Abstract: This paper presents a systematic approach to designing negative-resistance and Colpitts oscillators using p-HEMT transistor. Various models such as, common source and common gate configuration in negative-resistance oscillators, common source series feedback in Colpitts oscillator is selected to analyze the output power and stability presented by the p-HEMT transistor. These oscillators are designed at 2.45 GHz frequency for which we find application in Bluetooth and Wi-Fi. In this paper, these designs are studied and tested, with their results analyzed below. Further, study proved that the Colpitts oscillator designed gave more output power and stability than the negative-resistance oscillators.