| 摘要 |
A voltage controlled oscillator based on the Colpitt's design is provided. An inductor Lc is provided in parallel to one Cs of a pair of series connected capacitors Cs, Cd. The presence of the inductor Lc modifies the impedance ratio of the pair of series connected capacitors Cs, Cd by introducing a frequency dependence. This frequency dependence mitigates frequency dependent losses in a tuned circuit Lr, Ct in the voltage controlled oscillator. The invention provides an enhanced output signal over the frequency range of operation of the voltage controlled oscillator. The invention also improves the modulation of the voltage controlled oscillator's output signal which can be achieved by a separate modulation circuit Cm, Rm, Vm. The oscillator may form part of a mobile radio receiver or mobile telephone.
|
