WIDE-TUNING RANGE SI BIPOLAR VCOS BASED ON 3-DIMENSIONAL MMIC TECHNOLOGY

The first completely integrated silicon (Si) bipolar junction transist or (BJT) voltage-controlled oscillators (VCO's), based on three-dimens ional (3-D) monolithic-microwave integrated-circuit (MMIC) technology are presented in this paper, The 3-D MMIC technology offers the use of reactive matching in circuit design as well as GaAs MMIC construction and expands the operation frequency of Si MMIC's. Two types of VCO MM IC's using 0.5-mu m Si BJT's are presented and demonstrated, Both exhi bit a very wide frequency tuning range in the 5- and 6-GHz bands, The former offers the frequency tuning range of 33% using the base-emitter conductance operation of the BJT, which works like a varistor with a large ratio, Furthermore, the oscillation frequency is remarkably line ar against the controlled base bias, To confirm the wide-tuning abilit y of the proposed VCO at higher frequencies, a 7-GHz-band VCO is fabri cated on the same Si masterslice array used for the 5-GHz-band VCO. It achieves a 28% tuning range from 5.53 to 7.09 GHz at the collector bi as of 2 V. The latter, whose Frequency is controlled by a varactor dio de, also offers a wide tuning range from 5.15 to 6.75 GHz, The phase n oise achieved ranges from -95 dBc/Hz to -117 dBc/Hz at 1-MHz offset fr equency over the tuning range of 1.6 GHz (best phase noise performance is -90.5 dBc/Hz at 100 kHz). Measured results show that 3-D MMIC Si V CO's can be developed that yield frequencies above 7 GHz.