Ultra low phase noise C and X band bipolar transistors dielectric resonator oscillators

In this paper, a comparison between Si BJT and SiGe HBT devices for ultra low phase noise dielectric resonator microwave oscillators design at 4.7 GHz and 10.2 GHz is presented. Different oscillators topologies have been realized and characterized. The best measured phase noise have been achieved with the SiGe HBT devices. At C band, the best phase noise level is below -135 dBc/Hz at 10 kHz offset frequency and, at X band a value of -118 dBc/Hz at 10 kHz offset frequency has been observed.