Transistor amplifier

Claim 2

A transistor amplifier comprising: voltage supply means for supplying an operating voltage susceptible to voltage fluctuations: at least a first triode characteristic field effect transistor having gate, source and drain electrodes; means for applying said operating voltage across said drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to said gate electrode of the triode characteristic field effect transistor; and biasing circuit means for applying a gate bias voltage to said gate electrode and including compensating means connected between said voltage supply means and said gate electrode for varying said gate bias voltage in response to voltage fluctuations in said operating voltage so as to stabilize the biasing DC drain current of said triode characteristic field effect transistor in spite of said voltage fluctuations in the operating voltage therefor.

Claim 3

A transistor amplifier according to claim 1; in which said compensating means varies said gate bias voltage by an amount that is 1 Mu times the voltage fluctuation in said operating voltage, and in which Mu is the amplification constant of said triode characteristic field effect transistor.

Claim 4

A transistor amplifier according to claim 1; in which said triode characteristic field effect transistor is a P-channel type.

Claim 5

A transistor amplifier according to claim 1; in which said diode characteristic field effect transistor is an N-channel type.

Claim 6

A transistor amplifier according to claim 1; further comprising a second triode characteristic field effect transistor also having gate, source and drain electrodes, and means for applying said operating voltage across said drain and source electrodes of said second triode characteristic field effect transistor through said load; and in which said input circuit means applies said input signal to said gate electrode of said second triode characteristic field effect transistor so as to drive said first and second triode characteristic field effect transistors with a push-pull relationship therebetween, and said biasing circuit means also applies a second gate bias voltage to said gate electrode of the second triode characteristic field effect transistor with said compensating means also varying said second gate bias voltage in response to said voltage fluctuations for stabilizing the biasing DC drain current of said second triode characteristic field effect transistor.

Claim 7

A transistor amplifier according to claim 5; in which said first and second triode characteristic field effect transistors have complementary conductivites, respectively, and said operating voltage applied across said drain and source electrodes of said first field effect transistor through a load has its polarity reversed in respect to the polarity of said operating voltage as applied across said drain and source electrodes of said second field effect transistor through said load.

Claim 8

A transistor amplifier according to claim 5; in which said compensating means varies each of the first mentioned and second gate bias voltages by an amount that is 1/ Mu times the voltage fluctuaTion of said operating voltage for said first and second triode characteristic field effect transistors, with Mu being the amplification constant of said first and second transistors.

Claim 9

A transistor amplifier according to claim 5; further comprising third and fourth triode characteristic field effect transistors connected in parallel with said first and second triode characteristic field effect transistors and in push-pull relation to each other.

Claim 10

A transistor amplifier according to claim 5; in which said input circuit means includes an A-class driver stage whose output is applied to said gate electrodes of said first and second triode characteristic field effect transistors for driving the latter with push-pull operation thereof.

Claim 11

A transistor amplifier comprising: a voltage source for supplying an operating voltage susceptible to voltage fluctuations; at least a first triode characteristic field effect transistor having gate, source and drain electrodes; means for applying said operating voltage across said drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to said gate electrode of the triode characteristic field effect transistor; and biasing circuit means for applying a gate bias voltage to said gate electrode and including a transistor having first, second and third electrodes, constant voltage means, first, second, third and fourth resistors, means for applying a voltage which flucturates with said fluctuations of the operating voltage across said first and second electrodes through said first and second resistors, respectively, said third and fourth resistors being connected with said constant voltage means in a series circuit to which said voltage which fluctuates with said fluctuations of the operating voltage is also applied, said third electrode being connected to said series circuit between said third and fourth resistors, means for applying the voltage across one of said first and second resistors to said gate electrode as said gate bias voltage for the triode characteristic field effect transistor, and said resistors having respective resistance values which are selected so that said voltage across said one resistor varies in response to said fluctuations in the operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of said triode characteristic field effect transistor, for stabilizing the biasing DC drain current of said triode characteristic field effect transistor in spite of said voltage fluctuations in the operating voltage therefor.

