US 3,939,435 A · Power amplifier

Abstract

A power amplifier device comprised of at least two amplifying circuits, each including an input, at least one voltage amplifier stage, at least one power amplifier stage adapted for signal impedance conversion, and an output, all connected in series, and further including a signal input terminal and a signal output terminal. Plural switch means are provided for selectively interconnecting the voltage amplifier stages and the power amplifier stages of the amplifying circuits for selectively establishing a parallel connected amplifying circuit, individual amplifying circuits and a balanced transformerless connection across the signal output terminals. In the parallel connected amplifying circuit, the plural switch means are operated to connect the amplifying circuit inputs in parallel, the amplifying circuit outputs in parallel and the respective amplifier stages and the respective power amplifier stages of the amplifying circuits in parallel. In the individual amplifying circuits, the plural switch means are operated to connect the amplifying circuit inputs and the amplifying outputs to corresponding signal input terminals and signal output terminals, respectively. In the balanced transformerless connection, the plural switch means are operated to connect a first amplifying circuit output to a second amplifying circuit input and to connect the amplifying circuit outputs to respective signal output terminals.

Claims11

Dependent claims

A power amplifier comprising;

a plurality of voltage amplifying means each having at least one input terminal and an output terminal;
a like plurality of signal impedance converting means, each coupled to an output terminal of a corresponding one of said voltage amplifying means;
and a plurality of switching means having plural operable conditions for selectively interconnecting the input terminals of said voltage amplifying means to each other, for selectively interconnecting the output terminals of said voltage amplifying means to each other and for selectively interconnecting the outputs of said signal impedance converting means to each other, respectively, said switching means selectively establishing in a first condition, independent series circuits each comprised of a voltage amplifying means and a corresponding signal impedance converting means;
in a second condition, parallel connected voltage amplifying means and signal impedance converting means;
and in a third condition, balanced transformerless connections between a first voltage amplifying means and a first signal impedance converting means and a second voltage amplifying means and a second signal impedance converting means.

2 more elements

A power amplifier comprising;

a plurality of voltage amplifying means each having at least one input terminal and an output terminal;
a like plurality of signal impedance converting means, each coupled to an output terminal of a corresponding one of said voltage amplifying means;
a first switch exhibiting at least a first state for selectively coupling the input terminals of a first voltage amplifying means and a second voltage amplifying means in common relation to a signal input terminal and exhibiting at least a second state for selectively coupling the respective input terminals of said first and second voltage amplifying means in independent relation to separate signal input terminals;
a second switch for selectively interconnecting the output terminals of said first and second voltage amplifying means and a third switch exhibiting at least a first state for selectively coupling the outputs of a first signal impedance converting means and a second signal impedance converting means in common relation to a signal output terminal and exhibiting at least a second state for selectively coupling said outputs of said first and second signal impedance converting means in independent relation to separate signal output terminals.

1 more element

Dependencies are inferred from the claim text.

Power amplifier

Life of this patent

Power amplifier

Life of this patent

Abstract

Claims11