Abstract—A variable-gain 0.18 μm Complementary Metal- Oxide-Semiconductor (CMOS) Low-Noise Amplifier (LNA) for Medical Device Radiocommunications Service (MedRadio) applications has been designed and verified through simulations in Cadence IC5 with Silterra’s C18G CMOS technology Process Design Kit. Unlike other MedRadio LNAs from previous works, this proposed LNA can vary its gain from just above 10 dB to nearly 30 dB. It consists of three stages; the input-matching stage, the interstage buffer, and the gain-varying stage. The input-matching stage provides an input impedance match and drives the initial gain of the LNA. The inter-stage buffer isolates the input-matching stage from the gain-varying stage. The overall gain of the LNA can be varied and is determined by the variable biasing of the driving transistors of the gainvarying stage. On post-layout simulations with a sourcefollower output buffer, this LNA exhibits a wide-ranging gain from 11.2 dB at 0.49 mW DC power consumption to 29.1 dB at 1.34 mW DC power consumption.