Research on the Design of an LC VCO in Mobile Digital TV Tuners
DOI:
https://doi.org/10.71222/sw5ayr98Keywords:
digital television, rf tuner, voltage-controlled oscillator, phase noise, low-power designAbstract
With the rapid growth of mobile digital television services and the continuing trend toward miniaturization and low power consumption in terminal devices, higher demands are placed on the integration level and performance of radio frequency (RF) tuners. As the core component of the phase-locked loop (PLL) frequency synthesizer within the tuner, the voltage-controlled oscillator (VCO) directly affects receiver sensitivity, signal-to-noise ratio, and overall system stability through its phase noise performance, tuning range, and power consumption. To address the combined requirements of wide frequency coverage, low phase noise, and low power operation, this paper presents a systematic design and optimization study of an LC-based VCO. First, the performance limits that the RF front-end VCO must meet are analyzed based on the system architecture and frequency planning needs of mobile digital TV tuners. Subsequently, utilizing the negative resistance model and phase noise theory, the start-up mechanism, noise sources, and tuning behavior of the LC oscillator are investigated in depth. A differential cross-coupled topology is employed to construct the LC resonant tank. By improving the inductor's quality factor, the variable capacitor structure, and the bias circuitry, phase noise is significantly reduced, and the tuning range is broadened. The design is implemented using standard CMOS technology and evaluated via PSS and Pnoise simulations. The simulation results demonstrate that the proposed LC VCO successfully meets the frequency coverage requirements of mobile digital TV tuners while exhibiting excellent phase noise and power performance, confirming its suitability for practical applications.References
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Copyright (c) 2026 Chengxi Zhang (Author)
This work is licensed under a Creative Commons Attribution 4.0 International License.
