Fully monolithic SiGe voltage-controlled-oscillators for wireless phone application

Based on a Clapp structure with tuneable capacitor, two fully monolithic voltage-controlled-oscillators (VCO) have been designed using a 30 GHz Ft SiGe technology. The active element of the VCOs is a common emitter SiGe heterojunction bipolar transistor. The first VCO, which is able to provide a high output power, runs in the 1490-1520 MHz range. Its control voltage sensitivity is 14 MHz/V and its output power value is 9.5 dBm (in 50 /spl Omega/ load) for a 31 mA current consumption. The second one is a double band VCO: the proposed structure has been employed in conjunction with an integrated switch. The simulated results are given in the 867-901 and 927-957 MHz ranges.