Method for starting a radio transmitter, and a radio transmitter using a start-up estimated control voltage needed for locking onto selected output frequency

Claim 3

A method according to claim 1 further including: maintaining the temperature of the VCO substantially constant by heating said VCO using an oven.

Claim 4

A method according to claim 2, wherein: said maintaining includes maintaining the temperature of the oven substantially at said specified calibration temperature.

Claim 5

A radio transmitter for a telecommunications system for use at varying temperatures without generating at start-up frequencies different from a desired transmission frequency such as would interfere with neighboring channels, the transmitter comprising: a phase/frequency-locked loop, which comprises a phase/frequency comparator, a loop filter and a voltage-controlled oscillator (VCO), said loop being arranged to generate the transmission frequency of said radio transmitter generated by said phase/frequency-locked loop; means for switching on an operating voltage to said VCO so as to start-up said radio transmitter; storing means arranged for storing measured data about a relationship between a control voltage of said VCO and a corresponding output frequency of said VCO at a specified calibration temperature; temperature measuring means for measuring a prevailing temperature of said voltage-controlled oscillator; calculating means operatively connected to said storing means and said measuring means for estimating a start-up control voltage for said VCO on the basis of (a) a desired output frequency of said VCO, (b) said stored measured data, and (c) a difference between the prevailing temperature as measured by said temperature measuring means and said specified calibration temperature, thereby determining an estimated value for the control voltage such that a start-up frequency corresponding to said estimated start-up control voltage will not interfere with neighboring channels; and setting means responsive to said calculating means for providing a control voltage to said VCO on the basis of said estimated start-up control voltage, said means for switching on said operating voltage being responsive to said setting means, for performing said start-up immediately after the control voltage has been set to said estimated start-up control voltage value.

Claim 6

A radio transmitter for a telecommunications system for use at varying temperatures without generating at start-up frequencies different from a desired transmission frequency such as would interfere with neighboring channels, the transmitter comprising: a phase/frequency-locked loop, which comprises a phase/frequency comparator, a loop filter and a voltage-controlled oscillator (VCO), said loop being arranged to generate the transmission frequency of said radio transmitter generated by said phase/frequency-locked loop; means for switching on an operating voltage to said VCO so as to start-up said radio transmitter; storing means arranged for storing measured data about a relationship between a control voltage of said VCO and a corresponding output frequency of said VCO at a specified calibration temperature; temperature measuring means for measuring a prevailing temperature of said voltage-controlled oscillator; calculating means operatively connected to said storing means and said measuring means for estimating a start-up control voltage for said VCO on the basis of (a) a desired output frequency of said VCO, (b) said stored measured data, and (c) a difference between the prevailing temperature as measured by said temperature measuring means and said specified calibration temperature, thereby determining an estimated value for the control voltage such that a start-up frequency corresponding to said estimated start-up control voltage will not interfere with neighboring channels; and setting means responsive to said calculating means for providing a control voltage to said VCO on the basis of said estimated start-up control voltage, said means for switching on said operating voltage being responsive to said setting means, for performing said start-up immediately after the control voltage has been set to said estimated start-up control voltage value.

Claim 7

A radio transmitter according to claim 4, further comprising: means for providing said measured data.

Claim 8

A radio transmitter according to claim 4, further comprising: an oven; said VCO and said temperature measuring means being heated by said oven so as to maintain said VCO at a substantially constant temperature.