High efficiency RF amplifier

Claim 2

A system as claimed in claim 1 wherein said means for providing an input signal includes means for providing a plurality of multi-bit digital words each representing a sample of a time varying analog signal, and said means for actuating includes decoder means for decoding said digital words and, for each decoded digital word, providing control signals for controlling actuation of said power amplifiers, in which said actuating means includes decoder means having N first outputs for respectively providing up to N turn on control signals for actuating one or more of said actuatable amplifiers with the number of said turn on control signals being provided being dependent upon the value of said input signal,

Claim 4

A system as claimed in claim 3 including means for providing at least one fractional RF output signal having a magnitude which is a fraction of the magnitude of said first DC voltage source, said combining means being operative to additionally combine said amplified RF output signals with said at least one fractional output signal to provide said combined RF output signal, in which said means for providing an input signal includes means for providing a plurality of multi-bit digital words each representing a sample of a time varying analog signal, and said means for actuating includes decoder means for decoding said digital words and, for each decoded digital word, providing control signals for controlling actuation of said power amplifiers.

Claim 5

An RF amplifier system comprising a plurality of DC voltage sources of different magnitudes, a RF source providing a RF drive signal, N RF actuatable power amplifiers each, when actuated, providing a RF output signal amplified in accordance with the magnitude of one of said voltage sources, means for providing an input signal, means for actuating one or more said N RF power amplifiers in dependence upon the value of said input signal, means for selectively connecting each said power amplifier with a selected one of said voltage sources so that each actuated RF power amplifier provides an output signal having a magnitude in dependence upon that of said selected DC voltage source, means for additively combining said amplified RF output signals to provide a combined RF output signal, and said means for providing an input signal includes means for providing a plurality of multi-bit digital words each representing a sample of a time varying analog signal.

Claim 6

A system as claimed in claim 5 wherein said means for actuating includes decoder means for decoding said digital words and, for each decoded digital word, providing control signals for controlling actuation of said power amplifiers, said actuating means includes decoder means having N outputs for respectively providing up to N turn on control signals for actuating one or more of said actuatable amplifiers with the number of said turn on control signals being provided being dependent upon the value of said input signal.

Claim 8

A system as claimed in claim 7 including means for providing at least one fractional RF output signal having a magnitude which is a fraction of the magnitude of said first DC voltage source, said combining means being operative to additionally combine said amplified RF output signals with said at least one fractional output signal to provide said combined RF output signal, said means for providing an input signal includes means for providing a plurality of multi-bit digital words each representing a sample of a time varying analog signal, in which said means for actuating includes decoder means for decoding said digital words and, for each decoded digital word, providing control signals for controlling actuation of said power amplifiers.

Claim 9

An RF amplifier system comprising first and second DC voltage sources of different magnitudes, a RF source providing a RF drive signal, N RF power amplifiers each for providing a RF power signal amplified in accordance with the magnitude of one of said voltage sources, N first actuatable switching means each, when actuated, connecting said first voltage source with an associated one of said N power amplifiers, N second actuatable switching means each, when actuated, connecting said second voltage source with an associated one of said N power amplifiers, means for providing an input signal, means for actuating one or more said N first switching means or one or more of said N second switching means in dependence upon the value of said input signal, means for additively combining said amplified RF output signals to provide or combine RF output signal, and said means for providing an input signal includes means for providing a plurality of multi-bit digital words each representing a sample of a time varying analog signal.

Claim 10

A system as claimed in claim 9 wherein said means for actuating includes decoder means for decoding said digital words and, for each decoded digital word, providing control signals for controlling actuation of said power amplifiers, said actuating means includes decoder means having N first output circuits associated with said N first switching means and N second output circuits associated with said N second switching means for providing turn on control signals for actuating one or more of said first switching means or one or more of said second switching means, each said digital word includes a coded control portion having a first value for selecting said first DC voltage source and a second value for selecting said second DC voltage source and means responsive to said control portion for actuating said first switching means or said second switching means in dependence upon the value of said coded control portion.

Claim 11

A system as claimed in claim 10 including means for providing at least one fractional RF output signal having a magnitude which is a fraction of the magnitude of said first DC voltage source, said combining means being operative to additionally combine said amplified RF output signals with said at least one fractional output signal to provide said combined RF output signal, said means for providing an input signal includes means for providing a plurality of multi-bit digital words each representing a sample of a time varying analog signal, and said means for actuating includes decoder means for decoding said digital words and for each decoded digital word providing control signals for controlling actuation of said power amplifiers.