Transmitter apparatus and wireless communication apparatus
First Claim
1. A transmitter comprising:
- a quadrature modulation unit which inputs an in-phase component and a quadrature component of an input modulation signal and performs quadrature modulation;
a variable gain amplification unit which amplifies an output of the quadrature modulation unit with a predetermined gain being controlled based on a gain control signal; and
a power amplification unit which performs power amplification of an output of the variable gain amplification unit,wherein the power amplification unit has a linear mode for performing power amplification using a linear operation region in an input/output power characteristic and a saturation mode for performing power amplification using a saturation operation region in the input/output power characteristic, andwherein, if transmission output power of the power amplification unit is equal to or greater than a predetermined value, the output level of the variable gain amplification unit is adjusted, the power amplification unit is operated in the saturation mode, and a transmission output control signal amplitude-modulated based on an amplitude component of the input modulation signal is input to an output control input terminal of the power amplification unit for performing polar coordinate modulation;
if the transmission output power is less than the predetermined value, the output level of the variable gain amplification unit is adjusted, the power amplification unit is operated in the linear mode, and a transmission output control signal of a predetermined level responsive to the transmission output power is input to the output control input terminal for performing linear amplification.
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Accused Products
Abstract
A transmitter providing a wide output control variable width with high efficiency is provided. Saturation mode operation is performed in the vicinity of the maximum transmission power and the input level of a large power amplifier is enlarged and fixed. When the large power amplifier is operated in a saturation state, the amplitude component of a modulation signal is input to an R input terminal in the range responsive to an output power control level and power supply voltage of a power supply terminal is amplitude-modulated, whereby highly efficient polar coordinate modulation is performed. In smaller transmission power, linear mode operation is performed, the input level of the large power amplifier is lessened for operating the large power amplifier in the linear mode, and the power supply voltage of the power supply terminal is made variable in response to the output power control level, whereby transmission power control is performed.
39 Citations
11 Claims
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1. A transmitter comprising:
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a quadrature modulation unit which inputs an in-phase component and a quadrature component of an input modulation signal and performs quadrature modulation; a variable gain amplification unit which amplifies an output of the quadrature modulation unit with a predetermined gain being controlled based on a gain control signal; and a power amplification unit which performs power amplification of an output of the variable gain amplification unit, wherein the power amplification unit has a linear mode for performing power amplification using a linear operation region in an input/output power characteristic and a saturation mode for performing power amplification using a saturation operation region in the input/output power characteristic, and wherein, if transmission output power of the power amplification unit is equal to or greater than a predetermined value, the output level of the variable gain amplification unit is adjusted, the power amplification unit is operated in the saturation mode, and a transmission output control signal amplitude-modulated based on an amplitude component of the input modulation signal is input to an output control input terminal of the power amplification unit for performing polar coordinate modulation;
if the transmission output power is less than the predetermined value, the output level of the variable gain amplification unit is adjusted, the power amplification unit is operated in the linear mode, and a transmission output control signal of a predetermined level responsive to the transmission output power is input to the output control input terminal for performing linear amplification. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A transmitter comprising:
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a quadrature modulation unit which inputs an in-phase component and a quadrature component of an input modulation signal and performs quadrature modulation; a variable gain amplification unit which amplifies an output of the quadrature modulation unit with a predetermined gain being controlled based on a gain control signal; and a power amplification unit which performs power amplification of an output of the variable gain amplification unit, wherein the power amplification unit has a linear mode for performing power amplification using a linear operation region in an input/output power characteristic and a saturation mode for performing power amplification using a saturation operation region in the input/output power characteristic, wherein, if transmission output power of the power amplification unit is equal to or greater than a predetermined value, the output level of the variable gain amplification unit is adjusted, the power amplification unit is operated in the saturation mode, and a transmission output control signal amplitude-modulated based on an amplitude component of the input modulation signal is input to an output control input terminal of the power amplification unit for performing polar coordinate modulation;
if the transmission output power is less than the predetermined value, the output level of the variable gain amplification unit is adjusted, the power amplification unit is operated in the linear mode, and a transmission output control signal of a predetermined level responsive to the transmission output power is input to the output control input terminal for performing linear amplification,wherein the power amplification unit comprises a power supply terminal used as the output control input terminal, wherein the transmitter further comprises a power supply driver for increasing the current capacity of the signal of the predetermined level or the signal amplitude-modulated based on the amplitude component of the input modulation signal and supplying power to the power supply terminal as the transmission output control signal, and wherein the power supply driver comprises; an amplitude slice unit which slices the transmission output control signal at stepwise different voltage levels; a plurality of switching regulators for converting power supply voltage into voltages of stepwise different values; and a switch group for selecting any one of the output voltages of the plurality of switching regulators.
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Specification