VOLTAGE CONTROLLED OSCILLATOR IMPROVED IN PHASE NOISE AND FREQUENCY - VOLTAGE TUNING LINEARITY

摘要

A voltage control oscillator is provided to reduce a parasitic component of a resonant unit, thereby obtaining a more improved phase noise characteristic within a frequency tuning range. A voltage control oscillator is comprised of a voltage control oscillator power supply unit, a resonant unit and an oscillating unit. The resonant part is connected to an oscillating unit in parallel. The resonant unit outputs only a signal of a specific frequency. The oscillating unit amplifies internal noise or a small signal largely by using only DC power to generate a signal. Symmetric parallel resistances(304a,304b) are parallel connected to MOS varactors(306a,306b) and an inductor(307) respectively. A radio frequency blocking resistance(308) is serially connected to a control voltage source. The symmetric parallel resistance is made of at least a pair of parallel resistances having the same resistance size. An electric potential difference is formed between the first contact point(305a) or the second contact point(305b) and a Vctrl terminal which is a tuning voltage source.