| 摘要 |
<p>The invention relates to a method for starting a radio transmitter. In the method a transmission frequency is generated by a phase/frequency-locked loop which comprises a phase/frequency comparator (101), a loop filter (102) and a voltage-controlled oscillator (105), and the start-up is performed by switching on an operating voltage (Ucc) to the voltage-controlled oscillator (105). To minimize the frequency error of the transmitter at the start-up, measuring data about relationship between the control voltage (Vc) of the oscillator and the output frequency (VCOFreq) of the oscillator at a specified calibration temperature are pre-stored in connection with the oscillator, and immediately before switching on the operating voltage (Ucc), control voltage (Vc) needed for locking onto the selected output frequency at the prevailing temperature is estimated and the estimated control voltage is set as the control voltage of the oscillator.</p> |