Claim 12

A transistor amplifier comprising: a voltage source for supplying an operating voltage susceptible to voltage fluctuations; at least a first triode characteristic field effect transistor having gate, source and drain electrodes; means for applying said operating voltage across said drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to said gate electrode of the triode characteristic field effect transistor; and biasing circuit means for applying a gate bias voltage to said gate electrode and including a transistor having first, second and third electrodes, constant voltage means, first, second, third and fourth resistors, means for applying a voltage which flucturates with said fluctuations of the operating voltage across said first and second electrodes through said first and second resistors, respectively, said third and fourth resistors being connected with said constant voltage means in a series circuit to which said voltage which fluctuates with said fluctuations of the operating voltage is also applied, said third electrode being connected to said series circuit between said third and fourth resistors, means for applying the voltage across one of said first and second resistors to said gate electrode as said gate bias voltage for the triode characteristic field effect transistor, and said resistors having respective resistance values which are selected so that said voltage across said one resistor varies in response to said fluctuations in the operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of said triode characteristic field effect transistor, for stabilizing the biasing DC drain current of said triode characteristic field effect transistor in spite of said voltage fluctuations in the operating voltage therefor.

Claim 13

A transistor amplifier according to claim 10; in which said first, second and third electrodes of the transistor included in said biasing means are respectively emitter, collector and base electrodes of a bipolar transistor.

Claim 14

A transistor amplifier according to claim 10; in which said first, second, third and fourth resistors have respective resistance values r1, r2, r3 and r4 selected to satisfy the following equation:

Claim 15

A transistor amplifier comprising: a voltage source for supplying an operating voltage susceptible to voltage fluctuations; at least a first triode characteristic field effect transistor having gate, source and drain electrodes; means for applying said operating voltage across said drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to said gate electrode of the triode characteristic field effect transistor; and biasing circuit means for applying a gate bias voltage to said gate electrode and including constant voltage means, first and second resistors connected with said consTant voltage means in a series circuit, means for applying to said circuit a voltage which fluctuates with said fluctuations of the operating voltage, said gate electrode being connected to said series circuit between said first and second resistors so that the voltage across one of said resistors is applied to said gate electrode as said gate bias voltage for the triode characteristic field effect transistor, and said resistors having respective resistance values which are selected so that said voltage across said one resistor varies in response to said fluctuations in the operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of said triode characteristic field effect transistor, for stabilizing the biasing DC drain current of said triode characteristic field effect transistor in spite of said voltage fluctuations in the operating voltage therefor.

Claim 16

A transistor amplifier comprising: a voltage source for supplying an operating voltage susceptible to voltage fluctuations; at least a first triode characteristic field effect transistor having gate, source and drain electrodes; means for applying said operating voltage across said drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to said gate electrode of the triode characteristic field effect transistor; and biasing circuit means for applying a gate bias voltage to said gate electrode and including constant voltage means, first and second resistors connected with said consTant voltage means in a series circuit, means for applying to said circuit a voltage which fluctuates with said fluctuations of the operating voltage, said gate electrode being connected to said series circuit between said first and second resistors so that the voltage across one of said resistors is applied to said gate electrode as said gate bias voltage for the triode characteristic field effect transistor, and said resistors having respective resistance values which are selected so that said voltage across said one resistor varies in response to said fluctuations in the operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of said triode characteristic field effect transistor, for stabilizing the biasing DC drain current of said triode characteristic field effect transistor in spite of said voltage fluctuations in the operating voltage therefor.

Claim 17

A transistor amplifier according to claim 13; in which said first and second resistors have respective resistance values r''3 and r''4 selected to satisfy the following equation:

