Dual-band, dual-mode power amplifier
First Claim
1. A power amplifier circuit for amplifying RF signals, said power amplifier circuit selectively operable in a linear mode or a nonlinear mode, comprising:
- a first amplifier;
a second amplifier;
a diplex matching circuit coupled to said first amplifier, said diplex matching circuit having first and second outputs; and
switching circuitry, coupled to the first output of said diplex matching circuit and the output of said low pass matching circuit, for selectively coupling said first diplex matching circuit output or said low pass matching circuit output to an output line when said amplifier circuit is selectively placed in said linear mode or said nonlinear mode, respectively.
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Accused Products
Abstract
A power amplifier circuit for a radio transceiver has a linear mode amplifier and a saturated (nonlinear) mode amplifier, a diplex matching circuit coupled to the linear mode amplifier for impedance matching and for separating transmitted signals in a plurality of frequency bands, a low pass matching circuit coupled to the output of the saturated mode amplifier and means for selectably placing the power amplifier circuit in a linear mode for or a saturated mode, corresponding to digital and analog modes of operation of the cellular telephone, respectively. In linear or digital mode, the linear amplifier is biased in the on state and the saturated mode amplifier may be biased in the off state. Similarly, in the saturated or analog mode of operation, the saturated mode amplifier is biased in the on state and the linear amplifier may be biased in the off state. The amplifier circuit may include a switch or circuit, coupled to an output of the diplex matching circuit and the output of the low pass matching circuit, for selectably coupling the first diplex matching circuit output or the low pass matching circuit output to an output line when the amplifier circuit is selectably placed in linear mode or saturated mode, respectively.
79 Citations
13 Claims
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1. A power amplifier circuit for amplifying RF signals, said power amplifier circuit selectively operable in a linear mode or a nonlinear mode, comprising:
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a first amplifier; a second amplifier; a diplex matching circuit coupled to said first amplifier, said diplex matching circuit having first and second outputs; and switching circuitry, coupled to the first output of said diplex matching circuit and the output of said low pass matching circuit, for selectively coupling said first diplex matching circuit output or said low pass matching circuit output to an output line when said amplifier circuit is selectively placed in said linear mode or said nonlinear mode, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A power amplifier circuit for amplifying RF signals, comprising:
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a first amplifier; a second amplifier; a diplex matching circuit coupled to said first amplifier, said diplex matching circuit having first and second outputs; a low pass matching circuit coupled to the output of said second amplifier; means for selectively placing said power amplifier circuit in a digital or analog mode of operation, wherein said first amplifier is biased for operation in linear mode when said amplifier circuit is selectively placed in said digital mode of operation and said second amplifier is biased for operation in nonlinear mode when said amplifier circuit is selectively placed in said analog mode of operation; and means, coupled to the first output of said diplex matching circuit and the output of said low pass matching circuit, for selectably coupling said first diplex matching circuit output or said low pass matching circuit output to an output line when said amplifier circuit is selectably placed in said digital or analog mode of operation, respectively.
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12. A cellular telephone operable in a plurality of modes to receive and transmit RF signals in a plurality of frequency bands, comprising:
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a first amplifier; a second amplifier; a diplex matching circuit coupled to said first amplifier, said diplex matching circuit having first and second outputs; a low pass matching circuit coupled to the output of said second amplifier; means for selectively placing said power amplifier circuit in a digital or analog mode of operation, wherein said first amplifier is biased for operation in linear mode when said amplifier circuit is selectively placed in said digital mode of operation and said second amplifier is biased for operation in nonlinear mode when said amplifier circuit is selectively placed in said analog mode of operation; and means, coupled to the first output of said diplex matching circuit and the output of said low pass matching circuit, for selectively coupling said first diplex matching circuit output or said low pass matching circuit output to an output line when said amplifier circuit is selectively placed in said digital or analog mode of operation, respectively.
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13. A power amplifier circuit for amplifying RF signals, said power amplifier circuit selectively operable in a linear mode or a nonlinear mode, said circuit comprising;
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a) a first amplifier; b) a second amplifier; c) an RF input port; d) a first switch selectively connecting said RF input port to one of said first and second amplifiers; e) an analog matching circuit operatively connected to said first amplifier; f) a diplex matching circuit coupled to said second amplifier, said matching circuit having a first output for outputting signals in a first frequency band and a second output for outputting signals in a second frequency band; g) a diplexer connected to said first output of said diplex matching circuit; h) a duplexer; i) a second switch selectively connecting said duplexer to one of said second output of said diplex matching circuit and said analog matching circuit; and j) an antenna operatively connected to said diplexer and said duplexer.
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Specification