Design Of 24~32GHz VCO In SiGe BiCMOS Technology

With the development of mobile communication technology,the performance requirements of wireless communication devices are also increasingly demanding,and gradually develop toward the goal of ultra wideband and low power consumption.Due to the shortage of spectrum resources of current wireless communication systems,limited communication bandwidth severely restricts the development of wireless communication technologies.Besides there are abundant spectrum resources in Millimeter wave frequency range,Millimeter wave has higher anti-interference and better security than the current wireless communication band,thus becoming the hotpot of research in the industry.In addition,with the continuous development of silicon-based processes,many high-performance circuits that can only be realized through the III-V process can also be realized by a silicon-based process.As an important part of the frequency synthesizer,the voltage controlled oscillator is critical to the performance of the entire wireless communication system.Therefore voltage controlled oscillator with wide frequency range and low phase noise that woks in the millimeter wave frequency using Si-based technology is of great theoretical significance and application value.0.13?m SiGe BiCMOS process is chosen to design an ultra-wideband low phase noise millimeter-wave voltage-controlled oscillator with a frequency tuning range of 24~32 GHz in this thesis.A novel BiCMOS negative resistance circuit structure is used in this circuit design.The structure consists of a cross-coupling pair of BJT tubes operating in Class-AB and a cross-coupling pair of MOS tubes operating in Class-C,where the BJT tube flows through a small portion of the operating current to provide the required crossover for the start-up and the MOS tube flows through most of the operating current to maintain a large output swing.Since the ultra-wide frequency tuning range is the main difficulty in the design of this topic,this paper uses negative capacitance cancellation technology and switched capacitor array technology to reach this target.In order to avoid introducing additional noise to deteriorate the phase noise performance of the cavity circuit,an inductor is utilized to bias the varactor circuit.In view of reducing the parasitic effects of excess metal trace in the millimeter wave operating frequency band,this paper uses the transmission line inductance instead of the process library inductance.Considering that temperature has huge influence on Oscillator circuit performance,the voltage controlled oscillator is designed to have some margin to ensure work properly.EM simulation has shown that under TT process corner and room temperature 27oC,the voltage controlled oscillator which operates at a power supply voltage of 2V has a frequency tuning range of 23.2~32.7GHz and phase noise ?-76.6dBc/Hz@100kHz.The differential output amplitude is greater than 0.6V,and the operating current is about 42 mA,which basically meets the design specifications.The broadband low-phase-noise millimeter-wave voltage-controlled oscillator designed by this subject can be applied to the ultra-wideband millimeter-wave frequency source after being verified by the chip.