This paper presents a low voltage, On-Off Keying (OOK) CMOS integrated transmitter for ISM 434 MHz biomedical applications using a concept of a novel self-oscillating (degenerated) active inductor. A thorough theoretical analysis of the oscillator is presented, together with simulated results using UMC 90 nm 1P9M RF process libraries. The proposed oscillator achieves an average phase noise of -93 dBc/Hz at 1 MHz offset from 434 MHz carrier frequency, with a relative tuning range of 26% to compensate for process variations. The transmitter allows modulation speeds up to 100 Mbps with RF output power of -4 dBm to 50 Î© load from 1 V power supply. Copyright Â© 2010 by Institute of Electronics, Silesian University of Technology.