Apparatus for radio telecommunication system and method of building up output power
First Claim
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1. An apparatus for a radio telecommunication system comprising:
- a modulation circuit for performing phase modulation and amplitude modulation;
a phase detection circuit for detecting a phase component of a signal modulated by said modulation circuit;
an amplitude detection circuit for detecting an amplitude component of the signal modulated by said modulation circuit;
a power amplifier circuit for amplifying power of a transmission signal and outputting the amplified transmission signal;
a feedback path for feeding a signal corresponding to an output level of said power amplifier circuit back to said amplitude detection circuit;
a variable gain amplifier circuit provided on a forward path between said amplitude detection circuit and said power amplifier circuit for generating a control voltage for amplitude control of said power amplifier circuit;
a loop filter for setting a frequency bandwidth of an amplitude control loop, said amplitude control loop including said feedback path and said forward path;
precharge means for rapidly raising an output power of said power amplifier circuit from a low power level to a power threshold for building up output power of said power amplifier circuit; and
level detecting means for detecting the level of a signal fed back through said feedback path, wherein said precharge means includes a current source and switch means connected in series with said current source, said switch means being configured to be turned on when building up the output power of said power amplifier circuit, and turned off based on the level detected by said level detecting means.
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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.
49 Citations
11 Claims
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1. An apparatus for a radio telecommunication system comprising:
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a modulation circuit for performing phase modulation and amplitude modulation; a phase detection circuit for detecting a phase component of a signal modulated by said modulation circuit; an amplitude detection circuit for detecting an amplitude component of the signal modulated by said modulation circuit; a power amplifier circuit for amplifying power of a transmission signal and outputting the amplified transmission signal; a feedback path for feeding a signal corresponding to an output level of said power amplifier circuit back to said amplitude detection circuit; a variable gain amplifier circuit provided on a forward path between said amplitude detection circuit and said power amplifier circuit for generating a control voltage for amplitude control of said power amplifier circuit; a loop filter for setting a frequency bandwidth of an amplitude control loop, said amplitude control loop including said feedback path and said forward path; precharge means for rapidly raising an output power of said power amplifier circuit from a low power level to a power threshold for building up output power of said power amplifier circuit; and level detecting means for detecting the level of a signal fed back through said feedback path, wherein said precharge means includes a current source and switch means connected in series with said current source, said switch means being configured to be turned on when building up the output power of said power amplifier circuit, and turned off based on the level detected by said level detecting means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for a radio telecommunication system comprising:
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a modulation circuit for performing phase modulation and amplitude modulation; a phase detection circuit for detecting a phase component of a signal modulated by said modulation circuit; an amplitude detection circuit for detecting an amplitude component of the signal modulated by said modulation circuit; a power amplifier circuit for amplifying power of a transmission signal and outputting the amplified transmission signal; a feedback path for feeding a signal corresponding to an output level of said power amplifier circuit back to said amplitude detection circuit; a variable gain amplifier circuit provided on a forward path between said amplitude detection circuit and said power amplifier circuit for generating a control voltage for amplitude control of said power amplifier circuit; a loop filter for setting a freguency bandwidth of an amplitude control loop, said amplitude control loop including said feedback path and said forward path; precharge means for rapidly raising an output power of said power amplifier circuit from a low power level to a power threshold for building up output power of said power amplifier circuit; and a second variable gain amplifier circuit provided on said feedback path for amplifying a signal indicative of a detected output level of said power amplifier circuit, wherein the gain of said second variable gain amplifier circuit is reduced when the output power of said power amplifier circuit needs to be increased based on an output control signal, and the gain of said second variable gain amplifier circuit is increased when the output power of said power amplifier circuit needs to be decreased based on the output control signal, and wherein said second variable gain amplifier circuit and said variable gain amplifier circuit on said forward path are controlled such that their gains change in reverse directions to each other in response to the output control signal.
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11. An apparatus for a radio telecommunication system comprising:
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a modulation circuit for performing phase modulation and amplitude modulation; a phase detection circuit for detecting a phase component of a signal modulated by said modulation circuit; an amplitude detection circuit for detecting an amplitude component of the signal modulated by said modulation circuit; a power amplifier circuit for amplifying power of a transmission signal and outputting the amplified transmission signal; a feedback path for feeding a signal corresponding to an output level of said power amplifier circuit back to said amplitude detection circuit; a variable gain amplifier circuit provided on a forward path between said amplitude detection circuit and said power amplifier circuit for generating a control voltage for amplitude control of said power amplifier circuit; a loop filter for setting a freguency bandwidth of an amplitude control loop, said amplitude control loop including said feedback path and said forward path; precharge means for rapidly raising an output power of said power amplifier circuit from a low power level to a power threshold for building up output power of said power amplifier circuit; and an oscillator for transmitter operative in response to an output of said phase detection circuit for feeding a signal in accordance with an output of said oscillator back to said phase detection circuit, said phase detection circuit being configured to compare the phase of a modulated signal from said modulation circuit with the phase of said feedback signal to output a signal in accordance with a phase difference, wherein said precharge means is configured to precharge after said phase control loop is started and stabilized.
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Specification