Oscillator is the source of energy for all microwave communication systems. In this research, oscillator using dielectric resonator oscillator (DRO) will be designed. Comparing to other types of oscillators, DRO has a bigger value Q factor. Designed DRO is used as the carrier for the mobile WiMAX 802.16e at frequency 2,3 GHz. The dielectric resonator Trans-Tech 8500 Series Temperature Stable will be used. To obtain a high power fundamental, it is proposed to use an additional coupling λ/4 and double-stub as matching for reducing the harmonic power. Meanwhile, to obtain low phase noise, BFR 380T BJT low-phase noise with the bias of Vcc = 5 V, Vce = 3 V, and Ic = 40 mA is used. DRO is simulated using ADS software. The phase noise is -144 dBc / Hz at 10 kHz frequency carrier with a value of Q factor is 7316. The output power at the fundamental frequency is 13 dBm and second harmonic power is -40 dBm. A Monte-Carlo Yield Analysis simulation is used to simulate the performances varied with all the variation of tolerance. It is shown from Monte-Carlo-Yield Analysis simulation, DRO with an additional coupling λ/4 producing variations as same as specification with an average percentage is 84.5%. It is also shown from the results that the designed DRO with coupling λ/4 is better than DRO without additional coupling λ/4 with single-stub matching.