Claim 18

A transistor amplifier comprising: at least first and second triode characteristic field effect transistors each having gate, source and drain electrodes, a voltage source having a point of reference potential, and first, second, third and fourth terminals, with the operating voltages for said first and second triode characteristic field effect transistors appearing between said first and second terminals, respectively, and said point of reference potential and being susceptible to voltage fluctuations, and with voltages with fluctuate with said fluctuations of the operating voltages for said first and second triode characteristic field effect transistors, respectively, appearing between said third and fourth terminals, respectively, and said point of reference potential; means for applying said operating voltages for said first and second triode characteristic field effect transistors across said drain and source electrodes of the respective transistors through a load; input circuit means for applying an input signal to be amplified to the gate electrodes of said first and second triode characteristic field effect transistors, respectively, so as to drive the latter with a push-pull relationship therebetween; and biasing circuit means for applying gate bias voltages to the gate electrodes of said first and second triode characteristic field effect transistors including a first transistor having first, second and third electrodes and a first constant voltage means associated with a first set of interconnected resistors, and a second transistor having first, second and third electrodes and a second constant voltage means associated with a second set of interconnected resistors, each of said first and second sets of resistors including first, second, third and fourth resistors, said first resistors of said first and second sets being connected between said first electrodes of said first and second transistors and said third and fourth terminals, respectively, said second resistors of said first and second sets being connected between said second electrodes of said first and second transistors and said point of reference potential, said third resistors of said first and second sets being connected in series with said first and second constant voltage means, respectively, between said third electrode of said first transistor and said third terminal, and between said third electrode of said second transistor and said fourth terminal, respectively, said fourth resistors of said first and second sets being connected in series between said third electrodes of said first and second transistors, respectively, means for applying the voltage across one of said first and second resistors of said first and second sets to said gate electrodes of said first and second triode characteristic field effect transistors, respectively, as said gate bias voltages for the latter, and said resistors of said first and second sets have resistance values which are related so that said voltage across said one resistor of each of said sets varies in response to said fluctuations in the respective operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of each of said first and second triode characteristic field effect transistors, for stabilizing the biasing DC drain currents of said first and second triode characteristic field effect transistors in spite of said voltage fluctuations in the operating voltages therefor.

Claim 19

A transistor amplifier comprising: at least first and second triode characteristic field effect transistors each having gate, source and drain electrodes, a voltage source having a point of reference potential, and first, second, third and fourth terminals, with the operating voltages for said first and second triode characteristic field effect transistors appearing between said first and second terminals, respectively, and said point of reference potential and being susceptible to voltage fluctuations, and with voltages with fluctuate with said fluctuations of the operating voltages for said first and second triode characteristic field effect transistors, respectively, appearing between said third and fourth terminals, respectively, and said point of reference potential; means for applying said operating voltages for said first and second triode characteristic field effect transistors across said drain and source electrodes of the respective transistors through a load; input circuit means for applying an input signal to be amplified to the gate electrodes of said first and second triode characteristic field effect transistors, respectively, so as to drive the latter with a push-pull relationship therebetween; and biasing circuit means for applying gate bias voltages to the gate electrodes of said first and second triode characteristic field effect transistors including a first transistor having first, second and third electrodes and a first constant voltage means associated with a first set of interconnected resistors, and a second transistor having first, second and third electrodes and a second constant voltage means associated with a second set of interconnected resistors, each of said first and second sets of resistors including first, second, third and fourth resistors, said first resistors of said first and second sets being connected between said first electrodes of said first and second transistors and said third and fourth terminals, respectively, said second resistors of said first and second sets being connected between said second electrodes of said first and second transistors and said point of reference potential, said third resistors of said first and second sets being connected in series with said first and second constant voltage means, respectively, between said third electrode of said first transistor and said third terminal, and between said third electrode of said second transistor and said fourth terminal, respectively, said fourth resistors of said first and second sets being connected in series between said third electrodes of said first and second transistors, respectively, means for applying the voltage across one of said first and second resistors of said first and second sets to said gate electrodes of said first and second triode characteristic field effect transistors, respectively, as said gate bias voltages for the latter, and said resistors of said first and second sets have resistance values which are related so that said voltage across said one resistor of each of said sets varies in response to said fluctuations in the respective operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of each of said first and second triode characteristic field effect transistors, for stabilizing the biasing DC drain currents of said first and second triode characteristic field effect transistors in spite of said voltage fluctuations in the operating voltages therefor.

Claim 20

A transistor amplifier according to claim 15; in which said first, second, third and fourth resistors of each of said sets have respective resistance values r1, r2, r3 and r4 selected to satisfy the equation

Claim 21

A transistor amplifier according to claim 15; in which said fourth resistor of one of said sets is variable for relatively adjusting the gate bias voltages applied to the gate electrodes of said first and second triode characteristic field effect transistors.

