Comparison of low phase noise oscillators topologies using BAW resonator

This paper presents three different topologies of low phase noise BAW-based oscillators centered at 2.1 GHz. Two single-ended topologies: a common-base and a colpitts, as well as a colpitts differential topology have been achieved. Measurement shows that the single-ended topology is more sensitive to power supply noise, this results in an advantage for the differential topology that exhibits a phase noise 7 dB lower than the single-ended one. The best achieved phase noise was -136.5 dBc/Hz at 100 kHz offset from the carrier frequency of 2.1 GHz for a colpitts differential topology, with an output power close to -6.5 dBm and a core consumption of 21.6 mW.