In this article, a 0.25 mum monolithic complementary metal-oxide-semiconductor (CMOS) 2.4 GHz voltage-controlled oscillator has been demonstrated to have a tuning efficiency of 390 MHz/V, a phase noise of -94 dBc/Hz at a 100 kHz offset, and an output power of -3.76 dBm. In addition, a one-stage CMOS microwave power amplifier has also been presented. The transducer gain (S-21) is 15.3 dB at 2.4 GHz, and the return loss (S-11) is greater than 15 dB. This power amplifier could deliver a 16.2 dBm output power, a 15 dB power gain, and a 27% power-added efficiency.