Electronic signal amplifier

Claim 2

An electronic signal amplifier comprising: a first transistor having base, emitter and collector electrodes, means for supplying input signals to said base electrode, a load circuit coupled to said emitter electrode, a source of operating potential, a second transistor having base, emitter and collector electrodes and arranged in a common emitter configuration, means for direct current coupling said base and emitter electrodes of said second transistor between said collector of said first transistor and said source, third and fourth transistors, each having base, emitter and collector electrodes and each being arranged in a common emitter configuration, means for direct current coupling the base of said third transistor to the collector of said second transistor, means for direct current coupling the base of said fourth transistor to the collector of said third transistor, and means for coupling the collector-emitter circuit of said fourth transistor across said load circuit.

Claim 3

An electronic signal amplifier according to claim 1 wherein: said first and fourth transistors are of one type conductivity and said second transistor is of opposite type conductivity.

Claim 4

An electronic signal amplifier according to claim 2 wherein: said third transistor is of said opposite type conductivity and the emitter electrode of said third transistor is direct current coupled to said source.

Claim 5

An electronic signal amplifier according to claim 3 wherein: said means for coupling the base of said third transistor to the collector of said second transistor comprises a resistor coupled from said last-named collector to the emitter of said fourth transistor.

Claim 6

An electronic signal amplifier according to claim 4 wherein: said means for coupling the base of said third transistor to the collector of said second transistor further comprises a first diode-connected transistor connected between the base and emitter electrodes of said third transistor, and said means for coupling the base of said second transistor to the collector of said first transistor comprises a second diode-connected transistor connected between base and emitter electrodes of said second transistor.

Claim 7

An electronic signal amplifier according to claim 2 wherein: said third transistor is of said one type conductivity and the emitter of said third transistor is direct current coupled to said emitter of said fourth transistor.

Claim 8

An electronic signal amplifier according to claim 6 wherein: said means for coupling the base of said fourth transistor to the collector of said third transistor comprises a resistor coupled from said last-named collector to said source.

Claim 9

An electronic signal amplifier according to claim 7 wherein: said means for coupling the base of said third transistor to the collector of said second transistor comprises a first diode-connected transistor connected between the base and emitter electrodes of said third transistor, and said means for coupling the base of said second transistor to the collector of said first transistor comprises a second diode-connected transistor having base and emitter electrodes connected between the base and emitter electrodes of said second transistor.

Claim 10

An electronic signal amplifier comprising: a first transistor having base, emitter and collector electrodes, a source of operating potential having supply and reference terminals, means coupled between said base electrode and said reference terminal for supplying input signals to said first transistor, a load circuit coupled between said emitter electrode and said reference terminal, a second transistor having emitter and collector electrodes coupled across said load circuit and a base electrode, first current repeater means, including at least one transistor base-emitter junction coupled between said colLector electrode and said supply terminal and a third transistor having base and emitter electrodes coupled to corresponding electrodes of said one transistor and a collector electrode for producing feedback current proportional to collector current of said first transistor, and means coupled to said first current repeater means and responsive to said feedback current for providing control signals between said base and emitter electrodes of said second transistor so as to reduce variations of collector current of said first transistor caused by said input signals while coupling sufficient current to said load circuit to reproduce variations in said input signal across said load circuit.

Claim 11

An electronic signal amplifier comprising: a first transistor having base, emitter and collector electrodes, a source of operating potential having supply and reference terminals, means coupled between said base electrode and said reference terminal for supplying input signals to said first transistor, a load circuit coupled between said emitter electrode and said reference terminal, a second transistor having emitter and collector electrodes coupled across said load circuit and a base electrode, first current repeater means, including at least one transistor base-emitter junction coupled between said colLector electrode and said supply terminal and a third transistor having base and emitter electrodes coupled to corresponding electrodes of said one transistor and a collector electrode for producing feedback current proportional to collector current of said first transistor, and means coupled to said first current repeater means and responsive to said feedback current for providing control signals between said base and emitter electrodes of said second transistor so as to reduce variations of collector current of said first transistor caused by said input signals while coupling sufficient current to said load circuit to reproduce variations in said input signal across said load circuit.

Claim 12

An electronic signal amplifier according to claim 9 wherein: said means for providing control signals comprise second current repeater means having an input coupled to said first current repeater means and an output coupled to said base electrode of said second transistor.

Claim 13

An electronic signal amplifier comprising: a first transistor having base, emitter and collector electrodes, a source of operating potential having supply and reference terminals, means coupled between said base electrode and said reference terminal for supplying input signals to said first transistor, a load circuit coupled between said emitter electrode and said reference terminal, first current repeater means, including at least one transistor base-emitter junction coupled between said collector electrode and said supply terminal, for producing feedback current proportional to collector current of said first transistor, a second transistor having emitter and collector electrodes coupled across said load circuit and a base electrode, and means comprising a second current repeater means, having an input coupled to said first current repeater means and an output coupled to said base electrode of said second transistor, responsive to said feedback current for providing control signals between said base and emitter electrodes of said second transistor so as to reduce variations of collector current of said first transistor caused by said input signals while coupling sufficient current to said load circuit to reproduce variations in said input signals across said load circuit, said first and second current repeater means each including at least two transistors having base-emitter junctions connected in parallel in which input current is supplied and an output collector electrode from which output current proportional to said input current is provided, said two transistors of each said repeater means exhibiting proportionally related conduction characteristics.

Claim 14

An electronic signal amplifier comprising: a first transistor having base, emitter and collector electrodes, a source of operating potential having supply and reference terminals, means coupled between said base electrode and said reference terminal for supplying input signals to said first transistor, a load circuit coupled between said emitter electrode and said reference terminal, first current repeater means, including at least one transistor base-emitter junction coupled between said collector electrode and said supply terminal, for producing feedback current proportional to collector current of said first transistor, a second transistor having emitter and collector electrodes coupled across said load circuit and a base electrode, and means comprising a second current repeater means, having an input coupled to said first current repeater means and an output coupled to said base electrode of said second transistor, responsive to said feedback current for providing control signals between said base and emitter electrodes of said second transistor so as to reduce variations of collector current of said first transistor caused by said input signals while coupling sufficient current to said load circuit to reproduce variations in said input signals across said load circuit, said first and second current repeater means each including at least two transistors having base-emitter junctions connected in parallel in which input current is supplied and an output collector electrode from which output current proportional to said input current is provided, said two transistors of each said repeater means exhibiting proportionally related conduction characteristics.

Claim 15

An electronic signal amplifier according to claim 11 wherein: said first and second transistors are of a first type conductivity and said two transistors of said first current repeater means are of a second type conductivity.

Claim 16

An electronic signal amplifier according to claim 12 wherein: said two transistors of said second current repeater means are of said first type conductivity and include emitter electrodes connected to said reference terminal, and said two transistors of said first current repeater means each include emitter electrodes direct current coupled to said supply terminal and base electrodes direct current coupled to said collector of said first transistor.

Claim 17

An electronic signal amplifier according to claim 13 wherein: one of said two transistors in each of said first and second current repeater means is connected as a diode.

Claim 18

An electronic signal amplifier according to claim 14 and further comprising: a resistor coupled between said potential source terminal and one of said output collector electrodes, said resistor being further coupled to said base electrode of said second transistor.