Apparatus for radio telecommunication system and method of building up output power
OwnerKazuhisa Okada, Kazuhiko Hikasa +1inventors
InventorsKazuhisa Okada, Kazuhiko Hikasa, Patrick Wurm
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Abstract
A polar loop based radio telecommunication apparatus which has a phase control loop for controlling the phase of a carrier outputted from an oscillator for transmitter, and an amplitude control loop for controlling the amplitude of a transmission output signal outputted from a power amplifier circuit, wherein precharge means is provided on a forward path from a current source, through the power amplifier circuit, to a detection circuit, forming the amplitude control loop, for rapidly increasing a control voltage for the power amplifier circuit to a power threshold upon starting transmission.
Claims10
-12. (canceled)
A method of building up output power in a radio telecommunication apparatus having a phase control loop for controlling the phase of a carrier outputted from an oscillator for a transmitter, and an amplitude control loop for controlling the amplitude of a transmission output signal outputted from a power amplifier circuit, said method comprising the steps of:
- starting first said phase control loop;
- opening said amplitude control loop after said phase control loop is stabilized to perform a precharge for raising the control signal of the power amplifier so that the output power rises up to a power threshold;
- terminating said precharge when said forward path reaches the power threshold;
- and
- closing said amplitude control loop to build up the output power of said power amplifier circuit.
An apparatus for controlling a power amplifier operating on a carrier signal, the apparatus comprising a feedback path for conveying a sample of the output of the power amplifier to comparison means arranged to output an amplitude control signal related to the difference in amplitude of said sampled amplifier output and a modulation signal to be amplitude-modulated onto the carrier signal, and a forward path for conveying the amplitude control signal to an input of the power amplifier to control the power amplification, wherein the forward path includes control means which operates at start up of the power amplifier under low power conditions to remove the amplitude control signal from the input and apply a ramping voltage to the input to increase the speed with which the output of the power amplifier reaches a power threshold, at which the ramping voltage is terminated and the amplitude control signal is re-applied to the input of the power amplifier.
Dependencies are inferred from the claim text.