Two types of microwave oscillators, Colpitts and Pierce microwave oscillators, are designed based on the high Q and multimode resonant characteristics of highovertone bulk acoustic resonator (HBAR). The fundamental frequency microwave band signals can be output directly by using HBAR and LC components to consist of feedback oscillating loop with amplifier circuit.Theoutput signal frequency of Colpitts oscillator is 980 MHz with output signal power of -4.92 dBm and phase noise of -119.64 dBc/Hz at 10 kHz offset. And the output signal frequency of the Pierce oscillator circuit is up to 2.962 GHz with output signal power of -9.77 dBm and phase noise of -112.30 dBc/Hz at 10 kHz offset.