Apparatus for radio telecommunication system and method of building up output power
AssigneesRenesas Technology Corp., Tipcom Limited
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.
Claims4
A radio communication apparatus comprising:
- a base band unit which generates signals to be transmitted;
- a modulator which modulates the signals;
- a phase detector which detects a phase component of the signals modulated by the modulator;
- an amplitude detector which detects an amplitude component of the signal modulated by said modulator;
- an oscillator which generates a transmission signal in accordance with an output of the phase detector;
- a power amplifier which amplifies the transmission signal;
- a feedback path which supplies an output level instruction signal of the power amplifier circuit to the amplitude detector;
- and
- a forward path which supplies an output of the amplitude detector to the power amplifier for control of an amplitude of the transmission signal;
- wherein the forward path includes a loop filter which generates a voltage in response to the output of the amplitude detector;
- a first amplifier which amplifies the voltage;
- a charge pump circuit which includes a capacitor, a current source for charging said capacitor, a current sink for discharging a charge on said capacitor, and which is configured to operate the current source and the current sink in response to an output of the first amplifier to accumulate a charge on the capacitor;
- and a precharge unit which is arranged between the first amplifier and the power amplifier and which is capable of rapidly increasing a control voltage by charging the capacitor for the power amplifier to a power threshold on starting transmission.
Dependencies are inferred from the claim text.