-chip matching component. The return loss of proposed circuit reaches more than 25 dB at the both 2.4 GHz and 5.2 GHz. The proposed circuit exhibits 9.4 mW power consumption by 1.8-V supply.