Thesis shows the feasibility of single chip VCOs(Voltage Controlled Oscillator) using PLIC(Poly-Lithic Integrated Circuit) technology compatible with CMOS integrated circuit technology, which allows us to develop true single chip mobile communication systems. This type of VCOs are implemented and low phase noise characteristic can be obtained by using an high Q SAW(Surface Acoustic Wave) device. New method for obtaining both wide tuning range and low phase noise characteristics of SAW VCOs is proposed. Finally, marketing issues of SAW VCOs based on EC(Electronic Commerce) and KM(Knowledge Management) are discussed.