Design of Low Phase Noise VCO in GSM System

The low phase noise Voltage-Controlled Oscillator (VCO) that has been used in GSM system is manufactured by circuit simulation. Under the condition of ensuring tuning range, the phase noise of VCO is effectively reduced. The designed VCO has center frequency of 825 MHz, the tuning bandwidth 63 MHz, the tuning voltage 1.8-4.5 V, the tuning sensitivity 22.5 MHz / V, and the phase noise -116 dBc/Hz/10 KHz. The adult reflow soldering process was selected. The design is low cost and suitable for large scale of production due to its little manual debugging work.