Claim 22

A transistor amplifier according to claim 15; further comprising third and fourth transistors interposed between said input circuit means and said first and second triode characteristic field effect transistors, respectively, with emitter follower configurations for driving the respective triode characteristic field effect transistors.

Claim 23

A transistor amplifier comprising: at least first and second triode characteristic field effect transistors each having gate, source and drain electrodes; a voltage source having a point of reference potential, and first, second, third and fourth terminals, with operating voltages for said first and second triode characteristic field effect transistors appearing between said first terminal and said point of reference potential and between said second terminal and said point of reference potential, and with voltages which fluctuate with said fluctuations of the operating voltages for said first and second triode characteristic field effect transistors, respectively, appearing between said third and fourth terminals, respectively, and said point of reference potential; means for applying said operating voltages for said first and second triode characteristic field effect transistors across the respective drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to the gate electrodes of said first and second triode characteristic field effect transistors, respectively, so as to drive the latter with a push-pull relationship therebetween; and biasing circuit means for applying gate bias voltages to the gate electrodes of said first and second triode characteristic field effect transistors including first and second constant voltage means, and first and second sets of resistors; each of said first and second sets of resistors including first and second resistors; said first and second resistors of said first and second sets being connected in first and second series circuits with said first and second constant voltage means, respectively; said first and second series circuits being connected between said third and fourth terminals, respectively, and said point of reference potential; said gate electrodes of said first and second triode characteristic field effect transistors being connected to said first and second series circuits, respectively, betweEn said first and second resistors of the respective series circuit so that the voltages across one of said resistors in said first and second series circuits, respectively, are applied to the gate electrodes of said first and second triode characteristic field effect transistors, respectively, as said gate bias voltage for the latter; and said resistors of said first and second sets having resistance values which are related so that said voltage across said one resistor of each of said sets varies in response to said fluctuations in the respective operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of each of said first and second triode characteristic field effect transistors, for stabilizing the biasing DC drain currents of said first and second triode characteristic field effect transistors in spite of said voltage fluctuations in said operating voltages therefor.

Claim 24

A transistor amplifier comprising: at least first and second triode characteristic field effect transistors each having gate, source and drain electrodes; a voltage source having a point of reference potential, and first, second, third and fourth terminals, with operating voltages for said first and second triode characteristic field effect transistors appearing between said first terminal and said point of reference potential and between said second terminal and said point of reference potential, and with voltages which fluctuate with said fluctuations of the operating voltages for said first and second triode characteristic field effect transistors, respectively, appearing between said third and fourth terminals, respectively, and said point of reference potential; means for applying said operating voltages for said first and second triode characteristic field effect transistors across the respective drain and source electrodes through a load; input circuit means for applying an input signal to be amplified to the gate electrodes of said first and second triode characteristic field effect transistors, respectively, so as to drive the latter with a push-pull relationship therebetween; and biasing circuit means for applying gate bias voltages to the gate electrodes of said first and second triode characteristic field effect transistors including first and second constant voltage means, and first and second sets of resistors; each of said first and second sets of resistors including first and second resistors; said first and second resistors of said first and second sets being connected in first and second series circuits with said first and second constant voltage means, respectively; said first and second series circuits being connected between said third and fourth terminals, respectively, and said point of reference potential; said gate electrodes of said first and second triode characteristic field effect transistors being connected to said first and second series circuits, respectively, betweEn said first and second resistors of the respective series circuit so that the voltages across one of said resistors in said first and second series circuits, respectively, are applied to the gate electrodes of said first and second triode characteristic field effect transistors, respectively, as said gate bias voltage for the latter; and said resistors of said first and second sets having resistance values which are related so that said voltage across said one resistor of each of said sets varies in response to said fluctuations in the respective operating voltage by amounts that are 1/ Mu times said fluctuations, with Mu being the amplification constant of each of said first and second triode characteristic field effect transistors, for stabilizing the biasing DC drain currents of said first and second triode characteristic field effect transistors in spite of said voltage fluctuations in said operating voltages therefor.

Claim 25

A transistor amplifier according to claim 19; in which said first and second resistors of each of said sets have respective resistance values r''3 and r''4 selected to satisfy the equation