A low-power W-band CMOS amplifier with a 0.35 V supply voltage is presented. It achieves a peak gain of 12.5 dB and consumes a power of 3.1 mW. However, the maximum available gain (MAG) or maximum stable gain (MSG) of transistor degrades markedly because of the low supply voltage and the near maximum oscillation frequency, f max . Thus, gain-boosting techniques must be employed to enhance the transistor's gain. An intuitive method, which involves drawing a set of circles, was presented to explain how the feedback network boosts the MAG to its highest value (Gmax). The method was employed in the design of the amplifier with a 0.35 V supply voltage.