Design of a Two-Stage Broadband Stable Power Amplifier for Low Power Wireless Telemetry Systems Using 90 nm CMOS Technology

This paper presents the design of a 0.9-1.25 GHz two-stage power amplifier using 90 nm CMOS Cadence Virtuoso for a wireless telemetry system. The system utilizes radiofrequency(RF) communication to remotely measure and transmit data for monitoring patients vital signs (pulse and respiration). The design aims to balance low power consumption with performance parameters (gain, efficiency, output power, linearity, bandwidth, and thermal stability). The proposed amplifier consists of two stages, achieving strong impedance matching with $S_{11}=-13.14 \text{dB}$ and $S_{22}=-12.66 \text{dB}$. It provides a forward transmission coefficient ($S_{21}$) of 21.90 dB to a 50Ω load at an operating frequency of 1.097 GHz with a supply voltage of 1.2 V. Within the specified bandwidth, the gain is more significant than 15 dB. Total power consumption is 153.1 mW. The amplifier exhibits a Gain-Bandwidth Product of $\text{1 8. 0 6 d B. G H z}$, which is a standard metric indicating its gain-versus-bandwidth trade-off. The stability factors ($K f>1 \& B 1 f>0$) confirm the unconditional stability. The design successfully meets the specified requirements for the intended wireless biomedical telemetry application.