A packaged. 2.3 GHz SiGe VCO with parallel-branch inductors

In this paper, a 2.3 GHz VCO with parallel-branch inductors was designed and fabricated using a 0.8-/spl mu/m SiGe HBT process technology. Their Q-factors were higher than those of the conventional inductors. A good phase noise of -122 dBc/Hz was measured at 4 MHz offset frequency, and harmonics were suppressed by -28 dBc. The manufactured VCO core consumed 3.7 mA at 2 V supply voltage, and the VCO occupied 1.8 mm /spl times/ 1.2 mm chip area.